[mirror_ubuntu-kernels.git] / drivers / ide / ide-atapi.c

/*
 * ATAPI support.
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ide.h>
#include <scsi/scsi.h>

#ifdef DEBUG
#define debug_log(fmt, args...) \
        printk(KERN_INFO "ide: " fmt, ## args)
#else
#define debug_log(fmt, args...) do {} while (0)
#endif

/*
 * Check whether we can support a device,
 * based on the ATAPI IDENTIFY command results.
 */
int ide_check_atapi_device(ide_drive_t *drive, const char *s)
{
        u16 *id = drive->id;
        u8 gcw[2], protocol, device_type, removable, drq_type, packet_size;

        *((u16 *)&gcw) = id[ATA_ID_CONFIG];

        protocol    = (gcw[1] & 0xC0) >> 6;
        device_type =  gcw[1] & 0x1F;
        removable   = (gcw[0] & 0x80) >> 7;
        drq_type    = (gcw[0] & 0x60) >> 5;
        packet_size =  gcw[0] & 0x03;

#ifdef CONFIG_PPC
        /* kludge for Apple PowerBook internal zip */
        if (drive->media == ide_floppy && device_type == 5 &&
            !strstr((char *)&id[ATA_ID_PROD], "CD-ROM") &&
            strstr((char *)&id[ATA_ID_PROD], "ZIP"))
                device_type = 0;
#endif

        if (protocol != 2)
                printk(KERN_ERR "%s: %s: protocol (0x%02x) is not ATAPI\n",
                        s, drive->name, protocol);
        else if ((drive->media == ide_floppy && device_type != 0) ||
                 (drive->media == ide_tape && device_type != 1))
                printk(KERN_ERR "%s: %s: invalid device type (0x%02x)\n",
                        s, drive->name, device_type);
        else if (removable == 0)
                printk(KERN_ERR "%s: %s: the removable flag is not set\n",
                        s, drive->name);
        else if (drive->media == ide_floppy && drq_type == 3)
                printk(KERN_ERR "%s: %s: sorry, DRQ type (0x%02x) not "
                        "supported\n", s, drive->name, drq_type);
        else if (packet_size != 0)
                printk(KERN_ERR "%s: %s: packet size (0x%02x) is not 12 "
                        "bytes\n", s, drive->name, packet_size);
        else
                return 1;
        return 0;
}
EXPORT_SYMBOL_GPL(ide_check_atapi_device);

/* PIO data transfer routine using the scatter gather table. */
int ide_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                    unsigned int bcount, int write)
{
        ide_hwif_t *hwif = drive->hwif;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        xfer_func_t *xf = write ? tp_ops->output_data : tp_ops->input_data;
        struct scatterlist *sg = pc->sg;
        char *buf;
        int count, done = 0;

        while (bcount) {
                count = min(sg->length - pc->b_count, bcount);

                if (PageHighMem(sg_page(sg))) {
                        unsigned long flags;

                        local_irq_save(flags);
                        buf = kmap_atomic(sg_page(sg), KM_IRQ0) + sg->offset;
                        xf(drive, NULL, buf + pc->b_count, count);
                        kunmap_atomic(buf - sg->offset, KM_IRQ0);
                        local_irq_restore(flags);
                } else {
                        buf = sg_virt(sg);
                        xf(drive, NULL, buf + pc->b_count, count);
                }

                bcount -= count;
                pc->b_count += count;
                done += count;

                if (pc->b_count == sg->length) {
                        if (!--pc->sg_cnt)
                                break;
                        pc->sg = sg = sg_next(sg);
                        pc->b_count = 0;
                }
        }

        if (bcount) {
                printk(KERN_ERR "%s: %d leftover bytes, %s\n", drive->name,
                        bcount, write ? "padding with zeros"
                                      : "discarding data");
                ide_pad_transfer(drive, write, bcount);
        }

        return done;
}
EXPORT_SYMBOL_GPL(ide_io_buffers);

void ide_init_pc(struct ide_atapi_pc *pc)
{
        memset(pc, 0, sizeof(*pc));
        pc->buf = pc->pc_buf;
        pc->buf_size = IDE_PC_BUFFER_SIZE;
}
EXPORT_SYMBOL_GPL(ide_init_pc);

/*
 * Generate a new packet command request in front of the request queue, before
 * the current request, so that it will be processed immediately, on the next
 * pass through the driver.
 */
static void ide_queue_pc_head(ide_drive_t *drive, struct gendisk *disk,
                              struct ide_atapi_pc *pc, struct request *rq)
{
        blk_rq_init(NULL, rq);
        rq->cmd_type = REQ_TYPE_SPECIAL;
        rq->cmd_flags |= REQ_PREEMPT;
        rq->buffer = (char *)pc;
        rq->rq_disk = disk;
        memcpy(rq->cmd, pc->c, 12);
        if (drive->media == ide_tape)
                rq->cmd[13] = REQ_IDETAPE_PC1;
        ide_do_drive_cmd(drive, rq);
}

/*
 * Add a special packet command request to the tail of the request queue,
 * and wait for it to be serviced.
 */
int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
                      struct ide_atapi_pc *pc)
{
        struct request *rq;
        int error;

        rq = blk_get_request(drive->queue, READ, __GFP_WAIT);
        rq->cmd_type = REQ_TYPE_SPECIAL;
        rq->buffer = (char *)pc;
        memcpy(rq->cmd, pc->c, 12);
        if (drive->media == ide_tape)
                rq->cmd[13] = REQ_IDETAPE_PC1;
        error = blk_execute_rq(drive->queue, disk, rq, 0);
        blk_put_request(rq);

        return error;
}
EXPORT_SYMBOL_GPL(ide_queue_pc_tail);

int ide_do_test_unit_ready(ide_drive_t *drive, struct gendisk *disk)
{
        struct ide_atapi_pc pc;

        ide_init_pc(&pc);
        pc.c[0] = TEST_UNIT_READY;

        return ide_queue_pc_tail(drive, disk, &pc);
}
EXPORT_SYMBOL_GPL(ide_do_test_unit_ready);

int ide_do_start_stop(ide_drive_t *drive, struct gendisk *disk, int start)
{
        struct ide_atapi_pc pc;

        ide_init_pc(&pc);
        pc.c[0] = START_STOP;
        pc.c[4] = start;

        if (drive->media == ide_tape)
                pc.flags |= PC_FLAG_WAIT_FOR_DSC;

        return ide_queue_pc_tail(drive, disk, &pc);
}
EXPORT_SYMBOL_GPL(ide_do_start_stop);

int ide_set_media_lock(ide_drive_t *drive, struct gendisk *disk, int on)
{
        struct ide_atapi_pc pc;

        if (drive->atapi_flags & IDE_AFLAG_NO_DOORLOCK)
                return 0;

        ide_init_pc(&pc);
        pc.c[0] = ALLOW_MEDIUM_REMOVAL;
        pc.c[4] = on;

        return ide_queue_pc_tail(drive, disk, &pc);
}
EXPORT_SYMBOL_GPL(ide_set_media_lock);

void ide_create_request_sense_cmd(ide_drive_t *drive, struct ide_atapi_pc *pc)
{
        ide_init_pc(pc);
        pc->c[0] = REQUEST_SENSE;
        if (drive->media == ide_floppy) {
                pc->c[4] = 255;
                pc->req_xfer = 18;
        } else {
                pc->c[4] = 20;
                pc->req_xfer = 20;
        }
}
EXPORT_SYMBOL_GPL(ide_create_request_sense_cmd);

/*
 * Called when an error was detected during the last packet command.
 * We queue a request sense packet command in the head of the request list.
 */
void ide_retry_pc(ide_drive_t *drive, struct gendisk *disk)
{
        struct request *rq = &drive->request_sense_rq;
        struct ide_atapi_pc *pc = &drive->request_sense_pc;

        (void)ide_read_error(drive);
        ide_create_request_sense_cmd(drive, pc);
        if (drive->media == ide_tape)
                set_bit(IDE_AFLAG_IGNORE_DSC, &drive->atapi_flags);
        ide_queue_pc_head(drive, disk, pc, rq);
}
EXPORT_SYMBOL_GPL(ide_retry_pc);

int ide_scsi_expiry(ide_drive_t *drive)
{
        struct ide_atapi_pc *pc = drive->pc;

        debug_log("%s called for %lu at %lu\n", __func__,
                  pc->scsi_cmd->serial_number, jiffies);

        pc->flags |= PC_FLAG_TIMEDOUT;

        return 0; /* we do not want the IDE subsystem to retry */
}
EXPORT_SYMBOL_GPL(ide_scsi_expiry);

/* TODO: unify the code thus making some arguments go away */
ide_startstop_t ide_pc_intr(ide_drive_t *drive, ide_handler_t *handler,
        void (*update_buffers)(ide_drive_t *, struct ide_atapi_pc *),
        int (*io_buffers)(ide_drive_t *, struct ide_atapi_pc *, unsigned, int))
{
        struct ide_atapi_pc *pc = drive->pc;
        ide_hwif_t *hwif = drive->hwif;
        struct request *rq = hwif->hwgroup->rq;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        xfer_func_t *xferfunc;
        ide_expiry_t *expiry;
        unsigned int timeout, temp;
        u16 bcount;
        u8 stat, ireason, scsi = drive->scsi, dsc = 0;

        debug_log("Enter %s - interrupt handler\n", __func__);

        if (scsi) {
                timeout = ide_scsi_get_timeout(pc);
                expiry = ide_scsi_expiry;
        } else {
                timeout = (drive->media == ide_floppy) ? WAIT_FLOPPY_CMD
                                                       : WAIT_TAPE_CMD;
                expiry = NULL;
        }

        if (pc->flags & PC_FLAG_TIMEDOUT) {
                drive->pc_callback(drive, 0);
                return ide_stopped;
        }

        /* Clear the interrupt */
        stat = tp_ops->read_status(hwif);

        if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
                if (hwif->dma_ops->dma_end(drive) ||
                    (drive->media == ide_tape && !scsi && (stat & ATA_ERR))) {
                        if (drive->media == ide_floppy && !scsi)
                                printk(KERN_ERR "%s: DMA %s error\n",
                                        drive->name, rq_data_dir(pc->rq)
                                                     ? "write" : "read");
                        pc->flags |= PC_FLAG_DMA_ERROR;
                } else {
                        pc->xferred = pc->req_xfer;
                        if (update_buffers)
                                update_buffers(drive, pc);
                }
                debug_log("%s: DMA finished\n", drive->name);
        }

        /* No more interrupts */
        if ((stat & ATA_DRQ) == 0) {
                debug_log("Packet command completed, %d bytes transferred\n",
                          pc->xferred);

                pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;

                local_irq_enable_in_hardirq();

                if (drive->media == ide_tape && !scsi &&
                    (stat & ATA_ERR) && rq->cmd[0] == REQUEST_SENSE)
                        stat &= ~ATA_ERR;

                if ((stat & ATA_ERR) || (pc->flags & PC_FLAG_DMA_ERROR)) {
                        /* Error detected */
                        debug_log("%s: I/O error\n", drive->name);

                        if (drive->media != ide_tape || scsi) {
                                pc->rq->errors++;
                                if (scsi)
                                        goto cmd_finished;
                        }

                        if (rq->cmd[0] == REQUEST_SENSE) {
                                printk(KERN_ERR "%s: I/O error in request sense"
                                                " command\n", drive->name);
                                return ide_do_reset(drive);
                        }

                        debug_log("[cmd %x]: check condition\n", rq->cmd[0]);

                        /* Retry operation */
                        ide_retry_pc(drive, rq->rq_disk);

                        /* queued, but not started */
                        return ide_stopped;
                }
cmd_finished:
                pc->error = 0;

                if ((pc->flags & PC_FLAG_WAIT_FOR_DSC) && (stat & ATA_DSC) == 0)
                        dsc = 1;

                /* Command finished - Call the callback function */
                drive->pc_callback(drive, dsc);

                return ide_stopped;
        }

        if (pc->flags & PC_FLAG_DMA_IN_PROGRESS) {
                pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
                printk(KERN_ERR "%s: The device wants to issue more interrupts "
                                "in DMA mode\n", drive->name);
                ide_dma_off(drive);
                return ide_do_reset(drive);
        }

        /* Get the number of bytes to transfer on this interrupt. */
        ide_read_bcount_and_ireason(drive, &bcount, &ireason);

        if (ireason & ATAPI_COD) {
                printk(KERN_ERR "%s: CoD != 0 in %s\n", drive->name, __func__);
                return ide_do_reset(drive);
        }

        if (((ireason & ATAPI_IO) == ATAPI_IO) ==
                !!(pc->flags & PC_FLAG_WRITING)) {
                /* Hopefully, we will never get here */
                printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
                                "to %s!\n", drive->name,
                                (ireason & ATAPI_IO) ? "Write" : "Read",
                                (ireason & ATAPI_IO) ? "Read" : "Write");
                return ide_do_reset(drive);
        }

        if (!(pc->flags & PC_FLAG_WRITING)) {
                /* Reading - Check that we have enough space */
                temp = pc->xferred + bcount;
                if (temp > pc->req_xfer) {
                        if (temp > pc->buf_size) {
                                printk(KERN_ERR "%s: The device wants to send "
                                                "us more data than expected - "
                                                "discarding data\n",
                                                drive->name);
                                if (scsi)
                                        temp = pc->buf_size - pc->xferred;
                                else
                                        temp = 0;
                                if (temp) {
                                        if (pc->sg)
                                                io_buffers(drive, pc, temp, 0);
                                        else
                                                tp_ops->input_data(drive, NULL,
                                                        pc->cur_pos, temp);
                                        printk(KERN_ERR "%s: transferred %d of "
                                                        "%d bytes\n",
                                                        drive->name,
                                                        temp, bcount);
                                }
                                pc->xferred += temp;
                                pc->cur_pos += temp;
                                ide_pad_transfer(drive, 0, bcount - temp);
                                goto next_irq;
                        }
                        debug_log("The device wants to send us more data than "
                                  "expected - allowing transfer\n");
                }
                xferfunc = tp_ops->input_data;
        } else
                xferfunc = tp_ops->output_data;

        if ((drive->media == ide_floppy && !scsi && !pc->buf) ||
            (drive->media == ide_tape && !scsi && pc->bh) ||
            (scsi && pc->sg)) {
                int done = io_buffers(drive, pc, bcount,
                                  !!(pc->flags & PC_FLAG_WRITING));

                /* FIXME: don't do partial completions */
                if (drive->media == ide_floppy && !scsi)
                        ide_end_request(drive, 1, done >> 9);
        } else
                xferfunc(drive, NULL, pc->cur_pos, bcount);

        /* Update the current position */
        pc->xferred += bcount;
        pc->cur_pos += bcount;

        debug_log("[cmd %x] transferred %d bytes on that intr.\n",
                  rq->cmd[0], bcount);
next_irq:
        /* And set the interrupt handler again */
        ide_set_handler(drive, handler, timeout, expiry);
        return ide_started;
}
EXPORT_SYMBOL_GPL(ide_pc_intr);

static u8 ide_read_ireason(ide_drive_t *drive)
{
        ide_task_t task;

        memset(&task, 0, sizeof(task));
        task.tf_flags = IDE_TFLAG_IN_NSECT;

        drive->hwif->tp_ops->tf_read(drive, &task);

        return task.tf.nsect & 3;
}

static u8 ide_wait_ireason(ide_drive_t *drive, u8 ireason)
{
        int retries = 100;

        while (retries-- && ((ireason & ATAPI_COD) == 0 ||
                (ireason & ATAPI_IO))) {
                printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
                                "a packet command, retrying\n", drive->name);
                udelay(100);
                ireason = ide_read_ireason(drive);
                if (retries == 0) {
                        printk(KERN_ERR "%s: (IO,CoD != (0,1) while issuing "
                                        "a packet command, ignoring\n",
                                        drive->name);
                        ireason |= ATAPI_COD;
                        ireason &= ~ATAPI_IO;
                }
        }

        return ireason;
}

ide_startstop_t ide_transfer_pc(ide_drive_t *drive,
                                ide_handler_t *handler, unsigned int timeout,
                                ide_expiry_t *expiry)
{
        struct ide_atapi_pc *pc = drive->pc;
        ide_hwif_t *hwif = drive->hwif;
        struct request *rq = hwif->hwgroup->rq;
        ide_startstop_t startstop;
        u8 ireason;

        if (ide_wait_stat(&startstop, drive, ATA_DRQ, ATA_BUSY, WAIT_READY)) {
                printk(KERN_ERR "%s: Strange, packet command initiated yet "
                                "DRQ isn't asserted\n", drive->name);
                return startstop;
        }

        ireason = ide_read_ireason(drive);
        if (drive->media == ide_tape && !drive->scsi)
                ireason = ide_wait_ireason(drive, ireason);

        if ((ireason & ATAPI_COD) == 0 || (ireason & ATAPI_IO)) {
                printk(KERN_ERR "%s: (IO,CoD) != (0,1) while issuing "
                                "a packet command\n", drive->name);
                return ide_do_reset(drive);
        }

        /* Set the interrupt routine */
        ide_set_handler(drive, handler, timeout, expiry);

        /* Begin DMA, if necessary */
        if (pc->flags & PC_FLAG_DMA_OK) {
                pc->flags |= PC_FLAG_DMA_IN_PROGRESS;
                hwif->dma_ops->dma_start(drive);
        }

        /* Send the actual packet */
        if ((drive->atapi_flags & IDE_AFLAG_ZIP_DRIVE) == 0)
                hwif->tp_ops->output_data(drive, NULL, rq->cmd, 12);

        return ide_started;
}
EXPORT_SYMBOL_GPL(ide_transfer_pc);

ide_startstop_t ide_issue_pc(ide_drive_t *drive,
                             ide_handler_t *handler, unsigned int timeout,
                             ide_expiry_t *expiry)
{
        struct ide_atapi_pc *pc = drive->pc;
        ide_hwif_t *hwif = drive->hwif;
        u16 bcount;
        u8 dma = 0;

        /* We haven't transferred any data yet */
        pc->xferred = 0;
        pc->cur_pos = pc->buf;

        /* Request to transfer the entire buffer at once */
        if (drive->media == ide_tape && !drive->scsi)
                bcount = pc->req_xfer;
        else
                bcount = min(pc->req_xfer, 63 * 1024);

        if (pc->flags & PC_FLAG_DMA_ERROR) {
                pc->flags &= ~PC_FLAG_DMA_ERROR;
                ide_dma_off(drive);
        }

        if ((pc->flags & PC_FLAG_DMA_OK) && drive->using_dma) {
                if (drive->scsi)
                        hwif->sg_mapped = 1;
                dma = !hwif->dma_ops->dma_setup(drive);
                if (drive->scsi)
                        hwif->sg_mapped = 0;
        }

        if (!dma)
                pc->flags &= ~PC_FLAG_DMA_OK;

        ide_pktcmd_tf_load(drive, drive->scsi ? 0 : IDE_TFLAG_OUT_DEVICE,
                           bcount, dma);

        /* Issue the packet command */
        if (drive->atapi_flags & IDE_AFLAG_DRQ_INTERRUPT) {
                ide_execute_command(drive, ATA_CMD_PACKET, handler,
                                    timeout, NULL);
                return ide_started;
        } else {
                ide_execute_pkt_cmd(drive);
                return (*handler)(drive);
        }
}
EXPORT_SYMBOL_GPL(ide_issue_pc);