target/riscv: decode DMI scans in batch access

This allows to merge the implementation in `batch.c` with the one in
`riscv-013.c`.

Change-Id: Ic3821a9ce2d75a7c6e618074679595ddefb14cfc
Signed-off-by: Evgeniy Naydanov <evgeniy.naydanov@syntacore.com>

src/target/riscv/batch.c

@@ -16,8 +16,6 @@
 /* Reserve extra room in the batch (needed for the last NOP operation) */
 #define BATCH_RESERVED_SCANS 1
 
-static void dump_field(int idle, const struct scan_field *field);
-
 struct riscv_batch *riscv_batch_alloc(struct target *target, size_t scans, size_t idle)
 {
 	scans += BATCH_RESERVED_SCANS;
@@ -128,7 +126,8 @@ int riscv_batch_run(struct riscv_batch *batch)
 	}
 
 	for (size_t i = 0; i < batch->used_scans; ++i)
-		dump_field(batch->idle_count, batch->fields + i);
+		riscv_decode_dmi_scan(batch->target, batch->idle_count, batch->fields + i,
+				/*discard_in*/ false);
 
 	return ERROR_OK;
 }
@@ -200,38 +199,6 @@ void riscv_batch_add_nop(struct riscv_batch *batch)
 	batch->used_scans++;
 }
 
-static void dump_field(int idle, const struct scan_field *field)
-{
-	static const char * const op_string[] = {"-", "r", "w", "?"};
-	static const char * const status_string[] = {"+", "?", "F", "b"};
-
-	if (debug_level < LOG_LVL_DEBUG)
-		return;
-
-	assert(field->out_value);
-	uint64_t out = buf_get_u64(field->out_value, 0, field->num_bits);
-	unsigned int out_op = get_field(out, DTM_DMI_OP);
-	unsigned int out_data = get_field(out, DTM_DMI_DATA);
-	unsigned int out_address = out >> DTM_DMI_ADDRESS_OFFSET;
-
-	if (field->in_value) {
-		uint64_t in = buf_get_u64(field->in_value, 0, field->num_bits);
-		unsigned int in_op = get_field(in, DTM_DMI_OP);
-		unsigned int in_data = get_field(in, DTM_DMI_DATA);
-		unsigned int in_address = in >> DTM_DMI_ADDRESS_OFFSET;
-
-		log_printf_lf(LOG_LVL_DEBUG,
-				__FILE__, __LINE__, __func__,
-				"%db %s %08x @%02x -> %s %08x @%02x; %di",
-				field->num_bits, op_string[out_op], out_data, out_address,
-				status_string[in_op], in_data, in_address, idle);
-	} else {
-		log_printf_lf(LOG_LVL_DEBUG,
-				__FILE__, __LINE__, __func__, "%db %s %08x @%02x -> ?; %di",
-				field->num_bits, op_string[out_op], out_data, out_address, idle);
-	}
-}
-
 size_t riscv_batch_available_scans(struct riscv_batch *batch)
 {
 	assert(batch->allocated_scans >= (batch->used_scans + BATCH_RESERVED_SCANS));

src/target/riscv/batch.h

@@ -78,4 +78,10 @@ size_t riscv_batch_available_scans(struct riscv_batch *batch);
 /* Return true iff the last scan in the batch returned DMI_OP_BUSY. */
 bool riscv_batch_dmi_busy_encountered(const struct riscv_batch *batch);
 
+/* TODO: The function is defined in `riscv-013.c`. This is done to reduce the
+ * diff of the commit. The intention is to move the function definition to
+ * a separate module (e.g. `riscv013-jtag-dtm.c/h`) in another commit. */
+void riscv_decode_dmi_scan(const struct target *target, int idle, const struct scan_field *field,
+		bool discard_in);
+
 #endif

src/target/riscv/riscv-013.c

@@ -363,10 +363,10 @@ static uint32_t set_dmcontrol_hartsel(uint32_t initial, int hart_index)
 	return initial;
 }
 
-static unsigned int decode_dm(char *text, unsigned int address, unsigned int data)
+static unsigned int decode_dmi(const struct target *target, char *text, uint32_t address, uint32_t data)
 {
 	static const struct {
-		unsigned int address;
+		uint32_t address;
 		enum riscv_debug_reg_ordinal ordinal;
 	} description[] = {
 		{DM_DMCONTROL, DM_DMCONTROL_ORDINAL},
@@ -377,7 +377,7 @@ static unsigned int decode_dm(char *text, unsigned int address, unsigned int dat
 	};
 
 	for (unsigned i = 0; i < ARRAY_SIZE(description); i++) {
-		if (description[i].address == address) {
+		if (riscv_get_dmi_address(target, description[i].address) == address) {
 			const riscv_debug_reg_ctx_t context = {
 				.XLEN = { .value = 0, .is_set = false },
 				.DXLEN = { .value = 0, .is_set = false },
@@ -392,19 +392,7 @@ static unsigned int decode_dm(char *text, unsigned int address, unsigned int dat
 	return 0;
 }
 
-static unsigned int decode_dmi(struct target *target, char *text, unsigned int address,
+void riscv_decode_dmi_scan(const struct target *target, int idle, const struct scan_field *field, bool discard_in)
-		unsigned int data)
-{
-	dm013_info_t *dm = get_dm(target);
-	if (!dm) {
-		if (text)
-			text[0] = '\0';
-		return 0;
-	}
-	return decode_dm(text, address - dm->base, data);
-}
-
-static void dump_field(struct target *target, int idle, const struct scan_field *field, bool discard_in)
 {
 	static const char * const op_string[] = {"-", "r", "w", "?"};
 	static const char * const status_string[] = {"+", "?", "F", "b"};
@@ -412,32 +400,42 @@ static void dump_field(struct target *target, int idle, const struct scan_field
 	if (debug_level < LOG_LVL_DEBUG)
 		return;
 
-	uint64_t out = buf_get_u64(field->out_value, 0, field->num_bits);
+	assert(field->out_value);
-	unsigned int out_op = get_field(out, DTM_DMI_OP);
+	const uint64_t out = buf_get_u64(field->out_value, 0, field->num_bits);
-	unsigned int out_data = get_field(out, DTM_DMI_DATA);
+	const unsigned int out_op = get_field(out, DTM_DMI_OP);
-	unsigned int out_address = out >> DTM_DMI_ADDRESS_OFFSET;
+	const uint32_t out_data = get_field(out, DTM_DMI_DATA);
+	const uint32_t out_address = out >> DTM_DMI_ADDRESS_OFFSET;
 
-	uint64_t in = buf_get_u64(field->in_value, 0, field->num_bits);
+	if (field->in_value) {
-	unsigned int in_op = get_field(in, DTM_DMI_OP);
+		const uint64_t in = buf_get_u64(field->in_value, 0, field->num_bits);
-	unsigned int in_data = get_field(in, DTM_DMI_DATA);
+		const unsigned int in_op = get_field(in, DTM_DMI_OP);
-	unsigned int in_address = in >> DTM_DMI_ADDRESS_OFFSET;
+		const uint32_t in_data = get_field(in, DTM_DMI_DATA);
+		const uint32_t in_address = in >> DTM_DMI_ADDRESS_OFFSET;
 
-	log_printf_lf(LOG_LVL_DEBUG, __FILE__, __LINE__, __func__,
+		LOG_DEBUG("%db %s %08" PRIx32 " @%02" PRIx32 " -> %s %08" PRIx32 " @%02" PRIx32 "; %di",
-			"%db %s %08x @%02x -> %s %08x @%02x; %di",
+				field->num_bits, op_string[out_op], out_data, out_address,
-			field->num_bits, op_string[out_op], out_data, out_address,
+				status_string[in_op], in_data, in_address, idle);
-			status_string[in_op], in_data, in_address, idle);
 
+		if (!discard_in && in_op == DTM_DMI_OP_SUCCESS) {
+			char in_decoded[decode_dmi(target, NULL, in_address, in_data) + 1];
+			decode_dmi(target, in_decoded, in_address, in_data);
+			/* FIXME: The current code assumes that the hardware
+			 * provides the read address in the dmi.address field
+			 * when returning the dmi.data. That is however not
+			 * required by the spec, and therefore not guaranteed.
+			 * See https://github.com/riscv-collab/riscv-openocd/issues/1043
+			 */
+			LOG_DEBUG("read: %s", in_decoded);
+		}
+	} else {
+		LOG_DEBUG("%db %s %08" PRIx32 " @%02" PRIx32 " -> ?; %di",
+				field->num_bits, op_string[out_op], out_data, out_address,
+				idle);
+	}
 	if (out_op == DTM_DMI_OP_WRITE) {
 		char out_decoded[decode_dmi(target, NULL, out_address, out_data) + 1];
 		decode_dmi(target, out_decoded, out_address, out_data);
-		log_printf_lf(LOG_LVL_DEBUG, __FILE__, __LINE__, __func__,
+		LOG_DEBUG("write: %s", out_decoded);
-				"write: %s", out_decoded);
-	}
-	if (!discard_in && in_op == DTM_DMI_OP_SUCCESS) {
-		char in_decoded[decode_dmi(target, NULL, in_address, in_data) + 1];
-		decode_dmi(target, in_decoded, in_address, in_data);
-		log_printf_lf(LOG_LVL_DEBUG, __FILE__, __LINE__, __func__,
-				"read: %s", in_decoded);
 	}
 }
 
@@ -578,7 +576,7 @@ static dmi_status_t dmi_scan(struct target *target, uint32_t *address_in,
 
 	if (address_in)
 		*address_in = buf_get_u32(in, DTM_DMI_ADDRESS_OFFSET, info->abits);
-	dump_field(target, idle_count, &field, /*discard_in*/ !data_in);
+	riscv_decode_dmi_scan(target, idle_count, &field, /*discard_in*/ !data_in);
 	return buf_get_u32(in, DTM_DMI_OP_OFFSET, DTM_DMI_OP_LENGTH);
 }
 

src/target/riscv/riscv.c

@@ -3712,7 +3712,7 @@ COMMAND_HANDLER(riscv_authdata_write)
 	return r->authdata_write(target, value, index);
 }
 
-static uint32_t riscv_get_dmi_address(const struct target *target, uint32_t dm_address)
+uint32_t riscv_get_dmi_address(const struct target *target, uint32_t dm_address)
 {
 	assert(target);
 	RISCV_INFO(r);

src/target/riscv/riscv.h

@@ -440,6 +440,8 @@ void riscv_fill_dm_write(struct target *target, char *buf, uint64_t a, uint32_t
 void riscv_fill_dm_read(struct target *target, char *buf, uint64_t a);
 int riscv_get_dmi_scan_length(struct target *target);
 
+uint32_t riscv_get_dmi_address(const struct target *target, uint32_t dm_address);
+
 int riscv_enumerate_triggers(struct target *target);
 
 int riscv_add_watchpoint(struct target *target, struct watchpoint *watchpoint);