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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-02-22 15:02:07 +0100 |
|---|---|---|
| committer | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2016-04-04 10:26:41 +0200 |
| commit | c269cba35b061181bc23c470809c00e8f71e535a (patch) | |
| tree | 5b34de143f15b6eb1b786394c45fa8012d4397a9 | |
| parent | 7769aea2a27db8f12859dcecce37a3da44ab588b (diff) | |
| download | linux-rt-c269cba35b061181bc23c470809c00e8f71e535a.tar.gz | |
memremap: add arch specific hook for MEMREMAP_WB mappings
Currently, the memremap code serves MEMREMAP_WB mappings directly from
the kernel direct mapping, unless the region is in high memory, in which
case it falls back to using ioremap_cache(). However, the semantics of
ioremap_cache() are not unambiguously defined, and on ARM, it will
actually result in a mapping type that differs from the attributes used
for the linear mapping, and for this reason, the ioremap_cache() call
fails if the region is part of the memory managed by the kernel.
So instead, implement an optional hook 'arch_memremap_wb' whose default
implementation calls ioremap_cache() as before, but which can be
overridden by the architecture to do what is appropriate for it.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
| -rw-r--r-- | kernel/memremap.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c index a6d382312e6f..017532193fb1 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -27,6 +27,13 @@ __weak void __iomem *ioremap_cache(resource_size_t offset, unsigned long size) } #endif +#ifndef arch_memremap_wb +static void *arch_memremap_wb(resource_size_t offset, unsigned long size) +{ + return (__force void *)ioremap_cache(offset, size); +} +#endif + static void *try_ram_remap(resource_size_t offset, size_t size) { unsigned long pfn = PHYS_PFN(offset); @@ -34,7 +41,7 @@ static void *try_ram_remap(resource_size_t offset, size_t size) /* In the simple case just return the existing linear address */ if (pfn_valid(pfn) && !PageHighMem(pfn_to_page(pfn))) return __va(offset); - return NULL; /* fallback to ioremap_cache */ + return NULL; /* fallback to arch_memremap_wb */ } /** @@ -90,7 +97,7 @@ void *memremap(resource_size_t offset, size_t size, unsigned long flags) if (is_ram == REGION_INTERSECTS) addr = try_ram_remap(offset, size); if (!addr) - addr = ioremap_cache(offset, size); + addr = arch_memremap_wb(offset, size); } /* |