3.16.52-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Borislav Petkov <[email protected]> commit bfc1168de949cd3e9ca18c3480b5085deff1ea7c upstream. Some F14h machines have an erratum which, "under a highly specific and detailed set of internal timing conditions" can lead to skipping instructions and RIP corruption. Add the fix for those machines when their BIOS doesn't apply it or there simply isn't BIOS update for them. Tested-by: <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Sherry Hurwitz <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Yazen Ghannam <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Link: https://bugzilla.kernel.org/show_bug.cgi?id=197285 [ Added pr_info() that we activated the workaround. ] Signed-off-by: Ingo Molnar <[email protected]> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <[email protected]> --- arch/x86/kernel/amd_nb.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) --- a/arch/x86/kernel/amd_nb.c +++ b/arch/x86/kernel/amd_nb.c @@ -18,6 +18,8 @@ static u32 *flush_words; +#define PCI_DEVICE_ID_AMD_CNB17H_F4 0x1704 + const struct pci_device_id amd_nb_misc_ids[] = { { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) }, { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) }, @@ -28,6 +30,7 @@ const struct pci_device_id amd_nb_misc_i { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) }, { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) }, { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) }, + { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F3) }, {} }; EXPORT_SYMBOL(amd_nb_misc_ids); @@ -39,6 +42,7 @@ static const struct pci_device_id amd_nb { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) }, { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) }, { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) }, + { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CNB17H_F4) }, {} }; @@ -285,6 +289,41 @@ void amd_flush_garts(void) } EXPORT_SYMBOL_GPL(amd_flush_garts); +static void __fix_erratum_688(void *info) +{ +#define MSR_AMD64_IC_CFG 0xC0011021 + + msr_set_bit(MSR_AMD64_IC_CFG, 3); + msr_set_bit(MSR_AMD64_IC_CFG, 14); +} + +/* Apply erratum 688 fix so machines without a BIOS fix work. */ +static __init void fix_erratum_688(void) +{ + struct pci_dev *F4; + u32 val; + + if (boot_cpu_data.x86 != 0x14) + return; + + if (!amd_northbridges.num) + return; + + F4 = node_to_amd_nb(0)->link; + if (!F4) + return; + + if (pci_read_config_dword(F4, 0x164, &val)) + return; + + if (val & BIT(2)) + return; + + on_each_cpu(__fix_erratum_688, NULL, 0); + + pr_info("x86/cpu/AMD: CPU erratum 688 worked around\n"); +} + static __init int init_amd_nbs(void) { int err = 0; @@ -297,6 +336,8 @@ static __init int init_amd_nbs(void) if (amd_cache_gart() < 0) pr_notice("Cannot initialize GART flush words, GART support disabled\n"); + fix_erratum_688(); + return err; }
