1 files changed, 23 insertions, 0 deletions

diff --git a/arch/x86/pci/pcbios.c b/arch/x86/pci/pcbios.c
index 2492d165096a..a5f7d0d63de0 100644
--- a/arch/x86/pci/pcbios.c
+++ b/arch/x86/pci/pcbios.c
@@ -9,6 +9,7 @@
 #include <linux/uaccess.h>
 #include <asm/pci_x86.h>
 #include <asm/pci-functions.h>
+#include <asm/cacheflush.h>
 
 /* BIOS32 signature: "_32_" */
 #define BIOS32_SIGNATURE        (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
@@ -25,6 +26,27 @@
 #define PCIBIOS_HW_TYPE1_SPEC           0x10
 #define PCIBIOS_HW_TYPE2_SPEC           0x20
 
+int pcibios_enabled;
+
+/* According to the BIOS specification at:
+ * http://members.datafast.net.au/dft0802/specs/bios21.pdf, we could
+ * restrict the x zone to some pages and make it ro. But this may be
+ * broken on some bios, complex to handle with static_protections.
+ * We could make the 0xe0000-0x100000 range rox, but this can break
+ * some ISA mapping.
+ *
+ * So we let's an rw and x hole when pcibios is used. This shouldn't
+ * happen for modern system with mmconfig, and if you don't want it
+ * you could disable pcibios...
+ */
+static inline void set_bios_x(void)
+{
+        pcibios_enabled = 1;
+        set_memory_x(PAGE_OFFSET + BIOS_BEGIN, (BIOS_END - BIOS_BEGIN) >> PAGE_SHIFT);
+        if (__supported_pte_mask & _PAGE_NX)
+                printk(KERN_INFO "PCI : PCI BIOS aera is rw and x. Use pci=nobios if you want it NX.\n");
+}
+
 /*
  * This is the standard structure used to identify the entry point
  * to the BIOS32 Service Directory, as documented in
@@ -332,6 +354,7 @@ static struct pci_raw_ops * __devinit pci_find_bios(void)
                         DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
                                         bios32_entry);
                         bios32_indirect.address = bios32_entry + PAGE_OFFSET;
+                        set_bios_x();
                         if (check_pcibios())
                                 return &pci_bios_access;
                 }