[PATCH v1 0/5] x86/mce: Remove indirect calls

[PATCH v1 0/5] x86/mce: Remove indirect calls

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Hi,

here's v1 with all review comments addressed.

Changelog:
----------

v0:

this is the first part of me trying to noinstr-ify the mce mess
properly. That one is dealing with making all indirect calls on the #MC
exception path, direct, to avoid the compiler from adding ratpoline
thunks which objtool doesn't like. And when you look at the changes, you
probably would go, gee, why did we ever did indirect calls - it is even
more readable with direct calls and there are practically no downsides.
So let's remove former.

There's another patch ontop which does the actual noinstr annotation but
that takes longer currently due to objtool changes in tip.

So for now, the first part.

As always, constructive review is welcome.

Borislav Petkov (5):
  x86/mce: Get rid of the mce_severity function pointer
  x86/mce: Get rid of machine_check_vector
  x86/mce: Get rid of msr_ops
  x86/mce: Get rid of the ->quirk_no_way_out() indirect call
  x86/mce: Sort mca_config members to get rid of unnecessary padding

 arch/x86/include/asm/mce.h         |  12 --
 arch/x86/kernel/cpu/mce/amd.c      |  10 +-
 arch/x86/kernel/cpu/mce/core.c     | 217 ++++++++++++-----------------
 arch/x86/kernel/cpu/mce/internal.h |  59 +++++---
 arch/x86/kernel/cpu/mce/p5.c       |   6 +-
 arch/x86/kernel/cpu/mce/severity.c |  11 +-
 arch/x86/kernel/cpu/mce/winchip.c  |   6 +-
 7 files changed, 141 insertions(+), 180 deletions(-)

-- 
2.29.2

[PATCH v1 1/5] x86/mce: Get rid of the mce_severity function pointer

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Turn it into a normal function which calls an AMD- or Intel-specific
variant depending on the CPU it runs on.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/mce.h         |  2 --
 arch/x86/kernel/cpu/mce/core.c     |  1 -
 arch/x86/kernel/cpu/mce/internal.h |  3 +--
 arch/x86/kernel/cpu/mce/severity.c | 11 +++++------
 4 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index da9321548f6f..258ef6d9955c 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -205,14 +205,12 @@ struct cper_ia_proc_ctx;
 int mcheck_init(void);
 void mcheck_cpu_init(struct cpuinfo_x86 *c);
 void mcheck_cpu_clear(struct cpuinfo_x86 *c);
-void mcheck_vendor_init_severity(void);
 int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info,
 			       u64 lapic_id);
 #else
 static inline int mcheck_init(void) { return 0; }
 static inline void mcheck_cpu_init(struct cpuinfo_x86 *c) {}
 static inline void mcheck_cpu_clear(struct cpuinfo_x86 *c) {}
-static inline void mcheck_vendor_init_severity(void) {}
 static inline int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info,
 					     u64 lapic_id) { return -EINVAL; }
 #endif
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 69768fea1dac..aaede7ed9f77 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -2233,7 +2233,6 @@ int __init mcheck_init(void)
 	mce_register_decode_chain(&early_nb);
 	mce_register_decode_chain(&mce_uc_nb);
 	mce_register_decode_chain(&mce_default_nb);
-	mcheck_vendor_init_severity();
 
 	INIT_WORK(&mce_work, mce_gen_pool_process);
 	init_irq_work(&mce_irq_work, mce_irq_work_cb);
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 88dcc79cfb07..09cb5ab9a81d 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -38,8 +38,7 @@ int mce_gen_pool_add(struct mce *mce);
 int mce_gen_pool_init(void);
 struct llist_node *mce_gen_pool_prepare_records(void);
 
-extern int (*mce_severity)(struct mce *a, struct pt_regs *regs,
-			   int tolerant, char **msg, bool is_excp);
+int mce_severity(struct mce *a, struct pt_regs *regs, int tolerant, char **msg, bool is_excp);
 struct dentry *mce_get_debugfs_dir(void);
 
 extern mce_banks_t mce_banks_ce_disabled;
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index 17e631443116..695570fadb5e 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -407,15 +407,14 @@ static int mce_severity_intel(struct mce *m, struct pt_regs *regs,
 	}
 }
 
-/* Default to mce_severity_intel */
-int (*mce_severity)(struct mce *m, struct pt_regs *regs, int tolerant, char **msg, bool is_excp) =
-		    mce_severity_intel;
-
-void __init mcheck_vendor_init_severity(void)
+int mce_severity(struct mce *m, struct pt_regs *regs, int tolerant, char **msg,
+		 bool is_excp)
 {
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
 	    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
-		mce_severity = mce_severity_amd;
+		return mce_severity_amd(m, regs, tolerant, msg, is_excp);
+	else
+		return mce_severity_intel(m, regs, tolerant, msg, is_excp);
 }
 
 #ifdef CONFIG_DEBUG_FS
-- 
2.29.2

[PATCH v1 2/5] x86/mce: Get rid of machine_check_vector

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Get rid of the indirect function pointer and use flags settings instead
to steer execution.

Now that it is not an indirect call any longer, drop the instrumentation
annotation for objtool too.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/mce.h         | 10 ------
 arch/x86/kernel/cpu/mce/core.c     | 57 ++++++++++++++----------------
 arch/x86/kernel/cpu/mce/internal.h | 29 ++++++++++++---
 arch/x86/kernel/cpu/mce/p5.c       |  6 +---
 arch/x86/kernel/cpu/mce/winchip.c  |  6 +---
 5 files changed, 53 insertions(+), 55 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 258ef6d9955c..813b4f5b0dd6 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -215,16 +215,6 @@ static inline int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info,
 					     u64 lapic_id) { return -EINVAL; }
 #endif
 
-#ifdef CONFIG_X86_ANCIENT_MCE
-void intel_p5_mcheck_init(struct cpuinfo_x86 *c);
-void winchip_mcheck_init(struct cpuinfo_x86 *c);
-static inline void enable_p5_mce(void) { mce_p5_enabled = 1; }
-#else
-static inline void intel_p5_mcheck_init(struct cpuinfo_x86 *c) {}
-static inline void winchip_mcheck_init(struct cpuinfo_x86 *c) {}
-static inline void enable_p5_mce(void) {}
-#endif
-
 void mce_setup(struct mce *m);
 void mce_log(struct mce *m);
 DECLARE_PER_CPU(struct device *, mce_device);
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index aaede7ed9f77..7aff9a503d1c 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1328,6 +1328,15 @@ static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callba
 	task_work_add(current, &current->mce_kill_me, TWA_RESUME);
 }
 
+/* Handle unconfigured int18 (should never happen) */
+static noinstr void unexpected_machine_check(struct pt_regs *regs)
+{
+	instrumentation_begin();
+	pr_err("CPU#%d: Unexpected int18 (Machine Check)\n",
+	       smp_processor_id());
+	instrumentation_end();
+}
+
 /*
  * The actual machine check handler. This only handles real
  * exceptions when something got corrupted coming in through int 18.
@@ -1348,36 +1357,43 @@ static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callba
  */
 noinstr void do_machine_check(struct pt_regs *regs)
 {
+	int worst = 0, order, no_way_out, kill_current_task, lmce;
 	DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
 	DECLARE_BITMAP(toclear, MAX_NR_BANKS);
 	struct mca_config *cfg = &mca_cfg;
 	struct mce m, *final;
 	char *msg = NULL;
-	int worst = 0;
+
+	if (unlikely(mce_flags.p5))
+		return pentium_machine_check(regs);
+	else if (unlikely(mce_flags.winchip))
+		return winchip_machine_check(regs);
+	else if (unlikely(!mca_cfg.initialized))
+		return unexpected_machine_check(regs);
 
 	/*
 	 * Establish sequential order between the CPUs entering the machine
 	 * check handler.
 	 */
-	int order = -1;
+	order = -1;
 
 	/*
 	 * If no_way_out gets set, there is no safe way to recover from this
 	 * MCE.  If mca_cfg.tolerant is cranked up, we'll try anyway.
 	 */
-	int no_way_out = 0;
+	no_way_out = 0;
 
 	/*
 	 * If kill_current_task is not set, there might be a way to recover from this
 	 * error.
 	 */
-	int kill_current_task = 0;
+	kill_current_task = 0;
 
 	/*
 	 * MCEs are always local on AMD. Same is determined by MCG_STATUS_LMCES
 	 * on Intel.
 	 */
-	int lmce = 1;
+	lmce = 1;
 
 	this_cpu_inc(mce_exception_count);
 
@@ -1855,9 +1871,11 @@ static int __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
 	switch (c->x86_vendor) {
 	case X86_VENDOR_INTEL:
 		intel_p5_mcheck_init(c);
+		mce_flags.p5 = 1;
 		return 1;
 	case X86_VENDOR_CENTAUR:
 		winchip_mcheck_init(c);
+		mce_flags.winchip = 1;
 		return 1;
 	default:
 		return 0;
@@ -2012,18 +2030,6 @@ bool filter_mce(struct mce *m)
 	return false;
 }
 
-/* Handle unconfigured int18 (should never happen) */
-static noinstr void unexpected_machine_check(struct pt_regs *regs)
-{
-	instrumentation_begin();
-	pr_err("CPU#%d: Unexpected int18 (Machine Check)\n",
-	       smp_processor_id());
-	instrumentation_end();
-}
-
-/* Call the installed machine check handler for this CPU setup. */
-void (*machine_check_vector)(struct pt_regs *) = unexpected_machine_check;
-
 static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
 {
 	irqentry_state_t irq_state;
@@ -2034,31 +2040,22 @@ static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
 	 * Only required when from kernel mode. See
 	 * mce_check_crashing_cpu() for details.
 	 */
-	if (machine_check_vector == do_machine_check &&
-	    mce_check_crashing_cpu())
+	if (mca_cfg.initialized && mce_check_crashing_cpu())
 		return;
 
 	irq_state = irqentry_nmi_enter(regs);
-	/*
-	 * The call targets are marked noinstr, but objtool can't figure
-	 * that out because it's an indirect call. Annotate it.
-	 */
-	instrumentation_begin();
 
-	machine_check_vector(regs);
+	do_machine_check(regs);
 
-	instrumentation_end();
 	irqentry_nmi_exit(regs, irq_state);
 }
 
 static __always_inline void exc_machine_check_user(struct pt_regs *regs)
 {
 	irqentry_enter_from_user_mode(regs);
-	instrumentation_begin();
 
-	machine_check_vector(regs);
+	do_machine_check(regs);
 
-	instrumentation_end();
 	irqentry_exit_to_user_mode(regs);
 }
 
@@ -2125,7 +2122,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 		return;
 	}
 
-	machine_check_vector = do_machine_check;
+	mca_cfg.initialized = 1;
 
 	__mcheck_cpu_init_early(c);
 	__mcheck_cpu_init_generic();
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 09cb5ab9a81d..d71d6c5c3ef0 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -8,9 +8,6 @@
 #include <linux/device.h>
 #include <asm/mce.h>
 
-/* Pointer to the installed machine check handler for this CPU setup. */
-extern void (*machine_check_vector)(struct pt_regs *);
-
 enum severity_level {
 	MCE_NO_SEVERITY,
 	MCE_DEFERRED_SEVERITY,
@@ -126,7 +123,9 @@ struct mca_config {
 	      ser			: 1,
 	      recovery			: 1,
 	      bios_cmci_threshold	: 1,
-	      __reserved		: 59;
+	      /* Proper #MC exception handler is set */
+	      initialized		: 1,
+	      __reserved		: 58;
 
 	s8 bootlog;
 	int tolerant;
@@ -162,7 +161,13 @@ struct mce_vendor_flags {
 	/* AMD-style error thresholding banks present. */
 	amd_threshold		: 1,
 
-	__reserved_0		: 60;
+	/* Pentium, family 5-style MCA */
+	p5			: 1,
+
+	/* Centaur Winchip C6-style MCA */
+	winchip			: 1,
+
+	__reserved_0		: 58;
 };
 
 extern struct mce_vendor_flags mce_flags;
@@ -195,4 +200,18 @@ __visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup,
 				      unsigned long error_code,
 				      unsigned long fault_addr);
 
+#ifdef CONFIG_X86_ANCIENT_MCE
+void intel_p5_mcheck_init(struct cpuinfo_x86 *c);
+void winchip_mcheck_init(struct cpuinfo_x86 *c);
+noinstr void pentium_machine_check(struct pt_regs *regs);
+noinstr void winchip_machine_check(struct pt_regs *regs);
+static inline void enable_p5_mce(void) { mce_p5_enabled = 1; }
+#else
+static inline void intel_p5_mcheck_init(struct cpuinfo_x86 *c) {}
+static inline void winchip_mcheck_init(struct cpuinfo_x86 *c) {}
+static inline void enable_p5_mce(void) {}
+static inline void pentium_machine_check(struct pt_regs *regs) {}
+static inline void winchip_machine_check(struct pt_regs *regs) {}
+#endif
+
 #endif /* __X86_MCE_INTERNAL_H__ */
diff --git a/arch/x86/kernel/cpu/mce/p5.c b/arch/x86/kernel/cpu/mce/p5.c
index 19e90cae8e97..2272ad53fc33 100644
--- a/arch/x86/kernel/cpu/mce/p5.c
+++ b/arch/x86/kernel/cpu/mce/p5.c
@@ -21,7 +21,7 @@
 int mce_p5_enabled __read_mostly;
 
 /* Machine check handler for Pentium class Intel CPUs: */
-static noinstr void pentium_machine_check(struct pt_regs *regs)
+noinstr void pentium_machine_check(struct pt_regs *regs)
 {
 	u32 loaddr, hi, lotype;
 
@@ -54,10 +54,6 @@ void intel_p5_mcheck_init(struct cpuinfo_x86 *c)
 	if (!cpu_has(c, X86_FEATURE_MCE))
 		return;
 
-	machine_check_vector = pentium_machine_check;
-	/* Make sure the vector pointer is visible before we enable MCEs: */
-	wmb();
-
 	/* Read registers before enabling: */
 	rdmsr(MSR_IA32_P5_MC_ADDR, l, h);
 	rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
diff --git a/arch/x86/kernel/cpu/mce/winchip.c b/arch/x86/kernel/cpu/mce/winchip.c
index 9c9f0abd2d7f..6c99f2941909 100644
--- a/arch/x86/kernel/cpu/mce/winchip.c
+++ b/arch/x86/kernel/cpu/mce/winchip.c
@@ -17,7 +17,7 @@
 #include "internal.h"
 
 /* Machine check handler for WinChip C6: */
-static noinstr void winchip_machine_check(struct pt_regs *regs)
+noinstr void winchip_machine_check(struct pt_regs *regs)
 {
 	instrumentation_begin();
 	pr_emerg("CPU0: Machine Check Exception.\n");
@@ -30,10 +30,6 @@ void winchip_mcheck_init(struct cpuinfo_x86 *c)
 {
 	u32 lo, hi;
 
-	machine_check_vector = winchip_machine_check;
-	/* Make sure the vector pointer is visible before we enable MCEs: */
-	wmb();
-
 	rdmsr(MSR_IDT_FCR1, lo, hi);
 	lo |= (1<<2);	/* Enable EIERRINT (int 18 MCE) */
 	lo &= ~(1<<4);	/* Enable MCE */
-- 
2.29.2

[PATCH v1 3/5] x86/mce: Get rid of msr_ops

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Avoid having indirect calls and use a normal function which returns the
proper MSR address based on ->smca setting.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/cpu/mce/amd.c      | 10 ++--
 arch/x86/kernel/cpu/mce/core.c     | 95 ++++++++++--------------------
 arch/x86/kernel/cpu/mce/internal.h | 12 ++--
 3 files changed, 42 insertions(+), 75 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 08831acc1d03..27cacf504663 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -526,7 +526,7 @@ static u32 get_block_address(u32 current_addr, u32 low, u32 high,
 	/* Fall back to method we used for older processors: */
 	switch (block) {
 	case 0:
-		addr = msr_ops.misc(bank);
+		addr = mca_msr_reg(bank, MCA_MISC);
 		break;
 	case 1:
 		offset = ((low & MASK_BLKPTR_LO) >> 21);
@@ -978,8 +978,8 @@ static void log_error_deferred(unsigned int bank)
 {
 	bool defrd;
 
-	defrd = _log_error_bank(bank, msr_ops.status(bank),
-					msr_ops.addr(bank), 0);
+	defrd = _log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS),
+				mca_msr_reg(bank, MCA_ADDR), 0);
 
 	if (!mce_flags.smca)
 		return;
@@ -1009,7 +1009,7 @@ static void amd_deferred_error_interrupt(void)
 
 static void log_error_thresholding(unsigned int bank, u64 misc)
 {
-	_log_error_bank(bank, msr_ops.status(bank), msr_ops.addr(bank), misc);
+	_log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), mca_msr_reg(bank, MCA_ADDR), misc);
 }
 
 static void log_and_reset_block(struct threshold_block *block)
@@ -1397,7 +1397,7 @@ static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
 		}
 	}
 
-	err = allocate_threshold_blocks(cpu, b, bank, 0, msr_ops.misc(bank));
+	err = allocate_threshold_blocks(cpu, b, bank, 0, mca_msr_reg(bank, MCA_MISC));
 	if (err)
 		goto out_kobj;
 
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 7aff9a503d1c..8e766b2685d6 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -176,53 +176,27 @@ void mce_unregister_decode_chain(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
 
-static inline u32 ctl_reg(int bank)
+u32 mca_msr_reg(int bank, enum mca_msr reg)
 {
-	return MSR_IA32_MCx_CTL(bank);
-}
-
-static inline u32 status_reg(int bank)
-{
-	return MSR_IA32_MCx_STATUS(bank);
-}
-
-static inline u32 addr_reg(int bank)
-{
-	return MSR_IA32_MCx_ADDR(bank);
-}
-
-static inline u32 misc_reg(int bank)
-{
-	return MSR_IA32_MCx_MISC(bank);
-}
-
-static inline u32 smca_ctl_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_CTL(bank);
-}
-
-static inline u32 smca_status_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_STATUS(bank);
-}
+	if (mce_flags.smca) {
+		switch (reg) {
+		case MCA_CTL:	 return MSR_AMD64_SMCA_MCx_CTL(bank);
+		case MCA_ADDR:	 return MSR_AMD64_SMCA_MCx_ADDR(bank);
+		case MCA_MISC:	 return MSR_AMD64_SMCA_MCx_MISC(bank);
+		case MCA_STATUS: return MSR_AMD64_SMCA_MCx_STATUS(bank);
+		}
+	}
 
-static inline u32 smca_addr_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_ADDR(bank);
-}
+	switch (reg) {
+	case MCA_CTL:	 return MSR_IA32_MCx_CTL(bank);
+	case MCA_ADDR:	 return MSR_IA32_MCx_ADDR(bank);
+	case MCA_MISC:	 return MSR_IA32_MCx_MISC(bank);
+	case MCA_STATUS: return MSR_IA32_MCx_STATUS(bank);
+	}
 
-static inline u32 smca_misc_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_MISC(bank);
+	return 0;
 }
 
-struct mca_msr_regs msr_ops = {
-	.ctl	= ctl_reg,
-	.status	= status_reg,
-	.addr	= addr_reg,
-	.misc	= misc_reg
-};
-
 static void __print_mce(struct mce *m)
 {
 	pr_emerg(HW_ERR "CPU %d: Machine Check%s: %Lx Bank %d: %016Lx\n",
@@ -362,11 +336,11 @@ static int msr_to_offset(u32 msr)
 
 	if (msr == mca_cfg.rip_msr)
 		return offsetof(struct mce, ip);
-	if (msr == msr_ops.status(bank))
+	if (msr == mca_msr_reg(bank, MCA_STATUS))
 		return offsetof(struct mce, status);
-	if (msr == msr_ops.addr(bank))
+	if (msr == mca_msr_reg(bank, MCA_ADDR))
 		return offsetof(struct mce, addr);
-	if (msr == msr_ops.misc(bank))
+	if (msr == mca_msr_reg(bank, MCA_MISC))
 		return offsetof(struct mce, misc);
 	if (msr == MSR_IA32_MCG_STATUS)
 		return offsetof(struct mce, mcgstatus);
@@ -685,10 +659,10 @@ static struct notifier_block mce_default_nb = {
 static void mce_read_aux(struct mce *m, int i)
 {
 	if (m->status & MCI_STATUS_MISCV)
-		m->misc = mce_rdmsrl(msr_ops.misc(i));
+		m->misc = mce_rdmsrl(mca_msr_reg(i, MCA_MISC));
 
 	if (m->status & MCI_STATUS_ADDRV) {
-		m->addr = mce_rdmsrl(msr_ops.addr(i));
+		m->addr = mce_rdmsrl(mca_msr_reg(i, MCA_ADDR));
 
 		/*
 		 * Mask the reported address by the reported granularity.
@@ -758,7 +732,7 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
 		m.bank = i;
 
 		barrier();
-		m.status = mce_rdmsrl(msr_ops.status(i));
+		m.status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
 
 		/* If this entry is not valid, ignore it */
 		if (!(m.status & MCI_STATUS_VAL))
@@ -826,7 +800,7 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
 		/*
 		 * Clear state for this bank.
 		 */
-		mce_wrmsrl(msr_ops.status(i), 0);
+		mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
 	}
 
 	/*
@@ -851,7 +825,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
 	int i;
 
 	for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
-		m->status = mce_rdmsrl(msr_ops.status(i));
+		m->status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
 		if (!(m->status & MCI_STATUS_VAL))
 			continue;
 
@@ -1144,7 +1118,7 @@ static void mce_clear_state(unsigned long *toclear)
 
 	for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
 		if (test_bit(i, toclear))
-			mce_wrmsrl(msr_ops.status(i), 0);
+			mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
 	}
 }
 
@@ -1203,7 +1177,7 @@ static void __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *fin
 		m->addr = 0;
 		m->bank = i;
 
-		m->status = mce_rdmsrl(msr_ops.status(i));
+		m->status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
 		if (!(m->status & MCI_STATUS_VAL))
 			continue;
 
@@ -1708,8 +1682,8 @@ static void __mcheck_cpu_init_clear_banks(void)
 
 		if (!b->init)
 			continue;
-		wrmsrl(msr_ops.ctl(i), b->ctl);
-		wrmsrl(msr_ops.status(i), 0);
+		wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl);
+		wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
 	}
 }
 
@@ -1735,7 +1709,7 @@ static void __mcheck_cpu_check_banks(void)
 		if (!b->init)
 			continue;
 
-		rdmsrl(msr_ops.ctl(i), msrval);
+		rdmsrl(mca_msr_reg(i, MCA_CTL), msrval);
 		b->init = !!msrval;
 	}
 }
@@ -1894,13 +1868,6 @@ static void __mcheck_cpu_init_early(struct cpuinfo_x86 *c)
 		mce_flags.succor	 = !!cpu_has(c, X86_FEATURE_SUCCOR);
 		mce_flags.smca		 = !!cpu_has(c, X86_FEATURE_SMCA);
 		mce_flags.amd_threshold	 = 1;
-
-		if (mce_flags.smca) {
-			msr_ops.ctl	= smca_ctl_reg;
-			msr_ops.status	= smca_status_reg;
-			msr_ops.addr	= smca_addr_reg;
-			msr_ops.misc	= smca_misc_reg;
-		}
 	}
 }
 
@@ -2254,7 +2221,7 @@ static void mce_disable_error_reporting(void)
 		struct mce_bank *b = &mce_banks[i];
 
 		if (b->init)
-			wrmsrl(msr_ops.ctl(i), 0);
+			wrmsrl(mca_msr_reg(i, MCA_CTL), 0);
 	}
 	return;
 }
@@ -2606,7 +2573,7 @@ static void mce_reenable_cpu(void)
 		struct mce_bank *b = &mce_banks[i];
 
 		if (b->init)
-			wrmsrl(msr_ops.ctl(i), b->ctl);
+			wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl);
 	}
 }
 
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index d71d6c5c3ef0..1ad7b4bf5423 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -172,14 +172,14 @@ struct mce_vendor_flags {
 
 extern struct mce_vendor_flags mce_flags;
 
-struct mca_msr_regs {
-	u32 (*ctl)	(int bank);
-	u32 (*status)	(int bank);
-	u32 (*addr)	(int bank);
-	u32 (*misc)	(int bank);
+enum mca_msr {
+	MCA_CTL,
+	MCA_STATUS,
+	MCA_ADDR,
+	MCA_MISC,
 };
 
-extern struct mca_msr_regs msr_ops;
+u32 mca_msr_reg(int bank, enum mca_msr reg);
 
 /* Decide whether to add MCE record to MCE event pool or filter it out. */
 extern bool filter_mce(struct mce *m);
-- 
2.29.2

[PATCH v1 4/5] x86/mce: Get rid of the ->quirk_no_way_out() indirect call

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Use a flag setting to call the only quirk function for that.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/cpu/mce/core.c     | 64 +++++++++++++++---------------
 arch/x86/kernel/cpu/mce/internal.h |  5 ++-
 2 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 8e766b2685d6..50a3e455cded 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -121,8 +121,6 @@ mce_banks_t mce_banks_ce_disabled;
 static struct work_struct mce_work;
 static struct irq_work mce_irq_work;
 
-static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs);
-
 /*
  * CPU/chipset specific EDAC code can register a notifier call here to print
  * MCE errors in a human-readable form.
@@ -814,6 +812,34 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
 }
 EXPORT_SYMBOL_GPL(machine_check_poll);
 
+/*
+ * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and
+ * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM
+ * Vol 3B Table 15-20). But this confuses both the code that determines
+ * whether the machine check occurred in kernel or user mode, and also
+ * the severity assessment code. Pretend that EIPV was set, and take the
+ * ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
+ */
+static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
+{
+	if (bank != 0)
+		return;
+	if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0)
+		return;
+	if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC|
+		          MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV|
+			  MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR|
+			  MCACOD)) !=
+			 (MCI_STATUS_UC|MCI_STATUS_EN|
+			  MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S|
+			  MCI_STATUS_AR|MCACOD_INSTR))
+		return;
+
+	m->mcgstatus |= MCG_STATUS_EIPV;
+	m->ip = regs->ip;
+	m->cs = regs->cs;
+}
+
 /*
  * Do a quick check if any of the events requires a panic.
  * This decides if we keep the events around or clear them.
@@ -830,8 +856,8 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
 			continue;
 
 		__set_bit(i, validp);
-		if (quirk_no_way_out)
-			quirk_no_way_out(i, m, regs);
+		if (mce_flags.snb_ifu_quirk)
+			quirk_sandybridge_ifu(i, m, regs);
 
 		m->bank = i;
 		if (mce_severity(m, regs, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
@@ -1714,34 +1740,6 @@ static void __mcheck_cpu_check_banks(void)
 	}
 }
 
-/*
- * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and
- * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM
- * Vol 3B Table 15-20). But this confuses both the code that determines
- * whether the machine check occurred in kernel or user mode, and also
- * the severity assessment code. Pretend that EIPV was set, and take the
- * ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
- */
-static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
-{
-	if (bank != 0)
-		return;
-	if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0)
-		return;
-	if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC|
-		          MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV|
-			  MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR|
-			  MCACOD)) !=
-			 (MCI_STATUS_UC|MCI_STATUS_EN|
-			  MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S|
-			  MCI_STATUS_AR|MCACOD_INSTR))
-		return;
-
-	m->mcgstatus |= MCG_STATUS_EIPV;
-	m->ip = regs->ip;
-	m->cs = regs->cs;
-}
-
 /* Add per CPU specific workarounds here */
 static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 {
@@ -1815,7 +1813,7 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 			cfg->bootlog = 0;
 
 		if (c->x86 == 6 && c->x86_model == 45)
-			quirk_no_way_out = quirk_sandybridge_ifu;
+			mce_flags.snb_ifu_quirk = 1;
 	}
 
 	if (c->x86_vendor == X86_VENDOR_ZHAOXIN) {
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 1ad7b4bf5423..21865545cd3b 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -167,7 +167,10 @@ struct mce_vendor_flags {
 	/* Centaur Winchip C6-style MCA */
 	winchip			: 1,
 
-	__reserved_0		: 58;
+	/* SandyBridge IFU quirk */
+	snb_ifu_quirk		: 1,
+
+	__reserved_0		: 57;
 };
 
 extern struct mce_vendor_flags mce_flags;
-- 
2.29.2

[PATCH v1 5/5] x86/mce: Sort mca_config members to get rid of unnecessary padding

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

$ pahole -C mca_config arch/x86/kernel/cpu/mce/core.o

before:

   /* size: 40, cachelines: 1, members: 16 */
   /* sum members: 21, holes: 1, sum holes: 3 */
   /* sum bitfield members: 64 bits, bit holes: 2, sum bit holes: 32 bits */
   /* padding: 4 */
   /* last cacheline: 40 bytes */

after:

   /* size: 32, cachelines: 1, members: 16 */
   /* padding: 3 */
   /* last cacheline: 32 bytes */

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/cpu/mce/internal.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 21865545cd3b..37b9e381ef02 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -113,11 +113,6 @@ static inline void mce_unregister_injector_chain(struct notifier_block *nb)	{ }
 #endif
 
 struct mca_config {
-	bool dont_log_ce;
-	bool cmci_disabled;
-	bool ignore_ce;
-	bool print_all;
-
 	__u64 lmce_disabled		: 1,
 	      disabled			: 1,
 	      ser			: 1,
@@ -127,11 +122,16 @@ struct mca_config {
 	      initialized		: 1,
 	      __reserved		: 58;
 
-	s8 bootlog;
+	bool dont_log_ce;
+	bool cmci_disabled;
+	bool ignore_ce;
+	bool print_all;
+
 	int tolerant;
 	int monarch_timeout;
 	int panic_timeout;
 	u32 rip_msr;
+	s8 bootlog;
 };
 
 extern struct mca_config mca_cfg;
-- 
2.29.2

Re: [PATCH v1 0/5] x86/mce: Remove indirect calls

[Luck, Tony]

On Wed, Sep 22, 2021 at 06:50:56PM +0200, Borislav Petkov wrote:
> From: Borislav Petkov <bp@suse.de>
> 
> Hi,
> 
> here's v1 with all review comments addressed.

Looks good to me.

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

Some light testing of injection/recovery still
works too.

-Tony

Re: [PATCH v1 0/5] x86/mce: Remove indirect calls

[Borislav Petkov]

On Wed, Sep 22, 2021 at 01:35:09PM -0700, Luck, Tony wrote:
> Looks good to me.
> 
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> 
> Some light testing of injection/recovery still
> works too.

Thanks!

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

[tip: ras/core] x86/mce: Sort mca_config members to get rid of unnecessary padding

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the ras/core branch of tip:

Commit-ID:     15802468a95bd8ec9060eb861468f4a0f0106fa4
Gitweb:        https://git.kernel.org/tip/15802468a95bd8ec9060eb861468f4a0f0106fa4
Author:        Borislav Petkov <bp@suse.de>
AuthorDate:    Wed, 22 Sep 2021 18:44:17 +02:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 23 Sep 2021 11:38:04 +02:00

x86/mce: Sort mca_config members to get rid of unnecessary padding

$ pahole -C mca_config arch/x86/kernel/cpu/mce/core.o

before:

   /* size: 40, cachelines: 1, members: 16 */
   /* sum members: 21, holes: 1, sum holes: 3 */
   /* sum bitfield members: 64 bits, bit holes: 2, sum bit holes: 32 bits */
   /* padding: 4 */
   /* last cacheline: 40 bytes */

after:

   /* size: 32, cachelines: 1, members: 16 */
   /* padding: 3 */
   /* last cacheline: 32 bytes */

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20210922165101.18951-6-bp@alien8.de
---
 arch/x86/kernel/cpu/mce/internal.h | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 2186554..37b9e38 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -113,11 +113,6 @@ static inline void mce_unregister_injector_chain(struct notifier_block *nb)	{ }
 #endif
 
 struct mca_config {
-	bool dont_log_ce;
-	bool cmci_disabled;
-	bool ignore_ce;
-	bool print_all;
-
 	__u64 lmce_disabled		: 1,
 	      disabled			: 1,
 	      ser			: 1,
@@ -127,11 +122,16 @@ struct mca_config {
 	      initialized		: 1,
 	      __reserved		: 58;
 
-	s8 bootlog;
+	bool dont_log_ce;
+	bool cmci_disabled;
+	bool ignore_ce;
+	bool print_all;
+
 	int tolerant;
 	int monarch_timeout;
 	int panic_timeout;
 	u32 rip_msr;
+	s8 bootlog;
 };
 
 extern struct mca_config mca_cfg;

[tip: ras/core] x86/mce: Get rid of the ->quirk_no_way_out() indirect call

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the ras/core branch of tip:

Commit-ID:     cc466666ab0920acfa879326ed9f7ef555323261
Gitweb:        https://git.kernel.org/tip/cc466666ab0920acfa879326ed9f7ef555323261
Author:        Borislav Petkov <bp@suse.de>
AuthorDate:    Thu, 02 Sep 2021 20:23:00 +02:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 23 Sep 2021 11:34:49 +02:00

x86/mce: Get rid of the ->quirk_no_way_out() indirect call

Use a flag setting to call the only quirk function for that.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20210922165101.18951-5-bp@alien8.de
---
 arch/x86/kernel/cpu/mce/core.c     | 64 ++++++++++++++---------------
 arch/x86/kernel/cpu/mce/internal.h |  5 +-
 2 files changed, 35 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 8e766b2..50a3e45 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -121,8 +121,6 @@ mce_banks_t mce_banks_ce_disabled;
 static struct work_struct mce_work;
 static struct irq_work mce_irq_work;
 
-static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs);
-
 /*
  * CPU/chipset specific EDAC code can register a notifier call here to print
  * MCE errors in a human-readable form.
@@ -815,6 +813,34 @@ clear_it:
 EXPORT_SYMBOL_GPL(machine_check_poll);
 
 /*
+ * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and
+ * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM
+ * Vol 3B Table 15-20). But this confuses both the code that determines
+ * whether the machine check occurred in kernel or user mode, and also
+ * the severity assessment code. Pretend that EIPV was set, and take the
+ * ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
+ */
+static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
+{
+	if (bank != 0)
+		return;
+	if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0)
+		return;
+	if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC|
+		          MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV|
+			  MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR|
+			  MCACOD)) !=
+			 (MCI_STATUS_UC|MCI_STATUS_EN|
+			  MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S|
+			  MCI_STATUS_AR|MCACOD_INSTR))
+		return;
+
+	m->mcgstatus |= MCG_STATUS_EIPV;
+	m->ip = regs->ip;
+	m->cs = regs->cs;
+}
+
+/*
  * Do a quick check if any of the events requires a panic.
  * This decides if we keep the events around or clear them.
  */
@@ -830,8 +856,8 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
 			continue;
 
 		__set_bit(i, validp);
-		if (quirk_no_way_out)
-			quirk_no_way_out(i, m, regs);
+		if (mce_flags.snb_ifu_quirk)
+			quirk_sandybridge_ifu(i, m, regs);
 
 		m->bank = i;
 		if (mce_severity(m, regs, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
@@ -1714,34 +1740,6 @@ static void __mcheck_cpu_check_banks(void)
 	}
 }
 
-/*
- * During IFU recovery Sandy Bridge -EP4S processors set the RIPV and
- * EIPV bits in MCG_STATUS to zero on the affected logical processor (SDM
- * Vol 3B Table 15-20). But this confuses both the code that determines
- * whether the machine check occurred in kernel or user mode, and also
- * the severity assessment code. Pretend that EIPV was set, and take the
- * ip/cs values from the pt_regs that mce_gather_info() ignored earlier.
- */
-static void quirk_sandybridge_ifu(int bank, struct mce *m, struct pt_regs *regs)
-{
-	if (bank != 0)
-		return;
-	if ((m->mcgstatus & (MCG_STATUS_EIPV|MCG_STATUS_RIPV)) != 0)
-		return;
-	if ((m->status & (MCI_STATUS_OVER|MCI_STATUS_UC|
-		          MCI_STATUS_EN|MCI_STATUS_MISCV|MCI_STATUS_ADDRV|
-			  MCI_STATUS_PCC|MCI_STATUS_S|MCI_STATUS_AR|
-			  MCACOD)) !=
-			 (MCI_STATUS_UC|MCI_STATUS_EN|
-			  MCI_STATUS_MISCV|MCI_STATUS_ADDRV|MCI_STATUS_S|
-			  MCI_STATUS_AR|MCACOD_INSTR))
-		return;
-
-	m->mcgstatus |= MCG_STATUS_EIPV;
-	m->ip = regs->ip;
-	m->cs = regs->cs;
-}
-
 /* Add per CPU specific workarounds here */
 static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 {
@@ -1815,7 +1813,7 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c)
 			cfg->bootlog = 0;
 
 		if (c->x86 == 6 && c->x86_model == 45)
-			quirk_no_way_out = quirk_sandybridge_ifu;
+			mce_flags.snb_ifu_quirk = 1;
 	}
 
 	if (c->x86_vendor == X86_VENDOR_ZHAOXIN) {
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 1ad7b4b..2186554 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -167,7 +167,10 @@ struct mce_vendor_flags {
 	/* Centaur Winchip C6-style MCA */
 	winchip			: 1,
 
-	__reserved_0		: 58;
+	/* SandyBridge IFU quirk */
+	snb_ifu_quirk		: 1,
+
+	__reserved_0		: 57;
 };
 
 extern struct mce_vendor_flags mce_flags;

[tip: ras/core] x86/mce: Get rid of msr_ops

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the ras/core branch of tip:

Commit-ID:     8121b8f947be0033f567619be204639a50cad298
Gitweb:        https://git.kernel.org/tip/8121b8f947be0033f567619be204639a50cad298
Author:        Borislav Petkov <bp@suse.de>
AuthorDate:    Thu, 02 Sep 2021 13:33:22 +02:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 23 Sep 2021 11:20:20 +02:00

x86/mce: Get rid of msr_ops

Avoid having indirect calls and use a normal function which returns the
proper MSR address based on ->smca setting.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20210922165101.18951-4-bp@alien8.de
---
 arch/x86/kernel/cpu/mce/amd.c      | 10 +--
 arch/x86/kernel/cpu/mce/core.c     | 95 +++++++++--------------------
 arch/x86/kernel/cpu/mce/internal.h | 12 ++--
 3 files changed, 42 insertions(+), 75 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/amd.c b/arch/x86/kernel/cpu/mce/amd.c
index 08831ac..27cacf5 100644
--- a/arch/x86/kernel/cpu/mce/amd.c
+++ b/arch/x86/kernel/cpu/mce/amd.c
@@ -526,7 +526,7 @@ static u32 get_block_address(u32 current_addr, u32 low, u32 high,
 	/* Fall back to method we used for older processors: */
 	switch (block) {
 	case 0:
-		addr = msr_ops.misc(bank);
+		addr = mca_msr_reg(bank, MCA_MISC);
 		break;
 	case 1:
 		offset = ((low & MASK_BLKPTR_LO) >> 21);
@@ -978,8 +978,8 @@ static void log_error_deferred(unsigned int bank)
 {
 	bool defrd;
 
-	defrd = _log_error_bank(bank, msr_ops.status(bank),
-					msr_ops.addr(bank), 0);
+	defrd = _log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS),
+				mca_msr_reg(bank, MCA_ADDR), 0);
 
 	if (!mce_flags.smca)
 		return;
@@ -1009,7 +1009,7 @@ static void amd_deferred_error_interrupt(void)
 
 static void log_error_thresholding(unsigned int bank, u64 misc)
 {
-	_log_error_bank(bank, msr_ops.status(bank), msr_ops.addr(bank), misc);
+	_log_error_bank(bank, mca_msr_reg(bank, MCA_STATUS), mca_msr_reg(bank, MCA_ADDR), misc);
 }
 
 static void log_and_reset_block(struct threshold_block *block)
@@ -1397,7 +1397,7 @@ static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
 		}
 	}
 
-	err = allocate_threshold_blocks(cpu, b, bank, 0, msr_ops.misc(bank));
+	err = allocate_threshold_blocks(cpu, b, bank, 0, mca_msr_reg(bank, MCA_MISC));
 	if (err)
 		goto out_kobj;
 
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 7aff9a5..8e766b2 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -176,53 +176,27 @@ void mce_unregister_decode_chain(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
 
-static inline u32 ctl_reg(int bank)
+u32 mca_msr_reg(int bank, enum mca_msr reg)
 {
-	return MSR_IA32_MCx_CTL(bank);
-}
-
-static inline u32 status_reg(int bank)
-{
-	return MSR_IA32_MCx_STATUS(bank);
-}
-
-static inline u32 addr_reg(int bank)
-{
-	return MSR_IA32_MCx_ADDR(bank);
-}
-
-static inline u32 misc_reg(int bank)
-{
-	return MSR_IA32_MCx_MISC(bank);
-}
-
-static inline u32 smca_ctl_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_CTL(bank);
-}
-
-static inline u32 smca_status_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_STATUS(bank);
-}
+	if (mce_flags.smca) {
+		switch (reg) {
+		case MCA_CTL:	 return MSR_AMD64_SMCA_MCx_CTL(bank);
+		case MCA_ADDR:	 return MSR_AMD64_SMCA_MCx_ADDR(bank);
+		case MCA_MISC:	 return MSR_AMD64_SMCA_MCx_MISC(bank);
+		case MCA_STATUS: return MSR_AMD64_SMCA_MCx_STATUS(bank);
+		}
+	}
 
-static inline u32 smca_addr_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_ADDR(bank);
-}
+	switch (reg) {
+	case MCA_CTL:	 return MSR_IA32_MCx_CTL(bank);
+	case MCA_ADDR:	 return MSR_IA32_MCx_ADDR(bank);
+	case MCA_MISC:	 return MSR_IA32_MCx_MISC(bank);
+	case MCA_STATUS: return MSR_IA32_MCx_STATUS(bank);
+	}
 
-static inline u32 smca_misc_reg(int bank)
-{
-	return MSR_AMD64_SMCA_MCx_MISC(bank);
+	return 0;
 }
 
-struct mca_msr_regs msr_ops = {
-	.ctl	= ctl_reg,
-	.status	= status_reg,
-	.addr	= addr_reg,
-	.misc	= misc_reg
-};
-
 static void __print_mce(struct mce *m)
 {
 	pr_emerg(HW_ERR "CPU %d: Machine Check%s: %Lx Bank %d: %016Lx\n",
@@ -362,11 +336,11 @@ static int msr_to_offset(u32 msr)
 
 	if (msr == mca_cfg.rip_msr)
 		return offsetof(struct mce, ip);
-	if (msr == msr_ops.status(bank))
+	if (msr == mca_msr_reg(bank, MCA_STATUS))
 		return offsetof(struct mce, status);
-	if (msr == msr_ops.addr(bank))
+	if (msr == mca_msr_reg(bank, MCA_ADDR))
 		return offsetof(struct mce, addr);
-	if (msr == msr_ops.misc(bank))
+	if (msr == mca_msr_reg(bank, MCA_MISC))
 		return offsetof(struct mce, misc);
 	if (msr == MSR_IA32_MCG_STATUS)
 		return offsetof(struct mce, mcgstatus);
@@ -685,10 +659,10 @@ static struct notifier_block mce_default_nb = {
 static void mce_read_aux(struct mce *m, int i)
 {
 	if (m->status & MCI_STATUS_MISCV)
-		m->misc = mce_rdmsrl(msr_ops.misc(i));
+		m->misc = mce_rdmsrl(mca_msr_reg(i, MCA_MISC));
 
 	if (m->status & MCI_STATUS_ADDRV) {
-		m->addr = mce_rdmsrl(msr_ops.addr(i));
+		m->addr = mce_rdmsrl(mca_msr_reg(i, MCA_ADDR));
 
 		/*
 		 * Mask the reported address by the reported granularity.
@@ -758,7 +732,7 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
 		m.bank = i;
 
 		barrier();
-		m.status = mce_rdmsrl(msr_ops.status(i));
+		m.status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
 
 		/* If this entry is not valid, ignore it */
 		if (!(m.status & MCI_STATUS_VAL))
@@ -826,7 +800,7 @@ clear_it:
 		/*
 		 * Clear state for this bank.
 		 */
-		mce_wrmsrl(msr_ops.status(i), 0);
+		mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
 	}
 
 	/*
@@ -851,7 +825,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
 	int i;
 
 	for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
-		m->status = mce_rdmsrl(msr_ops.status(i));
+		m->status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
 		if (!(m->status & MCI_STATUS_VAL))
 			continue;
 
@@ -1144,7 +1118,7 @@ static void mce_clear_state(unsigned long *toclear)
 
 	for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
 		if (test_bit(i, toclear))
-			mce_wrmsrl(msr_ops.status(i), 0);
+			mce_wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
 	}
 }
 
@@ -1203,7 +1177,7 @@ static void __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *fin
 		m->addr = 0;
 		m->bank = i;
 
-		m->status = mce_rdmsrl(msr_ops.status(i));
+		m->status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
 		if (!(m->status & MCI_STATUS_VAL))
 			continue;
 
@@ -1708,8 +1682,8 @@ static void __mcheck_cpu_init_clear_banks(void)
 
 		if (!b->init)
 			continue;
-		wrmsrl(msr_ops.ctl(i), b->ctl);
-		wrmsrl(msr_ops.status(i), 0);
+		wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl);
+		wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
 	}
 }
 
@@ -1735,7 +1709,7 @@ static void __mcheck_cpu_check_banks(void)
 		if (!b->init)
 			continue;
 
-		rdmsrl(msr_ops.ctl(i), msrval);
+		rdmsrl(mca_msr_reg(i, MCA_CTL), msrval);
 		b->init = !!msrval;
 	}
 }
@@ -1894,13 +1868,6 @@ static void __mcheck_cpu_init_early(struct cpuinfo_x86 *c)
 		mce_flags.succor	 = !!cpu_has(c, X86_FEATURE_SUCCOR);
 		mce_flags.smca		 = !!cpu_has(c, X86_FEATURE_SMCA);
 		mce_flags.amd_threshold	 = 1;
-
-		if (mce_flags.smca) {
-			msr_ops.ctl	= smca_ctl_reg;
-			msr_ops.status	= smca_status_reg;
-			msr_ops.addr	= smca_addr_reg;
-			msr_ops.misc	= smca_misc_reg;
-		}
 	}
 }
 
@@ -2254,7 +2221,7 @@ static void mce_disable_error_reporting(void)
 		struct mce_bank *b = &mce_banks[i];
 
 		if (b->init)
-			wrmsrl(msr_ops.ctl(i), 0);
+			wrmsrl(mca_msr_reg(i, MCA_CTL), 0);
 	}
 	return;
 }
@@ -2606,7 +2573,7 @@ static void mce_reenable_cpu(void)
 		struct mce_bank *b = &mce_banks[i];
 
 		if (b->init)
-			wrmsrl(msr_ops.ctl(i), b->ctl);
+			wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl);
 	}
 }
 
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index d71d6c5..1ad7b4b 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -172,14 +172,14 @@ struct mce_vendor_flags {
 
 extern struct mce_vendor_flags mce_flags;
 
-struct mca_msr_regs {
-	u32 (*ctl)	(int bank);
-	u32 (*status)	(int bank);
-	u32 (*addr)	(int bank);
-	u32 (*misc)	(int bank);
+enum mca_msr {
+	MCA_CTL,
+	MCA_STATUS,
+	MCA_ADDR,
+	MCA_MISC,
 };
 
-extern struct mca_msr_regs msr_ops;
+u32 mca_msr_reg(int bank, enum mca_msr reg);
 
 /* Decide whether to add MCE record to MCE event pool or filter it out. */
 extern bool filter_mce(struct mce *m);

[tip: ras/core] x86/mce: Get rid of machine_check_vector

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the ras/core branch of tip:

Commit-ID:     cbe1de162d8297e941f01ac7dd399a11251352bc
Gitweb:        https://git.kernel.org/tip/cbe1de162d8297e941f01ac7dd399a11251352bc
Author:        Borislav Petkov <bp@suse.de>
AuthorDate:    Wed, 01 Sep 2021 21:40:14 +02:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 23 Sep 2021 11:15:49 +02:00

x86/mce: Get rid of machine_check_vector

Get rid of the indirect function pointer and use flags settings instead
to steer execution.

Now that it is not an indirect call any longer, drop the instrumentation
annotation for objtool too.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20210922165101.18951-3-bp@alien8.de
---
 arch/x86/include/asm/mce.h         | 10 +-----
 arch/x86/kernel/cpu/mce/core.c     | 57 +++++++++++++----------------
 arch/x86/kernel/cpu/mce/internal.h | 29 ++++++++++++---
 arch/x86/kernel/cpu/mce/p5.c       |  6 +---
 arch/x86/kernel/cpu/mce/winchip.c  |  6 +---
 5 files changed, 53 insertions(+), 55 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 258ef6d..813b4f5 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -215,16 +215,6 @@ static inline int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info,
 					     u64 lapic_id) { return -EINVAL; }
 #endif
 
-#ifdef CONFIG_X86_ANCIENT_MCE
-void intel_p5_mcheck_init(struct cpuinfo_x86 *c);
-void winchip_mcheck_init(struct cpuinfo_x86 *c);
-static inline void enable_p5_mce(void) { mce_p5_enabled = 1; }
-#else
-static inline void intel_p5_mcheck_init(struct cpuinfo_x86 *c) {}
-static inline void winchip_mcheck_init(struct cpuinfo_x86 *c) {}
-static inline void enable_p5_mce(void) {}
-#endif
-
 void mce_setup(struct mce *m);
 void mce_log(struct mce *m);
 DECLARE_PER_CPU(struct device *, mce_device);
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index aaede7e..7aff9a5 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1328,6 +1328,15 @@ static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callba
 	task_work_add(current, &current->mce_kill_me, TWA_RESUME);
 }
 
+/* Handle unconfigured int18 (should never happen) */
+static noinstr void unexpected_machine_check(struct pt_regs *regs)
+{
+	instrumentation_begin();
+	pr_err("CPU#%d: Unexpected int18 (Machine Check)\n",
+	       smp_processor_id());
+	instrumentation_end();
+}
+
 /*
  * The actual machine check handler. This only handles real
  * exceptions when something got corrupted coming in through int 18.
@@ -1348,36 +1357,43 @@ static void queue_task_work(struct mce *m, char *msg, void (*func)(struct callba
  */
 noinstr void do_machine_check(struct pt_regs *regs)
 {
+	int worst = 0, order, no_way_out, kill_current_task, lmce;
 	DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
 	DECLARE_BITMAP(toclear, MAX_NR_BANKS);
 	struct mca_config *cfg = &mca_cfg;
 	struct mce m, *final;
 	char *msg = NULL;
-	int worst = 0;
+
+	if (unlikely(mce_flags.p5))
+		return pentium_machine_check(regs);
+	else if (unlikely(mce_flags.winchip))
+		return winchip_machine_check(regs);
+	else if (unlikely(!mca_cfg.initialized))
+		return unexpected_machine_check(regs);
 
 	/*
 	 * Establish sequential order between the CPUs entering the machine
 	 * check handler.
 	 */
-	int order = -1;
+	order = -1;
 
 	/*
 	 * If no_way_out gets set, there is no safe way to recover from this
 	 * MCE.  If mca_cfg.tolerant is cranked up, we'll try anyway.
 	 */
-	int no_way_out = 0;
+	no_way_out = 0;
 
 	/*
 	 * If kill_current_task is not set, there might be a way to recover from this
 	 * error.
 	 */
-	int kill_current_task = 0;
+	kill_current_task = 0;
 
 	/*
 	 * MCEs are always local on AMD. Same is determined by MCG_STATUS_LMCES
 	 * on Intel.
 	 */
-	int lmce = 1;
+	lmce = 1;
 
 	this_cpu_inc(mce_exception_count);
 
@@ -1855,9 +1871,11 @@ static int __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c)
 	switch (c->x86_vendor) {
 	case X86_VENDOR_INTEL:
 		intel_p5_mcheck_init(c);
+		mce_flags.p5 = 1;
 		return 1;
 	case X86_VENDOR_CENTAUR:
 		winchip_mcheck_init(c);
+		mce_flags.winchip = 1;
 		return 1;
 	default:
 		return 0;
@@ -2012,18 +2030,6 @@ bool filter_mce(struct mce *m)
 	return false;
 }
 
-/* Handle unconfigured int18 (should never happen) */
-static noinstr void unexpected_machine_check(struct pt_regs *regs)
-{
-	instrumentation_begin();
-	pr_err("CPU#%d: Unexpected int18 (Machine Check)\n",
-	       smp_processor_id());
-	instrumentation_end();
-}
-
-/* Call the installed machine check handler for this CPU setup. */
-void (*machine_check_vector)(struct pt_regs *) = unexpected_machine_check;
-
 static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
 {
 	irqentry_state_t irq_state;
@@ -2034,31 +2040,22 @@ static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
 	 * Only required when from kernel mode. See
 	 * mce_check_crashing_cpu() for details.
 	 */
-	if (machine_check_vector == do_machine_check &&
-	    mce_check_crashing_cpu())
+	if (mca_cfg.initialized && mce_check_crashing_cpu())
 		return;
 
 	irq_state = irqentry_nmi_enter(regs);
-	/*
-	 * The call targets are marked noinstr, but objtool can't figure
-	 * that out because it's an indirect call. Annotate it.
-	 */
-	instrumentation_begin();
 
-	machine_check_vector(regs);
+	do_machine_check(regs);
 
-	instrumentation_end();
 	irqentry_nmi_exit(regs, irq_state);
 }
 
 static __always_inline void exc_machine_check_user(struct pt_regs *regs)
 {
 	irqentry_enter_from_user_mode(regs);
-	instrumentation_begin();
 
-	machine_check_vector(regs);
+	do_machine_check(regs);
 
-	instrumentation_end();
 	irqentry_exit_to_user_mode(regs);
 }
 
@@ -2125,7 +2122,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
 		return;
 	}
 
-	machine_check_vector = do_machine_check;
+	mca_cfg.initialized = 1;
 
 	__mcheck_cpu_init_early(c);
 	__mcheck_cpu_init_generic();
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 09cb5ab..d71d6c5 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -8,9 +8,6 @@
 #include <linux/device.h>
 #include <asm/mce.h>
 
-/* Pointer to the installed machine check handler for this CPU setup. */
-extern void (*machine_check_vector)(struct pt_regs *);
-
 enum severity_level {
 	MCE_NO_SEVERITY,
 	MCE_DEFERRED_SEVERITY,
@@ -126,7 +123,9 @@ struct mca_config {
 	      ser			: 1,
 	      recovery			: 1,
 	      bios_cmci_threshold	: 1,
-	      __reserved		: 59;
+	      /* Proper #MC exception handler is set */
+	      initialized		: 1,
+	      __reserved		: 58;
 
 	s8 bootlog;
 	int tolerant;
@@ -162,7 +161,13 @@ struct mce_vendor_flags {
 	/* AMD-style error thresholding banks present. */
 	amd_threshold		: 1,
 
-	__reserved_0		: 60;
+	/* Pentium, family 5-style MCA */
+	p5			: 1,
+
+	/* Centaur Winchip C6-style MCA */
+	winchip			: 1,
+
+	__reserved_0		: 58;
 };
 
 extern struct mce_vendor_flags mce_flags;
@@ -195,4 +200,18 @@ __visible bool ex_handler_wrmsr_fault(const struct exception_table_entry *fixup,
 				      unsigned long error_code,
 				      unsigned long fault_addr);
 
+#ifdef CONFIG_X86_ANCIENT_MCE
+void intel_p5_mcheck_init(struct cpuinfo_x86 *c);
+void winchip_mcheck_init(struct cpuinfo_x86 *c);
+noinstr void pentium_machine_check(struct pt_regs *regs);
+noinstr void winchip_machine_check(struct pt_regs *regs);
+static inline void enable_p5_mce(void) { mce_p5_enabled = 1; }
+#else
+static inline void intel_p5_mcheck_init(struct cpuinfo_x86 *c) {}
+static inline void winchip_mcheck_init(struct cpuinfo_x86 *c) {}
+static inline void enable_p5_mce(void) {}
+static inline void pentium_machine_check(struct pt_regs *regs) {}
+static inline void winchip_machine_check(struct pt_regs *regs) {}
+#endif
+
 #endif /* __X86_MCE_INTERNAL_H__ */
diff --git a/arch/x86/kernel/cpu/mce/p5.c b/arch/x86/kernel/cpu/mce/p5.c
index 19e90ca..2272ad5 100644
--- a/arch/x86/kernel/cpu/mce/p5.c
+++ b/arch/x86/kernel/cpu/mce/p5.c
@@ -21,7 +21,7 @@
 int mce_p5_enabled __read_mostly;
 
 /* Machine check handler for Pentium class Intel CPUs: */
-static noinstr void pentium_machine_check(struct pt_regs *regs)
+noinstr void pentium_machine_check(struct pt_regs *regs)
 {
 	u32 loaddr, hi, lotype;
 
@@ -54,10 +54,6 @@ void intel_p5_mcheck_init(struct cpuinfo_x86 *c)
 	if (!cpu_has(c, X86_FEATURE_MCE))
 		return;
 
-	machine_check_vector = pentium_machine_check;
-	/* Make sure the vector pointer is visible before we enable MCEs: */
-	wmb();
-
 	/* Read registers before enabling: */
 	rdmsr(MSR_IA32_P5_MC_ADDR, l, h);
 	rdmsr(MSR_IA32_P5_MC_TYPE, l, h);
diff --git a/arch/x86/kernel/cpu/mce/winchip.c b/arch/x86/kernel/cpu/mce/winchip.c
index 9c9f0ab..6c99f29 100644
--- a/arch/x86/kernel/cpu/mce/winchip.c
+++ b/arch/x86/kernel/cpu/mce/winchip.c
@@ -17,7 +17,7 @@
 #include "internal.h"
 
 /* Machine check handler for WinChip C6: */
-static noinstr void winchip_machine_check(struct pt_regs *regs)
+noinstr void winchip_machine_check(struct pt_regs *regs)
 {
 	instrumentation_begin();
 	pr_emerg("CPU0: Machine Check Exception.\n");
@@ -30,10 +30,6 @@ void winchip_mcheck_init(struct cpuinfo_x86 *c)
 {
 	u32 lo, hi;
 
-	machine_check_vector = winchip_machine_check;
-	/* Make sure the vector pointer is visible before we enable MCEs: */
-	wmb();
-
 	rdmsr(MSR_IDT_FCR1, lo, hi);
 	lo |= (1<<2);	/* Enable EIERRINT (int 18 MCE) */
 	lo &= ~(1<<4);	/* Enable MCE */

[tip: ras/core] x86/mce: Get rid of the mce_severity function pointer

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the ras/core branch of tip:

Commit-ID:     631adc7b0bbaa1333fc39f0dca5e7584f51d86c9
Gitweb:        https://git.kernel.org/tip/631adc7b0bbaa1333fc39f0dca5e7584f51d86c9
Author:        Borislav Petkov <bp@suse.de>
AuthorDate:    Wed, 01 Sep 2021 17:02:58 +02:00
Committer:     Borislav Petkov <bp@suse.de>
CommitterDate: Thu, 23 Sep 2021 11:03:51 +02:00

x86/mce: Get rid of the mce_severity function pointer

Turn it into a normal function which calls an AMD- or Intel-specific
variant depending on the CPU it runs on.

No functional changes.

Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20210922165101.18951-2-bp@alien8.de
---
 arch/x86/include/asm/mce.h         |  2 --
 arch/x86/kernel/cpu/mce/core.c     |  1 -
 arch/x86/kernel/cpu/mce/internal.h |  3 +--
 arch/x86/kernel/cpu/mce/severity.c | 11 +++++------
 4 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index da93215..258ef6d 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -205,14 +205,12 @@ struct cper_ia_proc_ctx;
 int mcheck_init(void);
 void mcheck_cpu_init(struct cpuinfo_x86 *c);
 void mcheck_cpu_clear(struct cpuinfo_x86 *c);
-void mcheck_vendor_init_severity(void);
 int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info,
 			       u64 lapic_id);
 #else
 static inline int mcheck_init(void) { return 0; }
 static inline void mcheck_cpu_init(struct cpuinfo_x86 *c) {}
 static inline void mcheck_cpu_clear(struct cpuinfo_x86 *c) {}
-static inline void mcheck_vendor_init_severity(void) {}
 static inline int apei_smca_report_x86_error(struct cper_ia_proc_ctx *ctx_info,
 					     u64 lapic_id) { return -EINVAL; }
 #endif
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 69768fe..aaede7e 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -2233,7 +2233,6 @@ int __init mcheck_init(void)
 	mce_register_decode_chain(&early_nb);
 	mce_register_decode_chain(&mce_uc_nb);
 	mce_register_decode_chain(&mce_default_nb);
-	mcheck_vendor_init_severity();
 
 	INIT_WORK(&mce_work, mce_gen_pool_process);
 	init_irq_work(&mce_irq_work, mce_irq_work_cb);
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 88dcc79..09cb5ab 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -38,8 +38,7 @@ int mce_gen_pool_add(struct mce *mce);
 int mce_gen_pool_init(void);
 struct llist_node *mce_gen_pool_prepare_records(void);
 
-extern int (*mce_severity)(struct mce *a, struct pt_regs *regs,
-			   int tolerant, char **msg, bool is_excp);
+int mce_severity(struct mce *a, struct pt_regs *regs, int tolerant, char **msg, bool is_excp);
 struct dentry *mce_get_debugfs_dir(void);
 
 extern mce_banks_t mce_banks_ce_disabled;
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index 17e6314..695570f 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -407,15 +407,14 @@ static int mce_severity_intel(struct mce *m, struct pt_regs *regs,
 	}
 }
 
-/* Default to mce_severity_intel */
-int (*mce_severity)(struct mce *m, struct pt_regs *regs, int tolerant, char **msg, bool is_excp) =
-		    mce_severity_intel;
-
-void __init mcheck_vendor_init_severity(void)
+int mce_severity(struct mce *m, struct pt_regs *regs, int tolerant, char **msg,
+		 bool is_excp)
 {
 	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
 	    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
-		mce_severity = mce_severity_amd;
+		return mce_severity_amd(m, regs, tolerant, msg, is_excp);
+	else
+		return mce_severity_intel(m, regs, tolerant, msg, is_excp);
 }
 
 #ifdef CONFIG_DEBUG_FS