| 0,0 → 1,1537 |
|---|
| /* |
| * 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. |
| */ |
| |
| /** @addtogroup genericmm |
| * @{ |
| */ |
| |
| /** |
| * @file |
| * @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 spaces 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 <synch/mutex.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 <align.h> |
| #include <arch/types.h> |
| #include <typedefs.h> |
| #include <syscall/copy.h> |
| #include <arch/interrupt.h> |
| |
| /** |
| * Each architecture decides what functions will be used to carry out |
| * address space operations such as creating or locking page tables. |
| */ |
| as_operations_t *as_operations = NULL; |
| |
| /** This lock protects inactive_as_with_asid_head list. It must be acquired before as_t mutex. */ |
| SPINLOCK_INITIALIZE(inactive_as_with_asid_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 as_area_t *find_area_and_lock(as_t *as, uintptr_t va); |
| static bool check_area_conflicts(as_t *as, uintptr_t va, size_t size, as_area_t *avoid_area); |
| static void sh_info_remove_reference(share_info_t *sh_info); |
| |
| /** 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); |
| mutex_initialize(&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->cpu_refcount = 0; |
| as->page_table = page_table_create(flags); |
| |
| return as; |
| } |
| |
| /** Destroy adress space. |
| * |
| * When there are no tasks referencing this address space (i.e. its refcount is zero), |
| * the address space can be destroyed. |
| */ |
| void as_destroy(as_t *as) |
| { |
| ipl_t ipl; |
| bool cond; |
| |
| ASSERT(as->refcount == 0); |
| |
| /* |
| * Since there is no reference to this area, |
| * it is safe not to lock its mutex. |
| */ |
| ipl = interrupts_disable(); |
| spinlock_lock(&inactive_as_with_asid_lock); |
| if (as->asid != ASID_INVALID && as != AS_KERNEL) { |
| if (as != AS && as->cpu_refcount == 0) |
| list_remove(&as->inactive_as_with_asid_link); |
| asid_put(as->asid); |
| } |
| spinlock_unlock(&inactive_as_with_asid_lock); |
| |
| /* |
| * Destroy address space areas of the address space. |
| * The B+tee must be walked carefully because it is |
| * also being destroyed. |
| */ |
| for (cond = true; cond; ) { |
| btree_node_t *node; |
| |
| ASSERT(!list_empty(&as->as_area_btree.leaf_head)); |
| node = list_get_instance(as->as_area_btree.leaf_head.next, btree_node_t, leaf_link); |
| |
| if ((cond = node->keys)) { |
| as_area_destroy(as, node->key[0]); |
| } |
| } |
| |
| btree_destroy(&as->as_area_btree); |
| page_table_destroy(as->page_table); |
| |
| interrupts_restore(ipl); |
| |
| 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. |
| * @param backend Address space area backend. NULL if no backend is used. |
| * @param backend_data NULL or a pointer to an array holding two void *. |
| * |
| * @return Address space area on success or NULL on failure. |
| */ |
| as_area_t *as_area_create(as_t *as, int flags, size_t size, uintptr_t base, int attrs, |
| mem_backend_t *backend, mem_backend_data_t *backend_data) |
| { |
| 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(); |
| mutex_lock(&as->lock); |
| |
| if (!check_area_conflicts(as, base, size, NULL)) { |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return NULL; |
| } |
| |
| a = (as_area_t *) malloc(sizeof(as_area_t), 0); |
| |
| mutex_initialize(&a->lock); |
| |
| a->as = as; |
| a->flags = flags; |
| a->attributes = attrs; |
| a->pages = SIZE2FRAMES(size); |
| a->base = base; |
| a->sh_info = NULL; |
| a->backend = backend; |
| if (backend_data) |
| a->backend_data = *backend_data; |
| else |
| memsetb((uintptr_t) &a->backend_data, sizeof(a->backend_data), 0); |
| |
| btree_create(&a->used_space); |
| |
| btree_insert(&as->as_area_btree, base, (void *) a, NULL); |
| |
| mutex_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, uintptr_t address, size_t size, int flags) |
| { |
| as_area_t *area; |
| ipl_t ipl; |
| size_t pages; |
| |
| ipl = interrupts_disable(); |
| mutex_lock(&as->lock); |
| |
| /* |
| * Locate the area. |
| */ |
| area = find_area_and_lock(as, address); |
| if (!area) { |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return ENOENT; |
| } |
| |
| if (area->backend == &phys_backend) { |
| /* |
| * Remapping of address space areas associated |
| * with memory mapped devices is not supported. |
| */ |
| mutex_unlock(&area->lock); |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return ENOTSUP; |
| } |
| if (area->sh_info) { |
| /* |
| * Remapping of shared address space areas |
| * is not supported. |
| */ |
| mutex_unlock(&area->lock); |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return ENOTSUP; |
| } |
| |
| pages = SIZE2FRAMES((address - area->base) + size); |
| if (!pages) { |
| /* |
| * Zero size address space areas are not allowed. |
| */ |
| mutex_unlock(&area->lock); |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return EPERM; |
| } |
| |
| if (pages < area->pages) { |
| bool cond; |
| uintptr_t start_free = area->base + pages*PAGE_SIZE; |
| |
| /* |
| * Shrinking the area. |
| * No need to check for overlaps. |
| */ |
| |
| /* |
| * Start TLB shootdown sequence. |
| */ |
| tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base + pages*PAGE_SIZE, area->pages - pages); |
| |
| /* |
| * Remove frames belonging to used space starting from |
| * the highest addresses downwards until an overlap with |
| * the resized address space area is found. Note that this |
| * is also the right way to remove part of the used_space |
| * B+tree leaf list. |
| */ |
| for (cond = true; cond;) { |
| btree_node_t *node; |
| |
| ASSERT(!list_empty(&area->used_space.leaf_head)); |
| node = list_get_instance(area->used_space.leaf_head.prev, btree_node_t, leaf_link); |
| if ((cond = (bool) node->keys)) { |
| uintptr_t b = node->key[node->keys - 1]; |
| count_t c = (count_t) node->value[node->keys - 1]; |
| int i = 0; |
| |
| if (overlaps(b, c*PAGE_SIZE, area->base, pages*PAGE_SIZE)) { |
| |
| if (b + c*PAGE_SIZE <= start_free) { |
| /* |
| * The whole interval fits completely |
| * in the resized address space area. |
| */ |
| break; |
| } |
| |
| /* |
| * Part of the interval corresponding to b and c |
| * overlaps with the resized address space area. |
| */ |
| |
| cond = false; /* we are almost done */ |
| i = (start_free - b) >> PAGE_WIDTH; |
| if (!used_space_remove(area, start_free, c - i)) |
| panic("Could not remove used space."); |
| } else { |
| /* |
| * The interval of used space can be completely removed. |
| */ |
| if (!used_space_remove(area, b, c)) |
| panic("Could not remove used space.\n"); |
| } |
| |
| for (; i < c; i++) { |
| pte_t *pte; |
| |
| page_table_lock(as, false); |
| pte = page_mapping_find(as, b + i*PAGE_SIZE); |
| ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte)); |
| if (area->backend && area->backend->frame_free) { |
| area->backend->frame_free(area, |
| b + i*PAGE_SIZE, PTE_GET_FRAME(pte)); |
| } |
| page_mapping_remove(as, b + i*PAGE_SIZE); |
| page_table_unlock(as, false); |
| } |
| } |
| } |
| |
| /* |
| * Finish TLB shootdown sequence. |
| */ |
| 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)) { |
| mutex_unlock(&area->lock); |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return EADDRNOTAVAIL; |
| } |
| } |
| |
| area->pages = pages; |
| |
| mutex_unlock(&area->lock); |
| mutex_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, uintptr_t address) |
| { |
| as_area_t *area; |
| uintptr_t base; |
| link_t *cur; |
| ipl_t ipl; |
| |
| ipl = interrupts_disable(); |
| mutex_lock(&as->lock); |
| |
| area = find_area_and_lock(as, address); |
| if (!area) { |
| mutex_unlock(&as->lock); |
| interrupts_restore(ipl); |
| return ENOENT; |
| } |
| |
| base = area->base; |
| |
| /* |
| * Start TLB shootdown sequence. |
| */ |
| tlb_shootdown_start(TLB_INVL_PAGES, AS->asid, area->base, area->pages); |
| |
| /* |
| * Visit only the pages mapped by used_space B+tree. |
| */ |
| for (cur = area->used_space.leaf_head.next; cur != &area->used_space.leaf_head; cur = cur->next) { |
| btree_node_t *node; |
| int i; |
| |
| node = list_get_instance(cur, btree_node_t, leaf_link); |
| for (i = 0; i < node->keys; i++) { |
| uintptr_t b = node->key[i]; |
| count_t j; |
| pte_t *pte; |
| |
| for (j = 0; j < (count_t) node->value[i]; j++) { |
| page_table_lock(as, false); |
| pte = page_mapping_find(as, b + j*PAGE_SIZE); |
| ASSERT(pte && PTE_VALID(pte) && PTE_PRESENT(pte)); |
| if (area->backend && area->backend->frame_free) { |
| area->backend->frame_free(area, |
| b + j*PAGE_SIZE, PTE_GET_FRAME(pte)); |
| } |
| page_mapping_remove(as, b + j*PAGE_SIZE); |
| page_table_unlock(as, false); |
| } |
| } |
| } |
| |
| /* |
| * Finish TLB shootdown sequence. |
| */ |
| tlb_invalidate_pages(AS->asid, area->base, area->pages); |
| tlb_shootdown_finalize(); |
| |
| btree_destroy(&area->used_space); |
| |
| area->attributes |= AS_AREA_ATTR_PARTIAL; |
| |
| if (area->sh_info) |
| sh_info_remove_reference(area->sh_info); |
| |
| mutex_unlock(&area->lock); |
| |
| /* |
| * Remove the empty area from address space. |
| */ |
| btree_remove(&AS->as_area_btree, base, NULL); |
| |
| free(area); |
| |
| mutex_unlock(&AS->lock); |
| interrupts_restore(ipl); |
| return 0; |
| } |
| |
| /** Share address space area with another or the same address space. |
| * |
| * Address space area mapping is shared with a new address space area. |
| * If the source address space area has not been shared so far, |
| * a new sh_info is created. The new address space area simply gets the |
| * sh_info of the source area. The process of duplicating the |
| * mapping is done through the backend share function. |
| * |
| * @param src_as Pointer to source address space. |
| * @param src_base Base address of the source address space area. |
| * @param acc_size Expected size of the source area. |
| * @param dst_as Pointer to destination address space. |
| * @param dst_base Target base address. |
| * @param dst_flags_mask Destination address space area flags mask. |
| * |
| * @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. ENOTSUP is returned if an attempt |
| * to share non-anonymous address space area is detected. |
| */ |
| int as_area_share(as_t *src_as, uintptr_t src_base, size_t acc_size, |
| as_t *dst_as, uintptr_t dst_base, int dst_flags_mask) |
| { |
| ipl_t ipl; |
| int src_flags; |
| size_t src_size; |
| as_area_t *src_area, *dst_area; |
| share_info_t *sh_info; |
| mem_backend_t *src_backend; |
| mem_backend_data_t src_backend_data; |
| |
| ipl = interrupts_disable(); |
| mutex_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. |
| */ |
| mutex_unlock(&src_as->lock); |
| interrupts_restore(ipl); |
| return ENOENT; |
| } |
| |
| if (!src_area->backend || !src_area->backend->share) { |
| /* |
| * There is now backend or the backend does not |
| * know how to share the area. |
| */ |
| mutex_unlock(&src_area->lock); |
| mutex_unlock(&src_as->lock); |
| interrupts_restore(ipl); |
| return ENOTSUP; |
| } |
| |
| src_size = src_area->pages * PAGE_SIZE; |
| src_flags = src_area->flags; |
| src_backend = src_area->backend; |
| src_backend_data = src_area->backend_data; |
| |
| /* Share the cacheable flag from the original mapping */ |
| if (src_flags & AS_AREA_CACHEABLE) |
| dst_flags_mask |= AS_AREA_CACHEABLE; |
| |
| if (src_size != acc_size || (src_flags & dst_flags_mask) != dst_flags_mask) { |
| mutex_unlock(&src_area->lock); |
| mutex_unlock(&src_as->lock); |
| interrupts_restore(ipl); |
| return EPERM; |
| } |
| |
| /* |
| * Now we are committed to sharing the area. |
| * First prepare the area for sharing. |
| * Then it will be safe to unlock it. |
| */ |
| sh_info = src_area->sh_info; |
| if (!sh_info) { |
| sh_info = (share_info_t *) malloc(sizeof(share_info_t), 0); |
| mutex_initialize(&sh_info->lock); |
| sh_info->refcount = 2; |
| btree_create(&sh_info->pagemap); |
| src_area->sh_info = sh_info; |
| } else { |
| mutex_lock(&sh_info->lock); |
| sh_info->refcount++; |
| mutex_unlock(&sh_info->lock); |
| } |
| |
| src_area->backend->share(src_area); |
| |
| mutex_unlock(&src_area->lock); |
| mutex_unlock(&src_as->lock); |
| |
| /* |
| * 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. |
| * The flags of the source area are masked against dst_flags_mask |
| * to support sharing in less privileged mode. |
| */ |
| dst_area = as_area_create(dst_as, dst_flags_mask, src_size, dst_base, |
| AS_AREA_ATTR_PARTIAL, src_backend, &src_backend_data); |
| if (!dst_area) { |
| /* |
| * Destination address space area could not be created. |
| */ |
| sh_info_remove_reference(sh_info); |
| |
| interrupts_restore(ipl); |
| return ENOMEM; |
| } |
| |
| /* |
| * Now the destination address space area has been |
| * fully initialized. Clear the AS_AREA_ATTR_PARTIAL |
| * attribute and set the sh_info. |
| */ |
| mutex_lock(&dst_area->lock); |
| dst_area->attributes &= ~AS_AREA_ATTR_PARTIAL; |
| dst_area->sh_info = sh_info; |
| mutex_unlock(&dst_area->lock); |
| |
| interrupts_restore(ipl); |
| |
| return 0; |
| } |
| |
| /** Check access mode for address space area. |
| * |
| * The address space area must be locked prior to this call. |
| * |
| * @param area Address space area. |
| * @param access Access mode. |
| * |
| * @return False if access violates area's permissions, true otherwise. |
| */ |
| bool as_area_check_access(as_area_t *area, pf_access_t access) |
| { |
| int flagmap[] = { |
| [PF_ACCESS_READ] = AS_AREA_READ, |
| [PF_ACCESS_WRITE] = AS_AREA_WRITE, |
| [PF_ACCESS_EXEC] = AS_AREA_EXEC |
| }; |
| |
| if (!(area->flags & flagmap[access])) |
| return false; |
| |
| return true; |
| } |
| |
| /** Handle page fault within the current address space. |
| * |
| * This is the high-level page fault handler. It decides |
| * whether the page fault can be resolved by any backend |
| * and if so, it invokes the backend to resolve the page |
| * fault. |
| * |
| * Interrupts are assumed disabled. |
| * |
| * @param page Faulting page. |
| * @param access Access mode that caused the fault (i.e. read/write/exec). |
| * @param istate Pointer to interrupted state. |
| * |
| * @return AS_PF_FAULT on page fault, AS_PF_OK on success or AS_PF_DEFER if the |
| * fault was caused by copy_to_uspace() or copy_from_uspace(). |
| */ |
| int as_page_fault(uintptr_t page, pf_access_t access, istate_t *istate) |
| { |
| pte_t *pte; |
| as_area_t *area; |
| |
| if (!THREAD) |
| return AS_PF_FAULT; |
| |
| ASSERT(AS); |
| |
| mutex_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. |
| */ |
| mutex_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. |
| */ |
| mutex_unlock(&area->lock); |
| mutex_unlock(&AS->lock); |
| goto page_fault; |
| } |
| |
| if (!area->backend || !area->backend->page_fault) { |
| /* |
| * The address space area is not backed by any backend |
| * or the backend cannot handle page faults. |
| */ |
| mutex_unlock(&area->lock); |
| mutex_unlock(&AS->lock); |
| goto page_fault; |
| } |
| |
| 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)) { |
| if (((access == PF_ACCESS_READ) && PTE_READABLE(pte)) || |
| (access == PF_ACCESS_WRITE && PTE_WRITABLE(pte)) || |
| (access == PF_ACCESS_EXEC && PTE_EXECUTABLE(pte))) { |
| page_table_unlock(AS, false); |
| mutex_unlock(&area->lock); |
| mutex_unlock(&AS->lock); |
| return AS_PF_OK; |
| } |
| } |
| } |
| |
| /* |
| * Resort to the backend page fault handler. |
| */ |
| if (area->backend->page_fault(area, page, access) != AS_PF_OK) { |
| page_table_unlock(AS, false); |
| mutex_unlock(&area->lock); |
| mutex_unlock(&AS->lock); |
| goto page_fault; |
| } |
| |
| page_table_unlock(AS, false); |
| mutex_unlock(&area->lock); |
| mutex_unlock(&AS->lock); |
| return AS_PF_OK; |
| |
| page_fault: |
| if (THREAD->in_copy_from_uspace) { |
| THREAD->in_copy_from_uspace = false; |
| istate_set_retaddr(istate, (uintptr_t) &memcpy_from_uspace_failover_address); |
| } else if (THREAD->in_copy_to_uspace) { |
| THREAD->in_copy_to_uspace = false; |
| istate_set_retaddr(istate, (uintptr_t) &memcpy_to_uspace_failover_address); |
| } else { |
| return AS_PF_FAULT; |
| } |
| |
| return AS_PF_DEFER; |
| } |
| |
| /** Switch address spaces. |
| * |
| * Note that this function cannot sleep as it is essentially a part of |
| * scheduling. Sleeping here would lead to deadlock on wakeup. |
| * |
| * @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(&inactive_as_with_asid_lock); |
| |
| /* |
| * First, take care of the old address space. |
| */ |
| if (old) { |
| mutex_lock_active(&old->lock); |
| ASSERT(old->cpu_refcount); |
| if((--old->cpu_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); |
| } |
| mutex_unlock(&old->lock); |
| } |
| |
| /* |
| * Second, prepare the new address space. |
| */ |
| mutex_lock_active(&new->lock); |
| if ((new->cpu_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); |
| mutex_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(); |
| mutex_lock_active(&new->lock); |
| new->asid = asid; |
| mutex_unlock(&new->lock); |
| } |
| spinlock_unlock(&inactive_as_with_asid_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_CACHEABLE) |
| 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 as_area_get_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); |
| } |
| |
| /** Destroy page table. |
| * |
| * Destroy page table in architecture specific way. |
| * |
| * @param page_table Physical address of PTL0. |
| */ |
| void page_table_destroy(pte_t *page_table) |
| { |
| ASSERT(as_operations); |
| ASSERT(as_operations->page_table_destroy); |
| |
| as_operations->page_table_destroy(page_table); |
| } |
| |
| /** 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, uintptr_t 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 */ |
| mutex_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]; |
| mutex_lock(&a->lock); |
| if ((a->base <= va) && (va < a->base + a->pages * PAGE_SIZE)) { |
| return a; |
| } |
| mutex_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]; |
| mutex_lock(&a->lock); |
| if (va < a->base + a->pages * PAGE_SIZE) { |
| return a; |
| } |
| mutex_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, uintptr_t 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]; |
| mutex_lock(&a->lock); |
| if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) { |
| mutex_unlock(&a->lock); |
| return false; |
| } |
| mutex_unlock(&a->lock); |
| } |
| if ((node = btree_leaf_node_right_neighbour(&as->as_area_btree, leaf))) { |
| a = (as_area_t *) node->value[0]; |
| mutex_lock(&a->lock); |
| if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) { |
| mutex_unlock(&a->lock); |
| return false; |
| } |
| mutex_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; |
| |
| mutex_lock(&a->lock); |
| if (overlaps(va, size, a->base, a->pages * PAGE_SIZE)) { |
| mutex_unlock(&a->lock); |
| return false; |
| } |
| mutex_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 the address space area with given base. */ |
| size_t as_get_size(uintptr_t 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; |
| mutex_unlock(&src_area->lock); |
| } else { |
| size = 0; |
| } |
| interrupts_restore(ipl); |
| return size; |
| } |
| |
| /** Mark portion of address space area as used. |
| * |
| * The address space area must be already locked. |
| * |
| * @param a Address space area. |
| * @param page First page to be marked. |
| * @param count Number of page to be marked. |
| * |
| * @return 0 on failure and 1 on success. |
| */ |
| int used_space_insert(as_area_t *a, uintptr_t page, count_t count) |
| { |
| btree_node_t *leaf, *node; |
| count_t pages; |
| int i; |
| |
| ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE)); |
| ASSERT(count); |
| |
| pages = (count_t) btree_search(&a->used_space, page, &leaf); |
| if (pages) { |
| /* |
| * We hit the beginning of some used space. |
| */ |
| return 0; |
| } |
| |
| if (!leaf->keys) { |
| btree_insert(&a->used_space, page, (void *) count, leaf); |
| return 1; |
| } |
| |
| node = btree_leaf_node_left_neighbour(&a->used_space, leaf); |
| if (node) { |
| uintptr_t left_pg = node->key[node->keys - 1], right_pg = leaf->key[0]; |
| count_t left_cnt = (count_t) node->value[node->keys - 1], right_cnt = (count_t) leaf->value[0]; |
| |
| /* |
| * Examine the possibility that the interval fits |
| * somewhere between the rightmost interval of |
| * the left neigbour and the first interval of the leaf. |
| */ |
| |
| if (page >= right_pg) { |
| /* Do nothing. */ |
| } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the left interval. */ |
| return 0; |
| } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the right interval. */ |
| return 0; |
| } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) { |
| /* The interval can be added by merging the two already present intervals. */ |
| node->value[node->keys - 1] += count + right_cnt; |
| btree_remove(&a->used_space, right_pg, leaf); |
| return 1; |
| } else if (page == left_pg + left_cnt*PAGE_SIZE) { |
| /* The interval can be added by simply growing the left interval. */ |
| node->value[node->keys - 1] += count; |
| return 1; |
| } else if (page + count*PAGE_SIZE == right_pg) { |
| /* |
| * The interval can be addded by simply moving base of the right |
| * interval down and increasing its size accordingly. |
| */ |
| leaf->value[0] += count; |
| leaf->key[0] = page; |
| return 1; |
| } else { |
| /* |
| * The interval is between both neigbouring intervals, |
| * but cannot be merged with any of them. |
| */ |
| btree_insert(&a->used_space, page, (void *) count, leaf); |
| return 1; |
| } |
| } else if (page < leaf->key[0]) { |
| uintptr_t right_pg = leaf->key[0]; |
| count_t right_cnt = (count_t) leaf->value[0]; |
| |
| /* |
| * Investigate the border case in which the left neighbour does not |
| * exist but the interval fits from the left. |
| */ |
| |
| if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the right interval. */ |
| return 0; |
| } else if (page + count*PAGE_SIZE == right_pg) { |
| /* |
| * The interval can be added by moving the base of the right interval down |
| * and increasing its size accordingly. |
| */ |
| leaf->key[0] = page; |
| leaf->value[0] += count; |
| return 1; |
| } else { |
| /* |
| * The interval doesn't adjoin with the right interval. |
| * It must be added individually. |
| */ |
| btree_insert(&a->used_space, page, (void *) count, leaf); |
| return 1; |
| } |
| } |
| |
| node = btree_leaf_node_right_neighbour(&a->used_space, leaf); |
| if (node) { |
| uintptr_t left_pg = leaf->key[leaf->keys - 1], right_pg = node->key[0]; |
| count_t left_cnt = (count_t) leaf->value[leaf->keys - 1], right_cnt = (count_t) node->value[0]; |
| |
| /* |
| * Examine the possibility that the interval fits |
| * somewhere between the leftmost interval of |
| * the right neigbour and the last interval of the leaf. |
| */ |
| |
| if (page < left_pg) { |
| /* Do nothing. */ |
| } else if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the left interval. */ |
| return 0; |
| } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the right interval. */ |
| return 0; |
| } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) { |
| /* The interval can be added by merging the two already present intervals. */ |
| leaf->value[leaf->keys - 1] += count + right_cnt; |
| btree_remove(&a->used_space, right_pg, node); |
| return 1; |
| } else if (page == left_pg + left_cnt*PAGE_SIZE) { |
| /* The interval can be added by simply growing the left interval. */ |
| leaf->value[leaf->keys - 1] += count; |
| return 1; |
| } else if (page + count*PAGE_SIZE == right_pg) { |
| /* |
| * The interval can be addded by simply moving base of the right |
| * interval down and increasing its size accordingly. |
| */ |
| node->value[0] += count; |
| node->key[0] = page; |
| return 1; |
| } else { |
| /* |
| * The interval is between both neigbouring intervals, |
| * but cannot be merged with any of them. |
| */ |
| btree_insert(&a->used_space, page, (void *) count, leaf); |
| return 1; |
| } |
| } else if (page >= leaf->key[leaf->keys - 1]) { |
| uintptr_t left_pg = leaf->key[leaf->keys - 1]; |
| count_t left_cnt = (count_t) leaf->value[leaf->keys - 1]; |
| |
| /* |
| * Investigate the border case in which the right neighbour does not |
| * exist but the interval fits from the right. |
| */ |
| |
| if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the left interval. */ |
| return 0; |
| } else if (left_pg + left_cnt*PAGE_SIZE == page) { |
| /* The interval can be added by growing the left interval. */ |
| leaf->value[leaf->keys - 1] += count; |
| return 1; |
| } else { |
| /* |
| * The interval doesn't adjoin with the left interval. |
| * It must be added individually. |
| */ |
| btree_insert(&a->used_space, page, (void *) count, leaf); |
| return 1; |
| } |
| } |
| |
| /* |
| * Note that if the algorithm made it thus far, the interval can fit only |
| * between two other intervals of the leaf. The two border cases were already |
| * resolved. |
| */ |
| for (i = 1; i < leaf->keys; i++) { |
| if (page < leaf->key[i]) { |
| uintptr_t left_pg = leaf->key[i - 1], right_pg = leaf->key[i]; |
| count_t left_cnt = (count_t) leaf->value[i - 1], right_cnt = (count_t) leaf->value[i]; |
| |
| /* |
| * The interval fits between left_pg and right_pg. |
| */ |
| |
| if (overlaps(page, count*PAGE_SIZE, left_pg, left_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the left interval. */ |
| return 0; |
| } else if (overlaps(page, count*PAGE_SIZE, right_pg, right_cnt*PAGE_SIZE)) { |
| /* The interval intersects with the right interval. */ |
| return 0; |
| } else if ((page == left_pg + left_cnt*PAGE_SIZE) && (page + count*PAGE_SIZE == right_pg)) { |
| /* The interval can be added by merging the two already present intervals. */ |
| leaf->value[i - 1] += count + right_cnt; |
| btree_remove(&a->used_space, right_pg, leaf); |
| return 1; |
| } else if (page == left_pg + left_cnt*PAGE_SIZE) { |
| /* The interval can be added by simply growing the left interval. */ |
| leaf->value[i - 1] += count; |
| return 1; |
| } else if (page + count*PAGE_SIZE == right_pg) { |
| /* |
| * The interval can be addded by simply moving base of the right |
| * interval down and increasing its size accordingly. |
| */ |
| leaf->value[i] += count; |
| leaf->key[i] = page; |
| return 1; |
| } else { |
| /* |
| * The interval is between both neigbouring intervals, |
| * but cannot be merged with any of them. |
| */ |
| btree_insert(&a->used_space, page, (void *) count, leaf); |
| return 1; |
| } |
| } |
| } |
| |
| panic("Inconsistency detected while adding %d pages of used space at %p.\n", count, page); |
| } |
| |
| /** Mark portion of address space area as unused. |
| * |
| * The address space area must be already locked. |
| * |
| * @param a Address space area. |
| * @param page First page to be marked. |
| * @param count Number of page to be marked. |
| * |
| * @return 0 on failure and 1 on success. |
| */ |
| int used_space_remove(as_area_t *a, uintptr_t page, count_t count) |
| { |
| btree_node_t *leaf, *node; |
| count_t pages; |
| int i; |
| |
| ASSERT(page == ALIGN_DOWN(page, PAGE_SIZE)); |
| ASSERT(count); |
| |
| pages = (count_t) btree_search(&a->used_space, page, &leaf); |
| if (pages) { |
| /* |
| * We are lucky, page is the beginning of some interval. |
| */ |
| if (count > pages) { |
| return 0; |
| } else if (count == pages) { |
| btree_remove(&a->used_space, page, leaf); |
| return 1; |
| } else { |
| /* |
| * Find the respective interval. |
| * Decrease its size and relocate its start address. |
| */ |
| for (i = 0; i < leaf->keys; i++) { |
| if (leaf->key[i] == page) { |
| leaf->key[i] += count*PAGE_SIZE; |
| leaf->value[i] -= count; |
| return 1; |
| } |
| } |
| goto error; |
| } |
| } |
| |
| node = btree_leaf_node_left_neighbour(&a->used_space, leaf); |
| if (node && page < leaf->key[0]) { |
| uintptr_t left_pg = node->key[node->keys - 1]; |
| count_t left_cnt = (count_t) node->value[node->keys - 1]; |
| |
| if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) { |
| if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) { |
| /* |
| * The interval is contained in the rightmost interval |
| * of the left neighbour and can be removed by |
| * updating the size of the bigger interval. |
| */ |
| node->value[node->keys - 1] -= count; |
| return 1; |
| } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) { |
| count_t new_cnt; |
| |
| /* |
| * The interval is contained in the rightmost interval |
| * of the left neighbour but its removal requires |
| * both updating the size of the original interval and |
| * also inserting a new interval. |
| */ |
| new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH; |
| node->value[node->keys - 1] -= count + new_cnt; |
| btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf); |
| return 1; |
| } |
| } |
| return 0; |
| } else if (page < leaf->key[0]) { |
| return 0; |
| } |
| |
| if (page > leaf->key[leaf->keys - 1]) { |
| uintptr_t left_pg = leaf->key[leaf->keys - 1]; |
| count_t left_cnt = (count_t) leaf->value[leaf->keys - 1]; |
| |
| if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) { |
| if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) { |
| /* |
| * The interval is contained in the rightmost interval |
| * of the leaf and can be removed by updating the size |
| * of the bigger interval. |
| */ |
| leaf->value[leaf->keys - 1] -= count; |
| return 1; |
| } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) { |
| count_t new_cnt; |
| |
| /* |
| * The interval is contained in the rightmost interval |
| * of the leaf but its removal requires both updating |
| * the size of the original interval and |
| * also inserting a new interval. |
| */ |
| new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH; |
| leaf->value[leaf->keys - 1] -= count + new_cnt; |
| btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf); |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * The border cases have been already resolved. |
| * Now the interval can be only between intervals of the leaf. |
| */ |
| for (i = 1; i < leaf->keys - 1; i++) { |
| if (page < leaf->key[i]) { |
| uintptr_t left_pg = leaf->key[i - 1]; |
| count_t left_cnt = (count_t) leaf->value[i - 1]; |
| |
| /* |
| * Now the interval is between intervals corresponding to (i - 1) and i. |
| */ |
| if (overlaps(left_pg, left_cnt*PAGE_SIZE, page, count*PAGE_SIZE)) { |
| if (page + count*PAGE_SIZE == left_pg + left_cnt*PAGE_SIZE) { |
| /* |
| * The interval is contained in the interval (i - 1) |
| * of the leaf and can be removed by updating the size |
| * of the bigger interval. |
| */ |
| leaf->value[i - 1] -= count; |
| return 1; |
| } else if (page + count*PAGE_SIZE < left_pg + left_cnt*PAGE_SIZE) { |
| count_t new_cnt; |
| |
| /* |
| * The interval is contained in the interval (i - 1) |
| * of the leaf but its removal requires both updating |
| * the size of the original interval and |
| * also inserting a new interval. |
| */ |
| new_cnt = ((left_pg + left_cnt*PAGE_SIZE) - (page + count*PAGE_SIZE)) >> PAGE_WIDTH; |
| leaf->value[i - 1] -= count + new_cnt; |
| btree_insert(&a->used_space, page + count*PAGE_SIZE, (void *) new_cnt, leaf); |
| return 1; |
| } |
| } |
| return 0; |
| } |
| } |
| |
| error: |
| panic("Inconsistency detected while removing %d pages of used space from %p.\n", count, page); |
| } |
| |
| /** Remove reference to address space area share info. |
| * |
| * If the reference count drops to 0, the sh_info is deallocated. |
| * |
| * @param sh_info Pointer to address space area share info. |
| */ |
| void sh_info_remove_reference(share_info_t *sh_info) |
| { |
| bool dealloc = false; |
| |
| mutex_lock(&sh_info->lock); |
| ASSERT(sh_info->refcount); |
| if (--sh_info->refcount == 0) { |
| dealloc = true; |
| link_t *cur; |
| |
| /* |
| * Now walk carefully the pagemap B+tree and free/remove |
| * reference from all frames found there. |
| */ |
| for (cur = sh_info->pagemap.leaf_head.next; cur != &sh_info->pagemap.leaf_head; cur = cur->next) { |
| btree_node_t *node; |
| int i; |
| |
| node = list_get_instance(cur, btree_node_t, leaf_link); |
| for (i = 0; i < node->keys; i++) |
| frame_free((uintptr_t) node->value[i]); |
| } |
| |
| } |
| mutex_unlock(&sh_info->lock); |
| |
| if (dealloc) { |
| btree_destroy(&sh_info->pagemap); |
| free(sh_info); |
| } |
| } |
| |
| /* |
| * Address space related syscalls. |
| */ |
| |
| /** Wrapper for as_area_create(). */ |
| unative_t sys_as_area_create(uintptr_t address, size_t size, int flags) |
| { |
| if (as_area_create(AS, flags | AS_AREA_CACHEABLE, size, address, AS_AREA_ATTR_NONE, &anon_backend, NULL)) |
| return (unative_t) address; |
| else |
| return (unative_t) -1; |
| } |
| |
| /** Wrapper for as_area_resize. */ |
| unative_t sys_as_area_resize(uintptr_t address, size_t size, int flags) |
| { |
| return (unative_t) as_area_resize(AS, address, size, 0); |
| } |
| |
| /** Wrapper for as_area_destroy. */ |
| unative_t sys_as_area_destroy(uintptr_t address) |
| { |
| return (unative_t) as_area_destroy(AS, address); |
| } |
| |
| /** @} |
| */ |