[PATCH v2 1/8] MIPS: Loongson: Add basic Loongson-1A CPU support

[Binbin Zhou <zhoubb@lemote.com>]

The Loongson 1A is similar with Loongson 1B, which is a 32-bit SoC.
It implements the MIPS32 release 2 instruction set.

They share the same PRID, so we rewrite the PRID_REV_LOONGSON1B to
PRID_REV_LOONGSON1A_1B, and use their CPU macros to distinguish.

Signed-off-by: Chunbo Cui <cuicb@lemote.com>
Signed-off-by: Binbin Zhou <zhoubb@lemote.com>
Signed-off-by: Huacai Chen <chenhc@lemote.com>
---
 arch/mips/include/asm/cpu-type.h    | 3 ++-
 arch/mips/include/asm/cpu.h         | 2 +-
 arch/mips/kernel/cpu-probe.c        | 6 +++++-
 arch/mips/loongson32/Platform       | 1 +
 arch/mips/loongson32/common/setup.c | 6 +++++-
 arch/mips/mm/c-r4k.c                | 7 +++++++
 6 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/cpu-type.h b/arch/mips/include/asm/cpu-type.h
index d41e8e2..b05908c 100644
--- a/arch/mips/include/asm/cpu-type.h
+++ b/arch/mips/include/asm/cpu-type.h
@@ -24,7 +24,8 @@ static inline int __pure __get_cpu_type(const int cpu_type)
 	case CPU_LOONGSON3:
 #endif
 
-#ifdef CONFIG_SYS_HAS_CPU_LOONGSON1B
+#if defined(CONFIG_SYS_HAS_CPU_LOONGSON1A) || \
+    defined(CONFIG_SYS_HAS_CPU_LOONGSON1B)
 	case CPU_LOONGSON1:
 #endif
 
diff --git a/arch/mips/include/asm/cpu.h b/arch/mips/include/asm/cpu.h
index e46e406..a868441 100644
--- a/arch/mips/include/asm/cpu.h
+++ b/arch/mips/include/asm/cpu.h
@@ -233,7 +233,7 @@
 #define PRID_REV_VR4181A	0x0070	/* Same as VR4122 */
 #define PRID_REV_VR4130		0x0080
 #define PRID_REV_34K_V1_0_2	0x0022
-#define PRID_REV_LOONGSON1B	0x0020
+#define PRID_REV_LOONGSON1A_1B	0x0020
 #define PRID_REV_LOONGSON2E	0x0002
 #define PRID_REV_LOONGSON2F	0x0003
 #define PRID_REV_LOONGSON3A	0x0005
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
index dbe0792..fa5c33e 100644
--- a/arch/mips/kernel/cpu-probe.c
+++ b/arch/mips/kernel/cpu-probe.c
@@ -1006,8 +1006,12 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu)
 		c->cputype = CPU_LOONGSON1;
 
 		switch (c->processor_id & PRID_REV_MASK) {
-		case PRID_REV_LOONGSON1B:
+		case PRID_REV_LOONGSON1A_1B:
+#ifdef CONFIG_CPU_LOONGSON1A
+			__cpu_name[cpu] = "Loongson 1A";
+#else
 			__cpu_name[cpu] = "Loongson 1B";
+#endif
 			break;
 		}
 
diff --git a/arch/mips/loongson32/Platform b/arch/mips/loongson32/Platform
index ebb6dc2..e114c85 100644
--- a/arch/mips/loongson32/Platform
+++ b/arch/mips/loongson32/Platform
@@ -4,4 +4,5 @@ cflags-$(CONFIG_CPU_LOONGSON1)	+= \
 
 platform-$(CONFIG_MACH_LOONGSON32)	+= loongson32/
 cflags-$(CONFIG_MACH_LOONGSON32)	+= -I$(srctree)/arch/mips/include/asm/mach-loongson32
+load-$(CONFIG_LOONGSON1_LS1A)		+= 0xffffffff80200000
 load-$(CONFIG_LOONGSON1_LS1B)		+= 0xffffffff80100000
diff --git a/arch/mips/loongson32/common/setup.c b/arch/mips/loongson32/common/setup.c
index 62f41af..c3d2036 100644
--- a/arch/mips/loongson32/common/setup.c
+++ b/arch/mips/loongson32/common/setup.c
@@ -21,8 +21,12 @@ const char *get_system_type(void)
 	unsigned int processor_id = (&current_cpu_data)->processor_id;
 
 	switch (processor_id & PRID_REV_MASK) {
-	case PRID_REV_LOONGSON1B:
+	case PRID_REV_LOONGSON1A_1B:
+#ifdef CONFIG_CPU_LOONGSON1A
+		return "LOONGSON LS1A";
+#else
 		return "LOONGSON LS1B";
+#endif
 	default:
 		return "LOONGSON (unknown)";
 	}
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 7f660dc..cec179f 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1277,6 +1277,13 @@ static void probe_pcache(void)
 			c->dcache.flags |= MIPS_CACHE_PINDEX;
 			break;
 		}
+	case CPU_LOONGSON1:
+		if ((read_c0_config7() & (1 << 16))) {
+			/* effectively physically indexed dcache,
+			   thus no virtual aliases. */
+			c->dcache.flags |= MIPS_CACHE_PINDEX;
+			break;
+		}
 	default:
 		if (has_74k_erratum || c->dcache.waysize > PAGE_SIZE)
 			c->dcache.flags |= MIPS_CACHE_ALIASES;
-- 
1.9.0