powerpc/xmon: Fiddle xmon_depth_to_print logic in xmon_show_stack()

Currently xmon_depth_to_print is static and global, but it's only
ever used in xmon_show_stack().

At least with a modern compiler it's inlined, so there's no point
in it being static, we could #define it but it's only used in one
place.

By reworking the logic we can drop count and just decrement the
max value as a loop counter. Also switch to a while loop so we
actually print no more than 64 frames as you'd expect based on the
variable name.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index d940234b09ec..1f8d2f10a432 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -1281,21 +1281,19 @@ static void get_function_bounds(unsigned long pc, unsigned long *startp,
         catch_memory_errors = 0;
 }
 
-static int xmon_depth_to_print = 64;
-
 #define LRSAVE_OFFSET           (STACK_FRAME_LR_SAVE * sizeof(unsigned long))
 #define MARKER_OFFSET           (STACK_FRAME_MARKER * sizeof(unsigned long))
 
 static void xmon_show_stack(unsigned long sp, unsigned long lr,
                             unsigned long pc)
 {
+        int max_to_print = 64;
         unsigned long ip;
         unsigned long newsp;
         unsigned long marker;
-        int count = 0;
         struct pt_regs regs;
 
-        do {
+        while (max_to_print--) {
                 if (sp < PAGE_OFFSET) {
                         if (sp != 0)
                                 printf("SP (%lx) is in userspace\n", sp);
@@ -1366,7 +1364,7 @@ static void xmon_show_stack(unsigned long sp, unsigned long lr,
                         break;
 
                 sp = newsp;
-        } while (count++ < xmon_depth_to_print);
+        }
 }
 
 static void backtrace(struct pt_regs *excp)