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• This comparison shows the changes necessary to convert path

  → /tags/0.1.1/kernel/generic/src/mm @ 1963

  → /tags/0.1.1/kernel/generic/src/mm @ 1968

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Ignore whitespace Rev 1963 → Rev 1968

/tags/0.1.1/kernel/generic/src/mm/as.c
0,0 → 1,963
/*
* Copyright (C) 2001-2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file as.c
* @brief Address space related functions.
*
* This file contains address space manipulation functions.
* Roughly speaking, this is a higher-level client of
* Virtual Address Translation (VAT) subsystem.
*
* Functionality provided by this file allows one to
* create address space and create, resize and share
* address space areas.
*
* @see page.c
*
*/
#include <mm/as.h>
#include <arch/mm/as.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <mm/slab.h>
#include <mm/tlb.h>
#include <arch/mm/page.h>
#include <genarch/mm/page_pt.h>
#include <genarch/mm/page_ht.h>
#include <mm/asid.h>
#include <arch/mm/asid.h>
#include <synch/spinlock.h>
#include <adt/list.h>
#include <adt/btree.h>
#include <proc/task.h>
#include <proc/thread.h>
#include <arch/asm.h>
#include <panic.h>
#include <debug.h>
#include <print.h>
#include <memstr.h>
#include <macros.h>
#include <arch.h>
#include <errno.h>
#include <config.h>
#include <arch/types.h>
#include <typedefs.h>
#include <syscall/copy.h>
#include <arch/interrupt.h>
as_operations_t *as_operations = NULL;
/** Address space lock. It protects inactive_as_with_asid_head. */
SPINLOCK_INITIALIZE(as_lock);
/**
* This list contains address spaces that are not active on any
* processor and that have valid ASID.
*/
LIST_INITIALIZE(inactive_as_with_asid_head);
/** Kernel address space. */
as_t *AS_KERNEL = NULL;
static int area_flags_to_page_flags(int aflags);
static int get_area_flags(as_area_t *a);
static as_area_t *find_area_and_lock(as_t *as, __address va);
static bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area);
/** Initialize address space subsystem. */
void as_init(void)
{
as_arch_init();
AS_KERNEL = as_create(FLAG_AS_KERNEL);
if (!AS_KERNEL)
panic("can't create kernel address space\n");
}
/** Create address space.
*
* @param flags Flags that influence way in wich the address space is created.
*/
as_t *as_create(int flags)
{
as_t *as;
as = (as_t *) malloc(sizeof(as_t), 0);
link_initialize(&as->inactive_as_with_asid_link);
spinlock_initialize(&as->lock, "as_lock");
btree_create(&as->as_area_btree);
if (flags & FLAG_AS_KERNEL)
as->asid = ASID_KERNEL;
else
as->asid = ASID_INVALID;
as->refcount = 0;
as->page_table = page_table_create(flags);
return as;
}
/** Free Adress space */
void as_free(as_t *as)
{
ASSERT(as->refcount == 0);
/* TODO: free as_areas and other resources held by as */
/* TODO: free page table */
free(as);
}
/** Create address space area of common attributes.
*
* The created address space area is added to the target address space.
*
* @param as Target address space.
* @param flags Flags of the area memory.
* @param size Size of area.
* @param base Base address of area.
* @param attrs Attributes of the area.
*
* @return Address space area on success or NULL on failure.
*/
as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs)
{
ipl_t ipl;
as_area_t *a;
if (base % PAGE_SIZE)
return NULL;
if (!size)
return NULL;
/* Writeable executable areas are not supported. */
if ((flags & AS_AREA_EXEC) && (flags & AS_AREA_WRITE))
return NULL;
ipl = interrupts_disable();
spinlock_lock(&as->lock);
if (!check_area_conflicts(as, base, size, NULL)) {
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return NULL;
}
a = (as_area_t *) malloc(sizeof(as_area_t), 0);
spinlock_initialize(&a->lock, "as_area_lock");
a->flags = flags;
a->attributes = attrs;
a->pages = SIZE2FRAMES(size);
a->base = base;
btree_insert(&as->as_area_btree, base, (void *) a, NULL);
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return a;
}
/** Find address space area and change it.
*
* @param as Address space.
* @param address Virtual address belonging to the area to be changed. Must be page-aligned.
* @param size New size of the virtual memory block starting at address.
* @param flags Flags influencing the remap operation. Currently unused.
*
* @return Zero on success or a value from @ref errno.h otherwise.
*/
int as_area_resize(as_t *as, __address address, size_t size, int flags)
{
as_area_t *area;
ipl_t ipl;
size_t pages;
ipl = interrupts_disable();
spinlock_lock(&as->lock);
/*
* Locate the area.
*/
area = find_area_and_lock(as, address);
if (!area) {
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return ENOENT;
}
if (area->flags & AS_AREA_DEVICE) {
/*
* Remapping of address space areas associated
* with memory mapped devices is not supported.
*/
spinlock_unlock(&area->lock);
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return ENOTSUP;
}
pages = SIZE2FRAMES((address - area->base) + size);
if (!pages) {
/*
* Zero size address space areas are not allowed.
*/
spinlock_unlock(&area->lock);
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return EPERM;
}
if (pages < area->pages) {
int i;
/*
* Shrinking the area.
* No need to check for overlaps.
*/
for (i = pages; i < area->pages; i++) {
pte_t *pte;
/*
* Releasing physical memory.
* This depends on the fact that the memory was allocated using frame_alloc().
*/
page_table_lock(as, false);
pte = page_mapping_find(as, area->base + i*PAGE_SIZE);
if (pte && PTE_VALID(pte)) {
__address frame;
ASSERT(PTE_PRESENT(pte));
frame = PTE_GET_FRAME(pte);
page_mapping_remove(as, area->base + i*PAGE_SIZE);
page_table_unlock(as, false);
frame_free(ADDR2PFN(frame));
} else {
page_table_unlock(as, false);
}
}
/*
* Invalidate TLB's.
*/
tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
tlb_invalidate_pages(AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages);
tlb_shootdown_finalize();
} else {
/*
* Growing the area.
* Check for overlaps with other address space areas.
*/
if (!check_area_conflicts(as, address, pages * PAGE_SIZE, area)) {
spinlock_unlock(&area->lock);
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return EADDRNOTAVAIL;
}
}
area->pages = pages;
spinlock_unlock(&area->lock);
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return 0;
}
/** Destroy address space area.
*
* @param as Address space.
* @param address Address withing the area to be deleted.
*
* @return Zero on success or a value from @ref errno.h on failure.
*/
int as_area_destroy(as_t *as, __address address)
{
as_area_t *area;
__address base;
ipl_t ipl;
int i;
ipl = interrupts_disable();
spinlock_lock(&as->lock);
area = find_area_and_lock(as, address);
if (!area) {
spinlock_unlock(&as->lock);
interrupts_restore(ipl);
return ENOENT;
}
base = area->base;
for (i = 0; i < area->pages; i++) {
pte_t *pte;
/*
* Releasing physical memory.
* Areas mapping memory-mapped devices are treated differently than
* areas backing frame_alloc()'ed memory.
*/
page_table_lock(as, false);
pte = page_mapping_find(as, area->base + i*PAGE_SIZE);
if (pte && PTE_VALID(pte)) {
ASSERT(PTE_PRESENT(pte));
page_mapping_remove(as, area->base + i*PAGE_SIZE);
if (area->flags & AS_AREA_DEVICE) {
__address frame;
frame = PTE_GET_FRAME(pte);
frame_free(ADDR2PFN(frame));
}
page_table_unlock(as, false);
} else {
page_table_unlock(as, false);
}
}
/*
* Invalidate TLB's.
*/
tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages);
tlb_invalidate_pages(AS->asid, area->base, area->pages);
tlb_shootdown_finalize();
area->attributes |= AS_AREA_ATTR_PARTIAL;
spinlock_unlock(&area->lock);
/*
* Remove the empty area from address space.
*/
btree_remove(&AS->as_area_btree, base, NULL);
free(area);
spinlock_unlock(&AS->lock);
interrupts_restore(ipl);
return 0;
}
/** Steal address space area from another task.
*
* Address space area is stolen from another task
* Moreover, any existing mapping
* is copied as well, providing thus a mechanism
* for sharing group of pages. The source address
* space area and any associated mapping is preserved.
*
* @param src_task Pointer of source task
* @param src_base Base address of the source address space area.
* @param acc_size Expected size of the source area
* @param dst_base Target base address
*
* @return Zero on success or ENOENT if there is no such task or
* if there is no such address space area,
* EPERM if there was a problem in accepting the area or
* ENOMEM if there was a problem in allocating destination
* address space area.
*/
int as_area_steal(task_t *src_task, __address src_base, size_t acc_size,
__address dst_base)
{
ipl_t ipl;
count_t i;
as_t *src_as;
int src_flags;
size_t src_size;
as_area_t *src_area, *dst_area;
ipl = interrupts_disable();
spinlock_lock(&src_task->lock);
src_as = src_task->as;
spinlock_lock(&src_as->lock);
src_area = find_area_and_lock(src_as, src_base);
if (!src_area) {
/*
* Could not find the source address space area.
*/
spinlock_unlock(&src_task->lock);
spinlock_unlock(&src_as->lock);
interrupts_restore(ipl);
return ENOENT;
}
src_size = src_area->pages * PAGE_SIZE;
src_flags = src_area->flags;
spinlock_unlock(&src_area->lock);
spinlock_unlock(&src_as->lock);
if (src_size != acc_size) {
spinlock_unlock(&src_task->lock);
interrupts_restore(ipl);
return EPERM;
}
/*
* Create copy of the source address space area.
* The destination area is created with AS_AREA_ATTR_PARTIAL
* attribute set which prevents race condition with
* preliminary as_page_fault() calls.
*/
dst_area = as_area_create(AS, src_flags, src_size, dst_base, AS_AREA_ATTR_PARTIAL);
if (!dst_area) {
/*
* Destination address space area could not be created.
*/
spinlock_unlock(&src_task->lock);
interrupts_restore(ipl);
return ENOMEM;
}
spinlock_unlock(&src_task->lock);
/*
* Avoid deadlock by first locking the address space with lower address.
*/
if (AS < src_as) {
spinlock_lock(&AS->lock);
spinlock_lock(&src_as->lock);
} else {
spinlock_lock(&AS->lock);
spinlock_lock(&src_as->lock);
}
for (i = 0; i < SIZE2FRAMES(src_size); i++) {
pte_t *pte;
__address frame;
page_table_lock(src_as, false);
pte = page_mapping_find(src_as, src_base + i*PAGE_SIZE);
if (pte && PTE_VALID(pte)) {
ASSERT(PTE_PRESENT(pte));
frame = PTE_GET_FRAME(pte);
if (!(src_flags & AS_AREA_DEVICE))
frame_reference_add(ADDR2PFN(frame));
page_table_unlock(src_as, false);
} else {
page_table_unlock(src_as, false);
continue;
}
page_table_lock(AS, false);
page_mapping_insert(AS, dst_base + i*PAGE_SIZE, frame, area_flags_to_page_flags(src_flags));
page_table_unlock(AS, false);
}
/*
* Now the destination address space area has been
* fully initialized. Clear the AS_AREA_ATTR_PARTIAL
* attribute.
*/
spinlock_lock(&dst_area->lock);
dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL;
spinlock_unlock(&dst_area->lock);
spinlock_unlock(&AS->lock);
spinlock_unlock(&src_as->lock);
interrupts_restore(ipl);
return 0;
}
/** Initialize mapping for one page of address space.
*
* This functions maps 'page' to 'frame' according
* to attributes of the address space area to
* wich 'page' belongs.
*
* @param as Target address space.
* @param page Virtual page within the area.
* @param frame Physical frame to which page will be mapped.
*/
void as_set_mapping(as_t *as, __address page, __address frame)
{
as_area_t *area;
ipl_t ipl;
ipl = interrupts_disable();
page_table_lock(as, true);
area = find_area_and_lock(as, page);
if (!area) {
panic("page not part of any as_area\n");
}
page_mapping_insert(as, page, frame, get_area_flags(area));
spinlock_unlock(&area->lock);
page_table_unlock(as, true);
interrupts_restore(ipl);
}
/** Handle page fault within the current address space.
*
* This is the high-level page fault handler.
* Interrupts are assumed disabled.
*
* @param page Faulting page.
* @param istate Pointer to interrupted state.
*
* @return 0 on page fault, 1 on success or 2 if the fault was caused by copy_to_uspace() or copy_from_uspace().
*/
int as_page_fault(__address page, istate_t *istate)
{
pte_t *pte;
as_area_t *area;
__address frame;
ASSERT(AS);
spinlock_lock(&AS->lock);
area = find_area_and_lock(AS, page);
if (!area) {
/*
* No area contained mapping for 'page'.
* Signal page fault to low-level handler.
*/
spinlock_unlock(&AS->lock);
goto page_fault;
}
if (area->attributes & AS_AREA_ATTR_PARTIAL) {
/*
* The address space area is not fully initialized.
* Avoid possible race by returning error.
*/
spinlock_unlock(&area->lock);
spinlock_unlock(&AS->lock);
goto page_fault;
}
ASSERT(!(area->flags & AS_AREA_DEVICE));
page_table_lock(AS, false);
/*
* To avoid race condition between two page faults
* on the same address, we need to make sure
* the mapping has not been already inserted.
*/
if ((pte = page_mapping_find(AS, page))) {
if (PTE_PRESENT(pte)) {
page_table_unlock(AS, false);
spinlock_unlock(&area->lock);
spinlock_unlock(&AS->lock);
return 1;
}
}
/*
* In general, there can be several reasons that
* can have caused this fault.
*
* - non-existent mapping: the area is a scratch
* area (e.g. stack) and so far has not been
* allocated a frame for the faulting page
*
* - non-present mapping: another possibility,
* currently not implemented, would be frame
* reuse; when this becomes a possibility,
* do not forget to distinguish between
* the different causes
*/
frame = PFN2ADDR(frame_alloc(ONE_FRAME, 0));
memsetb(PA2KA(frame), FRAME_SIZE, 0);
/*
* Map 'page' to 'frame'.
* Note that TLB shootdown is not attempted as only new information is being
* inserted into page tables.
*/
page_mapping_insert(AS, page, frame, get_area_flags(area));
page_table_unlock(AS, false);
spinlock_unlock(&area->lock);
spinlock_unlock(&AS->lock);
return AS_PF_OK;
page_fault:
if (!THREAD)
return AS_PF_FAULT;
if (THREAD->in_copy_from_uspace) {
THREAD->in_copy_from_uspace = false;
istate_set_retaddr(istate, (__address) &memcpy_from_uspace_failover_address);
} else if (THREAD->in_copy_to_uspace) {
THREAD->in_copy_to_uspace = false;
istate_set_retaddr(istate, (__address) &memcpy_to_uspace_failover_address);
} else {
return AS_PF_FAULT;
}
return AS_PF_DEFER;
}
/** Switch address spaces.
*
* @param old Old address space or NULL.
* @param new New address space.
*/
void as_switch(as_t *old, as_t *new)
{
ipl_t ipl;
bool needs_asid = false;
ipl = interrupts_disable();
spinlock_lock(&as_lock);
/*
* First, take care of the old address space.
*/
if (old) {
spinlock_lock(&old->lock);
ASSERT(old->refcount);
if((--old->refcount == 0) && (old != AS_KERNEL)) {
/*
* The old address space is no longer active on
* any processor. It can be appended to the
* list of inactive address spaces with assigned
* ASID.
*/
ASSERT(old->asid != ASID_INVALID);
list_append(&old->inactive_as_with_asid_link, &inactive_as_with_asid_head);
}
spinlock_unlock(&old->lock);
}
/*
* Second, prepare the new address space.
*/
spinlock_lock(&new->lock);
if ((new->refcount++ == 0) && (new != AS_KERNEL)) {
if (new->asid != ASID_INVALID)
list_remove(&new->inactive_as_with_asid_link);
else
needs_asid = true; /* defer call to asid_get() until new->lock is released */
}
SET_PTL0_ADDRESS(new->page_table);
spinlock_unlock(&new->lock);
if (needs_asid) {
/*
* Allocation of new ASID was deferred
* until now in order to avoid deadlock.
*/
asid_t asid;
asid = asid_get();
spinlock_lock(&new->lock);
new->asid = asid;
spinlock_unlock(&new->lock);
}
spinlock_unlock(&as_lock);
interrupts_restore(ipl);
/*
* Perform architecture-specific steps.
* (e.g. write ASID to hardware register etc.)
*/
as_install_arch(new);
AS = new;
}
/** Convert address space area flags to page flags.
*
* @param aflags Flags of some address space area.
*
* @return Flags to be passed to page_mapping_insert().
*/
int area_flags_to_page_flags(int aflags)
{
int flags;
flags = PAGE_USER | PAGE_PRESENT;
if (aflags & AS_AREA_READ)
flags |= PAGE_READ;
if (aflags & AS_AREA_WRITE)
flags |= PAGE_WRITE;
if (aflags & AS_AREA_EXEC)
flags |= PAGE_EXEC;
if (!(aflags & AS_AREA_DEVICE))
flags |= PAGE_CACHEABLE;
return flags;
}
/** Compute flags for virtual address translation subsytem.
*
* The address space area must be locked.
* Interrupts must be disabled.
*
* @param a Address space area.
*
* @return Flags to be used in page_mapping_insert().
*/
int get_area_flags(as_area_t *a)
{
return area_flags_to_page_flags(a->flags);
}
/** Create page table.
*
* Depending on architecture, create either address space
* private or global page table.
*
* @param flags Flags saying whether the page table is for kernel address space.
*
* @return First entry of the page table.
*/
pte_t *page_table_create(int flags)
{
ASSERT(as_operations);
ASSERT(as_operations->page_table_create);
return as_operations->page_table_create(flags);
}
/** Lock page table.
*
* This function should be called before any page_mapping_insert(),
* page_mapping_remove() and page_mapping_find().
*
* Locking order is such that address space areas must be locked
* prior to this call. Address space can be locked prior to this
* call in which case the lock argument is false.
*
* @param as Address space.
* @param lock If false, do not attempt to lock as->lock.
*/
void page_table_lock(as_t *as, bool lock)
{
ASSERT(as_operations);
ASSERT(as_operations->page_table_lock);
as_operations->page_table_lock(as, lock);
}
/** Unlock page table.
*
* @param as Address space.
* @param unlock If false, do not attempt to unlock as->lock.
*/
void page_table_unlock(as_t *as, bool unlock)
{
ASSERT(as_operations);
ASSERT(as_operations->page_table_unlock);
as_operations->page_table_unlock(as, unlock);
}
/** Find address space area and lock it.
*
* The address space must be locked and interrupts must be disabled.
*
* @param as Address space.
* @param va Virtual address.
*
* @return Locked address space area containing va on success or NULL on failure.
*/
as_area_t *find_area_and_lock(as_t *as, __address va)
{
as_area_t *a;
btree_node_t *leaf, *lnode;
int i;
a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf);
if (a) {
/* va is the base address of an address space area */
spinlock_lock(&a->lock);
return a;
}
/*
* Search the leaf node and the righmost record of its left neighbour
* to find out whether this is a miss or va belongs to an address
* space area found there.
*/
/* First, search the leaf node itself. */
for (i = 0; i < leaf->keys; i++) {
a = (as_area_t *) leaf->value[i];
spinlock_lock(&a->lock);
if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) {
return a;
}
spinlock_unlock(&a->lock);
}
/*
* Second, locate the left neighbour and test its last record.
* Because of its position in the B+tree, it must have base < va.
*/
if ((lnode = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
a = (as_area_t *) lnode->value[lnode->keys - 1];
spinlock_lock(&a->lock);
if (va < a->base + a->pages * PAGE_SIZE) {
return a;
}
spinlock_unlock(&a->lock);
}
return NULL;
}
/** Check area conflicts with other areas.
*
* The address space must be locked and interrupts must be disabled.
*
* @param as Address space.
* @param va Starting virtual address of the area being tested.
* @param size Size of the area being tested.
* @param avoid_area Do not touch this area.
*
* @return True if there is no conflict, false otherwise.
*/
bool check_area_conflicts(as_t *as, __address va, size_t size, as_area_t *avoid_area)
{
as_area_t *a;
btree_node_t *leaf, *node;
int i;
/*
* We don't want any area to have conflicts with NULL page.
*/
if (overlaps(va, size, NULL, PAGE_SIZE))
return false;
/*
* The leaf node is found in O(log n), where n is proportional to
* the number of address space areas belonging to as.
* The check for conflicts is then attempted on the rightmost
* record in the left neighbour, the leftmost record in the right
* neighbour and all records in the leaf node itself.
*/
if ((a = (as_area_t *) btree_search(&as->as_area_btree, va, &leaf))) {
if (a != avoid_area)
return false;
}
/* First, check the two border cases. */
if ((node = btree_leaf_node_left_neighbour(&as->as_area_btree, leaf))) {
a = (as_area_t *) node->value[node->keys - 1];
spinlock_lock(&a->lock);
if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
spinlock_unlock(&a->lock);
return false;
}
spinlock_unlock(&a->lock);
}
if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) {
a = (as_area_t *) node->value[0];
spinlock_lock(&a->lock);
if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
spinlock_unlock(&a->lock);
return false;
}
spinlock_unlock(&a->lock);
}
/* Second, check the leaf node. */
for (i = 0; i < leaf->keys; i++) {
a = (as_area_t *) leaf->value[i];
if (a == avoid_area)
continue;
spinlock_lock(&a->lock);
if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) {
spinlock_unlock(&a->lock);
return false;
}
spinlock_unlock(&a->lock);
}
/*
* So far, the area does not conflict with other areas.
* Check if it doesn't conflict with kernel address space.
*/
if (!KERNEL_ADDRESS_SPACE_SHADOWED) {
return !overlaps(va, size,
KERNEL_ADDRESS_SPACE_START, KERNEL_ADDRESS_SPACE_END-KERNEL_ADDRESS_SPACE_START);
}
return true;
}
/** Return size of address space of current task pointed to by base */
size_t as_get_size(__address base)
{
ipl_t ipl;
as_area_t *src_area;
size_t size;
ipl = interrupts_disable();
src_area = find_area_and_lock(AS, base);
if (src_area){
size = src_area->pages * PAGE_SIZE;
spinlock_unlock(&src_area->lock);
} else {
size = 0;
}
interrupts_restore(ipl);
return size;
}
/*
* Address space related syscalls.
*/
/** Wrapper for as_area_create(). */
__native sys_as_area_create(__address address, size_t size, int flags)
{
if (as_area_create(AS, flags, size, address, AS_AREA_ATTR_NONE))
return (__native) address;
else
return (__native) -1;
}
/** Wrapper for as_area_resize. */
__native sys_as_area_resize(__address address, size_t size, int flags)
{
return (__native) as_area_resize(AS, address, size, 0);
}
/** Wrapper for as_area_destroy. */
__native sys_as_area_destroy(__address address)
{
return (__native) as_area_destroy(AS, address);
}

/tags/0.1.1/kernel/generic/src/mm/tlb.c
0,0 → 1,182
/*
* Copyright (C) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file tlb.c
* @brief Generic TLB shootdown algorithm.
*
* The algorithm implemented here is based on the CMU TLB shootdown
* algorithm and is further simplified (e.g. all CPUs receive all TLB
* shootdown messages).
*/
#include <mm/tlb.h>
#include <mm/asid.h>
#include <arch/mm/tlb.h>
#include <smp/ipi.h>
#include <synch/spinlock.h>
#include <typedefs.h>
#include <atomic.h>
#include <arch/interrupt.h>
#include <config.h>
#include <arch.h>
#include <panic.h>
#include <debug.h>
/**
* This lock is used for synchronisation between sender and
* recipients of TLB shootdown message. It must be acquired
* before CPU structure lock.
*/
SPINLOCK_INITIALIZE(tlblock);
void tlb_init(void)
{
tlb_arch_init();
}
#ifdef CONFIG_SMP
/** Send TLB shootdown message.
*
* This function attempts to deliver TLB shootdown message
* to all other processors.
*
* This function must be called with interrupts disabled.
*
* @param type Type describing scope of shootdown.
* @param asid Address space, if required by type.
* @param page Virtual page address, if required by type.
* @param count Number of pages, if required by type.
*/
void tlb_shootdown_start(tlb_invalidate_type_t type, asid_t asid, __address page, count_t count)
{
int i;
CPU->tlb_active = 0;
spinlock_lock(&tlblock);
for (i = 0; i < config.cpu_count; i++) {
cpu_t *cpu;
if (i == CPU->id)
continue;
cpu = &cpus[i];
spinlock_lock(&cpu->lock);
if (cpu->tlb_messages_count == TLB_MESSAGE_QUEUE_LEN) {
/*
* The message queue is full.
* Erase the queue and store one TLB_INVL_ALL message.
*/
cpu->tlb_messages_count = 1;
cpu->tlb_messages[0].type = TLB_INVL_ALL;
cpu->tlb_messages[0].asid = ASID_INVALID;
cpu->tlb_messages[0].page = 0;
cpu->tlb_messages[0].count = 0;
} else {
/*
* Enqueue the message.
*/
cpu->tlb_messages[cpu->tlb_messages_count].type = type;
cpu->tlb_messages[cpu->tlb_messages_count].asid = asid;
cpu->tlb_messages[cpu->tlb_messages_count].page = page;
cpu->tlb_messages[cpu->tlb_messages_count].count = count;
cpu->tlb_messages_count++;
}
spinlock_unlock(&cpu->lock);
}
tlb_shootdown_ipi_send();
busy_wait:
for (i = 0; i < config.cpu_count; i++)
if (cpus[i].tlb_active)
goto busy_wait;
}
/** Finish TLB shootdown sequence. */
void tlb_shootdown_finalize(void)
{
spinlock_unlock(&tlblock);
CPU->tlb_active = 1;
}
void tlb_shootdown_ipi_send(void)
{
ipi_broadcast(VECTOR_TLB_SHOOTDOWN_IPI);
}
/** Receive TLB shootdown message. */
void tlb_shootdown_ipi_recv(void)
{
tlb_invalidate_type_t type;
asid_t asid;
__address page;
count_t count;
int i;
ASSERT(CPU);
CPU->tlb_active = 0;
spinlock_lock(&tlblock);
spinlock_unlock(&tlblock);
spinlock_lock(&CPU->lock);
ASSERT(CPU->tlb_messages_count <= TLB_MESSAGE_QUEUE_LEN);
for (i = 0; i < CPU->tlb_messages_count; CPU->tlb_messages_count--) {
type = CPU->tlb_messages[i].type;
asid = CPU->tlb_messages[i].asid;
page = CPU->tlb_messages[i].page;
count = CPU->tlb_messages[i].count;
switch (type) {
case TLB_INVL_ALL:
tlb_invalidate_all();
break;
case TLB_INVL_ASID:
tlb_invalidate_asid(asid);
break;
case TLB_INVL_PAGES:
ASSERT(count);
tlb_invalidate_pages(asid, page, count);
break;
default:
panic("unknown type (%d)\n", type);
break;
}
if (type == TLB_INVL_ALL)
break;
}
spinlock_unlock(&CPU->lock);
CPU->tlb_active = 1;
}
#endif /* CONFIG_SMP */

/tags/0.1.1/kernel/generic/src/mm/slab.c
0,0 → 1,900
/*
* Copyright (C) 2006 Ondrej Palkovsky
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file slab.c
* @brief Slab allocator.
*
* The slab allocator is closely modelled after OpenSolaris slab allocator.
* @see http://www.usenix.org/events/usenix01/full_papers/bonwick/bonwick_html/
*
* with the following exceptions:
* @li empty slabs are deallocated immediately
* (in Linux they are kept in linked list, in Solaris ???)
* @li empty magazines are deallocated when not needed
* (in Solaris they are held in linked list in slab cache)
*
* Following features are not currently supported but would be easy to do:
* @li cache coloring
* @li dynamic magazine growing (different magazine sizes are already
* supported, but we would need to adjust allocation strategy)
*
* The slab allocator supports per-CPU caches ('magazines') to facilitate
* good SMP scaling.
*
* When a new object is being allocated, it is first checked, if it is
* available in CPU-bound magazine. If it is not found there, it is
* allocated from CPU-shared slab - if partial full is found, it is used,
* otherwise a new one is allocated.
*
* When an object is being deallocated, it is put to CPU-bound magazine.
* If there is no such magazine, new one is allocated (if it fails,
* the object is deallocated into slab). If the magazine is full, it is
* put into cpu-shared list of magazines and new one is allocated.
*
* The CPU-bound magazine is actually a pair of magazine to avoid
* thrashing when somebody is allocating/deallocating 1 item at the magazine
* size boundary. LIFO order is enforced, which should avoid fragmentation
* as much as possible.
*
* Every cache contains list of full slabs and list of partialy full slabs.
* Empty slabs are immediately freed (thrashing will be avoided because
* of magazines).
*
* The slab information structure is kept inside the data area, if possible.
* The cache can be marked that it should not use magazines. This is used
* only for slab related caches to avoid deadlocks and infinite recursion
* (the slab allocator uses itself for allocating all it's control structures).
*
* The slab allocator allocates lot of space and does not free it. When
* frame allocator fails to allocate the frame, it calls slab_reclaim().
* It tries 'light reclaim' first, then brutal reclaim. The light reclaim
* releases slabs from cpu-shared magazine-list, until at least 1 slab
* is deallocated in each cache (this algorithm should probably change).
* The brutal reclaim removes all cached objects, even from CPU-bound
* magazines.
*
* TODO:@n
* For better CPU-scaling the magazine allocation strategy should
* be extended. Currently, if the cache does not have magazine, it asks
* for non-cpu cached magazine cache to provide one. It might be feasible
* to add cpu-cached magazine cache (which would allocate it's magazines
* from non-cpu-cached mag. cache). This would provide a nice per-cpu
* buffer. The other possibility is to use the per-cache
* 'empty-magazine-list', which decreases competing for 1 per-system
* magazine cache.
*
* @li it might be good to add granularity of locks even to slab level,
* we could then try_spinlock over all partial slabs and thus improve
* scalability even on slab level
*/
#include <synch/spinlock.h>
#include <mm/slab.h>
#include <adt/list.h>
#include <memstr.h>
#include <align.h>
#include <mm/frame.h>
#include <config.h>
#include <print.h>
#include <arch.h>
#include <panic.h>
#include <debug.h>
#include <bitops.h>
SPINLOCK_INITIALIZE(slab_cache_lock);
static LIST_INITIALIZE(slab_cache_list);
/** Magazine cache */
static slab_cache_t mag_cache;
/** Cache for cache descriptors */
static slab_cache_t slab_cache_cache;
/** Cache for external slab descriptors
* This time we want per-cpu cache, so do not make it static
* - using slab for internal slab structures will not deadlock,
* as all slab structures are 'small' - control structures of
* their caches do not require further allocation
*/
static slab_cache_t *slab_extern_cache;
/** Caches for malloc */
static slab_cache_t *malloc_caches[SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1];
char *malloc_names[] = {
"malloc-16","malloc-32","malloc-64","malloc-128",
"malloc-256","malloc-512","malloc-1K","malloc-2K",
"malloc-4K","malloc-8K","malloc-16K","malloc-32K",
"malloc-64K","malloc-128K"
};
/** Slab descriptor */
typedef struct {
slab_cache_t *cache; /**< Pointer to parent cache */
link_t link; /* List of full/partial slabs */
void *start; /**< Start address of first available item */
count_t available; /**< Count of available items in this slab */
index_t nextavail; /**< The index of next available item */
}slab_t;
#ifdef CONFIG_DEBUG
static int _slab_initialized = 0;
#endif
/**************************************/
/* Slab allocation functions */
/**
* Allocate frames for slab space and initialize
*
*/
static slab_t * slab_space_alloc(slab_cache_t *cache, int flags)
{
void *data;
slab_t *slab;
size_t fsize;
int i;
int status;
pfn_t pfn;
int zone=0;
pfn = frame_alloc_rc_zone(cache->order, FRAME_KA | flags, &status, &zone);
data = (void *) PA2KA(PFN2ADDR(pfn));
if (status != FRAME_OK) {
return NULL;
}
if (! (cache->flags & SLAB_CACHE_SLINSIDE)) {
slab = slab_alloc(slab_extern_cache, flags);
if (!slab) {
frame_free(ADDR2PFN(KA2PA(data)));
return NULL;
}
} else {
fsize = (PAGE_SIZE << cache->order);
slab = data + fsize - sizeof(*slab);
}
/* Fill in slab structures */
for (i=0; i < (1 << cache->order); i++)
frame_set_parent(pfn+i, slab, zone);
slab->start = data;
slab->available = cache->objects;
slab->nextavail = 0;
slab->cache = cache;
for (i=0; i<cache->objects;i++)
*((int *) (slab->start + i*cache->size)) = i+1;
atomic_inc(&cache->allocated_slabs);
return slab;
}
/**
* Deallocate space associated with slab
*
* @return number of freed frames
*/
static count_t slab_space_free(slab_cache_t *cache, slab_t *slab)
{
frame_free(ADDR2PFN(KA2PA(slab->start)));
if (! (cache->flags & SLAB_CACHE_SLINSIDE))
slab_free(slab_extern_cache, slab);
atomic_dec(&cache->allocated_slabs);
return 1 << cache->order;
}
/** Map object to slab structure */
static slab_t * obj2slab(void *obj)
{
return (slab_t *)frame_get_parent(ADDR2PFN(KA2PA(obj)), 0);
}
/**************************************/
/* Slab functions */
/**
* Return object to slab and call a destructor
*
* @param slab If the caller knows directly slab of the object, otherwise NULL
*
* @return Number of freed pages
*/
static count_t slab_obj_destroy(slab_cache_t *cache, void *obj,
slab_t *slab)
{
int freed = 0;
if (!slab)
slab = obj2slab(obj);
ASSERT(slab->cache == cache);
if (cache->destructor)
freed = cache->destructor(obj);
spinlock_lock(&cache->slablock);
ASSERT(slab->available < cache->objects);
*((int *)obj) = slab->nextavail;
slab->nextavail = (obj - slab->start)/cache->size;
slab->available++;
/* Move it to correct list */
if (slab->available == cache->objects) {
/* Free associated memory */
list_remove(&slab->link);
spinlock_unlock(&cache->slablock);
return freed + slab_space_free(cache, slab);
} else if (slab->available == 1) {
/* It was in full, move to partial */
list_remove(&slab->link);
list_prepend(&slab->link, &cache->partial_slabs);
}
spinlock_unlock(&cache->slablock);
return freed;
}
/**
* Take new object from slab or create new if needed
*
* @return Object address or null
*/
static void * slab_obj_create(slab_cache_t *cache, int flags)
{
slab_t *slab;
void *obj;
spinlock_lock(&cache->slablock);
if (list_empty(&cache->partial_slabs)) {
/* Allow recursion and reclaiming
* - this should work, as the slab control structures
* are small and do not need to allocate with anything
* other than frame_alloc when they are allocating,
* that's why we should get recursion at most 1-level deep
*/
spinlock_unlock(&cache->slablock);
slab = slab_space_alloc(cache, flags);
if (!slab)
return NULL;
spinlock_lock(&cache->slablock);
} else {
slab = list_get_instance(cache->partial_slabs.next,
slab_t,
link);
list_remove(&slab->link);
}
obj = slab->start + slab->nextavail * cache->size;
slab->nextavail = *((int *)obj);
slab->available--;
if (! slab->available)
list_prepend(&slab->link, &cache->full_slabs);
else
list_prepend(&slab->link, &cache->partial_slabs);
spinlock_unlock(&cache->slablock);
if (cache->constructor && cache->constructor(obj, flags)) {
/* Bad, bad, construction failed */
slab_obj_destroy(cache, obj, slab);
return NULL;
}
return obj;
}
/**************************************/
/* CPU-Cache slab functions */
/**
* Finds a full magazine in cache, takes it from list
* and returns it
*
* @param first If true, return first, else last mag
*/
static slab_magazine_t * get_mag_from_cache(slab_cache_t *cache,
int first)
{
slab_magazine_t *mag = NULL;
link_t *cur;
spinlock_lock(&cache->maglock);
if (!list_empty(&cache->magazines)) {
if (first)
cur = cache->magazines.next;
else
cur = cache->magazines.prev;
mag = list_get_instance(cur, slab_magazine_t, link);
list_remove(&mag->link);
atomic_dec(&cache->magazine_counter);
}
spinlock_unlock(&cache->maglock);
return mag;
}
/** Prepend magazine to magazine list in cache */
static void put_mag_to_cache(slab_cache_t *cache, slab_magazine_t *mag)
{
spinlock_lock(&cache->maglock);
list_prepend(&mag->link, &cache->magazines);
atomic_inc(&cache->magazine_counter);
spinlock_unlock(&cache->maglock);
}
/**
* Free all objects in magazine and free memory associated with magazine
*
* @return Number of freed pages
*/
static count_t magazine_destroy(slab_cache_t *cache,
slab_magazine_t *mag)
{
int i;
count_t frames = 0;
for (i=0;i < mag->busy; i++) {
frames += slab_obj_destroy(cache, mag->objs[i], NULL);
atomic_dec(&cache->cached_objs);
}
slab_free(&mag_cache, mag);
return frames;
}
/**
* Find full magazine, set it as current and return it
*
* Assume cpu_magazine lock is held
*/
static slab_magazine_t * get_full_current_mag(slab_cache_t *cache)
{
slab_magazine_t *cmag, *lastmag, *newmag;
cmag = cache->mag_cache[CPU->id].current;
lastmag = cache->mag_cache[CPU->id].last;
if (cmag) { /* First try local CPU magazines */
if (cmag->busy)
return cmag;
if (lastmag && lastmag->busy) {
cache->mag_cache[CPU->id].current = lastmag;
cache->mag_cache[CPU->id].last = cmag;
return lastmag;
}
}
/* Local magazines are empty, import one from magazine list */
newmag = get_mag_from_cache(cache, 1);
if (!newmag)
return NULL;
if (lastmag)
magazine_destroy(cache, lastmag);
cache->mag_cache[CPU->id].last = cmag;
cache->mag_cache[CPU->id].current = newmag;
return newmag;
}
/**
* Try to find object in CPU-cache magazines
*
* @return Pointer to object or NULL if not available
*/
static void * magazine_obj_get(slab_cache_t *cache)
{
slab_magazine_t *mag;
void *obj;
if (!CPU)
return NULL;
spinlock_lock(&cache->mag_cache[CPU->id].lock);
mag = get_full_current_mag(cache);
if (!mag) {
spinlock_unlock(&cache->mag_cache[CPU->id].lock);
return NULL;
}
obj = mag->objs[--mag->busy];
spinlock_unlock(&cache->mag_cache[CPU->id].lock);
atomic_dec(&cache->cached_objs);
return obj;
}
/**
* Assure that the current magazine is empty, return pointer to it, or NULL if
* no empty magazine is available and cannot be allocated
*
* Assume mag_cache[CPU->id].lock is held
*
* We have 2 magazines bound to processor.
* First try the current.
* If full, try the last.
* If full, put to magazines list.
* allocate new, exchange last & current
*
*/
static slab_magazine_t * make_empty_current_mag(slab_cache_t *cache)
{
slab_magazine_t *cmag,*lastmag,*newmag;
cmag = cache->mag_cache[CPU->id].current;
lastmag = cache->mag_cache[CPU->id].last;
if (cmag) {
if (cmag->busy < cmag->size)
return cmag;
if (lastmag && lastmag->busy < lastmag->size) {
cache->mag_cache[CPU->id].last = cmag;
cache->mag_cache[CPU->id].current = lastmag;
return lastmag;
}
}
/* current | last are full | nonexistent, allocate new */
/* We do not want to sleep just because of caching */
/* Especially we do not want reclaiming to start, as
* this would deadlock */
newmag = slab_alloc(&mag_cache, FRAME_ATOMIC | FRAME_NO_RECLAIM);
if (!newmag)
return NULL;
newmag->size = SLAB_MAG_SIZE;
newmag->busy = 0;
/* Flush last to magazine list */
if (lastmag)
put_mag_to_cache(cache, lastmag);
/* Move current as last, save new as current */
cache->mag_cache[CPU->id].last = cmag;
cache->mag_cache[CPU->id].current = newmag;
return newmag;
}
/**
* Put object into CPU-cache magazine
*
* @return 0 - success, -1 - could not get memory
*/
static int magazine_obj_put(slab_cache_t *cache, void *obj)
{
slab_magazine_t *mag;
if (!CPU)
return -1;
spinlock_lock(&cache->mag_cache[CPU->id].lock);
mag = make_empty_current_mag(cache);
if (!mag) {
spinlock_unlock(&cache->mag_cache[CPU->id].lock);
return -1;
}
mag->objs[mag->busy++] = obj;
spinlock_unlock(&cache->mag_cache[CPU->id].lock);
atomic_inc(&cache->cached_objs);
return 0;
}
/**************************************/
/* Slab cache functions */
/** Return number of objects that fit in certain cache size */
static int comp_objects(slab_cache_t *cache)
{
if (cache->flags & SLAB_CACHE_SLINSIDE)
return ((PAGE_SIZE << cache->order) - sizeof(slab_t)) / cache->size;
else
return (PAGE_SIZE << cache->order) / cache->size;
}
/** Return wasted space in slab */
static int badness(slab_cache_t *cache)
{
int objects;
int ssize;
objects = comp_objects(cache);
ssize = PAGE_SIZE << cache->order;
if (cache->flags & SLAB_CACHE_SLINSIDE)
ssize -= sizeof(slab_t);
return ssize - objects*cache->size;
}
/**
* Initialize mag_cache structure in slab cache
*/
static void make_magcache(slab_cache_t *cache)
{
int i;
ASSERT(_slab_initialized >= 2);
cache->mag_cache = malloc(sizeof(slab_mag_cache_t)*config.cpu_count,0);
for (i=0; i < config.cpu_count; i++) {
memsetb((__address)&cache->mag_cache[i],
sizeof(cache->mag_cache[i]), 0);
spinlock_initialize(&cache->mag_cache[i].lock,
"slab_maglock_cpu");
}
}
/** Initialize allocated memory as a slab cache */
static void
_slab_cache_create(slab_cache_t *cache,
char *name,
size_t size,
size_t align,
int (*constructor)(void *obj, int kmflag),
int (*destructor)(void *obj),
int flags)
{
int pages;
ipl_t ipl;
memsetb((__address)cache, sizeof(*cache), 0);
cache->name = name;
if (align < sizeof(__native))
align = sizeof(__native);
size = ALIGN_UP(size, align);
cache->size = size;
cache->constructor = constructor;
cache->destructor = destructor;
cache->flags = flags;
list_initialize(&cache->full_slabs);
list_initialize(&cache->partial_slabs);
list_initialize(&cache->magazines);
spinlock_initialize(&cache->slablock, "slab_lock");
spinlock_initialize(&cache->maglock, "slab_maglock");
if (! (cache->flags & SLAB_CACHE_NOMAGAZINE))
make_magcache(cache);
/* Compute slab sizes, object counts in slabs etc. */
if (cache->size < SLAB_INSIDE_SIZE)
cache->flags |= SLAB_CACHE_SLINSIDE;
/* Minimum slab order */
pages = ((cache->size-1) >> PAGE_WIDTH) + 1;
cache->order = fnzb(pages);
while (badness(cache) > SLAB_MAX_BADNESS(cache)) {
cache->order += 1;
}
cache->objects = comp_objects(cache);
/* If info fits in, put it inside */
if (badness(cache) > sizeof(slab_t))
cache->flags |= SLAB_CACHE_SLINSIDE;
/* Add cache to cache list */
ipl = interrupts_disable();
spinlock_lock(&slab_cache_lock);
list_append(&cache->link, &slab_cache_list);
spinlock_unlock(&slab_cache_lock);
interrupts_restore(ipl);
}
/** Create slab cache */
slab_cache_t * slab_cache_create(char *name,
size_t size,
size_t align,
int (*constructor)(void *obj, int kmflag),
int (*destructor)(void *obj),
int flags)
{
slab_cache_t *cache;
cache = slab_alloc(&slab_cache_cache, 0);
_slab_cache_create(cache, name, size, align, constructor, destructor,
flags);
return cache;
}
/**
* Reclaim space occupied by objects that are already free
*
* @param flags If contains SLAB_RECLAIM_ALL, do aggressive freeing
* @return Number of freed pages
*/
static count_t _slab_reclaim(slab_cache_t *cache, int flags)
{
int i;
slab_magazine_t *mag;
count_t frames = 0;
int magcount;
if (cache->flags & SLAB_CACHE_NOMAGAZINE)
return 0; /* Nothing to do */
/* We count up to original magazine count to avoid
* endless loop
*/
magcount = atomic_get(&cache->magazine_counter);
while (magcount-- && (mag=get_mag_from_cache(cache,0))) {
frames += magazine_destroy(cache,mag);
if (!(flags & SLAB_RECLAIM_ALL) && frames)
break;
}
if (flags & SLAB_RECLAIM_ALL) {
/* Free cpu-bound magazines */
/* Destroy CPU magazines */
for (i=0; i<config.cpu_count; i++) {
spinlock_lock(&cache->mag_cache[i].lock);
mag = cache->mag_cache[i].current;
if (mag)
frames += magazine_destroy(cache, mag);
cache->mag_cache[i].current = NULL;
mag = cache->mag_cache[i].last;
if (mag)
frames += magazine_destroy(cache, mag);
cache->mag_cache[i].last = NULL;
spinlock_unlock(&cache->mag_cache[i].lock);
}
}
return frames;
}
/** Check that there are no slabs and remove cache from system */
void slab_cache_destroy(slab_cache_t *cache)
{
ipl_t ipl;
/* First remove cache from link, so that we don't need
* to disable interrupts later
*/
ipl = interrupts_disable();
spinlock_lock(&slab_cache_lock);
list_remove(&cache->link);
spinlock_unlock(&slab_cache_lock);
interrupts_restore(ipl);
/* Do not lock anything, we assume the software is correct and
* does not touch the cache when it decides to destroy it */
/* Destroy all magazines */
_slab_reclaim(cache, SLAB_RECLAIM_ALL);
/* All slabs must be empty */
if (!list_empty(&cache->full_slabs) \
|| !list_empty(&cache->partial_slabs))
panic("Destroying cache that is not empty.");
if (!(cache->flags & SLAB_CACHE_NOMAGAZINE))
free(cache->mag_cache);
slab_free(&slab_cache_cache, cache);
}
/** Allocate new object from cache - if no flags given, always returns
memory */
void * slab_alloc(slab_cache_t *cache, int flags)
{
ipl_t ipl;
void *result = NULL;
/* Disable interrupts to avoid deadlocks with interrupt handlers */
ipl = interrupts_disable();
if (!(cache->flags & SLAB_CACHE_NOMAGAZINE)) {
result = magazine_obj_get(cache);
}
if (!result)
result = slab_obj_create(cache, flags);
interrupts_restore(ipl);
if (result)
atomic_inc(&cache->allocated_objs);
return result;
}
/** Return object to cache, use slab if known */
static void _slab_free(slab_cache_t *cache, void *obj, slab_t *slab)
{
ipl_t ipl;
ipl = interrupts_disable();
if ((cache->flags & SLAB_CACHE_NOMAGAZINE) \
|| magazine_obj_put(cache, obj)) {
slab_obj_destroy(cache, obj, slab);
}
interrupts_restore(ipl);
atomic_dec(&cache->allocated_objs);
}
/** Return slab object to cache */
void slab_free(slab_cache_t *cache, void *obj)
{
_slab_free(cache,obj,NULL);
}
/* Go through all caches and reclaim what is possible */
count_t slab_reclaim(int flags)
{
slab_cache_t *cache;
link_t *cur;
count_t frames = 0;
spinlock_lock(&slab_cache_lock);
/* TODO: Add assert, that interrupts are disabled, otherwise
* memory allocation from interrupts can deadlock.
*/
for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
cache = list_get_instance(cur, slab_cache_t, link);
frames += _slab_reclaim(cache, flags);
}
spinlock_unlock(&slab_cache_lock);
return frames;
}
/* Print list of slabs */
void slab_print_list(void)
{
slab_cache_t *cache;
link_t *cur;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&slab_cache_lock);
printf("slab name\t Osize\t Pages\t Obj/pg\t Slabs\t Cached\tAllocobjs\tCtl\n");
for (cur = slab_cache_list.next;cur!=&slab_cache_list; cur=cur->next) {
cache = list_get_instance(cur, slab_cache_t, link);
printf("%s\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t%7zd\t\t%s\n", cache->name, cache->size,
(1 << cache->order), cache->objects,
atomic_get(&cache->allocated_slabs),
atomic_get(&cache->cached_objs),
atomic_get(&cache->allocated_objs),
cache->flags & SLAB_CACHE_SLINSIDE ? "In" : "Out");
}
spinlock_unlock(&slab_cache_lock);
interrupts_restore(ipl);
}
void slab_cache_init(void)
{
int i, size;
/* Initialize magazine cache */
_slab_cache_create(&mag_cache,
"slab_magazine",
sizeof(slab_magazine_t)+SLAB_MAG_SIZE*sizeof(void*),
sizeof(__address),
NULL, NULL,
SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
/* Initialize slab_cache cache */
_slab_cache_create(&slab_cache_cache,
"slab_cache",
sizeof(slab_cache_cache),
sizeof(__address),
NULL, NULL,
SLAB_CACHE_NOMAGAZINE | SLAB_CACHE_SLINSIDE);
/* Initialize external slab cache */
slab_extern_cache = slab_cache_create("slab_extern",
sizeof(slab_t),
0, NULL, NULL,
SLAB_CACHE_SLINSIDE | SLAB_CACHE_MAGDEFERRED);
/* Initialize structures for malloc */
for (i=0, size=(1<<SLAB_MIN_MALLOC_W);
i < (SLAB_MAX_MALLOC_W-SLAB_MIN_MALLOC_W+1);
i++, size <<= 1) {
malloc_caches[i] = slab_cache_create(malloc_names[i],
size, 0,
NULL,NULL, SLAB_CACHE_MAGDEFERRED);
}
#ifdef CONFIG_DEBUG
_slab_initialized = 1;
#endif
}
/** Enable cpu_cache
*
* Kernel calls this function, when it knows the real number of
* processors.
* Allocate slab for cpucache and enable it on all existing
* slabs that are SLAB_CACHE_MAGDEFERRED
*/
void slab_enable_cpucache(void)
{
link_t *cur;
slab_cache_t *s;
#ifdef CONFIG_DEBUG
_slab_initialized = 2;
#endif
spinlock_lock(&slab_cache_lock);
for (cur=slab_cache_list.next; cur != &slab_cache_list;cur=cur->next){
s = list_get_instance(cur, slab_cache_t, link);
if ((s->flags & SLAB_CACHE_MAGDEFERRED) != SLAB_CACHE_MAGDEFERRED)
continue;
make_magcache(s);
s->flags &= ~SLAB_CACHE_MAGDEFERRED;
}
spinlock_unlock(&slab_cache_lock);
}
/**************************************/
/* kalloc/kfree functions */
void * malloc(unsigned int size, int flags)
{
int idx;
ASSERT(_slab_initialized);
ASSERT(size && size <= (1 << SLAB_MAX_MALLOC_W));
if (size < (1 << SLAB_MIN_MALLOC_W))
size = (1 << SLAB_MIN_MALLOC_W);
idx = fnzb(size-1) - SLAB_MIN_MALLOC_W + 1;
return slab_alloc(malloc_caches[idx], flags);
}
void free(void *obj)
{
slab_t *slab;
if (!obj) return;
slab = obj2slab(obj);
_slab_free(slab->cache, obj, slab);
}

/tags/0.1.1/kernel/generic/src/mm/frame.c
0,0 → 1,1119
/*
* Copyright (C) 2001-2005 Jakub Jermar
* Copyright (C) 2005 Sergey Bondari
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file frame.c
* @brief Physical frame allocator.
*
* This file contains the physical frame allocator and memory zone management.
* The frame allocator is built on top of the buddy allocator.
*
* @see buddy.c
*/
/*
* Locking order
*
* In order to access particular zone, the process must first lock
* the zones.lock, then lock the zone and then unlock the zones.lock.
* This insures, that we can fiddle with the zones in runtime without
* affecting the processes.
*
*/
#include <typedefs.h>
#include <arch/types.h>
#include <mm/frame.h>
#include <mm/as.h>
#include <panic.h>
#include <debug.h>
#include <adt/list.h>
#include <synch/spinlock.h>
#include <arch/asm.h>
#include <arch.h>
#include <print.h>
#include <align.h>
#include <mm/slab.h>
#include <bitops.h>
#include <macros.h>
typedef struct {
count_t refcount; /**< tracking of shared frames */
__u8 buddy_order; /**< buddy system block order */
link_t buddy_link; /**< link to the next free block inside one order */
void *parent; /**< If allocated by slab, this points there */
} frame_t;
typedef struct {
SPINLOCK_DECLARE(lock); /**< this lock protects everything below */
pfn_t base; /**< frame_no of the first frame in the frames array */
count_t count; /**< Size of zone */
frame_t *frames; /**< array of frame_t structures in this zone */
count_t free_count; /**< number of free frame_t structures */
count_t busy_count; /**< number of busy frame_t structures */
buddy_system_t * buddy_system; /**< buddy system for the zone */
int flags;
} zone_t;
/*
* The zoneinfo.lock must be locked when accessing zoneinfo structure.
* Some of the attributes in zone_t structures are 'read-only'
*/
struct {
SPINLOCK_DECLARE(lock);
int count;
zone_t *info[ZONES_MAX];
} zones;
/*********************************/
/* Helper functions */
static inline index_t frame_index(zone_t *zone, frame_t *frame)
{
return (index_t)(frame - zone->frames);
}
static inline index_t frame_index_abs(zone_t *zone, frame_t *frame)
{
return (index_t)(frame - zone->frames) + zone->base;
}
static inline int frame_index_valid(zone_t *zone, index_t index)
{
return index >= 0 && index < zone->count;
}
/** Compute pfn_t from frame_t pointer & zone pointer */
static index_t make_frame_index(zone_t *zone, frame_t *frame)
{
return frame - zone->frames;
}
/** Initialize frame structure
*
* Initialize frame structure.
*
* @param frame Frame structure to be initialized.
*/
static void frame_initialize(frame_t *frame)
{
frame->refcount = 1;
frame->buddy_order = 0;
}
/*************************************/
/* Zoneinfo functions */
/**
* Insert-sort zone into zones list
*
* @return zone number on success, -1 on error
*/
static int zones_add_zone(zone_t *newzone)
{
int i,j;
ipl_t ipl;
zone_t *z;
ipl = interrupts_disable();
spinlock_lock(&zones.lock);
/* Try to merge */
if (zones.count + 1 == ZONES_MAX)
panic("Maximum zone(%d) count exceeded.", ZONES_MAX);
for (i = 0; i < zones.count; i++) {
/* Check for overflow */
z = zones.info[i];
if (overlaps(newzone->base,newzone->count,
z->base, z->count)) {
printf("Zones overlap!\n");
return -1;
}
if (newzone->base < z->base)
break;
}
/* Move other zones up */
for (j = i;j < zones.count; j++)
zones.info[j + 1] = zones.info[j];
zones.info[i] = newzone;
zones.count++;
spinlock_unlock(&zones.lock);
interrupts_restore(ipl);
return i;
}
/**
* Try to find a zone where can we find the frame
*
* @param hint Start searching in zone 'hint'
* @param lock Lock zone if true
*
* Assume interrupts disable
*/
static zone_t * find_zone_and_lock(pfn_t frame, int *pzone)
{
int i;
int hint = pzone ? *pzone : 0;
zone_t *z;
spinlock_lock(&zones.lock);
if (hint >= zones.count || hint < 0)
hint = 0;
i = hint;
do {
z = zones.info[i];
spinlock_lock(&z->lock);
if (z->base <= frame && z->base + z->count > frame) {
spinlock_unlock(&zones.lock); /* Unlock the global lock */
if (pzone)
*pzone = i;
return z;
}
spinlock_unlock(&z->lock);
i++;
if (i >= zones.count)
i = 0;
} while(i != hint);
spinlock_unlock(&zones.lock);
return NULL;
}
/** @return True if zone can allocate specified order */
static int zone_can_alloc(zone_t *z, __u8 order)
{
return buddy_system_can_alloc(z->buddy_system, order);
}
/**
* Find AND LOCK zone that can allocate order frames
*
* Assume interrupts are disabled!!
*
* @param pzone Pointer to preferred zone or NULL, on return contains zone number
*/
static zone_t * find_free_zone_lock(__u8 order, int *pzone)
{
int i;
zone_t *z;
int hint = pzone ? *pzone : 0;
spinlock_lock(&zones.lock);
if (hint >= zones.count)
hint = 0;
i = hint;
do {
z = zones.info[i];
spinlock_lock(&z->lock);
/* Check if the zone has 2^order frames area available */
if (zone_can_alloc(z, order)) {
spinlock_unlock(&zones.lock);
if (pzone)
*pzone = i;
return z;
}
spinlock_unlock(&z->lock);
if (++i >= zones.count)
i = 0;
} while(i != hint);
spinlock_unlock(&zones.lock);
return NULL;
}
/********************************************/
/* Buddy system functions */
/** Buddy system find_block implementation
*
* Find block that is parent of current list.
* That means go to lower addresses, until such block is found
*
* @param order - Order of parent must be different then this parameter!!
*/
static link_t *zone_buddy_find_block(buddy_system_t *b, link_t *child,
__u8 order)
{
frame_t * frame;
zone_t * zone;
index_t index;
frame = list_get_instance(child, frame_t, buddy_link);
zone = (zone_t *) b->data;
index = frame_index(zone, frame);
do {
if (zone->frames[index].buddy_order != order) {
return &zone->frames[index].buddy_link;
}
} while(index-- > 0);
return NULL;
}
static void zone_buddy_print_id(buddy_system_t *b, link_t *block)
{
frame_t * frame;
zone_t * zone;
index_t index;
frame = list_get_instance(block, frame_t, buddy_link);
zone = (zone_t *) b->data;
index = frame_index(zone, frame);
printf("%zd", index);
}
/** Buddy system find_buddy implementation
*
* @param b Buddy system.
* @param block Block for which buddy should be found
*
* @return Buddy for given block if found
*/
static link_t * zone_buddy_find_buddy(buddy_system_t *b, link_t * block)
{
frame_t * frame;
zone_t * zone;
index_t index;
bool is_left, is_right;
frame = list_get_instance(block, frame_t, buddy_link);
zone = (zone_t *) b->data;
ASSERT(IS_BUDDY_ORDER_OK(frame_index_abs(zone, frame), frame->buddy_order));
is_left = IS_BUDDY_LEFT_BLOCK_ABS(zone, frame);
is_right = IS_BUDDY_RIGHT_BLOCK_ABS(zone, frame);
ASSERT(is_left ^ is_right);
if (is_left) {
index = (frame_index(zone, frame)) + (1 << frame->buddy_order);
} else { // if (is_right)
index = (frame_index(zone, frame)) - (1 << frame->buddy_order);
}
if (frame_index_valid(zone, index)) {
if (zone->frames[index].buddy_order == frame->buddy_order &&
zone->frames[index].refcount == 0) {
return &zone->frames[index].buddy_link;
}
}
return NULL;
}
/** Buddy system bisect implementation
*
* @param b Buddy system.
* @param block Block to bisect
*
* @return right block
*/
static link_t * zone_buddy_bisect(buddy_system_t *b, link_t * block) {
frame_t * frame_l, * frame_r;
frame_l = list_get_instance(block, frame_t, buddy_link);
frame_r = (frame_l + (1 << (frame_l->buddy_order - 1)));
return &frame_r->buddy_link;
}
/** Buddy system coalesce implementation
*
* @param b Buddy system.
* @param block_1 First block
* @param block_2 First block's buddy
*
* @return Coalesced block (actually block that represents lower address)
*/
static link_t * zone_buddy_coalesce(buddy_system_t *b, link_t * block_1,
link_t * block_2)
{
frame_t *frame1, *frame2;
frame1 = list_get_instance(block_1, frame_t, buddy_link);
frame2 = list_get_instance(block_2, frame_t, buddy_link);
return frame1 < frame2 ? block_1 : block_2;
}
/** Buddy system set_order implementation
*
* @param b Buddy system.
* @param block Buddy system block
* @param order Order to set
*/
static void zone_buddy_set_order(buddy_system_t *b, link_t * block, __u8 order) {
frame_t * frame;
frame = list_get_instance(block, frame_t, buddy_link);
frame->buddy_order = order;
}
/** Buddy system get_order implementation
*
* @param b Buddy system.
* @param block Buddy system block
*
* @return Order of block
*/
static __u8 zone_buddy_get_order(buddy_system_t *b, link_t * block) {
frame_t * frame;
frame = list_get_instance(block, frame_t, buddy_link);
return frame->buddy_order;
}
/** Buddy system mark_busy implementation
*
* @param b Buddy system
* @param block Buddy system block
*
*/
static void zone_buddy_mark_busy(buddy_system_t *b, link_t * block) {
frame_t * frame;
frame = list_get_instance(block, frame_t, buddy_link);
frame->refcount = 1;
}
/** Buddy system mark_available implementation
*
* @param b Buddy system
* @param block Buddy system block
*
*/
static void zone_buddy_mark_available(buddy_system_t *b, link_t * block) {
frame_t * frame;
frame = list_get_instance(block, frame_t, buddy_link);
frame->refcount = 0;
}
static struct buddy_system_operations zone_buddy_system_operations = {
.find_buddy = zone_buddy_find_buddy,
.bisect = zone_buddy_bisect,
.coalesce = zone_buddy_coalesce,
.set_order = zone_buddy_set_order,
.get_order = zone_buddy_get_order,
.mark_busy = zone_buddy_mark_busy,
.mark_available = zone_buddy_mark_available,
.find_block = zone_buddy_find_block,
.print_id = zone_buddy_print_id
};
/*************************************/
/* Zone functions */
/** Allocate frame in particular zone
*
* Assume zone is locked
* Panics if allocation is impossible.
*
* @param zone Zone to allocate from.
* @param order Allocate exactly 2^order frames.
*
* @return Frame index in zone
*
*/
static pfn_t zone_frame_alloc(zone_t *zone, __u8 order)
{
pfn_t v;
link_t *tmp;
frame_t *frame;
/* Allocate frames from zone buddy system */
tmp = buddy_system_alloc(zone->buddy_system, order);
ASSERT(tmp);
/* Update zone information. */
zone->free_count -= (1 << order);
zone->busy_count += (1 << order);
/* Frame will be actually a first frame of the block. */
frame = list_get_instance(tmp, frame_t, buddy_link);
/* get frame address */
v = make_frame_index(zone, frame);
return v;
}
/** Free frame from zone
*
* Assume zone is locked
*/
static void zone_frame_free(zone_t *zone, index_t frame_idx)
{
frame_t *frame;
__u8 order;
frame = &zone->frames[frame_idx];
/* remember frame order */
order = frame->buddy_order;
ASSERT(frame->refcount);
if (!--frame->refcount) {
buddy_system_free(zone->buddy_system, &frame->buddy_link);
/* Update zone information. */
zone->free_count += (1 << order);
zone->busy_count -= (1 << order);
}
}
/** Return frame from zone */
static frame_t * zone_get_frame(zone_t *zone, index_t frame_idx)
{
ASSERT(frame_idx < zone->count);
return &zone->frames[frame_idx];
}
/** Mark frame in zone unavailable to allocation */
static void zone_mark_unavailable(zone_t *zone, index_t frame_idx)
{
frame_t *frame;
link_t *link;
frame = zone_get_frame(zone, frame_idx);
if (frame->refcount)
return;
link = buddy_system_alloc_block(zone->buddy_system,
&frame->buddy_link);
ASSERT(link);
zone->free_count--;
}
/**
* Join 2 zones
*
* Expect zone_t *z to point to space at least zone_conf_size large
*
* Assume z1 & z2 are locked
*/
static void _zone_merge(zone_t *z, zone_t *z1, zone_t *z2)
{
__u8 max_order;
int i, z2idx;
pfn_t frame_idx;
frame_t *frame;
ASSERT(!overlaps(z1->base,z1->count,z2->base,z2->count));
ASSERT(z1->base < z2->base);
spinlock_initialize(&z->lock, "zone_lock");
z->base = z1->base;
z->count = z2->base+z2->count - z1->base;
z->flags = z1->flags & z2->flags;
z->free_count = z1->free_count + z2->free_count;
z->busy_count = z1->busy_count + z2->busy_count;
max_order = fnzb(z->count);
z->buddy_system = (buddy_system_t *)&z[1];
buddy_system_create(z->buddy_system, max_order,
&zone_buddy_system_operations,
(void *) z);
z->frames = (frame_t *)((void *)z->buddy_system+buddy_conf_size(max_order));
for (i = 0; i < z->count; i++) {
/* This marks all frames busy */
frame_initialize(&z->frames[i]);
}
/* Copy frames from both zones to preserve full frame orders,
* parents etc. Set all free frames with refcount=0 to 1, because
* we add all free frames to buddy allocator later again, clear
* order to 0. Don't set busy frames with refcount=0, as they
* will not be reallocated during merge and it would make later
* problems with allocation/free.
*/
for (i=0; i<z1->count; i++)
z->frames[i] = z1->frames[i];
for (i=0; i < z2->count; i++) {
z2idx = i + (z2->base - z1->base);
z->frames[z2idx] = z2->frames[i];
}
i = 0;
while (i < z->count) {
if (z->frames[i].refcount) {
/* skip busy frames */
i += 1 << z->frames[i].buddy_order;
} else { /* Free frames, set refcount=1 */
/* All free frames have refcount=0, we need not
* to check the order */
z->frames[i].refcount = 1;
z->frames[i].buddy_order = 0;
i++;
}
}
/* Add free blocks from the 2 original zones */
while (zone_can_alloc(z1, 0)) {
frame_idx = zone_frame_alloc(z1, 0);
frame = &z->frames[frame_idx];
frame->refcount = 0;
buddy_system_free(z->buddy_system, &frame->buddy_link);
}
while (zone_can_alloc(z2, 0)) {
frame_idx = zone_frame_alloc(z2, 0);
frame = &z->frames[frame_idx + (z2->base-z1->base)];
frame->refcount = 0;
buddy_system_free(z->buddy_system, &frame->buddy_link);
}
}
/** Return old configuration frames into the zone
*
* We have several cases
* - the conf. data is outside of zone -> exit, shall we call frame_free??
* - the conf. data was created by zone_create or
* updated with reduce_region -> free every frame
*
* @param newzone The actual zone where freeing should occur
* @param oldzone Pointer to old zone configuration data that should
* be freed from new zone
*/
static void return_config_frames(zone_t *newzone, zone_t *oldzone)
{
pfn_t pfn;
frame_t *frame;
count_t cframes;
int i;
pfn = ADDR2PFN((__address)KA2PA(oldzone));
cframes = SIZE2FRAMES(zone_conf_size(oldzone->count));
if (pfn < newzone->base || pfn >= newzone->base + newzone->count)
return;
frame = &newzone->frames[pfn - newzone->base];
ASSERT(!frame->buddy_order);
for (i=0; i < cframes; i++) {
newzone->busy_count++;
zone_frame_free(newzone, pfn+i-newzone->base);
}
}
/** Reduce allocated block to count of order 0 frames
*
* The allocated block need 2^order frames of space. Reduce all frames
* in block to order 0 and free the unneded frames. This means, that
* when freeing the block, you have to free every frame from block.
*
* @param zone
* @param frame_idx Index to block
* @param count Allocated space in block
*/
static void zone_reduce_region(zone_t *zone, pfn_t frame_idx, count_t count)
{
count_t i;
__u8 order;
frame_t *frame;
ASSERT(frame_idx+count < zone->count);
order = zone->frames[frame_idx].buddy_order;
ASSERT((1 << order) >= count);
/* Reduce all blocks to order 0 */
for (i=0; i < (1 << order); i++) {
frame = &zone->frames[i + frame_idx];
frame->buddy_order = 0;
if (! frame->refcount)
frame->refcount = 1;
ASSERT(frame->refcount == 1);
}
/* Free unneeded frames */
for (i=count; i < (1 << order); i++) {
zone_frame_free(zone, i + frame_idx);
}
}
/** Merge zones z1 and z2
*
* - the zones must be 2 zones with no zone existing in between,
* which means that z2 = z1+1
*
* - When you create a new zone, the frame allocator configuration does
* not to be 2^order size. Once the allocator is running it is no longer
* possible, merged configuration data occupies more space :-/
*/
void zone_merge(int z1, int z2)
{
ipl_t ipl;
zone_t *zone1, *zone2, *newzone;
int cframes;
__u8 order;
int i;
pfn_t pfn;
ipl = interrupts_disable();
spinlock_lock(&zones.lock);
if (z1 < 0 || z1 >= zones.count || z2 < 0 || z2 >= zones.count)
goto errout;
/* We can join only 2 zones with none existing inbetween */
if (z2-z1 != 1)
goto errout;
zone1 = zones.info[z1];
zone2 = zones.info[z2];
spinlock_lock(&zone1->lock);
spinlock_lock(&zone2->lock);
cframes = SIZE2FRAMES(zone_conf_size(zone2->base+zone2->count-zone1->base));
order = fnzb(cframes) + 1;
/* Allocate zonedata inside one of the zones */
if (zone_can_alloc(zone1, order))
pfn = zone1->base + zone_frame_alloc(zone1, order);
else if (zone_can_alloc(zone2, order))
pfn = zone2->base + zone_frame_alloc(zone2, order);
else
goto errout2;
newzone = (zone_t *)PA2KA(PFN2ADDR(pfn));
_zone_merge(newzone, zone1, zone2);
/* Free unneeded config frames */
zone_reduce_region(newzone, pfn - newzone->base, cframes);
/* Subtract zone information from busy frames */
newzone->busy_count -= cframes;
/* Replace existing zones in zoneinfo list */
zones.info[z1] = newzone;
for (i = z2 + 1; i < zones.count; i++)
zones.info[i - 1] = zones.info[i];
zones.count--;
/* Free old zone information */
return_config_frames(newzone, zone1);
return_config_frames(newzone, zone2);
errout2:
/* Nobody is allowed to enter to zone, so we are safe
* to touch the spinlocks last time */
spinlock_unlock(&zone1->lock);
spinlock_unlock(&zone2->lock);
errout:
spinlock_unlock(&zones.lock);
interrupts_restore(ipl);
}
/**
* Merge all zones into one big zone
*
* It is reasonable to do this on systems whose bios reports parts in chunks,
* so that we could have 1 zone (it's faster).
*/
void zone_merge_all(void)
{
int count = zones.count;
while (zones.count > 1 && --count) {
zone_merge(0,1);
break;
}
}
/** Create frame zone
*
* Create new frame zone.
*
* @param start Physical address of the first frame within the zone.
* @param size Size of the zone. Must be a multiple of FRAME_SIZE.
* @param conffram Address of configuration frame
* @param flags Zone flags.
*
* @return Initialized zone.
*/
static void zone_construct(pfn_t start, count_t count, zone_t *z, int flags)
{
int i;
__u8 max_order;
spinlock_initialize(&z->lock, "zone_lock");
z->base = start;
z->count = count;
z->flags = flags;
z->free_count = count;
z->busy_count = 0;
/*
* Compute order for buddy system, initialize
*/
max_order = fnzb(count);
z->buddy_system = (buddy_system_t *)&z[1];
buddy_system_create(z->buddy_system, max_order,
&zone_buddy_system_operations,
(void *) z);
/* Allocate frames _after_ the conframe */
/* Check sizes */
z->frames = (frame_t *)((void *)z->buddy_system+buddy_conf_size(max_order));
for (i = 0; i<count; i++) {
frame_initialize(&z->frames[i]);
}
/* Stuffing frames */
for (i = 0; i < count; i++) {
z->frames[i].refcount = 0;
buddy_system_free(z->buddy_system, &z->frames[i].buddy_link);
}
}
/** Compute configuration data size for zone */
__address zone_conf_size(count_t count)
{
int size = sizeof(zone_t) + count*sizeof(frame_t);
int max_order;
max_order = fnzb(count);
size += buddy_conf_size(max_order);
return size;
}
/** Create and add zone to system
*
* @param confframe Where configuration frame is supposed to be.
* Always check, that we will not disturb the kernel and possibly init.
* If confframe is given _outside_ this zone, it is expected,
* that the area is already marked BUSY and big enough
* to contain zone_conf_size() amount of data
*
* @return Zone number or -1 on error
*/
int zone_create(pfn_t start, count_t count, pfn_t confframe, int flags)
{
zone_t *z;
__address addr;
count_t confcount;
int i;
int znum;
/* Theoretically we could have here 0, practically make sure
* nobody tries to do that. If some platform requires, remove
* the assert
*/
ASSERT(confframe);
/* If conframe is supposed to be inside our zone, then make sure
* it does not span kernel & init
*/
confcount = SIZE2FRAMES(zone_conf_size(count));
if (confframe >= start && confframe < start+count) {
for (;confframe < start + count; confframe++) {
addr = PFN2ADDR(confframe);
if (overlaps(addr, PFN2ADDR(confcount), KA2PA(config.base), config.kernel_size))
continue;
bool overlap = false;
count_t i;
for (i = 0; i < init.cnt; i++)
if (overlaps(addr, PFN2ADDR(confcount), KA2PA(init.tasks[i].addr), init.tasks[i].size)) {
overlap = true;
break;
}
if (overlap)
continue;
break;
}
if (confframe >= start + count)
panic("Cannot find configuration data for zone.");
}
z = (zone_t *)PA2KA(PFN2ADDR(confframe));
zone_construct(start, count, z, flags);
znum = zones_add_zone(z);
if (znum == -1)
return -1;
/* If confdata in zone, mark as unavailable */
if (confframe >= start && confframe < start+count)
for (i=confframe; i<confframe+confcount; i++) {
zone_mark_unavailable(z, i - z->base);
}
return znum;
}
/***************************************/
/* Frame functions */
/** Set parent of frame */
void frame_set_parent(pfn_t pfn, void *data, int hint)
{
zone_t *zone = find_zone_and_lock(pfn, &hint);
ASSERT(zone);
zone_get_frame(zone, pfn-zone->base)->parent = data;
spinlock_unlock(&zone->lock);
}
void * frame_get_parent(pfn_t pfn, int hint)
{
zone_t *zone = find_zone_and_lock(pfn, &hint);
void *res;
ASSERT(zone);
res = zone_get_frame(zone, pfn - zone->base)->parent;
spinlock_unlock(&zone->lock);
return res;
}
/** Allocate power-of-two frames of physical memory.
*
* @param order Allocate exactly 2^order frames.
* @param flags Flags for host zone selection and address processing.
* @param status Allocation status (FRAME_OK on success), unused if NULL.
* @param pzone Preferred zone
*
* @return Allocated frame.
*
*/
pfn_t frame_alloc_generic(__u8 order, int flags, int *status, int *pzone)
{
ipl_t ipl;
int freed;
pfn_t v;
zone_t *zone;
loop:
ipl = interrupts_disable();
/*
* First, find suitable frame zone.
*/
zone = find_free_zone_lock(order, pzone);
/* If no memory, reclaim some slab memory,
if it does not help, reclaim all */
if (!zone && !(flags & FRAME_NO_RECLAIM)) {
freed = slab_reclaim(0);
if (freed)
zone = find_free_zone_lock(order, pzone);
if (!zone) {
freed = slab_reclaim(SLAB_RECLAIM_ALL);
if (freed)
zone = find_free_zone_lock(order, pzone);
}
}
if (!zone) {
if (flags & FRAME_PANIC)
panic("Can't allocate frame.\n");
/*
* TODO: Sleep until frames are available again.
*/
interrupts_restore(ipl);
if (flags & FRAME_ATOMIC) {
ASSERT(status != NULL);
if (status)
*status = FRAME_NO_MEMORY;
return NULL;
}
panic("Sleep not implemented.\n");
goto loop;
}
v = zone_frame_alloc(zone, order);
v += zone->base;
spinlock_unlock(&zone->lock);
interrupts_restore(ipl);
if (status)
*status = FRAME_OK;
return v;
}
/** Free a frame.
*
* Find respective frame structure for supplied PFN.
* Decrement frame reference count.
* If it drops to zero, move the frame structure to free list.
*
* @param frame Frame number to be freed.
*/
void frame_free(pfn_t pfn)
{
ipl_t ipl;
zone_t *zone;
ipl = interrupts_disable();
/*
* First, find host frame zone for addr.
*/
zone = find_zone_and_lock(pfn,NULL);
ASSERT(zone);
zone_frame_free(zone, pfn-zone->base);
spinlock_unlock(&zone->lock);
interrupts_restore(ipl);
}
/** Add reference to frame.
*
* Find respective frame structure for supplied PFN and
* increment frame reference count.
*
* @param frame Frame no to be freed.
*/
void frame_reference_add(pfn_t pfn)
{
ipl_t ipl;
zone_t *zone;
frame_t *frame;
ipl = interrupts_disable();
/*
* First, find host frame zone for addr.
*/
zone = find_zone_and_lock(pfn,NULL);
ASSERT(zone);
frame = &zone->frames[pfn-zone->base];
frame->refcount++;
spinlock_unlock(&zone->lock);
interrupts_restore(ipl);
}
/** Mark given range unavailable in frame zones */
void frame_mark_unavailable(pfn_t start, count_t count)
{
int i;
zone_t *zone;
int prefzone = 0;
for (i=0; i < count; i++) {
zone = find_zone_and_lock(start+i,&prefzone);
if (!zone) /* PFN not found */
continue;
zone_mark_unavailable(zone, start+i-zone->base);
spinlock_unlock(&zone->lock);
}
}
/** Initialize physical memory management
*
* Initialize physical memory managemnt.
*/
void frame_init(void)
{
if (config.cpu_active == 1) {
zones.count = 0;
spinlock_initialize(&zones.lock,"zones_glob_lock");
}
/* Tell the architecture to create some memory */
frame_arch_init();
if (config.cpu_active == 1) {
pfn_t firstframe = ADDR2PFN(KA2PA(config.base));
pfn_t lastframe = ADDR2PFN(KA2PA(config.base+config.kernel_size));
frame_mark_unavailable(firstframe,lastframe-firstframe+1);
count_t i;
for (i = 0; i < init.cnt; i++)
frame_mark_unavailable(ADDR2PFN(KA2PA(init.tasks[i].addr)), SIZE2FRAMES(init.tasks[i].size));
}
}
/** Prints list of zones
*
*/
void zone_print_list(void) {
zone_t *zone = NULL;
int i;
ipl_t ipl;
ipl = interrupts_disable();
spinlock_lock(&zones.lock);
printf("# Base address\tFree Frames\tBusy Frames\n");
printf(" ------------\t-----------\t-----------\n");
for (i = 0; i < zones.count; i++) {
zone = zones.info[i];
spinlock_lock(&zone->lock);
printf("%d: %.*p \t%10zd\t%10zd\n", i, sizeof(__address) * 2, PFN2ADDR(zone->base), zone->free_count, zone->busy_count);
spinlock_unlock(&zone->lock);
}
spinlock_unlock(&zones.lock);
interrupts_restore(ipl);
}
/** Prints zone details
*
* @param base Zone base address OR zone number
*/
void zone_print_one(int num) {
zone_t *zone = NULL;
ipl_t ipl;
int i;
ipl = interrupts_disable();
spinlock_lock(&zones.lock);
for (i = 0; i < zones.count; i++) {
if (i == num || PFN2ADDR(zones.info[i]->base) == num) {
zone = zones.info[i];
break;
}
}
if (!zone) {
printf("Zone not found.\n");
goto out;
}
spinlock_lock(&zone->lock);
printf("Memory zone information\n");
printf("Zone base address: %#.*p\n", sizeof(__address) * 2, PFN2ADDR(zone->base));
printf("Zone size: %zd frames (%zdK)\n", zone->count, ((zone->count) * FRAME_SIZE) >> 10);
printf("Allocated space: %zd frames (%zdK)\n", zone->busy_count, (zone->busy_count * FRAME_SIZE) >> 10);
printf("Available space: %zd (%zdK)\n", zone->free_count, (zone->free_count * FRAME_SIZE) >> 10);
buddy_system_structure_print(zone->buddy_system, FRAME_SIZE);
spinlock_unlock(&zone->lock);
out:
spinlock_unlock(&zones.lock);
interrupts_restore(ipl);
}

/tags/0.1.1/kernel/generic/src/mm/buddy.c
0,0 → 1,318
/*
* Copyright (C) 2005 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file buddy.c
* @brief Buddy allocator framework.
*
* This file contains buddy system allocator framework.
* Specialized functions are needed for this abstract framework
* to be useful.
*/
#include <mm/buddy.h>
#include <mm/frame.h>
#include <arch/types.h>
#include <typedefs.h>
#include <adt/list.h>
#include <debug.h>
#include <print.h>
/** Return size needed for the buddy configuration data */
size_t buddy_conf_size(int max_order)
{
return sizeof(buddy_system_t) + (max_order + 1) * sizeof(link_t);
}
/** Create buddy system
*
* Allocate memory for and initialize new buddy system.
*
* @param b Preallocated buddy system control data.
* @param max_order The biggest allocable size will be 2^max_order.
* @param op Operations for new buddy system.
* @param data Pointer to be used by implementation.
*
* @return New buddy system.
*/
void buddy_system_create(buddy_system_t *b,
__u8 max_order,
buddy_system_operations_t *op,
void *data)
{
int i;
ASSERT(max_order < BUDDY_SYSTEM_INNER_BLOCK);
ASSERT(op->find_buddy);
ASSERT(op->set_order);
ASSERT(op->get_order);
ASSERT(op->bisect);
ASSERT(op->coalesce);
ASSERT(op->mark_busy);
/*
* Use memory after our own structure
*/
b->order = (link_t *) (&b[1]);
for (i = 0; i <= max_order; i++)
list_initialize(&b->order[i]);
b->max_order = max_order;
b->op = op;
b->data = data;
}
/** Check if buddy system can allocate block
*
* @param b Buddy system pointer
* @param i Size of the block (2^i)
*
* @return True if block can be allocated
*/
bool buddy_system_can_alloc(buddy_system_t *b, __u8 i) {
__u8 k;
/*
* If requested block is greater then maximal block
* we know immediatly that we cannot satisfy the request.
*/
if (i > b->max_order) return false;
/*
* Check if any bigger or equal order has free elements
*/
for (k=i; k <= b->max_order; k++) {
if (!list_empty(&b->order[k])) {
return true;
}
}
return false;
}
/** Allocate PARTICULAR block from buddy system
*
* @ return Block of data or NULL if no such block was found
*/
link_t *buddy_system_alloc_block(buddy_system_t *b, link_t *block)
{
link_t *left,*right, *tmp;
__u8 order;
left = b->op->find_block(b, block, BUDDY_SYSTEM_INNER_BLOCK);
ASSERT(left);
list_remove(left);
while (1) {
if (! b->op->get_order(b,left)) {
b->op->mark_busy(b, left);
return left;
}
order = b->op->get_order(b, left);
right = b->op->bisect(b, left);
b->op->set_order(b, left, order-1);
b->op->set_order(b, right, order-1);
tmp = b->op->find_block(b, block, BUDDY_SYSTEM_INNER_BLOCK);
if (tmp == right) {
right = left;
left = tmp;
}
ASSERT(tmp == left);
b->op->mark_busy(b, left);
buddy_system_free(b, right);
b->op->mark_available(b, left);
}
}
/** Allocate block from buddy system.
*
* @param b Buddy system pointer.
* @param i Returned block will be 2^i big.
*
* @return Block of data represented by link_t.
*/
link_t *buddy_system_alloc(buddy_system_t *b, __u8 i)
{
link_t *res, *hlp;
ASSERT(i <= b->max_order);
/*
* If the list of order i is not empty,
* the request can be immediatelly satisfied.
*/
if (!list_empty(&b->order[i])) {
res = b->order[i].next;
list_remove(res);
b->op->mark_busy(b, res);
return res;
}
/*
* If order i is already the maximal order,
* the request cannot be satisfied.
*/
if (i == b->max_order)
return NULL;
/*
* Try to recursively satisfy the request from higher order lists.
*/
hlp = buddy_system_alloc(b, i + 1);
/*
* The request could not be satisfied
* from higher order lists.
*/
if (!hlp)
return NULL;
res = hlp;
/*
* Bisect the block and set order of both of its parts to i.
*/
hlp = b->op->bisect(b, res);
b->op->set_order(b, res, i);
b->op->set_order(b, hlp, i);
/*
* Return the other half to buddy system. Mark the first part
* full, so that it won't coalesce again.
*/
b->op->mark_busy(b, res);
buddy_system_free(b, hlp);
return res;
}
/** Return block to buddy system.
*
* @param b Buddy system pointer.
* @param block Block to return.
*/
void buddy_system_free(buddy_system_t *b, link_t *block)
{
link_t *buddy, *hlp;
__u8 i;
/*
* Determine block's order.
*/
i = b->op->get_order(b, block);
ASSERT(i <= b->max_order);
if (i != b->max_order) {
/*
* See if there is any buddy in the list of order i.
*/
buddy = b->op->find_buddy(b, block);
if (buddy) {
ASSERT(b->op->get_order(b, buddy) == i);
/*
* Remove buddy from the list of order i.
*/
list_remove(buddy);
/*
* Invalidate order of both block and buddy.
*/
b->op->set_order(b, block, BUDDY_SYSTEM_INNER_BLOCK);
b->op->set_order(b, buddy, BUDDY_SYSTEM_INNER_BLOCK);
/*
* Coalesce block and buddy into one block.
*/
hlp = b->op->coalesce(b, block, buddy);
/*
* Set order of the coalesced block to i + 1.
*/
b->op->set_order(b, hlp, i + 1);
/*
* Recursively add the coalesced block to the list of order i + 1.
*/
buddy_system_free(b, hlp);
return;
}
}
/*
* Insert block into the list of order i.
*/
list_append(block, &b->order[i]);
}
/** Prints out structure of buddy system
*
* @param b Pointer to buddy system
* @param es Element size
*/
void buddy_system_structure_print(buddy_system_t *b, size_t elem_size) {
index_t i;
count_t cnt, elem_count = 0, block_count = 0;
link_t * cur;
printf("Order\tBlocks\tSize \tBlock size\tElems per block\n");
printf("-----\t------\t--------\t----------\t---------------\n");
for (i=0;i <= b->max_order; i++) {
cnt = 0;
if (!list_empty(&b->order[i])) {
for (cur = b->order[i].next; cur != &b->order[i]; cur = cur->next)
cnt++;
}
printf("#%zd\t%5zd\t%7zdK\t%8zdK\t%6zd\t", i, cnt, (cnt * (1 << i) * elem_size) >> 10, ((1 << i) * elem_size) >> 10, 1 << i);
if (!list_empty(&b->order[i])) {
for (cur = b->order[i].next; cur != &b->order[i]; cur = cur->next) {
b->op->print_id(b, cur);
printf(" ");
}
}
printf("\n");
block_count += cnt;
elem_count += (1 << i) * cnt;
}
printf("-----\t------\t--------\t----------\t---------------\n");
printf("Buddy system contains %zd free elements (%zd blocks)\n" , elem_count, block_count);
}

/tags/0.1.1/kernel/generic/src/mm/page.c
0,0 → 1,136
/*
* Copyright (C) 2001-2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file page.c
* @brief Virtual Address Translation subsystem.
*
* This file contains code for creating, destroying and searching
* mappings between virtual addresses and physical addresses.
* Functions here are mere wrappers that call the real implementation.
* They however, define the single interface.
*/
#include <mm/page.h>
#include <arch/mm/page.h>
#include <arch/mm/asid.h>
#include <mm/as.h>
#include <mm/frame.h>
#include <arch/types.h>
#include <typedefs.h>
#include <arch/asm.h>
#include <memstr.h>
#include <debug.h>
#include <arch.h>
/** Virtual operations for page subsystem. */
page_mapping_operations_t *page_mapping_operations = NULL;
void page_init(void)
{
page_arch_init();
}
/** Map memory structure
*
* Identity-map memory structure
* considering possible crossings
* of page boundaries.
*
* @param s Address of the structure.
* @param size Size of the structure.
*/
void map_structure(__address s, size_t size)
{
int i, cnt, length;
length = size + (s - (s & ~(PAGE_SIZE - 1)));
cnt = length / PAGE_SIZE + (length % PAGE_SIZE > 0);
for (i = 0; i < cnt; i++)
page_mapping_insert(AS_KERNEL, s + i * PAGE_SIZE, s + i * PAGE_SIZE, PAGE_NOT_CACHEABLE);
}
/** Insert mapping of page to frame.
*
* Map virtual address page to physical address frame
* using flags. Allocate and setup any missing page tables.
*
* The page table must be locked and interrupts must be disabled.
*
* @param as Address space to wich page belongs.
* @param page Virtual address of the page to be mapped.
* @param frame Physical address of memory frame to which the mapping is done.
* @param flags Flags to be used for mapping.
*/
void page_mapping_insert(as_t *as, __address page, __address frame, int flags)
{
ASSERT(page_mapping_operations);
ASSERT(page_mapping_operations->mapping_insert);
page_mapping_operations->mapping_insert(as, page, frame, flags);
}
/** Remove mapping of page.
*
* Remove any mapping of page within address space as.
* TLB shootdown should follow in order to make effects of
* this call visible.
*
* The page table must be locked and interrupts must be disabled.
*
* @param as Address space to wich page belongs.
* @param page Virtual address of the page to be demapped.
*/
void page_mapping_remove(as_t *as, __address page)
{
ASSERT(page_mapping_operations);
ASSERT(page_mapping_operations->mapping_remove);
page_mapping_operations->mapping_remove(as, page);
}
/** Find mapping for virtual page
*
* Find mapping for virtual page.
*
* The page table must be locked and interrupts must be disabled.
*
* @param as Address space to wich page belongs.
* @param page Virtual page.
*
* @return NULL if there is no such mapping; requested mapping otherwise.
*/
pte_t *page_mapping_find(as_t *as, __address page)
{
ASSERT(page_mapping_operations);
ASSERT(page_mapping_operations->mapping_find);
return page_mapping_operations->mapping_find(as, page);
}