riscv-openocd/src/target/xtensa/xtensa_debug_module.c

// SPDX-License-Identifier: GPL-2.0-or-later

/***************************************************************************
 *   Xtensa Debug Module (XDM) Support for OpenOCD                         *
 *   Copyright (C) 2020-2022 Cadence Design Systems, Inc.                  *
 *   Copyright (C) 2019 Espressif Systems Ltd.                             *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <helper/align.h>
#include "xtensa_debug_module.h"

#define TAPINS_PWRCTL           0x08
#define TAPINS_PWRSTAT          0x09
#define TAPINS_NARSEL           0x1C
#define TAPINS_IDCODE           0x1E
#define TAPINS_BYPASS           0x1F

#define TAPINS_PWRCTL_LEN       8
#define TAPINS_PWRSTAT_LEN      8
#define TAPINS_NARSEL_ADRLEN    8
#define TAPINS_NARSEL_DATALEN   32
#define TAPINS_IDCODE_LEN       32
#define TAPINS_BYPASS_LEN       1

/* Table of power register offsets for APB space */
static const struct xtensa_dm_pwr_reg_offsets xdm_pwr_regs[XDMREG_PWRNUM] =
	XTENSA_DM_PWR_REG_OFFSETS;

/* Table of debug register offsets for Nexus and APB space */
static const struct xtensa_dm_reg_offsets xdm_regs[XDMREG_NUM] =
	XTENSA_DM_REG_OFFSETS;

static enum xtensa_dm_reg xtensa_dm_regaddr_to_id(uint32_t addr)
{
	enum xtensa_dm_reg id;
	uint32_t addr_masked = (addr & (XTENSA_DM_APB_ALIGN - 1));
	for (id = XDMREG_TRAXID; id < XDMREG_NUM; id++)
		if (xdm_regs[id].apb == addr_masked)
			break;
	return id;
}

static void xtensa_dm_add_set_ir(struct xtensa_debug_module *dm, uint8_t value)
{
	struct scan_field field;
	uint8_t t[4] = { 0, 0, 0, 0 };

	memset(&field, 0, sizeof(field));
	field.num_bits = dm->tap->ir_length;
	field.out_value = t;
	buf_set_u32(t, 0, field.num_bits, value);
	jtag_add_ir_scan(dm->tap, &field, TAP_IDLE);
}

static void xtensa_dm_add_dr_scan(struct xtensa_debug_module *dm,
	int len,
	const uint8_t *src,
	uint8_t *dest,
	tap_state_t endstate)
{
	struct scan_field field;

	memset(&field, 0, sizeof(field));
	field.num_bits = len;
	field.out_value = src;
	field.in_value = dest;
	jtag_add_dr_scan(dm->tap, 1, &field, endstate);
}

int xtensa_dm_init(struct xtensa_debug_module *dm, const struct xtensa_debug_module_config *cfg)
{
	if (!dm || !cfg)
		return ERROR_FAIL;
	if (!IS_ALIGNED(cfg->ap_offset, XTENSA_DM_APB_ALIGN)) {
		LOG_ERROR("Xtensa DM APB offset must be aligned to a %dKB multiple",
			XTENSA_DM_APB_ALIGN / 1024);
		return ERROR_FAIL;
	}

	dm->pwr_ops = cfg->pwr_ops;
	dm->dbg_ops = cfg->dbg_ops;
	dm->tap = cfg->tap;
	dm->queue_tdi_idle = cfg->queue_tdi_idle;
	dm->queue_tdi_idle_arg = cfg->queue_tdi_idle_arg;
	dm->dap = cfg->dap;
	dm->debug_ap = cfg->debug_ap;
	dm->debug_apsel = cfg->debug_apsel;
	dm->ap_offset = cfg->ap_offset;
	return ERROR_OK;
}

void xtensa_dm_deinit(struct xtensa_debug_module *dm)
{
	if (dm->debug_ap) {
		dap_put_ap(dm->debug_ap);
		dm->debug_ap = NULL;
	}
}

int xtensa_dm_poll(struct xtensa_debug_module *dm)
{
	/* Check if debug_ap is available to prevent segmentation fault.
	 * If the re-examination after an error does not find a MEM-AP
	 * (e.g. the target stopped communicating), debug_ap pointer
	 * can suddenly become NULL.
	 */
	return (!dm || (dm->dap && !dm->debug_ap)) ? ERROR_FAIL : ERROR_OK;
}

int xtensa_dm_examine(struct xtensa_debug_module *dm)
{
	struct adiv5_dap *swjdp = dm->dap;
	int retval = ERROR_OK;

	if (swjdp) {
		LOG_DEBUG("DM examine: DAP AP select %d", dm->debug_apsel);
		if (dm->debug_ap) {
			dap_put_ap(dm->debug_ap);
			dm->debug_ap = NULL;
		}
		if (dm->debug_apsel == DP_APSEL_INVALID) {
			LOG_DEBUG("DM examine: search for APB-type MEM-AP...");
			/* TODO: Determine whether AP_TYPE_AXI_AP APs can be supported... */
			retval = dap_find_get_ap(swjdp, AP_TYPE_APB_AP, &dm->debug_ap);
			if (retval != ERROR_OK) {
				LOG_ERROR("Could not find MEM-AP to control the core");
				return retval;
			}
		} else {
			dm->debug_ap = dap_get_ap(swjdp, dm->debug_apsel);
		}

		/* TODO: Allow a user-specified AP instead of relying on AP_TYPE_APB_AP */
		dm->debug_apsel = dm->debug_ap->ap_num;
		LOG_DEBUG("DM examine: Setting apsel to %d", dm->debug_apsel);

		/* Leave (only) generic DAP stuff for debugport_init(); */
		dm->debug_ap->memaccess_tck = 8;

		retval = mem_ap_init(dm->debug_ap);
		if (retval != ERROR_OK) {
			LOG_ERROR("MEM-AP init failed: %d", retval);
			return retval;
		}

		/* TODO: how to set autoincrement range? Hard-code it to 1024 bytes for now */
		dm->debug_ap->tar_autoincr_block = (1 << 10);
	}

	return retval;
}

int xtensa_dm_queue_enable(struct xtensa_debug_module *dm)
{
	return dm->dbg_ops->queue_reg_write(dm, XDMREG_DCRSET, OCDDCR_ENABLEOCD);
}

int xtensa_dm_queue_reg_read(struct xtensa_debug_module *dm, enum xtensa_dm_reg reg, uint8_t *value)
{
	if (reg >= XDMREG_NUM) {
		LOG_ERROR("Invalid DBG reg ID %d!", reg);
		return ERROR_FAIL;
	}
	if (dm->dap)
		/* NOTE: Future optimization: mem_ap_read_u32() offers higher performance with
		 * queued reads, but requires an API change to pass value as a 32-bit pointer.
		 */
		return mem_ap_read_buf(dm->debug_ap, value, 4, 1, xdm_regs[reg].apb + dm->ap_offset);
	uint8_t regdata = (xdm_regs[reg].nar << 1) | 0;
	uint8_t dummy[4] = { 0, 0, 0, 0 };
	xtensa_dm_add_set_ir(dm, TAPINS_NARSEL);
	xtensa_dm_add_dr_scan(dm, TAPINS_NARSEL_ADRLEN, &regdata, NULL, TAP_IDLE);
	xtensa_dm_add_dr_scan(dm, TAPINS_NARSEL_DATALEN, dummy, value, TAP_IDLE);
	return ERROR_OK;
}

int xtensa_dm_queue_reg_write(struct xtensa_debug_module *dm, enum xtensa_dm_reg reg, uint32_t value)
{
	if (reg >= XDMREG_NUM) {
		LOG_ERROR("Invalid DBG reg ID %d!", reg);
		return ERROR_FAIL;
	}
	if (dm->dap)
		return mem_ap_write_u32(dm->debug_ap, xdm_regs[reg].apb + dm->ap_offset, value);
	uint8_t regdata = (xdm_regs[reg].nar << 1) | 1;
	uint8_t valdata[] = { value, value >> 8, value >> 16, value >> 24 };
	xtensa_dm_add_set_ir(dm, TAPINS_NARSEL);
	xtensa_dm_add_dr_scan(dm, TAPINS_NARSEL_ADRLEN, &regdata, NULL, TAP_IDLE);
	xtensa_dm_add_dr_scan(dm, TAPINS_NARSEL_DATALEN, valdata, NULL, TAP_IDLE);
	return ERROR_OK;
}

int xtensa_dm_queue_pwr_reg_read(struct xtensa_debug_module *dm,
	enum xtensa_dm_pwr_reg reg,
	uint8_t *data,
	uint32_t clear)
{
	if (reg >= XDMREG_PWRNUM) {
		LOG_ERROR("Invalid PWR reg ID %d!", reg);
		return ERROR_FAIL;
	}
	if (dm->dap) {
		/* NOTE: Future optimization: mem_ap_read_u32() offers higher performance with
		 * queued reads, but requires an API change to pass value as a 32-bit pointer.
		 */
		uint32_t apbreg = xdm_pwr_regs[reg].apb + dm->ap_offset;
		int retval = mem_ap_read_buf(dm->debug_ap, data, 4, 1, apbreg);
		if (retval == ERROR_OK)
			retval = mem_ap_write_u32(dm->debug_ap, apbreg, clear);
		return retval;
	}
	uint8_t value_clr = (uint8_t)clear;
	uint8_t tap_insn = (reg == XDMREG_PWRCTL) ? TAPINS_PWRCTL : TAPINS_PWRSTAT;
	int tap_insn_sz = (reg == XDMREG_PWRCTL) ? TAPINS_PWRCTL_LEN : TAPINS_PWRSTAT_LEN;
	xtensa_dm_add_set_ir(dm, tap_insn);
	xtensa_dm_add_dr_scan(dm, tap_insn_sz, &value_clr, data, TAP_IDLE);
	return ERROR_OK;
}

int xtensa_dm_queue_pwr_reg_write(struct xtensa_debug_module *dm,
	enum xtensa_dm_pwr_reg reg,
	uint32_t data)
{
	if (reg >= XDMREG_PWRNUM) {
		LOG_ERROR("Invalid PWR reg ID %d!", reg);
		return ERROR_FAIL;
	}
	if (dm->dap) {
		uint32_t apbreg = xdm_pwr_regs[reg].apb + dm->ap_offset;
		return mem_ap_write_u32(dm->debug_ap, apbreg, data);
	}
	uint8_t tap_insn = (reg == XDMREG_PWRCTL) ? TAPINS_PWRCTL : TAPINS_PWRSTAT;
	int tap_insn_sz = (reg == XDMREG_PWRCTL) ? TAPINS_PWRCTL_LEN : TAPINS_PWRSTAT_LEN;
	uint8_t value = (uint8_t)data;
	xtensa_dm_add_set_ir(dm, tap_insn);
	xtensa_dm_add_dr_scan(dm, tap_insn_sz, &value, NULL, TAP_IDLE);
	return ERROR_OK;
}

int xtensa_dm_device_id_read(struct xtensa_debug_module *dm)
{
	uint8_t id_buf[sizeof(uint32_t)];

	dm->dbg_ops->queue_reg_read(dm, XDMREG_OCDID, id_buf);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res != ERROR_OK)
		return res;
	dm->device_id = buf_get_u32(id_buf, 0, 32);
	return ERROR_OK;
}

int xtensa_dm_power_status_read(struct xtensa_debug_module *dm, uint32_t clear)
{
	uint8_t stat_buf[sizeof(uint32_t)] = { 0, 0, 0, 0 };
	uint8_t stath_buf[sizeof(uint32_t)] = { 0, 0, 0, 0 };

	/* TODO: JTAG does not work when PWRCTL_JTAGDEBUGUSE is not set.
	 * It is set in xtensa_examine(), need to move reading of XDMREG_OCDID out of this function */
	/* dm->dbg_ops->queue_reg_read(dm, XDMREG_OCDID, id_buf);
	 *Read reset state */
	dm->pwr_ops->queue_reg_read(dm, XDMREG_PWRSTAT, stat_buf, clear);
	dm->pwr_ops->queue_reg_read(dm, XDMREG_PWRSTAT, stath_buf, clear);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res != ERROR_OK)
		return res;
	dm->power_status.stat = buf_get_u32(stat_buf, 0, 32);
	dm->power_status.stath = buf_get_u32(stath_buf, 0, 32);
	return res;
}

int xtensa_dm_core_status_read(struct xtensa_debug_module *dm)
{
	uint8_t dsr_buf[sizeof(uint32_t)];

	xtensa_dm_queue_enable(dm);
	dm->dbg_ops->queue_reg_read(dm, XDMREG_DSR, dsr_buf);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res != ERROR_OK)
		return res;
	dm->core_status.dsr = buf_get_u32(dsr_buf, 0, 32);
	return res;
}

int xtensa_dm_core_status_clear(struct xtensa_debug_module *dm, xtensa_dsr_t bits)
{
	dm->dbg_ops->queue_reg_write(dm, XDMREG_DSR, bits);
	xtensa_dm_queue_tdi_idle(dm);
	return xtensa_dm_queue_execute(dm);
}

int xtensa_dm_read(struct xtensa_debug_module *dm, uint32_t addr, uint32_t *val)
{
	enum xtensa_dm_reg reg = xtensa_dm_regaddr_to_id(addr);
	uint8_t buf[sizeof(uint32_t)];
	if (reg < XDMREG_NUM) {
		xtensa_dm_queue_enable(dm);
		dm->dbg_ops->queue_reg_read(dm, reg, buf);
		xtensa_dm_queue_tdi_idle(dm);
		int res = xtensa_dm_queue_execute(dm);
		if (res == ERROR_OK && val)
			*val = buf_get_u32(buf, 0, 32);
		return res;
	}
	return ERROR_FAIL;
}

int xtensa_dm_write(struct xtensa_debug_module *dm, uint32_t addr, uint32_t val)
{
	enum xtensa_dm_reg reg = xtensa_dm_regaddr_to_id(addr);
	if (reg < XDMREG_NUM) {
		xtensa_dm_queue_enable(dm);
		dm->dbg_ops->queue_reg_write(dm, reg, val);
		xtensa_dm_queue_tdi_idle(dm);
		return xtensa_dm_queue_execute(dm);
	}
	return ERROR_FAIL;
}

int xtensa_dm_trace_start(struct xtensa_debug_module *dm, struct xtensa_trace_start_config *cfg)
{
	/*Turn off trace unit so we can start a new trace. */
	dm->dbg_ops->queue_reg_write(dm, XDMREG_TRAXCTRL, 0);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res != ERROR_OK)
		return res;

	/*Set up parameters */
	dm->dbg_ops->queue_reg_write(dm, XDMREG_TRAXADDR, 0);
	if (cfg->stopmask != XTENSA_STOPMASK_DISABLED) {
		dm->dbg_ops->queue_reg_write(dm, XDMREG_PCMATCHCTRL,
			(cfg->stopmask << PCMATCHCTRL_PCML_SHIFT));
		dm->dbg_ops->queue_reg_write(dm, XDMREG_TRIGGERPC, cfg->stoppc);
	}
	dm->dbg_ops->queue_reg_write(dm, XDMREG_DELAYCNT, cfg->after);
	/*Options are mostly hardcoded for now. ToDo: make this more configurable. */
	dm->dbg_ops->queue_reg_write(
		dm,
		XDMREG_TRAXCTRL,
		TRAXCTRL_TREN |
		((cfg->stopmask != XTENSA_STOPMASK_DISABLED) ? TRAXCTRL_PCMEN : 0) | TRAXCTRL_TMEN |
		(cfg->after_is_words ? 0 : TRAXCTRL_CNTU) | (0 << TRAXCTRL_SMPER_SHIFT) | TRAXCTRL_PTOWS);
	xtensa_dm_queue_tdi_idle(dm);
	return xtensa_dm_queue_execute(dm);
}

int xtensa_dm_trace_stop(struct xtensa_debug_module *dm, bool pto_enable)
{
	uint8_t traxctl_buf[sizeof(uint32_t)];
	uint32_t traxctl;
	struct xtensa_trace_status trace_status;

	dm->dbg_ops->queue_reg_read(dm, XDMREG_TRAXCTRL, traxctl_buf);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res != ERROR_OK)
		return res;
	traxctl = buf_get_u32(traxctl_buf, 0, 32);

	if (!pto_enable)
		traxctl &= ~(TRAXCTRL_PTOWS | TRAXCTRL_PTOWT);

	dm->dbg_ops->queue_reg_write(dm, XDMREG_TRAXCTRL, traxctl | TRAXCTRL_TRSTP);
	xtensa_dm_queue_tdi_idle(dm);
	res = xtensa_dm_queue_execute(dm);
	if (res != ERROR_OK)
		return res;

	/*Check current status of trace hardware */
	res = xtensa_dm_trace_status_read(dm, &trace_status);
	if (res != ERROR_OK)
		return res;

	if (trace_status.stat & TRAXSTAT_TRACT) {
		LOG_ERROR("Failed to stop tracing (0x%x)!", trace_status.stat);
		return ERROR_FAIL;
	}
	return ERROR_OK;
}

int xtensa_dm_trace_status_read(struct xtensa_debug_module *dm, struct xtensa_trace_status *status)
{
	uint8_t traxstat_buf[sizeof(uint32_t)];

	dm->dbg_ops->queue_reg_read(dm, XDMREG_TRAXSTAT, traxstat_buf);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res == ERROR_OK && status)
		status->stat = buf_get_u32(traxstat_buf, 0, 32);
	return res;
}

int xtensa_dm_trace_config_read(struct xtensa_debug_module *dm, struct xtensa_trace_config *config)
{
	uint8_t traxctl_buf[sizeof(uint32_t)];
	uint8_t memadrstart_buf[sizeof(uint32_t)];
	uint8_t memadrend_buf[sizeof(uint32_t)];
	uint8_t adr_buf[sizeof(uint32_t)];

	if (!config)
		return ERROR_FAIL;

	dm->dbg_ops->queue_reg_read(dm, XDMREG_TRAXCTRL, traxctl_buf);
	dm->dbg_ops->queue_reg_read(dm, XDMREG_MEMADDRSTART, memadrstart_buf);
	dm->dbg_ops->queue_reg_read(dm, XDMREG_MEMADDREND, memadrend_buf);
	dm->dbg_ops->queue_reg_read(dm, XDMREG_TRAXADDR, adr_buf);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res == ERROR_OK) {
		config->ctrl = buf_get_u32(traxctl_buf, 0, 32);
		config->memaddr_start = buf_get_u32(memadrstart_buf, 0, 32);
		config->memaddr_end = buf_get_u32(memadrend_buf, 0, 32);
		config->addr = buf_get_u32(adr_buf, 0, 32);
	}
	return res;
}

int xtensa_dm_trace_data_read(struct xtensa_debug_module *dm, uint8_t *dest, uint32_t size)
{
	if (!dest)
		return ERROR_FAIL;

	for (unsigned int i = 0; i < size / 4; i++)
		dm->dbg_ops->queue_reg_read(dm, XDMREG_TRAXDATA, &dest[i * 4]);
	xtensa_dm_queue_tdi_idle(dm);
	return xtensa_dm_queue_execute(dm);
}

int xtensa_dm_perfmon_enable(struct xtensa_debug_module *dm, int counter_id,
	const struct xtensa_perfmon_config *config)
{
	if (!config)
		return ERROR_FAIL;

	uint8_t pmstat_buf[4];
	uint32_t pmctrl = ((config->tracelevel) << 4) +
		(config->select << 8) +
		(config->mask << 16) +
		(config->kernelcnt << 3);

	/* enable performance monitor */
	dm->dbg_ops->queue_reg_write(dm, XDMREG_PMG, 0x1);
	/* reset counter */
	dm->dbg_ops->queue_reg_write(dm, XDMREG_PM0 + counter_id, 0);
	dm->dbg_ops->queue_reg_write(dm, XDMREG_PMCTRL0 + counter_id, pmctrl);
	dm->dbg_ops->queue_reg_read(dm, XDMREG_PMSTAT0 + counter_id, pmstat_buf);
	xtensa_dm_queue_tdi_idle(dm);
	return xtensa_dm_queue_execute(dm);
}

int xtensa_dm_perfmon_dump(struct xtensa_debug_module *dm, int counter_id,
	struct xtensa_perfmon_result *out_result)
{
	uint8_t pmstat_buf[4];
	uint8_t pmcount_buf[4];

	dm->dbg_ops->queue_reg_read(dm, XDMREG_PMSTAT0 + counter_id, pmstat_buf);
	dm->dbg_ops->queue_reg_read(dm, XDMREG_PM0 + counter_id, pmcount_buf);
	xtensa_dm_queue_tdi_idle(dm);
	int res = xtensa_dm_queue_execute(dm);
	if (res == ERROR_OK) {
		uint32_t stat = buf_get_u32(pmstat_buf, 0, 32);
		uint64_t result = buf_get_u32(pmcount_buf, 0, 32);

		/* TODO: if counter # counter_id+1 has 'select' set to 1, use its value as the
		* high 32 bits of the counter. */
		if (out_result) {
			out_result->overflow = ((stat & 1) != 0);
			out_result->value = result;
		}
	}

	return res;
}