x86: Correct problems in the microcode loading

There are several problems in the code. The device tree decode is incorrect
in ways that are masked due to a matching bug. Both are fixed. Also
microcode_read_rev() should be inline and called before the microcode is
written.

Note: microcode writing does not work correctly on ivybridge for me. Further
work is needed to resolve this. But this patch tidies up the existing code
so that will be easier.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/ivybridge/microcode_intel.c

@@ -50,17 +50,17 @@ static int microcode_decode_node(const void *blob, int node,
 	update->date_code = fdtdec_get_int(blob, node,
 					   "intel,date-code", 0);
 	update->processor_signature = fdtdec_get_int(blob, node,
-					"intel.processor-signature", 0);
+					"intel,processor-signature", 0);
 	update->checksum = fdtdec_get_int(blob, node, "intel,checksum", 0);
 	update->loader_revision = fdtdec_get_int(blob, node,
-						 "loader-revision", 0);
+						 "intel,loader-revision", 0);
 	update->processor_flags = fdtdec_get_int(blob, node,
-						 "processor-flags", 0);
+						 "intel,processor-flags", 0);
 
 	return 0;
 }
 
-static uint32_t microcode_read_rev(void)
+static inline uint32_t microcode_read_rev(void)
 {
 	/*
 	 * Some Intel CPUs can be very finicky about the CPUID sequence used.
@@ -116,6 +116,7 @@ int microcode_update_intel(void)
 {
 	struct microcode_update cpu, update;
 	const void *blob = gd->fdt_blob;
+	int skipped;
 	int count;
 	int node;
 	int ret;
@@ -123,12 +124,13 @@ int microcode_update_intel(void)
 	microcode_read_cpu(&cpu);
 	node = 0;
 	count = 0;
+	skipped = 0;
 	do {
 		node = fdtdec_next_compatible(blob, node,
 					      COMPAT_INTEL_MICROCODE);
 		if (node < 0) {
 			debug("%s: Found %d updates\n", __func__, count);
-			return count ? 0 : -ENOENT;
+			return count ? 0 : skipped ? -EEXIST : -ENOENT;
 		}
 
 		ret = microcode_decode_node(blob, node, &update);
@@ -137,12 +139,15 @@ int microcode_update_intel(void)
 			      ret);
 			return ret;
 		}
-		if (update.processor_signature == cpu.processor_signature &&
-		    (update.processor_flags & cpu.processor_flags)) {
-			debug("%s: Update already exists\n", __func__);
-			return -EEXIST;
+		if (!(update.processor_signature == cpu.processor_signature &&
+		      (update.processor_flags & cpu.processor_flags))) {
+			debug("%s: Skipping non-matching update, sig=%x, pf=%x\n",
+			      __func__, update.processor_signature,
+			      update.processor_flags);
+			skipped++;
+			continue;
 		}
-
+		ret = microcode_read_rev();
 		wrmsr(0x79, (ulong)update.data, 0);
 		debug("microcode: updated to revision 0x%x date=%04x-%02x-%02x\n",
 		      microcode_read_rev(), update.date_code & 0xffff,