sparc64: Improvde documentation and readability of atomic backoff code.

Document what's going on in asm/backoff.h with a large and descriptive
comment.  Refer to it above the cpu_relax() definition in
asm/processor_64.h

Rename the pause patching section to have "3insn" in it's name like
the other patching sections do.

Based upon feedback from Sam Ravnborg.

Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/arch/sparc/kernel/entry.h b/arch/sparc/kernel/entry.h
index 51742df..cc3c5cb 100644
--- a/arch/sparc/kernel/entry.h
+++ b/arch/sparc/kernel/entry.h
@@ -63,8 +63,8 @@
 	unsigned int	addr;
 	unsigned int	insns[3];
 };
-extern struct pause_patch_entry __pause_patch,
-	__pause_patch_end;
+extern struct pause_patch_entry __pause_3insn_patch,
+	__pause_3insn_patch_end;
 
 extern void __init per_cpu_patch(void);
 extern void sun4v_patch_1insn_range(struct sun4v_1insn_patch_entry *,
diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c
index b45cff4..0eaf005 100644
--- a/arch/sparc/kernel/setup_64.c
+++ b/arch/sparc/kernel/setup_64.c
@@ -320,8 +320,8 @@
 {
 	struct pause_patch_entry *p;
 
-	p = &__pause_patch;
-	while (p < &__pause_patch_end) {
+	p = &__pause_3insn_patch;
+	while (p < &__pause_3insn_patch_end) {
 		unsigned long i, addr = p->addr;
 
 		for (i = 0; i < 3; i++) {
diff --git a/arch/sparc/kernel/vmlinux.lds.S b/arch/sparc/kernel/vmlinux.lds.S
index 847f9f7..0bacceb 100644
--- a/arch/sparc/kernel/vmlinux.lds.S
+++ b/arch/sparc/kernel/vmlinux.lds.S
@@ -132,10 +132,10 @@
 		*(.popc_6insn_patch)
 		__popc_6insn_patch_end = .;
 	}
-	.pause_patch : {
-		__pause_patch = .;
-		*(.pause_patch)
-		__pause_patch_end = .;
+	.pause_3insn_patch : {
+		__pause_3insn_patch = .;
+		*(.pause_3insn_patch)
+		__pause_3insn_patch_end = .;
 	}
 	PERCPU_SECTION(SMP_CACHE_BYTES)