aarch64: simplify mode and state handling

Aarch32 and Aarch64 modes don't conflict in CPSR, no need to deconflict
ARMv7-M profile modes either.


Change-Id: I4c437dfa657f9e8a1da3687bc9f21435384b7881
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Reviewed-on: http://openocd.zylin.com/4144
Tested-by: jenkins
Reviewed-by: Yao Qi <qiyaoltc@gmail.com>
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>

src/target/arm.h

@@ -66,14 +66,13 @@ enum arm_mode {
 	ARM_MODE_USER_THREAD = 1,
 	ARM_MODE_HANDLER = 2,
 
-	/* shift left 4 bits for armv8 64 */
-	ARMV8_64_EL0T = 0x0F,
-	ARMV8_64_EL1T = 0x4F,
-	ARMV8_64_EL1H = 0x5F,
-	ARMV8_64_EL2T = 0x8F,
-	ARMV8_64_EL2H = 0x9F,
-	ARMV8_64_EL3T = 0xCF,
-	ARMV8_64_EL3H = 0xDF,
+	ARMV8_64_EL0T = 0x0,
+	ARMV8_64_EL1T = 0x4,
+	ARMV8_64_EL1H = 0x5,
+	ARMV8_64_EL2T = 0x8,
+	ARMV8_64_EL2H = 0x9,
+	ARMV8_64_EL3T = 0xC,
+	ARMV8_64_EL3H = 0xD,
 
 	ARM_MODE_ANY = -1
 };

src/target/armv8.c

@@ -45,8 +45,6 @@ static const struct {
 	const char *name;
 	unsigned psr;
 } armv8_mode_data[] = {
-	/* These special modes are currently only supported
-	 * by ARMv6M and ARMv7M profiles */
 	{
 		.name = "USR",
 		.psr = ARM_MODE_USR,
@@ -112,48 +110,6 @@ const char *armv8_mode_name(unsigned psr_mode)
 	return "UNRECOGNIZED";
 }
 
-int armv8_mode_to_number(enum arm_mode mode)
-{
-	switch (mode) {
-		case ARM_MODE_ANY:
-		/* map MODE_ANY to user mode */
-		case ARM_MODE_USR:
-			return 0;
-		case ARM_MODE_FIQ:
-			return 1;
-		case ARM_MODE_IRQ:
-			return 2;
-		case ARM_MODE_SVC:
-			return 3;
-		case ARM_MODE_ABT:
-			return 4;
-		case ARM_MODE_UND:
-			return 5;
-		case ARM_MODE_SYS:
-			return 6;
-		case ARM_MODE_MON:
-			return 7;
-		case ARMV8_64_EL0T:
-			return 8;
-		case ARMV8_64_EL1T:
-			return 9;
-		case ARMV8_64_EL1H:
-			return 10;
-		case ARMV8_64_EL2T:
-			return 11;
-		case ARMV8_64_EL2H:
-			return 12;
-		case ARMV8_64_EL3T:
-			return 13;
-		case ARMV8_64_EL3H:
-			return 14;
-
-		default:
-			LOG_ERROR("invalid mode value encountered %d", mode);
-			return -1;
-	}
-}
-
 static int armv8_read_reg(struct armv8_common *armv8, int regnum, uint64_t *regval)
 {
 	struct arm_dpm *dpm = &armv8->dpm;
@@ -533,9 +489,8 @@ void armv8_set_cpsr(struct arm *arm, uint32_t cpsr)
 	/* Older ARMs won't have the J bit */
 	enum arm_state state = 0xFF;
 
-	if (((cpsr & 0x10) >> 4) == 0) {
-		state = ARM_STATE_AARCH64;
-	} else {
+	if ((cpsr & 0x10) != 0) {
+		/* Aarch32 state */
 		if (cpsr & (1 << 5)) {	/* T */
 			if (cpsr & (1 << 24)) { /* J */
 				LOG_WARNING("ThumbEE -- incomplete support");
@@ -549,12 +504,13 @@ void armv8_set_cpsr(struct arm *arm, uint32_t cpsr)
 			} else
 				state = ARM_STATE_ARM;
 		}
+	} else {
+		/* Aarch64 state */
+		state = ARM_STATE_AARCH64;
 	}
+
 	arm->core_state = state;
-	if (arm->core_state == ARM_STATE_AARCH64)
-		arm->core_mode = (mode << 4) | 0xf;
-	else
-		arm->core_mode = mode;
+	arm->core_mode = mode;
 
 	LOG_DEBUG("set CPSR %#8.8x: %s mode, %s state", (unsigned) cpsr,
 		armv8_mode_name(arm->core_mode),

src/target/armv8.h

@@ -270,7 +270,7 @@ static inline unsigned int armv8_curel_from_core_mode(enum arm_mode core_mode)
 		return 3;
 	/* all Aarch64 modes */
 	default:
-		return (core_mode >> 6) & 3;
+		return (core_mode >> 2) & 3;
 	}
 }
 

src/target/armv8_dpm.c

@@ -561,12 +561,7 @@ int armv8_dpm_modeswitch(struct arm_dpm *dpm, enum arm_mode mode)
 
 	} else {
 		LOG_DEBUG("setting mode 0x%"PRIx32, mode);
-
-		/* else force to the specified mode */
-		if (is_arm_mode(mode))
-			cpsr = mode;
-		else
-			cpsr = mode >> 4;
+		cpsr = mode;
 	}
 
 	switch (cpsr & 0x1f) {