powerpc/smp: Support more IPI messages

This patch increases the number of demuxed messages for a
controller with a single ipi to 8 for 64-bit systems.

This is required because we want to use the IPI mechanism
to send messages from a CPU running in KVM real mode in a
guest to a CPU in the host to take some action. Currently,
we only support 4 messages and all 4 are already taken.

Define a fifth message PPC_MSG_RM_HOST_ACTION for this
purpose.

Signed-off-by: Suresh Warrier <warrier@linux.vnet.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
index 825663c..9ef9c37 100644 (file)
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -114,6 +114,9 @@ extern int cpu_to_core_id(int cpu);
 #define PPC_MSG_TICK_BROADCAST 2
 #define PPC_MSG_DEBUGGER_BREAK  3
 
+/* This is only used by the powernv kernel */
+#define PPC_MSG_RM_HOST_ACTION 4
+
 /* for irq controllers that have dedicated ipis per message (4) */
 extern int smp_request_message_ipi(int virq, int message);
 extern const char *smp_ipi_name[];

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ec9ec20..a53a130 100644 (file)
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -206,7 +206,7 @@ int smp_request_message_ipi(int virq, int msg)
 
 #ifdef CONFIG_PPC_SMP_MUXED_IPI
 struct cpu_messages {
-       int messages;                   /* current messages */
+       long messages;                  /* current messages */
        unsigned long data;             /* data for cause ipi */
 };
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct cpu_messages, ipi_message);
@@ -236,15 +236,15 @@ void smp_muxed_ipi_message_pass(int cpu, int msg)
 }
 
 #ifdef __BIG_ENDIAN__
-#define IPI_MESSAGE(A) (1 << (24 - 8 * (A)))
+#define IPI_MESSAGE(A) (1uL << ((BITS_PER_LONG - 8) - 8 * (A)))
 #else
-#define IPI_MESSAGE(A) (1 << (8 * (A)))
+#define IPI_MESSAGE(A) (1uL << (8 * (A)))
 #endif
 
 irqreturn_t smp_ipi_demux(void)
 {
        struct cpu_messages *info = this_cpu_ptr(&ipi_message);
-       unsigned int all;
+       unsigned long all;
 
        mb();   /* order any irq clear */