From 55dd23eca666876e6028aa35d5e391cfced54871 Mon Sep 17 00:00:00 2001 From: Daniel Hellstrom Date: Mon, 2 May 2011 00:08:54 +0000 Subject: sparc32, sun4d: Implemented SMP IPIs support for SUN4D machines The sun4d does not seem to have a distingstion between soft and hard IRQs. When generating IPIs the generated IRQ looks like a hard IRQ, this patch adds a "IPI check" in the sun4d irq trap handler at a predefined IRQ number (SUN4D_IPI_IRQ). Before generating an IPI a per-cpu memory structure is modified for the "IPI check" to successfully detect a IPI request to a specific processor, the check clears the IPI work requested. All three IPIs (resched, single and cpu-mask) use the same IRQ number. The IPI IRQ should preferrably be on a separate IRQ and definitly not shared with IRQ handlers requesting IRQ with IRQF_SHARED. Signed-off-by: Daniel Hellstrom Signed-off-by: David S. Miller --- arch/sparc/kernel/irq.h | 6 ++++ arch/sparc/kernel/sun4d_irq.c | 9 +++++ arch/sparc/kernel/sun4d_smp.c | 79 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 94 insertions(+) (limited to 'arch') diff --git a/arch/sparc/kernel/irq.h b/arch/sparc/kernel/irq.h index a189c273f638..100b9c204e78 100644 --- a/arch/sparc/kernel/irq.h +++ b/arch/sparc/kernel/irq.h @@ -86,4 +86,10 @@ BTFIXUPDEF_CALL(void, set_irq_udt, int) #define set_cpu_int(cpu,level) BTFIXUP_CALL(set_cpu_int)(cpu,level) #define clear_cpu_int(cpu,level) BTFIXUP_CALL(clear_cpu_int)(cpu,level) #define set_irq_udt(cpu) BTFIXUP_CALL(set_irq_udt)(cpu) + +/* All SUN4D IPIs are sent on this IRQ, may be shared with hard IRQs */ +#define SUN4D_IPI_IRQ 14 + +extern void sun4d_ipi_interrupt(void); + #endif diff --git a/arch/sparc/kernel/sun4d_irq.c b/arch/sparc/kernel/sun4d_irq.c index b830914e32d3..a9ea60eb2c10 100644 --- a/arch/sparc/kernel/sun4d_irq.c +++ b/arch/sparc/kernel/sun4d_irq.c @@ -156,6 +156,15 @@ void sun4d_handler_irq(int pil, struct pt_regs *regs) cc_set_iclr(1 << pil); +#ifdef CONFIG_SMP + /* + * Check IPI data structures after IRQ has been cleared. Hard and Soft + * IRQ can happen at the same time, so both cases are always handled. + */ + if (pil == SUN4D_IPI_IRQ) + sun4d_ipi_interrupt(); +#endif + old_regs = set_irq_regs(regs); irq_enter(); if (sbusl == 0) { diff --git a/arch/sparc/kernel/sun4d_smp.c b/arch/sparc/kernel/sun4d_smp.c index 38423a05ae41..30ca6245692f 100644 --- a/arch/sparc/kernel/sun4d_smp.c +++ b/arch/sparc/kernel/sun4d_smp.c @@ -32,6 +32,7 @@ static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned lon return val; } +static void smp4d_ipi_init(void); static void smp_setup_percpu_timer(void); static unsigned char cpu_leds[32]; @@ -118,6 +119,7 @@ void __cpuinit smp4d_callin(void) */ void __init smp4d_boot_cpus(void) { + smp4d_ipi_init(); if (boot_cpu_id) current_set[0] = NULL; smp_setup_percpu_timer(); @@ -189,6 +191,80 @@ void __init smp4d_smp_done(void) sun4d_distribute_irqs(); } +/* Memory structure giving interrupt handler information about IPI generated */ +struct sun4d_ipi_work { + int single; + int msk; + int resched; +}; + +static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work); + +/* Initialize IPIs on the SUN4D SMP machine */ +static void __init smp4d_ipi_init(void) +{ + int cpu; + struct sun4d_ipi_work *work; + + printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ); + + for_each_possible_cpu(cpu) { + work = &per_cpu(sun4d_ipi_work, cpu); + work->single = work->msk = work->resched = 0; + } +} + +void sun4d_ipi_interrupt(void) +{ + struct sun4d_ipi_work *work = &__get_cpu_var(sun4d_ipi_work); + + if (work->single) { + work->single = 0; + smp_call_function_single_interrupt(); + } + if (work->msk) { + work->msk = 0; + smp_call_function_interrupt(); + } + if (work->resched) { + work->resched = 0; + smp_resched_interrupt(); + } +} + +static void smp4d_ipi_single(int cpu) +{ + struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu); + + /* Mark work */ + work->single = 1; + + /* Generate IRQ on the CPU */ + sun4d_send_ipi(cpu, SUN4D_IPI_IRQ); +} + +static void smp4d_ipi_mask_one(int cpu) +{ + struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu); + + /* Mark work */ + work->msk = 1; + + /* Generate IRQ on the CPU */ + sun4d_send_ipi(cpu, SUN4D_IPI_IRQ); +} + +static void smp4d_ipi_resched(int cpu) +{ + struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu); + + /* Mark work */ + work->resched = 1; + + /* Generate IRQ on the CPU (any IRQ will cause resched) */ + sun4d_send_ipi(cpu, SUN4D_IPI_IRQ); +} + static struct smp_funcall { smpfunc_t func; unsigned long arg1; @@ -354,6 +430,9 @@ void __init sun4d_init_smp(void) BTFIXUPSET_BLACKBOX(load_current, smp4d_blackbox_current); BTFIXUPSET_CALL(smp_cross_call, smp4d_cross_call, BTFIXUPCALL_NORM); BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4d_processor_id, BTFIXUPCALL_NORM); + BTFIXUPSET_CALL(smp_ipi_resched, smp4d_ipi_resched, BTFIXUPCALL_NORM); + BTFIXUPSET_CALL(smp_ipi_single, smp4d_ipi_single, BTFIXUPCALL_NORM); + BTFIXUPSET_CALL(smp_ipi_mask_one, smp4d_ipi_mask_one, BTFIXUPCALL_NORM); for (i = 0; i < NR_CPUS; i++) { ccall_info.processors_in[i] = 1; -- cgit v1.2.3-59-g8ed1b