diff options
| author | =?UTF-8?q?Christian=20K=C3=B6nig?= <ckoenig.leichtzumerken@gmail.com> | 2018-01-11 14:23:29 +0100 |
|---|---|---|
| committer | Bjorn Helgaas <helgaas@kernel.org> | 2018-01-11 11:22:39 -0600 |
| commit | f32ab7547161b9fa7ebfbc4f18ea1eb3fd49fe25 (patch) | |
| tree | f806a04056ffadf4bdc92e4d70e1ff1488c713b0 /arch/x86/pci | |
| parent | 1291a0d5049dbc06baaaf66a9ff3f53db493b19b (diff) | |
x86/PCI: Add "pci=big_root_window" option for AMD 64-bit windows
Only try to enable a 64-bit window on AMD CPUs when "pci=big_root_window"
is specified.
This taints the kernel because the new 64-bit window uses address space we
don't know anything about, and it may contain unreported devices or memory
that would conflict with the window.
The pci_amd_enable_64bit_bar() quirk that enables the window is specific to
AMD CPUs. The generic solution would be to have the firmware enable the
window and describe it in the host bridge's _CRS method, or at least
describe it in the _PRS method so the OS would have the option of enabling
it.
Signed-off-by: Christian König <christian.koenig@amd.com>
[bhelgaas: changelog, extend doc, mention taint in dmesg]
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>
Diffstat (limited to 'arch/x86/pci')
| -rw-r--r-- | arch/x86/pci/common.c | 5 | ||||
| -rw-r--r-- | arch/x86/pci/fixup.c | 7 |
2 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c index 7a5350d08cef..563049c483a1 100644 --- a/arch/x86/pci/common.c +++ b/arch/x86/pci/common.c @@ -594,6 +594,11 @@ char *__init pcibios_setup(char *str) } else if (!strcmp(str, "nocrs")) { pci_probe |= PCI_ROOT_NO_CRS; return NULL; +#ifdef CONFIG_PHYS_ADDR_T_64BIT + } else if (!strcmp(str, "big_root_window")) { + pci_probe |= PCI_BIG_ROOT_WINDOW; + return NULL; +#endif } else if (!strcmp(str, "earlydump")) { pci_early_dump_regs = 1; return NULL; diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c index e663d6bf1328..8bad19c7473d 100644 --- a/arch/x86/pci/fixup.c +++ b/arch/x86/pci/fixup.c @@ -667,6 +667,9 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) struct resource *res, *conflict; struct pci_dev *other; + if (!(pci_probe & PCI_BIG_ROOT_WINDOW)) + return; + /* Check that we are the only device of that type */ other = pci_get_device(dev->vendor, dev->device, NULL); if (other != dev || @@ -714,7 +717,9 @@ static void pci_amd_enable_64bit_bar(struct pci_dev *dev) res->start = conflict->end + 1; } - dev_info(&dev->dev, "adding root bus resource %pR\n", res); + dev_info(&dev->dev, "adding root bus resource %pR (tainting kernel)\n", + res); + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); base = ((res->start >> 8) & AMD_141b_MMIO_BASE_MMIOBASE_MASK) | AMD_141b_MMIO_BASE_RE_MASK | AMD_141b_MMIO_BASE_WE_MASK; |