path: root/arch/ia64/pci
diff options
authorBjorn Helgaas <bjorn.helgaas@hp.com>2006-05-05 17:19:50 -0600
committerTony Luck <tony.luck@intel.com>2006-05-08 16:32:05 -0700
commit32e62c636a728cb39c0b3bd191286f2ca65d4028 (patch)
tree656454a01e720819103c172daae15b5f2fd85d68 /arch/ia64/pci
parent6810b548b25114607e0814612d84125abccc0a4f (diff)
[IA64] rework memory attribute aliasing
This closes a couple holes in our attribute aliasing avoidance scheme: - The current kernel fails mmaps of some /dev/mem MMIO regions because they don't appear in the EFI memory map. This keeps X from working on the Intel Tiger box. - The current kernel allows UC mmap of the 0-1MB region of /sys/.../legacy_mem even when the chipset doesn't support UC access. This causes an MCA when starting X on HP rx7620 and rx8620 boxes in the default configuration. There's more detail in the Documentation/ia64/aliasing.txt file this adds, but the general idea is that if a region might be covered by a granule-sized kernel identity mapping, any access via /dev/mem or mmap must use the same attribute as the identity mapping. Otherwise, we fall back to using an attribute that is supported according to the EFI memory map, or to using UC if the EFI memory map doesn't mention the region. Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/pci')
1 files changed, 15 insertions, 2 deletions
diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index ab829a22f8a..30d148f3404 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -645,18 +645,31 @@ char *ia64_pci_get_legacy_mem(struct pci_bus *bus)
pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma)
+ unsigned long size = vma->vm_end - vma->vm_start;
+ pgprot_t prot;
char *addr;
+ /*
+ * Avoid attribute aliasing. See Documentation/ia64/aliasing.txt
+ * for more details.
+ */
+ if (!valid_mmap_phys_addr_range(vma->vm_pgoff << PAGE_SHIFT, size))
+ return -EINVAL;
+ prot = phys_mem_access_prot(NULL, vma->vm_pgoff, size,
+ vma->vm_page_prot);
+ if (pgprot_val(prot) != pgprot_val(pgprot_noncached(vma->vm_page_prot)))
+ return -EINVAL;
addr = pci_get_legacy_mem(bus);
if (IS_ERR(addr))
return PTR_ERR(addr);
vma->vm_pgoff += (unsigned long)addr >> PAGE_SHIFT;
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ vma->vm_page_prot = prot;
vma->vm_flags |= (VM_SHM | VM_RESERVED | VM_IO);
if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
- vma->vm_end - vma->vm_start, vma->vm_page_prot))
+ size, vma->vm_page_prot))
return -EAGAIN;
return 0;