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authorHuacai Chen <chenhuacai@loongson.cn>2023-06-29 20:58:44 +0800
committerHuacai Chen <chenhuacai@loongson.cn>2023-06-29 20:58:44 +0800
commit01158487af60cd3915e8c31924144caf29cb0767 (patch)
tree01bdd88063128e646a6fdc394a9c2d8c7a138316 /arch/loongarch/mm
parente031a5f3f1eddb961a6ded8a21ab8189d8760860 (diff)
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LoongArch: Introduce hardware page table walker
Loongson-3A6000 and newer processors have hardware page table walker (PTW) support. PTW can handle all fastpaths of TLBI/TLBL/TLBS/TLBM exceptions by hardware, software only need to handle slowpaths (page faults). BTW, PTW doesn't append _PAGE_MODIFIED for page table entries, so we change pmd_dirty() and pte_dirty() to also check _PAGE_DIRTY for the "dirty" attribute. Signed-off-by: Liang Gao <gaoliang@loongson.cn> Signed-off-by: Jun Yi <yijun@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/mm')
-rw-r--r--arch/loongarch/mm/tlb.c21
-rw-r--r--arch/loongarch/mm/tlbex.S21
2 files changed, 38 insertions, 4 deletions
diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c
index 8bad6b0cff59..00bb563e3c89 100644
--- a/arch/loongarch/mm/tlb.c
+++ b/arch/loongarch/mm/tlb.c
@@ -167,6 +167,9 @@ void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep
int idx;
unsigned long flags;
+ if (cpu_has_ptw)
+ return;
+
/*
* Handle debugger faulting in for debugee.
*/
@@ -222,6 +225,9 @@ static void setup_ptwalker(void)
pwctl0 = pte_i | pte_w << 5 | pmd_i << 10 | pmd_w << 15 | pud_i << 20 | pud_w << 25;
pwctl1 = pgd_i | pgd_w << 6;
+ if (cpu_has_ptw)
+ pwctl1 |= CSR_PWCTL1_PTW;
+
csr_write64(pwctl0, LOONGARCH_CSR_PWCTL0);
csr_write64(pwctl1, LOONGARCH_CSR_PWCTL1);
csr_write64((long)swapper_pg_dir, LOONGARCH_CSR_PGDH);
@@ -264,10 +270,17 @@ void setup_tlb_handler(int cpu)
if (cpu == 0) {
memcpy((void *)tlbrentry, handle_tlb_refill, 0x80);
local_flush_icache_range(tlbrentry, tlbrentry + 0x80);
- set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
- set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE);
- set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE);
- set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE);
+ if (!cpu_has_ptw) {
+ set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load, VECSIZE);
+ set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load, VECSIZE);
+ set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store, VECSIZE);
+ set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify, VECSIZE);
+ } else {
+ set_handler(EXCCODE_TLBI * VECSIZE, handle_tlb_load_ptw, VECSIZE);
+ set_handler(EXCCODE_TLBL * VECSIZE, handle_tlb_load_ptw, VECSIZE);
+ set_handler(EXCCODE_TLBS * VECSIZE, handle_tlb_store_ptw, VECSIZE);
+ set_handler(EXCCODE_TLBM * VECSIZE, handle_tlb_modify_ptw, VECSIZE);
+ }
set_handler(EXCCODE_TLBNR * VECSIZE, handle_tlb_protect, VECSIZE);
set_handler(EXCCODE_TLBNX * VECSIZE, handle_tlb_protect, VECSIZE);
set_handler(EXCCODE_TLBPE * VECSIZE, handle_tlb_protect, VECSIZE);
diff --git a/arch/loongarch/mm/tlbex.S b/arch/loongarch/mm/tlbex.S
index 240ced55586e..4ad78703de6f 100644
--- a/arch/loongarch/mm/tlbex.S
+++ b/arch/loongarch/mm/tlbex.S
@@ -190,6 +190,13 @@ nopage_tlb_load:
jr t0
SYM_FUNC_END(handle_tlb_load)
+SYM_FUNC_START(handle_tlb_load_ptw)
+ csrwr t0, LOONGARCH_CSR_KS0
+ csrwr t1, LOONGARCH_CSR_KS1
+ la_abs t0, tlb_do_page_fault_0
+ jr t0
+SYM_FUNC_END(handle_tlb_load_ptw)
+
SYM_FUNC_START(handle_tlb_store)
csrwr t0, EXCEPTION_KS0
csrwr t1, EXCEPTION_KS1
@@ -339,6 +346,13 @@ nopage_tlb_store:
jr t0
SYM_FUNC_END(handle_tlb_store)
+SYM_FUNC_START(handle_tlb_store_ptw)
+ csrwr t0, LOONGARCH_CSR_KS0
+ csrwr t1, LOONGARCH_CSR_KS1
+ la_abs t0, tlb_do_page_fault_1
+ jr t0
+SYM_FUNC_END(handle_tlb_store_ptw)
+
SYM_FUNC_START(handle_tlb_modify)
csrwr t0, EXCEPTION_KS0
csrwr t1, EXCEPTION_KS1
@@ -486,6 +500,13 @@ nopage_tlb_modify:
jr t0
SYM_FUNC_END(handle_tlb_modify)
+SYM_FUNC_START(handle_tlb_modify_ptw)
+ csrwr t0, LOONGARCH_CSR_KS0
+ csrwr t1, LOONGARCH_CSR_KS1
+ la_abs t0, tlb_do_page_fault_1
+ jr t0
+SYM_FUNC_END(handle_tlb_modify_ptw)
+
SYM_FUNC_START(handle_tlb_refill)
csrwr t0, LOONGARCH_CSR_TLBRSAVE
csrrd t0, LOONGARCH_CSR_PGD