diff options
| author | Ingo Molnar <mingo@elte.hu> | 2008-02-14 23:30:20 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-02-14 23:30:20 +0100 |
| commit | 184652eb6f68050af48a2ce3d5cf0537c208bee2 (patch) | |
| tree | 1362a91c254120b68e324f58cc2715139bba53a5 | |
| parent | 3223f59f9cd9d69a4344eeac8b16a262c5f373f1 (diff) | |
x86: fix gart_iommu_init()
When the GART table is unmapped from the kernel direct mappings
during early bootup, make sure we have no leftover cachelines in it.
Note: the clflush done by set_memory_np() was not enough, because
clflush does not work on unmapped pages.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| -rw-r--r-- | arch/x86/kernel/pci-gart_64.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c index 65f6acb025c..faf3229f8fb 100644 --- a/arch/x86/kernel/pci-gart_64.c +++ b/arch/x86/kernel/pci-gart_64.c @@ -749,6 +749,15 @@ void __init gart_iommu_init(void) */ set_memory_np((unsigned long)__va(iommu_bus_base), iommu_size >> PAGE_SHIFT); + /* + * Tricky. The GART table remaps the physical memory range, + * so the CPU wont notice potential aliases and if the memory + * is remapped to UC later on, we might surprise the PCI devices + * with a stray writeout of a cacheline. So play it sure and + * do an explicit, full-scale wbinvd() _after_ having marked all + * the pages as Not-Present: + */ + wbinvd(); /* * Try to workaround a bug (thanks to BenH) |