@@ -215,7 +215,7 @@ static inline int sparc_leon3_cpuid(void)
#endif /*!__ASSEMBLY__*/
#ifdef CONFIG_SMP
-# define LEON3_IRQ_RESCHEDULE 13
+# define LEON3_IRQ_IPI_DEFAULT 13
# define LEON3_IRQ_TICKER (leon3_ticker_irq)
# define LEON3_IRQ_CROSS_CALL 15
#endif
@@ -355,9 +355,11 @@ void leon_enable_irq_cpu(unsigned int irq_nr, unsigned int cpu);
extern irqreturn_t leon_percpu_timer_interrupt(int irq, void *unused);
extern unsigned int real_irq_entry[];
+extern unsigned int smpleon_ipi[];
extern unsigned int patchme_maybe_smp_msg[];
extern unsigned int t_nmi[], linux_trap_ipi15_leon[];
extern unsigned int linux_trap_ipi15_sun4m[];
+extern int leon_ipi_irq;
#endif /* CONFIG_SMP */
@@ -401,6 +401,22 @@ linux_trap_ipi15_sun4d:
1: b,a 1b
#ifdef CONFIG_SPARC_LEON
+ .globl smpleon_ipi
+ .extern leon_ipi_interrupt
+ /* SMP per-cpu IPI interrupts are handled specially. */
+smpleon_ipi:
+ SAVE_ALL
+ or %l0, PSR_PIL, %g2
+ wr %g2, 0x0, %psr
+ WRITE_PAUSE
+ wr %g2, PSR_ET, %psr
+ WRITE_PAUSE
+ call leonsmp_ipi_interrupt
+ add %sp, STACKFRAME_SZ, %o1 ! pt_regs
+ wr %l0, PSR_ET, %psr
+ WRITE_PAUSE
+ RESTORE_ALL
+
.align 4
.globl linux_trap_ipi15_leon
linux_trap_ipi15_leon:
@@ -14,6 +14,7 @@
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
+#include <linux/of.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
@@ -29,6 +30,7 @@
#include <asm/ptrace.h>
#include <asm/atomic.h>
#include <asm/irq_regs.h>
+#include <asm/traps.h>
#include <asm/delay.h>
#include <asm/irq.h>
@@ -52,6 +54,10 @@ static int smp_processors_ready;
extern volatile unsigned long cpu_callin_map[NR_CPUS];
extern cpumask_t smp_commenced_mask;
void __init leon_configure_cache_smp(void);
+static void leon_ipi_init(void);
+
+/* IRQ number of LEON IPIs */
+int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
static inline unsigned long do_swap(volatile unsigned long *ptr,
unsigned long val)
@@ -178,13 +184,16 @@ void __init leon_boot_cpus(void)
int nrcpu = leon_smp_nrcpus();
int me = smp_processor_id();
+ /* Setup IPI */
+ leon_ipi_init();
+
printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
(unsigned int)nrcpu, (unsigned int)NR_CPUS,
(unsigned int)&(leon3_irqctrl_regs->mpstatus));
leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
- leon_enable_irq_cpu(LEON3_IRQ_RESCHEDULE, me);
+ leon_enable_irq_cpu(leon_ipi_irq, me);
leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
@@ -239,7 +248,7 @@ int __cpuinit leon_boot_one_cpu(int i)
} else {
leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
- leon_enable_irq_cpu(LEON3_IRQ_RESCHEDULE, i);
+ leon_enable_irq_cpu(leon_ipi_irq, i);
}
local_flush_cache_all();
@@ -295,6 +304,99 @@ void leon_irq_rotate(int cpu)
{
}
+struct leon_ipi_work {
+ int single;
+ int msk;
+ int resched;
+};
+
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
+
+/* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
+ * is used for all three types of IPIs.
+ */
+static void __init leon_ipi_init(void)
+{
+ int cpu, len;
+ struct leon_ipi_work *work;
+ struct property *pp;
+ struct device_node *rootnp;
+ struct tt_entry *trap_table;
+ unsigned long flags;
+
+ /* Find IPI IRQ or stick with default value */
+ rootnp = of_find_node_by_path("/ambapp0");
+ if (rootnp) {
+ pp = of_find_property(rootnp, "ipi_num", &len);
+ if (pp && (*(int *)pp->value))
+ leon_ipi_irq = *(int *)pp->value;
+ }
+ printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
+
+ /* Adjust so that we jump directly to smpleon_ipi */
+ local_irq_save(flags);
+ trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
+ trap_table->inst_three += smpleon_ipi - real_irq_entry;
+ local_flush_cache_all();
+ local_irq_restore(flags);
+
+ for_each_possible_cpu(cpu) {
+ work = &per_cpu(leon_ipi_work, cpu);
+ work->single = work->msk = work->resched = 0;
+ }
+}
+
+static void leon_ipi_single(int cpu)
+{
+ struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
+
+ /* Mark work */
+ work->single = 1;
+
+ /* Generate IRQ on the CPU */
+ set_cpu_int(cpu, leon_ipi_irq);
+}
+
+static void leon_ipi_mask_one(int cpu)
+{
+ struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
+
+ /* Mark work */
+ work->msk = 1;
+
+ /* Generate IRQ on the CPU */
+ set_cpu_int(cpu, leon_ipi_irq);
+}
+
+static void leon_ipi_resched(int cpu)
+{
+ struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
+
+ /* Mark work */
+ work->resched = 1;
+
+ /* Generate IRQ on the CPU (any IRQ will cause resched) */
+ set_cpu_int(cpu, leon_ipi_irq);
+}
+
+void leonsmp_ipi_interrupt(void)
+{
+ struct leon_ipi_work *work = &__get_cpu_var(leon_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 struct smp_funcall {
smpfunc_t func;
unsigned long arg1;
@@ -448,6 +550,9 @@ void __init leon_init_smp(void)
BTFIXUPSET_CALL(smp_cross_call, leon_cross_call, BTFIXUPCALL_NORM);
BTFIXUPSET_CALL(__hard_smp_processor_id, __leon_processor_id,
BTFIXUPCALL_NORM);
+ BTFIXUPSET_CALL(smp_ipi_resched, leon_ipi_resched, BTFIXUPCALL_NORM);
+ BTFIXUPSET_CALL(smp_ipi_single, leon_ipi_single, BTFIXUPCALL_NORM);
+ BTFIXUPSET_CALL(smp_ipi_mask_one, leon_ipi_mask_one, BTFIXUPCALL_NORM);
}
#endif /* CONFIG_SPARC_LEON */
This patch implements SMP IPIs on LEON using software generated IRQs to signal between CPUs. The IPI IRQ number is set by using the ipi_num property in the device tree, or defaults to 13. LEON SMP systems should reserve IRQ 13 (and IRQ 15) to Linux in order for the defaults to work. Signed-off-by: Daniel Hellstrom <daniel@gaisler.com> --- arch/sparc/include/asm/leon.h | 4 +- arch/sparc/kernel/entry.S | 16 ++++++ arch/sparc/kernel/leon_smp.c | 109 ++++++++++++++++++++++++++++++++++++++++- 3 files changed, 126 insertions(+), 3 deletions(-)