Re: [PATCH v3 00/34] New page table range API

From: Mike Rapoport
Date: Fri Mar 03 2023 - 09:20:03 EST

On Tue, Feb 28, 2023 at 09:37:03PM +0000, Matthew Wilcox (Oracle) wrote:
> This patchset changes the API used by the MM to set up page table entries.
> The four APIs are:
> set_ptes(mm, addr, ptep, pte, nr)
> update_mmu_cache_range(vma, addr, ptep, nr)
> flush_dcache_folio(folio)
> flush_icache_pages(vma, page, nr)
>
> flush_dcache_folio() isn't technically new, but no architecture
> implemented it, so I've done that for you. The old APIs remain around
> but are mostly implemented by calling the new interfaces.
>
> The new APIs are based around setting up N page table entries at once.
> The N entries belong to the same PMD, the same folio and the same VMA,
> so ptep++ is a legitimate operation, and locking is taken care of for
> you. Some architectures can do a better job of it than just a loop,
> but I have hesitated to make too deep a change to architectures I don't
> understand well.

The new set_ptes() looks unnecessarily duplicated all over arch/
What do you say about adding the patch below on top of the series?
Ideally it should be split into per-arch bits, but I can send it separately
as a cleanup on top.

diff --git a/arch/alpha/include/asm/pgtable.h b/arch/alpha/include/asm/pgtable.h
index 1e3354e9731b..65fb9e66675d 100644
--- a/arch/alpha/include/asm/pgtable.h
+++ b/arch/alpha/include/asm/pgtable.h
@@ -37,6 +37,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_val(pte) += 1UL << 32;
}
}
+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

/* PMD_SHIFT determines the size of the area a second-level page table can map */
diff --git a/arch/arc/include/asm/pgtable-bits-arcv2.h b/arch/arc/include/asm/pgtable-bits-arcv2.h
index 4a1b2ce204c6..06d8039180c0 100644
--- a/arch/arc/include/asm/pgtable-bits-arcv2.h
+++ b/arch/arc/include/asm/pgtable-bits-arcv2.h
@@ -100,19 +100,6 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
void update_mmu_cache_range(struct vm_area_struct *vma, unsigned long address,
pte_t *ptep, unsigned int nr);

diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 6525ac82bd50..0d326b201797 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -209,6 +209,7 @@ extern void __sync_icache_dcache(pte_t pteval);

void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pteval, unsigned int nr);
+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 4d1b79dbff16..a8d6460c5c9f 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -369,6 +369,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_val(pte) += PAGE_SIZE;
}
}
+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

/*
diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
index a30ae048233e..e426f1820deb 100644
--- a/arch/csky/include/asm/pgtable.h
+++ b/arch/csky/include/asm/pgtable.h
@@ -91,20 +91,6 @@ static inline void set_pte(pte_t *p, pte_t pte)
smp_mb();
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
static inline pte_t *pmd_page_vaddr(pmd_t pmd)
{
unsigned long ptr;
diff --git a/arch/hexagon/include/asm/pgtable.h b/arch/hexagon/include/asm/pgtable.h
index f58f1d920769..67ab91662e83 100644
--- a/arch/hexagon/include/asm/pgtable.h
+++ b/arch/hexagon/include/asm/pgtable.h
@@ -345,26 +345,6 @@ static inline int pte_exec(pte_t pte)
#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))

-/*
- * set_ptes - update page table and do whatever magic may be
- * necessary to make the underlying hardware/firmware take note.
- *
- * VM may require a virtual instruction to alert the MMU.
- */
-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
static inline unsigned long pmd_page_vaddr(pmd_t pmd)
{
return (unsigned long)__va(pmd_val(pmd) & PAGE_MASK);
diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h
index 0c2be4ea664b..65a6e3b30721 100644
--- a/arch/ia64/include/asm/pgtable.h
+++ b/arch/ia64/include/asm/pgtable.h
@@ -303,19 +303,6 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
*ptep = pteval;
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, add, ptep, pte, 1)
-
/*
* Make page protection values cacheable, uncacheable, or write-
* combining. Note that "protection" is really a misnomer here as the
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index 9154d317ffb4..d4b0ca7b4bf7 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -346,6 +346,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
}
}

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
diff --git a/arch/m68k/include/asm/pgtable_mm.h b/arch/m68k/include/asm/pgtable_mm.h
index 400206c17c97..8c2db20abdb6 100644
--- a/arch/m68k/include/asm/pgtable_mm.h
+++ b/arch/m68k/include/asm/pgtable_mm.h
@@ -32,20 +32,6 @@
*(pteptr) = (pteval); \
} while(0)

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
/* PMD_SHIFT determines the size of the area a second-level page table can map */
#if CONFIG_PGTABLE_LEVELS == 3
#define PMD_SHIFT 18
diff --git a/arch/microblaze/include/asm/pgtable.h b/arch/microblaze/include/asm/pgtable.h
index a01e1369b486..3e7643a986ad 100644
--- a/arch/microblaze/include/asm/pgtable.h
+++ b/arch/microblaze/include/asm/pgtable.h
@@ -335,20 +335,6 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
*ptep = pte;
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += 1 << PFN_SHIFT_OFFSET;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep)
diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 0cf0455e6ae8..18b77567ef72 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -108,6 +108,7 @@ do { \
static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte, unsigned int nr);

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

#if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
diff --git a/arch/nios2/include/asm/pgtable.h b/arch/nios2/include/asm/pgtable.h
index 8a77821a17a5..2a994b225a41 100644
--- a/arch/nios2/include/asm/pgtable.h
+++ b/arch/nios2/include/asm/pgtable.h
@@ -193,6 +193,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
}
}

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

static inline int pmd_none(pmd_t pmd)
diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h
index 1a7077150d7b..8f27730a9ab7 100644
--- a/arch/openrisc/include/asm/pgtable.h
+++ b/arch/openrisc/include/asm/pgtable.h
@@ -47,20 +47,6 @@ extern void paging_init(void);
*/
#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
/*
* (pmds are folded into pgds so this doesn't get actually called,
* but the define is needed for a generic inline function.)
diff --git a/arch/parisc/include/asm/pgtable.h b/arch/parisc/include/asm/pgtable.h
index 78ee9816f423..cd04e85cb012 100644
--- a/arch/parisc/include/asm/pgtable.h
+++ b/arch/parisc/include/asm/pgtable.h
@@ -73,6 +73,7 @@ extern void __update_cache(pte_t pte);
mb(); \
} while(0)

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

#endif /* !__ASSEMBLY__ */
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index bf1263ff7e67..f10b6c2f8ade 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -43,6 +43,7 @@ struct mm_struct;

void set_ptes(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
pte_t pte, unsigned int nr);
+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
#define update_mmu_cache(vma, addr, ptep) \
update_mmu_cache_range(vma, addr, ptep, 1);
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 3a3a776fc047..8bc49496f8a6 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -473,6 +473,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
pte_val(pteval) += 1 << _PAGE_PFN_SHIFT;
}
}
+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

static inline void pte_clear(struct mm_struct *mm,
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 46bf475116f1..2fc20558af6b 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -1346,6 +1346,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
}
}

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

/*
diff --git a/arch/sh/include/asm/pgtable_32.h b/arch/sh/include/asm/pgtable_32.h
index 03ba1834e126..d2f17e944bea 100644
--- a/arch/sh/include/asm/pgtable_32.h
+++ b/arch/sh/include/asm/pgtable_32.h
@@ -319,6 +319,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
}
}

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)

/*
diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h
index 47ae55ea1837..7fbc7772a9b7 100644
--- a/arch/sparc/include/asm/pgtable_32.h
+++ b/arch/sparc/include/asm/pgtable_32.h
@@ -101,20 +101,6 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
srmmu_swap((unsigned long *)ptep, pte_val(pteval));
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
static inline int srmmu_device_memory(unsigned long x)
{
return ((x & 0xF0000000) != 0);
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index d5c0088e0c6a..fddca662ba1b 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -924,6 +924,7 @@ static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
}
}

+#define set_ptes set_ptes
#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1);

#define pte_clear(mm,addr,ptep) \
diff --git a/arch/um/include/asm/pgtable.h b/arch/um/include/asm/pgtable.h
index ca78c90ae74f..60d2b20ff218 100644
--- a/arch/um/include/asm/pgtable.h
+++ b/arch/um/include/asm/pgtable.h
@@ -242,20 +242,6 @@ static inline void set_pte(pte_t *pteptr, pte_t pteval)
if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
#define __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t pte_a, pte_t pte_b)
{
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index f424371ea143..1e5fd352880d 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1019,22 +1019,6 @@ static inline pud_t native_local_pudp_get_and_clear(pud_t *pudp)
return res;
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- page_table_check_ptes_set(mm, addr, ptep, pte, nr);
-
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte = __pte(pte_val(pte) + PAGE_SIZE);
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 293101530541..adeee96518b9 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -306,20 +306,6 @@ static inline void set_pte(pte_t *ptep, pte_t pte)
update_pte(ptep, pte);
}

-static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pte, unsigned int nr)
-{
- for (;;) {
- set_pte(ptep, pte);
- if (--nr == 0)
- break;
- ptep++;
- pte_val(pte) += PAGE_SIZE;
- }
-}
-
-#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
-
static inline void
set_pmd(pmd_t *pmdp, pmd_t pmdval)
{
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index c63cd44777ec..ef204712eda3 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -172,6 +172,24 @@ static inline int pmd_young(pmd_t pmd)
}
#endif

+#ifndef set_ptes
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned int nr)
+{
+ page_table_check_ptes_set(mm, addr, ptep, pte, nr);
+
+ for (;;) {
+ set_pte(ptep, pte);
+ if (--nr == 0)
+ break;
+ ptep++;
+ pte = __pte(pte_val(pte) + PAGE_SIZE);
+ }
+}
+#define set_ptes set_ptes
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
+#endif
+
#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
extern int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,

--
Sincerely yours,
Mike.