[Skiboot] [PATCH 2/3] external/gard: Update record clearing to match Hostboots expectations

[Cyril Bur]

When the gard tool is told to clear all the gard records it actually erases
the entire flash and inserts ECC bytes only for the size of the first gard
record.

The current method appears to have stopped working, Hostboot expects the
entire partition to have ECC bytes throughout the entire partition, and as
such the current method causes Hostboot to error and be unable to bring up
machines.

Signed-off-by: Cyril Bur <cyril.bur at au1.ibm.com>
---
 external/gard/gard.c | 105 +++++++++++++++++++++++++++++----------------------
 1 file changed, 59 insertions(+), 46 deletions(-)

diff --git a/external/gard/gard.c b/external/gard/gard.c
index 7b0ea2b..d22df70 100644
--- a/external/gard/gard.c
+++ b/external/gard/gard.c
@@ -479,73 +479,83 @@ static int do_show(struct gard_ctx *ctx, int argc, char **argv)
 
 static int do_clear_i(struct gard_ctx *ctx, int pos, struct gard_record *gard, void *priv)
 {
-	int largest = 0, rc = 0;
+	int largest, rc = 0;
 	char *buf;
 	struct gard_record null_gard;
 
-	if (!gard || !ctx)
+	if (!gard || !ctx || !priv)
 		return -1;
 
+	/* Not this one */
+	if (be32toh(gard->record_id) != *(uint32_t *)priv)
+		return 0;
+
 	memset(&null_gard, INT_MAX, sizeof(null_gard));
 
-	if (!priv) {
-		if (pos != 0)
-			/* We erased everything on the first iteration, don't bother */
-			return 0;
+	largest = get_largest_pos(ctx);
 
-		printf("Erasing the entire gard partition...");
-		rc = blocklevel_erase(ctx->bl, ctx->gard_data_pos, ctx->gard_data_len);
-		if (rc) {
-			fprintf(stderr, "\nCouldn't erase flash partition at 0x%08x for size %u\n",
-					ctx->gard_data_pos, ctx->gard_data_len);
-			return rc;
-		}
-		printf("done\n");
+	printf("Clearing gard record 0x%08x...", be32toh(gard->record_id));
 
-		ctx->gard_data_len = sizeof_gard(ctx);
-	} else if (be32toh(gard->record_id) == *(uint32_t *)priv) {
-		largest = get_largest_pos(ctx);
-		if (largest < 0 || pos > largest) {
-			/* Something went horribly wrong */
-			fprintf(stderr, "largest index out of range %d\n", largest);
-			return -1;
-		}
-
-		if (pos < largest) {
-			/* We're not clearing the last record, shift all the records up */
-			int buf_len = ((largest - pos) * sizeof(struct gard_record));
-			int buf_pos = ctx->gard_data_pos + ((pos + 1) * sizeof_gard(ctx));
-			buf = malloc(buf_len);
-			if (!buf)
-				return -ENOMEM;
+	if (largest < 0 || pos > largest) {
+		/* Something went horribly wrong */
+		fprintf(stderr, "largest index out of range %d\n", largest);
+		return -1;
+	}
 
-			rc = blocklevel_read(ctx->bl, buf_pos, buf, buf_len);
-			if (rc) {
-				free(buf);
-				fprintf(stderr, "Couldn't read from flash at 0x%08x for len 0x%08x\n", buf_pos, buf_len);
-				return rc;
-			}
+	if (pos < largest) {
+		/* We're not clearing the last record, shift all the records up */
+		int buf_len = ((largest - pos) * sizeof(struct gard_record));
+		int buf_pos = ctx->gard_data_pos + ((pos + 1) * sizeof_gard(ctx));
+		buf = malloc(buf_len);
+		if (!buf)
+			return -ENOMEM;
 
-			rc = blocklevel_smart_write(ctx->bl, buf_pos - sizeof_gard(ctx), buf, buf_len);
+		rc = blocklevel_read(ctx->bl, buf_pos, buf, buf_len);
+		if (rc) {
 			free(buf);
-			if (rc) {
-				fprintf(stderr, "Couldn't write to flash at 0x%08lx for len 0x%08x\n",
-				        buf_pos - sizeof_gard(ctx), buf_len);
-				return rc;
-			}
+			fprintf(stderr, "Couldn't read from flash at 0x%08x for len 0x%08x\n", buf_pos, buf_len);
+			return rc;
 		}
 
-		ctx->gard_data_len -= sizeof_gard(ctx);
-		printf("Cleared gard record with id ID 0x%08x\n", be32toh(gard->record_id));
+		rc = blocklevel_smart_write(ctx->bl, buf_pos - sizeof_gard(ctx), buf, buf_len);
+		free(buf);
+		if (rc) {
+			fprintf(stderr, "Couldn't write to flash at 0x%08lx for len 0x%08x\n",
+			        buf_pos - sizeof_gard(ctx), buf_len);
+			return rc;
+		}
 	}
 
 	/* Now wipe the last record */
 	rc = blocklevel_smart_write(ctx->bl, ctx->gard_data_pos + (largest * sizeof_gard(ctx)),
-		                            &null_gard, sizeof(null_gard));
+	                            &null_gard, sizeof(null_gard));
+	printf("done\n");
 
 	return rc;
 }
 
+static int reset_partition(struct gard_ctx *ctx)
+{
+	int i, rc;
+	struct gard_record gard;
+	memset(&gard, INT_MAX, sizeof(gard));
+
+	rc = blocklevel_erase(ctx->bl, ctx->gard_data_pos, ctx->gard_data_len);
+	if (rc) {
+		fprintf(stderr, "Couldn't erase the gard partition. Bailing out\n");
+		return rc;
+	}
+	for (i = 0; i + sizeof_gard(ctx) < ctx->gard_data_len; i += sizeof_gard(ctx)) {
+		rc = blocklevel_write(ctx->bl, ctx->gard_data_pos + i, &gard, sizeof(gard));
+		if (rc) {
+			fprintf(stderr, "Couldn't reset the entire gard partition. Bailing out\n");
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
 static int do_clear(struct gard_ctx *ctx, int argc, char **argv)
 {
 	int rc;
@@ -557,7 +567,10 @@ static int do_clear(struct gard_ctx *ctx, int argc, char **argv)
 	}
 
 	if (strncmp(argv[1], "all", strlen("all")) == 0) {
-		rc = do_iterate(ctx, do_clear_i, NULL);
+		printf("Clearing the entire gard partition...");
+		fflush(stdout);
+		rc = reset_partition(ctx);
+		printf("done\n");
 	} else {
 		id = strtoul(argv[1], NULL, 16);
 		rc = do_iterate(ctx, do_clear_i, &id);
-- 
2.5.1