[PATCH 5/8] percpu: add __percpu sparse annotations to x86

Tejun Heo
2010-01-25T15:18:59Z

Add __percpu sparse annotations to x86.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.

In arch/x86/kernel/cpu/common.c, per_cpu(exception_stacks, cpu) is
replaced with &per_cpu(exception_stacks[0], cpu) which is equivalent
except that it allows per_cpu() macro to correctly drop percpu
designation during sparse pass.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
---
arch/x86/include/asm/msr.h | 12 +++++++-----
arch/x86/kernel/acpi/cstate.c | 2 +-
arch/x86/kernel/cpu/common.c | 2 +-
arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c | 2 +-
arch/x86/lib/msr-smp.c | 8 +++++---
arch/x86/lib/msr.c | 6 +++---
6 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index c5bc4c2..74882a5 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -30,7 +30,7 @@ struct msr {
struct msr_info {
u32 msr_no;
struct msr reg;
- struct msr *msrs;
+ struct msr __percpu *msrs;
int err;
};

@@ -256,14 +256,16 @@ do { \

#define write_rdtscp_aux(val) wrmsr(MSR_TSC_AUX, (val), 0)

-struct msr *msrs_alloc(void);
-void msrs_free(struct msr *msrs);
+struct msr __percpu *msrs_alloc(void);
+void msrs_free(struct msr __percpu *msrs);

#ifdef CONFIG_SMP
int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
-void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
-void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs);
+void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
+ struct msr __percpu *msrs);
+void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
+ struct msr __percpu *msrs);
int rdmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
int wrmsr_safe_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
int rdmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8]);
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index 2e837f5..62b0693 100644
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -61,7 +61,7 @@ struct cstate_entry {
unsigned int ecx;
} states[ACPI_PROCESSOR_MAX_POWER];
};
-static struct cstate_entry *cpu_cstate_entry; /* per CPU ptr */
+static struct cstate_entry __percpu *cpu_cstate_entry; /* per CPU ptr */

static short mwait_supported[ACPI_PROCESSOR_MAX_POWER];

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4868e4a..486cb06 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1146,7 +1146,7 @@ void __cpuinit cpu_init(void)
* set up and load the per-CPU TSS
*/
if (!oist->ist[0]) {
- char *estacks = per_cpu(exception_stacks, cpu);
+ char *estacks = &per_cpu(exception_stacks[0], cpu);

for (v = 0; v < N_EXCEPTION_STACKS; v++) {
estacks += exception_stack_sizes[v];
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index 1b1920f..61cfd75 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -73,7 +73,7 @@ static DEFINE_PER_CPU(struct acpi_cpufreq_data *, acfreq_data);
static DEFINE_PER_CPU(struct aperfmperf, acfreq_old_perf);

/* acpi_perf_data is a pointer to percpu data. */
-static struct acpi_processor_performance *acpi_perf_data;
+static struct acpi_processor_performance __percpu *acpi_perf_data;

static struct cpufreq_driver acpi_cpufreq_driver;

diff --git a/arch/x86/lib/msr-smp.c b/arch/x86/lib/msr-smp.c
index a6b1b86..b6a355f 100644
--- a/arch/x86/lib/msr-smp.c
+++ b/arch/x86/lib/msr-smp.c
@@ -64,7 +64,7 @@ int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h)
EXPORT_SYMBOL(wrmsr_on_cpu);

static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
- struct msr *msrs,
+ struct msr __percpu *msrs,
void (*msr_func) (void *info))
{
struct msr_info rv;
@@ -91,7 +91,8 @@ static void __rwmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
* @msrs: array of MSR values
*
*/
-void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
+void rdmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
+ struct msr __percpu *msrs)
{
__rwmsr_on_cpus(mask, msr_no, msrs, __rdmsr_on_cpu);
}
@@ -105,7 +106,8 @@ EXPORT_SYMBOL(rdmsr_on_cpus);
* @msrs: array of MSR values
*
*/
-void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no, struct msr *msrs)
+void wrmsr_on_cpus(const struct cpumask *mask, u32 msr_no,
+ struct msr __percpu *msrs)
{
__rwmsr_on_cpus(mask, msr_no, msrs, __wrmsr_on_cpu);
}
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index 8f8eebd..42c994c 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -2,9 +2,9 @@
#include <linux/preempt.h>
#include <asm/msr.h>

-struct msr *msrs_alloc(void)
+struct msr __percpu *msrs_alloc(void)
{
- struct msr *msrs = NULL;
+ struct msr __percpu *msrs = NULL;

msrs = alloc_percpu(struct msr);
if (!msrs) {
@@ -16,7 +16,7 @@ struct msr *msrs_alloc(void)
}
EXPORT_SYMBOL(msrs_alloc);

-void msrs_free(struct msr *msrs)
+void msrs_free(struct msr __percpu *msrs)
{
free_percpu(msrs);
}
--
1.6.4.2