[PATCH v13 06/14] mm: HUGE_VMAP arch support cleanup

[PATCH v13 06/14] mm: HUGE_VMAP arch support cleanup

[Nicholas Piggin]

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@lists.ozlabs.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 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/debug_vm_pgtable.c                    |  4 +-
 mm/ioremap.c                             | 94 ++++++++++--------------
 11 files changed, 87 insertions(+), 80 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 7484ea4f6ba0..639b9de61b1d 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1316,12 +1316,12 @@ 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.
@@ -1331,9 +1331,9 @@ 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 df92211cf771..4b897a4a408b 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -78,6 +78,12 @@ 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 53b278845b88..7382b80897f2 100644
--- a/init/main.c
+++ b/init/main.c
@@ -837,7 +837,6 @@ 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/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index a9bd6ce1ba02..05efe98a9ac2 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -247,7 +247,7 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot)
 {
 	pmd_t pmd;
 
-	if (!arch_ioremap_pmd_supported())
+	if (!arch_vmap_pmd_supported(prot))
 		return;
 
 	pr_debug("Validating PMD huge\n");
@@ -385,7 +385,7 @@ static void __init pud_huge_tests(pud_t *pudp, unsigned long pfn, pgprot_t prot)
 {
 	pud_t pud;
 
-	if (!arch_ioremap_pud_supported())
+	if (!arch_vmap_pud_supported(prot))
 		return;
 
 	pr_debug("Validating PUD huge\n");
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
-- 
2.23.0

Re: [PATCH v13 06/14] mm: HUGE_VMAP arch support cleanup

[Christophe Leroy]

Le 17/03/2021 à 07:23, Nicholas Piggin a écrit :
> 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@lists.ozlabs.org
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: x86@kernel.org
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>   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/debug_vm_pgtable.c                    |  4 +-
>   mm/ioremap.c                             | 94 ++++++++++--------------
>   11 files changed, 87 insertions(+), 80 deletions(-)
> 

> 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;

Must be an int, not a bool.

>   
>   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,

Christophe

Re: [PATCH v13 06/14] mm: HUGE_VMAP arch support cleanup

[Christophe Leroy]

Le 28/04/2021 à 10:32, Christophe Leroy a écrit :
> 
> 
> Le 17/03/2021 à 07:23, Nicholas Piggin a écrit :
>> 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@lists.ozlabs.org
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will@kernel.org>
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Borislav Petkov <bp@alien8.de>
>> Cc: x86@kernel.org
>> Cc: "H. Peter Anvin" <hpa@zytor.com>
>> Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
>> Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arm64]
>> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
>> ---
>>   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/debug_vm_pgtable.c                    |  4 +-
>>   mm/ioremap.c                             | 94 ++++++++++--------------
>>   11 files changed, 87 insertions(+), 80 deletions(-)
>>
> 
>> 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;
> 
> Must be an int, not a bool.

And the initial value seems wrong. Should be P4D_SHIFT ?

> 
>>   static int __init set_nohugeiomap(char *str)
>>   {
>> -    ioremap_huge_disabled = 1;
>> +    iomap_max_page_shift = P4D_SHIFT;

And PAGE_SHIFT here when NO hugeiomap ?

>>       return 0;
>>   }
>>   early_param("nohugeiomap", set_nohugeiomap);

Christophe

[PATCH v13 07/14] powerpc: inline huge vmap supported functions

[Nicholas Piggin]

This allows unsupported levels to be constant folded away, and so
p4d_free_pud_page can be removed because it's no longer linked to.

Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/include/asm/vmalloc.h       | 19 ++++++++++++++++---
 arch/powerpc/mm/book3s64/radix_pgtable.c | 21 ---------------------
 2 files changed, 16 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/include/asm/vmalloc.h b/arch/powerpc/include/asm/vmalloc.h
index 105abb73f075..3f0c153befb0 100644
--- a/arch/powerpc/include/asm/vmalloc.h
+++ b/arch/powerpc/include/asm/vmalloc.h
@@ -1,12 +1,25 @@
 #ifndef _ASM_POWERPC_VMALLOC_H
 #define _ASM_POWERPC_VMALLOC_H
 
+#include <asm/mmu.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);
+static inline bool arch_vmap_p4d_supported(pgprot_t prot)
+{
+	return false;
+}
+
+static inline bool arch_vmap_pud_supported(pgprot_t prot)
+{
+	/* HPT does not cope with large pages in the vmalloc area */
+	return radix_enabled();
+}
+
+static inline bool arch_vmap_pmd_supported(pgprot_t prot)
+{
+	return radix_enabled();
+}
 #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 743807fc210f..8da62afccee5 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -1082,22 +1082,6 @@ void radix__ptep_modify_prot_commit(struct vm_area_struct *vma,
 	set_pte_at(mm, addr, ptep, pte);
 }
 
-bool arch_vmap_pud_supported(pgprot_t prot)
-{
-	/* HPT does not cope with large pages in the vmalloc area */
-	return radix_enabled();
-}
-
-bool arch_vmap_pmd_supported(pgprot_t prot)
-{
-	return radix_enabled();
-}
-
-int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
-{
-	return 0;
-}
-
 int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
 {
 	pte_t *ptep = (pte_t *)pud;
@@ -1181,8 +1165,3 @@ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
 
 	return 1;
 }
-
-bool arch_vmap_p4d_supported(pgprot_t prot)
-{
-	return false;
-}
-- 
2.23.0

[PATCH v13 14/14] powerpc/64s/radix: Enable huge vmalloc mappings

[Nicholas Piggin]

This reduces TLB misses by nearly 30x on a `git diff` workload on a
2-node POWER9 (59,800 -> 2,100) and reduces CPU cycles by 0.54%, due
to vfs hashes being allocated with 2MB pages.

Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 .../admin-guide/kernel-parameters.txt         |  2 ++
 arch/powerpc/Kconfig                          |  1 +
 arch/powerpc/kernel/module.c                  | 22 +++++++++++++++----
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 04545725f187..1f481f904895 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3243,6 +3243,8 @@
 
 	nohugeiomap	[KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
 
+	nohugevmalloc	[PPC] Disable kernel huge vmalloc mappings.
+
 	nosmt		[KNL,S390] Disable symmetric multithreading (SMT).
 			Equivalent to smt=1.
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 386ae12d8523..b7cade9566da 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -181,6 +181,7 @@ config PPC
 	select GENERIC_GETTIMEOFDAY
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_ARCH_HUGE_VMAP		if PPC_BOOK3S_64 && PPC_RADIX_MMU
+	select HAVE_ARCH_HUGE_VMALLOC		if HAVE_ARCH_HUGE_VMAP
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_KASAN			if PPC32 && PPC_PAGE_SHIFT <= 14
 	select HAVE_ARCH_KASAN_VMALLOC		if PPC32 && PPC_PAGE_SHIFT <= 14
diff --git a/arch/powerpc/kernel/module.c b/arch/powerpc/kernel/module.c
index a211b0253cdb..cdb2d88c54e7 100644
--- a/arch/powerpc/kernel/module.c
+++ b/arch/powerpc/kernel/module.c
@@ -8,6 +8,7 @@
 #include <linux/moduleloader.h>
 #include <linux/err.h>
 #include <linux/vmalloc.h>
+#include <linux/mm.h>
 #include <linux/bug.h>
 #include <asm/module.h>
 #include <linux/uaccess.h>
@@ -87,13 +88,26 @@ int module_finalize(const Elf_Ehdr *hdr,
 	return 0;
 }
 
-#ifdef MODULES_VADDR
 void *module_alloc(unsigned long size)
 {
+	unsigned long start = VMALLOC_START;
+	unsigned long end = VMALLOC_END;
+
+#ifdef MODULES_VADDR
 	BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
+	start = MODULES_VADDR;
+	end = MODULES_END;
+#endif
+
+	/*
+	 * Don't do huge page allocations for modules yet until more testing
+	 * is done. STRICT_MODULE_RWX may require extra work to support this
+	 * too.
+	 */
 
-	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
-				    PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
+	return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL,
+				    PAGE_KERNEL_EXEC,
+				    VM_NO_HUGE_VMAP | VM_FLUSH_RESET_PERMS,
+				    NUMA_NO_NODE,
 				    __builtin_return_address(0));
 }
-#endif
-- 
2.23.0

Re: [PATCH v13 14/14] powerpc/64s/radix: Enable huge vmalloc mappings

[Christophe Leroy]

Hi Nick,

Le 17/03/2021 à 07:24, Nicholas Piggin a écrit :
> This reduces TLB misses by nearly 30x on a `git diff` workload on a
> 2-node POWER9 (59,800 -> 2,100) and reduces CPU cycles by 0.54%, due
> to vfs hashes being allocated with 2MB pages.
> 
> Cc: linuxppc-dev@lists.ozlabs.org
> Acked-by: Michael Ellerman <mpe@ellerman.id.au>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
>   .../admin-guide/kernel-parameters.txt         |  2 ++
>   arch/powerpc/Kconfig                          |  1 +
>   arch/powerpc/kernel/module.c                  | 22 +++++++++++++++----
>   3 files changed, 21 insertions(+), 4 deletions(-)
> 
> --- a/arch/powerpc/kernel/module.c
> +++ b/arch/powerpc/kernel/module.c
> @@ -8,6 +8,7 @@
>   #include <linux/moduleloader.h>
>   #include <linux/err.h>
>   #include <linux/vmalloc.h>
> +#include <linux/mm.h>
>   #include <linux/bug.h>
>   #include <asm/module.h>
>   #include <linux/uaccess.h>
> @@ -87,13 +88,26 @@ int module_finalize(const Elf_Ehdr *hdr,
>   	return 0;
>   }
>   
> -#ifdef MODULES_VADDR
>   void *module_alloc(unsigned long size)
>   {
> +	unsigned long start = VMALLOC_START;
> +	unsigned long end = VMALLOC_END;
> +
> +#ifdef MODULES_VADDR
>   	BUILD_BUG_ON(TASK_SIZE > MODULES_VADDR);
> +	start = MODULES_VADDR;
> +	end = MODULES_END;
> +#endif
> +
> +	/*
> +	 * Don't do huge page allocations for modules yet until more testing
> +	 * is done. STRICT_MODULE_RWX may require extra work to support this
> +	 * too.
> +	 */
>   
> -	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
> -				    PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,


I think you should add the following in <asm/pgtable.h>

#ifndef MODULES_VADDR
#define MODULES_VADDR VMALLOC_START
#define MODULES_END VMALLOC_END
#endif

And leave module_alloc() as is (just removing the enclosing #ifdef MODULES_VADDR and adding the 
VM_NO_HUGE_VMAP  flag)

This would minimise the conflits with the changes I did in powerpc/next reported by Stephen R.

> +	return __vmalloc_node_range(size, 1, start, end, GFP_KERNEL,
> +				    PAGE_KERNEL_EXEC,
> +				    VM_NO_HUGE_VMAP | VM_FLUSH_RESET_PERMS,
> +				    NUMA_NO_NODE,
>   				    __builtin_return_address(0));
>   }
> -#endif
> 

Re: [PATCH v13 14/14] powerpc/64s/radix: Enable huge vmalloc mappings

[Andrew Morton]

On Thu, 15 Apr 2021 12:23:55 +0200 Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
> > +	 * is done. STRICT_MODULE_RWX may require extra work to support this
> > +	 * too.
> > +	 */
> >   
> > -	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
> > -				    PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
> 
> 
> I think you should add the following in <asm/pgtable.h>
> 
> #ifndef MODULES_VADDR
> #define MODULES_VADDR VMALLOC_START
> #define MODULES_END VMALLOC_END
> #endif
> 
> And leave module_alloc() as is (just removing the enclosing #ifdef MODULES_VADDR and adding the 
> VM_NO_HUGE_VMAP  flag)
> 
> This would minimise the conflits with the changes I did in powerpc/next reported by Stephen R.
> 

I'll drop powerpc-64s-radix-enable-huge-vmalloc-mappings.patch for now,
make life simpler.

Nick, a redo on top of Christophe's changes in linux-next would be best
please.

Re: [PATCH v13 14/14] powerpc/64s/radix: Enable huge vmalloc mappings

[Stephen Rothwell]

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Hi all,

On Thu, 15 Apr 2021 11:55:29 -0700 Andrew Morton <akpm@linux-foundation.org> wrote:
>
> On Thu, 15 Apr 2021 12:23:55 +0200 Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
> > > +	 * is done. STRICT_MODULE_RWX may require extra work to support this
> > > +	 * too.
> > > +	 */
> > >   
> > > -	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
> > > -				    PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,  
> > 
> > 
> > I think you should add the following in <asm/pgtable.h>
> > 
> > #ifndef MODULES_VADDR
> > #define MODULES_VADDR VMALLOC_START
> > #define MODULES_END VMALLOC_END
> > #endif
> > 
> > And leave module_alloc() as is (just removing the enclosing #ifdef MODULES_VADDR and adding the 
> > VM_NO_HUGE_VMAP  flag)
> > 
> > This would minimise the conflits with the changes I did in powerpc/next reported by Stephen R.
> >   
> 
> I'll drop powerpc-64s-radix-enable-huge-vmalloc-mappings.patch for now,
> make life simpler.

I have dropped that patch from linux-next.
-- 
Cheers,
Stephen Rothwell

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Re: [PATCH v13 14/14] powerpc/64s/radix: Enable huge vmalloc mappings

[Nicholas Piggin]

Excerpts from Andrew Morton's message of April 16, 2021 4:55 am:
> On Thu, 15 Apr 2021 12:23:55 +0200 Christophe Leroy <christophe.leroy@csgroup.eu> wrote:
>> > +	 * is done. STRICT_MODULE_RWX may require extra work to support this
>> > +	 * too.
>> > +	 */
>> >   
>> > -	return __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END, GFP_KERNEL,
>> > -				    PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, NUMA_NO_NODE,
>> 
>> 
>> I think you should add the following in <asm/pgtable.h>
>> 
>> #ifndef MODULES_VADDR
>> #define MODULES_VADDR VMALLOC_START
>> #define MODULES_END VMALLOC_END
>> #endif
>> 
>> And leave module_alloc() as is (just removing the enclosing #ifdef MODULES_VADDR and adding the 
>> VM_NO_HUGE_VMAP  flag)
>> 
>> This would minimise the conflits with the changes I did in powerpc/next reported by Stephen R.
>> 
> 
> I'll drop powerpc-64s-radix-enable-huge-vmalloc-mappings.patch for now,
> make life simpler.

Yeah that's fine.

> Nick, a redo on top of Christophe's changes in linux-next would be best
> please.

Will do.

Thanks,
Nick