[PATCH 9/11] parisc: convert to generic helpers for IPI function calls

Jens Axboe
2008-04-22T08:01:14Z

This converts mips to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single(). Not tested,
not even compiled.

Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
arch/parisc/Kconfig | 5 ++
arch/parisc/kernel/smp.c | 134 +++++++--------------------------------------
2 files changed, 26 insertions(+), 113 deletions(-)

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index bc7a19d..73ab474 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -72,6 +72,11 @@ config GENERIC_HARDIRQS
config GENERIC_IRQ_PROBE
def_bool y

+config GENERIC_SMP_HELPERS
+ bool
+ depends on SMP
+ default y
+
config IRQ_PER_CPU
bool
default y
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 85fc775..126105c 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -84,19 +84,11 @@ EXPORT_SYMBOL(cpu_possible_map);

DEFINE_PER_CPU(spinlock_t, ipi_lock) = SPIN_LOCK_UNLOCKED;

-struct smp_call_struct {
- void (*func) (void *info);
- void *info;
- long wait;
- atomic_t unstarted_count;
- atomic_t unfinished_count;
-};
-static volatile struct smp_call_struct *smp_call_function_data;
-
enum ipi_message_type {
IPI_NOP=0,
IPI_RESCHEDULE=1,
IPI_CALL_FUNC,
+ IPI_CALL_FUNC_SINGLE,
IPI_CPU_START,
IPI_CPU_STOP,
IPI_CPU_TEST
@@ -187,33 +179,12 @@ ipi_interrupt(int irq, void *dev_id)

case IPI_CALL_FUNC:
smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC\n", this_cpu);
- {
- volatile struct smp_call_struct *data;
- void (*func)(void *info);
- void *info;
- int wait;
-
- data = smp_call_function_data;
- func = data->func;
- info = data->info;
- wait = data->wait;
-
- mb();
- atomic_dec ((atomic_t *)&data->unstarted_count);
-
- /* At this point, *data can't
- * be relied upon.
- */
-
- (*func)(info);
-
- /* Notify the sending CPU that the
- * task is done.
- */
- mb();
- if (wait)
- atomic_dec ((atomic_t *)&data->unfinished_count);
- }
+ generic_smp_call_function_interrupt();
+ break;
+
+ case IPI_CALL_FUNC_SINGLE:
+ smp_debug(100, KERN_DEBUG "CPU%d IPI_CALL_FUNC_SINGLE\n", this_cpu);
+ generic_smp_call_function_single_interrupt();
break;

case IPI_CPU_START:
@@ -256,6 +227,14 @@ ipi_send(int cpu, enum ipi_message_type op)
spin_unlock_irqrestore(lock, flags);
}

+static void
+send_IPI_mask(cpumask_t mask, enum ipi_message_type op)
+{
+ int cpu;
+
+ for_each_cpu_mask(cpu, mask)
+ ipi_send(cpu, op);
+}

static inline void
send_IPI_single(int dest_cpu, enum ipi_message_type op)
@@ -295,86 +274,15 @@ smp_send_all_nop(void)
send_IPI_allbutself(IPI_NOP);
}

-
-/**
- * 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.
- * <retry> If true, keep retrying until ready.
- * <wait> If true, wait 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 have executed.
- */
-
-int
-smp_call_function (void (*func) (void *info), void *info, int retry, int wait)
+void arch_send_call_function_ipi(cpumask_t mask)
{
- struct smp_call_struct data;
- unsigned long timeout;
- static DEFINE_SPINLOCK(lock);
- int retries = 0;
-
- if (num_online_cpus() < 2)
- return 0;
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- /* can also deadlock if IPIs are disabled */
- WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0);
-
-
- data.func = func;
- data.info = info;
- data.wait = wait;
- atomic_set(&data.unstarted_count, num_online_cpus() - 1);
- atomic_set(&data.unfinished_count, num_online_cpus() - 1);
-
- if (retry) {
- spin_lock (&lock);
- while (smp_call_function_data != 0)
- barrier();
- }
- else {
- spin_lock (&lock);
- if (smp_call_function_data) {
- spin_unlock (&lock);
- return -EBUSY;
- }
- }
-
- smp_call_function_data = &data;
- spin_unlock (&lock);
-
- /* Send a message to all other CPUs and wait for them to respond */
- send_IPI_allbutself(IPI_CALL_FUNC);
-
- retry:
- /* Wait for response */
- timeout = jiffies + HZ;
- while ( (atomic_read (&data.unstarted_count) > 0) &&
- time_before (jiffies, timeout) )
- barrier ();
-
- if (atomic_read (&data.unstarted_count) > 0) {
- printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n",
- smp_processor_id(), ++retries);
- goto retry;
- }
- /* We either got one or timed out. Release the lock */
-
- mb();
- smp_call_function_data = NULL;
-
- while (wait && atomic_read (&data.unfinished_count) > 0)
- barrier ();
-
- return 0;
+ send_IPI_mask(mask, IPI_CALL_FUNC);
}

-EXPORT_SYMBOL(smp_call_function);
+void arch_send_call_function_single_ipi(int cpu)
+{
+ send_IPI_single(cpu, IPI_CALL_FUNC_SINGLE);
+}

/*
* Flush all other CPU's tlb and then mine. Do this with on_each_cpu()
--
1.5.5.49.gf43e2