dmem.c

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// SPDX-License-Identifier: GPL-2.0-or-later
 
/* Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com/ */
 
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
 
#include <sys/mman.h>
 
#include <helper/align.h>
#include <helper/types.h>
#include <helper/system.h>
#include <helper/time_support.h>
#include <helper/list.h>
#include <jtag/interface.h>
 
#include <target/arm_adi_v5.h>
#include <transport/transport.h>
 
struct dmem_emu_ap_info {
    uint64_t ap_num;
    /* Emulation mode AP state variables */
    uint32_t apbap_tar;
    uint32_t apbap_csw;
};
 
/*
 * This bit tells if the transaction is coming in from jtag or not
 * we just mask this out to emulate direct address access
 */
#define ARM_APB_PADDR31  BIT(31)
 
static void *dmem_map_base, *dmem_virt_base_addr;
static size_t dmem_mapped_size;
 
/* Default dmem device. */
#define DMEM_DEV_PATH_DEFAULT   "/dev/mem"
static char *dmem_dev_path;
static uint64_t dmem_dap_base_address;
static unsigned int dmem_dap_max_aps = 1;
static uint32_t dmem_dap_ap_offset = 0x100;
 
/* DAP error code. */
static int dmem_dap_retval = ERROR_OK;
 
/* AP Emulation Mode */
static uint64_t dmem_emu_base_address;
static uint64_t dmem_emu_size;
static void *dmem_emu_map_base, *dmem_emu_virt_base_addr;
static size_t dmem_emu_mapped_size;
#define DMEM_MAX_EMULATE_APS 5
static unsigned int dmem_emu_ap_count;
static struct dmem_emu_ap_info dmem_emu_ap_list[DMEM_MAX_EMULATE_APS];
 
/*
 * This helper is used to determine the TAR increment size in bytes.  The AP's
 * CSW encoding for SIZE supports byte count decode using "1 << SIZE".
 */
static uint32_t dmem_memap_tar_inc(uint32_t csw)
{
    if ((csw & CSW_ADDRINC_MASK) != 0)
        return 1 << (csw & CSW_SIZE_MASK);
    return 0;
}
 
/*
 * EMULATION MODE: In Emulation MODE, we assume the following:
 * TCL still describes as system is operational from the view of AP (ex. jtag)
 * However, the hardware doesn't permit direct memory access to these APs
 * (only permitted via JTAG).
 *
 * So, the access to these APs have to be decoded to a memory map
 * access which we can directly access.
 *
 * A few TI processors have this issue.
 */
static bool dmem_is_emulated_ap(struct adiv5_ap *ap, unsigned int *idx)
{
    for (unsigned int i = 0; i < dmem_emu_ap_count; i++) {
        if (ap->ap_num == dmem_emu_ap_list[i].ap_num) {
            *idx = i;
            return true;
        }
    }
    return false;
}
 
static void dmem_emu_set_ap_reg(uint32_t addr, uint32_t val)
{
    addr &= ~ARM_APB_PADDR31;
 
    *(volatile uint32_t *)((uintptr_t)dmem_emu_virt_base_addr + addr) = val;
}
 
static uint32_t dmem_emu_get_ap_reg(uint32_t addr)
{
    addr &= ~ARM_APB_PADDR31;
 
    return *(volatile uint32_t *)((uintptr_t)dmem_emu_virt_base_addr + addr);
}
 
static int dmem_emu_ap_q_read(unsigned int ap_idx, unsigned int reg, uint32_t *data)
{
    uint32_t addr;
    int ret = ERROR_OK;
    struct dmem_emu_ap_info *ap_info = &dmem_emu_ap_list[ap_idx];
 
    switch (reg) {
    case ADIV5_MEM_AP_REG_CSW:
        *data = ap_info->apbap_csw;
        break;
    case ADIV5_MEM_AP_REG_TAR:
        *data = ap_info->apbap_tar;
        break;
    case ADIV5_MEM_AP_REG_CFG:
        *data = 0;
        break;
    case ADIV5_MEM_AP_REG_BASE:
        *data = 0;
        break;
    case ADIV5_AP_REG_IDR:
        *data = 0;
        break;
    case ADIV5_MEM_AP_REG_BD0:
    case ADIV5_MEM_AP_REG_BD1:
    case ADIV5_MEM_AP_REG_BD2:
    case ADIV5_MEM_AP_REG_BD3:
        addr = (ap_info->apbap_tar & ~0xf) + (reg & 0x0C);
 
        *data = dmem_emu_get_ap_reg(addr);
 
        break;
    case ADIV5_MEM_AP_REG_DRW:
        addr = ap_info->apbap_tar;
 
        *data = dmem_emu_get_ap_reg(addr);
 
        ap_info->apbap_tar += dmem_memap_tar_inc(ap_info->apbap_csw);
        break;
    default:
        LOG_INFO("%s: Unknown reg: 0x%02x", __func__, reg);
        ret = ERROR_FAIL;
        break;
    }
 
    /* Track the last error code. */
    if (ret != ERROR_OK)
        dmem_dap_retval = ret;
 
    return ret;
}
 
static int dmem_emu_ap_q_write(unsigned int ap_idx, unsigned int reg, uint32_t data)
{
    uint32_t addr;
    int ret = ERROR_OK;
    struct dmem_emu_ap_info *ap_info = &dmem_emu_ap_list[ap_idx];
 
    switch (reg) {
    case ADIV5_MEM_AP_REG_CSW:
        /*
         * This implementation only supports 32-bit accesses.
         * Force this by ensuring CSW_SIZE field indicates 32-BIT.
         */
        ap_info->apbap_csw = ((data & ~CSW_SIZE_MASK) | CSW_32BIT);
        break;
    case ADIV5_MEM_AP_REG_TAR:
        /*
         * This implementation only supports 32-bit accesses.
         * Force LS 2-bits of TAR to 00b
         */
        ap_info->apbap_tar = (data & ~0x3);
        break;
 
    case ADIV5_MEM_AP_REG_CFG:
    case ADIV5_MEM_AP_REG_BASE:
    case ADIV5_AP_REG_IDR:
        /* We don't use this, so we don't need to store */
        break;
 
    case ADIV5_MEM_AP_REG_BD0:
    case ADIV5_MEM_AP_REG_BD1:
    case ADIV5_MEM_AP_REG_BD2:
    case ADIV5_MEM_AP_REG_BD3:
        addr = (ap_info->apbap_tar & ~0xf) + (reg & 0x0C);
 
        dmem_emu_set_ap_reg(addr, data);
 
        break;
    case ADIV5_MEM_AP_REG_DRW:
        addr = ap_info->apbap_tar;
        dmem_emu_set_ap_reg(addr, data);
 
        ap_info->apbap_tar += dmem_memap_tar_inc(ap_info->apbap_csw);
        break;
    default:
        LOG_INFO("%s: Unknown reg: 0x%02x", __func__, reg);
        ret = EINVAL;
        break;
    }
 
    /* Track the last error code. */
    if (ret != ERROR_OK)
        dmem_dap_retval = ret;
 
    return ret;
}
 
/* AP MODE */
static uint32_t dmem_get_ap_reg_offset(struct adiv5_ap *ap, unsigned int reg)
{
    return (dmem_dap_ap_offset * ap->ap_num) + reg;
}
 
static void dmem_set_ap_reg(struct adiv5_ap *ap, unsigned int reg, uint32_t val)
{
    *(volatile uint32_t *)((uintptr_t)dmem_virt_base_addr +
                           dmem_get_ap_reg_offset(ap, reg)) = val;
}
 
static uint32_t dmem_get_ap_reg(struct adiv5_ap *ap, unsigned int reg)
{
    return *(volatile uint32_t *)((uintptr_t)dmem_virt_base_addr +
                                  dmem_get_ap_reg_offset(ap, reg));
}
 
static int dmem_dp_q_read(struct adiv5_dap *dap, unsigned int reg, uint32_t *data)
{
    if (!data)
        return ERROR_OK;
 
    switch (reg) {
    case DP_CTRL_STAT:
        *data = CDBGPWRUPACK | CSYSPWRUPACK;
        break;
 
    default:
        *data = 0;
        break;
    }
 
    return ERROR_OK;
}
 
static int dmem_dp_q_write(struct adiv5_dap *dap, unsigned int reg, uint32_t data)
{
    return ERROR_OK;
}
 
static int dmem_ap_q_read(struct adiv5_ap *ap, unsigned int reg, uint32_t *data)
{
    unsigned int idx;
 
    if (is_adiv6(ap->dap)) {
        static bool error_flagged;
 
        if (!error_flagged)
            LOG_ERROR("ADIv6 dap not supported by dmem dap-direct mode");
 
        error_flagged = true;
 
        return ERROR_FAIL;
    }
 
    if (dmem_is_emulated_ap(ap, &idx))
        return dmem_emu_ap_q_read(idx, reg, data);
 
    *data = dmem_get_ap_reg(ap, reg);
 
    return ERROR_OK;
}
 
static int dmem_ap_q_write(struct adiv5_ap *ap, unsigned int reg, uint32_t data)
{
    unsigned int idx;
 
    if (is_adiv6(ap->dap)) {
        static bool error_flagged;
 
        if (!error_flagged)
            LOG_ERROR("ADIv6 dap not supported by dmem dap-direct mode");
 
        error_flagged = true;
 
        return ERROR_FAIL;
    }
 
    if (dmem_is_emulated_ap(ap, &idx))
        return dmem_emu_ap_q_write(idx, reg, data);
 
    dmem_set_ap_reg(ap, reg, data);
 
    return ERROR_OK;
}
 
static int dmem_ap_q_abort(struct adiv5_dap *dap, uint8_t *ack)
{
    return ERROR_OK;
}
 
static int dmem_dp_run(struct adiv5_dap *dap)
{
    int retval = dmem_dap_retval;
 
    /* Clear the error code. */
    dmem_dap_retval = ERROR_OK;
 
    return retval;
}
 
static int dmem_connect(struct adiv5_dap *dap)
{
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_dap_device_command)
{
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    free(dmem_dev_path);
    dmem_dev_path = strdup(CMD_ARGV[0]);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_dap_base_address_command)
{
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    COMMAND_PARSE_NUMBER(u64, CMD_ARGV[0], dmem_dap_base_address);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_dap_max_aps_command)
{
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], dmem_dap_max_aps);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_dap_ap_offset_command)
{
    if (CMD_ARGC != 1)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    COMMAND_PARSE_NUMBER(u32, CMD_ARGV[0], dmem_dap_ap_offset);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_emu_base_address_command)
{
    if (CMD_ARGC != 2)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    COMMAND_PARSE_NUMBER(u64, CMD_ARGV[0], dmem_emu_base_address);
    COMMAND_PARSE_NUMBER(u64, CMD_ARGV[1], dmem_emu_size);
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_emu_ap_list_command)
{
    uint64_t em_ap;
 
    if (CMD_ARGC < 1 || CMD_ARGC > DMEM_MAX_EMULATE_APS)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    for (unsigned int i = 0; i < CMD_ARGC; i++) {
        COMMAND_PARSE_NUMBER(u64, CMD_ARGV[i], em_ap);
        dmem_emu_ap_list[i].ap_num = em_ap;
    }
 
    dmem_emu_ap_count = CMD_ARGC;
 
    return ERROR_OK;
}
 
COMMAND_HANDLER(dmem_dap_config_info_command)
{
    if (CMD_ARGC != 0)
        return ERROR_COMMAND_SYNTAX_ERROR;
 
    command_print(CMD, "dmem (Direct Memory) AP Adapter Configuration:");
    command_print(CMD, " Device       : %s",
                  dmem_dev_path ? dmem_dev_path : DMEM_DEV_PATH_DEFAULT);
    command_print(CMD, " Base Address : 0x%" PRIx64, dmem_dap_base_address);
    command_print(CMD, " Max APs      : %u", dmem_dap_max_aps);
    command_print(CMD, " AP offset    : 0x%08" PRIx32, dmem_dap_ap_offset);
    command_print(CMD, " Emulated AP Count : %u", dmem_emu_ap_count);
 
    if (dmem_emu_ap_count) {
        command_print(CMD, " Emulated AP details:");
        command_print(CMD, " Emulated address  : 0x%" PRIx64, dmem_emu_base_address);
        command_print(CMD, " Emulated size     : 0x%" PRIx64, dmem_emu_size);
        for (unsigned int i = 0; i < dmem_emu_ap_count; i++)
            command_print(CMD, " Emulated AP [%u]  : %" PRIx64, i,
                      dmem_emu_ap_list[i].ap_num);
    }
    return ERROR_OK;
}
 
static const struct command_registration dmem_dap_subcommand_handlers[] = {
    {
        .name = "info",
        .handler = dmem_dap_config_info_command,
        .mode = COMMAND_ANY,
        .help = "print the config info",
        .usage = "",
    },
    {
        .name = "device",
        .handler = dmem_dap_device_command,
        .mode = COMMAND_CONFIG,
        .help = "set the dmem memory access device (default: /dev/mem)",
        .usage = "device_path",
    },
    {
        .name = "base_address",
        .handler = dmem_dap_base_address_command,
        .mode = COMMAND_CONFIG,
        .help = "set the dmem dap AP memory map base address",
        .usage = "base_address",
    },
    {
        .name = "ap_address_offset",
        .handler = dmem_dap_ap_offset_command,
        .mode = COMMAND_CONFIG,
        .help = "set the offsets of each ap index",
        .usage = "offset_address",
    },
    {
        .name = "max_aps",
        .handler = dmem_dap_max_aps_command,
        .mode = COMMAND_CONFIG,
        .help = "set the maximum number of APs this will support",
        .usage = "n",
    },
    {
        .name = "emu_ap_list",
        .handler = dmem_emu_ap_list_command,
        .mode = COMMAND_CONFIG,
        .help = "set the list of AP indices to be emulated (upto max)",
        .usage = "n",
    },
    {
        .name = "emu_base_address_range",
        .handler = dmem_emu_base_address_command,
        .mode = COMMAND_CONFIG,
        .help = "set the base address and size of emulated AP range (all emulated APs access this range)",
        .usage = "base_address address_window_size",
    },
    COMMAND_REGISTRATION_DONE
};
 
static const struct command_registration dmem_dap_command_handlers[] = {
    {
        .name = "dmem",
        .mode = COMMAND_ANY,
        .help = "Perform dmem (Direct Memory) DAP management and configuration",
        .chain = dmem_dap_subcommand_handlers,
        .usage = "",
    },
    COMMAND_REGISTRATION_DONE
};
 
static int dmem_dap_init(void)
{
    char *path = dmem_dev_path ? dmem_dev_path : DMEM_DEV_PATH_DEFAULT;
    uint32_t dmem_total_memory_window_size;
    long page_size = sysconf(_SC_PAGESIZE);
    size_t dmem_mapped_start, dmem_mapped_end;
    long start_delta;
    int dmem_fd;
 
    if (!dmem_dap_base_address) {
        LOG_ERROR("dmem DAP Base address NOT set? value is 0");
        return ERROR_FAIL;
    }
 
    dmem_fd = open(path, O_RDWR | O_SYNC);
    if (dmem_fd == -1) {
        LOG_ERROR("Unable to open %s", path);
        return ERROR_FAIL;
    }
 
    dmem_total_memory_window_size = (dmem_dap_max_aps + 1) * dmem_dap_ap_offset;
 
    dmem_mapped_start = dmem_dap_base_address;
    dmem_mapped_end = dmem_dap_base_address + dmem_total_memory_window_size;
     /* mmap() requires page aligned offsets */
    dmem_mapped_start = ALIGN_DOWN(dmem_mapped_start, page_size);
    dmem_mapped_end = ALIGN_UP(dmem_mapped_end, page_size);
 
    dmem_mapped_size = dmem_mapped_end - dmem_mapped_start;
    start_delta = dmem_mapped_start - dmem_dap_base_address;
 
    dmem_map_base = mmap(NULL,
                         dmem_mapped_size,
                         (PROT_READ | PROT_WRITE),
                         MAP_SHARED, dmem_fd,
                         dmem_mapped_start);
    if (dmem_map_base == MAP_FAILED) {
        LOG_ERROR("Mapping address 0x%zx for 0x%zx bytes failed!",
            dmem_mapped_start, dmem_mapped_size);
        goto error_fail;
    }
 
    dmem_virt_base_addr = (void *)((uintptr_t)dmem_map_base + start_delta);
 
    /* Lets Map the emulated address if necessary */
    if (dmem_emu_ap_count) {
        dmem_mapped_start = dmem_emu_base_address;
        dmem_mapped_end = dmem_emu_base_address + dmem_emu_size;
        /* mmap() requires page aligned offsets */
        dmem_mapped_start = ALIGN_DOWN(dmem_mapped_start, page_size);
        dmem_mapped_end = ALIGN_UP(dmem_mapped_end, page_size);
 
        dmem_emu_mapped_size = dmem_mapped_end - dmem_mapped_start;
        start_delta = dmem_mapped_start - dmem_emu_base_address;
 
        dmem_emu_map_base = mmap(NULL,
                                       dmem_emu_mapped_size,
                                       (PROT_READ | PROT_WRITE),
                                       MAP_SHARED, dmem_fd,
                                       dmem_mapped_start);
        if (dmem_emu_map_base == MAP_FAILED) {
            LOG_ERROR("Mapping EMU address 0x%" PRIx64 " for 0x%" PRIx64 " bytes failed!",
                      dmem_emu_base_address, dmem_emu_size);
            goto error_fail;
        }
        dmem_emu_virt_base_addr = (void *)((uintptr_t)dmem_emu_map_base +
                                           start_delta);
    }
 
    close(dmem_fd);
    return ERROR_OK;
 
error_fail:
    close(dmem_fd);
    return ERROR_FAIL;
}
 
static int dmem_dap_quit(void)
{
    if (munmap(dmem_map_base, dmem_mapped_size) == -1)
        LOG_ERROR("%s: Failed to unmap mapped memory!", __func__);
 
    if (dmem_emu_ap_count
        && munmap(dmem_emu_map_base, dmem_emu_mapped_size) == -1)
        LOG_ERROR("%s: Failed to unmap emu mapped memory!", __func__);
 
    return ERROR_OK;
}
 
static int dmem_dap_reset(int req_trst, int req_srst)
{
    return ERROR_OK;
}
 
static int dmem_dap_speed(int speed)
{
    return ERROR_OK;
}
 
static int dmem_dap_khz(int khz, int *jtag_speed)
{
    *jtag_speed = khz;
    return ERROR_OK;
}
 
static int dmem_dap_speed_div(int speed, int *khz)
{
    *khz = speed;
    return ERROR_OK;
}
 
/* DAP operations. */
static const struct dap_ops dmem_dap_ops = {
    .connect = dmem_connect,
    .queue_dp_read = dmem_dp_q_read,
    .queue_dp_write = dmem_dp_q_write,
    .queue_ap_read = dmem_ap_q_read,
    .queue_ap_write = dmem_ap_q_write,
    .queue_ap_abort = dmem_ap_q_abort,
    .run = dmem_dp_run,
};
 
struct adapter_driver dmem_dap_adapter_driver = {
    .name = "dmem",
    .transport_ids = TRANSPORT_DAPDIRECT_SWD,
    .transport_preferred_id = TRANSPORT_DAPDIRECT_SWD,
    .commands = dmem_dap_command_handlers,
 
    .init = dmem_dap_init,
    .quit = dmem_dap_quit,
    .reset = dmem_dap_reset,
    .speed = dmem_dap_speed,
    .khz = dmem_dap_khz,
    .speed_div = dmem_dap_speed_div,
 
    .dap_swd_ops = &dmem_dap_ops,
};