/*
 * This file is part of the Black Magic Debug project.
 *
 * Copyright (C) 2011  Black Sphere Technologies Ltd.
 * Written by Gareth McMullin <gareth@blacksphere.co.nz>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "general.h"
#include "target.h"
#include "gdb_if.h"

#if !defined(STM32F0) && !defined(STM32F1) && !defined(STM32F2) && !defined(STM32F3) && !defined(STM32F4) && \
	!defined(STM32F7) && !defined(STM32L0) && !defined(STM32L1) && !defined(STM32G0) && !defined(STM32G4)

/* clang-format off */
static const uint32_t crc32_table[] = {
	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
	0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
	0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
	0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
	0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
	0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
	0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
	0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
	0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
	0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
	0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
	0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
	0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
	0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
	0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
	0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
	0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
	0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
	0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
	0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
	0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
	0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
	0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
	0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
	0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
	0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
	0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
	0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
	0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
	0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
	0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
	0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
	0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
	0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
	0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
	0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
	0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
	0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
	0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
	0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
	0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
	0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
	0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4,
};

/* clang-format on */

static uint32_t crc32_calc(const uint32_t crc, const uint8_t data)
{
	return (crc << 8U) ^ crc32_table[((crc >> 24U) ^ data) & 0xffU];
}

static bool generic_crc32(target_s *const target, uint32_t *const result, const uint32_t base, const size_t len)
{
	uint32_t crc = 0xffffffffU;
#if CONFIG_BMDA == 1
	/*
	 * Reading a 2 MByte on a H743 takes about 80 s@128, 28s @ 1k,
	 * 22 s @ 4k and 21 s @ 64k
	 */
	uint8_t bytes[4096U];
#else
	uint8_t bytes[128U];
#endif

	uint32_t last_time = platform_time_ms();
	for (size_t offset = 0; offset < len; offset += sizeof(bytes)) {
		const uint32_t actual_time = platform_time_ms();
		if (actual_time > last_time + 1000U) {
			last_time = actual_time;
			gdb_if_putchar(0, true);
		}
		const size_t read_len = MIN(sizeof(bytes), len - offset);
		if (target_mem32_read(target, bytes, base + offset, (read_len + 3U) & ~3U)) {
			DEBUG_ERROR("%s: error around address 0x%08" PRIx32 "\n", __func__, (uint32_t)(base + offset));
			return false;
		}

		for (size_t i = 0; i < read_len; i++)
			crc = crc32_calc(crc, bytes[i]);
	}
	*result = crc;
	return true;
}

#else
#include <libopencm3/stm32/crc.h>
#include "buffer_utils.h"

static bool stm32_crc32(target_s *const target, uint32_t *const result, const uint32_t base, const size_t len)
{
	uint8_t bytes[1024U]; /* ADIv5 MEM-AP AutoInc range */

	CRC_CR |= CRC_CR_RESET;

	uint32_t last_time = platform_time_ms();
	const size_t adjusted_len = len & ~3U;
	for (size_t offset = 0; offset < adjusted_len; offset += sizeof(bytes)) {
		const uint32_t actual_time = platform_time_ms();
		if (actual_time > last_time + 1000U) {
			last_time = actual_time;
			gdb_if_putchar(0, true);
		}
		const size_t read_len = MIN(sizeof(bytes), adjusted_len - offset);
		if (target_mem32_read(target, bytes, base + offset, read_len)) {
			DEBUG_ERROR("%s: error around address 0x%08" PRIx32 "\n", __func__, (uint32_t)(base + offset));
			return false;
		}

		for (size_t i = 0; i < read_len; i += 4U)
			CRC_DR = read_be4(bytes, i);
	}

	uint32_t crc = CRC_DR;

	const size_t remainder = len - adjusted_len;
	if (remainder) {
		if (target_mem32_read(target, bytes, base + adjusted_len, remainder)) {
			DEBUG_ERROR("%s: error around address 0x%08" PRIx32 "\n", __func__, (uint32_t)(base + adjusted_len));
			return false;
		}
		for (size_t offset = 0; offset < remainder; ++offset) {
			crc ^= bytes[offset] << 24U;
			for (size_t i = 0; i < 8U; i++) {
				if (crc & 0x80000000U)
					crc = (crc << 1U) ^ 0x4c11db7U;
				else
					crc <<= 1U;
			}
		}
	}
	*result = crc;
	return true;
}
#endif

/* Shim to dispatch host-specific implementation (and keep the `__func__` meaningful) */
bool bmd_crc32(target_s *const target, uint32_t *const result, const uint32_t base, const size_t len)
{
#ifndef DEBUG_INFO_IS_NOOP
	const uint32_t start_time = platform_time_ms();
#endif
#if !defined(STM32F0) && !defined(STM32F1) && !defined(STM32F2) && !defined(STM32F3) && !defined(STM32F4) && \
	!defined(STM32F7) && !defined(STM32L0) && !defined(STM32L1) && !defined(STM32G0) && !defined(STM32G4)
	const bool status = generic_crc32(target, result, base, len);
#else
	const bool status = stm32_crc32(target, result, base, len);
#endif
#ifndef DEBUG_INFO_IS_NOOP
	/* "generic_crc32: 08000110+75272 -> 1353ms, 54 KiB/s" */
	/* "stm32_crc32: 08000110+75272 -> 237ms, 310 KiB/s" */
	const uint32_t end_time = platform_time_ms();
	const uint32_t time_elapsed = end_time - start_time;
	DEBUG_INFO("%s: 0x%08" PRIx32 "+%" PRIu32 " -> %" PRIu32 "ms", __func__, base, (uint32_t)len, time_elapsed);
	if (len >= 512U) {
		const uint32_t speed = len * 1000U / time_elapsed / 1024U;
		DEBUG_INFO(", %" PRIu32 " KiB/s", speed);
	}
	DEBUG_INFO("\n");
#endif
	return status;
}
