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Subject[PATCH 5/7] powerpc/perf: Define big-endian version of perf_mem_data_src

[PATCH 5/7] powerpc/perf: Define big-endian version of perf_mem_data_src

perf_mem_data_src is an union that is initialized via the ->val field
and accessed via the bitmap fields. For this to work on big endian
platforms, we also need a big-endian represenation of perf_mem_data_src.

Cc: Stephane Eranian <eranian@google.com>
Cc: Paul Mckerras <paulus@samba.org>
Cc: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
---
Thanks to input from Stephane Eranian and Michael Ellerman.

include/uapi/linux/perf_event.h | 55 +++++++++++++++++++++++++++++++++++++++
1 files changed, 55 insertions(+), 0 deletions(-)
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 62c25a2..8497c51 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -19,6 +19,47 @@
#include <asm/byteorder.h>

/*
+ * Kernel and userspace check for endianness in incompatible ways.
+ * In user space, <endian.h> defines both __BIG_ENDIAN and __LITTLE_ENDIAN
+ * but sets __BYTE_ORDER to one or the other. So user space uses checks are:
+ *
+ * #if __BYTE_ORDER == __LITTLE_ENDIAN
+ *
+ * In the kernel, __BYTE_ORDER is undefined, so using the above check doesn't
+ * work. Further, kernel code assumes that exactly one of __BIG_ENDIAN and
+ * __LITTLE_ENDIAN is defined. So the kernel checks are like:
+ *
+ * #if defined(__LITTLE_ENDIAN)
+ *
+ * But we can't use that check in user space since __LITTLE_ENDIAN (and
+ * __BIG_ENDIAN) are always defined.
+ *
+ * Since some perf data structures depend on endianness _and_ are shared
+ * between kernel and user, perf needs its own notion of endian macros (at
+ * least until user and kernel endian checks converge).
+ */
+#define __PERF_LE 1234
+#define __PERF_BE 4321
+
+#if defined(__KERNEL__)
+
+#if defined(__LITTLE_ENDIAN)
+#define __PERF_BYTE_ORDER __PERF_LE
+#elif defined(__BIG_ENDIAN)
+#define __PERF_BYTE_ORDER __PERF_BE
+#endif
+
+#else /* __KERNEL__ */
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define __PERF_BYTE_ORDER __PERF_LE
+#elif __BYTE_ORDER == __BIG_ENDIAN
+#define __PERF_BYTE_ORDER __PERF_BE
+#endif
+
+#endif /* __KERNEL__ */
+
+/*
* User-space ABI bits:
*/

@@ -659,6 +700,7 @@ enum perf_callchain_context {
#define PERF_FLAG_FD_OUTPUT (1U << 1)
#define PERF_FLAG_PID_CGROUP (1U << 2) /* pid=cgroup id, per-cpu mode only */

+#if __PERF_BYTE_ORDER == __PERF_LE
union perf_mem_data_src {
__u64 val;
struct {
@@ -670,6 +712,19 @@ union perf_mem_data_src {
mem_rsvd:31;
};
};
+#elif __PERF_BYTE_ORDER == __PERF_BE
+union perf_mem_data_src {
+ __u64 val;
+ struct {
+ __u64 mem_rsvd:31,
+ mem_dtlb:7, /* tlb access */
+ mem_lock:2, /* lock instr */
+ mem_snoop:5, /* snoop mode */
+ mem_lvl:14, /* memory hierarchy level */
+ mem_op:5; /* type of opcode */
+ };
+};
+#endif

/* type of opcode (load/store/prefetch,code) */
#define PERF_MEM_OP_NA 0x01 /* not available */
--
1.7.1


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