path: root/arch
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authorWill Deacon <will.deacon@arm.com>2018-12-28 00:37:53 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:50 -0800
commit8e2d43405b22e98cf5f3730c1829ec1fdbe17ae7 (patch)
treec30cf15a54d92a9e56c9c2c1e5fd9455e816b432 /arch
parent36ddc5a78c878e9b10c323d2fe88b0dae2f487eb (diff)
lib/ioremap: ensure break-before-make is used for huge p4d mappings
Whilst no architectures actually enable support for huge p4d mappings in the vmap area, the code that is implemented should be using break-before-make, as we do for pud and pmd huge entries. Link: http://lkml.kernel.org/r/1544120495-17438-6-git-send-email-will.deacon@arm.com Signed-off-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Toshi Kani <toshi.kani@hpe.com> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Hocko <mhocko@suse.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 13b80361d9f5..b6f5aa52ac67 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1043,6 +1043,11 @@ int pud_free_pmd_page(pud_t *pudp, unsigned long addr)
return 1;
+int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
+ return 0; /* Don't attempt a block mapping */
int arch_add_memory(int nid, u64 start, u64 size, struct vmem_altmap *altmap,
bool want_memblock)
diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
index e95a7d6ac8f8..b0284eab14dc 100644
--- a/arch/x86/mm/pgtable.c
+++ b/arch/x86/mm/pgtable.c
@@ -794,6 +794,14 @@ int pmd_clear_huge(pmd_t *pmd)
return 0;
+ * Until we support 512GB pages, skip them in the vmap area.
+ */
+int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
+ return 0;
#ifdef CONFIG_X86_64
* pud_free_pmd_page - Clear pud entry and free pmd page.