Blackfin: SMP: add PM/CPU hotplug support
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/Kconfig b/arch/blackfin/Kconfig
index 0bd26db..c0d6d96 100644
--- a/arch/blackfin/Kconfig
+++ b/arch/blackfin/Kconfig
@@ -250,6 +250,11 @@
depends on SMP
default 2 if BF561
+config HOTPLUG_CPU
+ bool "Support for hot-pluggable CPUs"
+ depends on SMP && HOTPLUG
+ default y
+
config IRQ_PER_CPU
bool
depends on SMP
@@ -1130,7 +1135,6 @@
endmenu
menu "Power management options"
- depends on !SMP
source "kernel/power/Kconfig"
diff --git a/arch/blackfin/include/asm/smp.h b/arch/blackfin/include/asm/smp.h
index 6a0fe94..29fb882 100644
--- a/arch/blackfin/include/asm/smp.h
+++ b/arch/blackfin/include/asm/smp.h
@@ -25,5 +25,12 @@
void smp_icache_flush_range_others(unsigned long start,
unsigned long end);
+#ifdef CONFIG_HOTPLUG_CPU
+void coreb_sleep(u32 sic_iwr0, u32 sic_iwr1, u32 sic_iwr2);
+void cpu_die(void);
+void platform_cpu_die(void);
+int __cpu_disable(void);
+int __cpu_die(unsigned int cpu);
+#endif
#endif /* !__ASM_BLACKFIN_SMP_H */
diff --git a/arch/blackfin/mach-bf561/Makefile b/arch/blackfin/mach-bf561/Makefile
index 59e18af..b340297 100644
--- a/arch/blackfin/mach-bf561/Makefile
+++ b/arch/blackfin/mach-bf561/Makefile
@@ -6,3 +6,4 @@
obj-$(CONFIG_BF561_COREB) += coreb.o
obj-$(CONFIG_SMP) += smp.o secondary.o atomic.o
+obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
diff --git a/arch/blackfin/mach-bf561/hotplug.c b/arch/blackfin/mach-bf561/hotplug.c
new file mode 100644
index 0000000..c95169b
--- /dev/null
+++ b/arch/blackfin/mach-bf561/hotplug.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright 2007-2009 Analog Devices Inc.
+ * Graff Yang <graf.yang@analog.com>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <asm/blackfin.h>
+#include <asm/smp.h>
+#define SIC_SYSIRQ(irq) (irq - (IRQ_CORETMR + 1))
+
+int hotplug_coreb;
+
+void platform_cpu_die(void)
+{
+ unsigned long iwr[2] = {0, 0};
+ unsigned long bank = SIC_SYSIRQ(IRQ_SUPPLE_0) / 32;
+ unsigned long bit = 1 << (SIC_SYSIRQ(IRQ_SUPPLE_0) % 32);
+
+ hotplug_coreb = 1;
+
+ iwr[bank] = bit;
+
+ /* disable core timer */
+ bfin_write_TCNTL(0);
+
+ /* clear ipi interrupt IRQ_SUPPLE_0 */
+ bfin_write_SICB_SYSCR(bfin_read_SICB_SYSCR() | (1 << (10 + 1)));
+ SSYNC();
+
+ coreb_sleep(iwr[0], iwr[1], 0);
+}
diff --git a/arch/blackfin/mach-bf561/secondary.S b/arch/blackfin/mach-bf561/secondary.S
index 8e60503..4624eeb 100644
--- a/arch/blackfin/mach-bf561/secondary.S
+++ b/arch/blackfin/mach-bf561/secondary.S
@@ -11,6 +11,7 @@
#include <linux/init.h>
#include <asm/blackfin.h>
#include <asm/asm-offsets.h>
+#include <asm/trace.h>
__INIT
@@ -62,6 +63,8 @@
M2 = r0;
M3 = r0;
+ trace_buffer_init(p0,r0);
+
/* Turn off the icache */
p0.l = LO(IMEM_CONTROL);
p0.h = HI(IMEM_CONTROL);
@@ -159,6 +162,41 @@
ENDPROC(_coreb_trampoline_start)
ENTRY(_coreb_trampoline_end)
+.section ".text"
+ENTRY(_set_sicb_iwr)
+ P0.H = hi(SICB_IWR0);
+ P0.L = lo(SICB_IWR0);
+ P1.H = hi(SICB_IWR1);
+ P1.L = lo(SICB_IWR1);
+ [P0] = R0;
+ [P1] = R1;
+ SSYNC;
+ RTS;
+ENDPROC(_set_sicb_iwr)
+
+ENTRY(_coreb_sleep)
+ sp.l = lo(INITIAL_STACK);
+ sp.h = hi(INITIAL_STACK);
+ fp = sp;
+ usp = sp;
+
+ call _set_sicb_iwr;
+
+ CLI R2;
+ SSYNC;
+ IDLE;
+ STI R2;
+
+ R0 = IWR_DISABLE_ALL;
+ R1 = IWR_DISABLE_ALL;
+ call _set_sicb_iwr;
+
+ p0.h = hi(COREB_L1_CODE_START);
+ p0.l = lo(COREB_L1_CODE_START);
+ jump (p0);
+ENDPROC(_coreb_sleep)
+
+__CPUINIT
ENTRY(_coreb_start)
[--sp] = reti;
@@ -176,12 +214,20 @@
sp = [p0];
usp = sp;
fp = sp;
+#ifdef CONFIG_HOTPLUG_CPU
+ p0.l = _hotplug_coreb;
+ p0.h = _hotplug_coreb;
+ r0 = [p0];
+ cc = BITTST(r0, 0);
+ if cc jump 3f;
+#endif
sp += -12;
call _init_pda
sp += 12;
+#ifdef CONFIG_HOTPLUG_CPU
+3:
+#endif
call _secondary_start_kernel;
.L_exit:
jump.s .L_exit;
ENDPROC(_coreb_start)
-
-__FINIT
diff --git a/arch/blackfin/mach-bf561/smp.c b/arch/blackfin/mach-bf561/smp.c
index 9036942..3b9a4bf 100644
--- a/arch/blackfin/mach-bf561/smp.c
+++ b/arch/blackfin/mach-bf561/smp.c
@@ -65,6 +65,8 @@
bfin_write_SICB_IAR5(bfin_read_SICA_IAR5());
bfin_write_SICB_IAR6(bfin_read_SICA_IAR6());
bfin_write_SICB_IAR7(bfin_read_SICA_IAR7());
+ bfin_write_SICB_IWR0(IWR_DISABLE_ALL);
+ bfin_write_SICB_IWR1(IWR_DISABLE_ALL);
SSYNC();
/* Store CPU-private information to the cpu_data array. */
@@ -80,17 +82,18 @@
{
unsigned long timeout;
- /* CoreB already running?! */
- BUG_ON((bfin_read_SICA_SYSCR() & COREB_SRAM_INIT) == 0);
-
printk(KERN_INFO "Booting Core B.\n");
spin_lock(&boot_lock);
- /* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
- SSYNC();
- bfin_write_SICA_SYSCR(bfin_read_SICA_SYSCR() & ~COREB_SRAM_INIT);
- SSYNC();
+ if ((bfin_read_SICA_SYSCR() & COREB_SRAM_INIT) == 0) {
+ /* CoreB already running, sending ipi to wakeup it */
+ platform_send_ipi_cpu(cpu, IRQ_SUPPLE_0);
+ } else {
+ /* Kick CoreB, which should start execution from CORE_SRAM_BASE. */
+ bfin_write_SICA_SYSCR(bfin_read_SICA_SYSCR() & ~COREB_SRAM_INIT);
+ SSYNC();
+ }
timeout = jiffies + 1 * HZ;
while (time_before(jiffies, timeout)) {
diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
index b343ab3..efc47ff 100644
--- a/arch/blackfin/mach-common/smp.c
+++ b/arch/blackfin/mach-common/smp.c
@@ -344,8 +344,11 @@
int __cpuinit __cpu_up(unsigned int cpu)
{
- struct task_struct *idle;
int ret;
+ static struct task_struct *idle;
+
+ if (idle)
+ free_task(idle);
idle = fork_idle(cpu);
if (IS_ERR(idle)) {
@@ -354,7 +357,6 @@
}
secondary_stack = task_stack_page(idle) + THREAD_SIZE;
- smp_wmb();
ret = platform_boot_secondary(cpu, idle);
@@ -413,7 +415,6 @@
atomic_inc(&mm->mm_users);
atomic_inc(&mm->mm_count);
current->active_mm = mm;
- BUG_ON(current->mm); /* Can't be, but better be safe than sorry. */
preempt_disable();
@@ -495,3 +496,34 @@
}
EXPORT_SYMBOL(resync_core_dcache);
#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+int __cpuexit __cpu_disable(void)
+{
+ unsigned int cpu = smp_processor_id();
+
+ if (cpu == 0)
+ return -EPERM;
+
+ set_cpu_online(cpu, false);
+ return 0;
+}
+
+static DECLARE_COMPLETION(cpu_killed);
+
+int __cpuexit __cpu_die(unsigned int cpu)
+{
+ return wait_for_completion_timeout(&cpu_killed, 5000);
+}
+
+void cpu_die(void)
+{
+ complete(&cpu_killed);
+
+ atomic_dec(&init_mm.mm_users);
+ atomic_dec(&init_mm.mm_count);
+
+ local_irq_disable();
+ platform_cpu_die();
+}
+#endif