Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

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

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

arch/x86/pci/fixup.c

+12 −10
Original line number Original line 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)

static void pci_amd_enable_64bit_bar(struct pci_dev *dev)

{

{

	unsigned i;

	u32 base, limit, high;

	u32 base, limit, high;

	struct resource *res, *conflict;

	struct pci_dev *other;

	struct pci_dev *other;

	struct resource *res;

	unsigned i;

	int r;





	if (!(pci_probe & PCI_BIG_ROOT_WINDOW))

	if (!(pci_probe & PCI_BIG_ROOT_WINDOW))

		return;

		return;
@@ -702,20 +703,21 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) 
	if (!res)

	if (!res)

		return;

		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->name = "PCI Bus 0000:00";

	res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM |

	res->flags = IORESOURCE_PREFETCH | IORESOURCE_MEM |

		IORESOURCE_MEM_64 | IORESOURCE_WINDOW;

		IORESOURCE_MEM_64 | IORESOURCE_WINDOW;

	res->start = 0x100000000ull;

	res->start = 0xbd00000000ull;

	res->end = 0xfd00000000ull - 1;

	res->end = 0xfd00000000ull - 1;





	/* Just grab the free area behind system memory for this */

	r = request_resource(&iomem_resource, res);

	while ((conflict = request_resource_conflict(&iomem_resource, res))) {

	if (r) {

		if (conflict->end >= res->end) {

		kfree(res);

		kfree(res);

		return;

		return;

	}

	}

		res->start = conflict->end + 1;

	}





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

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

		 res);

		 res);