[PATCH v3,1/5] MIPS: Add support for the 1074K core.

["Steven J. Hill" <sjhill@xxxxxxxx>]

From: "Steven J. Hill" <sjhill@xxxxxxxx>

This patch adds support for detecting and using 1074K cores.

Signed-off-by: Steven J. Hill <sjhill@xxxxxxxx>
---
 arch/mips/include/asm/cpu.h  |    1 +
 arch/mips/kernel/cpu-probe.c |    4 ++++
 arch/mips/mm/c-r4k.c         |   20 +++++++++++++++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index f9fa2a4..9f8feeb 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -94,6 +94,7 @@
 #define PRID_IMP_24KE		0x9600
 #define PRID_IMP_74K		0x9700
 #define PRID_IMP_1004K		0x9900
+#define PRID_IMP_1074K		0x9a00
 
 /*
  * These are the PRID's for when 23:16 == PRID_COMP_SIBYTE
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index 5099201..4b5c7d6 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -835,6 +835,10 @@ static inline void cpu_probe_mips(struct cpuinfo_mips *c, unsigned int cpu)
 		c->cputype = CPU_1004K;
 		__cpu_name[cpu] = "MIPS 1004Kc";
 		break;
+	case PRID_IMP_1074K:
+		c->cputype = CPU_74K;
+		__cpu_name[cpu] = "MIPS 1074Kc";
+		break;
 	}
 
 	spram_config();
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index bda8eb2..c729828 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1051,9 +1051,26 @@ static void __cpuinit probe_pcache(void)
 	case CPU_R14000:
 		break;
 
+	case CPU_74K:
+		/*
+		 * Early versions of the 74k do not update
+		 * the cache tags on a vtag miss/ptag hit
+		 * which can occur in the case of KSEG0/KUSEG aliases
+		 * In this case it is better to treat the cache as always
+		 * having aliases
+		 */
+		if ((c->processor_id & 0xff) <= PRID_REV_ENCODE_332(2, 4, 0))
+			c->dcache.flags |= MIPS_CACHE_VTAG;
+		if ((c->processor_id & 0xff) == PRID_REV_ENCODE_332(2, 4, 0))
+			write_c0_config6(read_c0_config6() | MIPS_CONF6_SYND);
+		if (((c->processor_id & 0xff00) == PRID_IMP_1074K) &&
+		   ((c->processor_id & 0xff) <= PRID_REV_ENCODE_332(1, 1, 0))) {
+			c->dcache.flags |= MIPS_CACHE_VTAG;
+			write_c0_config6(read_c0_config6() | MIPS_CONF6_SYND);
+		}
+		/* fall through */
 	case CPU_24K:
 	case CPU_34K:
-	case CPU_74K:
 	case CPU_1004K:
 		if ((read_c0_config7() & (1 << 16))) {
 			/* effectively physically indexed dcache,
@@ -1061,6 +1078,7 @@ static void __cpuinit probe_pcache(void)
 			c->dcache.flags |= MIPS_CACHE_PINDEX;
 			break;
 		}
+		/* fall through */
 	default:
 		if (c->dcache.waysize > PAGE_SIZE)
 			c->dcache.flags |= MIPS_CACHE_ALIASES;
-- 
1.7.10