Skip to content

Commit

Permalink
powerpc/smp: Support more IPI messages
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
Suresh Warrier authored and Paul Mackerras committed Feb 29, 2016
1 parent d3695aa commit bd7f561
Show file tree
Hide file tree
Showing 2 changed files with 7 additions and 4 deletions.
3 changes: 3 additions & 0 deletions arch/powerpc/include/asm/smp.h
Original file line number Diff line number Diff line change
Expand Up @@ -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[];
Expand Down
8 changes: 4 additions & 4 deletions arch/powerpc/kernel/smp.c
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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 */

Expand Down

0 comments on commit bd7f561

Please sign in to comment.