source: mainline/uspace/srv/bd/ata_bd/ata_bd.c@ e5792d1

/*
 * Copyright (c) 2009 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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 name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup bd
 * @{
 */

/**
 * @file
 * @brief ATA disk driver
 *
 * This driver currently works only with CHS addressing and uses PIO.
 * Currently based on the (now obsolete) ATA-1, ATA-2 standards.
 *
 * The driver services a single controller which can have up to two disks
 * attached.
 */

#include <stdio.h>
#include <libarch/ddi.h>
#include <ddi.h>
#include <ipc/ipc.h>
#include <ipc/bd.h>
#include <async.h>
#include <as.h>
#include <fibril_sync.h>
#include <string.h>
#include <devmap.h>
#include <sys/types.h>
#include <errno.h>
#include <bool.h>
#include <task.h>

#include "ata_bd.h"

#define NAME "ata_bd"

/** Physical block size. Should be always 512. */
static const size_t block_size = 512;

/** Size of the communication area. */
static size_t comm_size;

/** I/O base address of the command registers. */
static uintptr_t cmd_physical = 0x1f0;
/** I/O base address of the control registers. */
static uintptr_t ctl_physical = 0x170;

static ata_cmd_t *cmd;
static ata_ctl_t *ctl;

/** Per-disk state. */
static disk_t disk[MAX_DISKS];

static int ata_bd_init(void);
static void ata_bd_connection(ipc_callid_t iid, ipc_call_t *icall);
static int ata_bd_rdwr(int disk_id, ipcarg_t method, off_t offset, size_t size,
    void *buf);
static int ata_bd_read_block(int disk_id, uint64_t blk_idx, size_t blk_cnt,
    void *buf);
static int ata_bd_write_block(int disk_id, uint64_t blk_idx, size_t blk_cnt,
    const void *buf);
static int disk_init(disk_t *d, int disk_id);
static int drive_identify(int drive_id, void *buf);
static void disk_print_summary(disk_t *d);
static int wait_status(unsigned set, unsigned n_reset, uint8_t *pstatus,
    unsigned timeout);

int main(int argc, char **argv)
{
        char name[16];
        int i, rc;
        int n_disks;

        printf(NAME ": ATA disk driver\n");

        printf("I/O address 0x%x\n", cmd_physical);

        if (ata_bd_init() != EOK)
                return -1;

        for (i = 0; i < MAX_DISKS; i++) {
                printf("Identify drive %d... ", i);
                fflush(stdout);

                rc = disk_init(&disk[i], i);

                if (rc == EOK) {
                        disk_print_summary(&disk[i]);
                } else {
                        printf("Not found.\n");
                }
        }

        n_disks = 0;

        for (i = 0; i < MAX_DISKS; i++) {
                /* Skip unattached drives. */
                if (disk[i].present == false)
                        continue;

                snprintf(name, 16, "disk%d", i);
                rc = devmap_device_register(name, &disk[i].dev_handle);
                if (rc != EOK) {
                        devmap_hangup_phone(DEVMAP_DRIVER);
                        printf(NAME ": Unable to register device %s.\n",
                                name);
                        return rc;
                }
                ++n_disks;
        }

        if (n_disks == 0) {
                printf("No disks detected.\n");
                return -1;
        }

        printf(NAME ": Accepting connections\n");
        task_retval(0);
        async_manager();

        /* Not reached */
        return 0;
}

/** Print one-line device summary. */
static void disk_print_summary(disk_t *d)
{
        uint64_t mbytes;

        printf("%s: ", d->model);

        if (d->amode == am_chs) {
                printf("CHS %u cylinders, %u heads, %u sectors",
                    disk->geom.cylinders, disk->geom.heads, disk->geom.sectors);
        } else {
                printf("LBA-28");
        }

        printf(" %llu blocks", d->blocks, d->blocks / (2 * 1024));

        mbytes = d->blocks / (2 * 1024);
        if (mbytes > 0)
                printf(" %llu MB.", mbytes);

        printf("\n");
}

/** Register driver and enable device I/O. */
static int ata_bd_init(void)
{
        void *vaddr;
        int rc;

        rc = devmap_driver_register(NAME, ata_bd_connection);
        if (rc < 0) {
                printf(NAME ": Unable to register driver.\n");
                return rc;
        }

        rc = pio_enable((void *) cmd_physical, sizeof(ata_cmd_t), &vaddr);
        if (rc != EOK) {
                printf(NAME ": Could not initialize device I/O space.\n");
                return rc;
        }

        cmd = vaddr;

        rc = pio_enable((void *) ctl_physical, sizeof(ata_ctl_t), &vaddr);
        if (rc != EOK) {
                printf(NAME ": Could not initialize device I/O space.\n");
                return rc;
        }

        ctl = vaddr;


        return EOK;
}

/** Block device connection handler */
static void ata_bd_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        void *fs_va = NULL;
        ipc_callid_t callid;
        ipc_call_t call;
        ipcarg_t method;
        dev_handle_t dh;
        int flags;
        int retval;
        off_t idx;
        size_t size;
        int disk_id, i;

        /* Get the device handle. */
        dh = IPC_GET_ARG1(*icall);

        /* Determine which disk device is the client connecting to. */
        disk_id = -1;
        for (i = 0; i < MAX_DISKS; i++)
                if (disk[i].dev_handle == dh)
                        disk_id = i;

        if (disk_id < 0 || disk[disk_id].present == false) {
                ipc_answer_0(iid, EINVAL);
                return;
        }

        /* Answer the IPC_M_CONNECT_ME_TO call. */
        ipc_answer_0(iid, EOK);

        if (!ipc_share_out_receive(&callid, &comm_size, &flags)) {
                ipc_answer_0(callid, EHANGUP);
                return;
        }

        fs_va = as_get_mappable_page(comm_size);
        if (fs_va == NULL) {
                ipc_answer_0(callid, EHANGUP);
                return;
        }

        (void) ipc_share_out_finalize(callid, fs_va);

        while (1) {
                callid = async_get_call(&call);
                method = IPC_GET_METHOD(call);
                switch (method) {
                case IPC_M_PHONE_HUNGUP:
                        /* The other side has hung up. */
                        ipc_answer_0(callid, EOK);
                        return;
                case BD_READ_BLOCK:
                case BD_WRITE_BLOCK:
                        idx = IPC_GET_ARG1(call);
                        size = IPC_GET_ARG2(call);
                        if (size > comm_size) {
                                retval = EINVAL;
                                break;
                        }
                        retval = ata_bd_rdwr(disk_id, method, idx,
                            size, fs_va);
                        break;
                default:
                        retval = EINVAL;
                        break;
                }
                ipc_answer_0(callid, retval);
        }
}

/** Initialize a disk.
 *
 * Probes for a disk, determines its parameters and initializes
 * the disk structure.
 */
static int disk_init(disk_t *d, int disk_id)
{
        identify_data_t idata;
        uint8_t model[40];
        uint16_t w;
        uint8_t c;
        size_t pos, len;
        int rc;
        int i;

        rc = drive_identify(disk_id, &idata);
        if (rc != EOK) {
                d->present = false;
                return rc;
        }

        if ((idata.caps & cap_lba) == 0) {
                /* Device only supports CHS addressing. */
                d->amode = am_chs;

                d->geom.cylinders = idata.cylinders;
                d->geom.heads = idata.heads;
                d->geom.sectors = idata.sectors;

                d->blocks = d->geom.cylinders * d->geom.heads * d->geom.sectors;
        } else {
                /* Device supports LBA-28. */
                d->amode = am_lba28;

                d->geom.cylinders = 0;
                d->geom.heads = 0;
                d->geom.sectors = 0;

                d->blocks =
                    (uint32_t) idata.total_lba_sec0 | 
                    ((uint32_t) idata.total_lba_sec1 << 16);
        }

        /*
         * Convert model name to string representation.
         */
        for (i = 0; i < 20; i++) {
                w = idata.model_name[i];
                model[2 * i] = w >> 8;
                model[2 * i + 1] = w & 0x00ff;
        }

        len = 40;
        while (len > 0 && model[len - 1] == 0x20)
                --len;

        pos = 0;
        for (i = 0; i < len; ++i) {
                c = model[i];
                if (c >= 0x80) c = '?';

                chr_encode(c, d->model, &pos, 40);
        }
        d->model[pos] = '\0';

        d->present = true;
        fibril_mutex_initialize(&d->lock);

        return EOK;
}

/** Transfer a logical block from/to the device.
 *
 * @param disk_id       Device index (0 or 1)
 * @param method        @c BD_READ_BLOCK or @c BD_WRITE_BLOCK
 * @param blk_idx       Index of the first block.
 * @param size          Size of the logical block.
 * @param buf           Data buffer.
 *
 * @return EOK on success, EIO on error.
 */
static int ata_bd_rdwr(int disk_id, ipcarg_t method, off_t blk_idx, size_t size,
    void *buf)
{
        int rc;
        size_t now;

        while (size > 0) {
                now = size < block_size ? size : block_size;
                if (now != block_size)
                        return EINVAL;

                if (method == BD_READ_BLOCK)
                        rc = ata_bd_read_block(disk_id, blk_idx, 1, buf);
                else
                        rc = ata_bd_write_block(disk_id, blk_idx, 1, buf);

                if (rc != EOK)
                        return rc;

                buf += block_size;
                blk_idx++;

                if (size > block_size)
                        size -= block_size;
                else
                        size = 0;
        }

        return EOK;
}

/** Issue IDENTIFY command.
 *
 * Reads @c identify data into the provided buffer. This is used to detect
 * whether an ATA device is present and if so, to determine its parameters.
 *
 * @param disk_id       Device ID, 0 or 1.
 * @param buf           Pointer to a 512-byte buffer.
 */
static int drive_identify(int disk_id, void *buf)
{
        uint16_t data;
        uint8_t status;
        uint8_t drv_head;
        size_t i;

        drv_head = ((disk_id != 0) ? DHR_DRV : 0);

        if (wait_status(0, ~SR_BSY, NULL, TIMEOUT_PROBE) != EOK)
                return EIO;

        pio_write_8(&cmd->drive_head, drv_head);

        /*
         * This is where we would most likely expect a non-existing device to
         * show up by not setting SR_DRDY.
         */
        if (wait_status(SR_DRDY, ~SR_BSY, NULL, TIMEOUT_PROBE) != EOK)
                return EIO;

        pio_write_8(&cmd->command, CMD_IDENTIFY_DRIVE);

        if (wait_status(0, ~SR_BSY, &status, TIMEOUT_PROBE) != EOK)
                return EIO;

        /* Read data from the disk buffer. */

        if ((status & SR_DRQ) != 0) {
                for (i = 0; i < block_size / 2; i++) {
                        data = pio_read_16(&cmd->data_port);
                        ((uint16_t *) buf)[i] = data;
                }
        }

        if ((status & SR_ERR) != 0)
                return EIO;

        return EOK;
}

/** Read a physical from the device.
 *
 * @param disk_id       Device index (0 or 1)
 * @param blk_idx       Index of the first block.
 * @param blk_cnt       Number of blocks to transfer.
 * @param buf           Buffer for holding the data.
 *
 * @return EOK on success, EIO on error.
 */
static int ata_bd_read_block(int disk_id, uint64_t blk_idx, size_t blk_cnt,
    void *buf)
{
        size_t i;
        uint16_t data;
        uint8_t status;
        uint64_t c, h, s;
        uint64_t idx;
        uint8_t drv_head;
        disk_t *d;

        d = &disk[disk_id];

        /* Check device bounds. */
        if (blk_idx >= d->blocks)
                return EINVAL;

        if (d->amode == am_chs) {
                /* Compute CHS coordinates. */
                c = blk_idx / (d->geom.heads * d->geom.sectors);
                idx = blk_idx % (d->geom.heads * d->geom.sectors);

                h = idx / d->geom.sectors;
                s = 1 + (idx % d->geom.sectors);
        } else {
                /* Compute LBA-28 coordinates. */
                s = blk_idx & 0xff;             /* bits 0-7 */
                c = (blk_idx >> 8) & 0xffff;    /* bits 8-23 */
                h = (blk_idx >> 24) & 0x0f;     /* bits 24-27 */
        }

        /* New value for Drive/Head register */
        drv_head =
            ((disk_id != 0) ? DHR_DRV : 0) |
            ((d->amode != am_chs) ? DHR_LBA : 0) |
            (h & 0x0f);

        fibril_mutex_lock(&d->lock);

        /* Program a Read Sectors operation. */

        if (wait_status(0, ~SR_BSY, NULL, TIMEOUT_BSY) != EOK) {
                fibril_mutex_unlock(&d->lock);
                return EIO;
        }

        pio_write_8(&cmd->drive_head, drv_head);

        if (wait_status(SR_DRDY, ~SR_BSY, NULL, TIMEOUT_DRDY) != EOK) {
                fibril_mutex_unlock(&d->lock);
                return EIO;
        }

        pio_write_8(&cmd->sector_count, 1);
        pio_write_8(&cmd->sector_number, s);
        pio_write_8(&cmd->cylinder_low, c & 0xff);
        pio_write_8(&cmd->cylinder_high, c >> 16);

        pio_write_8(&cmd->command, CMD_READ_SECTORS);

        if (wait_status(0, ~SR_BSY, &status, TIMEOUT_BSY) != EOK) {
                fibril_mutex_unlock(&d->lock);
                return EIO;
        }

        if ((status & SR_DRQ) != 0) {
                /* Read data from the device buffer. */

                for (i = 0; i < block_size / 2; i++) {
                        data = pio_read_16(&cmd->data_port);
                        ((uint16_t *) buf)[i] = data;
                }
        }

        if ((status & SR_ERR) != 0)
                return EIO;

        fibril_mutex_unlock(&d->lock);
        return EOK;
}

/** Write a physical block to the device.
 *
 * @param disk_id       Device index (0 or 1)
 * @param blk_idx       Index of the first block.
 * @param blk_cnt       Number of blocks to transfer.
 * @param buf           Buffer holding the data to write.
 *
 * @return EOK on success, EIO on error.
 */
static int ata_bd_write_block(int disk_id, uint64_t blk_idx, size_t blk_cnt,
    const void *buf)
{
        size_t i;
        uint8_t status;
        uint64_t c, h, s;
        uint64_t idx;
        uint8_t drv_head;
        disk_t *d;

        d = &disk[disk_id];

        /* Check device bounds. */
        if (blk_idx >= d->blocks)
                return EINVAL;

        if (d->amode == am_chs) {
                /* Compute CHS coordinates. */
                c = blk_idx / (d->geom.heads * d->geom.sectors);
                idx = blk_idx % (d->geom.heads * d->geom.sectors);

                h = idx / d->geom.sectors;
                s = 1 + (idx % d->geom.sectors);
        } else {
                /* Compute LBA-28 coordinates. */
                s = blk_idx & 0xff;             /* bits 0-7 */
                c = (blk_idx >> 8) & 0xffff;    /* bits 8-23 */
                h = (blk_idx >> 24) & 0x0f;     /* bits 24-27 */
        }

        /* New value for Drive/Head register */
        drv_head =
            ((disk_id != 0) ? DHR_DRV : 0) |
            ((d->amode != am_chs) ? DHR_LBA : 0) |
            (h & 0x0f);

        fibril_mutex_lock(&d->lock);

        /* Program a Write Sectors operation. */

        if (wait_status(0, ~SR_BSY, NULL, TIMEOUT_BSY) != EOK) {
                fibril_mutex_unlock(&d->lock);
                return EIO;
        }

        pio_write_8(&cmd->drive_head, drv_head);

        if (wait_status(SR_DRDY, ~SR_BSY, NULL, TIMEOUT_DRDY) != EOK) {
                fibril_mutex_unlock(&d->lock);
                return EIO;
        }

        pio_write_8(&cmd->sector_count, 1);
        pio_write_8(&cmd->sector_number, s);
        pio_write_8(&cmd->cylinder_low, c & 0xff);
        pio_write_8(&cmd->cylinder_high, c >> 16);

        pio_write_8(&cmd->command, CMD_WRITE_SECTORS);

        if (wait_status(0, ~SR_BSY, &status, TIMEOUT_BSY) != EOK) {
                fibril_mutex_unlock(&d->lock);
                return EIO;
        }

        if ((status & SR_DRQ) != 0) {
                /* Write data to the device buffer. */

                for (i = 0; i < block_size / 2; i++) {
                        pio_write_16(&cmd->data_port, ((uint16_t *) buf)[i]);
                }
        }

        fibril_mutex_unlock(&d->lock);

        if (status & SR_ERR)
                return EIO;

        return EOK;
}

/** Wait until some status bits are set and some are reset.
 *
 * Example: wait_status(SR_DRDY, ~SR_BSY) waits for SR_DRDY to become
 * set and SR_BSY to become reset.
 *
 * @param set           Combination if bits which must be all set.
 * @param n_reset       Negated combination of bits which must be all reset.
 * @param pstatus       Pointer where to store last read status or NULL.
 * @param timeout       Timeout in 10ms units.
 *
 * @return              EOK on success, EIO on timeout.
 */
static int wait_status(unsigned set, unsigned n_reset, uint8_t *pstatus,
    unsigned timeout)
{
        uint8_t status;
        int cnt;

        status = pio_read_8(&cmd->status);

        /*
         * This is crude, yet simple. First try with 1us delays
         * (most likely the device will respond very fast). If not,
         * start trying every 10 ms.
         */

        cnt = 100;
        while ((status & ~n_reset) != 0 || (status & set) != set) {
                async_usleep(1);
                --cnt;
                if (cnt <= 0) break;

                status = pio_read_8(&cmd->status);
        }

        cnt = timeout;
        while ((status & ~n_reset) != 0 || (status & set) != set) {
                async_usleep(10000);
                --cnt;
                if (cnt <= 0) break;

                status = pio_read_8(&cmd->status);
        }

        if (pstatus)
                *pstatus = status;

        if (cnt == 0)
                return EIO;

        return EOK;
}

/**
 * @}
 */