This reverts commit 0115f6cbf26663c86496bc56eeea293f85b77897.
The problem fixed in 0115f6cbf26663c86496bc56eeea293f85b77897 is that
it is expected to replace a base page mapping entry in FTLB with a
huge page mapping entry using tlbwi, but doing it is not permitted by
hardware.
The same problem is hit by __update_tlb from do_page_fault first, but it
DOES NOT work it out, and cause another TLB Invalid and give
0115f6cbf26663c86496bc56eeea293f85b77897 the chane to fix it. Let
__update_tlb fix it and remove this extra TLB Invalid exception.
Move the fix from handle_tlb[lms] to __update_tlb, and now huge page
fault path only take 1 TLB Miss plus 1 TLB Invalid, instead of 1 TLB Miss
plus 2 TLB Invalid
Whether fixed by 0115f6cbf26663c86496bc56eeea293f85b77897 or by __update_tlb,
the root cause is TLB Miss handler writes invalid mapping entry into TLB
without checking _PAGE_PRESENT, and this can not be fixed unless letting
CP0 Entrylo0 & Entrylo1 map one page instead of two, like mapping Huge Page
Signed-off-by: Huang Pei <huangpei@xxxxxxxxxxx>
---
arch/mips/mm/tlb-r4k.c | 15 ++++++++++++++-
arch/mips/mm/tlbex.c | 25 ++++---------------------
2 files changed, 18 insertions(+), 22 deletions(-)
diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
index 38e2894d5fa3..cb8afa326b2c 100644
--- a/arch/mips/mm/tlb-r4k.c
+++ b/arch/mips/mm/tlb-r4k.c
@@ -328,6 +328,7 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
/* this could be a huge page */
if (pmd_huge(*pmdp)) {
unsigned long lo;
+ unsigned long entryhi;
write_c0_pagemask(PM_HUGE_MASK);
ptep = (pte_t *)pmdp;
lo = pte_to_entrylo(pte_val(*ptep));
@@ -335,7 +336,19 @@ void __update_tlb(struct vm_area_struct * vma, unsigned long address, pte_t pte)
write_c0_entrylo1(lo + (HPAGE_SIZE >> 7));
mtc0_tlbw_hazard();
- if (idx < 0)
+ if (idx >= current_cpu_data.tlbsizevtlb) {
+ /* hit in FTLB.
+ * Invalid it then tlbwr, since FTLB hold only base page*/
+ entryhi = read_c0_entryhi();
+ write_c0_entryhi(MIPS_ENTRYHI_EHINV);
+ tlb_write_indexed();
+ tlbw_use_hazard();
+ write_c0_entryhi(entryhi);
+
+ }
+
+
+ if (idx < 0 || idx >= current_cpu_data.tlbsizevtlb)
tlb_write_random();
else
tlb_write_indexed();
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 14f8ba93367f..9c4cd08c00d3 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -762,8 +762,7 @@ static void build_huge_update_entries(u32 **p, unsigned int pte,
static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r,
struct uasm_label **l,
unsigned int pte,
- unsigned int ptr,
- unsigned int flush)
+ unsigned int ptr)
{
#ifdef CONFIG_SMP
UASM_i_SC(p, pte, 0, ptr);
@@ -772,22 +771,6 @@ static void build_huge_handler_tail(u32 **p, struct uasm_reloc **r,
#else
UASM_i_SW(p, pte, 0, ptr);
#endif
- if (cpu_has_ftlb && flush) {
- BUG_ON(!cpu_has_tlbinv);
-
- UASM_i_MFC0(p, ptr, C0_ENTRYHI);
- uasm_i_ori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
- UASM_i_MTC0(p, ptr, C0_ENTRYHI);
- build_tlb_write_entry(p, l, r, tlb_indexed);
-
- uasm_i_xori(p, ptr, ptr, MIPS_ENTRYHI_EHINV);
- UASM_i_MTC0(p, ptr, C0_ENTRYHI);
- build_huge_update_entries(p, pte, ptr);
- build_huge_tlb_write_entry(p, l, r, pte, tlb_random, 0);
-
- return;
- }
-
build_huge_update_entries(p, pte, ptr);
build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
}
@@ -2278,7 +2261,7 @@ static void build_r4000_tlb_load_handler(void)
uasm_l_tlbl_goaround2(&l, p);
}
uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID));
- build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
+ build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
#endif
uasm_l_nopage_tlbl(&l, p);
@@ -2334,7 +2317,7 @@ static void build_r4000_tlb_store_handler(void)
build_tlb_probe_entry(&p);
uasm_i_ori(&p, wr.r1, wr.r1,
_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
- build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1);
+ build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
#endif
uasm_l_nopage_tlbs(&l, p);
@@ -2391,7 +2374,7 @@ static void build_r4000_tlb_modify_handler(void)
build_tlb_probe_entry(&p);
uasm_i_ori(&p, wr.r1, wr.r1,
_PAGE_ACCESSED | _PAGE_MODIFIED | _PAGE_VALID | _PAGE_DIRTY);
- build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 0);
+ build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2);
#endif
uasm_l_nopage_tlbm(&l, p);
--
2.17.1
