[U-Boot-Users] Problem with cache diag on sequoia board in PPC4xx branch for-1.3.2

[Stefan Roese]

On Saturday 22 December 2007, Stefan Roese wrote:
> > In testing my merge of Korat PPC440EPx board support into PPC4xx branch
> > "for-1.3.2", I found problem with the "DIAG RUN CACHE" command.  The
> > same problem occurs in the latest for-1.3.2 code for sequoia.  Here is a
> > copy of the console output showing what happens:
>
> Thanks for reporting. I'll try to take a look at it in the next days. But I
> have no problems at all, if you provide a patch to fix it. ;)

OK, I found the problem and fixed in the for-1.3.2 branch:

commit 8092791c5d959e89f9bc4ed0ff880c3509da743f
Author: Stefan Roese <sr at denx.de>
Date:   Sat Dec 22 12:18:26 2007 +0100

    ppc4xx: Fix problem in 44x cache POST routine

    As repoted by Larry Johnson, running "diag run cache" caused a crash
    in U-Boot. This problem was introduced by a patch that removed the
    TLB entry for the cache test after the test has completed. Since this
    TLB was only setup once, a 2nd attempt to run this cache test
    failed with a crash. Now this TLB entry is created every time the
    routine is called.

    Signed-off-by: Stefan Roese <sr at denx.de>

diff --git a/post/cpu/ppc4xx/cache.c b/post/cpu/ppc4xx/cache.c
index 30d5088..c8ddf35 100644
--- a/post/cpu/ppc4xx/cache.c
+++ b/post/cpu/ppc4xx/cache.c
@@ -51,8 +51,6 @@ int cache_post_test4 (int tlb, void *p, int size);
 int cache_post_test5 (int tlb, void *p, int size);
 int cache_post_test6 (int tlb, void *p, int size);

-static int tlb = -1;           /* index to the victim TLB entry */
-
 #ifdef CONFIG_440
 static unsigned char testarea[CACHE_POST_SIZE]
 __attribute__((__aligned__(CACHE_POST_SIZE)));
@@ -60,7 +58,7 @@ __attribute__((__aligned__(CACHE_POST_SIZE)));

 int cache_post_test (int flags)
 {
-       void* virt = (void*)CFG_POST_CACHE_ADDR;
+       void *virt = (void *)CFG_POST_CACHE_ADDR;
        int ints;
        int res = 0;

@@ -72,26 +70,25 @@ int cache_post_test (int flags)
         */
 #ifdef CONFIG_440
        int word0, i;
+       int tlb;                /* index to the victim TLB entry */

-       if (tlb < 0) {
-               /*
-                * Allocate a new TLB entry, since we are going to modify
-                * the write-through and caching inhibited storage attributes.
-                */
-               program_tlb((u32)testarea, (u32)virt,
-                           CACHE_POST_SIZE, TLB_WORD2_I_ENABLE);
-
-               /* Find the TLB entry */
-               for (i = 0;; i++) {
-                       if (i >= PPC4XX_TLB_SIZE) {
-                               printf ("Failed to program tlb entry\n");
-                               return -1;
-                       }
-                       word0 = mftlb1(i);
-                       if (TLB_WORD0_EPN_DECODE(word0) == (u32)virt) {
-                               tlb = i;
-                               break;
-                       }
+       /*
+        * Allocate a new TLB entry, since we are going to modify
+        * the write-through and caching inhibited storage attributes.
+        */
+       program_tlb((u32)testarea, (u32)virt, CACHE_POST_SIZE,
+                   TLB_WORD2_I_ENABLE);
+
+       /* Find the TLB entry */
+       for (i = 0;; i++) {
+               if (i >= PPC4XX_TLB_SIZE) {
+                       printf ("Failed to program tlb entry\n");
+                       return -1;
+               }
+               word0 = mftlb1(i);
+               if (TLB_WORD0_EPN_DECODE(word0) == (u32)virt) {
+                       tlb = i;
+                       break;
                }
        }
 #endif