x86: PAT phys_mem_access_prot_allowed for dev/mem mmap

[linux-2.6] / arch / x86 / mm / pat.c

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 57a2af36d6ee68f0320c9218610cbe4d6dcfe47d..64cc0c18233ed2831e6a368f379c5bab7dabb993 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -40,13 +40,8 @@ static int pat_known_cpu(void)
        if (!pat_wc_enabled)
                return 0;
 
-       if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
-           (boot_cpu_data.x86 == 0xF ||
-            (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model >= 15))) {
-               if (cpu_has_pat) {
-                       return 1;
-               }
-       }
+       if (cpu_has_pat)
+               return 1;
 
        pat_wc_enabled = 0;
        printk(KERN_INFO "CPU and/or kernel does not support PAT.\n");
@@ -424,3 +419,42 @@ int free_memtype(u64 start, u64 end)
        return err;
 }
 
+
+/* /dev/mem interface. Use the previous mapping */
+pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+                               unsigned long size, pgprot_t vma_prot)
+{
+       return vma_prot;
+}
+
+int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
+                               unsigned long size, pgprot_t *vma_prot)
+{
+
+       if (file->f_flags & O_SYNC) {
+               *vma_prot = pgprot_noncached(*vma_prot);
+               return 1;
+       }
+
+#ifdef CONFIG_X86_32
+       /*
+        * On the PPro and successors, the MTRRs are used to set
+        * memory types for physical addresses outside main memory,
+        * so blindly setting UC or PWT on those pages is wrong.
+        * For Pentiums and earlier, the surround logic should disable
+        * caching for the high addresses through the KEN pin, but
+        * we maintain the tradition of paranoia in this code.
+        */
+       if (!pat_wc_enabled &&
+           ! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
+               test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
+               test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
+               test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) &&
+          (pfn << PAGE_SHIFT) >= __pa(high_memory)) {
+               *vma_prot = pgprot_noncached(*vma_prot);
+               return 1;
+       }
+#endif
+
+       return 1;
+}