Commit bd7f561f authored by Suresh Warrier's avatar Suresh Warrier Committed by Paul Mackerras
Browse files

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: default avatarSuresh Warrier <warrier@linux.vnet.ibm.com>
Acked-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent d3695aa4

arch/powerpc/include/asm/smp.h

+3 −0
Original line number Diff line number Diff line
@@ -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[];

arch/powerpc/kernel/smp.c

+4 −4
Original line number Diff line number Diff line
@@ -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 */

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