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Date: Thu, 29 May 2008 10:58:22 +0200
From: Jens Axboe <jens.axboe@...cle.com>
To: linux-kernel@...r.kernel.org
Cc: peterz@...radead.org, npiggin@...e.de, linux-arch@...r.kernel.org,
jeremy@...p.org, mingo@...e.hu, paulmck@...ux.vnet.ibm.com,
Jens Axboe <jens.axboe@...cle.com>,
Ralf Baechle <ralf@...ux-mips.org>
Subject: [PATCH 8/10] mips: convert to generic helpers for IPI function calls
This converts mips to use the new helpers for smp_call_function() and
friends, and adds support for smp_call_function_single(). Not tested,
but it compiles.
mips shares the same IPI for smp_call_function() and
smp_call_function_single(), since not all hardware has enough available
IPIs available to support seperate setups.
Cc: Ralf Baechle <ralf@...ux-mips.org>
Signed-off-by: Jens Axboe <jens.axboe@...cle.com>
---
arch/mips/Kconfig | 1 +
arch/mips/kernel/smp.c | 139 ++++-------------------------------------------
arch/mips/kernel/smtc.c | 1 -
include/asm-mips/smp.h | 10 ----
4 files changed, 12 insertions(+), 139 deletions(-)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e5a7c5d..ea70d5a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1763,6 +1763,7 @@ config SMP
bool "Multi-Processing support"
depends on SYS_SUPPORTS_SMP
select IRQ_PER_CPU
+ select USE_GENERIC_SMP_HELPERS
help
This enables support for systems with more than one CPU. If you have
a system with only one CPU, like most personal computers, say N. If
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 63370cd..c75b26c 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -131,145 +131,28 @@ asmlinkage __cpuinit void start_secondary(void)
cpu_idle();
}
-DEFINE_SPINLOCK(smp_call_lock);
-
-struct call_data_struct *call_data;
-
-/*
- * Run a function on all other CPUs.
- *
- * <mask> cpuset_t of all processors to run the function on.
- * <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 are or have executed.
- *
- * You must not call this function with disabled interrupts or from a
- * hardware interrupt handler or from a bottom half handler:
- *
- * CPU A CPU B
- * Disable interrupts
- * smp_call_function()
- * Take call_lock
- * Send IPIs
- * Wait for all cpus to acknowledge IPI
- * CPU A has not responded, spin waiting
- * for cpu A to respond, holding call_lock
- * smp_call_function()
- * Spin waiting for call_lock
- * Deadlock Deadlock
- */
-int smp_call_function_mask(cpumask_t mask, void (*func) (void *info),
- void *info, int retry, int wait)
+void arch_send_call_function_ipi(cpumask_t mask)
{
- struct call_data_struct data;
- int cpu = smp_processor_id();
- int cpus;
-
- /*
- * Can die spectacularly if this CPU isn't yet marked online
- */
- BUG_ON(!cpu_online(cpu));
-
- cpu_clear(cpu, mask);
- cpus = cpus_weight(mask);
- if (!cpus)
- return 0;
-
- /* Can deadlock when called with interrupts disabled */
- WARN_ON(irqs_disabled());
-
- data.func = func;
- data.info = info;
- atomic_set(&data.started, 0);
- data.wait = wait;
- if (wait)
- atomic_set(&data.finished, 0);
-
- spin_lock(&smp_call_lock);
- call_data = &data;
- smp_mb();
-
- /* Send a message to all other CPUs and wait for them to respond */
mp_ops->send_ipi_mask(mask, SMP_CALL_FUNCTION);
-
- /* Wait for response */
- /* FIXME: lock-up detection, backtrace on lock-up */
- while (atomic_read(&data.started) != cpus)
- barrier();
-
- if (wait)
- while (atomic_read(&data.finished) != cpus)
- barrier();
- call_data = NULL;
- spin_unlock(&smp_call_lock);
-
- return 0;
}
-int smp_call_function(void (*func) (void *info), void *info, int retry,
- int wait)
+/*
+ * We reuse the same vector for the single IPI
+ */
+void arch_send_call_function_single_ipi(int cpu)
{
- return smp_call_function_mask(cpu_online_map, func, info, retry, wait);
+ mp_ops->send_ipi_mask(cpumask_of_cpu(cpu), SMP_CALL_FUNCTION);
}
+/*
+ * Call into both interrupt handlers, as we share the IPI for them
+ */
void smp_call_function_interrupt(void)
{
- void (*func) (void *info) = call_data->func;
- void *info = call_data->info;
- int wait = call_data->wait;
-
- /*
- * Notify initiating CPU that I've grabbed the data and am
- * about to execute the function.
- */
- smp_mb();
- atomic_inc(&call_data->started);
-
- /*
- * At this point the info structure may be out of scope unless wait==1.
- */
irq_enter();
- (*func)(info);
+ generic_smp_call_function_single_interrupt();
+ generic_smp_call_function_interrupt();
irq_exit();
-
- if (wait) {
- smp_mb();
- atomic_inc(&call_data->finished);
- }
-}
-
-int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
- int retry, int wait)
-{
- int ret, me;
-
- /*
- * Can die spectacularly if this CPU isn't yet marked online
- */
- if (!cpu_online(cpu))
- return 0;
-
- me = get_cpu();
- BUG_ON(!cpu_online(me));
-
- if (cpu == me) {
- local_irq_disable();
- func(info);
- local_irq_enable();
- put_cpu();
- return 0;
- }
-
- ret = smp_call_function_mask(cpumask_of_cpu(cpu), func, info, retry,
- wait);
-
- put_cpu();
- return 0;
}
static void stop_this_cpu(void *dummy)
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c
index 3e86318..a516286 100644
--- a/arch/mips/kernel/smtc.c
+++ b/arch/mips/kernel/smtc.c
@@ -877,7 +877,6 @@ static void ipi_resched_interrupt(void)
/* Return from interrupt should be enough to cause scheduler check */
}
-
static void ipi_call_interrupt(void)
{
/* Invoke generic function invocation code in smp.c */
diff --git a/include/asm-mips/smp.h b/include/asm-mips/smp.h
index 84fef1a..5222587 100644
--- a/include/asm-mips/smp.h
+++ b/include/asm-mips/smp.h
@@ -35,16 +35,6 @@ extern int __cpu_logical_map[NR_CPUS];
#define NO_PROC_ID (-1)
-struct call_data_struct {
- void (*func)(void *);
- void *info;
- atomic_t started;
- atomic_t finished;
- int wait;
-};
-
-extern struct call_data_struct *call_data;
-
#define SMP_RESCHEDULE_YOURSELF 0x1 /* XXX braindead */
#define SMP_CALL_FUNCTION 0x2
--
1.5.6.rc0.40.gd683
--
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