On Fri, 5 May 2006 17:19:50 -0600 Bjorn Helgaas <bjorn.helgaas@xxxxxx> wrote: > 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@xxxxxx> > At memory hotplug, efi information cannot be updated. In -mm kernel, hot added memory is registed to /proc/iomem (iomem_resouce). Can't we able to write kern_mem_attribute() by using kernel/resouce.c ? (add new flag if needed..) Now, efi_initialize_iomem_resources() already registers efi information to iomem_resource. -Kame - : send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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