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

From: Borislav Petkov
Date: Wed Sep 22 2021 - 12:51:12 EST


From: Borislav Petkov <bp@xxxxxxx>

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@xxxxxxx>
---
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