// SPDX-License-Identifier: GPL-2.0-only
/*
 * PS3 BD/DVD/CD-ROM Storage Driver
 *
 * Copyright (C) 2007 Sony Computer Entertainment Inc.
 * Copyright 2007 Sony Corp.
 */

#include <linux/cdrom.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>

#include <asm/lv1call.h>
#include <asm/ps3stor.h>


#define DEVICE_NAME                     "ps3rom"

#define BOUNCE_SIZE                     (64*1024)

#define PS3ROM_MAX_SECTORS              (BOUNCE_SIZE >> 9)


struct ps3rom_private {
        struct ps3_storage_device *dev;
        struct scsi_cmnd *curr_cmd;
};


#define LV1_STORAGE_SEND_ATAPI_COMMAND  (1)

struct lv1_atapi_cmnd_block {
        u8      pkt[32];        /* packet command block           */
        u32     pktlen;         /* should be 12 for ATAPI 8020    */
        u32     blocks;
        u32     block_size;
        u32     proto;          /* transfer mode                  */
        u32     in_out;         /* transfer direction             */
        u64     buffer;         /* parameter except command block */
        u32     arglen;         /* length above                   */
};

enum lv1_atapi_proto {
        NON_DATA_PROTO     = 0,
        PIO_DATA_IN_PROTO  = 1,
        PIO_DATA_OUT_PROTO = 2,
        DMA_PROTO = 3
};

enum lv1_atapi_in_out {
        DIR_WRITE = 0,          /* memory -> device */
        DIR_READ = 1            /* device -> memory */
};


static int ps3rom_sdev_configure(struct scsi_device *scsi_dev,
                                 struct queue_limits *lim)
{
        struct ps3rom_private *priv = shost_priv(scsi_dev->host);
        struct ps3_storage_device *dev = priv->dev;

        dev_dbg(&dev->sbd.core, "%s:%u: id %u, lun %llu, channel %u\n", __func__,
                __LINE__, scsi_dev->id, scsi_dev->lun, scsi_dev->channel);

        /*
         * ATAPI SFF8020 devices use MODE_SENSE_10,
         * so we can prohibit MODE_SENSE_6
         */
        scsi_dev->use_10_for_ms = 1;

        /* we don't support {READ,WRITE}_6 */
        scsi_dev->use_10_for_rw = 1;

        return 0;
}

static int ps3rom_atapi_request(struct ps3_storage_device *dev,
                                struct scsi_cmnd *cmd)
{
        struct lv1_atapi_cmnd_block atapi_cmnd;
        unsigned char opcode = cmd->cmnd[0];
        int res;
        u64 lpar;

        dev_dbg(&dev->sbd.core, "%s:%u: send ATAPI command 0x%02x\n", __func__,
                __LINE__, opcode);

        memset(&atapi_cmnd, 0, sizeof(struct lv1_atapi_cmnd_block));
        memcpy(&atapi_cmnd.pkt, cmd->cmnd, 12);
        atapi_cmnd.pktlen = 12;
        atapi_cmnd.block_size = 1; /* transfer size is block_size * blocks */
        atapi_cmnd.blocks = atapi_cmnd.arglen = scsi_bufflen(cmd);
        atapi_cmnd.buffer = dev->bounce_lpar;

        switch (cmd->sc_data_direction) {
        case DMA_FROM_DEVICE:
                if (scsi_bufflen(cmd) >= CD_FRAMESIZE)
                        atapi_cmnd.proto = DMA_PROTO;
                else
                        atapi_cmnd.proto = PIO_DATA_IN_PROTO;
                atapi_cmnd.in_out = DIR_READ;
                break;

        case DMA_TO_DEVICE:
                if (scsi_bufflen(cmd) >= CD_FRAMESIZE)
                        atapi_cmnd.proto = DMA_PROTO;
                else
                        atapi_cmnd.proto = PIO_DATA_OUT_PROTO;
                atapi_cmnd.in_out = DIR_WRITE;
                scsi_sg_copy_to_buffer(cmd, dev->bounce_buf, dev->bounce_size);
                break;

        default:
                atapi_cmnd.proto = NON_DATA_PROTO;
                break;
        }

        lpar = ps3_mm_phys_to_lpar(__pa(&atapi_cmnd));
        res = lv1_storage_send_device_command(dev->sbd.dev_id,
                                              LV1_STORAGE_SEND_ATAPI_COMMAND,
                                              lpar, sizeof(atapi_cmnd),
                                              atapi_cmnd.buffer,
                                              atapi_cmnd.arglen, &dev->tag);
        if (res == LV1_DENIED_BY_POLICY) {
                dev_dbg(&dev->sbd.core,
                        "%s:%u: ATAPI command 0x%02x denied by policy\n",
                        __func__, __LINE__, opcode);
                return DID_ERROR << 16;
        }

        if (res) {
                dev_err(&dev->sbd.core,
                        "%s:%u: ATAPI command 0x%02x failed %d\n", __func__,
                        __LINE__, opcode, res);
                return DID_ERROR << 16;
        }

        return 0;
}

static inline unsigned int srb10_lba(const struct scsi_cmnd *cmd)
{
        return cmd->cmnd[2] << 24 | cmd->cmnd[3] << 16 | cmd->cmnd[4] << 8 |
               cmd->cmnd[5];
}

static inline unsigned int srb10_len(const struct scsi_cmnd *cmd)
{
        return cmd->cmnd[7] << 8 | cmd->cmnd[8];
}

static int ps3rom_read_request(struct ps3_storage_device *dev,
                               struct scsi_cmnd *cmd, u32 start_sector,
                               u32 sectors)
{
        int res;

        dev_dbg(&dev->sbd.core, "%s:%u: read %u sectors starting at %u\n",
                __func__, __LINE__, sectors, start_sector);

        res = lv1_storage_read(dev->sbd.dev_id,
                               dev->regions[dev->region_idx].id, start_sector,
                               sectors, 0, dev->bounce_lpar, &dev->tag);
        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: read failed %d\n", __func__,
                        __LINE__, res);
                return DID_ERROR << 16;
        }

        return 0;
}

static int ps3rom_write_request(struct ps3_storage_device *dev,
                                struct scsi_cmnd *cmd, u32 start_sector,
                                u32 sectors)
{
        int res;

        dev_dbg(&dev->sbd.core, "%s:%u: write %u sectors starting at %u\n",
                __func__, __LINE__, sectors, start_sector);

        scsi_sg_copy_to_buffer(cmd, dev->bounce_buf, dev->bounce_size);

        res = lv1_storage_write(dev->sbd.dev_id,
                                dev->regions[dev->region_idx].id, start_sector,
                                sectors, 0, dev->bounce_lpar, &dev->tag);
        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: write failed %d\n", __func__,
                        __LINE__, res);
                return DID_ERROR << 16;
        }

        return 0;
}

static enum scsi_qc_status ps3rom_queuecommand_lck(struct scsi_cmnd *cmd)
{
        struct ps3rom_private *priv = shost_priv(cmd->device->host);
        struct ps3_storage_device *dev = priv->dev;
        unsigned char opcode;
        int res;

        priv->curr_cmd = cmd;

        opcode = cmd->cmnd[0];
        /*
         * While we can submit READ/WRITE SCSI commands as ATAPI commands,
         * it's recommended for various reasons (performance, error handling,
         * ...) to use lv1_storage_{read,write}() instead
         */
        switch (opcode) {
        case READ_10:
                res = ps3rom_read_request(dev, cmd, srb10_lba(cmd),
                                          srb10_len(cmd));
                break;

        case WRITE_10:
                res = ps3rom_write_request(dev, cmd, srb10_lba(cmd),
                                           srb10_len(cmd));
                break;

        default:
                res = ps3rom_atapi_request(dev, cmd);
                break;
        }

        if (res) {
                scsi_build_sense(cmd, 0, ILLEGAL_REQUEST, 0, 0);
                cmd->result = res;
                priv->curr_cmd = NULL;
                scsi_done(cmd);
        }

        return 0;
}

static DEF_SCSI_QCMD(ps3rom_queuecommand)

static int decode_lv1_status(u64 status, unsigned char *sense_key,
                             unsigned char *asc, unsigned char *ascq)
{
        if (((status >> 24) & 0xff) != SAM_STAT_CHECK_CONDITION)
                return -1;

        *sense_key = (status >> 16) & 0xff;
        *asc       = (status >>  8) & 0xff;
        *ascq      =  status        & 0xff;
        return 0;
}

static irqreturn_t ps3rom_interrupt(int irq, void *data)
{
        struct ps3_storage_device *dev = data;
        struct Scsi_Host *host;
        struct ps3rom_private *priv;
        struct scsi_cmnd *cmd;
        int res;
        u64 tag, status;
        unsigned char sense_key, asc, ascq;

        res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);
        /*
         * status = -1 may mean that ATAPI transport completed OK, but
         * ATAPI command itself resulted CHECK CONDITION
         * so, upper layer should issue REQUEST_SENSE to check the sense data
         */

        if (tag != dev->tag)
                dev_err(&dev->sbd.core,
                        "%s:%u: tag mismatch, got %llx, expected %llx\n",
                        __func__, __LINE__, tag, dev->tag);

        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%llx\n",
                        __func__, __LINE__, res, status);
                return IRQ_HANDLED;
        }

        host = ps3_system_bus_get_drvdata(&dev->sbd);
        priv = shost_priv(host);
        cmd = priv->curr_cmd;

        if (!status) {
                /* OK, completed */
                if (cmd->sc_data_direction == DMA_FROM_DEVICE) {
                        int len;

                        len = scsi_sg_copy_from_buffer(cmd,
                                                       dev->bounce_buf,
                                                       dev->bounce_size);

                        scsi_set_resid(cmd, scsi_bufflen(cmd) - len);
                }
                cmd->result = DID_OK << 16;
                goto done;
        }

        if (cmd->cmnd[0] == REQUEST_SENSE) {
                /* SCSI spec says request sense should never get error */
                dev_err(&dev->sbd.core, "%s:%u: end error without autosense\n",
                        __func__, __LINE__);
                cmd->result = DID_ERROR << 16 | SAM_STAT_CHECK_CONDITION;
                goto done;
        }

        if (decode_lv1_status(status, &sense_key, &asc, &ascq)) {
                cmd->result = DID_ERROR << 16;
                goto done;
        }

        scsi_build_sense(cmd, 0, sense_key, asc, ascq);

done:
        priv->curr_cmd = NULL;
        scsi_done(cmd);
        return IRQ_HANDLED;
}

static const struct scsi_host_template ps3rom_host_template = {
        .name =                 DEVICE_NAME,
        .sdev_configure =       ps3rom_sdev_configure,
        .queuecommand =         ps3rom_queuecommand,
        .can_queue =            1,
        .this_id =              7,
        .sg_tablesize =         SG_ALL,
        .emulated =             1,              /* only sg driver uses this */
        .max_sectors =          PS3ROM_MAX_SECTORS,
        .module =               THIS_MODULE,
};


static int ps3rom_probe(struct ps3_system_bus_device *_dev)
{
        struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
        int error;
        struct Scsi_Host *host;
        struct ps3rom_private *priv;

        if (dev->blk_size != CD_FRAMESIZE) {
                dev_err(&dev->sbd.core,
                        "%s:%u: cannot handle block size %llu\n", __func__,
                        __LINE__, dev->blk_size);
                return -EINVAL;
        }

        dev->bounce_size = BOUNCE_SIZE;
        dev->bounce_buf = kmalloc(BOUNCE_SIZE, GFP_DMA);
        if (!dev->bounce_buf)
                return -ENOMEM;

        error = ps3stor_setup(dev, ps3rom_interrupt);
        if (error)
                goto fail_free_bounce;

        host = scsi_host_alloc(&ps3rom_host_template,
                               sizeof(struct ps3rom_private));
        if (!host) {
                dev_err(&dev->sbd.core, "%s:%u: scsi_host_alloc failed\n",
                        __func__, __LINE__);
                error = -ENOMEM;
                goto fail_teardown;
        }

        priv = shost_priv(host);
        ps3_system_bus_set_drvdata(&dev->sbd, host);
        priv->dev = dev;

        /* One device/LUN per SCSI bus */
        host->max_id = 1;
        host->max_lun = 1;

        error = scsi_add_host(host, &dev->sbd.core);
        if (error) {
                dev_err(&dev->sbd.core, "%s:%u: scsi_host_alloc failed %d\n",
                        __func__, __LINE__, error);
                error = -ENODEV;
                goto fail_host_put;
        }

        scsi_scan_host(host);
        return 0;

fail_host_put:
        scsi_host_put(host);
        ps3_system_bus_set_drvdata(&dev->sbd, NULL);
fail_teardown:
        ps3stor_teardown(dev);
fail_free_bounce:
        kfree(dev->bounce_buf);
        return error;
}

static void ps3rom_remove(struct ps3_system_bus_device *_dev)
{
        struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
        struct Scsi_Host *host = ps3_system_bus_get_drvdata(&dev->sbd);

        scsi_remove_host(host);
        ps3stor_teardown(dev);
        scsi_host_put(host);
        ps3_system_bus_set_drvdata(&dev->sbd, NULL);
        kfree(dev->bounce_buf);
}

static struct ps3_system_bus_driver ps3rom = {
        .match_id       = PS3_MATCH_ID_STOR_ROM,
        .core.name      = DEVICE_NAME,
        .core.owner     = THIS_MODULE,
        .probe          = ps3rom_probe,
        .remove         = ps3rom_remove
};


static int __init ps3rom_init(void)
{
        return ps3_system_bus_driver_register(&ps3rom);
}

static void __exit ps3rom_exit(void)
{
        ps3_system_bus_driver_unregister(&ps3rom);
}

module_init(ps3rom_init);
module_exit(ps3rom_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PS3 BD/DVD/CD-ROM Storage Driver");
MODULE_AUTHOR("Sony Corporation");
MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_ROM);