powerpc: Add support for using doorbells for SMP IPI
The e500mc supports the new msgsnd/doorbell mechanisms that were added in
the Power ISA 2.05 architecture. We use the normal level doorbell for
doing SMP IPIs at this point.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 583ba64..dfec3d2 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -59,7 +59,7 @@
obj64-$(CONFIG_HIBERNATION) += swsusp_asm64.o
obj-$(CONFIG_MODULES) += module.o module_$(CONFIG_WORD_SIZE).o
obj-$(CONFIG_44x) += cpu_setup_44x.o
-obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o
+obj-$(CONFIG_FSL_BOOKE) += cpu_setup_fsl_booke.o dbell.o
extra-$(CONFIG_PPC_STD_MMU) := head_32.o
extra-$(CONFIG_PPC64) := head_64.o
diff --git a/arch/powerpc/kernel/dbell.c b/arch/powerpc/kernel/dbell.c
new file mode 100644
index 0000000..1493734
--- /dev/null
+++ b/arch/powerpc/kernel/dbell.c
@@ -0,0 +1,44 @@
+/*
+ * Author: Kumar Gala <galak@kernel.crashing.org>
+ *
+ * Copyright 2009 Freescale Semiconductor Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/threads.h>
+
+#include <asm/dbell.h>
+
+#ifdef CONFIG_SMP
+unsigned long dbell_smp_message[NR_CPUS];
+
+void smp_dbell_message_pass(int target, int msg)
+{
+ int i;
+
+ if(target < NR_CPUS) {
+ set_bit(msg, &dbell_smp_message[target]);
+ ppc_msgsnd(PPC_DBELL, 0, target);
+ }
+ else if(target == MSG_ALL_BUT_SELF) {
+ for_each_online_cpu(i) {
+ if (i == smp_processor_id())
+ continue;
+ set_bit(msg, &dbell_smp_message[i]);
+ ppc_msgsnd(PPC_DBELL, 0, i);
+ }
+ }
+ else { /* target == MSG_ALL */
+ for_each_online_cpu(i)
+ set_bit(msg, &dbell_smp_message[i]);
+ ppc_msgsnd(PPC_DBELL, PPC_DBELL_MSG_BRDCAST, 0);
+ }
+}
+#endif
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index 4ea6e1a..4c22620 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -698,7 +698,9 @@
/* Performance Monitor */
EXCEPTION(0x2060, PerformanceMonitor, performance_monitor_exception, EXC_XFER_STD)
- EXCEPTION(0x2070, Doorbell, unknown_exception, EXC_XFER_STD)
+ EXCEPTION(0x2070, Doorbell, doorbell_exception, EXC_XFER_STD)
+
+ CRITICAL_EXCEPTION(0x2080, CriticalDoorbell, unknown_exception)
/* Debug Interrupt */
DEBUG_DEBUG_EXCEPTION
@@ -921,6 +923,8 @@
mtspr SPRN_IVOR35,r3
li r3,Doorbell@l
mtspr SPRN_IVOR36,r3
+ li r3,CriticalDoorbell@l
+ mtspr SPRN_IVOR37,r3
sync
blr
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 970d66e..678fbff 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -53,6 +53,9 @@
#endif
#include <asm/kexec.h>
#include <asm/ppc-opcode.h>
+#ifdef CONFIG_FSL_BOOKE
+#include <asm/dbell.h>
+#endif
#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC)
int (*__debugger)(struct pt_regs *regs);
@@ -1122,6 +1125,24 @@
#endif /* CONFIG_VSX */
#ifdef CONFIG_FSL_BOOKE
+
+void doorbell_exception(struct pt_regs *regs)
+{
+#ifdef CONFIG_SMP
+ int cpu = smp_processor_id();
+ int msg;
+
+ if (num_online_cpus() < 2)
+ return;
+
+ for (msg = 0; msg < 4; msg++)
+ if (test_and_clear_bit(msg, &dbell_smp_message[cpu]))
+ smp_message_recv(msg);
+#else
+ printk(KERN_WARNING "Received doorbell on non-smp system\n");
+#endif
+}
+
void CacheLockingException(struct pt_regs *regs, unsigned long address,
unsigned long error_code)
{