From e47168f3d1b14af5281cf50c59561d59d28201f9 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 31 Aug 2020 08:30:44 +0000 Subject: [PATCH] powerpc/8xx: Support 16k hugepages with 4k pages The 8xx has 4 page sizes: 4k, 16k, 512k and 8M 4k and 16k can be selected at build time as standard page sizes, and 512k and 8M are hugepages. When 4k standard pages are selected, 16k pages are not available. Allow 16k pages as hugepages when 4k pages are used. To allow that, implement arch_make_huge_pte() which receives the necessary arguments to allow setting the PTE in accordance with the page size: - 512 k pages must have _PAGE_HUGE and _PAGE_SPS. They are set by pte_mkhuge(). arch_make_huge_pte() does nothing. - 16 k pages must have only _PAGE_SPS. arch_make_huge_pte() clears _PAGE_HUGE. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/a518abc29266a708dfbccc8fce9ae6694fe4c2c6.1598862623.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h | 14 ++++++++++++++ arch/powerpc/include/asm/nohash/32/pgtable.h | 2 ++ arch/powerpc/mm/hugetlbpage.c | 2 +- arch/powerpc/mm/nohash/tlb.c | 4 ---- arch/powerpc/mm/ptdump/8xx.c | 5 +++++ include/uapi/asm-generic/hugetlb_encode.h | 1 + include/uapi/linux/mman.h | 1 + 7 files changed, 24 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h index e752a5807a596..39be9aea86db6 100644 --- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h @@ -65,4 +65,18 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm, pte_update(mm, addr, ptep, clr, set, 1); } +#ifdef CONFIG_PPC_4K_PAGES +static inline pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma, + struct page *page, int writable) +{ + size_t size = huge_page_size(hstate_vma(vma)); + + if (size == SZ_16K) + return __pte(pte_val(entry) & ~_PAGE_HUGE); + else + return entry; +} +#define arch_make_huge_pte arch_make_huge_pte +#endif + #endif /* _ASM_POWERPC_NOHASH_32_HUGETLB_8XX_H */ diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h index 80bbc21b87f09..ee2243ba96cfa 100644 --- a/arch/powerpc/include/asm/nohash/32/pgtable.h +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h @@ -235,6 +235,8 @@ static int number_of_cells_per_pte(pmd_t *pmd, pte_basic_t val, int huge) return PAGE_SIZE / SZ_4K; else if (hugepd_ok(*((hugepd_t *)pmd))) return 1; + else if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && !(val & _PAGE_HUGE)) + return SZ_16K / SZ_4K; else return SZ_512K / SZ_4K; } diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c index e7ae2a2c45450..36c3800769fbf 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c @@ -180,7 +180,7 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz if (!hpdp) return NULL; - if (IS_ENABLED(CONFIG_PPC_8xx) && sz == SZ_512K) + if (IS_ENABLED(CONFIG_PPC_8xx) && pshift < PMD_SHIFT) return pte_alloc_map(mm, (pmd_t *)hpdp, addr); BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp)); diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c index 14514585db980..5872f69141d54 100644 --- a/arch/powerpc/mm/nohash/tlb.c +++ b/arch/powerpc/mm/nohash/tlb.c @@ -83,16 +83,12 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { }; #elif defined(CONFIG_PPC_8xx) struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = { - /* we only manage 4k and 16k pages as normal pages */ -#ifdef CONFIG_PPC_4K_PAGES [MMU_PAGE_4K] = { .shift = 12, }, -#else [MMU_PAGE_16K] = { .shift = 14, }, -#endif [MMU_PAGE_512K] = { .shift = 19, }, diff --git a/arch/powerpc/mm/ptdump/8xx.c b/arch/powerpc/mm/ptdump/8xx.c index 8a797dcbf4753..86da2a669680f 100644 --- a/arch/powerpc/mm/ptdump/8xx.c +++ b/arch/powerpc/mm/ptdump/8xx.c @@ -11,8 +11,13 @@ static const struct flag_info flag_array[] = { { +#ifdef CONFIG_PPC_16K_PAGES .mask = _PAGE_HUGE, .val = _PAGE_HUGE, +#else + .mask = _PAGE_SPS, + .val = _PAGE_SPS, +#endif .set = "huge", .clear = " ", }, { diff --git a/include/uapi/asm-generic/hugetlb_encode.h b/include/uapi/asm-generic/hugetlb_encode.h index b0f8e87235bdf..4f3d5aaa11f53 100644 --- a/include/uapi/asm-generic/hugetlb_encode.h +++ b/include/uapi/asm-generic/hugetlb_encode.h @@ -20,6 +20,7 @@ #define HUGETLB_FLAG_ENCODE_SHIFT 26 #define HUGETLB_FLAG_ENCODE_MASK 0x3f +#define HUGETLB_FLAG_ENCODE_16KB (14 << HUGETLB_FLAG_ENCODE_SHIFT) #define HUGETLB_FLAG_ENCODE_64KB (16 << HUGETLB_FLAG_ENCODE_SHIFT) #define HUGETLB_FLAG_ENCODE_512KB (19 << HUGETLB_FLAG_ENCODE_SHIFT) #define HUGETLB_FLAG_ENCODE_1MB (20 << HUGETLB_FLAG_ENCODE_SHIFT) diff --git a/include/uapi/linux/mman.h b/include/uapi/linux/mman.h index 923cc162609c0..f55bc680b5b0a 100644 --- a/include/uapi/linux/mman.h +++ b/include/uapi/linux/mman.h @@ -27,6 +27,7 @@ #define MAP_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT #define MAP_HUGE_MASK HUGETLB_FLAG_ENCODE_MASK +#define MAP_HUGE_16KB HUGETLB_FLAG_ENCODE_16KB #define MAP_HUGE_64KB HUGETLB_FLAG_ENCODE_64KB #define MAP_HUGE_512KB HUGETLB_FLAG_ENCODE_512KB #define MAP_HUGE_1MB HUGETLB_FLAG_ENCODE_1MB