ARCv2: boot log: refurbish HS core/release identification

HS core names and releases have so far been identified based solely on
IDENTIFY.ARCVER field. With the future HS releases this will not
be sufficient as same ARCVER 0x54 could be an HS38 or HS48.

So rewrite the code to use a new BCR to identify the cores properly.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/arcregs.h

@@ -313,7 +313,7 @@ struct cpuinfo_arc {
 	struct cpuinfo_arc_bpu bpu;
 	struct bcr_identity core;
 	struct bcr_isa_arcv2 isa;
-	const char *details, *name;
+	const char *release, *name;
 	unsigned int vec_base;
 	struct cpuinfo_arc_ccm iccm, dccm;
 	struct {

arch/arc/kernel/setup.c

@@ -45,7 +45,8 @@ struct task_struct *_current_task[NR_CPUS];	/* For stack switching */
 
 struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
 
-static const struct id_to_str arc_cpu_rel[] = {
+static const struct id_to_str arc_legacy_rel[] = {
+	/* ID.ARCVER,	Release */
 #ifdef CONFIG_ISA_ARCOMPACT
 	{ 0x34, 	"R4.10"},
 	{ 0x35, 	"R4.11"},
@@ -53,21 +54,15 @@ static const struct id_to_str arc_cpu_rel[] = {
 	{ 0x51, 	"R2.0" },
 	{ 0x52, 	"R2.1" },
 	{ 0x53,		"R3.0" },
-	{ 0x54, "R3.10a" },
 #endif
 	{ 0x00,		NULL   }
 };
 
-static const struct id_to_str arc_cpu_nm[] = {
-#ifdef CONFIG_ISA_ARCOMPACT
-	{ 0x20, "ARC 600"   },
-	{ 0x30, "ARC 770"   },  /* 750 identified seperately */
-#else
-	{ 0x40, "ARC EM"  },
-	{ 0x50, "ARC HS38"  },
-	{ 0x54, "ARC HS48"  },
-#endif
-	{ 0x00, "Unknown"   }
+static const struct id_to_str arc_cpu_rel[] = {
+	/* UARCH.MAJOR,	Release */
+	{  0,		"R3.10a"},
+	{  1,		"R3.50a"},
+	{  0xFF,	NULL   }
 };
 
 static void read_decode_ccm_bcr(struct cpuinfo_arc *cpu)
@@ -117,31 +112,72 @@ static void read_decode_ccm_bcr(struct cpuinfo_arc *cpu)
 	}
 }
 
-static void read_arc_build_cfg_regs(void)
+static void decode_arc_core(struct cpuinfo_arc *cpu)
 {
-	struct bcr_timer timer;
-	struct bcr_generic bcr;
-	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
+	struct bcr_uarch_build_arcv2 uarch;
 	const struct id_to_str *tbl;
-	struct bcr_isa_arcv2 isa;
-	struct bcr_actionpoint ap;
 
-	FIX_PTR(cpu);
+	/*
+	 * Up until (including) the first core4 release (0x54) things were
+	 * simple: AUX IDENTITY.ARCVER was sufficient to identify arc family
+	 * and release: 0x50 to 0x53 was HS38, 0x54 was HS48 (dual issue)
+	 */
 
-	READ_BCR(AUX_IDENTITY, cpu->core);
+	if (cpu->core.family < 0x54) { /* includes arc700 */
 
-	for (tbl = &arc_cpu_rel[0]; tbl->id != 0; tbl++) {
+		for (tbl = &arc_legacy_rel[0]; tbl->id != 0; tbl++) {
 			if (cpu->core.family == tbl->id) {
-			cpu->details = tbl->str;
+				cpu->release = tbl->str;
 				break;
 			}
 		}
 
-	for (tbl = &arc_cpu_nm[0]; tbl->id != 0; tbl++) {
-		if ((cpu->core.family & 0xF4) == tbl->id)
+		if (is_isa_arcompact())
+			cpu->name = "ARC700";
+		else if (tbl->str)
+			cpu->name = "HS38";
+		else
+			cpu->name = cpu->release = "Unknown";
+
+		return;
+	}
+
+	/*
+	 * However the subsequent HS release (same 0x54) allow HS38 or HS48
+	 * configurations and encode this info in a different BCR.
+	 * The BCR was introduced in 0x54 so can't be read unconditionally.
+	 */
+
+	READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
+
+	if (uarch.prod == 4) {
+		cpu->name = "HS48";
+		cpu->extn.dual = 1;
+
+	} else {
+		cpu->name = "HS38";
+	}
+
+	for (tbl = &arc_cpu_rel[0]; tbl->id != 0xFF; tbl++) {
+		if (uarch.maj == tbl->id) {
+			cpu->release = tbl->str;
 			break;
 		}
-	cpu->name = tbl->str;
+	}
+}
+
+static void read_arc_build_cfg_regs(void)
+{
+	struct bcr_timer timer;
+	struct bcr_generic bcr;
+	struct cpuinfo_arc *cpu = &cpuinfo_arc700[smp_processor_id()];
+	struct bcr_isa_arcv2 isa;
+	struct bcr_actionpoint ap;
+
+	FIX_PTR(cpu);
+
+	READ_BCR(AUX_IDENTITY, cpu->core);
+	decode_arc_core(cpu);
 
 	READ_BCR(ARC_REG_TIMERS_BCR, timer);
 	cpu->extn.timer0 = timer.t0;
@@ -199,30 +235,12 @@ static void read_arc_build_cfg_regs(void)
 		cpu->bpu.num_pred = 2048 << bpu.pte;
 		cpu->bpu.ret_stk = 4 << bpu.rse;
 
-		if (cpu->core.family >= 0x54) {
-
-			struct bcr_uarch_build_arcv2 uarch;
-
-			/*
-			 * The first 0x54 core (uarch maj:min 0:1 or 0:2) was
-			 * dual issue only (HS4x). But next uarch rev (1:0)
-			 * allows it be configured for single issue (HS3x)
-			 * Ensure we fiddle with dual issue only on HS4x
-			 */
-			READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch);
-
-			if (uarch.prod == 4) {
+		/* if dual issue hardware, is it enabled ? */
+		if (cpu->extn.dual) {
 			unsigned int exec_ctrl;
 
-				/* dual issue hardware always present */
-				cpu->extn.dual = 1;
-
 			READ_BCR(AUX_EXEC_CTRL, exec_ctrl);
-
-				/* dual issue hardware enabled ? */
 			cpu->extn.dual_enb = !(exec_ctrl & 1);
-
-			}
 		}
 	}
 
@@ -273,7 +291,7 @@ static char *arc_cpu_mumbojumbo(int cpu_id, char *buf, int len)
 		       core->family, core->cpu_id, core->chip_id);
 
 	n += scnprintf(buf + n, len - n, "processor [%d]\t: %s %s (%s ISA) %s%s%s\n",
-		       cpu_id, cpu->name, cpu->details,
+		       cpu_id, cpu->name, cpu->release,
 		       is_isa_arcompact() ? "ARCompact" : "ARCv2",
 		       IS_AVAIL1(cpu->isa.be, "[Big-Endian]"),
 		       IS_AVAIL3(cpu->extn.dual, cpu->extn.dual_enb, " Dual-Issue "));