// SPDX-License-Identifier: GPL-2.0
/*
 * Management Complex (MC) userspace support
 *
 * Copyright 2021 NXP
 *
 */

#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>

#include "fsl-mc-private.h"

struct uapi_priv_data {
        struct fsl_mc_uapi *uapi;
        struct fsl_mc_io *mc_io;
};

struct fsl_mc_cmd_desc {
        u16 cmdid_value;
        u16 cmdid_mask;
        int size;
        bool token;
        int flags;
};

#define FSL_MC_CHECK_MODULE_ID          BIT(0)
#define FSL_MC_CAP_NET_ADMIN_NEEDED     BIT(1)

enum fsl_mc_cmd_index {
        DPDBG_DUMP = 0,
        DPDBG_SET,
        DPRC_GET_CONTAINER_ID,
        DPRC_CREATE_CONT,
        DPRC_DESTROY_CONT,
        DPRC_ASSIGN,
        DPRC_UNASSIGN,
        DPRC_GET_OBJ_COUNT,
        DPRC_GET_OBJ,
        DPRC_GET_RES_COUNT,
        DPRC_GET_RES_IDS,
        DPRC_SET_OBJ_LABEL,
        DPRC_SET_LOCKED,
        DPRC_CONNECT,
        DPRC_DISCONNECT,
        DPRC_GET_POOL,
        DPRC_GET_POOL_COUNT,
        DPRC_GET_CONNECTION,
        DPRC_GET_MEM,
        DPCI_GET_LINK_STATE,
        DPCI_GET_PEER_ATTR,
        DPAIOP_GET_SL_VERSION,
        DPAIOP_GET_STATE,
        DPMNG_GET_VERSION,
        DPSECI_GET_TX_QUEUE,
        DPMAC_GET_COUNTER,
        DPMAC_GET_MAC_ADDR,
        DPNI_SET_PRIM_MAC,
        DPNI_GET_PRIM_MAC,
        DPNI_GET_STATISTICS,
        DPNI_GET_LINK_STATE,
        DPNI_GET_MAX_FRAME_LENGTH,
        DPSW_GET_TAILDROP,
        DPSW_SET_TAILDROP,
        DPSW_IF_GET_COUNTER,
        DPSW_IF_GET_MAX_FRAME_LENGTH,
        DPDMUX_GET_COUNTER,
        DPDMUX_IF_GET_MAX_FRAME_LENGTH,
        GET_ATTR,
        GET_IRQ_MASK,
        GET_IRQ_STATUS,
        CLOSE,
        OPEN,
        GET_API_VERSION,
        DESTROY,
        CREATE,
};

static struct fsl_mc_cmd_desc fsl_mc_accepted_cmds[] = {
        [DPDBG_DUMP] = {
                .cmdid_value = 0x1300,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 28,
        },
        [DPDBG_SET] = {
                .cmdid_value = 0x1400,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 28,
        },
        [DPRC_GET_CONTAINER_ID] = {
                .cmdid_value = 0x8300,
                .cmdid_mask = 0xFFF0,
                .token = false,
                .size = 8,
        },
        [DPRC_CREATE_CONT] = {
                .cmdid_value = 0x1510,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 40,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_DESTROY_CONT] = {
                .cmdid_value = 0x1520,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 12,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_ASSIGN] = {
                .cmdid_value = 0x1570,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 40,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_UNASSIGN] = {
                .cmdid_value = 0x1580,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 40,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_GET_OBJ_COUNT] = {
                .cmdid_value = 0x1590,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 16,
        },
        [DPRC_GET_OBJ] = {
                .cmdid_value = 0x15A0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 12,
        },
        [DPRC_GET_RES_COUNT] = {
                .cmdid_value = 0x15B0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 32,
        },
        [DPRC_GET_RES_IDS] = {
                .cmdid_value = 0x15C0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 40,
        },
        [DPRC_SET_OBJ_LABEL] = {
                .cmdid_value = 0x1610,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 48,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_SET_LOCKED] = {
                .cmdid_value = 0x16B0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 16,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_CONNECT] = {
                .cmdid_value = 0x1670,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 56,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_DISCONNECT] = {
                .cmdid_value = 0x1680,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 32,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPRC_GET_POOL] = {
                .cmdid_value = 0x1690,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 12,
        },
        [DPRC_GET_POOL_COUNT] = {
                .cmdid_value = 0x16A0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPRC_GET_CONNECTION] = {
                .cmdid_value = 0x16C0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 32,
        },
        [DPRC_GET_MEM] = {
                .cmdid_value = 0x16D0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 12,
        },

        [DPCI_GET_LINK_STATE] = {
                .cmdid_value = 0x0E10,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPCI_GET_PEER_ATTR] = {
                .cmdid_value = 0x0E20,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPAIOP_GET_SL_VERSION] = {
                .cmdid_value = 0x2820,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPAIOP_GET_STATE] = {
                .cmdid_value = 0x2830,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPMNG_GET_VERSION] = {
                .cmdid_value = 0x8310,
                .cmdid_mask = 0xFFF0,
                .token = false,
                .size = 8,
        },
        [DPSECI_GET_TX_QUEUE] = {
                .cmdid_value = 0x1970,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 14,
        },
        [DPMAC_GET_COUNTER] = {
                .cmdid_value = 0x0c40,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 9,
        },
        [DPMAC_GET_MAC_ADDR] = {
                .cmdid_value = 0x0c50,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPNI_SET_PRIM_MAC] = {
                .cmdid_value = 0x2240,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 16,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPNI_GET_PRIM_MAC] = {
                .cmdid_value = 0x2250,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPNI_GET_STATISTICS] = {
                .cmdid_value = 0x25D0,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 10,
        },
        [DPNI_GET_LINK_STATE] = {
                .cmdid_value = 0x2150,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPNI_GET_MAX_FRAME_LENGTH] = {
                .cmdid_value = 0x2170,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [DPSW_GET_TAILDROP] = {
                .cmdid_value = 0x0A90,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 14,
        },
        [DPSW_SET_TAILDROP] = {
                .cmdid_value = 0x0A80,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 24,
                .flags = FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [DPSW_IF_GET_COUNTER] = {
                .cmdid_value = 0x0340,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 11,
        },
        [DPSW_IF_GET_MAX_FRAME_LENGTH] = {
                .cmdid_value = 0x0450,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 10,
        },
        [DPDMUX_GET_COUNTER] = {
                .cmdid_value = 0x0b20,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 11,
        },
        [DPDMUX_IF_GET_MAX_FRAME_LENGTH] = {
                .cmdid_value = 0x0a20,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 10,
        },
        [GET_ATTR] = {
                .cmdid_value = 0x0040,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },
        [GET_IRQ_MASK] = {
                .cmdid_value = 0x0150,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 13,
        },
        [GET_IRQ_STATUS] = {
                .cmdid_value = 0x0160,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 13,
        },
        [CLOSE] = {
                .cmdid_value = 0x8000,
                .cmdid_mask = 0xFFF0,
                .token = true,
                .size = 8,
        },

        /* Common commands amongst all types of objects. Must be checked last. */
        [OPEN] = {
                .cmdid_value = 0x8000,
                .cmdid_mask = 0xFC00,
                .token = false,
                .size = 12,
                .flags = FSL_MC_CHECK_MODULE_ID,
        },
        [GET_API_VERSION] = {
                .cmdid_value = 0xA000,
                .cmdid_mask = 0xFC00,
                .token = false,
                .size = 8,
                .flags = FSL_MC_CHECK_MODULE_ID,
        },
        [DESTROY] = {
                .cmdid_value = 0x9800,
                .cmdid_mask = 0xFC00,
                .token = true,
                .size = 12,
                .flags = FSL_MC_CHECK_MODULE_ID | FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
        [CREATE] = {
                .cmdid_value = 0x9000,
                .cmdid_mask = 0xFC00,
                .token = true,
                .size = 64,
                .flags = FSL_MC_CHECK_MODULE_ID | FSL_MC_CAP_NET_ADMIN_NEEDED,
        },
};

#define FSL_MC_NUM_ACCEPTED_CMDS ARRAY_SIZE(fsl_mc_accepted_cmds)

#define FSL_MC_MAX_MODULE_ID 0x10

static int fsl_mc_command_check(struct fsl_mc_device *mc_dev,
                                struct fsl_mc_command *mc_cmd)
{
        struct fsl_mc_cmd_desc *desc = NULL;
        int mc_cmd_max_size, i;
        bool token_provided;
        u16 cmdid, module_id;
        char *mc_cmd_end;
        char sum = 0;

        /* Check if this is an accepted MC command */
        cmdid = mc_cmd_hdr_read_cmdid(mc_cmd);
        for (i = 0; i < FSL_MC_NUM_ACCEPTED_CMDS; i++) {
                desc = &fsl_mc_accepted_cmds[i];
                if ((cmdid & desc->cmdid_mask) == desc->cmdid_value)
                        break;
        }
        if (i == FSL_MC_NUM_ACCEPTED_CMDS) {
                dev_err(&mc_dev->dev, "MC command 0x%04x: cmdid not accepted\n", cmdid);
                return -EACCES;
        }

        /* Check if the size of the command is honored. Anything beyond the
         * last valid byte of the command should be zeroed.
         */
        mc_cmd_max_size = sizeof(*mc_cmd);
        mc_cmd_end = ((char *)mc_cmd) + desc->size;
        for (i = desc->size; i < mc_cmd_max_size; i++)
                sum |= *mc_cmd_end++;
        if (sum) {
                dev_err(&mc_dev->dev, "MC command 0x%04x: garbage beyond max size of %d bytes!\n",
                        cmdid, desc->size);
                return -EACCES;
        }

        /* Some MC commands request a token to be passed so that object
         * identification is possible. Check if the token passed in the command
         * is as expected.
         */
        token_provided = mc_cmd_hdr_read_token(mc_cmd) ? true : false;
        if (token_provided != desc->token) {
                dev_err(&mc_dev->dev, "MC command 0x%04x: token 0x%04x is invalid!\n",
                        cmdid, mc_cmd_hdr_read_token(mc_cmd));
                return -EACCES;
        }

        /* If needed, check if the module ID passed is valid */
        if (desc->flags & FSL_MC_CHECK_MODULE_ID) {
                /* The module ID is represented by bits [4:9] from the cmdid */
                module_id = (cmdid & GENMASK(9, 4)) >> 4;
                if (module_id == 0 || module_id > FSL_MC_MAX_MODULE_ID) {
                        dev_err(&mc_dev->dev, "MC command 0x%04x: unknown module ID 0x%x\n",
                                cmdid, module_id);
                        return -EACCES;
                }
        }

        /* Some commands alter how hardware resources are managed. For these
         * commands, check for CAP_NET_ADMIN.
         */
        if (desc->flags & FSL_MC_CAP_NET_ADMIN_NEEDED) {
                if (!capable(CAP_NET_ADMIN)) {
                        dev_err(&mc_dev->dev, "MC command 0x%04x: needs CAP_NET_ADMIN!\n",
                                cmdid);
                        return -EPERM;
                }
        }

        return 0;
}

static int fsl_mc_uapi_send_command(struct fsl_mc_device *mc_dev, unsigned long arg,
                                    struct fsl_mc_io *mc_io)
{
        struct fsl_mc_command mc_cmd;
        int error;

        error = copy_from_user(&mc_cmd, (void __user *)arg, sizeof(mc_cmd));
        if (error)
                return -EFAULT;

        error = fsl_mc_command_check(mc_dev, &mc_cmd);
        if (error)
                return error;

        error = mc_send_command(mc_io, &mc_cmd);
        if (error)
                return error;

        error = copy_to_user((void __user *)arg, &mc_cmd, sizeof(mc_cmd));
        if (error)
                return -EFAULT;

        return 0;
}

static int fsl_mc_uapi_dev_open(struct inode *inode, struct file *filep)
{
        struct fsl_mc_device *root_mc_device;
        struct uapi_priv_data *priv_data;
        struct fsl_mc_io *dynamic_mc_io;
        struct fsl_mc_uapi *mc_uapi;
        struct fsl_mc_bus *mc_bus;
        int error;

        priv_data = kzalloc_obj(*priv_data);
        if (!priv_data)
                return -ENOMEM;

        mc_uapi = container_of(filep->private_data, struct fsl_mc_uapi, misc);
        mc_bus = container_of(mc_uapi, struct fsl_mc_bus, uapi_misc);
        root_mc_device = &mc_bus->mc_dev;

        mutex_lock(&mc_uapi->mutex);

        if (!mc_uapi->local_instance_in_use) {
                priv_data->mc_io = mc_uapi->static_mc_io;
                mc_uapi->local_instance_in_use = 1;
        } else {
                error = fsl_mc_portal_allocate(root_mc_device, 0,
                                               &dynamic_mc_io);
                if (error) {
                        dev_dbg(&root_mc_device->dev,
                                "Could not allocate MC portal\n");
                        goto error_portal_allocate;
                }

                priv_data->mc_io = dynamic_mc_io;
        }
        priv_data->uapi = mc_uapi;
        filep->private_data = priv_data;

        mutex_unlock(&mc_uapi->mutex);

        return 0;

error_portal_allocate:
        mutex_unlock(&mc_uapi->mutex);
        kfree(priv_data);

        return error;
}

static int fsl_mc_uapi_dev_release(struct inode *inode, struct file *filep)
{
        struct uapi_priv_data *priv_data;
        struct fsl_mc_uapi *mc_uapi;
        struct fsl_mc_io *mc_io;

        priv_data = filep->private_data;
        mc_uapi = priv_data->uapi;
        mc_io = priv_data->mc_io;

        mutex_lock(&mc_uapi->mutex);

        if (mc_io == mc_uapi->static_mc_io)
                mc_uapi->local_instance_in_use = 0;
        else
                fsl_mc_portal_free(mc_io);

        kfree(filep->private_data);
        filep->private_data =  NULL;

        mutex_unlock(&mc_uapi->mutex);

        return 0;
}

static long fsl_mc_uapi_dev_ioctl(struct file *file,
                                  unsigned int cmd,
                                  unsigned long arg)
{
        struct uapi_priv_data *priv_data = file->private_data;
        struct fsl_mc_device *root_mc_device;
        struct fsl_mc_bus *mc_bus;
        int error;

        mc_bus = container_of(priv_data->uapi, struct fsl_mc_bus, uapi_misc);
        root_mc_device = &mc_bus->mc_dev;

        switch (cmd) {
        case FSL_MC_SEND_MC_COMMAND:
                error = fsl_mc_uapi_send_command(root_mc_device, arg, priv_data->mc_io);
                break;
        default:
                dev_dbg(&root_mc_device->dev, "unexpected ioctl call number\n");
                error = -EINVAL;
        }

        return error;
}

static const struct file_operations fsl_mc_uapi_dev_fops = {
        .owner = THIS_MODULE,
        .open = fsl_mc_uapi_dev_open,
        .release = fsl_mc_uapi_dev_release,
        .unlocked_ioctl = fsl_mc_uapi_dev_ioctl,
};

int fsl_mc_uapi_create_device_file(struct fsl_mc_bus *mc_bus)
{
        struct fsl_mc_device *mc_dev = &mc_bus->mc_dev;
        struct fsl_mc_uapi *mc_uapi = &mc_bus->uapi_misc;
        int error;

        mc_uapi->misc.minor = MISC_DYNAMIC_MINOR;
        mc_uapi->misc.name = dev_name(&mc_dev->dev);
        mc_uapi->misc.fops = &fsl_mc_uapi_dev_fops;

        error = misc_register(&mc_uapi->misc);
        if (error)
                return error;

        mc_uapi->static_mc_io = mc_bus->mc_dev.mc_io;

        mutex_init(&mc_uapi->mutex);

        return 0;
}

void fsl_mc_uapi_remove_device_file(struct fsl_mc_bus *mc_bus)
{
        misc_deregister(&mc_bus->uapi_misc.misc);
}