[CELL] oprofile: add support to OProfile for profiling CELL BE SPUs

From: Maynard Johnson <mpjohn@us.ibm.com>

This patch updates the existing arch/powerpc/oprofile/op_model_cell.c
to add in the SPU profiling capabilities.  In addition, a 'cell' subdirectory
was added to arch/powerpc/oprofile to hold Cell-specific SPU profiling code.
Exports spu_set_profile_private_kref and spu_get_profile_private_kref which
are used by OProfile to store private profile information in spufs data
structures.

Also incorporated several fixes from other patches (rrn).  Check pointer
returned from kzalloc.  Eliminated unnecessary cast.  Better error
handling and cleanup in the related area.  64-bit unsigned long parameter
was being demoted to 32-bit unsigned int and eventually promoted back to
unsigned long.

Signed-off-by: Carl Love <carll@us.ibm.com>
Signed-off-by: Maynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: Bob Nelson <rrnelson@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h
index 24f352d..a0f7fc8 100644
--- a/include/asm-powerpc/spu.h
+++ b/include/asm-powerpc/spu.h
@@ -138,6 +138,7 @@
 	struct spu_runqueue *rq;
 	unsigned long long timestamp;
 	pid_t pid;
+	pid_t tgid;
 	int class_0_pending;
 	spinlock_t register_lock;
 
@@ -217,6 +218,20 @@
 struct mm_struct;
 extern void spu_flush_all_slbs(struct mm_struct *mm);
 
+/* This interface allows a profiler (e.g., OProfile) to store a ref
+ * to spu context information that it creates.	This caching technique
+ * avoids the need to recreate this information after a save/restore operation.
+ *
+ * Assumes the caller has already incremented the ref count to
+ * profile_info; then spu_context_destroy must call kref_put
+ * on prof_info_kref.
+ */
+void spu_set_profile_private_kref(struct spu_context *ctx,
+				  struct kref *prof_info_kref,
+				  void ( * prof_info_release) (struct kref *kref));
+
+void *spu_get_profile_private_kref(struct spu_context *ctx);
+
 /* system callbacks from the SPU */
 struct spu_syscall_block {
 	u64 nr_ret;