[PATCH 3/11] powerpc: convert to generic helpers for IPI function calls

Jens Axboe
2008-04-22T07:58:14Z

This converts ppc to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single().

Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
arch/powerpc/Kconfig | 5 +
arch/powerpc/kernel/smp.c | 220 ++-----------------------------
arch/powerpc/platforms/cell/interrupt.c | 1 +
arch/powerpc/platforms/ps3/smp.c | 7 +-
arch/powerpc/platforms/pseries/xics.c | 6 +-
arch/powerpc/sysdev/mpic.c | 2 +-
include/asm-powerpc/smp.h | 5 +-
7 files changed, 27 insertions(+), 219 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4bb2e93..ad394d4 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -42,6 +42,11 @@ config GENERIC_HARDIRQS
bool
default y

+config GENERIC_SMP_HELPERS
+ bool
+ depends on SMP
+ default y
+
config HAVE_SETUP_PER_CPU_AREA
def_bool PPC64

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index be35ffa..facd49d 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -72,12 +72,8 @@ struct smp_ops_t *smp_ops;

static volatile unsigned int cpu_callin_map[NR_CPUS];

-void smp_call_function_interrupt(void);
-
int smt_enabled_at_boot = 1;

-static int ipi_fail_ok;
-
static void (*crash_ipi_function_ptr)(struct pt_regs *) = NULL;

#ifdef CONFIG_PPC64
@@ -99,12 +95,15 @@ void smp_message_recv(int msg)
{
switch(msg) {
case PPC_MSG_CALL_FUNCTION:
- smp_call_function_interrupt();
+ generic_smp_call_function_interrupt();
break;
case PPC_MSG_RESCHEDULE:
/* XXX Do we have to do this? */
set_need_resched();
break;
+ case PPC_MSG_CALL_FUNC_SINGLE:
+ generic_smp_call_function_single_interrupt();
+ break;
case PPC_MSG_DEBUGGER_BREAK:
if (crash_ipi_function_ptr) {
crash_ipi_function_ptr(get_irq_regs());
@@ -154,215 +153,22 @@ static void stop_this_cpu(void *dummy)
;
}

-/*
- * Structure and data for smp_call_function(). This is designed to minimise
- * static memory requirements. It also looks cleaner.
- * Stolen from the i386 version.
- */
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);
-
-static struct call_data_struct {
- void (*func) (void *info);
- void *info;
- atomic_t started;
- atomic_t finished;
- int wait;
-} *call_data;
-
-/* delay of at least 8 seconds */
-#define SMP_CALL_TIMEOUT 8
-
-/*
- * These functions send a 'generic call function' IPI to other online
- * CPUS in the system.
- *
- * [SUMMARY] Run a function on 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.
- * is a cpu map of the cpus to send IPI to.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler.
- */
-static int __smp_call_function_map(void (*func) (void *info), void *info,
- int nonatomic, int wait, cpumask_t map)
-{
- struct call_data_struct data;
- int ret = -1, num_cpus;
- int cpu;
- u64 timeout;
-
- if (unlikely(smp_ops == NULL))
- return ret;
-
- data.func = func;
- data.info = info;
- atomic_set(&data.started, 0);
- data.wait = wait;
- if (wait)
- atomic_set(&data.finished, 0);
-
- /* remove 'self' from the map */
- if (cpu_isset(smp_processor_id(), map))
- cpu_clear(smp_processor_id(), map);
-
- /* sanity check the map, remove any non-online processors. */
- cpus_and(map, map, cpu_online_map);
-
- num_cpus = cpus_weight(map);
- if (!num_cpus)
- goto done;
-
- call_data = &data;
- smp_wmb();
- /* Send a message to all CPUs in the map */
- for_each_cpu_mask(cpu, map)
- smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
-
- timeout = get_tb() + (u64) SMP_CALL_TIMEOUT * tb_ticks_per_sec;
-
- /* Wait for indication that they have received the message */
- while (atomic_read(&data.started) != num_cpus) {
- HMT_low();
- if (get_tb() >= timeout) {
- printk("smp_call_function on cpu %d: other cpus not "
- "responding (%d)\n", smp_processor_id(),
- atomic_read(&data.started));
- if (!ipi_fail_ok)
- debugger(NULL);
- goto out;
- }
- }
-
- /* optionally wait for the CPUs to complete */
- if (wait) {
- while (atomic_read(&data.finished) != num_cpus) {
- HMT_low();
- if (get_tb() >= timeout) {
- printk("smp_call_function on cpu %d: other "
- "cpus not finishing (%d/%d)\n",
- smp_processor_id(),
- atomic_read(&data.finished),
- atomic_read(&data.started));
- debugger(NULL);
- goto out;
- }
- }
- }
-
- done:
- ret = 0;
-
- out:
- call_data = NULL;
- HMT_medium();
- return ret;
-}
-
-static int __smp_call_function(void (*func)(void *info), void *info,
- int nonatomic, int wait)
+void arch_send_call_function_single_ipi(int cpu)
{
- int ret;
- spin_lock(&call_lock);
- ret =__smp_call_function_map(func, info, nonatomic, wait,
- cpu_online_map);
- spin_unlock(&call_lock);
- return ret;
-}
-
-int smp_call_function(void (*func) (void *info), void *info, int nonatomic,
- int wait)
-{
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- return __smp_call_function(func, info, nonatomic, wait);
+ smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
}
-EXPORT_SYMBOL(smp_call_function);

-int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
- int nonatomic, int wait)
+void arch_send_call_function_ipi(cpumask_t mask)
{
- cpumask_t map = CPU_MASK_NONE;
- int ret = 0;
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- if (!cpu_online(cpu))
- return -EINVAL;
+ unsigned int cpu;

- cpu_set(cpu, map);
- if (cpu != get_cpu()) {
- spin_lock(&call_lock);
- ret = __smp_call_function_map(func, info, nonatomic, wait, map);
- spin_unlock(&call_lock);
- } else {
- local_irq_disable();
- func(info);
- local_irq_enable();
- }
- put_cpu();
- return ret;
+ for_each_cpu_mask(cpu, mask)
+ smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
}
-EXPORT_SYMBOL(smp_call_function_single);

void smp_send_stop(void)
{
- int nolock;
-
- /* It's OK to fail sending the IPI, since the alternative is to
- * be stuck forever waiting on the other CPU to take the interrupt.
- *
- * It's better to at least continue and go through reboot, since this
- * function is usually called at panic or reboot time in the first
- * place.
- */
- ipi_fail_ok = 1;
-
- /* Don't deadlock in case we got called through panic */
- nolock = !spin_trylock(&call_lock);
- __smp_call_function_map(stop_this_cpu, NULL, 1, 0, cpu_online_map);
- if (!nolock)
- spin_unlock(&call_lock);
-}
-
-void smp_call_function_interrupt(void)
-{
- void (*func) (void *info);
- void *info;
- int wait;
-
- /* call_data will be NULL if the sender timed out while
- * waiting on us to receive the call.
- */
- if (!call_data)
- return;
-
- func = call_data->func;
- info = call_data->info;
- wait = call_data->wait;
-
- if (!wait)
- smp_mb__before_atomic_inc();
-
- /*
- * Notify initiating CPU that I've grabbed the data and am
- * about to execute the function
- */
- atomic_inc(&call_data->started);
- /*
- * At this point the info structure may be out of scope unless wait==1
- */
- (*func)(info);
- if (wait) {
- smp_mb__before_atomic_inc();
- atomic_inc(&call_data->finished);
- }
+ smp_call_function(stop_this_cpu, NULL, 0, 0);
}

extern struct gettimeofday_struct do_gtod;
@@ -594,9 +400,9 @@ int __devinit start_secondary(void *unused)

secondary_cpu_time_init();

- spin_lock(&call_lock);
+ spin_lock(&call_function_lock);
cpu_set(cpu, cpu_online_map);
- spin_unlock(&call_lock);
+ spin_unlock(&call_function_lock);

local_irq_enable();

diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 04f74f9..bc91ec5 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -217,6 +217,7 @@ void iic_request_IPIs(void)
{
iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
+ iic_request_ipi(PPC_MSG_CALL_FUNC_SINGLE, "IPI-call-single");
#ifdef CONFIG_DEBUGGER
iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
#endif /* CONFIG_DEBUGGER */
diff --git a/arch/powerpc/platforms/ps3/smp.c b/arch/powerpc/platforms/ps3/smp.c
index f0b12f2..a0927a3 100644
--- a/arch/powerpc/platforms/ps3/smp.c
+++ b/arch/powerpc/platforms/ps3/smp.c
@@ -105,9 +105,10 @@ static void __init ps3_smp_setup_cpu(int cpu)
* to index needs to be setup.
*/

- BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION != 0);
- BUILD_BUG_ON(PPC_MSG_RESCHEDULE != 1);
- BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK != 3);
+ BUILD_BUG_ON(PPC_MSG_CALL_FUNCTION != 0);
+ BUILD_BUG_ON(PPC_MSG_RESCHEDULE != 1);
+ BUILD_BUG_ON(PPC_MSG_CALL_FUNC_SINGLE != 2);
+ BUILD_BUG_ON(PPC_MSG_DEBUGGER_BREAK != 3);

for (i = 0; i < MSG_COUNT; i++) {
result = ps3_event_receive_port_setup(cpu, &virqs[i]);
diff --git a/arch/powerpc/platforms/pseries/xics.c b/arch/powerpc/platforms/pseries/xics.c
index 43df53c..b343245 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -384,13 +384,11 @@ static irqreturn_t xics_ipi_dispatch(int cpu)
mb();
smp_message_recv(PPC_MSG_RESCHEDULE);
}
-#if 0
- if (test_and_clear_bit(PPC_MSG_MIGRATE_TASK,
+ if (test_and_clear_bit(PPC_MSG_CALL_FUNC_SINGLE,
&xics_ipi_message[cpu].value)) {
mb();
- smp_message_recv(PPC_MSG_MIGRATE_TASK);
+ smp_message_recv(PPC_MSG_CALL_FUNC_SINGLE);
}
-#endif
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
if (test_and_clear_bit(PPC_MSG_DEBUGGER_BREAK,
&xics_ipi_message[cpu].value)) {
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 8619f2a..bdc7b13 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1508,7 +1508,7 @@ void mpic_request_ipis(void)
static char *ipi_names[] = {
"IPI0 (call function)",
"IPI1 (reschedule)",
- "IPI2 (unused)",
+ "IPI2 (call function single)",
"IPI3 (debugger break)",
};
BUG_ON(mpic == NULL);
diff --git a/include/asm-powerpc/smp.h b/include/asm-powerpc/smp.h
index 505f35b..78382f6 100644
--- a/include/asm-powerpc/smp.h
+++ b/include/asm-powerpc/smp.h
@@ -67,10 +67,7 @@ DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
* in /proc/interrupts will be wrong!!! --Troy */
#define PPC_MSG_CALL_FUNCTION 0
#define PPC_MSG_RESCHEDULE 1
-/* This is unused now */
-#if 0
-#define PPC_MSG_MIGRATE_TASK 2
-#endif
+#define PPC_MSG_CALL_FUNC_SINGLE 2
#define PPC_MSG_DEBUGGER_BREAK 3

void smp_init_iSeries(void);
--
1.5.5.49.gf43e2