[PATCH v2 1/2] MIPS: Set page access bit with pgprot on platforms with RIXI
From: Bibo Mao
Date: Sat Jun 06 2020 - 00:04:16 EST
On MIPS system which has rixi hardware bit, page access bit is not
set in pgrot. For memory reading, there will be one page fault to
allocate physical page; however valid bit is not set, there will
be the second fast tlb-miss fault handling to set valid/access bit.
This patch set page access/valid bit with pgrot if there is reading
access privilege. It will reduce one tlb-miss handling for memory
reading access.
The valid/access bit will be cleared in order to track memory
accessing activity. If the page is accessed, tlb-miss fast handling
will set valid/access bit, pte_sw_mkyoung is not necessary in slow
page fault path. This patch removes pte_sw_mkyoung function which
is defined as empty function except MIPS system.
Signed-off-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Acked-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
v2:
- refine commit log title
---
arch/mips/include/asm/pgtable.h | 10 ++++++++--
arch/mips/mm/cache.c | 34 +++++++++++++++++-----------------
include/asm-generic/pgtable.h | 16 ----------------
mm/memory.c | 3 ---
4 files changed, 25 insertions(+), 38 deletions(-)
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 85b39c9..d066469 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -25,6 +25,14 @@
struct mm_struct;
struct vm_area_struct;
+#define __PP _PAGE_PRESENT
+#define __NX _PAGE_NO_EXEC
+#define __NR _PAGE_NO_READ
+#define ___W _PAGE_WRITE
+#define ___A _PAGE_ACCESSED
+#define ___R (_PAGE_SILENT_READ | _PAGE_ACCESSED)
+#define __PC _page_cachable_default
+
#define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_NO_READ | \
_page_cachable_default)
#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \
@@ -414,8 +422,6 @@ static inline pte_t pte_mkyoung(pte_t pte)
return pte;
}
-#define pte_sw_mkyoung pte_mkyoung
-
#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
static inline int pte_huge(pte_t pte) { return pte_val(pte) & _PAGE_HUGE; }
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index ad6df1c..f814e43 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -158,23 +158,23 @@ void __update_cache(unsigned long address, pte_t pte)
static inline void setup_protection_map(void)
{
if (cpu_has_rixi) {
- protection_map[0] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
- protection_map[1] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
- protection_map[2] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
- protection_map[3] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
- protection_map[4] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
- protection_map[5] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
- protection_map[6] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
- protection_map[7] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
-
- protection_map[8] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_NO_READ);
- protection_map[9] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC);
- protection_map[10] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE | _PAGE_NO_READ);
- protection_map[11] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_NO_EXEC | _PAGE_WRITE);
- protection_map[12] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
- protection_map[13] = __pgprot(_page_cachable_default | _PAGE_PRESENT);
- protection_map[14] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
- protection_map[15] = __pgprot(_page_cachable_default | _PAGE_PRESENT | _PAGE_WRITE);
+ protection_map[0] = __pgprot(__PC | __PP | __NX | __NR);
+ protection_map[1] = __pgprot(__PC | __PP | __NX | ___R);
+ protection_map[2] = __pgprot(__PC | __PP | __NX | __NR);
+ protection_map[3] = __pgprot(__PC | __PP | __NX | ___R);
+ protection_map[4] = __pgprot(__PC | __PP | ___R);
+ protection_map[5] = __pgprot(__PC | __PP | ___R);
+ protection_map[6] = __pgprot(__PC | __PP | ___R);
+ protection_map[7] = __pgprot(__PC | __PP | ___R);
+
+ protection_map[8] = __pgprot(__PC | __PP | __NX | __NR);
+ protection_map[9] = __pgprot(__PC | __PP | __NX | ___R);
+ protection_map[10] = __pgprot(__PC | __PP | __NX | ___W | __NR);
+ protection_map[11] = __pgprot(__PC | __PP | __NX | ___W | ___R);
+ protection_map[12] = __pgprot(__PC | __PP | ___R);
+ protection_map[13] = __pgprot(__PC | __PP | ___R);
+ protection_map[14] = __pgprot(__PC | __PP | ___W | ___R);
+ protection_map[15] = __pgprot(__PC | __PP | ___W | ___R);
} else {
protection_map[0] = PAGE_NONE;
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index b5278ec..fa5c73f 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -244,22 +244,6 @@ static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addres
}
#endif
-/*
- * On some architectures hardware does not set page access bit when accessing
- * memory page, it is responsibilty of software setting this bit. It brings
- * out extra page fault penalty to track page access bit. For optimization page
- * access bit can be set during all page fault flow on these arches.
- * To be differentiate with macro pte_mkyoung, this macro is used on platforms
- * where software maintains page access bit.
- */
-#ifndef pte_sw_mkyoung
-static inline pte_t pte_sw_mkyoung(pte_t pte)
-{
- return pte;
-}
-#define pte_sw_mkyoung pte_sw_mkyoung
-#endif
-
#ifndef pte_savedwrite
#define pte_savedwrite pte_write
#endif
diff --git a/mm/memory.c b/mm/memory.c
index c7c8960..8bb31c4 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2704,7 +2704,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
}
flush_cache_page(vma, vmf->address, pte_pfn(vmf->orig_pte));
entry = mk_pte(new_page, vma->vm_page_prot);
- entry = pte_sw_mkyoung(entry);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
/*
* Clear the pte entry and flush it first, before updating the
@@ -3379,7 +3378,6 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
__SetPageUptodate(page);
entry = mk_pte(page, vma->vm_page_prot);
- entry = pte_sw_mkyoung(entry);
if (vma->vm_flags & VM_WRITE)
entry = pte_mkwrite(pte_mkdirty(entry));
@@ -3662,7 +3660,6 @@ vm_fault_t alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
flush_icache_page(vma, page);
entry = mk_pte(page, vma->vm_page_prot);
- entry = pte_sw_mkyoung(entry);
if (write)
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
/* copy-on-write page */
--
1.8.3.1