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[v2,2/9] powerpc/smp: Add smp_muxed_ipi_set_message

Message ID 1448495096-24759-3-git-send-email-warrier@linux.vnet.ibm.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Suresh E. Warrier Nov. 25, 2015, 11:44 p.m. UTC 
smp_muxed_ipi_message_pass() invokes smp_ops->cause_ipi, which
updates the MFFR through an ioremapped address, to cause the
IPI. Because of this real mode callers cannot call
smp_muxed_ipi_message_pass() for IPI messaging.

This patch creates a separate function smp_muxed_ipi_set_message
just to set the IPI message without the cause_ipi routine.
After calling this function to set the IPI message, real
mode callers must cause the IPI directly.

As part of this, we also change smp_muxed_ipi_message_pass
to call smp_muxed_ipi_set_message to set the message instead
of doing it directly inside the routine.

Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/smp.h | 1 +
 arch/powerpc/kernel/smp.c      | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

Comments

Michael Ellerman Dec. 7, 2015, 6:35 a.m. UTC | #1 
On Wed, 2015-25-11 at 23:44:49 UTC, "Suresh E. Warrier" wrote:
> smp_muxed_ipi_message_pass() invokes smp_ops->cause_ipi, which
> updates the MFFR through an ioremapped address, to cause the
> IPI. Because of this real mode callers cannot call
> smp_muxed_ipi_message_pass() for IPI messaging.

You're talking about the XICS code here but you don't mention that. Please
expand it to make it clear that you're talking about XICS.

cheers
diff mbox

Patch

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 9ef9c37..78083ed 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -124,6 +124,7 @@  extern const char *smp_ipi_name[];
 /* for irq controllers with only a single ipi */
 extern void smp_muxed_ipi_set_data(int cpu, unsigned long data);
 extern void smp_muxed_ipi_message_pass(int cpu, int msg);
+extern void smp_muxed_ipi_set_message(int cpu, int msg);
 extern irqreturn_t smp_ipi_demux(void);
 
 void smp_init_pSeries(void);
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index a53a130..e222efc 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -218,7 +218,7 @@  void smp_muxed_ipi_set_data(int cpu, unsigned long data)
 	info->data = data;
 }
 
-void smp_muxed_ipi_message_pass(int cpu, int msg)
+void smp_muxed_ipi_set_message(int cpu, int msg)
 {
 	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
 	char *message = (char *)&info->messages;
@@ -228,6 +228,13 @@  void smp_muxed_ipi_message_pass(int cpu, int msg)
 	 */
 	smp_mb();
 	message[msg] = 1;
+}
+
+void smp_muxed_ipi_message_pass(int cpu, int msg)
+{
+	struct cpu_messages *info = &per_cpu(ipi_message, cpu);
+
+	smp_muxed_ipi_set_message(cpu, msg);
 	/*
 	 * cause_ipi functions are required to include a full barrier
 	 * before doing whatever causes the IPI.