Reviewed-by: Ding Tianhong <dingtianhong@xxxxxxxxxx>
On 2021/1/26 12:45, Nicholas Piggin wrote:
> This changes the awkward approach where architectures provide init
> functions to determine which levels they can provide large mappings for,
> to one where the arch is queried for each call.
>
> This removes code and indirection, and allows constant-folding of dead
> code for unsupported levels.
>
> This also adds a prot argument to the arch query. This is unused
> currently but could help with some architectures (e.g., some powerpc
> processors can't map uncacheable memory with large pages).
>
> Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx> [arm64]
> Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> ---
> arch/arm64/include/asm/vmalloc.h | 8 ++
> arch/arm64/mm/mmu.c | 10 +--
> arch/powerpc/include/asm/vmalloc.h | 8 ++
> arch/powerpc/mm/book3s64/radix_pgtable.c | 8 +-
> arch/x86/include/asm/vmalloc.h | 7 ++
> arch/x86/mm/ioremap.c | 12 +--
> include/linux/io.h | 9 ---
> include/linux/vmalloc.h | 6 ++
> init/main.c | 1 -
> mm/ioremap.c | 94 ++++++++++--------------
> 10 files changed, 85 insertions(+), 78 deletions(-)
>
> diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
> index 2ca708ab9b20..597b40405319 100644
> --- a/arch/arm64/include/asm/vmalloc.h
> +++ b/arch/arm64/include/asm/vmalloc.h
> @@ -1,4 +1,12 @@
> #ifndef _ASM_ARM64_VMALLOC_H
> #define _ASM_ARM64_VMALLOC_H
>
> +#include <asm/page.h>
> +
> +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
> +bool arch_vmap_p4d_supported(pgprot_t prot);
> +bool arch_vmap_pud_supported(pgprot_t prot);
> +bool arch_vmap_pmd_supported(pgprot_t prot);
> +#endif
> +
> #endif /* _ASM_ARM64_VMALLOC_H */
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index ae0c3d023824..1613d290cbd1 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1313,12 +1313,12 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
> return dt_virt;
> }
>
> -int __init arch_ioremap_p4d_supported(void)
> +bool arch_vmap_p4d_supported(pgprot_t prot)
> {
> - return 0;
> + return false;
> }
>
> -int __init arch_ioremap_pud_supported(void)
> +bool arch_vmap_pud_supported(pgprot_t prot)
> {
> /*
> * Only 4k granule supports level 1 block mappings.
> @@ -1328,9 +1328,9 @@ int __init arch_ioremap_pud_supported(void)
> !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
> }
>
> -int __init arch_ioremap_pmd_supported(void)
> +bool arch_vmap_pmd_supported(pgprot_t prot)
> {
> - /* See arch_ioremap_pud_supported() */
> + /* See arch_vmap_pud_supported() */
> return !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
> }
>
> diff --git a/arch/powerpc/include/asm/vmalloc.h b/arch/powerpc/include/asm/vmalloc.h
> index b992dfaaa161..105abb73f075 100644
> --- a/arch/powerpc/include/asm/vmalloc.h
> +++ b/arch/powerpc/include/asm/vmalloc.h
> @@ -1,4 +1,12 @@
> #ifndef _ASM_POWERPC_VMALLOC_H
> #define _ASM_POWERPC_VMALLOC_H
>
> +#include <asm/page.h>
> +
> +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
> +bool arch_vmap_p4d_supported(pgprot_t prot);
> +bool arch_vmap_pud_supported(pgprot_t prot);
> +bool arch_vmap_pmd_supported(pgprot_t prot);
> +#endif
> +
> #endif /* _ASM_POWERPC_VMALLOC_H */
> diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
> index 98f0b243c1ab..743807fc210f 100644
> --- a/arch/powerpc/mm/book3s64/radix_pgtable.c
> +++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
> @@ -1082,13 +1082,13 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
> set_pte_at(mm, addr, ptep, pte);
> }
>
> -int __init arch_ioremap_pud_supported(void)
> +bool arch_vmap_pud_supported(pgprot_t prot)
> {
> /* HPT does not cope with large pages in the vmalloc area */
> return radix_enabled();
> }
>
> -int __init arch_ioremap_pmd_supported(void)
> +bool arch_vmap_pmd_supported(pgprot_t prot)
> {
> return radix_enabled();
> }
> @@ -1182,7 +1182,7 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
> return 1;
> }
>
> -int __init arch_ioremap_p4d_supported(void)
> +bool arch_vmap_p4d_supported(pgprot_t prot)
> {
> - return 0;
> + return false;
> }
> diff --git a/arch/x86/include/asm/vmalloc.h b/arch/x86/include/asm/vmalloc.h
> index 29837740b520..094ea2b565f3 100644
> --- a/arch/x86/include/asm/vmalloc.h
> +++ b/arch/x86/include/asm/vmalloc.h
> @@ -1,6 +1,13 @@
> #ifndef _ASM_X86_VMALLOC_H
> #define _ASM_X86_VMALLOC_H
>
> +#include <asm/page.h>
> #include <asm/pgtable_areas.h>
>
> +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
> +bool arch_vmap_p4d_supported(pgprot_t prot);
> +bool arch_vmap_pud_supported(pgprot_t prot);
> +bool arch_vmap_pmd_supported(pgprot_t prot);
> +#endif
> +
> #endif /* _ASM_X86_VMALLOC_H */
> diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
> index 9e5ccc56f8e0..fbaf0c447986 100644
> --- a/arch/x86/mm/ioremap.c
> +++ b/arch/x86/mm/ioremap.c
> @@ -481,24 +481,26 @@ void iounmap(volatile void __iomem *addr)
> }
> EXPORT_SYMBOL(iounmap);
>
> -int __init arch_ioremap_p4d_supported(void)
> +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
> +bool arch_vmap_p4d_supported(pgprot_t prot)
> {
> - return 0;
> + return false;
> }
>
> -int __init arch_ioremap_pud_supported(void)
> +bool arch_vmap_pud_supported(pgprot_t prot)
> {
> #ifdef CONFIG_X86_64
> return boot_cpu_has(X86_FEATURE_GBPAGES);
> #else
> - return 0;
> + return false;
> #endif
> }
>
> -int __init arch_ioremap_pmd_supported(void)
> +bool arch_vmap_pmd_supported(pgprot_t prot)
> {
> return boot_cpu_has(X86_FEATURE_PSE);
> }
> +#endif
>
> /*
> * Convert a physical pointer to a virtual kernel pointer for /dev/mem
> diff --git a/include/linux/io.h b/include/linux/io.h
> index 8394c56babc2..f1effd4d7a3c 100644
> --- a/include/linux/io.h
> +++ b/include/linux/io.h
> @@ -31,15 +31,6 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end,
> }
> #endif
>
> -#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
> -void __init ioremap_huge_init(void);
> -int arch_ioremap_p4d_supported(void);
> -int arch_ioremap_pud_supported(void);
> -int arch_ioremap_pmd_supported(void);
> -#else
> -static inline void ioremap_huge_init(void) { }
> -#endif
> -
> /*
> * Managed iomap interface
> */
> diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
> index 80c0181c411d..00bd62bd701e 100644
> --- a/include/linux/vmalloc.h
> +++ b/include/linux/vmalloc.h
> @@ -83,6 +83,12 @@ struct vmap_area {
> };
> };
>
> +#ifndef CONFIG_HAVE_ARCH_HUGE_VMAP
> +static inline bool arch_vmap_p4d_supported(pgprot_t prot) { return false; }
> +static inline bool arch_vmap_pud_supported(pgprot_t prot) { return false; }
> +static inline bool arch_vmap_pmd_supported(pgprot_t prot) { return false; }
> +#endif
> +
> /*
> * Highlevel APIs for driver use
> */
> diff --git a/init/main.c b/init/main.c
> index c68d784376ca..bf9389e5b2e4 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -834,7 +834,6 @@ static void __init mm_init(void)
> pgtable_init();
> debug_objects_mem_init();
> vmalloc_init();
> - ioremap_huge_init();
> /* Should be run before the first non-init thread is created */
> init_espfix_bsp();
> /* Should be run after espfix64 is set up. */
> diff --git a/mm/ioremap.c b/mm/ioremap.c
> index 3f4d36f9745a..3264d0203785 100644
> --- a/mm/ioremap.c
> +++ b/mm/ioremap.c
> @@ -16,49 +16,16 @@
> #include "pgalloc-track.h"
>
> #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
> -static int __read_mostly ioremap_p4d_capable;
> -static int __read_mostly ioremap_pud_capable;
> -static int __read_mostly ioremap_pmd_capable;
> -static int __read_mostly ioremap_huge_disabled;
> +static bool __ro_after_init iomap_max_page_shift = PAGE_SHIFT;
>
> static int __init set_nohugeiomap(char *str)
> {
> - ioremap_huge_disabled = 1;
> + iomap_max_page_shift = P4D_SHIFT;
> return 0;
> }
> early_param("nohugeiomap", set_nohugeiomap);
> -
> -void __init ioremap_huge_init(void)
> -{
> - if (!ioremap_huge_disabled) {
> - if (arch_ioremap_p4d_supported())
> - ioremap_p4d_capable = 1;
> - if (arch_ioremap_pud_supported())
> - ioremap_pud_capable = 1;
> - if (arch_ioremap_pmd_supported())
> - ioremap_pmd_capable = 1;
> - }
> -}
> -
> -static inline int ioremap_p4d_enabled(void)
> -{
> - return ioremap_p4d_capable;
> -}
> -
> -static inline int ioremap_pud_enabled(void)
> -{
> - return ioremap_pud_capable;
> -}
> -
> -static inline int ioremap_pmd_enabled(void)
> -{
> - return ioremap_pmd_capable;
> -}
> -
> -#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
> -static inline int ioremap_p4d_enabled(void) { return 0; }
> -static inline int ioremap_pud_enabled(void) { return 0; }
> -static inline int ioremap_pmd_enabled(void) { return 0; }
> +#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
> +static const bool iomap_max_page_shift = PAGE_SHIFT;
> #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
>
> static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
> @@ -82,9 +49,13 @@ static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
> }
>
> static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
> - phys_addr_t phys_addr, pgprot_t prot)
> + phys_addr_t phys_addr, pgprot_t prot,
> + unsigned int max_page_shift)
> {
> - if (!ioremap_pmd_enabled())
> + if (max_page_shift < PMD_SHIFT)
> + return 0;
> +
> + if (!arch_vmap_pmd_supported(prot))
> return 0;
>
> if ((end - addr) != PMD_SIZE)
> @@ -104,7 +75,7 @@ static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
>
> static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
> phys_addr_t phys_addr, pgprot_t prot,
> - pgtbl_mod_mask *mask)
> + unsigned int max_page_shift, pgtbl_mod_mask *mask)
> {
> pmd_t *pmd;
> unsigned long next;
> @@ -115,7 +86,8 @@ static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
> do {
> next = pmd_addr_end(addr, end);
>
> - if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) {
> + if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
> + max_page_shift)) {
> *mask |= PGTBL_PMD_MODIFIED;
> continue;
> }
> @@ -127,9 +99,13 @@ static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
> }
>
> static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
> - phys_addr_t phys_addr, pgprot_t prot)
> + phys_addr_t phys_addr, pgprot_t prot,
> + unsigned int max_page_shift)
> {
> - if (!ioremap_pud_enabled())
> + if (max_page_shift < PUD_SHIFT)
> + return 0;
> +
> + if (!arch_vmap_pud_supported(prot))
> return 0;
>
> if ((end - addr) != PUD_SIZE)
> @@ -149,7 +125,7 @@ static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
>
> static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
> phys_addr_t phys_addr, pgprot_t prot,
> - pgtbl_mod_mask *mask)
> + unsigned int max_page_shift, pgtbl_mod_mask *mask)
> {
> pud_t *pud;
> unsigned long next;
> @@ -160,21 +136,27 @@ static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
> do {
> next = pud_addr_end(addr, end);
>
> - if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot)) {
> + if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
> + max_page_shift)) {
> *mask |= PGTBL_PUD_MODIFIED;
> continue;
> }
>
> - if (vmap_pmd_range(pud, addr, next, phys_addr, prot, mask))
> + if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
> + max_page_shift, mask))
> return -ENOMEM;
> } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
> return 0;
> }
>
> static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
> - phys_addr_t phys_addr, pgprot_t prot)
> + phys_addr_t phys_addr, pgprot_t prot,
> + unsigned int max_page_shift)
> {
> - if (!ioremap_p4d_enabled())
> + if (max_page_shift < P4D_SHIFT)
> + return 0;
> +
> + if (!arch_vmap_p4d_supported(prot))
> return 0;
>
> if ((end - addr) != P4D_SIZE)
> @@ -194,7 +176,7 @@ static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
>
> static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
> phys_addr_t phys_addr, pgprot_t prot,
> - pgtbl_mod_mask *mask)
> + unsigned int max_page_shift, pgtbl_mod_mask *mask)
> {
> p4d_t *p4d;
> unsigned long next;
> @@ -205,19 +187,22 @@ static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
> do {
> next = p4d_addr_end(addr, end);
>
> - if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) {
> + if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
> + max_page_shift)) {
> *mask |= PGTBL_P4D_MODIFIED;
> continue;
> }
>
> - if (vmap_pud_range(p4d, addr, next, phys_addr, prot, mask))
> + if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
> + max_page_shift, mask))
> return -ENOMEM;
> } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
> return 0;
> }
>
> static int vmap_range(unsigned long addr, unsigned long end,
> - phys_addr_t phys_addr, pgprot_t prot)
> + phys_addr_t phys_addr, pgprot_t prot,
> + unsigned int max_page_shift)
> {
> pgd_t *pgd;
> unsigned long start;
> @@ -232,7 +217,8 @@ static int vmap_range(unsigned long addr, unsigned long end,
> pgd = pgd_offset_k(addr);
> do {
> next = pgd_addr_end(addr, end);
> - err = vmap_p4d_range(pgd, addr, next, phys_addr, prot, &mask);
> + err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
> + max_page_shift, &mask);
> if (err)
> break;
> } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
> @@ -248,7 +234,7 @@ static int vmap_range(unsigned long addr, unsigned long end,
> int ioremap_page_range(unsigned long addr,
> unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
> {
> - return vmap_range(addr, end, phys_addr, prot);
> + return vmap_range(addr, end, phys_addr, prot, iomap_max_page_shift);
> }
>
> #ifdef CONFIG_GENERIC_IOREMAP
>
