/*
 * Copyright (C) 2015-2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
 * nfp_nsp.c
 * Author: Jakub Kicinski <jakub.kicinski@netronome.com>
 *         Jason McMullan <jason.mcmullan@netronome.com>
 */

#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/firmware.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/sizes.h>
#include <linux/slab.h>

#define NFP_SUBSYS "nfp_nsp"

#include "nfp.h"
#include "nfp_cpp.h"
#include "nfp_nsp.h"

#define NFP_NSP_TIMEOUT_DEFAULT 30
#define NFP_NSP_TIMEOUT_BOOT    30

/* Offsets relative to the CSR base */
#define NSP_STATUS              0x00
#define   NSP_STATUS_MAGIC      GENMASK_ULL(63, 48)
#define   NSP_STATUS_MAJOR      GENMASK_ULL(47, 44)
#define   NSP_STATUS_MINOR      GENMASK_ULL(43, 32)
#define   NSP_STATUS_CODE       GENMASK_ULL(31, 16)
#define   NSP_STATUS_RESULT     GENMASK_ULL(15, 8)
#define   NSP_STATUS_BUSY       BIT_ULL(0)

#define NSP_COMMAND             0x08
#define   NSP_COMMAND_OPTION    GENMASK_ULL(63, 32)
#define   NSP_COMMAND_CODE      GENMASK_ULL(31, 16)
#define   NSP_COMMAND_START     BIT_ULL(0)

/* CPP address to retrieve the data from */
#define NSP_BUFFER              0x10
#define   NSP_BUFFER_CPP        GENMASK_ULL(63, 40)
#define   NSP_BUFFER_ADDRESS    GENMASK_ULL(39, 0)

#define NSP_DFLT_BUFFER         0x18
#define   NSP_DFLT_BUFFER_CPP   GENMASK_ULL(63, 40)
#define   NSP_DFLT_BUFFER_ADDRESS       GENMASK_ULL(39, 0)

#define NSP_DFLT_BUFFER_CONFIG  0x20
#define   NSP_DFLT_BUFFER_SIZE_MB       GENMASK_ULL(7, 0)

#define NSP_MAGIC               0xab10
#define NSP_MAJOR               0
#define NSP_MINOR               8

#define NSP_CODE_MAJOR          GENMASK(15, 12)
#define NSP_CODE_MINOR          GENMASK(11, 0)

enum nfp_nsp_cmd {
        SPCODE_NOOP             = 0, /* No operation */
        SPCODE_SOFT_RESET       = 1, /* Soft reset the NFP */
        SPCODE_FW_DEFAULT       = 2, /* Load default (UNDI) FW */
        SPCODE_PHY_INIT         = 3, /* Initialize the PHY */
        SPCODE_MAC_INIT         = 4, /* Initialize the MAC */
        SPCODE_PHY_RXADAPT      = 5, /* Re-run PHY RX Adaptation */
        SPCODE_FW_LOAD          = 6, /* Load fw from buffer, len in option */
        SPCODE_ETH_RESCAN       = 7, /* Rescan ETHs, write ETH_TABLE to buf */
        SPCODE_ETH_CONTROL      = 8, /* Update media config from buffer */
        SPCODE_NSP_WRITE_FLASH  = 11, /* Load and flash image from buffer */
        SPCODE_NSP_SENSORS      = 12, /* Read NSP sensor(s) */
        SPCODE_NSP_IDENTIFY     = 13, /* Read NSP version */
};

static const struct {
        int code;
        const char *msg;
} nsp_errors[] = {
        { 6010, "could not map to phy for port" },
        { 6011, "not an allowed rate/lanes for port" },
        { 6012, "not an allowed rate/lanes for port" },
        { 6013, "high/low error, change other port first" },
        { 6014, "config not found in flash" },
};

struct nfp_nsp {
        struct nfp_cpp *cpp;
        struct nfp_resource *res;
        struct {
                u16 major;
                u16 minor;
        } ver;

        /* Eth table config state */
        bool modified;
        unsigned int idx;
        void *entries;
};

struct nfp_cpp *nfp_nsp_cpp(struct nfp_nsp *state)
{
        return state->cpp;
}

bool nfp_nsp_config_modified(struct nfp_nsp *state)
{
        return state->modified;
}

void nfp_nsp_config_set_modified(struct nfp_nsp *state, bool modified)
{
        state->modified = modified;
}

void *nfp_nsp_config_entries(struct nfp_nsp *state)
{
        return state->entries;
}

unsigned int nfp_nsp_config_idx(struct nfp_nsp *state)
{
        return state->idx;
}

void
nfp_nsp_config_set_state(struct nfp_nsp *state, void *entries, unsigned int idx)
{
        state->entries = entries;
        state->idx = idx;
}

void nfp_nsp_config_clear_state(struct nfp_nsp *state)
{
        state->entries = NULL;
        state->idx = 0;
}

static void nfp_nsp_print_extended_error(struct nfp_nsp *state, u32 ret_val)
{
        int i;

        if (!ret_val)
                return;

        for (i = 0; i < ARRAY_SIZE(nsp_errors); i++)
                if (ret_val == nsp_errors[i].code)
                        nfp_err(state->cpp, "err msg: %s\n", nsp_errors[i].msg);
}

static int nfp_nsp_check(struct nfp_nsp *state)
{
        struct nfp_cpp *cpp = state->cpp;
        u64 nsp_status, reg;
        u32 nsp_cpp;
        int err;

        nsp_cpp = nfp_resource_cpp_id(state->res);
        nsp_status = nfp_resource_address(state->res) + NSP_STATUS;

        err = nfp_cpp_readq(cpp, nsp_cpp, nsp_status, &reg);
        if (err < 0)
                return err;

        if (FIELD_GET(NSP_STATUS_MAGIC, reg) != NSP_MAGIC) {
                nfp_err(cpp, "Cannot detect NFP Service Processor\n");
                return -ENODEV;
        }

        state->ver.major = FIELD_GET(NSP_STATUS_MAJOR, reg);
        state->ver.minor = FIELD_GET(NSP_STATUS_MINOR, reg);

        if (state->ver.major != NSP_MAJOR || state->ver.minor < NSP_MINOR) {
                nfp_err(cpp, "Unsupported ABI %hu.%hu\n",
                        state->ver.major, state->ver.minor);
                return -EINVAL;
        }

        if (reg & NSP_STATUS_BUSY) {
                nfp_err(cpp, "Service processor busy!\n");
                return -EBUSY;
        }

        return 0;
}

/**
 * nfp_nsp_open() - Prepare for communication and lock the NSP resource.
 * @cpp:        NFP CPP Handle
 */
struct nfp_nsp *nfp_nsp_open(struct nfp_cpp *cpp)
{
        struct nfp_resource *res;
        struct nfp_nsp *state;
        int err;

        res = nfp_resource_acquire(cpp, NFP_RESOURCE_NSP);
        if (IS_ERR(res))
                return (void *)res;

        state = kzalloc(sizeof(*state), GFP_KERNEL);
        if (!state) {
                nfp_resource_release(res);
                return ERR_PTR(-ENOMEM);
        }
        state->cpp = cpp;
        state->res = res;

        err = nfp_nsp_check(state);
        if (err) {
                nfp_nsp_close(state);
                return ERR_PTR(err);
        }

        return state;
}

/**
 * nfp_nsp_close() - Clean up and unlock the NSP resource.
 * @state:      NFP SP state
 */
void nfp_nsp_close(struct nfp_nsp *state)
{
        nfp_resource_release(state->res);
        kfree(state);
}

u16 nfp_nsp_get_abi_ver_major(struct nfp_nsp *state)
{
        return state->ver.major;
}

u16 nfp_nsp_get_abi_ver_minor(struct nfp_nsp *state)
{
        return state->ver.minor;
}

static int
nfp_nsp_wait_reg(struct nfp_cpp *cpp, u64 *reg, u32 nsp_cpp, u64 addr,
                 u64 mask, u64 val, u32 timeout_sec)
{
        const unsigned long wait_until = jiffies + timeout_sec * HZ;
        int err;

        for (;;) {
                const unsigned long start_time = jiffies;

                err = nfp_cpp_readq(cpp, nsp_cpp, addr, reg);
                if (err < 0)
                        return err;

                if ((*reg & mask) == val)
                        return 0;

                msleep(25);

                if (time_after(start_time, wait_until))
                        return -ETIMEDOUT;
        }
}

/**
 * __nfp_nsp_command() - Execute a command on the NFP Service Processor
 * @state:      NFP SP state
 * @code:       NFP SP Command Code
 * @option:     NFP SP Command Argument
 * @buff_cpp:   NFP SP Buffer CPP Address info
 * @buff_addr:  NFP SP Buffer Host address
 * @timeout_sec:Timeout value to wait for completion in seconds
 *
 * Return: 0 for success with no result
 *
 *       positive value for NSP completion with a result code
 *
 *      -EAGAIN if the NSP is not yet present
 *      -ENODEV if the NSP is not a supported model
 *      -EBUSY if the NSP is stuck
 *      -EINTR if interrupted while waiting for completion
 *      -ETIMEDOUT if the NSP took longer than @timeout_sec seconds to complete
 */
static int
__nfp_nsp_command(struct nfp_nsp *state, u16 code, u32 option, u32 buff_cpp,
                  u64 buff_addr, u32 timeout_sec)
{
        u64 reg, ret_val, nsp_base, nsp_buffer, nsp_status, nsp_command;
        struct nfp_cpp *cpp = state->cpp;
        u32 nsp_cpp;
        int err;

        nsp_cpp = nfp_resource_cpp_id(state->res);
        nsp_base = nfp_resource_address(state->res);
        nsp_status = nsp_base + NSP_STATUS;
        nsp_command = nsp_base + NSP_COMMAND;
        nsp_buffer = nsp_base + NSP_BUFFER;

        err = nfp_nsp_check(state);
        if (err)
                return err;

        if (!FIELD_FIT(NSP_BUFFER_CPP, buff_cpp >> 8) ||
            !FIELD_FIT(NSP_BUFFER_ADDRESS, buff_addr)) {
                nfp_err(cpp, "Host buffer out of reach %08x %016llx\n",
                        buff_cpp, buff_addr);
                return -EINVAL;
        }

        err = nfp_cpp_writeq(cpp, nsp_cpp, nsp_buffer,
                             FIELD_PREP(NSP_BUFFER_CPP, buff_cpp >> 8) |
                             FIELD_PREP(NSP_BUFFER_ADDRESS, buff_addr));
        if (err < 0)
                return err;

        err = nfp_cpp_writeq(cpp, nsp_cpp, nsp_command,
                             FIELD_PREP(NSP_COMMAND_OPTION, option) |
                             FIELD_PREP(NSP_COMMAND_CODE, code) |
                             FIELD_PREP(NSP_COMMAND_START, 1));
        if (err < 0)
                return err;

        /* Wait for NSP_COMMAND_START to go to 0 */
        err = nfp_nsp_wait_reg(cpp, &reg, nsp_cpp, nsp_command,
                               NSP_COMMAND_START, 0, NFP_NSP_TIMEOUT_DEFAULT);
        if (err) {
                nfp_err(cpp, "Error %d waiting for code 0x%04x to start\n",
                        err, code);
                return err;
        }

        /* Wait for NSP_STATUS_BUSY to go to 0 */
        err = nfp_nsp_wait_reg(cpp, &reg, nsp_cpp, nsp_status, NSP_STATUS_BUSY,
                               0, timeout_sec);
        if (err) {
                nfp_err(cpp, "Error %d waiting for code 0x%04x to complete\n",
                        err, code);
                return err;
        }

        err = nfp_cpp_readq(cpp, nsp_cpp, nsp_command, &ret_val);
        if (err < 0)
                return err;
        ret_val = FIELD_GET(NSP_COMMAND_OPTION, ret_val);

        err = FIELD_GET(NSP_STATUS_RESULT, reg);
        if (err) {
                nfp_warn(cpp, "Result (error) code set: %d (%d) command: %d\n",
                         -err, (int)ret_val, code);
                nfp_nsp_print_extended_error(state, ret_val);
                return -err;
        }

        return ret_val;
}

static int
nfp_nsp_command(struct nfp_nsp *state, u16 code, u32 option, u32 buff_cpp,
                u64 buff_addr)
{
        return __nfp_nsp_command(state, code, option, buff_cpp, buff_addr,
                                 NFP_NSP_TIMEOUT_DEFAULT);
}

static int
__nfp_nsp_command_buf(struct nfp_nsp *nsp, u16 code, u32 option,
                      const void *in_buf, unsigned int in_size, void *out_buf,
                      unsigned int out_size, u32 timeout_sec)
{
        struct nfp_cpp *cpp = nsp->cpp;
        unsigned int max_size;
        u64 reg, cpp_buf;
        int ret, err;
        u32 cpp_id;

        if (nsp->ver.minor < 13) {
                nfp_err(cpp, "NSP: Code 0x%04x with buffer not supported (ABI %hu.%hu)\n",
                        code, nsp->ver.major, nsp->ver.minor);
                return -EOPNOTSUPP;
        }

        err = nfp_cpp_readq(cpp, nfp_resource_cpp_id(nsp->res),
                            nfp_resource_address(nsp->res) +
                            NSP_DFLT_BUFFER_CONFIG,
                            &reg);
        if (err < 0)
                return err;

        max_size = max(in_size, out_size);
        if (FIELD_GET(NSP_DFLT_BUFFER_SIZE_MB, reg) * SZ_1M < max_size) {
                nfp_err(cpp, "NSP: default buffer too small for command 0x%04x (%llu < %u)\n",
                        code, FIELD_GET(NSP_DFLT_BUFFER_SIZE_MB, reg) * SZ_1M,
                        max_size);
                return -EINVAL;
        }

        err = nfp_cpp_readq(cpp, nfp_resource_cpp_id(nsp->res),
                            nfp_resource_address(nsp->res) +
                            NSP_DFLT_BUFFER,
                            &reg);
        if (err < 0)
                return err;

        cpp_id = FIELD_GET(NSP_DFLT_BUFFER_CPP, reg) << 8;
        cpp_buf = FIELD_GET(NSP_DFLT_BUFFER_ADDRESS, reg);

        if (in_buf && in_size) {
                err = nfp_cpp_write(cpp, cpp_id, cpp_buf, in_buf, in_size);
                if (err < 0)
                        return err;
        }
        /* Zero out remaining part of the buffer */
        if (out_buf && out_size && out_size > in_size) {
                memset(out_buf, 0, out_size - in_size);
                err = nfp_cpp_write(cpp, cpp_id, cpp_buf + in_size,
                                    out_buf, out_size - in_size);
                if (err < 0)
                        return err;
        }

        ret = __nfp_nsp_command(nsp, code, option, cpp_id, cpp_buf,
                                timeout_sec);
        if (ret < 0)
                return ret;

        if (out_buf && out_size) {
                err = nfp_cpp_read(cpp, cpp_id, cpp_buf, out_buf, out_size);
                if (err < 0)
                        return err;
        }

        return ret;
}

static int
nfp_nsp_command_buf(struct nfp_nsp *nsp, u16 code, u32 option,
                    const void *in_buf, unsigned int in_size, void *out_buf,
                    unsigned int out_size)
{
        return __nfp_nsp_command_buf(nsp, code, option, in_buf, in_size,
                                     out_buf, out_size,
                                     NFP_NSP_TIMEOUT_DEFAULT);
}

int nfp_nsp_wait(struct nfp_nsp *state)
{
        const unsigned long wait_until = jiffies + NFP_NSP_TIMEOUT_BOOT * HZ;
        int err;

        nfp_dbg(state->cpp, "Waiting for NSP to respond (%u sec max).\n",
                NFP_NSP_TIMEOUT_BOOT);

        for (;;) {
                const unsigned long start_time = jiffies;

                err = nfp_nsp_command(state, SPCODE_NOOP, 0, 0, 0);
                if (err != -EAGAIN)
                        break;

                if (msleep_interruptible(25)) {
                        err = -ERESTARTSYS;
                        break;
                }

                if (time_after(start_time, wait_until)) {
                        err = -ETIMEDOUT;
                        break;
                }
        }
        if (err)
                nfp_err(state->cpp, "NSP failed to respond %d\n", err);

        return err;
}

int nfp_nsp_device_soft_reset(struct nfp_nsp *state)
{
        return nfp_nsp_command(state, SPCODE_SOFT_RESET, 0, 0, 0);
}

int nfp_nsp_mac_reinit(struct nfp_nsp *state)
{
        return nfp_nsp_command(state, SPCODE_MAC_INIT, 0, 0, 0);
}

int nfp_nsp_load_fw(struct nfp_nsp *state, const struct firmware *fw)
{
        return nfp_nsp_command_buf(state, SPCODE_FW_LOAD, fw->size, fw->data,
                                   fw->size, NULL, 0);
}

int nfp_nsp_write_flash(struct nfp_nsp *state, const struct firmware *fw)
{
        /* The flash time is specified to take a maximum of 70s so we add an
         * additional factor to this spec time.
         */
        u32 timeout_sec = 2.5 * 70;

        return __nfp_nsp_command_buf(state, SPCODE_NSP_WRITE_FLASH, fw->size,
                                     fw->data, fw->size, NULL, 0, timeout_sec);
}

int nfp_nsp_read_eth_table(struct nfp_nsp *state, void *buf, unsigned int size)
{
        return nfp_nsp_command_buf(state, SPCODE_ETH_RESCAN, size, NULL, 0,
                                   buf, size);
}

int nfp_nsp_write_eth_table(struct nfp_nsp *state,
                            const void *buf, unsigned int size)
{
        return nfp_nsp_command_buf(state, SPCODE_ETH_CONTROL, size, buf, size,
                                   NULL, 0);
}

int nfp_nsp_read_identify(struct nfp_nsp *state, void *buf, unsigned int size)
{
        return nfp_nsp_command_buf(state, SPCODE_NSP_IDENTIFY, size, NULL, 0,
                                   buf, size);
}

int nfp_nsp_read_sensors(struct nfp_nsp *state, unsigned int sensor_mask,
                         void *buf, unsigned int size)
{
        return nfp_nsp_command_buf(state, SPCODE_NSP_SENSORS, sensor_mask,
                                   NULL, 0, buf, size);
}