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| author | Ian Wisbon <ian.wisbon@timesys.com> | 2011-02-15 15:53:51 -0500 |
|---|---|---|
| committer | Ian Wisbon <ian.wisbon@timesys.com> | 2011-02-15 15:53:51 -0500 |
| commit | dfdbf3f6e2d279f2a46ed95614cb4bf07657394d (patch) | |
| tree | 2cc05669c5d3e47f7d4b28e31076b6dc6e771f36 /arch/x86/pci/i386.c | |
| parent | effff5718c380983788fe6c380671c18e15ac7c2 (diff) | |
Digi del-5.6 Complete2.6.31-digi-201102151558
Diffstat (limited to 'arch/x86/pci/i386.c')
| -rw-r--r-- | arch/x86/pci/i386.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c index 52e62e57fedd..5da8792b48a4 100644 --- a/arch/x86/pci/i386.c +++ b/arch/x86/pci/i386.c @@ -282,6 +282,15 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, return -EINVAL; prot = pgprot_val(vma->vm_page_prot); + + /* + * Return error if pat is not enabled and write_combine is requested. + * Caller can followup with UC MINUS request and add a WC mtrr if there + * is a free mtrr slot. + */ + if (!pat_enabled && write_combine) + return -EINVAL; + if (pat_enabled && write_combine) prot |= _PAGE_CACHE_WC; else if (pat_enabled || boot_cpu_data.x86 > 3) |