[PATCH V2 2/4] x86/mce, PCI: Provide quirks to identify Xeon models with machine check recovery

["Luck, Tony" <tony.luck@intel.com>]

Each Xeon includes a number of capability registers in PCI space
that describe some features not enumerated by CPUID.

Use these to determine that we are running on a model that can recover
from machine checks. Hooks for Ivybridge ... Skylake provided.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---

V2:
Boris & Linus: move quirks from generic code to arch/x86
Ingo: Use arch/x86/kernel/early-quirks.c? Can't do that. It only looks at
      bridge devices on top level bus. The devices I need are deeper in
      the hierarchy on per-socket buses.
No changes to parts 1, 3, 4.

 arch/x86/include/asm/string_64.h |  3 +++
 arch/x86/kernel/cpu/mcheck/mce.c |  7 +++++++
 arch/x86/kernel/quirks.c         | 31 +++++++++++++++++++++++++++++++
 3 files changed, 41 insertions(+)

diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
index 90dbbd9666d4..877a1dfbf770 100644
--- a/arch/x86/include/asm/string_64.h
+++ b/arch/x86/include/asm/string_64.h
@@ -2,6 +2,7 @@
 #define _ASM_X86_STRING_64_H
 
 #ifdef __KERNEL__
+#include <linux/jump_label.h>
 
 /* Written 2002 by Andi Kleen */
 
@@ -78,6 +79,8 @@ int strcmp(const char *cs, const char *ct);
 #define memset(s, c, n) __memset(s, c, n)
 #endif
 
+DECLARE_STATIC_KEY_FALSE(mcsafe_key);
+
 /**
  * memcpy_mcsafe - copy memory with indication if a machine check happened
  *
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 79d8ec849468..c192fabc3d76 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -41,6 +41,7 @@
 #include <linux/debugfs.h>
 #include <linux/irq_work.h>
 #include <linux/export.h>
+#include <linux/jump_label.h>
 
 #include <asm/processor.h>
 #include <asm/traps.h>
@@ -2676,8 +2677,14 @@ static int __init mcheck_debugfs_init(void)
 static int __init mcheck_debugfs_init(void) { return -EINVAL; }
 #endif
 
+DEFINE_STATIC_KEY_FALSE(mcsafe_key);
+EXPORT_SYMBOL_GPL(mcsafe_key);
+
 static int __init mcheck_late_init(void)
 {
+	if (mca_cfg.recovery)
+		static_branch_inc(&mcsafe_key);
+
 	mcheck_debugfs_init();
 
 	/*
diff --git a/arch/x86/kernel/quirks.c b/arch/x86/kernel/quirks.c
index cc457ff818ad..51402a7e4ca6 100644
--- a/arch/x86/kernel/quirks.c
+++ b/arch/x86/kernel/quirks.c
@@ -626,3 +626,34 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3,
 			amd_disable_seq_and_redirect_scrub);
 
 #endif
+
+#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
+#include <linux/jump_label.h>
+#include <asm/string_64.h>
+
+/* Ivy Bridge, Haswell, Broadwell */
+static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
+{
+	u32 capid0;
+
+	pci_read_config_dword(pdev, 0x84, &capid0);
+
+	if (capid0 & 0x10)
+		static_branch_inc(&mcsafe_key);
+}
+
+/* Skylake */
+static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
+{
+	u32 capid0;
+
+	pci_read_config_dword(pdev, 0x84, &capid0);
+
+	if ((capid0 & 0xc0) == 0xc0)
+		static_branch_inc(&mcsafe_key);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_ras_cap);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
+#endif
-- 
2.5.0