[U-Boot] [PATCH] powerpc/85xx: verify the localbus device tree address before booting the OS

[Timur Tabi]

The localbus controller node in the device tree is typically a root node,
even though the controller is part of CCSR.  If we were to put the lbc
node under the SOC node, then the 'ranges' property in the lbc node would
translate through the 'ranges' property of the parent SOC node, and we
don't want that.

Since the lbc is a separate node, it's possible for the 'reg' property to
be wrong.  This happened with the original version of p1022ds.dts, which
used a 32-bit value in the 'reg' address, instead of a 36-bit address.

Signed-off-by: Timur Tabi <timur at freescale.com>
---
 arch/powerpc/cpu/mpc85xx/fdt.c |   48 ++++++++++++++++++++++++++++++++-------
 1 files changed, 39 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/cpu/mpc85xx/fdt.c b/arch/powerpc/cpu/mpc85xx/fdt.c
index 9d31568..2fcd8c3 100644
--- a/arch/powerpc/cpu/mpc85xx/fdt.c
+++ b/arch/powerpc/cpu/mpc85xx/fdt.c
@@ -677,6 +677,12 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 #define CCSR_VIRT_TO_PHYS(x) \
 	(CONFIG_SYS_CCSRBAR_PHYS + ((x) - CONFIG_SYS_CCSRBAR))
 
+static void msg(const char *name, uint64_t uaddr, uint64_t daddr)
+{
+	printf("Warning: U-Boot configured %s at address %llx,\n"
+	       "but the device tree has it at %llx\n", name, uaddr, daddr);
+}
+
 /*
  * Verify the device tree
  *
@@ -692,33 +698,32 @@ void ft_cpu_setup(void *blob, bd_t *bd)
  */
 int ft_verify_fdt(void *fdt)
 {
-	uint64_t ccsr = 0;
+	uint64_t addr = 0;
 	int aliases;
 	int off;
 
 	/* First check the CCSR base address */
 	off = fdt_node_offset_by_prop_value(fdt, -1, "device_type", "soc", 4);
 	if (off > 0)
-		ccsr = fdt_get_base_address(fdt, off);
+		addr = fdt_get_base_address(fdt, off);
 
-	if (!ccsr) {
+	if (!addr) {
 		printf("Warning: could not determine base CCSR address in "
 		       "device tree\n");
 		/* No point in checking anything else */
 		return 0;
 	}
 
-	if (ccsr != CONFIG_SYS_CCSRBAR_PHYS) {
-		printf("Warning: U-Boot configured CCSR at address %llx,\n"
-		       "but the device tree has it at %llx\n",
-		       (uint64_t) CONFIG_SYS_CCSRBAR_PHYS, ccsr);
+	if (addr != CONFIG_SYS_CCSRBAR_PHYS) {
+		msg("CCSR", CONFIG_SYS_CCSRBAR_PHYS, addr);
 		/* No point in checking anything else */
 		return 0;
 	}
 
 	/*
-	 * Get the 'aliases' node.  If there isn't one, then there's nothing
-	 * left to do.
+	 * Check some nodes via aliases.  We assume that U-Boot and the device
+	 * tree enumerate the devices equally.  E.g. the first serial port in
+	 * U-Boot is the same as "serial0" in the device tree.
 	 */
 	aliases = fdt_path_offset(fdt, "/aliases");
 	if (aliases > 0) {
@@ -735,5 +740,30 @@ int ft_verify_fdt(void *fdt)
 #endif
 	}
 
+	/*
+	 * The localbus node is typically a root node, even though the lbc
+	 * controller is part of CCSR.  If we were to put the lbc node under
+	 * the SOC node, then the 'ranges' property in the lbc node would
+	 * translate through the 'ranges' property of the parent SOC node, and
+	 * we don't want that.  Since it's a separate node, it's possible for
+	 * the 'reg' property to be wrong, so check it here.  For now, we
+	 * only check for "fsl,elbc" nodes.
+	 */
+#ifdef CONFIG_SYS_LBC_ADDR
+	off = fdt_node_offset_by_compatible(fdt, -1, "fsl,elbc");
+	if (off > 0) {
+		const u32 *reg = fdt_getprop(fdt, off, "reg", NULL);
+		if (reg) {
+			uint64_t uaddr = CCSR_VIRT_TO_PHYS(CONFIG_SYS_LBC_ADDR);
+
+			addr = fdt_translate_address(fdt, off, reg);
+			if (uaddr != addr) {
+				msg("the localbus", uaddr, addr);
+				return 0;
+			}
+		}
+	}
+#endif
+
 	return 1;
 }
-- 
1.7.3.4