[PATCH v4 13/36] loongarch: Implement the new page table range API

From: Matthew Wilcox (Oracle)
Date: Wed Mar 15 2023 - 01:15:46 EST


Add update_mmu_cache_range() and change _PFN_SHIFT to PFN_PTE_SHIFT.
It would probably be more efficient to implement __update_tlb() by
flushing the entire folio instead of calling __update_tlb() N times,
but I'll leave that for someone who understands the architecture better.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: WANG Xuerui <kernel@xxxxxxxxxx>
Cc: loongarch@xxxxxxxxxxxxxxx
---
arch/loongarch/include/asm/cacheflush.h | 2 ++
arch/loongarch/include/asm/pgtable-bits.h | 4 ++--
arch/loongarch/include/asm/pgtable.h | 28 ++++++++++++-----------
arch/loongarch/mm/pgtable.c | 2 +-
arch/loongarch/mm/tlb.c | 2 +-
5 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/arch/loongarch/include/asm/cacheflush.h b/arch/loongarch/include/asm/cacheflush.h
index 0681788eb474..7907eb42bfbd 100644
--- a/arch/loongarch/include/asm/cacheflush.h
+++ b/arch/loongarch/include/asm/cacheflush.h
@@ -47,8 +47,10 @@ void local_flush_icache_range(unsigned long start, unsigned long end);
#define flush_cache_vmap(start, end) do { } while (0)
#define flush_cache_vunmap(start, end) do { } while (0)
#define flush_icache_page(vma, page) do { } while (0)
+#define flush_icache_pages(vma, page) do { } while (0)
#define flush_icache_user_page(vma, page, addr, len) do { } while (0)
#define flush_dcache_page(page) do { } while (0)
+#define flush_dcache_folio(folio) do { } while (0)
#define flush_dcache_mmap_lock(mapping) do { } while (0)
#define flush_dcache_mmap_unlock(mapping) do { } while (0)

diff --git a/arch/loongarch/include/asm/pgtable-bits.h b/arch/loongarch/include/asm/pgtable-bits.h
index 8b98d22a145b..a1eb2e25446b 100644
--- a/arch/loongarch/include/asm/pgtable-bits.h
+++ b/arch/loongarch/include/asm/pgtable-bits.h
@@ -48,12 +48,12 @@
#define _PAGE_NO_EXEC (_ULCAST_(1) << _PAGE_NO_EXEC_SHIFT)
#define _PAGE_RPLV (_ULCAST_(1) << _PAGE_RPLV_SHIFT)
#define _CACHE_MASK (_ULCAST_(3) << _CACHE_SHIFT)
-#define _PFN_SHIFT (PAGE_SHIFT - 12 + _PAGE_PFN_SHIFT)
+#define PFN_PTE_SHIFT (PAGE_SHIFT - 12 + _PAGE_PFN_SHIFT)

#define _PAGE_USER (PLV_USER << _PAGE_PLV_SHIFT)
#define _PAGE_KERN (PLV_KERN << _PAGE_PLV_SHIFT)

-#define _PFN_MASK (~((_ULCAST_(1) << (_PFN_SHIFT)) - 1) & \
+#define _PFN_MASK (~((_ULCAST_(1) << (PFN_PTE_SHIFT)) - 1) & \
((_ULCAST_(1) << (_PAGE_PFN_END_SHIFT)) - 1))

/*
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
index d28fb9dbec59..13aad0003e9a 100644
--- a/arch/loongarch/include/asm/pgtable.h
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -237,9 +237,9 @@ extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd);

#define pte_page(x) pfn_to_page(pte_pfn(x))
-#define pte_pfn(x) ((unsigned long)(((x).pte & _PFN_MASK) >> _PFN_SHIFT))
-#define pfn_pte(pfn, prot) __pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
-#define pfn_pmd(pfn, prot) __pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#define pte_pfn(x) ((unsigned long)(((x).pte & _PFN_MASK) >> PFN_PTE_SHIFT))
+#define pfn_pte(pfn, prot) __pte(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
+#define pfn_pmd(pfn, prot) __pmd(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))

/*
* Initialize a new pgd / pud / pmd table with invalid pointers.
@@ -334,12 +334,6 @@ static inline void set_pte(pte_t *ptep, pte_t pteval)
}
}

-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep, pte_t pteval)
-{
- set_pte(ptep, pteval);
-}
-
static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
/* Preserve global status for the pair */
@@ -445,11 +439,19 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
extern void __update_tlb(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep);

-static inline void update_mmu_cache(struct vm_area_struct *vma,
- unsigned long address, pte_t *ptep)
+static inline void update_mmu_cache_range(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep, unsigned int nr)
{
- __update_tlb(vma, address, ptep);
+ for (;;) {
+ __update_tlb(vma, address, ptep);
+ if (--nr == 0)
+ break;
+ address += PAGE_SIZE;
+ ptep++;
+ }
}
+#define update_mmu_cache(vma, addr, ptep) \
+ update_mmu_cache_range(vma, addr, ptep, 1)

#define __HAVE_ARCH_UPDATE_MMU_TLB
#define update_mmu_tlb update_mmu_cache
@@ -462,7 +464,7 @@ static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,

static inline unsigned long pmd_pfn(pmd_t pmd)
{
- return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT;
+ return (pmd_val(pmd) & _PFN_MASK) >> PFN_PTE_SHIFT;
}

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/arch/loongarch/mm/pgtable.c b/arch/loongarch/mm/pgtable.c
index 36a6dc0148ae..1260cf30e3ee 100644
--- a/arch/loongarch/mm/pgtable.c
+++ b/arch/loongarch/mm/pgtable.c
@@ -107,7 +107,7 @@ pmd_t mk_pmd(struct page *page, pgprot_t prot)
{
pmd_t pmd;

- pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
+ pmd_val(pmd) = (page_to_pfn(page) << PFN_PTE_SHIFT) | pgprot_val(prot);

return pmd;
}
diff --git a/arch/loongarch/mm/tlb.c b/arch/loongarch/mm/tlb.c
index 8bad6b0cff59..73652930b268 100644
--- a/arch/loongarch/mm/tlb.c
+++ b/arch/loongarch/mm/tlb.c
@@ -246,7 +246,7 @@ static void output_pgtable_bits_defines(void)
pr_define("_PAGE_WRITE_SHIFT %d\n", _PAGE_WRITE_SHIFT);
pr_define("_PAGE_NO_READ_SHIFT %d\n", _PAGE_NO_READ_SHIFT);
pr_define("_PAGE_NO_EXEC_SHIFT %d\n", _PAGE_NO_EXEC_SHIFT);
- pr_define("_PFN_SHIFT %d\n", _PFN_SHIFT);
+ pr_define("PFN_PTE_SHIFT %d\n", PFN_PTE_SHIFT);
pr_debug("\n");
}

--
2.39.2