From: Jan Glauber <[email protected]>
[S390] smp_call_function cleanup
Introduce __smp_call_function_map which calls a function on all cpus
given with a cpumask_t. Use it to implement smp_call_function and
smp_call_function_on. Replace smp_ext_bitcall_others with smp_ext_bitcall
and a for_each_cpu_mask loop. Use a cpumask_t instead of an atomic_t for
cpu counting and print a warning if preempt is on in
__smp_call_function_map().
Signed-off-by: Jan Glauber <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---
arch/s390/kernel/smp.c | 181 ++++++++++++++++++++-----------------------------
1 files changed, 77 insertions(+), 104 deletions(-)
diff -urpN linux-2.6/arch/s390/kernel/smp.c linux-2.6-patched/arch/s390/kernel/smp.c
--- linux-2.6/arch/s390/kernel/smp.c 2007-02-21 10:47:06.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/smp.c 2007-02-21 10:47:26.000000000 +0100
@@ -54,19 +54,18 @@ cpumask_t cpu_possible_map = CPU_MASK_NO
static struct task_struct *current_set[NR_CPUS];
static void smp_ext_bitcall(int, ec_bit_sig);
-static void smp_ext_bitcall_others(ec_bit_sig);
/*
- * Structure and data for smp_call_function(). This is designed to minimise
- * static memory requirements. It also looks cleaner.
+ * Structure and data for __smp_call_function_map(). This is designed to
+ * minimise static memory requirements. It also looks cleaner.
*/
static DEFINE_SPINLOCK(call_lock);
struct call_data_struct {
void (*func) (void *info);
void *info;
- atomic_t started;
- atomic_t finished;
+ cpumask_t started;
+ cpumask_t finished;
int wait;
};
@@ -81,118 +80,113 @@ static void do_call_function(void)
void *info = call_data->info;
int wait = call_data->wait;
- atomic_inc(&call_data->started);
+ cpu_set(smp_processor_id(), call_data->started);
(*func)(info);
if (wait)
- atomic_inc(&call_data->finished);
+ cpu_set(smp_processor_id(), call_data->finished);;
}
-/*
- * this function sends a 'generic call function' IPI to all other CPUs
- * in the system.
- */
-
-int smp_call_function (void (*func) (void *info), void *info, int nonatomic,
- int wait)
-/*
- * [SUMMARY] 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.
- * <nonatomic> currently unused.
- * <wait> If true, wait (atomically) until function has completed on other CPUs.
- * [RETURNS] 0 on success, else a negative status code. Does not return until
- * remote CPUs are nearly ready to execute <<func>> or are or have executed.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler.
- */
+static void __smp_call_function_map(void (*func) (void *info), void *info,
+ int nonatomic, int wait, cpumask_t map)
{
struct call_data_struct data;
- int cpus = num_online_cpus()-1;
+ int cpu, local = 0;
- if (cpus <= 0)
- return 0;
+ /*
+ * Can deadlock when interrupts are disabled or if in wrong context,
+ * caller must disable preemption
+ */
+ WARN_ON(irqs_disabled() || in_irq() || preemptible());
- /* Can deadlock when interrupts are disabled or if in wrong context */
- WARN_ON(irqs_disabled() || in_irq());
+ /*
+ * Check for local function call. We have to have the same call order
+ * as in on_each_cpu() because of machine_restart_smp().
+ */
+ if (cpu_isset(smp_processor_id(), map)) {
+ local = 1;
+ cpu_clear(smp_processor_id(), map);
+ }
+
+ cpus_and(map, map, cpu_online_map);
+ if (cpus_empty(map))
+ goto out;
data.func = func;
data.info = info;
- atomic_set(&data.started, 0);
+ data.started = CPU_MASK_NONE;
data.wait = wait;
if (wait)
- atomic_set(&data.finished, 0);
+ data.finished = CPU_MASK_NONE;
spin_lock_bh(&call_lock);
call_data = &data;
- /* Send a message to all other CPUs and wait for them to respond */
- smp_ext_bitcall_others(ec_call_function);
+
+ for_each_cpu_mask(cpu, map)
+ smp_ext_bitcall(cpu, ec_call_function);
/* Wait for response */
- while (atomic_read(&data.started) != cpus)
+ while (!cpus_equal(map, data.started))
cpu_relax();
if (wait)
- while (atomic_read(&data.finished) != cpus)
+ while (!cpus_equal(map, data.finished))
cpu_relax();
+
spin_unlock_bh(&call_lock);
- return 0;
+out:
+ local_irq_disable();
+ if (local)
+ func(info);
+ local_irq_enable();
}
/*
- * Call a function on one CPU
- * cpu : the CPU the function should be executed on
+ * smp_call_function:
+ * @func: the function to run; this must be fast and non-blocking
+ * @info: an arbitrary pointer to pass to the function
+ * @nonatomic: unused
+ * @wait: if true, wait (atomically) until function has completed on other CPUs
*
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler. You may call it from a bottom half.
+ * Run a function on all other CPUs.
*
- * It is guaranteed that the called function runs on the specified CPU,
- * preemption is disabled.
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler. Must be called with preemption disabled.
+ * You may call it from a bottom half.
*/
-int smp_call_function_on(void (*func) (void *info), void *info,
- int nonatomic, int wait, int cpu)
+int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
+ int wait)
{
- struct call_data_struct data;
- int curr_cpu;
-
- if (!cpu_online(cpu))
- return -EINVAL;
-
- /* Can deadlock when interrupts are disabled or if in wrong context */
- WARN_ON(irqs_disabled() || in_irq());
-
- /* disable preemption for local function call */
- curr_cpu = get_cpu();
-
- if (curr_cpu == cpu) {
- /* direct call to function */
- func(info);
- put_cpu();
- return 0;
- }
-
- data.func = func;
- data.info = info;
- atomic_set(&data.started, 0);
- data.wait = wait;
- if (wait)
- atomic_set(&data.finished, 0);
-
- spin_lock_bh(&call_lock);
- call_data = &data;
- smp_ext_bitcall(cpu, ec_call_function);
+ cpumask_t map;
- /* Wait for response */
- while (atomic_read(&data.started) != 1)
- cpu_relax();
+ map = cpu_online_map;
+ cpu_clear(smp_processor_id(), map);
+ __smp_call_function_map(func, info, nonatomic, wait, map);
+ return 0;
+}
+EXPORT_SYMBOL(smp_call_function);
- if (wait)
- while (atomic_read(&data.finished) != 1)
- cpu_relax();
+/*
+ * smp_call_function_on:
+ * @func: the function to run; this must be fast and non-blocking
+ * @info: an arbitrary pointer to pass to the function
+ * @nonatomic: unused
+ * @wait: if true, wait (atomically) until function has completed on other CPUs
+ * @cpu: the CPU where func should run
+ *
+ * Run a function on one processor.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler. Must be called with preemption disabled.
+ * You may call it from a bottom half.
+ */
+int smp_call_function_on(void (*func) (void *info), void *info, int nonatomic,
+ int wait, int cpu)
+{
+ cpumask_t map = CPU_MASK_NONE;
- spin_unlock_bh(&call_lock);
- put_cpu();
+ cpu_set(cpu, map);
+ __smp_call_function_map(func, info, nonatomic, wait, map);
return 0;
}
EXPORT_SYMBOL(smp_call_function_on);
@@ -325,26 +319,6 @@ static void smp_ext_bitcall(int cpu, ec_
udelay(10);
}
-/*
- * Send an external call sigp to every other cpu in the system and
- * return without waiting for its completion.
- */
-static void smp_ext_bitcall_others(ec_bit_sig sig)
-{
- int cpu;
-
- for_each_online_cpu(cpu) {
- if (cpu == smp_processor_id())
- continue;
- /*
- * Set signaling bit in lowcore of target cpu and kick it
- */
- set_bit(sig, (unsigned long *) &lowcore_ptr[cpu]->ext_call_fast);
- while (signal_processor(cpu, sigp_emergency_signal) == sigp_busy)
- udelay(10);
- }
-}
-
#ifndef CONFIG_64BIT
/*
* this function sends a 'purge tlb' signal to another CPU.
@@ -807,6 +781,5 @@ EXPORT_SYMBOL(cpu_possible_map);
EXPORT_SYMBOL(lowcore_ptr);
EXPORT_SYMBOL(smp_ctl_set_bit);
EXPORT_SYMBOL(smp_ctl_clear_bit);
-EXPORT_SYMBOL(smp_call_function);
EXPORT_SYMBOL(smp_get_cpu);
EXPORT_SYMBOL(smp_put_cpu);
--
blue skies, IBM Deutschland Entwicklung GmbH
Martin Vorsitzender des Aufsichtsrats: Johann Weihen
Geschäftsführung: Herbert Kircher
Martin Schwidefsky Sitz der Gesellschaft: Böblingen
Linux on zSeries Registergericht: Amtsgericht Stuttgart,
Development HRB 243294
"Reality continues to ruin my life." - Calvin.
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