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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 /lib
parent36ddc5a78c878e9b10c323d2fe88b0dae2f487eb (diff)
downloadlinux-stericsson-8e2d43405b22e98cf5f3730c1829ec1fdbe17ae7.tar.gz
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 'lib')
-rw-r--r--lib/ioremap.c27
1 files changed, 21 insertions, 6 deletions
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 10d7c5485c39..063213685563 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -156,6 +156,25 @@ static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
return 0;
}
+static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
+ unsigned long end, phys_addr_t phys_addr,
+ pgprot_t prot)
+{
+ if (!ioremap_p4d_enabled())
+ return 0;
+
+ if ((end - addr) != P4D_SIZE)
+ return 0;
+
+ if (!IS_ALIGNED(phys_addr, P4D_SIZE))
+ return 0;
+
+ if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
+ return 0;
+
+ return p4d_set_huge(p4d, phys_addr, prot);
+}
+
static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
@@ -168,12 +187,8 @@ static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
do {
next = p4d_addr_end(addr, end);
- if (ioremap_p4d_enabled() &&
- ((next - addr) == P4D_SIZE) &&
- IS_ALIGNED(phys_addr, P4D_SIZE)) {
- if (p4d_set_huge(p4d, phys_addr, prot))
- continue;
- }
+ if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot))
+ continue;
if (ioremap_pud_range(p4d, addr, next, phys_addr, prot))
return -ENOMEM;