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authorAnshuman Khandual <anshuman.khandual@arm.com>2019-07-16 16:27:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-16 19:23:22 -0700
commit0f472d04f59ff89d15b2a1c4eafde7317ddd67a2 (patch)
tree20786684171109ec50859a88c6a354e12e2a8390
parent6b95ab4218bfa59bc315105127ffe03aef3b5742 (diff)
downloadlinux-0f472d04f59ff89d15b2a1c4eafde7317ddd67a2.tar.bz2
mm/ioremap: probe platform for p4d huge map support
Finish up what commit c2febafc6773 ("mm: convert generic code to 5-level paging") started while levelling up P4D huge mapping support at par with PUD and PMD. A new arch call back arch_ioremap_p4d_supported() is added which just maintains status quo (P4D huge map not supported) on x86, arm64 and powerpc. When HAVE_ARCH_HUGE_VMAP is enabled its just a simple check from the arch about the support, hence runtime effects are minimal. Link: http://lkml.kernel.org/r/1561699231-20991-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/arm64/mm/mmu.c5
-rw-r--r--arch/powerpc/mm/book3s64/radix_pgtable.c5
-rw-r--r--arch/x86/mm/ioremap.c5
-rw-r--r--include/linux/io.h1
-rw-r--r--lib/ioremap.c2
5 files changed, 18 insertions, 0 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 1b49c08dfa2b..e661469cabdd 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -942,6 +942,11 @@ void *__init fixmap_remap_fdt(phys_addr_t dt_phys)
return dt_virt;
}
+int __init arch_ioremap_p4d_supported(void)
+{
+ return 0;
+}
+
int __init arch_ioremap_pud_supported(void)
{
/*
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 65c2ba1e1783..b4ca9e95e678 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -1237,3 +1237,8 @@ int radix__ioremap_range(unsigned long ea, phys_addr_t pa, unsigned long size,
return 0;
}
}
+
+int __init arch_ioremap_p4d_supported(void)
+{
+ return 0;
+}
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index e500f1df1140..63e99f15d7cf 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -459,6 +459,11 @@ void iounmap(volatile void __iomem *addr)
}
EXPORT_SYMBOL(iounmap);
+int __init arch_ioremap_p4d_supported(void)
+{
+ return 0;
+}
+
int __init arch_ioremap_pud_supported(void)
{
#ifdef CONFIG_X86_64
diff --git a/include/linux/io.h b/include/linux/io.h
index 9876e5801a9d..accac822336a 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -33,6 +33,7 @@ static inline int ioremap_page_range(unsigned long addr, unsigned long end,
#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
diff --git a/lib/ioremap.c b/lib/ioremap.c
index a95161d9c883..0a2ffadc6d71 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -30,6 +30,8 @@ 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())