path: root/src/jtag/commands.c

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

/***************************************************************************
 *   Copyright (C) 2005 by Dominic Rath                                    *
 *   Dominic.Rath@gmx.de                                                   *
 *                                                                         *
 *   Copyright (C) 2007,2008 Øyvind Harboe                                 *
 *   oyvind.harboe@zylin.com                                               *
 *                                                                         *
 *   Copyright (C) 2009 SoftPLC Corporation                                *
 *       http://softplc.com                                                *
 *   dick@softplc.com                                                      *
 *                                                                         *
 *   Copyright (C) 2009 Zachary T Welch                                    *
 *   zw@superlucidity.net                                                  *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <jtag/jtag.h>
#include <transport/transport.h>
#include "commands.h"

struct cmd_queue_page {
	struct cmd_queue_page *next;
	void *address;
	size_t used;
};

#define CMD_QUEUE_PAGE_SIZE (1024 * 1024)
static struct cmd_queue_page *cmd_queue_pages;
static struct cmd_queue_page *cmd_queue_pages_tail;

struct jtag_command *jtag_command_queue;
static struct jtag_command **next_command_pointer = &jtag_command_queue;

void jtag_queue_command(struct jtag_command *cmd)
{
	if (!transport_is_jtag()) {
		/*
		 * FIXME: This should not happen!
		 * There could be old code that queues jtag commands with non jtag interfaces so, for
		 * the moment simply highlight it by log an error.
		 * We should fix it quitting with assert(0) because it is an internal error, or returning
		 * an error after call to jtag_command_queue_reset() to free the jtag queue and avoid
		 * memory leaks.
		 * The fix can be applied immediately after next release (v0.11.0 ?)
		 */
		LOG_ERROR("JTAG API jtag_queue_command() called on non JTAG interface");
	}

	/* this command goes on the end, so ensure the queue terminates */
	cmd->next = NULL;

	struct jtag_command **last_cmd = next_command_pointer;
	assert(last_cmd);
	assert(!*last_cmd);
	*last_cmd = cmd;

	/* store location where the next command pointer will be stored */
	next_command_pointer = &cmd->next;
}

void *cmd_queue_alloc(size_t size)
{
	struct cmd_queue_page **p_page = &cmd_queue_pages;
	int offset;
	uint8_t *t;

	/*
	 * WARNING:
	 *    We align/round the *SIZE* per below
	 *    so that all pointers returned by
	 *    this function are reasonably well
	 *    aligned.
	 *
	 * If we did not, then an "odd-length" request would cause the
	 * *next* allocation to be at an *odd* address, and because
	 * this function has the same type of api as malloc() - we
	 * must also return pointers that have the same type of
	 * alignment.
	 *
	 * What I do not/have is a reasonable portable means
	 * to align by...
	 *
	 * The solution here, is based on these suggestions.
	 * http://gcc.gnu.org/ml/gcc-help/2008-12/msg00041.html
	 *
	 */
	union worse_case_align {
		int i;
		long l;
		float f;
		void *v;
	};
#define ALIGN_SIZE  (sizeof(union worse_case_align))

	/* The alignment process. */
	size = (size + ALIGN_SIZE - 1) & (~(ALIGN_SIZE - 1));
	/* Done... */

	if (*p_page) {
		p_page = &cmd_queue_pages_tail;
		if (CMD_QUEUE_PAGE_SIZE - (*p_page)->used < size)
			p_page = &((*p_page)->next);
	}

	if (!*p_page) {
		*p_page = malloc(sizeof(struct cmd_queue_page));
		(*p_page)->used = 0;
		size_t alloc_size = (size < CMD_QUEUE_PAGE_SIZE) ?
					CMD_QUEUE_PAGE_SIZE : size;
		(*p_page)->address = malloc(alloc_size);
		(*p_page)->next = NULL;
		cmd_queue_pages_tail = *p_page;
	}

	offset = (*p_page)->used;
	(*p_page)->used += size;

	t = (*p_page)->address;
	return t + offset;
}

static void cmd_queue_free(void)
{
	struct cmd_queue_page *page = cmd_queue_pages;

	while (page) {
		struct cmd_queue_page *last = page;
		free(page->address);
		page = page->next;
		free(last);
	}

	cmd_queue_pages = NULL;
	cmd_queue_pages_tail = NULL;
}

void jtag_command_queue_reset(void)
{
	cmd_queue_free();

	jtag_command_queue = NULL;
	next_command_pointer = &jtag_command_queue;
}

/**
 * Copy a struct scan_field for insertion into the queue.
 *
 * This allocates a new copy of out_value using cmd_queue_alloc.
 */
void jtag_scan_field_clone(struct scan_field *dst, const struct scan_field *src)
{
	dst->num_bits	= src->num_bits;
	dst->out_value	= buf_cpy(src->out_value, cmd_queue_alloc(DIV_ROUND_UP(src->num_bits, 8)), src->num_bits);
	dst->in_value	= src->in_value;
}

enum scan_type jtag_scan_type(const struct scan_command *cmd)
{
	int i;
	int type = 0;

	for (i = 0; i < cmd->num_fields; i++) {
		if (cmd->fields[i].in_value)
			type |= SCAN_IN;
		if (cmd->fields[i].out_value)
			type |= SCAN_OUT;
	}

	return type;
}

int jtag_scan_size(const struct scan_command *cmd)
{
	int bit_count = 0;
	int i;

	/* count bits in scan command */
	for (i = 0; i < cmd->num_fields; i++)
		bit_count += cmd->fields[i].num_bits;

	return bit_count;
}

int jtag_build_buffer(const struct scan_command *cmd, uint8_t **buffer)
{
	int bit_count = 0;
	int i;

	bit_count = jtag_scan_size(cmd);
	*buffer = calloc(1, DIV_ROUND_UP(bit_count, 8));

	bit_count = 0;

	LOG_DEBUG_IO("%s num_fields: %i",
			cmd->ir_scan ? "IRSCAN" : "DRSCAN",
			cmd->num_fields);

	for (i = 0; i < cmd->num_fields; i++) {
		if (cmd->fields[i].out_value) {
			if (LOG_LEVEL_IS(LOG_LVL_DEBUG_IO)) {
				char *char_buf = buf_to_hex_str(cmd->fields[i].out_value,
						(cmd->fields[i].num_bits > DEBUG_JTAG_IOZ)
						? DEBUG_JTAG_IOZ
								: cmd->fields[i].num_bits);

				LOG_DEBUG("fields[%i].out_value[%i]: 0x%s", i,
						cmd->fields[i].num_bits, char_buf);
				free(char_buf);
			}
			buf_set_buf(cmd->fields[i].out_value, 0, *buffer,
					bit_count, cmd->fields[i].num_bits);
		} else {
			LOG_DEBUG_IO("fields[%i].out_value[%i]: NULL",
					i, cmd->fields[i].num_bits);
		}

		bit_count += cmd->fields[i].num_bits;
	}

	/*LOG_DEBUG_IO("bit_count totalling: %i",  bit_count); */

	return bit_count;
}

int jtag_read_buffer(uint8_t *buffer, const struct scan_command *cmd)
{
	int i;
	int bit_count = 0;
	int retval;

	/* we return ERROR_OK, unless a check fails, or a handler reports a problem */
	retval = ERROR_OK;

	for (i = 0; i < cmd->num_fields; i++) {
		/* if neither in_value nor in_handler
		 * are specified we don't have to examine this field
		 */
		if (cmd->fields[i].in_value) {
			int num_bits = cmd->fields[i].num_bits;
			uint8_t *captured = buf_set_buf(buffer, bit_count,
					malloc(DIV_ROUND_UP(num_bits, 8)), 0, num_bits);

			if (LOG_LEVEL_IS(LOG_LVL_DEBUG_IO)) {
				char *char_buf = buf_to_hex_str(captured,
						(num_bits > DEBUG_JTAG_IOZ)
						? DEBUG_JTAG_IOZ
								: num_bits);

				LOG_DEBUG("fields[%i].in_value[%i]: 0x%s",
						i, num_bits, char_buf);
				free(char_buf);
			}

			if (cmd->fields[i].in_value)
				buf_cpy(captured, cmd->fields[i].in_value, num_bits);

			free(captured);
		}
		bit_count += cmd->fields[i].num_bits;
	}

	return retval;
}