gxe_bd.c

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/*
 * 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.
 */

#include <stdio.h>
#include <libarch/ddi.h>
#include <ddi.h>
#include <ipc/bd.h>
#include <async.h>
#include <as.h>
#include <fibril_synch.h>
#include <devmap.h>
#include <sys/types.h>
#include <errno.h>
#include <macros.h>
#include <task.h>

#define NAME       "gxe_bd"
#define NAMESPACE  "bd"

enum {
        CTL_READ_START  = 0,
        CTL_WRITE_START = 1,
};

enum {
        STATUS_FAILURE  = 0
};

enum {
        MAX_DISKS       = 2
};

typedef struct {
        uint32_t offset_lo;
        uint32_t pad0;
        uint32_t offset_hi;
        uint32_t pad1;

        uint32_t disk_id;
        uint32_t pad2[3];

        uint32_t control;
        uint32_t pad3[3];

        uint32_t status;

        uint32_t pad4[3];
        uint8_t pad5[0x3fc0];

        uint8_t buffer[512];
} gxe_bd_t;


static const size_t block_size = 512;
static size_t comm_size;

static uintptr_t dev_physical = 0x13000000;
static gxe_bd_t *dev;

static devmap_handle_t devmap_handle[MAX_DISKS];

static fibril_mutex_t dev_lock[MAX_DISKS];

static int gxe_bd_init(void);
static void gxe_bd_connection(ipc_callid_t iid, ipc_call_t *icall);
static int gxe_bd_read_blocks(int disk_id, uint64_t ba, unsigned cnt,
    void *buf);
static int gxe_bd_write_blocks(int disk_id, uint64_t ba, unsigned cnt,
    const void *buf);
static int gxe_bd_read_block(int disk_id, uint64_t ba, void *buf);
static int gxe_bd_write_block(int disk_id, uint64_t ba, const void *buf);

int main(int argc, char **argv)
{
        printf(NAME ": GXemul disk driver\n");

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

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

        /* Not reached */
        return 0;
}

static int gxe_bd_init(void)
{
        void *vaddr;
        int rc, i;
        char name[16];

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

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

        dev = vaddr;

        for (i = 0; i < MAX_DISKS; i++) {
                snprintf(name, 16, "%s/disk%d", NAMESPACE, i);
                rc = devmap_device_register(name, &devmap_handle[i]);
                if (rc != EOK) {
                        printf(NAME ": Unable to register device %s.\n", name);
                        return rc;
                }
                fibril_mutex_initialize(&dev_lock[i]);
        }

        return EOK;
}

static void gxe_bd_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        void *fs_va = NULL;
        ipc_callid_t callid;
        ipc_call_t call;
        sysarg_t method;
        devmap_handle_t dh;
        unsigned int flags;
        int retval;
        uint64_t ba;
        unsigned cnt;
        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 (devmap_handle[i] == dh)
                        disk_id = i;

        if (disk_id < 0) {
                async_answer_0(iid, EINVAL);
                return;
        }

        /* Answer the IPC_M_CONNECT_ME_TO call. */
        async_answer_0(iid, EOK);

        if (!async_share_out_receive(&callid, &comm_size, &flags)) {
                async_answer_0(callid, EHANGUP);
                return;
        }

        if (comm_size < block_size) {
                async_answer_0(callid, EHANGUP);
                return;
        }

        fs_va = as_get_mappable_page(comm_size);
        if (fs_va == NULL) {
                async_answer_0(callid, EHANGUP);
                return;
        }

        (void) async_share_out_finalize(callid, fs_va);

        while (1) {
                callid = async_get_call(&call);
                method = IPC_GET_IMETHOD(call);
                switch (method) {
                case IPC_M_PHONE_HUNGUP:
                        /* The other side has hung up. */
                        async_answer_0(callid, EOK);
                        return;
                case BD_READ_BLOCKS:
                        ba = MERGE_LOUP32(IPC_GET_ARG1(call),
                            IPC_GET_ARG2(call));
                        cnt = IPC_GET_ARG3(call);
                        if (cnt * block_size > comm_size) {
                                retval = ELIMIT;
                                break;
                        }
                        retval = gxe_bd_read_blocks(disk_id, ba, cnt, fs_va);
                        break;
                case BD_WRITE_BLOCKS:
                        ba = MERGE_LOUP32(IPC_GET_ARG1(call),
                            IPC_GET_ARG2(call));
                        cnt = IPC_GET_ARG3(call);
                        if (cnt * block_size > comm_size) {
                                retval = ELIMIT;
                                break;
                        }
                        retval = gxe_bd_write_blocks(disk_id, ba, cnt, fs_va);
                        break;
                case BD_GET_BLOCK_SIZE:
                        async_answer_1(callid, EOK, block_size);
                        continue;
                case BD_GET_NUM_BLOCKS:
                        retval = ENOTSUP;
                        break;
                default:
                        retval = EINVAL;
                        break;
                }
                async_answer_0(callid, retval);
        }
}

static int gxe_bd_read_blocks(int disk_id, uint64_t ba, unsigned cnt,
    void *buf) {

        int rc;

        while (cnt > 0) {
                rc = gxe_bd_read_block(disk_id, ba, buf);
                if (rc != EOK)
                        return rc;

                ++ba;
                --cnt;
                buf += block_size;
        }

        return EOK;
}

static int gxe_bd_write_blocks(int disk_id, uint64_t ba, unsigned cnt,
    const void *buf) {

        int rc;

        while (cnt > 0) {
                rc = gxe_bd_write_block(disk_id, ba, buf);
                if (rc != EOK)
                        return rc;

                ++ba;
                --cnt;
                buf += block_size;
        }

        return EOK;
}

static int gxe_bd_read_block(int disk_id, uint64_t ba, void *buf)
{
        uint32_t status;
        uint64_t byte_addr;
        size_t i;
        uint32_t w;

        byte_addr = ba * block_size;

        fibril_mutex_lock(&dev_lock[disk_id]);
        pio_write_32(&dev->offset_lo, (uint32_t) byte_addr);
        pio_write_32(&dev->offset_hi, byte_addr >> 32);
        pio_write_32(&dev->disk_id, disk_id);
        pio_write_32(&dev->control, CTL_READ_START);

        status = pio_read_32(&dev->status);
        if (status == STATUS_FAILURE) {
                fibril_mutex_unlock(&dev_lock[disk_id]);
                return EIO;
        }

        for (i = 0; i < block_size; i++) {
                ((uint8_t *) buf)[i] = w = pio_read_8(&dev->buffer[i]);
        }

        fibril_mutex_unlock(&dev_lock[disk_id]);
        return EOK;
}

static int gxe_bd_write_block(int disk_id, uint64_t ba, const void *buf)
{
        uint32_t status;
        uint64_t byte_addr;
        size_t i;

        byte_addr = ba * block_size;

        fibril_mutex_lock(&dev_lock[disk_id]);

        for (i = 0; i < block_size; i++) {
                pio_write_8(&dev->buffer[i], ((const uint8_t *) buf)[i]);
        }

        pio_write_32(&dev->offset_lo, (uint32_t) byte_addr);
        pio_write_32(&dev->offset_hi, byte_addr >> 32);
        pio_write_32(&dev->disk_id, disk_id);
        pio_write_32(&dev->control, CTL_WRITE_START);

        status = pio_read_32(&dev->status);
        if (status == STATUS_FAILURE) {
                fibril_mutex_unlock(&dev_lock[disk_id]);
                return EIO;
        }

        fibril_mutex_unlock(&dev_lock[disk_id]);
        return EOK;
}

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