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author=?UTF-8?q?Christian=20K=C3=B6nig?= <ckoenig.leichtzumerken@gmail.com>2018-01-11 14:23:30 +0100
committerBjorn Helgaas <helgaas@kernel.org>2018-01-11 19:01:58 +0100
commit03a551734cfc2b93f83950a595974e3c9cbd82fd (patch)
tree51e78945b9696c8ec7219ed412ee75607e4a11c8 /arch/x86
parentx86/PCI: Add "pci=big_root_window" option for AMD 64-bit windows (diff)
downloadlinux-03a551734cfc2b93f83950a595974e3c9cbd82fd.tar.xz
linux-03a551734cfc2b93f83950a595974e3c9cbd82fd.zip
x86/PCI: Move and shrink AMD 64-bit window to avoid conflict
Avoid problems with BIOS implementations which don't report all used resources to the OS by only allocating a 256GB window directly below the hardware limit (from the BKDG, sec 2.4.6). Fixes a silent reboot loop reported by Aaro Koskinen <aaro.koskinen@iki.fi> on an AMD-based MSI MS-7699/760GA-P43(FX) system. This was apparently caused by RAM or other unreported hardware that conflicted with the new window. Link: https://support.amd.com/TechDocs/49125_15h_Models_30h-3Fh_BKDG.pdf Link: https://lkml.kernel.org/r/20180105220412.fzpwqe4zljdawr36@darkstar.musicnaut.iki.fi Fixes: fa564ad96366 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)") Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Christian König <christian.koenig@amd.com> [bhelgaas: changelog, comment, Fixes:] Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/pci/fixup.c22
1 files changed, 12 insertions, 10 deletions
diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c
index 8bad19c7473d..f6a26e3cb476 100644
--- a/arch/x86/pci/fixup.c
+++ b/arch/x86/pci/fixup.c
@@ -662,10 +662,11 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2033, quirk_no_aersid);
*/
static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
{
- unsigned i;
u32 base, limit, high;
- struct resource *res, *conflict;
struct pci_dev *other;
+ struct resource *res;
+ unsigned i;
+ int r;
if (!(pci_probe & PCI_BIG_ROOT_WINDOW))
return;
@@ -702,19 +703,20 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev)
if (!res)
return;
+ /*
+ * Allocate a 256GB window directly below the 0xfd00000000 hardware
+ * limit (see AMD Family 15h Models 30h-3Fh BKDG, sec 2.4.6).
+ */
res->name = "PCI Bus 0000:00";
res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM |
IORESOURCE_MEM_64 | IORESOURCE_WINDOW;
- res->start = 0x100000000ull;
+ res->start = 0xbd00000000ull;
res->end = 0xfd00000000ull - 1;
- /* Just grab the free area behind system memory for this */
- while ((conflict = request_resource_conflict(&iomem_resource, res))) {
- if (conflict->end >= res->end) {
- kfree(res);
- return;
- }
- res->start = conflict->end + 1;
+ r = request_resource(&iomem_resource, res);
+ if (r) {
+ kfree(res);
+ return;
}
dev_info(&dev->dev, "adding root bus resource %pR (tainting kernel)\n",