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sparc32,leon: Implemented SMP IPIs for LEON CPU

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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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Hellstrom 2011-05-02 00:08:52 +00:00 committed by David S. Miller
parent d6d048192b
commit 1ca0c808c6
3 changed files with 126 additions and 3 deletions
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4
arch/sparc/include/asm/leon.h
View File

@ -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
@ -351,9 +351,11 @@ 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 */

16
arch/sparc/kernel/entry.S
View File

@ -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:

109
arch/sparc/kernel/leon_smp.c
View File

@ -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)
@ -176,13 +182,16 @@ 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);
@ -237,7 +246,7 @@ 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();
@ -293,6 +302,99 @@ 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;
@ -446,6 +548,9 @@ 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 */