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>

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>
Simon Glass
1 parent cf29e3e303
Showing 1 changed file with 15 additions and 10 deletions Side-by-side Diff
arch/x86/cpu/ivybridge/microcode_intel.c
@@ -50,17 +50,17 @@
 	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 @@
 {
 	struct microcode_update cpu, update;
 	const void *blob = gd->fdt_blob;
+	int skipped;
 	int count;
 	int node;
 	int ret;
  
@@ -123,12 +124,13 @@
 	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 @@
 			      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,
...	...	@@ -50,17 +50,17 @@
50	50	update->date_code = fdtdec_get_int(blob, node,
51	51	"intel,date-code", 0);
52	52	update->processor_signature = fdtdec_get_int(blob, node,
53		- "intel.processor-signature", 0);
	53	+ "intel,processor-signature", 0);
54	54	update->checksum = fdtdec_get_int(blob, node, "intel,checksum", 0);
55	55	update->loader_revision = fdtdec_get_int(blob, node,
56		- "loader-revision", 0);
	56	+ "intel,loader-revision", 0);
57	57	update->processor_flags = fdtdec_get_int(blob, node,
58		- "processor-flags", 0);
	58	+ "intel,processor-flags", 0);
59	59
60	60	return 0;
61	61	}
62	62
63		-static uint32_t microcode_read_rev(void)
	63	+static inline uint32_t microcode_read_rev(void)
64	64	{
65	65	/*
66	66	* Some Intel CPUs can be very finicky about the CPUID sequence used.
...	...	@@ -116,6 +116,7 @@
116	116	{
117	117	struct microcode_update cpu, update;
118	118	const void *blob = gd->fdt_blob;
	119	+ int skipped;
119	120	int count;
120	121	int node;
121	122	int ret;
122	123
...	...	@@ -123,12 +124,13 @@
123	124	microcode_read_cpu(&cpu);
124	125	node = 0;
125	126	count = 0;
	127	+ skipped = 0;
126	128	do {
127	129	node = fdtdec_next_compatible(blob, node,
128	130	COMPAT_INTEL_MICROCODE);
129	131	if (node < 0) {
130	132	debug("%s: Found %d updates\n", __func__, count);
131		- return count ? 0 : -ENOENT;
	133	+ return count ? 0 : skipped ? -EEXIST : -ENOENT;
132	134	}
133	135
134	136	ret = microcode_decode_node(blob, node, &update);
135	137
...	...	@@ -137,12 +139,15 @@
137	139	ret);
138	140	return ret;
139	141	}
140		- if (update.processor_signature == cpu.processor_signature &&
141		- (update.processor_flags & cpu.processor_flags)) {
142		- debug("%s: Update already exists\n", __func__);
143		- return -EEXIST;
	142	+ if (!(update.processor_signature == cpu.processor_signature &&
	143	+ (update.processor_flags & cpu.processor_flags))) {
	144	+ debug("%s: Skipping non-matching update, sig=%x, pf=%x\n",
	145	+ __func__, update.processor_signature,
	146	+ update.processor_flags);
	147	+ skipped++;
	148	+ continue;
144	149	}
145		-
	150	+ ret = microcode_read_rev();
146	151	wrmsr(0x79, (ulong)update.data, 0);
147	152	debug("microcode: updated to revision 0x%x date=%04x-%02x-%02x\n",
148	153	microcode_read_rev(), update.date_code & 0xffff,