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authorWill Deacon <will.deacon@arm.com>2018-12-28 00:37:49 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-28 12:11:50 -0800
commit36ddc5a78c878e9b10c323d2fe88b0dae2f487eb (patch)
tree49e1698683500be2c4b481053af814a75922a755 /lib
parent48e178ab0d630b8b60deca64b22b22e68818777e (diff)
lib/ioremap: ensure phys_addr actually corresponds to a physical address
The current ioremap() code uses a phys_addr variable at each level of page table, which is confusingly offset by subtracting the base virtual address being mapped so that adding the current virtual address back on when iterating through the page table entries gives back the corresponding physical address. This is fairly confusing and results in all users of phys_addr having to add the current virtual address back on. Instead, this patch just updates phys_addr when iterating over the page table entries, ensuring that it's always up-to-date and doesn't require explicit offsetting. Link: http://lkml.kernel.org/r/1544120495-17438-5-git-send-email-will.deacon@arm.com Signed-off-by: Will Deacon <will.deacon@arm.com> Tested-by: Sean Christopherson <sean.j.christopherson@intel.com> Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.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: Sean Christopherson <sean.j.christopherson@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> 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.c28
1 files changed, 12 insertions, 16 deletions
diff --git a/lib/ioremap.c b/lib/ioremap.c
index 6c72764af19c..10d7c5485c39 100644
--- a/lib/ioremap.c
+++ b/lib/ioremap.c
@@ -101,19 +101,18 @@ static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
pmd_t *pmd;
unsigned long next;
- phys_addr -= addr;
pmd = pmd_alloc(&init_mm, pud, addr);
if (!pmd)
return -ENOMEM;
do {
next = pmd_addr_end(addr, end);
- if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr + addr, prot))
+ if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot))
continue;
- if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
+ if (ioremap_pte_range(pmd, addr, next, phys_addr, prot))
return -ENOMEM;
- } while (pmd++, addr = next, addr != end);
+ } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
return 0;
}
@@ -142,19 +141,18 @@ static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
pud_t *pud;
unsigned long next;
- phys_addr -= addr;
pud = pud_alloc(&init_mm, p4d, addr);
if (!pud)
return -ENOMEM;
do {
next = pud_addr_end(addr, end);
- if (ioremap_try_huge_pud(pud, addr, next, phys_addr + addr, prot))
+ if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot))
continue;
- if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
+ if (ioremap_pmd_range(pud, addr, next, phys_addr, prot))
return -ENOMEM;
- } while (pud++, addr = next, addr != end);
+ } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
return 0;
}
@@ -164,7 +162,6 @@ static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
p4d_t *p4d;
unsigned long next;
- phys_addr -= addr;
p4d = p4d_alloc(&init_mm, pgd, addr);
if (!p4d)
return -ENOMEM;
@@ -173,14 +170,14 @@ static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
if (ioremap_p4d_enabled() &&
((next - addr) == P4D_SIZE) &&
- IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
- if (p4d_set_huge(p4d, phys_addr + addr, prot))
+ IS_ALIGNED(phys_addr, P4D_SIZE)) {
+ if (p4d_set_huge(p4d, phys_addr, prot))
continue;
}
- if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
+ if (ioremap_pud_range(p4d, addr, next, phys_addr, prot))
return -ENOMEM;
- } while (p4d++, addr = next, addr != end);
+ } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
return 0;
}
@@ -196,14 +193,13 @@ int ioremap_page_range(unsigned long addr,
BUG_ON(addr >= end);
start = addr;
- phys_addr -= addr;
pgd = pgd_offset_k(addr);
do {
next = pgd_addr_end(addr, end);
- err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
+ err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot);
if (err)
break;
- } while (pgd++, addr = next, addr != end);
+ } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
flush_cache_vmap(start, end);

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