/*
* Copyright (C) 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.
*/
/*
* TLB management.
*/
#include <mm/tlb.h>
#include <mm/asid.h>
#include <mm/page.h>
#include <mm/as.h>
#include <arch/mm/tlb.h>
#include <arch/mm/page.h>
#include <arch/barrier.h>
#include <arch/interrupt.h>
#include <typedefs.h>
#include <panic.h>
#include <arch.h>
/** Invalidate all TLB entries. */
void tlb_invalidate_all(void)
{
/* TODO */
}
/** Invalidate entries belonging to an address space.
*
* @param asid Address space identifier.
*/
void tlb_invalidate_asid(asid_t asid)
{
/* TODO */
}
/** Insert data into data translation cache.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
*/
void dtc_mapping_insert(__address va, asid_t asid, tlb_entry_t entry)
{
tc_mapping_insert(va, asid, entry, true);
}
/** Insert data into instruction translation cache.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
*/
void itc_mapping_insert(__address va, asid_t asid, tlb_entry_t entry)
{
tc_mapping_insert(va, asid, entry, false);
}
/** Insert data into instruction or data translation cache.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
* @param dtc If true, insert into data translation cache, use instruction translation cache otherwise.
*/
void tc_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, bool dtc)
{
region_register rr;
bool restore_rr = false;
rr.word = rr_read(VA2VRN(va));
if ((restore_rr = (rr.map.rid != ASID2RID(asid, VA2VRN(va))))) {
/*
* The selected region register does not contain required RID.
* Save the old content of the register and replace the RID.
*/
region_register rr0;
rr0 = rr;
rr0.map.rid = ASID2RID(asid, VA2VRN(va));
rr_write(VA2VRN(va), rr0.word);
srlz_d();
srlz_i();
}
__asm__ volatile (
"mov r8=psr;;\n"
"rsm %0;;\n" /* PSR_IC_MASK */
"srlz.d;;\n"
"srlz.i;;\n"
"mov cr.ifa=%1\n" /* va */
"mov cr.itir=%2;;\n" /* entry.word[1] */
"cmp.eq p6,p7 = %4,r0;;\n" /* decide between itc and dtc */
"(p6) itc.i %3;;\n"
"(p7) itc.d %3;;\n"
"mov psr.l=r8;;\n"
"srlz.d;;\n"
:
: "i" (PSR_IC_MASK), "r" (va), "r" (entry.word[1]), "r" (entry.word[0]), "r" (dtc)
: "p6", "p7", "r8"
);
if (restore_rr) {
rr_write(VA2VRN(va), rr.word);
srlz_d();
srlz_i();
}
}
/** Insert data into instruction translation register.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
* @param tr Translation register.
*/
void itr_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, index_t tr)
{
tr_mapping_insert(va, asid, entry, false, tr);
}
/** Insert data into data translation register.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
* @param tr Translation register.
*/
void dtr_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, index_t tr)
{
tr_mapping_insert(va, asid, entry, true, tr);
}
/** Insert data into instruction or data translation register.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
* @param dtc If true, insert into data translation register, use instruction translation register otherwise.
* @param tr Translation register.
*/
void tr_mapping_insert(__address va, asid_t asid, tlb_entry_t entry, bool dtr, index_t tr)
{
region_register rr;
bool restore_rr = false;
rr.word = rr_read(VA2VRN(va));
if ((restore_rr = (rr.map.rid != ASID2RID(asid, VA2VRN(va))))) {
/*
* The selected region register does not contain required RID.
* Save the old content of the register and replace the RID.
*/
region_register rr0;
rr0 = rr;
rr0.map.rid = ASID2RID(asid, VA2VRN(va));
rr_write(VA2VRN(va), rr0.word);
srlz_d();
srlz_i();
}
__asm__ volatile (
"mov r8=psr;;\n"
"rsm %0;;\n" /* PSR_IC_MASK */
"srlz.d;;\n"
"srlz.i;;\n"
"mov cr.ifa=%1\n" /* va */
"mov cr.itir=%2;;\n" /* entry.word[1] */
"cmp.eq p6,p7=%5,r0;;\n" /* decide between itr and dtr */
"(p6) itr.i itr[%4]=%3;;\n"
"(p7) itr.d dtr[%4]=%3;;\n"
"mov psr.l=r8;;\n"
"srlz.d;;\n"
:
: "i" (PSR_IC_MASK), "r" (va), "r" (entry.word[1]), "r" (entry.word[0]), "r" (tr), "r" (dtr)
: "p6", "p7", "r8"
);
if (restore_rr) {
rr_write(VA2VRN(va), rr.word);
srlz_d();
srlz_i();
}
}
/** Insert data into DTLB.
*
* @param va Virtual page address.
* @param asid Address space identifier.
* @param entry The rest of TLB entry as required by TLB insertion format.
* @param dtr If true, insert into data translation register, use data translation cache otherwise.
* @param tr Translation register if dtr is true, ignored otherwise.
*/
void dtlb_kernel_mapping_insert(__address page, __address frame, bool dtr, index_t tr)
{
tlb_entry_t entry;
entry.word[0] = 0;
entry.word[1] = 0;
entry.p = true; /* present */
entry.ma = MA_WRITEBACK;
entry.a = true; /* already accessed */
entry.d = true; /* already dirty */
entry.pl = PL_KERNEL;
entry.ar = AR_READ | AR_WRITE;
entry.ppn = frame >> PPN_SHIFT;
entry.ps = PAGE_WIDTH;
if (dtr)
dtr_mapping_insert(page, ASID_KERNEL, entry, tr);
else
dtc_mapping_insert(page, ASID_KERNEL, entry);
}
/** Copy content of PTE into data translation cache.
*
* @param t PTE.
*/
void dtc_pte_copy(pte_t *t)
{
tlb_entry_t entry;
entry.word[0] = 0;
entry.word[1] = 0;
entry.p = t->p;
entry.ma = t->c ? MA_WRITEBACK : MA_UNCACHEABLE;
entry.a = t->a;
entry.d = t->d;
entry.pl = t->k ? PL_KERNEL : PL_USER;
entry.ar = t->w ? AR_WRITE : AR_READ;
entry.ppn = t->frame >> PPN_SHIFT;
entry.ps = PAGE_WIDTH;
dtc_mapping_insert(t->page, t->as->asid, entry);
}
/** Copy content of PTE into instruction translation cache.
*
* @param t PTE.
*/
void itc_pte_copy(pte_t *t)
{
tlb_entry_t entry;
entry.word[0] = 0;
entry.word[1] = 0;
ASSERT(t->x);
entry.p = t->p;
entry.ma = t->c ? MA_WRITEBACK : MA_UNCACHEABLE;
entry.a = t->a;
entry.pl = t->k ? PL_KERNEL : PL_USER;
entry.ar = t->x ? (AR_EXECUTE | AR_READ) : AR_READ;
entry.ppn = t->frame >> PPN_SHIFT;
entry.ps = PAGE_WIDTH;
itc_mapping_insert(t->page, t->as->asid, entry);
}
/** Instruction TLB fault handler for faults with VHPT turned off.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void alternate_instruction_tlb_fault(__u64 vector, struct exception_regdump *pstate)
{
region_register rr;
__address va;
pte_t *t;
va = pstate->cr_ifa; /* faulting address */
t = page_mapping_find(AS, va);
if (t) {
/*
* The mapping was found in software page hash table.
* Insert it into data translation cache.
*/
itc_pte_copy(t);
} else {
/*
* Forward the page fault to address space page fault handler.
*/
if (!as_page_fault(va)) {
panic("%s: va=%P, rid=%d\n", __FUNCTION__, pstate->cr_ifa, rr.map.rid);
}
}
}
/** Data TLB fault handler for faults with VHPT turned off.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void alternate_data_tlb_fault(__u64 vector, struct exception_regdump *pstate)
{
region_register rr;
rid_t rid;
__address va;
pte_t *t;
va = pstate->cr_ifa; /* faulting address */
rr.word = rr_read(VA2VRN(va));
rid = rr.map.rid;
if (RID2ASID(rid) == ASID_KERNEL) {
if (VA2VRN(va) == VRN_KERNEL) {
/*
* Provide KA2PA(identity) mapping for faulting piece of
* kernel address space.
*/
dtlb_kernel_mapping_insert(va, KA2PA(va), false, 0);
return;
}
}
t = page_mapping_find(AS, va);
if (t) {
/*
* The mapping was found in software page hash table.
* Insert it into data translation cache.
*/
dtc_pte_copy(t);
} else {
/*
* Forward the page fault to address space page fault handler.
*/
if (!as_page_fault(va)) {
panic("%s: va=%P, rid=%d\n", __FUNCTION__, pstate->cr_ifa, rr.map.rid);
}
}
}
/** Data nested TLB fault handler.
*
* This fault should not occur.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void data_nested_tlb_fault(__u64 vector, struct exception_regdump *pstate)
{
panic("%s\n", __FUNCTION__);
}
/** Data Dirty bit fault handler.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void data_dirty_bit_fault(__u64 vector, struct exception_regdump *pstate)
{
pte_t *t;
t = page_mapping_find(AS, pstate->cr_ifa);
ASSERT(t && t->p);
if (t && t->p) {
/*
* Update the Dirty bit in page tables and reinsert
* the mapping into DTC.
*/
t->d = true;
dtc_pte_copy(t);
}
}
/** Instruction access bit fault handler.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void instruction_access_bit_fault(__u64 vector, struct exception_regdump *pstate)
{
pte_t *t;
t = page_mapping_find(AS, pstate->cr_ifa);
ASSERT(t && t->p);
if (t && t->p) {
/*
* Update the Accessed bit in page tables and reinsert
* the mapping into ITC.
*/
t->a = true;
itc_pte_copy(t);
}
}
/** Data access bit fault handler.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void data_access_bit_fault(__u64 vector, struct exception_regdump *pstate)
{
pte_t *t;
t = page_mapping_find(AS, pstate->cr_ifa);
ASSERT(t && t->p);
if (t && t->p) {
/*
* Update the Accessed bit in page tables and reinsert
* the mapping into DTC.
*/
t->a = true;
dtc_pte_copy(t);
}
}
/** Page not present fault handler.
*
* @param vector Interruption vector.
* @param pstate Structure with saved interruption state.
*/
void page_not_present(__u64 vector, struct exception_regdump *pstate)
{
region_register rr;
__address va;
pte_t *t;
va = pstate->cr_ifa; /* faulting address */
t = page_mapping_find(AS, va);
ASSERT(t);
if (t->p) {
/*
* If the Present bit is set in page hash table, just copy it
* and update ITC/DTC.
*/
if (t->x)
itc_pte_copy(t);
else
dtc_pte_copy(t);
} else {
if (!as_page_fault(va)) {
panic("%s: va=%P, rid=%d\n", __FUNCTION__, pstate->cr_ifa, rr.map.rid);
}
}
}