From: Laurent Vivier <[email protected]>
This patch defines the missing function smp_call_function_mask() for x86_64,
this is more or less a cut&paste of i386 function. It removes also some
duplicate code.
This function is needed by KVM to execute a function on some CPUs.
AK: Fixed description
AK: Moved WARN_ON(irqs_disabled) one level up to not warn in the panic case.
arch/x86_64/kernel/smp.c | 118 ++++++++++++++++++++++++-----------------------
include/asm-x86_64/smp.h | 2
arch/x86_64/kernel/smp.c | 119 ++++++++++++++++++++++++-----------------------
include/asm-x86_64/smp.h | 2
2 files changed, 65 insertions(+), 56 deletions(-)
Signed-off-by: Laurent Vivier <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>
Index: linux/arch/x86_64/kernel/smp.c
===================================================================
--- linux.orig/arch/x86_64/kernel/smp.c
+++ linux/arch/x86_64/kernel/smp.c
@@ -322,17 +322,27 @@ void unlock_ipi_call_lock(void)
}
/*
- * this function sends a 'generic call function' IPI to one other CPU
- * in the system.
- *
- * cpu is a standard Linux logical CPU number.
+ * this function sends a 'generic call function' IPI to all other CPU
+ * of the system defined in the mask.
*/
-static void
-__smp_call_function_single(int cpu, void (*func) (void *info), void *info,
- int nonatomic, int wait)
+
+static int
+__smp_call_function_mask(cpumask_t mask,
+ void (*func)(void *), void *info,
+ int wait)
{
struct call_data_struct data;
- int cpus = 1;
+ cpumask_t allbutself;
+ int cpus;
+
+ allbutself = cpu_online_map;
+ cpu_clear(smp_processor_id(), allbutself);
+
+ cpus_and(mask, mask, allbutself);
+ cpus = cpus_weight(mask);
+
+ if (!cpus)
+ return 0;
data.func = func;
data.info = info;
@@ -343,19 +353,55 @@ __smp_call_function_single(int cpu, void
call_data = &data;
wmb();
- /* Send a message to all other CPUs and wait for them to respond */
- send_IPI_mask(cpumask_of_cpu(cpu), CALL_FUNCTION_VECTOR);
+
+ /* Send a message to other CPUs */
+ if (cpus_equal(mask, allbutself))
+ send_IPI_allbutself(CALL_FUNCTION_VECTOR);
+ else
+ send_IPI_mask(mask, CALL_FUNCTION_VECTOR);
/* Wait for response */
while (atomic_read(&data.started) != cpus)
cpu_relax();
if (!wait)
- return;
+ return 0;
while (atomic_read(&data.finished) != cpus)
cpu_relax();
+
+ return 0;
+}
+/**
+ * smp_call_function_mask(): Run a function on a set of other CPUs.
+ * @mask: The set of cpus to run on. Must not include the current cpu.
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed on other CPUs.
+ *
+ * Returns 0 on success, else a negative status code.
+ *
+ * If @wait is true, then returns once @func has returned; otherwise
+ * it returns just before the target cpu calls @func.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int smp_call_function_mask(cpumask_t mask,
+ void (*func)(void *), void *info,
+ int wait)
+{
+ int ret;
+
+ /* Can deadlock when called with interrupts disabled */
+ WARN_ON(irqs_disabled());
+
+ spin_lock(&call_lock);
+ ret = __smp_call_function_mask(mask, func, info, wait);
+ spin_unlock(&call_lock);
+ return ret;
}
+EXPORT_SYMBOL(smp_call_function_mask);
/*
* smp_call_function_single - Run a function on a specific CPU
@@ -374,6 +420,7 @@ int smp_call_function_single (int cpu, v
int nonatomic, int wait)
{
/* prevent preemption and reschedule on another processor */
+ int ret;
int me = get_cpu();
/* Can deadlock when called with interrupts disabled */
@@ -387,51 +434,14 @@ int smp_call_function_single (int cpu, v
return 0;
}
- spin_lock(&call_lock);
- __smp_call_function_single(cpu, func, info, nonatomic, wait);
- spin_unlock(&call_lock);
+ ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, wait);
+
put_cpu();
- return 0;
+ return ret;
}
EXPORT_SYMBOL(smp_call_function_single);
/*
- * this function sends a 'generic call function' IPI to all other CPUs
- * in the system.
- */
-static void __smp_call_function (void (*func) (void *info), void *info,
- int nonatomic, int wait)
-{
- struct call_data_struct data;
- int cpus = num_online_cpus()-1;
-
- if (!cpus)
- return;
-
- data.func = func;
- data.info = info;
- atomic_set(&data.started, 0);
- data.wait = wait;
- if (wait)
- atomic_set(&data.finished, 0);
-
- call_data = &data;
- wmb();
- /* Send a message to all other CPUs and wait for them to respond */
- send_IPI_allbutself(CALL_FUNCTION_VECTOR);
-
- /* Wait for response */
- while (atomic_read(&data.started) != cpus)
- cpu_relax();
-
- if (!wait)
- return;
-
- while (atomic_read(&data.finished) != cpus)
- cpu_relax();
-}
-
-/*
* smp_call_function - run a function on all other CPUs.
* @func: The function to run. This must be fast and non-blocking.
* @info: An arbitrary pointer to pass to the function.
@@ -449,10 +459,7 @@ static void __smp_call_function (void (*
int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
int wait)
{
- spin_lock(&call_lock);
- __smp_call_function(func,info,nonatomic,wait);
- spin_unlock(&call_lock);
- return 0;
+ return smp_call_function_mask(cpu_online_map, func, info, wait);
}
EXPORT_SYMBOL(smp_call_function);
@@ -479,7 +486,7 @@ void smp_send_stop(void)
/* Don't deadlock on the call lock in panic */
nolock = !spin_trylock(&call_lock);
local_irq_save(flags);
- __smp_call_function(stop_this_cpu, NULL, 0, 0);
+ __smp_call_function_mask(cpu_online_map, stop_this_cpu, NULL, 0);
if (!nolock)
spin_unlock(&call_lock);
disable_local_APIC();
Index: linux/include/asm-x86_64/smp.h
===================================================================
--- linux.orig/include/asm-x86_64/smp.h
+++ linux/include/asm-x86_64/smp.h
@@ -37,6 +37,8 @@ extern void lock_ipi_call_lock(void);
extern void unlock_ipi_call_lock(void);
extern int smp_num_siblings;
extern void smp_send_reschedule(int cpu);
+extern int smp_call_function_mask(cpumask_t mask, void (*func)(void *),
+ void *info, int wait);
extern cpumask_t cpu_sibling_map[NR_CPUS];
extern cpumask_t cpu_core_map[NR_CPUS];
-
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