platform: add a platform hook for loading external resources

Currently, in core/init.c we do a fsp-specific load procedure to grab
the kernel image.

We'd like to do two things: allow other types of resources, and have
paths for non-FSP platforms to perform loads.

This change adds a platform-specific load_resource hook, and moves the
currently loading code to fsp_load_resource. To allow other resource
types, we add an identifier to indicate the type of resouce to load.

Signed-off-by: Jeremy Kerr <jeremy.kerr@au.ibm.com>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Acked-by: Stewart Smith <stewart@linux.vnet.ibm.com>

6 files changed, 78 insertions, 38 deletions

diff --git a/core/init.c b/core/init.c
index d88f759..bd360ac 100644
--- a/core/init.c
+++ b/core/init.c
@@ -260,12 +260,6 @@ static bool try_load_elf32(struct elf_hdr *header)
 	return true;
 }
 
-/* LID numbers. For now we hijack some of pHyp's own until i figure
- * out the whole business with the MasterLID
- */
-#define KERNEL_LID_PHYP	0x80a00701
-#define KERNEL_LID_OPAL	0x80f00101
-
 extern char __builtin_kernel_start[];
 extern char __builtin_kernel_end[];
 extern uint64_t boot_offset;
@@ -273,50 +267,34 @@ extern uint64_t boot_offset;
 static bool load_kernel(void)
 {
 	struct elf_hdr *kh;
-	uint32_t lid;
-	size_t ksize;
-	const char *ltype;
+	size_t ksize = 0;
 
-	ltype = dt_prop_get_def(dt_root, "lid-type", NULL);
+	/* Try to load an external kernel payload through the platform hooks */
+	if (platform.load_resource) {
+		ksize = KERNEL_LOAD_SIZE;
+		if (!platform.load_resource(RESOURCE_ID_KERNEL,
+				KERNEL_LOAD_BASE, &ksize)) {
+			printf("INIT: platform kernel load failed\n");
+			ksize = 0;
+		}
+	}
 
-	/* No lid-type, assume stradale, currently pre-loaded at fixed
-	 * address
-	 */
-	if (!ltype) {
-		printf("No lid-type property, assuming FSP-less setup\n");
+	/* Try embedded kernel payload */
+	if (!ksize) {
 		ksize = __builtin_kernel_end - __builtin_kernel_start;
 		if (ksize) {
 			/* Move the built-in kernel up */
 			uint64_t builtin_base =
 				((uint64_t)__builtin_kernel_start) -
-				SKIBOOT_BASE + boot_offset;    
+				SKIBOOT_BASE + boot_offset;
 			printf("Using built-in kernel\n");
 			memmove(KERNEL_LOAD_BASE, (void*)builtin_base, ksize);
-		} else
-			printf("Assuming kernel at 0x%p\n", KERNEL_LOAD_BASE);
-	} else {
-		ksize = KERNEL_LOAD_SIZE;
-
-		/* First try to load an OPAL secondary LID always */
-		lid = fsp_adjust_lid_side(KERNEL_LID_OPAL);
-		printf("Trying to load OPAL secondary LID...\n");
-		if (fsp_fetch_data(0, FSP_DATASET_NONSP_LID, lid, 0,
-				   KERNEL_LOAD_BASE, &ksize) != 0) {	
-			if (!strcmp(ltype, "opal")) {
-				prerror("Failed to load in OPAL mode...\n");
-				return false;
-			}
-			printf("Trying to load as PHYP LID...\n");
-			lid = fsp_adjust_lid_side(KERNEL_LID_PHYP);
-			ksize = KERNEL_LOAD_SIZE;
-			if (fsp_fetch_data(0, FSP_DATASET_NONSP_LID, lid, 0,
-					   KERNEL_LOAD_BASE, &ksize) != 0) {	
-				prerror("Failed to load kernel\n");
-				return false;
-			}
 		}
 	}
 
+	if (!ksize)
+		printf("Assuming kernel at 0x%p\n", KERNEL_LOAD_BASE);
+
 	printf("INIT: Kernel loaded, size: %zu bytes (0 = unknown preload)\n",
 	       ksize);
 
diff --git a/hw/fsp/fsp.c b/hw/fsp/fsp.c
index 51d06b0..7a07835 100644
--- a/hw/fsp/fsp.c
+++ b/hw/fsp/fsp.c
@@ -98,6 +98,12 @@ static u64 fsp_hir_timeout;
 #define FSP_CRITICAL_OP_TIMEOUT		128
 #define FSP_DRCR_CLEAR_TIMEOUT		128
 
+/* LID numbers. For now we hijack some of pHyp's own until i figure
+ * out the whole business with the MasterLID
+ */
+#define KERNEL_LID_PHYP			0x80a00701
+#define KERNEL_LID_OPAL			0x80f00101
+
 /*
  * We keep track on last logged values for some things to print only on
  * value changes, but also to releive pressure on the tracer which
@@ -2171,6 +2177,48 @@ int fsp_fetch_data_queue(uint8_t flags, uint16_t id, uint32_t sub_id,
 	return OPAL_SUCCESS;
 }
 
+bool fsp_load_resource(enum resource_id id, void *buf, size_t *size)
+{
+	uint32_t lid_no, lid;
+	size_t tmp_size;
+	int rc;
+
+	switch (id) {
+	case RESOURCE_ID_KERNEL:
+		lid_no = KERNEL_LID_OPAL;
+		break;
+	default:
+		return false;
+	}
+
+retry:
+	tmp_size = *size;
+
+	printf("Trying to load OPAL LID %08x...\n", lid_no);
+	lid = fsp_adjust_lid_side(lid_no);
+	rc = fsp_fetch_data(0, FSP_DATASET_NONSP_LID, lid, 0, buf, &tmp_size);
+
+	/* Fall back to a PHYP LID for kernel loads */
+	if (rc && lid_no == KERNEL_LID_OPAL) {
+		const char *ltype = dt_prop_get_def(dt_root, "lid-type", NULL);
+		if (!ltype || strcmp(ltype, "opal")) {
+			prerror("Failed to load in OPAL mode...\n");
+			return false;
+		}
+		printf("Trying to load as PHYP LID...\n");
+		lid_no = KERNEL_LID_PHYP;
+		goto retry;
+	}
+
+	if (rc) {
+		prerror("Failed to load LID\n");
+		return false;
+	}
+
+	*size = tmp_size;
+	return true;
+}
+
 void fsp_used_by_console(void)
 {
 	fsp_lock.in_con_path = true;
diff --git a/include/fsp.h b/include/fsp.h
index 0464da4..e41498e 100644
--- a/include/fsp.h
+++ b/include/fsp.h
@@ -709,6 +709,7 @@ extern int fsp_fetch_data(uint8_t flags, uint16_t id, uint32_t sub_id,
 extern int fsp_fetch_data_queue(uint8_t flags, uint16_t id, uint32_t sub_id,
 				uint32_t offset, void *buffer, size_t *length,
 				void (*comp)(struct fsp_msg *msg));
+extern bool fsp_load_resource(enum resource_id id, void *buf, size_t *size);
 
 /* FSP console stuff */
 extern void fsp_console_preinit(void);
diff --git a/include/platform.h b/include/platform.h
index b916e5e..77d025b 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -22,6 +22,10 @@ struct phb;
 struct pci_device;
 struct errorlog;
 
+enum resource_id {
+	RESOURCE_ID_KERNEL,
+};
+
 /*
  * Each platform can provide a set of hooks
  * that can affect the generic code
@@ -119,6 +123,13 @@ struct platform {
 	uint32_t	(*occ_timeout)(void);
 
 	int		(*elog_commit)(struct errorlog *buf);
+
+	/*
+	 * Load an external resource (eg, kernel payload) into a preallocated
+	 * buffer. Returns true on success.
+	 */
+	bool		(*load_resource)(enum resource_id id,
+					 void *buf, size_t *len);
 };
 
 extern struct platform __platforms_start;
diff --git a/platforms/ibm-fsp/apollo.c b/platforms/ibm-fsp/apollo.c
index 37315ba..fc01e64 100644
--- a/platforms/ibm-fsp/apollo.c
+++ b/platforms/ibm-fsp/apollo.c
@@ -59,4 +59,5 @@ DECLARE_PLATFORM(apollo) = {
 	.nvram_start_read	= fsp_nvram_start_read,
 	.nvram_write		= fsp_nvram_write,
 	.elog_commit		= elog_fsp_commit,
+	.load_resource		= fsp_load_resource,
 };
diff --git a/platforms/ibm-fsp/firenze.c b/platforms/ibm-fsp/firenze.c
index b68dd70..29cbde0 100644
--- a/platforms/ibm-fsp/firenze.c
+++ b/platforms/ibm-fsp/firenze.c
@@ -248,4 +248,5 @@ DECLARE_PLATFORM(firenze) = {
 	.nvram_write		= fsp_nvram_write,
 	.occ_timeout		= ibm_fsp_occ_timeout,
 	.elog_commit		= elog_fsp_commit,
+	.load_resource		= fsp_load_resource,
 } ;