powerpc: convert to generic helpers for IPI function calls

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

ppc loses the timeout functionality of smp_call_function_mask() with
this change, as the generic code does not provide that.

Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

7 files changed, 33 insertions, 226 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3934e265940..852d40c2963 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -110,6 +110,7 @@ config PPC
         select HAVE_KPROBES
         select HAVE_KRETPROBES
         select HAVE_LMB
+        select USE_GENERIC_SMP_HELPERS if SMP
 
 config EARLY_PRINTK
         bool
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index 1457aa0a08f..37a5ab410dc 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());
@@ -128,6 +127,19 @@ void smp_send_reschedule(int cpu)
                 smp_ops->message_pass(cpu, PPC_MSG_RESCHEDULE);
 }
 
+void arch_send_call_function_single_ipi(int cpu)
+{
+        smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNC_SINGLE);
+}
+
+void arch_send_call_function_ipi(cpumask_t mask)
+{
+        unsigned int cpu;
+
+        for_each_cpu_mask(cpu, mask)
+                smp_ops->message_pass(cpu, PPC_MSG_CALL_FUNCTION);
+}
+
 #ifdef CONFIG_DEBUGGER
 void smp_send_debugger_break(int cpu)
 {
@@ -154,215 +166,9 @@ 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.
- * <map> 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)
-{
-        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);
-}
-EXPORT_SYMBOL(smp_call_function);
-
-int smp_call_function_single(int cpu, void (*func) (void *info), void *info,
-                             int nonatomic, int wait)
-{
-        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;
-
-        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;
-}
-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;
@@ -596,9 +402,9 @@ int __devinit start_secondary(void *unused)
 
         secondary_cpu_time_init();
 
-        spin_lock(&call_lock);
+        ipi_call_lock();
         cpu_set(cpu, cpu_online_map);
-        spin_unlock(&call_lock);
+        ipi_call_unlock();
 
         local_irq_enable();
 
diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c
index 5bf7df14602..2d5bb22d6c0 100644
--- a/arch/powerpc/platforms/cell/interrupt.c
+++ b/arch/powerpc/platforms/cell/interrupt.c
@@ -218,6 +218,7 @@ 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 f0b12f21236..a0927a3bacb 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 ebebc28fe89..0fc830f576f 100644
--- a/arch/powerpc/platforms/pseries/xics.c
+++ b/arch/powerpc/platforms/pseries/xics.c
@@ -383,13 +383,11 @@ 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 7680001676a..6c90c95b454 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1494,7 +1494,7 @@ 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 505f35bacaa..c663a1fa77c 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);
@@ -117,6 +114,9 @@ extern void smp_generic_take_timebase(void);
 
 extern struct smp_ops_t *smp_ops;
 
+extern void arch_send_call_function_single_ipi(int cpu);
+extern void arch_send_call_function_ipi(cpumask_t mask);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */