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powerpc/smp: Support more IPI messages

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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>
This commit is contained in:
Suresh Warrier 2015-12-17 14:59:03 -06:00 committed by Paul Mackerras
parent d3695aa4f4
commit bd7f561f76
2 changed files with 7 additions and 4 deletions
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3
arch/powerpc/include/asm/smp.h
View File

@ -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[];

8
arch/powerpc/kernel/smp.c
View File

@ -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 */