From c524a1d8914408fd57241d9542fa2d402f004a33 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 10 Jun 2008 20:47:29 +0200 Subject: [PATCH] alpha: convert to generic helpers for IPI function calls This converts alpha to use the new helpers for smp_call_function() and friends, and adds support for smp_call_function_single(). Signed-off-by: Jens Axboe --- arch/alpha/Kconfig | 1 + arch/alpha/kernel/core_marvel.c | 6 +- arch/alpha/kernel/smp.c | 170 ++------------------------------ include/asm-alpha/smp.h | 3 +- 4 files changed, 16 insertions(+), 164 deletions(-) diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 729cdbdf8036..dbe8c280fea9 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -528,6 +528,7 @@ config ARCH_MAY_HAVE_PC_FDC config SMP bool "Symmetric multi-processing support" depends on ALPHA_SABLE || ALPHA_LYNX || ALPHA_RAWHIDE || ALPHA_DP264 || ALPHA_WILDFIRE || ALPHA_TITAN || ALPHA_GENERIC || ALPHA_SHARK || ALPHA_MARVEL + 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/alpha/kernel/core_marvel.c b/arch/alpha/kernel/core_marvel.c index b04f1feb1dda..ced4aae8b804 100644 --- a/arch/alpha/kernel/core_marvel.c +++ b/arch/alpha/kernel/core_marvel.c @@ -660,9 +660,9 @@ __marvel_rtc_io(u8 b, unsigned long addr, int write) #ifdef CONFIG_SMP if (smp_processor_id() != boot_cpuid) - smp_call_function_on_cpu(__marvel_access_rtc, - &rtc_access, 1, 1, - cpumask_of_cpu(boot_cpuid)); + smp_call_function_single(boot_cpuid, + __marvel_access_rtc, + &rtc_access, 1, 1); else __marvel_access_rtc(&rtc_access); #else diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c index 2525692db0ab..95c905be9154 100644 --- a/arch/alpha/kernel/smp.c +++ b/arch/alpha/kernel/smp.c @@ -62,6 +62,7 @@ static struct { enum ipi_message_type { IPI_RESCHEDULE, IPI_CALL_FUNC, + IPI_CALL_FUNC_SINGLE, IPI_CPU_STOP, }; @@ -558,51 +559,6 @@ send_ipi_message(cpumask_t to_whom, enum ipi_message_type operation) wripir(i); } -/* Structure and data for smp_call_function. This is designed to - minimize static memory requirements. Plus it looks cleaner. */ - -struct smp_call_struct { - void (*func) (void *info); - void *info; - long wait; - atomic_t unstarted_count; - atomic_t unfinished_count; -}; - -static struct smp_call_struct *smp_call_function_data; - -/* Atomicly drop data into a shared pointer. The pointer is free if - it is initially locked. If retry, spin until free. */ - -static int -pointer_lock (void *lock, void *data, int retry) -{ - void *old, *tmp; - - mb(); - again: - /* Compare and swap with zero. */ - asm volatile ( - "1: ldq_l %0,%1\n" - " mov %3,%2\n" - " bne %0,2f\n" - " stq_c %2,%1\n" - " beq %2,1b\n" - "2:" - : "=&r"(old), "=m"(*(void **)lock), "=&r"(tmp) - : "r"(data) - : "memory"); - - if (old == 0) - return 0; - if (! retry) - return -EBUSY; - - while (*(void **)lock) - barrier(); - goto again; -} - void handle_ipi(struct pt_regs *regs) { @@ -632,31 +588,12 @@ handle_ipi(struct pt_regs *regs) break; case IPI_CALL_FUNC: - { - 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; - - /* Notify the sending CPU that the data has been - received, and execution is about to begin. */ - mb(); - atomic_dec (&data->unstarted_count); - - /* At this point the structure may be gone unless - wait is true. */ - (*func)(info); - - /* Notify the sending CPU that the task is done. */ - mb(); - if (wait) atomic_dec (&data->unfinished_count); + generic_smp_call_function_interrupt(); + break; + + case IPI_CALL_FUNC_SINGLE: + generic_smp_call_function_single_interrupt(); break; - } case IPI_CPU_STOP: halt(); @@ -700,102 +637,15 @@ smp_send_stop(void) send_ipi_message(to_whom, IPI_CPU_STOP); } -/* - * Run a function on all other CPUs. - * The function to run. This must be fast and non-blocking. - * An arbitrary pointer to pass to the function. - * If true, keep retrying until ready. - * 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 - * 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. - */ - -int -smp_call_function_on_cpu (void (*func) (void *info), void *info, int retry, - int wait, cpumask_t to_whom) +void arch_send_call_function_ipi(cpumask_t mask) { - struct smp_call_struct data; - unsigned long timeout; - int num_cpus_to_call; - - /* Can deadlock when called with interrupts disabled */ - WARN_ON(irqs_disabled()); - - data.func = func; - data.info = info; - data.wait = wait; - - cpu_clear(smp_processor_id(), to_whom); - num_cpus_to_call = cpus_weight(to_whom); - - atomic_set(&data.unstarted_count, num_cpus_to_call); - atomic_set(&data.unfinished_count, num_cpus_to_call); - - /* Acquire the smp_call_function_data mutex. */ - if (pointer_lock(&smp_call_function_data, &data, retry)) - return -EBUSY; - - /* Send a message to the requested CPUs. */ - send_ipi_message(to_whom, IPI_CALL_FUNC); - - /* Wait for a minimal response. */ - timeout = jiffies + HZ; - while (atomic_read (&data.unstarted_count) > 0 - && time_before (jiffies, timeout)) - barrier(); - - /* If there's no response yet, log a message but allow a longer - * timeout period -- if we get a response this time, log - * a message saying when we got it.. - */ - if (atomic_read(&data.unstarted_count) > 0) { - long start_time = jiffies; - printk(KERN_ERR "%s: initial timeout -- trying long wait\n", - __func__); - timeout = jiffies + 30 * HZ; - while (atomic_read(&data.unstarted_count) > 0 - && time_before(jiffies, timeout)) - barrier(); - if (atomic_read(&data.unstarted_count) <= 0) { - long delta = jiffies - start_time; - printk(KERN_ERR - "%s: response %ld.%ld seconds into long wait\n", - __func__, delta / HZ, - (100 * (delta - ((delta / HZ) * HZ))) / HZ); - } - } - - /* We either got one or timed out -- clear the lock. */ - mb(); - smp_call_function_data = NULL; - - /* - * If after both the initial and long timeout periods we still don't - * have a response, something is very wrong... - */ - BUG_ON(atomic_read (&data.unstarted_count) > 0); - - /* Wait for a complete response, if needed. */ - if (wait) { - while (atomic_read (&data.unfinished_count) > 0) - barrier(); - } - - return 0; + send_ipi_message(mask, IPI_CALL_FUNC); } -EXPORT_SYMBOL(smp_call_function_on_cpu); -int -smp_call_function (void (*func) (void *info), void *info, int retry, int wait) +void arch_send_call_function_single_ipi(int cpu) { - return smp_call_function_on_cpu (func, info, retry, wait, - cpu_online_map); + send_ipi_message(cpumask_of_cpu(cpu), IPI_CALL_FUNC_SINGLE); } -EXPORT_SYMBOL(smp_call_function); static void ipi_imb(void *ignored) diff --git a/include/asm-alpha/smp.h b/include/asm-alpha/smp.h index 286e1d844f63..2f60a362d75e 100644 --- a/include/asm-alpha/smp.h +++ b/include/asm-alpha/smp.h @@ -47,7 +47,8 @@ extern struct cpuinfo_alpha cpu_data[NR_CPUS]; extern int smp_num_cpus; #define cpu_possible_map cpu_present_map -int smp_call_function_on_cpu(void (*func) (void *info), void *info,int retry, int wait, cpumask_t cpu); +extern void arch_send_call_function_single_ipi(int cpu); +extern void arch_send_call_function_ipi(cpumask_t mask); #else /* CONFIG_SMP */ -- GitLab