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| author | Will Deacon <will.deacon@arm.com> | 2018-12-28 00:37:53 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-28 12:11:50 -0800 |
| commit | 8e2d43405b22e98cf5f3730c1829ec1fdbe17ae7 (patch) | |
| tree | c30cf15a54d92a9e56c9c2c1e5fd9455e816b432 /lib | |
| parent | 36ddc5a78c878e9b10c323d2fe88b0dae2f487eb (diff) | |
| download | lwn-8e2d43405b22e98cf5f3730c1829ec1fdbe17ae7.tar.gz lwn-8e2d43405b22e98cf5f3730c1829ec1fdbe17ae7.zip | |
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.c | 27 |
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; |