root/drivers/block/ps3disk.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * PS3 Disk Storage Driver
 *
 * Copyright (C) 2007 Sony Computer Entertainment Inc.
 * Copyright 2007 Sony Corp.
 */

#include <linux/ata.h>
#include <linux/blk-mq.h>
#include <linux/slab.h>
#include <linux/module.h>

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


#define DEVICE_NAME             "ps3disk"

#define BOUNCE_SIZE             (64*1024)

#define PS3DISK_MAX_DISKS       16
#define PS3DISK_MINORS          16


#define PS3DISK_NAME            "ps3d%c"


struct ps3disk_private {
        spinlock_t lock;                /* Request queue spinlock */
        struct blk_mq_tag_set tag_set;
        struct gendisk *gendisk;
        unsigned int blocking_factor;
        struct request *req;
        u64 raw_capacity;
        unsigned char model[ATA_ID_PROD_LEN+1];
};


#define LV1_STORAGE_SEND_ATA_COMMAND    (2)
#define LV1_STORAGE_ATA_HDDOUT          (0x23)

struct lv1_ata_cmnd_block {
        u16     features;
        u16     sector_count;
        u16     LBA_low;
        u16     LBA_mid;
        u16     LBA_high;
        u8      device;
        u8      command;
        u32     is_ext;
        u32     proto;
        u32     in_out;
        u32     size;
        u64     buffer;
        u32     arglen;
};

enum lv1_ata_proto {
        NON_DATA_PROTO     = 0,
        PIO_DATA_IN_PROTO  = 1,
        PIO_DATA_OUT_PROTO = 2,
        DMA_PROTO = 3
};

enum lv1_ata_in_out {
        DIR_WRITE = 0,                  /* memory -> device */
        DIR_READ = 1                    /* device -> memory */
};

static int ps3disk_major;


static const struct block_device_operations ps3disk_fops = {
        .owner          = THIS_MODULE,
};


static void ps3disk_scatter_gather(struct ps3_storage_device *dev,
                                   struct request *req, int gather)
{
        unsigned int offset = 0;
        struct req_iterator iter;
        struct bio_vec bvec;

        rq_for_each_segment(bvec, req, iter) {
                dev_dbg(&dev->sbd.core, "%s:%u: %u sectors from %llu\n",
                        __func__, __LINE__, bio_sectors(iter.bio),
                        iter.bio->bi_iter.bi_sector);
                if (gather)
                        memcpy_from_bvec(dev->bounce_buf + offset, &bvec);
                else
                        memcpy_to_bvec(&bvec, dev->bounce_buf + offset);
                offset += bvec.bv_len;
        }
}

static blk_status_t ps3disk_submit_request_sg(struct ps3_storage_device *dev,
                                              struct request *req)
{
        struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
        int write = rq_data_dir(req), res;
        const char *op = write ? "write" : "read";
        u64 start_sector, sectors;
        unsigned int region_id = dev->regions[dev->region_idx].id;

#ifdef DEBUG
        unsigned int n = 0;
        struct bio_vec bv;
        struct req_iterator iter;

        rq_for_each_segment(bv, req, iter)
                n++;
        dev_dbg(&dev->sbd.core,
                "%s:%u: %s req has %u bvecs for %u sectors\n",
                __func__, __LINE__, op, n, blk_rq_sectors(req));
#endif

        start_sector = blk_rq_pos(req) * priv->blocking_factor;
        sectors = blk_rq_sectors(req) * priv->blocking_factor;
        dev_dbg(&dev->sbd.core, "%s:%u: %s %llu sectors starting at %llu\n",
                __func__, __LINE__, op, sectors, start_sector);

        if (write) {
                ps3disk_scatter_gather(dev, req, 1);

                res = lv1_storage_write(dev->sbd.dev_id, region_id,
                                        start_sector, sectors, 0,
                                        dev->bounce_lpar, &dev->tag);
        } else {
                res = lv1_storage_read(dev->sbd.dev_id, region_id,
                                       start_sector, sectors, 0,
                                       dev->bounce_lpar, &dev->tag);
        }
        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: %s failed %d\n", __func__,
                        __LINE__, op, res);
                return BLK_STS_IOERR;
        }

        priv->req = req;
        return BLK_STS_OK;
}

static blk_status_t ps3disk_submit_flush_request(struct ps3_storage_device *dev,
                                                 struct request *req)
{
        struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
        u64 res;

        dev_dbg(&dev->sbd.core, "%s:%u: flush request\n", __func__, __LINE__);

        res = lv1_storage_send_device_command(dev->sbd.dev_id,
                                              LV1_STORAGE_ATA_HDDOUT, 0, 0, 0,
                                              0, &dev->tag);
        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: sync cache failed 0x%llx\n",
                        __func__, __LINE__, res);
                return BLK_STS_IOERR;
        }

        priv->req = req;
        return BLK_STS_OK;
}

static blk_status_t ps3disk_do_request(struct ps3_storage_device *dev,
                                       struct request *req)
{
        dev_dbg(&dev->sbd.core, "%s:%u\n", __func__, __LINE__);

        switch (req_op(req)) {
        case REQ_OP_FLUSH:
                return ps3disk_submit_flush_request(dev, req);
        case REQ_OP_READ:
        case REQ_OP_WRITE:
                return ps3disk_submit_request_sg(dev, req);
        default:
                blk_dump_rq_flags(req, DEVICE_NAME " bad request");
                return BLK_STS_IOERR;
        }
}

static blk_status_t ps3disk_queue_rq(struct blk_mq_hw_ctx *hctx,
                                     const struct blk_mq_queue_data *bd)
{
        struct request_queue *q = hctx->queue;
        struct ps3_storage_device *dev = q->queuedata;
        struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
        blk_status_t ret;

        blk_mq_start_request(bd->rq);

        spin_lock_irq(&priv->lock);
        ret = ps3disk_do_request(dev, bd->rq);
        spin_unlock_irq(&priv->lock);

        return ret;
}

static irqreturn_t ps3disk_interrupt(int irq, void *data)
{
        struct ps3_storage_device *dev = data;
        struct ps3disk_private *priv;
        struct request *req;
        int res, read;
        blk_status_t error;
        u64 tag, status;
        const char *op;

        res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);

        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;
        }

        priv = ps3_system_bus_get_drvdata(&dev->sbd);
        req = priv->req;
        if (!req) {
                dev_dbg(&dev->sbd.core,
                        "%s:%u non-block layer request completed\n", __func__,
                        __LINE__);
                dev->lv1_status = status;
                complete(&dev->done);
                return IRQ_HANDLED;
        }

        if (req_op(req) == REQ_OP_FLUSH) {
                read = 0;
                op = "flush";
        } else {
                read = !rq_data_dir(req);
                op = read ? "read" : "write";
        }
        if (status) {
                dev_dbg(&dev->sbd.core, "%s:%u: %s failed 0x%llx\n", __func__,
                        __LINE__, op, status);
                error = BLK_STS_IOERR;
        } else {
                dev_dbg(&dev->sbd.core, "%s:%u: %s completed\n", __func__,
                        __LINE__, op);
                error = 0;
                if (read)
                        ps3disk_scatter_gather(dev, req, 0);
        }

        spin_lock(&priv->lock);
        priv->req = NULL;
        blk_mq_end_request(req, error);
        spin_unlock(&priv->lock);

        blk_mq_run_hw_queues(priv->gendisk->queue, true);
        return IRQ_HANDLED;
}

static int ps3disk_sync_cache(struct ps3_storage_device *dev)
{
        u64 res;

        dev_dbg(&dev->sbd.core, "%s:%u: sync cache\n", __func__, __LINE__);

        res = ps3stor_send_command(dev, LV1_STORAGE_ATA_HDDOUT, 0, 0, 0, 0);
        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: sync cache failed 0x%llx\n",
                        __func__, __LINE__, res);
                return -EIO;
        }
        return 0;
}


/* ATA helpers copied from drivers/ata/libata-core.c */

static void swap_buf_le16(u16 *buf, unsigned int buf_words)
{
#ifdef __BIG_ENDIAN
        unsigned int i;

        for (i = 0; i < buf_words; i++)
                buf[i] = le16_to_cpu(buf[i]);
#endif /* __BIG_ENDIAN */
}

static u64 ata_id_n_sectors(const u16 *id)
{
        if (ata_id_has_lba(id)) {
                if (ata_id_has_lba48(id))
                        return ata_id_u64(id, 100);
                else
                        return ata_id_u32(id, 60);
        } else {
                if (ata_id_current_chs_valid(id))
                        return ata_id_u32(id, 57);
                else
                        return id[1] * id[3] * id[6];
        }
}

static void ata_id_string(const u16 *id, unsigned char *s, unsigned int ofs,
                          unsigned int len)
{
        unsigned int c;

        while (len > 0) {
                c = id[ofs] >> 8;
                *s = c;
                s++;

                c = id[ofs] & 0xff;
                *s = c;
                s++;

                ofs++;
                len -= 2;
        }
}

static void ata_id_c_string(const u16 *id, unsigned char *s, unsigned int ofs,
                            unsigned int len)
{
        unsigned char *p;

        WARN_ON(!(len & 1));

        ata_id_string(id, s, ofs, len - 1);

        p = s + strnlen(s, len - 1);
        while (p > s && p[-1] == ' ')
                p--;
        *p = '\0';
}

static int ps3disk_identify(struct ps3_storage_device *dev)
{
        struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
        struct lv1_ata_cmnd_block ata_cmnd;
        u16 *id = dev->bounce_buf;
        u64 res;

        dev_dbg(&dev->sbd.core, "%s:%u: identify disk\n", __func__, __LINE__);

        memset(&ata_cmnd, 0, sizeof(struct lv1_ata_cmnd_block));
        ata_cmnd.command = ATA_CMD_ID_ATA;
        ata_cmnd.sector_count = 1;
        ata_cmnd.size = ata_cmnd.arglen = ATA_ID_WORDS * 2;
        ata_cmnd.buffer = dev->bounce_lpar;
        ata_cmnd.proto = PIO_DATA_IN_PROTO;
        ata_cmnd.in_out = DIR_READ;

        res = ps3stor_send_command(dev, LV1_STORAGE_SEND_ATA_COMMAND,
                                   ps3_mm_phys_to_lpar(__pa(&ata_cmnd)),
                                   sizeof(ata_cmnd), ata_cmnd.buffer,
                                   ata_cmnd.arglen);
        if (res) {
                dev_err(&dev->sbd.core, "%s:%u: identify disk failed 0x%llx\n",
                        __func__, __LINE__, res);
                return -EIO;
        }

        swap_buf_le16(id, ATA_ID_WORDS);

        /* All we're interested in are raw capacity and model name */
        priv->raw_capacity = ata_id_n_sectors(id);
        ata_id_c_string(id, priv->model, ATA_ID_PROD, sizeof(priv->model));
        return 0;
}

static unsigned long ps3disk_mask;

static DEFINE_MUTEX(ps3disk_mask_mutex);

static const struct blk_mq_ops ps3disk_mq_ops = {
        .queue_rq       = ps3disk_queue_rq,
};

static int ps3disk_probe(struct ps3_system_bus_device *_dev)
{
        struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
        struct ps3disk_private *priv;
        int error;
        unsigned int devidx;
        struct queue_limits lim = {
                .logical_block_size     = dev->blk_size,
                .max_hw_sectors         = BOUNCE_SIZE >> 9,
                .max_segments           = -1,
                .max_segment_size       = BOUNCE_SIZE,
                .dma_alignment          = dev->blk_size - 1,
                .features               = BLK_FEAT_WRITE_CACHE |
                                          BLK_FEAT_ROTATIONAL,
        };
        struct gendisk *gendisk;

        if (dev->blk_size < 512) {
                dev_err(&dev->sbd.core,
                        "%s:%u: cannot handle block size %llu\n", __func__,
                        __LINE__, dev->blk_size);
                return -EINVAL;
        }

        BUILD_BUG_ON(PS3DISK_MAX_DISKS > BITS_PER_LONG);
        mutex_lock(&ps3disk_mask_mutex);
        devidx = find_first_zero_bit(&ps3disk_mask, PS3DISK_MAX_DISKS);
        if (devidx >= PS3DISK_MAX_DISKS) {
                dev_err(&dev->sbd.core, "%s:%u: Too many disks\n", __func__,
                        __LINE__);
                mutex_unlock(&ps3disk_mask_mutex);
                return -ENOSPC;
        }
        __set_bit(devidx, &ps3disk_mask);
        mutex_unlock(&ps3disk_mask_mutex);

        priv = kzalloc_obj(*priv);
        if (!priv) {
                error = -ENOMEM;
                goto fail;
        }

        ps3_system_bus_set_drvdata(_dev, priv);
        spin_lock_init(&priv->lock);

        dev->bounce_size = BOUNCE_SIZE;
        dev->bounce_buf = kmalloc(BOUNCE_SIZE, GFP_DMA);
        if (!dev->bounce_buf) {
                error = -ENOMEM;
                goto fail_free_priv;
        }

        error = ps3stor_setup(dev, ps3disk_interrupt);
        if (error)
                goto fail_free_bounce;

        ps3disk_identify(dev);

        error = blk_mq_alloc_sq_tag_set(&priv->tag_set, &ps3disk_mq_ops, 1, 0);
        if (error)
                goto fail_teardown;

        gendisk = blk_mq_alloc_disk(&priv->tag_set, &lim, dev);
        if (IS_ERR(gendisk)) {
                dev_err(&dev->sbd.core, "%s:%u: blk_mq_alloc_disk failed\n",
                        __func__, __LINE__);
                error = PTR_ERR(gendisk);
                goto fail_free_tag_set;
        }

        priv->gendisk = gendisk;
        gendisk->major = ps3disk_major;
        gendisk->first_minor = devidx * PS3DISK_MINORS;
        gendisk->minors = PS3DISK_MINORS;
        gendisk->fops = &ps3disk_fops;
        gendisk->private_data = dev;
        snprintf(gendisk->disk_name, sizeof(gendisk->disk_name), PS3DISK_NAME,
                 devidx+'a');
        priv->blocking_factor = dev->blk_size >> 9;
        set_capacity(gendisk,
                     dev->regions[dev->region_idx].size*priv->blocking_factor);

        dev_info(&dev->sbd.core,
                 "%s is a %s (%llu MiB total, %llu MiB for OtherOS)\n",
                 gendisk->disk_name, priv->model, priv->raw_capacity >> 11,
                 get_capacity(gendisk) >> 11);

        error = device_add_disk(&dev->sbd.core, gendisk, NULL);
        if (error)
                goto fail_cleanup_disk;

        return 0;
fail_cleanup_disk:
        put_disk(gendisk);
fail_free_tag_set:
        blk_mq_free_tag_set(&priv->tag_set);
fail_teardown:
        ps3stor_teardown(dev);
fail_free_bounce:
        kfree(dev->bounce_buf);
fail_free_priv:
        kfree(priv);
        ps3_system_bus_set_drvdata(_dev, NULL);
fail:
        mutex_lock(&ps3disk_mask_mutex);
        __clear_bit(devidx, &ps3disk_mask);
        mutex_unlock(&ps3disk_mask_mutex);
        return error;
}

static void ps3disk_remove(struct ps3_system_bus_device *_dev)
{
        struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
        struct ps3disk_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);

        mutex_lock(&ps3disk_mask_mutex);
        __clear_bit(MINOR(disk_devt(priv->gendisk)) / PS3DISK_MINORS,
                    &ps3disk_mask);
        mutex_unlock(&ps3disk_mask_mutex);
        del_gendisk(priv->gendisk);
        put_disk(priv->gendisk);
        blk_mq_free_tag_set(&priv->tag_set);
        dev_notice(&dev->sbd.core, "Synchronizing disk cache\n");
        ps3disk_sync_cache(dev);
        ps3stor_teardown(dev);
        kfree(dev->bounce_buf);
        kfree(priv);
        ps3_system_bus_set_drvdata(_dev, NULL);
}

static struct ps3_system_bus_driver ps3disk = {
        .match_id       = PS3_MATCH_ID_STOR_DISK,
        .core.name      = DEVICE_NAME,
        .core.owner     = THIS_MODULE,
        .probe          = ps3disk_probe,
        .remove         = ps3disk_remove,
        .shutdown       = ps3disk_remove,
};


static int __init ps3disk_init(void)
{
        int error;

        if (!firmware_has_feature(FW_FEATURE_PS3_LV1))
                return -ENODEV;

        error = register_blkdev(0, DEVICE_NAME);
        if (error <= 0) {
                printk(KERN_ERR "%s:%u: register_blkdev failed %d\n", __func__,
                       __LINE__, error);
                return error;
        }
        ps3disk_major = error;

        pr_info("%s:%u: registered block device major %d\n", __func__,
                __LINE__, ps3disk_major);

        error = ps3_system_bus_driver_register(&ps3disk);
        if (error)
                unregister_blkdev(ps3disk_major, DEVICE_NAME);

        return error;
}

static void __exit ps3disk_exit(void)
{
        ps3_system_bus_driver_unregister(&ps3disk);
        unregister_blkdev(ps3disk_major, DEVICE_NAME);
}

module_init(ps3disk_init);
module_exit(ps3disk_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PS3 Disk Storage Driver");
MODULE_AUTHOR("Sony Corporation");
MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_DISK);