Commit 03a55173 authored by =?UTF-8?q?Christian=20K=C3=B6nig?='s avatar =?UTF-8?q?Christian=20K=C3=B6nig?= Committed by Bjorn Helgaas

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: fa564ad9 ("x86/PCI: Enable a 64bit BAR on AMD Family 15h (Models 00-1f, 30-3f, 60-7f)")
Reported-by: default avatarAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
[bhelgaas: changelog, comment, Fixes:]
Signed-off-by: default avatarBjorn Helgaas <helgaas@kernel.org>
parent f32ab754
......@@ -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",
......
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