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| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2009-07-10 18:57:34 +0200 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-08-27 00:41:10 +0200 |
| commit | 9fd126bc742f74a95d2ba610247712ff05da02fe (patch) | |
| tree | 2be99f0b80d6f5d07d2cff6bfddbb1b9313f026c /arch/x86 | |
| parent | x86, pat: ioremap to follow same PAT restrictions as other PAT users (diff) | |
| download | linux-9fd126bc742f74a95d2ba610247712ff05da02fe.tar.xz linux-9fd126bc742f74a95d2ba610247712ff05da02fe.zip | |
x86, pat: New i/f for driver to request memtype for IO regions
Add new routines to request memtype for IO regions. This will currently
be a backend for io_mapping_* routines. But, it can also be made available
to drivers directly in future, in case it is needed.
reserve interface reserves the memory, makes sure we have a compatible
memory type available and keeps the identity map in sync when needed.
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/pat.h | 5 | ||||
| -rw-r--r-- | arch/x86/mm/pat.c | 49 |
2 files changed, 54 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pat.h b/arch/x86/include/asm/pat.h index 7af14e512f97..e2c1668dde7a 100644 --- a/arch/x86/include/asm/pat.h +++ b/arch/x86/include/asm/pat.h @@ -19,4 +19,9 @@ extern int free_memtype(u64 start, u64 end); extern int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flag); +int io_reserve_memtype(resource_size_t start, resource_size_t end, + unsigned long *type); + +void io_free_memtype(resource_size_t start, resource_size_t end); + #endif /* _ASM_X86_PAT_H */ diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index d5af2792d2fd..82d097ce3091 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -498,6 +498,55 @@ int free_memtype(u64 start, u64 end) } +/** + * io_reserve_memtype - Request a memory type mapping for a region of memory + * @start: start (physical address) of the region + * @end: end (physical address) of the region + * @type: A pointer to memtype, with requested type. On success, requested + * or any other compatible type that was available for the region is returned + * + * On success, returns 0 + * On failure, returns non-zero + */ +int io_reserve_memtype(resource_size_t start, resource_size_t end, + unsigned long *type) +{ + unsigned long req_type = *type; + unsigned long new_type; + int ret; + + WARN_ON_ONCE(iomem_map_sanity_check(start, end - start)); + + ret = reserve_memtype(start, end, req_type, &new_type); + if (ret) + goto out_err; + + if (!is_new_memtype_allowed(req_type, new_type)) + goto out_free; + + if (kernel_map_sync_memtype(start, end - start, new_type) < 0) + goto out_free; + + *type = new_type; + return 0; + +out_free: + free_memtype(start, end); + ret = -EBUSY; +out_err: + return ret; +} + +/** + * io_free_memtype - Release a memory type mapping for a region of memory + * @start: start (physical address) of the region + * @end: end (physical address) of the region + */ +void io_free_memtype(resource_size_t start, resource_size_t end) +{ + free_memtype(start, end); +} + pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot) { |