On Thu, Jan 11, 2018 at 03:51:45PM +0100, Christian König wrote: > Am 11.01.2018 um 15:21 schrieb Bjorn Helgaas: > >On Thu, Jan 11, 2018 at 02:23:30PM +0100, Christian König wrote: > >>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. > >> > >>For the full hardware documentation see: > >>https://support.amd.com/TechDocs/49125_15h_Models_30h-3Fh_BKDG.pdf > >If you can supply a section number, I'll add it here. That spec is 700 > >pages, so a hint would be useful. > > Sorry, had to search for that as well. That is noted in section > "2.4.6 System Address Map". > > Do you want to add that or should I resend the patch? I added it and put both patches on my for-linus branch for v4.15, thanks! > >>Fixes a silent reboot loop reported by Aaro Koskinen <aaro.koskinen@xxxxxx> on > >>an AMD-based MSI MS-7699/760GA-P43(FX) system. > >> > >>v2: cleanup code a bit more, update comment and explain the hw limit > >>v3: improve commit message > >> > >>Link: https://lkml.kernel.org/r/20180105220412.fzpwqe4zljdawr36@xxxxxxxxxxxxxxxxxxxxxxxxx > >>Reported-by: Aaro Koskinen <aaro.koskinen@xxxxxx> > >>Signed-off-by: Christian König <christian.koenig@xxxxxxx> > >>--- > >> arch/x86/pci/fixup.c | 19 +++++++++---------- > >> 1 file changed, 9 insertions(+), 10 deletions(-) > >> > >>diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c > >>index a91280da2ea1..9c1c98d7e3a7 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 +703,17 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) > >> if (!res) > >> return; > >>+ /* Allocate a 256GB window directly below the 0xfd00000000 hw limit */ > >> 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\n", res); > >>-- > >>2.11.0 > >> >
