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| author | Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | 2009-07-10 09:57:41 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-08-26 15:41:35 -0700 |
| commit | d886c73cd4cf02a71e1650cbcb6176799d78aac1 (patch) | |
| tree | b7bf968f5d9661e4d6fd56b35386556779194df1 /arch/x86/mm/pat.c | |
| parent | 1087637616dd5e96d834164ea462aed6159d039b (diff) | |
| download | op-kernel-dev-d886c73cd4cf02a71e1650cbcb6176799d78aac1.zip op-kernel-dev-d886c73cd4cf02a71e1650cbcb6176799d78aac1.tar.gz | |
x86, pat: Sanity check remap_pfn_range for RAM region
Add sanity check for remap_pfn_range of RAM regions using
lookup_memtype(). Previously, we did not have anyway to get the type of
RAM memory regions as they were tracked using a single bit in
page_struct (WB, nonWB). Now we can get the actual type from page struct
(WB, WC, UC_MINUS) and make sure the requester gets that type.
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/mm/pat.c')
| -rw-r--r-- | arch/x86/mm/pat.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c index b629f75..a6cace0 100644 --- a/arch/x86/mm/pat.c +++ b/arch/x86/mm/pat.c @@ -783,11 +783,29 @@ static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, is_ram = pat_pagerange_is_ram(paddr, paddr + size); /* - * reserve_pfn_range() doesn't support RAM pages. Maintain the current - * behavior with RAM pages by returning success. + * reserve_pfn_range() for RAM pages. We do not refcount to keep + * track of number of mappings of RAM pages. We can assert that + * the type requested matches the type of first page in the range. */ - if (is_ram != 0) + if (is_ram) { + if (!pat_enabled) + return 0; + + flags = lookup_memtype(paddr); + if (want_flags != flags) { + printk(KERN_WARNING + "%s:%d map pfn RAM range req %s for %Lx-%Lx, got %s\n", + current->comm, current->pid, + cattr_name(want_flags), + (unsigned long long)paddr, + (unsigned long long)(paddr + size), + cattr_name(flags)); + *vma_prot = __pgprot((pgprot_val(*vma_prot) & + (~_PAGE_CACHE_MASK)) | + flags); + } return 0; + } ret = reserve_memtype(paddr, paddr + size, want_flags, &flags); if (ret) |
