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 <daniel@xxxxxxxxxxx>
---
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(+), 0 deletions(-)
diff --git a/arch/sparc/kernel/irq.h b/arch/sparc/kernel/irq.h
index a189c27..100b9c2 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 b830914..a9ea60e 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 475d50b..dcbabe2 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];
@@ -120,6 +121,7 @@ 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();
@@ -191,6 +193,80 @@ 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;
@@ -356,6 +432,9 @@ 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;
--
1.5.4
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
