core: Add subid to load_resource()

This adds a subid to load_resource() so that sub-partitions can be accessed
inside a PNOR partition.  These sub-partitions follow the format used by the
hostboot SBE image.

The subid will match on the EC field of the SBE table of contents.  If it's
found, only that sub-partition is returned to the caller.

Current partitions (kernel and ramfs) don't support sub-partitions.  If caller
tries to access a sub-partition within these, we fail the call.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

2 files changed, 121 insertions, 7 deletions

diff --git a/platforms/astbmc/astbmc.h b/platforms/astbmc/astbmc.h
index 7e33f61..cff4757 100644
--- a/platforms/astbmc/astbmc.h
+++ b/platforms/astbmc/astbmc.h
@@ -24,6 +24,8 @@ extern int64_t astbmc_ipmi_power_down(uint64_t request);
 extern void astbmc_init(void);
 extern void astbmc_ext_irq(unsigned int chip_id);
 extern int pnor_init(void);
-extern bool pnor_load_resource(enum resource_id id, void *buf, size_t *len);
+extern int pnor_load_part(const char *name, void *addr, size_t *len);
+extern bool pnor_load_resource(enum resource_id id, uint32_t subid,
+			       void *buf, size_t *len);
 
 #endif /* __ASTBMC_H */
diff --git a/platforms/astbmc/pnor.c b/platforms/astbmc/pnor.c
index 2cdb29b..c566877 100644
--- a/platforms/astbmc/pnor.c
+++ b/platforms/astbmc/pnor.c
@@ -84,15 +84,110 @@ int pnor_init(void)
 	return rc;
 }
 
-static const struct {
-	enum resource_id id;
-	char name[PART_NAME_MAX+1];
+static struct {
+	enum resource_id	id;
+	uint32_t		subid;
+	char			name[PART_NAME_MAX+1];
 } part_name_map[] = {
-	{ RESOURCE_ID_KERNEL, "KERNEL" },
-	{ RESOURCE_ID_INITRAMFS, "ROOTFS" },
+	{ RESOURCE_ID_KERNEL,	RESOURCE_SUBID_NONE,		"KERNEL" },
+	{ RESOURCE_ID_INITRAMFS,RESOURCE_SUBID_NONE,		"ROOTFS" },
 };
 
-bool pnor_load_resource(enum resource_id id, void *buf, size_t *len)
+/* This mimics the hostboot SBE format */
+#define PNOR_SUBPART_ALIGNMENT 0x1000
+#define PNOR_SUBPART_HEADER_SIZE PNOR_SUBPART_ALIGNMENT
+struct pnor_hostboot_toc {
+	be32 ec;
+	be32 offset; /* From start of header.  4K aligned */
+	be32 size;
+};
+#define PNOR_HOSTBOOT_TOC_MAX_ENTRIES ((PNOR_SUBPART_HEADER_SIZE - 8)/sizeof(struct pnor_hostboot_toc))
+struct pnor_hostboot_header {
+	char eyecatcher[4];
+	be32 version;
+	struct pnor_hostboot_toc toc[PNOR_HOSTBOOT_TOC_MAX_ENTRIES];
+};
+
+static int pnor_find_subpartition(struct flash_chip *chip,
+			      uint32_t subid,
+			      uint32_t *start,
+			      uint32_t *total_size)
+{
+	struct pnor_hostboot_header *header;
+	uint32_t i;
+	bool rc;
+	char eyecatcher[5];
+
+	header = malloc(PNOR_SUBPART_HEADER_SIZE);
+	if (!header)
+		return false;
+
+	/* Get the TOC */
+	rc = flash_read(chip, *start, header, PNOR_SUBPART_HEADER_SIZE);
+	if (rc) {
+		prerror("PLAT: pnor subpartition TOC read failed %i", rc);
+		goto end;
+	}
+
+	/* Perform sanity */
+	i = be32_to_cpu(header->version);
+	if (i != 1) {
+		prerror("PLAT: pnor subpartition TOC version unknown %i", i);
+		rc = OPAL_RESOURCE;
+		goto end;
+	}
+	/* NULL terminate eyecatcher */
+	strncpy(eyecatcher, header->eyecatcher, 4);
+	eyecatcher[4] = 0;
+	printf("PLAT: pnor subpartition eyecatcher %s\n", eyecatcher);
+
+	rc = OPAL_RESOURCE;
+	for (i = 0; i< PNOR_HOSTBOOT_TOC_MAX_ENTRIES; i++) {
+		uint32_t ec, offset, size;
+
+		ec = be32_to_cpu(header->toc[i].ec);
+		offset = be32_to_cpu(header->toc[i].offset);
+		size = be32_to_cpu(header->toc[i].size);
+		/* Check for null terminating entry */
+		if (!ec && !offset && !size) {
+			prerror("PLAT: pnor subpartition not found.");
+			goto end;
+		}
+
+		if (ec != subid)
+			continue;
+
+		/* Sanity check the offset and size */
+		if (offset + size > *total_size) {
+			prerror("PLAT: pnor subpartition too big: %i", i);
+			goto end;
+		}
+		if (!size) {
+			prerror("PLAT: pnor subpartition zero size: %i", i);
+			goto end;
+		}
+		if (offset < PNOR_SUBPART_HEADER_SIZE) {
+			prerror("PLAT: pnor subpartition offset too small: %i", i);
+			goto end;
+		}
+
+		/* All good, let's adjust the start and size */
+		printf("PLAT: pnor found subpartition: %i size: %i offset %i\n",
+		       i, size, offset);
+		*start += offset;
+		size = (size + (PNOR_SUBPART_ALIGNMENT - 1)) & ~(PNOR_SUBPART_ALIGNMENT - 1);
+		*total_size = size;
+		rc = 0;
+		goto end;
+	}
+
+end:
+	free(header);
+	return rc;
+}
+
+bool pnor_load_resource(enum resource_id id, uint32_t subid,
+			void *buf, size_t *len)
 {
 	int i, rc, part_num, part_size, part_start;
 	const char *name;
@@ -111,6 +206,16 @@ bool pnor_load_resource(enum resource_id id, void *buf, size_t *len)
 		return false;
 	}
 
+	/*
+	 * If partition doesn't have a subindex but the caller specifies one,
+	 * we fail.  eg. kernel partition doesn't have a subindex
+	 */
+	if ((part_name_map[i].subid == RESOURCE_SUBID_NONE) &&
+	    (subid != RESOURCE_SUBID_NONE)) {
+		prerror("PLAT: Partition %s doesn't have subindex\n", name);
+		return false;
+	}
+
 	rc = ffs_lookup_part(pnor_ffs, name, &part_num);
 	if (rc) {
 		prerror("PLAT: No %s partition in PNOR\n", name);
@@ -123,6 +228,13 @@ bool pnor_load_resource(enum resource_id id, void *buf, size_t *len)
 		return false;
 	}
 
+	/* Find the sub partition if required */
+	if (subid != RESOURCE_SUBID_NONE) {
+		rc = pnor_find_subpartition(pnor_chip, subid, &part_start,
+					    &part_size);
+		if (rc)
+			return false;
+	}
 	if (part_size > *len) {
 		prerror("PLAT: %s image too large (%d > %zd)\n", name,
 			part_size, *len);