[Skiboot] [PATCH 2/8] gard: Set chip generation based on PVR

[Oliver O'Halloran]

Currently we assume that this tool is being used on a P8 system by
default and allow the user to override this behaviour using the -8 and
-9 command line arguments. When running on the host we can use the
PVR to guess what chip generation so do that.

This also changes the default behaviour to assume that the host is a P9
when running on an ARM system. This tool didn't even work when compiled
for ARM until recently and the OpenBMC vPNOR hack that we have currently
is broken for P9 systems that don't use vPNOR (Zaius and Romulus).

Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
---
 external/gard/gard.c | 52 ++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 42 insertions(+), 10 deletions(-)

diff --git a/external/gard/gard.c b/external/gard/gard.c
index c280bbf710ba..c70fa2a3ccfd 100644
--- a/external/gard/gard.c
+++ b/external/gard/gard.c
@@ -159,6 +159,45 @@ static void set_chip_gen(const struct chip_unit_desc *c)
 	}
 }
 
+#ifdef __powerpc64__
+static void guess_chip_gen(void)
+{
+	/*
+	 * Guesstimate what chip generation based on the PVR if we're running
+	 * on ppc64.
+	 */
+	uint32_t pvr;
+
+	/* grab the chip type from the PVR SPR */
+	asm ("mfspr  %0,0x11f" : "=r" (pvr));
+
+	switch (pvr >> 16) {
+	case 0x004b: /* murano */
+	case 0x004c: /* naples */
+	case 0x004d: /* venice */
+		set_chip_gen(p8_chip_units);
+		return;
+
+	case 0x004e: /* nimbus */
+		set_chip_gen(p9_chip_units);
+		return;
+
+	default:
+		fprintf(stderr, "Unsupported processor (pvr %#x)! Set the processor generation manually with -8 or -9\n", pvr);
+		exit(1);
+	}
+}
+#else
+static void guess_chip_gen(void)
+{
+#ifdef ASSUME_P8
+	set_chip_gen(p8_chip_units);
+#else
+	set_chip_gen(p9_chip_units);
+#endif
+}
+#endif
+
 static const char *target_type_to_str(int type)
 {
 	int i;
@@ -874,15 +913,6 @@ int main(int argc, char **argv)
 	argv += optind;
 	action = argv[0];
 
-	/* assume a P8 if we haven't been given any */
-	if (!chip_units) {
-#ifdef ASSUME_P9
-		set_chip_gen(p9_chip_units);
-#else
-		set_chip_gen(p8_chip_units);
-#endif
-	}
-
 #ifdef __arm__
 	/*
 	 * HACK: Look for a vPNOR GUARD file if we haven't been given anything
@@ -903,7 +933,6 @@ int main(int argc, char **argv)
 			/* BUG: This ignores the command line settings */
 			part = true;
 			ecc = true;
-			set_chip_gen(p9_chip_units);
 		} else if (!stat(VPNOR_GARD_DIR, &buf)) {
 			printf(VPNOR_GARD_FILE" is missing. Nothing to do\n");
 			return 0;
@@ -911,6 +940,9 @@ int main(int argc, char **argv)
 	}
 #endif
 
+	if (!chip_units)
+		guess_chip_gen();
+
 	/*
 	 * Force libflash to do flash accesses via the MTD. Direct mode is
 	 * generally unsafe since it fiddles with the flash controller state
-- 
2.9.5