cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr
* This patch replaces the dangerous lvalue version of cpumask_of_cpu
with new cpumask_of_cpu_ptr macros. These are patterned after the
node_to_cpumask_ptr macros.
In general terms, if there is a cpumask_of_cpu_map[] then a pointer to
the cpumask_of_cpu_map[cpu] entry is used. The cpumask_of_cpu_map
is provided when there is a large NR_CPUS count, reducing
greatly the amount of code generated and stack space used for
cpumask_of_cpu(). The pointer to the cpumask_t value is needed for
calling set_cpus_allowed_ptr() to reduce the amount of stack space
needed to pass the cpumask_t value.
If there isn't a cpumask_of_cpu_map[], then a temporary variable is
declared and filled in with value from cpumask_of_cpu(cpu) as well as
a pointer variable pointing to this temporary variable. Afterwards,
the pointer is used to reference the cpumask value. The compiler
will optimize out the extra dereference through the pointer as well
as the stack space used for the pointer, resulting in identical code.
A good example of the orthogonal usages is in net/sunrpc/svc.c:
case SVC_POOL_PERCPU:
{
unsigned int cpu = m->pool_to[pidx];
cpumask_of_cpu_ptr(cpumask, cpu);
*oldmask = current->cpus_allowed;
set_cpus_allowed_ptr(current, cpumask);
return 1;
}
case SVC_POOL_PERNODE:
{
unsigned int node = m->pool_to[pidx];
node_to_cpumask_ptr(nodecpumask, node);
*oldmask = current->cpus_allowed;
set_cpus_allowed_ptr(current, nodecpumask);
return 1;
}
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index c2502eb..9220cf4 100644
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -73,6 +73,7 @@
struct cpuinfo_x86 *c = &cpu_data(cpu);
cpumask_t saved_mask;
+ cpumask_of_cpu_ptr(new_mask, cpu);
int retval;
unsigned int eax, ebx, ecx, edx;
unsigned int edx_part;
@@ -91,7 +92,7 @@
/* Make sure we are running on right CPU */
saved_mask = current->cpus_allowed;
- retval = set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ retval = set_cpus_allowed_ptr(current, new_mask);
if (retval)
return -1;
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index dd097b8..ff2fff5 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -200,10 +200,12 @@
static void drv_write(struct drv_cmd *cmd)
{
cpumask_t saved_mask = current->cpus_allowed;
+ cpumask_of_cpu_ptr_declare(cpu_mask);
unsigned int i;
for_each_cpu_mask_nr(i, cmd->mask) {
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(i));
+ cpumask_of_cpu_ptr_next(cpu_mask, i);
+ set_cpus_allowed_ptr(current, cpu_mask);
do_drv_write(cmd);
}
@@ -267,11 +269,12 @@
} aperf_cur, mperf_cur;
cpumask_t saved_mask;
+ cpumask_of_cpu_ptr(cpu_mask, cpu);
unsigned int perf_percent;
unsigned int retval;
saved_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, cpu_mask);
if (get_cpu() != cpu) {
/* We were not able to run on requested processor */
put_cpu();
@@ -337,6 +340,7 @@
static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
{
+ cpumask_of_cpu_ptr(cpu_mask, cpu);
struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
unsigned int freq;
unsigned int cached_freq;
@@ -349,7 +353,7 @@
}
cached_freq = data->freq_table[data->acpi_data->state].frequency;
- freq = extract_freq(get_cur_val(&cpumask_of_cpu(cpu)), data);
+ freq = extract_freq(get_cur_val(cpu_mask), data);
if (freq != cached_freq) {
/*
* The dreaded BIOS frequency change behind our back.
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index c45ca6d..53c7b69 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -479,11 +479,12 @@
static int check_supported_cpu(unsigned int cpu)
{
cpumask_t oldmask;
+ cpumask_of_cpu_ptr(cpu_mask, cpu);
u32 eax, ebx, ecx, edx;
unsigned int rc = 0;
oldmask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, cpu_mask);
if (smp_processor_id() != cpu) {
printk(KERN_ERR PFX "limiting to cpu %u failed\n", cpu);
@@ -1016,6 +1017,7 @@
static int powernowk8_target(struct cpufreq_policy *pol, unsigned targfreq, unsigned relation)
{
cpumask_t oldmask;
+ cpumask_of_cpu_ptr(cpu_mask, pol->cpu);
struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
u32 checkfid;
u32 checkvid;
@@ -1030,7 +1032,7 @@
/* only run on specific CPU from here on */
oldmask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu));
+ set_cpus_allowed_ptr(current, cpu_mask);
if (smp_processor_id() != pol->cpu) {
printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
@@ -1105,6 +1107,7 @@
{
struct powernow_k8_data *data;
cpumask_t oldmask;
+ cpumask_of_cpu_ptr_declare(newmask);
int rc;
if (!cpu_online(pol->cpu))
@@ -1156,7 +1159,8 @@
/* only run on specific CPU from here on */
oldmask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu));
+ cpumask_of_cpu_ptr_next(newmask, pol->cpu);
+ set_cpus_allowed_ptr(current, newmask);
if (smp_processor_id() != pol->cpu) {
printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
@@ -1178,7 +1182,7 @@
set_cpus_allowed_ptr(current, &oldmask);
if (cpu_family == CPU_HW_PSTATE)
- pol->cpus = cpumask_of_cpu(pol->cpu);
+ pol->cpus = *newmask;
else
pol->cpus = per_cpu(cpu_core_map, pol->cpu);
data->available_cores = &(pol->cpus);
@@ -1244,6 +1248,7 @@
{
struct powernow_k8_data *data;
cpumask_t oldmask = current->cpus_allowed;
+ cpumask_of_cpu_ptr(newmask, cpu);
unsigned int khz = 0;
unsigned int first;
@@ -1253,7 +1258,7 @@
if (!data)
return -EINVAL;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, newmask);
if (smp_processor_id() != cpu) {
printk(KERN_ERR PFX
"limiting to CPU %d failed in powernowk8_get\n", cpu);
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
index 8b0dd6f..fd561bb 100644
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-centrino.c
@@ -313,9 +313,10 @@
unsigned l, h;
unsigned clock_freq;
cpumask_t saved_mask;
+ cpumask_of_cpu_ptr(new_mask, cpu);
saved_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, new_mask);
if (smp_processor_id() != cpu)
return 0;
@@ -554,9 +555,11 @@
*/
if (!cpus_empty(covered_cpus)) {
+ cpumask_of_cpu_ptr_declare(new_mask);
+
for_each_cpu_mask_nr(j, covered_cpus) {
- set_cpus_allowed_ptr(current,
- &cpumask_of_cpu(j));
+ cpumask_of_cpu_ptr_next(new_mask, j);
+ set_cpus_allowed_ptr(current, new_mask);
wrmsr(MSR_IA32_PERF_CTL, oldmsr, h);
}
}
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c b/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c
index 191f726..2f3728d 100644
--- a/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-ich.c
@@ -244,7 +244,8 @@
static unsigned int speedstep_get(unsigned int cpu)
{
- return _speedstep_get(&cpumask_of_cpu(cpu));
+ cpumask_of_cpu_ptr(newmask, cpu);
+ return _speedstep_get(newmask);
}
/**
diff --git a/arch/x86/kernel/cpu/intel_cacheinfo.c b/arch/x86/kernel/cpu/intel_cacheinfo.c
index a7b0f8f..e4b8d18 100644
--- a/arch/x86/kernel/cpu/intel_cacheinfo.c
+++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
@@ -516,6 +516,7 @@
unsigned long j;
int retval;
cpumask_t oldmask;
+ cpumask_of_cpu_ptr(newmask, cpu);
if (num_cache_leaves == 0)
return -ENOENT;
@@ -526,7 +527,7 @@
return -ENOMEM;
oldmask = current->cpus_allowed;
- retval = set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ retval = set_cpus_allowed_ptr(current, newmask);
if (retval)
goto out;
diff --git a/arch/x86/kernel/microcode.c b/arch/x86/kernel/microcode.c
index 56b9331..5852016 100644
--- a/arch/x86/kernel/microcode.c
+++ b/arch/x86/kernel/microcode.c
@@ -388,6 +388,7 @@
void *new_mc = NULL;
int cpu;
cpumask_t old;
+ cpumask_of_cpu_ptr_declare(newmask);
old = current->cpus_allowed;
@@ -404,7 +405,8 @@
if (!uci->valid)
continue;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ cpumask_of_cpu_ptr_next(newmask, cpu);
+ set_cpus_allowed_ptr(current, newmask);
error = get_maching_microcode(new_mc, cpu);
if (error < 0)
goto out;
@@ -574,6 +576,7 @@
struct cpuinfo_x86 *c = &cpu_data(cpu);
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
cpumask_t old;
+ cpumask_of_cpu_ptr(newmask, cpu);
unsigned int val[2];
int err = 0;
@@ -582,7 +585,7 @@
return 0;
old = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, newmask);
/* Check if the microcode we have in memory matches the CPU */
if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
@@ -620,11 +623,12 @@
static void microcode_init_cpu(int cpu, int resume)
{
cpumask_t old;
+ cpumask_of_cpu_ptr(newmask, cpu);
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
old = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, newmask);
mutex_lock(µcode_mutex);
collect_cpu_info(cpu);
if (uci->valid && system_state == SYSTEM_RUNNING && !resume)
@@ -656,11 +660,12 @@
return -EINVAL;
if (val == 1) {
cpumask_t old;
+ cpumask_of_cpu_ptr(newmask, cpu);
old = current->cpus_allowed;
get_online_cpus();
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, newmask);
mutex_lock(µcode_mutex);
if (uci->valid)
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index f8a6216..214bbdf 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -403,24 +403,28 @@
{
/* Stop the cpus and apics */
#ifdef CONFIG_SMP
- int reboot_cpu_id;
/* The boot cpu is always logical cpu 0 */
- reboot_cpu_id = 0;
+ int reboot_cpu_id = 0;
+ cpumask_of_cpu_ptr(newmask, reboot_cpu_id);
#ifdef CONFIG_X86_32
/* See if there has been given a command line override */
if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
- cpu_online(reboot_cpu))
+ cpu_online(reboot_cpu)) {
reboot_cpu_id = reboot_cpu;
+ cpumask_of_cpu_ptr_next(newmask, reboot_cpu_id);
+ }
#endif
/* Make certain the cpu I'm about to reboot on is online */
- if (!cpu_online(reboot_cpu_id))
+ if (!cpu_online(reboot_cpu_id)) {
reboot_cpu_id = smp_processor_id();
+ cpumask_of_cpu_ptr_next(newmask, reboot_cpu_id);
+ }
/* Make certain I only run on the appropriate processor */
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
+ set_cpus_allowed_ptr(current, newmask);
/* O.K Now that I'm on the appropriate processor,
* stop all of the others.
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index a56fc6c..a2c3f9c 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -827,6 +827,7 @@
static int acpi_processor_get_throttling(struct acpi_processor *pr)
{
cpumask_t saved_mask;
+ cpumask_of_cpu_ptr_declare(new_mask);
int ret;
if (!pr)
@@ -838,7 +839,8 @@
* Migrate task to the cpu pointed by pr.
*/
saved_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(pr->id));
+ cpumask_of_cpu_ptr_next(new_mask, pr->id);
+ set_cpus_allowed_ptr(current, new_mask);
ret = pr->throttling.acpi_processor_get_throttling(pr);
/* restore the previous state */
set_cpus_allowed_ptr(current, &saved_mask);
@@ -987,6 +989,7 @@
int acpi_processor_set_throttling(struct acpi_processor *pr, int state)
{
cpumask_t saved_mask;
+ cpumask_of_cpu_ptr_declare(new_mask);
int ret = 0;
unsigned int i;
struct acpi_processor *match_pr;
@@ -1025,7 +1028,8 @@
* it can be called only for the cpu pointed by pr.
*/
if (p_throttling->shared_type == DOMAIN_COORD_TYPE_SW_ANY) {
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(pr->id));
+ cpumask_of_cpu_ptr_next(new_mask, pr->id);
+ set_cpus_allowed_ptr(current, new_mask);
ret = p_throttling->acpi_processor_set_throttling(pr,
t_state.target_state);
} else {
@@ -1056,7 +1060,8 @@
continue;
}
t_state.cpu = i;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(i));
+ cpumask_of_cpu_ptr_next(new_mask, i);
+ set_cpus_allowed_ptr(current, new_mask);
ret = match_pr->throttling.
acpi_processor_set_throttling(
match_pr, t_state.target_state);
diff --git a/drivers/firmware/dcdbas.c b/drivers/firmware/dcdbas.c
index 25918f7..0b624e9 100644
--- a/drivers/firmware/dcdbas.c
+++ b/drivers/firmware/dcdbas.c
@@ -254,6 +254,7 @@
static int smi_request(struct smi_cmd *smi_cmd)
{
cpumask_t old_mask;
+ cpumask_of_cpu_ptr(new_mask, 0);
int ret = 0;
if (smi_cmd->magic != SMI_CMD_MAGIC) {
@@ -264,7 +265,7 @@
/* SMI requires CPU 0 */
old_mask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(0));
+ set_cpus_allowed_ptr(current, new_mask);
if (smp_processor_id() != 0) {
dev_dbg(&dcdbas_pdev->dev, "%s: failed to get CPU 0\n",
__func__);
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 80226e7..2dbd9a2 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -62,6 +62,15 @@
* int next_cpu_nr(cpu, mask) Next cpu past 'cpu', or nr_cpu_ids
*
* cpumask_t cpumask_of_cpu(cpu) Return cpumask with bit 'cpu' set
+ *ifdef CONFIG_HAS_CPUMASK_OF_CPU
+ * cpumask_of_cpu_ptr_declare(v) Declares cpumask_t *v
+ * cpumask_of_cpu_ptr_next(v, cpu) Sets v = &cpumask_of_cpu_map[cpu]
+ * cpumask_of_cpu_ptr(v, cpu) Combines above two operations
+ *else
+ * cpumask_of_cpu_ptr_declare(v) Declares cpumask_t _v and *v = &_v
+ * cpumask_of_cpu_ptr_next(v, cpu) Sets _v = cpumask_of_cpu(cpu)
+ * cpumask_of_cpu_ptr(v, cpu) Combines above two operations
+ *endif
* CPU_MASK_ALL Initializer - all bits set
* CPU_MASK_NONE Initializer - no bits set
* unsigned long *cpus_addr(mask) Array of unsigned long's in mask
@@ -236,11 +245,16 @@
#ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
extern cpumask_t *cpumask_of_cpu_map;
-#define cpumask_of_cpu(cpu) (cpumask_of_cpu_map[cpu])
-
+#define cpumask_of_cpu(cpu) (cpumask_of_cpu_map[cpu])
+#define cpumask_of_cpu_ptr(v, cpu) \
+ const cpumask_t *v = &cpumask_of_cpu(cpu)
+#define cpumask_of_cpu_ptr_declare(v) \
+ const cpumask_t *v
+#define cpumask_of_cpu_ptr_next(v, cpu) \
+ v = &cpumask_of_cpu(cpu)
#else
#define cpumask_of_cpu(cpu) \
-(*({ \
+({ \
typeof(_unused_cpumask_arg_) m; \
if (sizeof(m) == sizeof(unsigned long)) { \
m.bits[0] = 1UL<<(cpu); \
@@ -248,8 +262,16 @@
cpus_clear(m); \
cpu_set((cpu), m); \
} \
- &m; \
-}))
+ m; \
+})
+#define cpumask_of_cpu_ptr(v, cpu) \
+ cpumask_t _##v = cpumask_of_cpu(cpu); \
+ const cpumask_t *v = &_##v
+#define cpumask_of_cpu_ptr_declare(v) \
+ cpumask_t _##v; \
+ const cpumask_t *v = &_##v
+#define cpumask_of_cpu_ptr_next(v, cpu) \
+ _##v = cpumask_of_cpu(cpu)
#endif
#define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index ba9b205..738b411 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -33,8 +33,9 @@
{
int irqs_disabled = 0;
int prepared = 0;
+ cpumask_of_cpu_ptr(cpumask, (int)(long)cpu);
- set_cpus_allowed_ptr(current, &cpumask_of_cpu((int)(long)cpu));
+ set_cpus_allowed_ptr(current, cpumask);
/* Ack: we are alive */
smp_mb(); /* Theoretically the ack = 0 might not be on this CPU yet. */
diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c
index 2301e1e..6352808 100644
--- a/kernel/trace/trace_sysprof.c
+++ b/kernel/trace/trace_sysprof.c
@@ -213,7 +213,9 @@
int cpu;
for_each_online_cpu(cpu) {
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ cpumask_of_cpu_ptr(new_mask, cpu);
+
+ set_cpus_allowed_ptr(current, new_mask);
start_stack_timer(cpu);
}
set_cpus_allowed_ptr(current, &saved_mask);
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index d43cf8d..083d126 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -314,9 +314,10 @@
case SVC_POOL_PERCPU:
{
unsigned int cpu = m->pool_to[pidx];
+ cpumask_of_cpu_ptr(cpumask, cpu);
*oldmask = current->cpus_allowed;
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
+ set_cpus_allowed_ptr(current, cpumask);
return 1;
}
case SVC_POOL_PERNODE: