[PATCH v13 10/14] mm/vmalloc: provide fallback arch huge vmap support functions

Nicholas Piggin
2021-03-17T06:26:34Z

If an architecture doesn't support a particular page table level as
a huge vmap page size then allow it to skip defining the support
query function.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/arm64/include/asm/vmalloc.h | 7 +++----
arch/powerpc/include/asm/vmalloc.h | 7 +++----
arch/x86/include/asm/vmalloc.h | 13 +++++--------
include/linux/vmalloc.h | 24 ++++++++++++++++++++----
4 files changed, 31 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/include/asm/vmalloc.h b/arch/arm64/include/asm/vmalloc.h
index fc9a12d6cc1a..7a22aeea9bb5 100644
--- a/arch/arm64/include/asm/vmalloc.h
+++ b/arch/arm64/include/asm/vmalloc.h
@@ -4,11 +4,8 @@
#include <asm/page.h>

#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static inline bool arch_vmap_p4d_supported(pgprot_t prot)
-{
- return false;
-}

+#define arch_vmap_pud_supported arch_vmap_pud_supported
static inline bool arch_vmap_pud_supported(pgprot_t prot)
{
/*
@@ -19,11 +16,13 @@ static inline bool arch_vmap_pud_supported(pgprot_t prot)
!IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
}

+#define arch_vmap_pmd_supported arch_vmap_pmd_supported
static inline bool arch_vmap_pmd_supported(pgprot_t prot)
{
/* See arch_vmap_pud_supported() */
return !IS_ENABLED(CONFIG_PTDUMP_DEBUGFS);
}
+
#endif

#endif /* _ASM_ARM64_VMALLOC_H */
diff --git a/arch/powerpc/include/asm/vmalloc.h b/arch/powerpc/include/asm/vmalloc.h
index 3f0c153befb0..4c69ece52a31 100644
--- a/arch/powerpc/include/asm/vmalloc.h
+++ b/arch/powerpc/include/asm/vmalloc.h
@@ -5,21 +5,20 @@
#include <asm/page.h>

#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static inline bool arch_vmap_p4d_supported(pgprot_t prot)
-{
- return false;
-}

+#define arch_vmap_pud_supported arch_vmap_pud_supported
static inline bool arch_vmap_pud_supported(pgprot_t prot)
{
/* HPT does not cope with large pages in the vmalloc area */
return radix_enabled();
}

+#define arch_vmap_pmd_supported arch_vmap_pmd_supported
static inline bool arch_vmap_pmd_supported(pgprot_t prot)
{
return radix_enabled();
}
+
#endif

#endif /* _ASM_POWERPC_VMALLOC_H */
diff --git a/arch/x86/include/asm/vmalloc.h b/arch/x86/include/asm/vmalloc.h
index e714b00fc0ca..49ce331f3ac6 100644
--- a/arch/x86/include/asm/vmalloc.h
+++ b/arch/x86/include/asm/vmalloc.h
@@ -6,24 +6,21 @@
#include <asm/pgtable_areas.h>

#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static inline bool arch_vmap_p4d_supported(pgprot_t prot)
-{
- return false;
-}

+#ifdef CONFIG_X86_64
+#define arch_vmap_pud_supported arch_vmap_pud_supported
static inline bool arch_vmap_pud_supported(pgprot_t prot)
{
-#ifdef CONFIG_X86_64
return boot_cpu_has(X86_FEATURE_GBPAGES);
-#else
- return false;
-#endif
}
+#endif

+#define arch_vmap_pmd_supported arch_vmap_pmd_supported
static inline bool arch_vmap_pmd_supported(pgprot_t prot)
{
return boot_cpu_has(X86_FEATURE_PSE);
}
+
#endif

#endif /* _ASM_X86_VMALLOC_H */
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 4b897a4a408b..82b45e1f28ff 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -78,10 +78,26 @@ 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; }
+/* archs that select HAVE_ARCH_HUGE_VMAP should override one or more of these */
+#ifndef arch_vmap_p4d_supported
+static inline bool arch_vmap_p4d_supported(pgprot_t prot)
+{
+ return false;
+}
+#endif
+
+#ifndef arch_vmap_pud_supported
+static inline bool arch_vmap_pud_supported(pgprot_t prot)
+{
+ return false;
+}
+#endif
+
+#ifndef arch_vmap_pmd_supported
+static inline bool arch_vmap_pmd_supported(pgprot_t prot)
+{
+ return false;
+}
#endif

/*
--
2.23.0