arm: convert to generic helpers for IPI function calls

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

Fixups and testing done by Catalin Marinas <catalin.marinas@arm.com>

Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

3 files changed, 19 insertions, 142 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b786e68914d4..c72dae633f60 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -650,6 +650,7 @@ source "kernel/time/Kconfig"
 config SMP
         bool "Symmetric Multi-Processing (EXPERIMENTAL)"
         depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP)
+        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/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index eefae1de334c..6344466b2113 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -68,20 +68,10 @@ enum ipi_msg_type {
         IPI_TIMER,
         IPI_RESCHEDULE,
         IPI_CALL_FUNC,
+        IPI_CALL_FUNC_SINGLE,
         IPI_CPU_STOP,
 };
 
-struct smp_call_struct {
-        void (*func)(void *info);
-        void *info;
-        int wait;
-        cpumask_t pending;
-        cpumask_t unfinished;
-};
-
-static struct smp_call_struct * volatile smp_call_function_data;
-static DEFINE_SPINLOCK(smp_call_function_lock);
-
 int __cpuinit __cpu_up(unsigned int cpu)
 {
         struct cpuinfo_arm *ci = &per_cpu(cpu_data, cpu);
@@ -366,114 +356,15 @@ static void send_ipi_message(cpumask_t callmap, enum ipi_msg_type msg)
         local_irq_restore(flags);
 }
 
-/*
- * You must not call this function with disabled interrupts, from a
- * hardware interrupt handler, nor from a bottom half handler.
- */
-static int smp_call_function_on_cpu(void (*func)(void *info), void *info,
-                                    int retry, int wait, cpumask_t callmap)
-{
-        struct smp_call_struct data;
-        unsigned long timeout;
-        int ret = 0;
-
-        data.func = func;
-        data.info = info;
-        data.wait = wait;
-
-        cpu_clear(smp_processor_id(), callmap);
-        if (cpus_empty(callmap))
-                goto out;
-
-        data.pending = callmap;
-        if (wait)
-                data.unfinished = callmap;
-
-        /*
-         * try to get the mutex on smp_call_function_data
-         */
-        spin_lock(&smp_call_function_lock);
-        smp_call_function_data = &data;
-
-        send_ipi_message(callmap, IPI_CALL_FUNC);
-
-        timeout = jiffies + HZ;
-        while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
-                barrier();
-
-        /*
-         * did we time out?
-         */
-        if (!cpus_empty(data.pending)) {
-                /*
-                 * this may be causing our panic - report it
-                 */
-                printk(KERN_CRIT
-                       "CPU%u: smp_call_function timeout for %p(%p)\n"
-                       "      callmap %lx pending %lx, %swait\n",
-                       smp_processor_id(), func, info, *cpus_addr(callmap),
-                       *cpus_addr(data.pending), wait ? "" : "no ");
-
-                /*
-                 * TRACE
-                 */
-                timeout = jiffies + (5 * HZ);
-                while (!cpus_empty(data.pending) && time_before(jiffies, timeout))
-                        barrier();
-
-                if (cpus_empty(data.pending))
-                        printk(KERN_CRIT "     RESOLVED\n");
-                else
-                        printk(KERN_CRIT "     STILL STUCK\n");
-        }
-
-        /*
-         * whatever happened, we're done with the data, so release it
-         */
-        smp_call_function_data = NULL;
-        spin_unlock(&smp_call_function_lock);
-
-        if (!cpus_empty(data.pending)) {
-                ret = -ETIMEDOUT;
-                goto out;
-        }
-
-        if (wait)
-                while (!cpus_empty(data.unfinished))
-                        barrier();
- out:
-
-        return 0;
-}
-
-int smp_call_function(void (*func)(void *info), void *info, int retry,
-                      int wait)
+void arch_send_call_function_ipi(cpumask_t mask)
 {
-        return smp_call_function_on_cpu(func, info, retry, wait,
-                                        cpu_online_map);
+        send_ipi_message(mask, IPI_CALL_FUNC);
 }
-EXPORT_SYMBOL_GPL(smp_call_function);
 
-int smp_call_function_single(int cpu, void (*func)(void *info), void *info,
-                             int retry, int wait)
+void arch_send_call_function_single_ipi(int cpu)
 {
-        /* prevent preemption and reschedule on another processor */
-        int current_cpu = get_cpu();
-        int ret = 0;
-
-        if (cpu == current_cpu) {
-                local_irq_disable();
-                func(info);
-                local_irq_enable();
-        } else
-                ret = smp_call_function_on_cpu(func, info, retry, wait,
-                                               cpumask_of_cpu(cpu));
-
-        put_cpu();
-
-        return ret;
+        send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE);
 }
-EXPORT_SYMBOL_GPL(smp_call_function_single);
 
 void show_ipi_list(struct seq_file *p)
 {
@@ -521,27 +412,6 @@ asmlinkage void __exception do_local_timer(struct pt_regs *regs)
 }
 #endif
 
-/*
- * ipi_call_function - handle IPI from smp_call_function()
- *
- * Note that we copy data out of the cross-call structure and then
- * let the caller know that we're here and have done with their data
- */
-static void ipi_call_function(unsigned int cpu)
-{
-        struct smp_call_struct *data = smp_call_function_data;
-        void (*func)(void *info) = data->func;
-        void *info = data->info;
-        int wait = data->wait;
-
-        cpu_clear(cpu, data->pending);
-
-        func(info);
-
-        if (wait)
-                cpu_clear(cpu, data->unfinished);
-}
-
 static DEFINE_SPINLOCK(stop_lock);
 
 /*
@@ -611,7 +481,11 @@ asmlinkage void __exception do_IPI(struct pt_regs *regs)
                                 break;
 
                         case IPI_CALL_FUNC:
-                                ipi_call_function(cpu);
+                                generic_smp_call_function_interrupt();
+                                break;
+
+                        case IPI_CALL_FUNC_SINGLE:
+                                generic_smp_call_function_single_interrupt();
                                 break;
 
                         case IPI_CPU_STOP:
@@ -662,14 +536,13 @@ int setup_profiling_timer(unsigned int multiplier)
 }
 
 static int
-on_each_cpu_mask(void (*func)(void *), void *info, int retry, int wait,
-                 cpumask_t mask)
+on_each_cpu_mask(void (*func)(void *), void *info, int wait, cpumask_t mask)
 {
         int ret = 0;
 
         preempt_disable();
 
-        ret = smp_call_function_on_cpu(func, info, retry, wait, mask);
+        ret = smp_call_function_mask(mask, func, info, wait);
         if (cpu_isset(smp_processor_id(), mask))
                 func(info);
 
@@ -738,7 +611,7 @@ void flush_tlb_mm(struct mm_struct *mm)
 {
         cpumask_t mask = mm->cpu_vm_mask;
 
-        on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, 1, mask);
+        on_each_cpu_mask(ipi_flush_tlb_mm, mm, 1, mask);
 }
 
 void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
@@ -749,7 +622,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long uaddr)
         ta.ta_vma = vma;
         ta.ta_start = uaddr;
 
-        on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, 1, mask);
+        on_each_cpu_mask(ipi_flush_tlb_page, &ta, 1, mask);
 }
 
 void flush_tlb_kernel_page(unsigned long kaddr)
@@ -771,7 +644,7 @@ void flush_tlb_range(struct vm_area_struct *vma,
         ta.ta_start = start;
         ta.ta_end = end;
 
-        on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, 1, mask);
+        on_each_cpu_mask(ipi_flush_tlb_range, &ta, 1, mask);
 }
 
 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
diff --git a/include/asm-arm/smp.h b/include/asm-arm/smp.h
index af99636db400..7fffa2404b8e 100644
--- a/include/asm-arm/smp.h
+++ b/include/asm-arm/smp.h
@@ -101,6 +101,9 @@ extern void platform_cpu_die(unsigned int cpu);
 extern int platform_cpu_kill(unsigned int cpu);
 extern void platform_cpu_enable(unsigned int cpu);
 
+extern void arch_send_call_function_single_ipi(int cpu);
+extern void arch_send_call_function_ipi(cpumask_t mask);
+
 /*
  * Local timer interrupt handling function (can be IPI'ed).
  */