alpha: Add minimal support for software performance events

In the kernel the patch enables configuration of the perf event
option, adds the perf_event_open syscall, and includes a minimal
architecture specific asm/perf_event.h header file.

Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Matt Turner <mattst88@gmail.com>

4 files changed, 13 insertions, 1 deletions

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 443448154f32..bd7261ea8f94 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -9,6 +9,7 @@ config ALPHA
         select HAVE_IDE
         select HAVE_OPROFILE
         select HAVE_SYSCALL_WRAPPERS
+        select HAVE_PERF_EVENTS
         help
           The Alpha is a 64-bit general-purpose processor designed and
           marketed by the Digital Equipment Corporation of blessed memory,
diff --git a/arch/alpha/include/asm/perf_event.h b/arch/alpha/include/asm/perf_event.h
new file mode 100644
index 000000000000..3bef8522017c
--- /dev/null
+++ b/arch/alpha/include/asm/perf_event.h
@@ -0,0 +1,9 @@
+#ifndef __ASM_ALPHA_PERF_EVENT_H
+#define __ASM_ALPHA_PERF_EVENT_H
+
+/* Alpha only supports software events through this interface. */
+static inline void set_perf_event_pending(void) { }
+
+#define PERF_EVENT_INDEX_OFFSET 0
+
+#endif /* __ASM_ALPHA_PERF_EVENT_H */
diff --git a/arch/alpha/include/asm/unistd.h b/arch/alpha/include/asm/unistd.h
index 62e823e68f65..804e5311c841 100644
--- a/arch/alpha/include/asm/unistd.h
+++ b/arch/alpha/include/asm/unistd.h
@@ -448,10 +448,11 @@
 #define __NR_preadv                     490
 #define __NR_pwritev                    491
 #define __NR_rt_tgsigqueueinfo          492
+#define __NR_perf_event_open            493
 
 #ifdef __KERNEL__
 
-#define NR_SYSCALLS                     493
+#define NR_SYSCALLS                     494
 
 #define __ARCH_WANT_IPC_PARSE_VERSION
 #define __ARCH_WANT_OLD_READDIR
diff --git a/arch/alpha/kernel/systbls.S b/arch/alpha/kernel/systbls.S
index d0bc3c8c3ed3..09acb786e72b 100644
--- a/arch/alpha/kernel/systbls.S
+++ b/arch/alpha/kernel/systbls.S
@@ -511,6 +511,7 @@ sys_call_table:
         .quad sys_preadv                                /* 490 */
         .quad sys_pwritev
         .quad sys_rt_tgsigqueueinfo
+        .quad sys_perf_event_open
 
         .size sys_call_table, . - sys_call_table
         .type sys_call_table, @object