vm: fix a null dereference on out-of-memory

[minix.git] / drivers / mmc / mmcblk.c

/*
 * Block driver for Multi Media Cards (MMC).
 */
/* kernel headers */
#include <minix/syslib.h>
#include <minix/driver.h>
#include <minix/blockdriver.h>
#include <minix/drvlib.h>

/* system headers */
#include <sys/ioc_disk.h>       /* disk IOCTL's */

/* usr headers */
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <signal.h>

/* local headers */
#include "mmchost.h"
#include "mmclog.h"

/* used for logging */
static struct mmclog log = {
        .name = "mmc_block",
        .log_level = LEVEL_DEBUG,
        .log_func = default_log
};

/* holding the current host controller */
static struct mmc_host host;

/*@TODO REMOVE THIS */
void
read_tsc_64(u64_t * t)
{
}

u32_t
tsc_64_to_micros(u64_t tsc)
{
        return 0;
}

#define SUB_PER_DRIVE           (NR_PARTITIONS * NR_PARTITIONS)
#define NR_SUBDEVS              (MAX_DRIVES * SUB_PER_DRIVE)

/* When passing data over a grant one needs to pass
 * a buffer to sys_safecopy copybuff is used for that*/
#define COPYBUFF_SIZE 0x1000    /* 4k buff */
static unsigned char copybuff[COPYBUFF_SIZE];

static struct sd_slot *get_slot(dev_t minor);

/* Prototypes for the block device */
static int block_open(dev_t minor, int access);
static int block_close(dev_t minor);
static int block_transfer(dev_t minor,
    int do_write,
    u64_t position,
    endpoint_t endpt, iovec_t * iov, unsigned int nr_req, int flags);

static int block_ioctl(dev_t minor,
    unsigned int request, endpoint_t endpt, cp_grant_id_t grant);
static struct device *block_part(dev_t minor);

/* System even handling */
static void sef_local_startup();
static int block_system_event_cb(int type, sef_init_info_t * info);
static void block_signal_handler_cb(int signo);

static int apply_env();

#if 0
/* set the global logging level */
static void set_log_level(int level);
#endif

/* Entry points for the BLOCK driver. */
static struct blockdriver mmc_driver = {
        BLOCKDRIVER_TYPE_DISK,  /* handle partition requests */
        block_open,             /* open or mount */
        block_close,            /* on a close */
        block_transfer,         /* does the I/O */
        block_ioctl,            /* ioclt's */
        NULL,                   /* no need to clean up (yet) */
        block_part,             /* return partition information */
        NULL,                   /* no geometry */
        NULL,                   /* no interrupt processing */
        NULL,                   /* no alarm processing */
        NULL,                   /* no processing of other messages */
        NULL                    /* no threading support */
};

static int
apply_env()
{
        /* apply the env setting passed to this driver parameters accepted
         * log_level=[0-4] (NONE,WARNING,INFO,DEBUG,TRACE) instance=[0-3]
         * instance/bus number to use for this driver Passing these arguments
         * is done when starting the driver using the service command in the
         * following way service up /sbin/mmc -args "log_level=2 instance=1 
         * driver=dummy" -dev /dev/c2d0 */
        char driver[16];
        memset(driver, '\0', 16);
        (void) env_get_param("driver", driver, 16);
        if (strlen(driver) == 0
            || strncmp(driver, "mmchs", strlen("mmchs") + 1) == 0) {
                /* early init of host mmc host controller. This code should
                 * depend on knowing the hardware that is running bellow. */
                host_initialize_host_structure_mmchs(&host);
        } else if (strncmp(driver, "dummy", strlen("dummy") + 1) == 0) {
                host_initialize_host_structure_dummy(&host);
        } else {
                mmc_log_warn(&log, "Unknown driver %s\n", driver);
        }
#if 0
        long v;
        /* The following code(env_parse) uses strtol.c and needs __aeabi_idiv */
        /* @TODO: re-enable this function when __aeabi_idiv will be present */
        /* Initialize the verbosity level. */
        v = 0;
        if (env_parse("log_level", "d", 0, &v, LEVEL_NONE,
                LEVEL_TRACE) == EP_SET) {
                set_log_level(v);
        }

        /* Find out which driver instance we are. */
        v = 0;
        env_parse("instance", "d", 0, &v, 0, 3);
        if (host.host_set_instance(&host, v)) {
                mmc_log_warn(&log, "Failed to set mmc instance to  %d\n", v);
                return -1;      /* NOT OK */
        }
#endif
        return OK;
}

;

/*===========================================================================*
 *                    block_open                                             *
 *===========================================================================*/
static int
block_open(dev_t minor, int access)
{
        struct sd_slot *slot;
        slot = get_slot(minor);
        int i, j;
        int part_count, sub_part_count;

        i = j = part_count = sub_part_count = 0;

        if (!slot) {
                mmc_log_debug(&log,
                    "Not handling open on non existing slot\n");
                return EIO;
        }

        assert(slot->host != NULL);

        if (!slot->host->card_detect(slot)) {
                mmc_log_debug(&log, "No card inserted in the SD slot\n");
                return EIO;
        }

        /* If we are already open just increase the open count and return */
        if (slot->card.state == SD_MODE_DATA_TRANSFER_MODE) {
                assert(slot->card.open_ct >= 0);
                slot->card.open_ct++;
                mmc_log_trace(&log, "increased open count to %d\n",
                    slot->card.open_ct);
                return OK;
        }

        /* We did not have an sd-card inserted so we are going to probe for it 
         */
        mmc_log_debug(&log, "First open on (%d)\n", minor);
        if (!host.card_initialize(slot)) {
                // * TODO: set card state to INVALID until removed? */
                return EIO;
        }

        partition(&mmc_driver, 0 /* first card on bus */ , P_PRIMARY,
            0 /* atapi device?? */ );

        mmc_log_debug(&log, "descr \toffset(bytes)      size(bytes)\n", minor);

        mmc_log_debug(&log, "disk %d\t0x%016llx 0x%016llx\n", i,
            slot->card.part[0].dv_base, slot->card.part[0].dv_size);
        for (i = 1; i < 5; i++) {
                if (slot->card.part[i].dv_size == 0)
                        continue;
                part_count++;
                mmc_log_debug(&log, "part %d\t0x%016llx 0x%016llx\n", i,
                    slot->card.part[i].dv_base, slot->card.part[i].dv_size);
                for (j = 0; j < 4; j++) {
                        if (slot->card.subpart[(i - 1) * 4 + j].dv_size == 0)
                                continue;
                        sub_part_count++;
                        mmc_log_debug(&log,
                            " sub %d/%d\t0x%016llx 0x%016llx\n", i, j,
                            slot->card.subpart[(i - 1) * 4 + j].dv_base,
                            slot->card.subpart[(i - 1) * 4 + j].dv_size);
                }
        }
        mmc_log_info(&log, "Found %d partitions and %d sub partitions\n",
            part_count, sub_part_count);
        slot->card.open_ct++;
        assert(slot->card.open_ct == 1);
        return OK;
}

/*===========================================================================*
 *                    block_close                                            *
 *===========================================================================*/
static int
block_close(dev_t minor)
{
        struct sd_slot *slot;

        slot = get_slot(minor);
        if (!slot) {
                mmc_log_debug(&log,
                    "Not handling open on non existing slot\n");
                return EIO;
        }

        /* if we arrived here we expect a card to be present, we will need do
         * deal with removal later */
        assert(slot->host != NULL);
        assert(slot->card.open_ct >= 1);

        /* If this is not the last open count simply decrease the counter and
         * return */
        if (slot->card.open_ct > 1) {
                slot->card.open_ct--;
                mmc_log_trace(&log, "decreased open count to %d\n",
                    slot->card.open_ct);
                return OK;
        }

        assert(slot->card.open_ct == 1);
        mmc_log_debug(&log,
            "freeing the block device as it is no longer used\n");

        /* release the card as check the open_ct should be 0 */
        slot->host->card_release(&slot->card);
        assert(slot->card.open_ct == 0);
        return OK;
}

static int
copyto(endpoint_t dst_e,
    cp_grant_id_t gr_id, vir_bytes offset, vir_bytes address, size_t bytes)
{
        /* Helper function that used memcpy to copy data when the endpoint ==
         * SELF */
        if (dst_e == SELF) {
                memcpy((char *) gr_id + offset, (char *) address, bytes);
                return OK;
        } else {
                /* Read io_size bytes from our data at the correct * offset
                 * and write it to the output buffer at 0 */
                return sys_safecopyto(dst_e, gr_id, offset, address, bytes);
        }
}

static int
copyfrom(endpoint_t src_e,
    cp_grant_id_t gr_id, vir_bytes offset, vir_bytes address, size_t bytes)
{
        /* Helper function that used memcpy to copy data when the endpoint ==
         * SELF */
        if (src_e == SELF) {
                memcpy((char *) address, (char *) gr_id + offset, bytes);
                return OK;
        } else {
                return sys_safecopyfrom(src_e, gr_id, offset, address, bytes);
        }
}

/*===========================================================================*
 *                    block_transfer                                         *
 *===========================================================================*/
static int
block_transfer(dev_t minor,     /* minor device number */
    int do_write,               /* read or write? */
    u64_t position,             /* offset on device to read or write */
    endpoint_t endpt,           /* process doing the request */
    iovec_t * iov,              /* pointer to read or write request vector */
    unsigned int nr_req,        /* length of request vector */
    int flags                   /* transfer flags */
    )
{
        unsigned long counter;
        iovec_t *ciov;          /* Current IO Vector */
        struct device *dev;     /* The device used */
        struct sd_slot *slot;   /* The sd slot the requests is pointed to */
        vir_bytes io_size;      /* Size to read/write to/from the iov */
        vir_bytes io_offset;    /* Size to read/write to/from the iov */
        vir_bytes bytes_written;

        int r, blk_size, i;

        /* Get the current "device" geometry */
        dev = block_part(minor);
        if (dev == NULL) {
                mmc_log_warn(&log,
                    "Transfer requested on unknown device minor(%d)\n", minor);
                /* Unknown device */
                return ENXIO;
        }
        mmc_log_trace(&log, "I/O %d %s 0x%llx\n", minor,
            (do_write) ? "Write" : "Read", position);

        slot = get_slot(minor);
        assert(slot);

        if (slot->card.blk_size == 0) {
                mmc_log_warn(&log, "Request on a card with block size of 0\n");
                return EINVAL;
        }
        if (slot->card.blk_size > COPYBUFF_SIZE) {
                mmc_log_warn(&log,
                    "Card block size (%d) exceeds internal buffer size %d\n",
                    slot->card.blk_size, COPYBUFF_SIZE);
                return EINVAL;
        }

        /* It is fully up to the driver to decide on restrictions for the
         * parameters of transfers, in those cases we return EINVAL */
        if (position % slot->card.blk_size != 0) {
                /* Starting at a block boundary */
                mmc_log_warn(&log,
                    "Requests must start at a block boundary"
                    "(start,block size)=(%016llx,%08x)\n", position,
                    slot->card.blk_size);
                return EINVAL;
        }

        blk_size = slot->card.blk_size;

        bytes_written = 0;

        /* Are we trying to start reading past the end */
        if (position >= dev->dv_size) {
                mmc_log_warn(&log, "start reading past drive size\n");
                return 0;
        };

        ciov = iov;
        /* do some more validation */
        for (counter = 0; counter < nr_req; counter++) {
                assert(ciov != NULL);
                if (ciov->iov_size % blk_size != 0) {
                        /* transfer a multiple of blk_size */
                        mmc_log_warn(&log,
                            "Requests must start at a block boundary "
                            "(start,block size)=(%016llx,%08x)\n", position,
                            slot->card.blk_size);
                        return EINVAL;
                }

                if (ciov->iov_size <= 0) {
                        mmc_log_warn(&log,
                            "Invalid iov size for iov %d of %d size\n",
                            counter, nr_req, ciov->iov_size);
                        return EINVAL;
                }
                ciov++;
        }

        ciov = iov;
        for (counter = 0; counter < nr_req; counter++) {
                /* Assume we are to transfer the amount of data given in the
                 * input/output vector but ensure we are not doing i/o past
                 * our own boundaries */
                io_size = ciov->iov_size;
                io_offset = position + bytes_written;

                /* Check we are not reading/writing past the end */
                if (position + bytes_written + io_size > dev->dv_size) {
                        io_size = dev->dv_size - (position + bytes_written);
                };

                mmc_log_trace(&log,
                    "I/O %s request(%d/%d) iov(grant,size,iosize,"
                    "offset)=(%d,%d,%d,%d)\n",
                    (do_write) ? "write" : "read", counter + 1, nr_req,
                    ciov->iov_addr, ciov->iov_size, io_size, io_offset);
                /* transfer max one block at the time */
                for (i = 0; i < io_size / blk_size; i++) {
                        if (do_write) {
                                /* Read io_size bytes from i/o vector starting
                                 * at 0 and write it to out buffer at the
                                 * correct offset */
                                r = copyfrom(endpt, ciov->iov_addr,
                                    i * blk_size, (vir_bytes) copybuff,
                                    blk_size);
                                if (r != OK) {
                                        mmc_log_warn(&log,
                                            "I/O write error: %s iov(base,size)=(%d,%d)"
                                            " at offset=%d\n",
                                            strerror(_SIGN r), ciov->iov_addr,
                                            ciov->iov_size, io_offset);
                                        return EINVAL;
                                }

                                /* write a single block */
                                slot->host->write(&slot->card,
                                    (dev->dv_base / blk_size) +
                                    (io_offset / blk_size) + i, 1, copybuff);
                                bytes_written += blk_size;
                        } else {
                                /* read a single block info copybuff */
                                slot->host->read(&slot->card,
                                    (dev->dv_base / blk_size) +
                                    (io_offset / blk_size) + i, 1, copybuff);
                                /* Read io_size bytes from our data at the
                                 * correct offset and write it to the output
                                 * buffer at 0 */
                                r = copyto(endpt, ciov->iov_addr, i * blk_size,
                                    (vir_bytes) copybuff, blk_size);
                                if (r != OK) {
                                        mmc_log_warn(&log,
                                            "I/O read error: %s iov(base,size)=(%d,%d)"
                                            " at offset=%d\n",
                                            strerror(_SIGN r), ciov->iov_addr,
                                            ciov->iov_size, io_offset);
                                        return EINVAL;
                                }
                                bytes_written += blk_size;
                        }
                }
                ciov++;
        }
        return bytes_written;
}

/*===========================================================================*
 *                              block_ioctl                                  *
 *===========================================================================*/
static int
block_ioctl(dev_t minor,
    unsigned int request, endpoint_t endpt, cp_grant_id_t grant)
{
        /* IOCTL handling */
        struct sd_slot *slot;
        mmc_log_trace(&log,
            "enter (minor,request,endpoint,grant)=(%d,%lu,%d)\n", minor,
            request, endpt, grant);

        slot = get_slot(minor);
        if (!slot) {
                mmc_log_warn(&log,
                    "Doing ioctl on non existing block device(%d)\n", minor);
                return EINVAL;
        }

        switch (request) {
        case DIOCOPENCT:
                // TODO: add a check for card validity */
                mmc_log_trace(&log, "returning open count %d\n",
                    slot->card.open_ct);
                /* return the current open count */
                return sys_safecopyto(endpt, grant, 0,
                    (vir_bytes) & slot->card.open_ct,
                    sizeof(slot->card.open_ct));
        case DIOCFLUSH:
                /* No need to flush but some devices like movinands require
                 * 500 ms inactivity */
                return OK;
        }

        return EINVAL;
}

/*===========================================================================*
 *                    block_part                                             *
 *===========================================================================*/
static struct device *
block_part(dev_t minor)
{
        /* 
         * Reuse the existing MINIX major/minor partitioning scheme.
         * - 8 drives
         * - 5 devices per drive allowing direct access to the disk and up to 4
         *   partitions (IBM style partitioning without extended partitions)
         * - 4 Minix style sub partitions per partitions
         */
        struct device *dev;
        struct sd_slot *slot;

        dev = NULL;
        slot = get_slot(minor);
        if (!slot) {
                mmc_log_warn(&log,
                    "Device information requested for non existing partition "
                    "minor(%d)\n", minor);
                return NULL;
        }

        if (!slot->host->card_detect(slot)) {
                mmc_log_warn(&log,
                    "Device information requested from empty slot(%d)\n",
                    minor);
                return NULL;
        }

        if (minor < 5) {
                /* we are talking about the first disk */
                dev = &slot->card.part[minor];
                mmc_log_trace(&log,
                    "returning partition(%d) (base,size)=(0x%016llx,0x%016llx)\n",
                    minor, dev->dv_base, dev->dv_size);
        } else if (minor >= 128 && minor < 128 + 16) {
                /* sub partitions of the first disk we don't care about the
                 * rest */
                dev = &slot->card.subpart[minor - 128];
                mmc_log_trace(&log,
                    "returning sub partition(%d) (base,size)=(0x%016llx,0x%016llx)\n",
                    minor - 128, dev->dv_base, dev->dv_size);

        } else {
                mmc_log_warn(&log,
                    "Device information requested for non existing "
                    "partition minor(%d)\n", minor);
        }
        return dev;
}

/*===========================================================================*
 *                         sef_local_startup                                 *
 *===========================================================================*/
static void
sef_local_startup()
{
        mmc_log_info(&log, "Initializing the MMC block device\n");
        if (apply_env()) {
                mmc_log_warn(&log,
                    "Failed while applying environment settings\n");
                exit(EXIT_FAILURE);
        }

        if (host.host_init(&host)) {
                mmc_log_warn(&log,
                    "Failed to initialize the host controller\n");
                exit(EXIT_FAILURE);
        }
        /* 
         * Register callbacks for fresh start, live update and restart.
         *  Use the same function for all event types
         */
        sef_setcb_init_fresh(block_system_event_cb);
        sef_setcb_init_lu(block_system_event_cb);

        /* Register a signal handler */
        sef_setcb_signal_handler(block_signal_handler_cb);

        /* SEF startup */
        sef_startup();
}

/*===========================================================================*
 *                         block_system_event_cb                             *
 *===========================================================================*/
static int
block_system_event_cb(int type, sef_init_info_t * info)
{
        /* 
         * Callbacks for the System event framework as registered in 
         * sef_local_startup */
        switch (type) {
        case SEF_INIT_FRESH:
                mmc_log_info(&log, "System event framework fresh start\n");
                break;

        case SEF_INIT_LU:
                /* Restore the state. post update */
                mmc_log_info(&log, "System event framework live update\n");
                break;

        case SEF_INIT_RESTART:
                mmc_log_info(&log, "System event framework post restart\n");
                break;
        }
        blockdriver_announce(type);
        return OK;
}

/*===========================================================================*
 *                         block_signal_handler_cb                           *
 *===========================================================================*/
static void
block_signal_handler_cb(int signo)
{
        mmc_log_debug(&log, "System event framework signal handler sig(%d)\n",
            signo);
        /* Only check for termination signal, ignore anything else. */
        if (signo != SIGTERM)
                return;
        // FIXME shutdown
        exit(0);
}

#define IS_MINIX_SUB_PARTITION_MINOR(minor) (minor >= MINOR_d0p0s0 )

static struct sd_slot *
get_slot(dev_t minor)
{
        /* 
         * Get an sd_slot based on the minor number.
         *
         * This driver only supports a single card at at time. Also as
         * we are following the major/minor scheme of other driver we
         * must return a slot for all minors on disk 0 these are  0-5
         * for the disk and 4 main partitions and
         * number 128 till 144 for sub partitions.
         */
        /* If this is a minor for the first disk (e.g. minor 0 till 5) */
        if (minor / DEV_PER_DRIVE == 0) {
                /* we are talking about the first disk and that is all we
                 * support */
                return &host.slot[0];
        } else if (IS_MINIX_SUB_PARTITION_MINOR(minor)
            && (((minor - MINOR_d0p0s0) / SUB_PER_DRIVE) == 0)) {
                /* a minor from the first disk */
                return &host.slot[0];
        } else {
                mmc_log_trace(&log,
                    "Device information requested for non existing partition "
                    "minor(%d)\n", minor);
                return NULL;
        }
}

#if 0
static void
set_log_level(int level)
{
        if (level < 0 || level >= 4) {
                return;
        }
        mmc_log_debug(&log, "Setting verbosity level to %d\n", level);
        log.log_level = level;
        if (host.set_log_level) {
                host.set_log_level(level);
        }
}
#endif

int
main(int argc, char **argv)
{

        /* Set and apply the environment */
        env_setargs(argc, argv);

        sef_local_startup();
        blockdriver_task(&mmc_driver);
        return EXIT_SUCCESS;
}