MIPS: Loongson: Add Loongson-3A R3 basic support

Loongson-3A R3 is very similar to Loongson-3A R2.

All Loongson-3 CPU family:

Code-name       Brand-name       PRId
Loongson-3A R1  Loongson-3A1000  0x6305
Loongson-3A R2  Loongson-3A2000  0x6308
Loongson-3A R3  Loongson-3A3000  0x6309
Loongson-3B R1  Loongson-3B1000  0x6306
Loongson-3B R2  Loongson-3B1500  0x6307

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16585/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/cpu.h

@@ -248,6 +248,7 @@
 #define PRID_REV_LOONGSON3B_R1	0x0006
 #define PRID_REV_LOONGSON3B_R2	0x0007
 #define PRID_REV_LOONGSON3A_R2	0x0008
+#define PRID_REV_LOONGSON3A_R3	0x0009
 
 /*
  * Older processors used to encode processor version and revision in two

arch/mips/kernel/cpu-probe.c

@@ -1836,6 +1836,12 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
 			set_elf_platform(cpu, "loongson3a");
 			set_isa(c, MIPS_CPU_ISA_M64R2);
 			break;
+		case PRID_REV_LOONGSON3A_R3:
+			c->cputype = CPU_LOONGSON3;
+			__cpu_name[cpu] = "ICT Loongson-3";
+			set_elf_platform(cpu, "loongson3a");
+			set_isa(c, MIPS_CPU_ISA_M64R2);
+			break;
 		}
 
 		decode_configs(c);

arch/mips/loongson64/common/env.c

@@ -193,6 +193,7 @@ void __init prom_init_env(void)
 			break;
 		case PRID_REV_LOONGSON3A_R1:
 		case PRID_REV_LOONGSON3A_R2:
+		case PRID_REV_LOONGSON3A_R3:
 			cpu_clock_freq = 900000000;
 			break;
 		case PRID_REV_LOONGSON3B_R1:

arch/mips/loongson64/loongson-3/smp.c

@@ -503,7 +503,7 @@ static void loongson3a_r1_play_dead(int *state_addr)
 		: "a1");
 }
 
-static void loongson3a_r2_play_dead(int *state_addr)
+static void loongson3a_r2r3_play_dead(int *state_addr)
 {
 	register int val;
 	register long cpuid, core, node, count;
@@ -664,8 +664,9 @@ void play_dead(void)
 			(void *)CKSEG1ADDR((unsigned long)loongson3a_r1_play_dead);
 		break;
 	case PRID_REV_LOONGSON3A_R2:
+	case PRID_REV_LOONGSON3A_R3:
 		play_dead_at_ckseg1 =
-			(void *)CKSEG1ADDR((unsigned long)loongson3a_r2_play_dead);
+			(void *)CKSEG1ADDR((unsigned long)loongson3a_r2r3_play_dead);
 		break;
 	case PRID_REV_LOONGSON3B_R1:
 	case PRID_REV_LOONGSON3B_R2:

drivers/platform/mips/cpu_hwmon.c

@@ -17,14 +17,23 @@
  */
 int loongson3_cpu_temp(int cpu)
 {
-	u32 reg;
+	u32 reg, prid_rev;
 
 	reg = LOONGSON_CHIPTEMP(cpu);
-	if ((read_c0_prid() & PRID_REV_MASK) == PRID_REV_LOONGSON3A_R1)
+	prid_rev = read_c0_prid() & PRID_REV_MASK;
+	switch (prid_rev) {
+	case PRID_REV_LOONGSON3A_R1:
 		reg = (reg >> 8) & 0xff;
-	else
+		break;
+	case PRID_REV_LOONGSON3A_R2:
+	case PRID_REV_LOONGSON3B_R1:
+	case PRID_REV_LOONGSON3B_R2:
 		reg = ((reg >> 8) & 0xff) - 100;
-
+		break;
+	case PRID_REV_LOONGSON3A_R3:
+		reg = (reg & 0xffff)*731/0x4000 - 273;
+		break;
+	}
 	return (int)reg * 1000;
 }