x86/PCI: Move and shrink AMD 64-bit window to avoid conflict (03a55173) · Commits · 戴 / test

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: ("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>

arch/x86/pci/fixup.c

+12 −10

Original line number	Diff line number	Diff line
		@@ -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;
		@@ -702,20 +703,21 @@ 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) {
		r = request_resource(&iomem_resource, res);
		if (r) {
		kfree(res);
		return;
		}
		res->start = conflict->end + 1;
		}

		dev_info(&dev->dev, "adding root bus resource %pR (tainting kernel)\n",
		res);

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