/*
 * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     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 SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
 * This file contains support for diagnostic functions.  It is accessed by
 * opening the ipath_diag device, normally minor number 129.  Diagnostic use
 * of the InfiniPath chip may render the chip or board unusable until the
 * driver is unloaded, or in some cases, until the system is rebooted.
 *
 * Accesses to the chip through this interface are not similar to going
 * through the /sys/bus/pci resource mmap interface.
 */

#include <linux/io.h>
#include <linux/pci.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
#include <linux/export.h>
#include <asm/uaccess.h>

#include "ipath_kernel.h"
#include "ipath_common.h"

int ipath_diag_inuse;
static int diag_set_link;

static int ipath_diag_open(struct inode *in, struct file *fp);
static int ipath_diag_release(struct inode *in, struct file *fp);
static ssize_t ipath_diag_read(struct file *fp, char __user *data,
                               size_t count, loff_t *off);
static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
                                size_t count, loff_t *off);

static const struct file_operations diag_file_ops = {
        .owner = THIS_MODULE,
        .write = ipath_diag_write,
        .read = ipath_diag_read,
        .open = ipath_diag_open,
        .release = ipath_diag_release,
        .llseek = default_llseek,
};

static ssize_t ipath_diagpkt_write(struct file *fp,
                                   const char __user *data,
                                   size_t count, loff_t *off);

static const struct file_operations diagpkt_file_ops = {
        .owner = THIS_MODULE,
        .write = ipath_diagpkt_write,
        .llseek = noop_llseek,
};

static atomic_t diagpkt_count = ATOMIC_INIT(0);
static struct cdev *diagpkt_cdev;
static struct device *diagpkt_dev;

int ipath_diag_add(struct ipath_devdata *dd)
{
        char name[16];
        int ret = 0;

        if (atomic_inc_return(&diagpkt_count) == 1) {
                ret = ipath_cdev_init(IPATH_DIAGPKT_MINOR,
                                      "ipath_diagpkt", &diagpkt_file_ops,
                                      &diagpkt_cdev, &diagpkt_dev);

                if (ret) {
                        ipath_dev_err(dd, "Couldn't create ipath_diagpkt "
                                      "device: %d", ret);
                        goto done;
                }
        }

        snprintf(name, sizeof(name), "ipath_diag%d", dd->ipath_unit);

        ret = ipath_cdev_init(IPATH_DIAG_MINOR_BASE + dd->ipath_unit, name,
                              &diag_file_ops, &dd->diag_cdev,
                              &dd->diag_dev);
        if (ret)
                ipath_dev_err(dd, "Couldn't create %s device: %d",
                              name, ret);

done:
        return ret;
}

void ipath_diag_remove(struct ipath_devdata *dd)
{
        if (atomic_dec_and_test(&diagpkt_count))
                ipath_cdev_cleanup(&diagpkt_cdev, &diagpkt_dev);

        ipath_cdev_cleanup(&dd->diag_cdev, &dd->diag_dev);
}

/**
 * ipath_read_umem64 - read a 64-bit quantity from the chip into user space
 * @dd: the infinipath device
 * @uaddr: the location to store the data in user memory
 * @caddr: the source chip address (full pointer, not offset)
 * @count: number of bytes to copy (multiple of 32 bits)
 *
 * This function also localizes all chip memory accesses.
 * The copy should be written such that we read full cacheline packets
 * from the chip.  This is usually used for a single qword
 *
 * NOTE:  This assumes the chip address is 64-bit aligned.
 */
static int ipath_read_umem64(struct ipath_devdata *dd, void __user *uaddr,
                             const void __iomem *caddr, size_t count)
{
        const u64 __iomem *reg_addr = caddr;
        const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
        int ret;

        /* not very efficient, but it works for now */
        if (reg_addr < dd->ipath_kregbase || reg_end > dd->ipath_kregend) {
                ret = -EINVAL;
                goto bail;
        }
        while (reg_addr < reg_end) {
                u64 data = readq(reg_addr);
                if (copy_to_user(uaddr, &data, sizeof(u64))) {
                        ret = -EFAULT;
                        goto bail;
                }
                reg_addr++;
                uaddr += sizeof(u64);
        }
        ret = 0;
bail:
        return ret;
}

/**
 * ipath_write_umem64 - write a 64-bit quantity to the chip from user space
 * @dd: the infinipath device
 * @caddr: the destination chip address (full pointer, not offset)
 * @uaddr: the source of the data in user memory
 * @count: the number of bytes to copy (multiple of 32 bits)
 *
 * This is usually used for a single qword
 * NOTE:  This assumes the chip address is 64-bit aligned.
 */

static int ipath_write_umem64(struct ipath_devdata *dd, void __iomem *caddr,
                              const void __user *uaddr, size_t count)
{
        u64 __iomem *reg_addr = caddr;
        const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
        int ret;

        /* not very efficient, but it works for now */
        if (reg_addr < dd->ipath_kregbase || reg_end > dd->ipath_kregend) {
                ret = -EINVAL;
                goto bail;
        }
        while (reg_addr < reg_end) {
                u64 data;
                if (copy_from_user(&data, uaddr, sizeof(data))) {
                        ret = -EFAULT;
                        goto bail;
                }
                writeq(data, reg_addr);

                reg_addr++;
                uaddr += sizeof(u64);
        }
        ret = 0;
bail:
        return ret;
}

/**
 * ipath_read_umem32 - read a 32-bit quantity from the chip into user space
 * @dd: the infinipath device
 * @uaddr: the location to store the data in user memory
 * @caddr: the source chip address (full pointer, not offset)
 * @count: number of bytes to copy
 *
 * read 32 bit values, not 64 bit; for memories that only
 * support 32 bit reads; usually a single dword.
 */
static int ipath_read_umem32(struct ipath_devdata *dd, void __user *uaddr,
                             const void __iomem *caddr, size_t count)
{
        const u32 __iomem *reg_addr = caddr;
        const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
        int ret;

        if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
            reg_end > (u32 __iomem *) dd->ipath_kregend) {
                ret = -EINVAL;
                goto bail;
        }
        /* not very efficient, but it works for now */
        while (reg_addr < reg_end) {
                u32 data = readl(reg_addr);
                if (copy_to_user(uaddr, &data, sizeof(data))) {
                        ret = -EFAULT;
                        goto bail;
                }

                reg_addr++;
                uaddr += sizeof(u32);

        }
        ret = 0;
bail:
        return ret;
}

/**
 * ipath_write_umem32 - write a 32-bit quantity to the chip from user space
 * @dd: the infinipath device
 * @caddr: the destination chip address (full pointer, not offset)
 * @uaddr: the source of the data in user memory
 * @count: number of bytes to copy
 *
 * write 32 bit values, not 64 bit; for memories that only
 * support 32 bit write; usually a single dword.
 */

static int ipath_write_umem32(struct ipath_devdata *dd, void __iomem *caddr,
                              const void __user *uaddr, size_t count)
{
        u32 __iomem *reg_addr = caddr;
        const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
        int ret;

        if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
            reg_end > (u32 __iomem *) dd->ipath_kregend) {
                ret = -EINVAL;
                goto bail;
        }
        while (reg_addr < reg_end) {
                u32 data;
                if (copy_from_user(&data, uaddr, sizeof(data))) {
                        ret = -EFAULT;
                        goto bail;
                }
                writel(data, reg_addr);

                reg_addr++;
                uaddr += sizeof(u32);
        }
        ret = 0;
bail:
        return ret;
}

static int ipath_diag_open(struct inode *in, struct file *fp)
{
        int unit = iminor(in) - IPATH_DIAG_MINOR_BASE;
        struct ipath_devdata *dd;
        int ret;

        mutex_lock(&ipath_mutex);

        if (ipath_diag_inuse) {
                ret = -EBUSY;
                goto bail;
        }

        dd = ipath_lookup(unit);

        if (dd == NULL || !(dd->ipath_flags & IPATH_PRESENT) ||
            !dd->ipath_kregbase) {
                ret = -ENODEV;
                goto bail;
        }

        fp->private_data = dd;
        ipath_diag_inuse = -2;
        diag_set_link = 0;
        ret = 0;

        /* Only expose a way to reset the device if we
           make it into diag mode. */
        ipath_expose_reset(&dd->pcidev->dev);

bail:
        mutex_unlock(&ipath_mutex);

        return ret;
}

/**
 * ipath_diagpkt_write - write an IB packet
 * @fp: the diag data device file pointer
 * @data: ipath_diag_pkt structure saying where to get the packet
 * @count: size of data to write
 * @off: unused by this code
 */
static ssize_t ipath_diagpkt_write(struct file *fp,
                                   const char __user *data,
                                   size_t count, loff_t *off)
{
        u32 __iomem *piobuf;
        u32 plen, clen, pbufn;
        struct ipath_diag_pkt odp;
        struct ipath_diag_xpkt dp;
        u32 *tmpbuf = NULL;
        struct ipath_devdata *dd;
        ssize_t ret = 0;
        u64 val;
        u32 l_state, lt_state; /* LinkState, LinkTrainingState */

        if (count < sizeof(odp)) {
                ret = -EINVAL;
                goto bail;
        }

        if (count == sizeof(dp)) {
                if (copy_from_user(&dp, data, sizeof(dp))) {
                        ret = -EFAULT;
                        goto bail;
                }
        } else if (copy_from_user(&odp, data, sizeof(odp))) {
                ret = -EFAULT;
                goto bail;
        }

        /*
         * Due to padding/alignment issues (lessened with new struct)
         * the old and new structs are the same length. We need to
         * disambiguate them, which we can do because odp.len has never
         * been less than the total of LRH+BTH+DETH so far, while
         * dp.unit (same offset) unit is unlikely to get that high.
         * Similarly, dp.data, the pointer to user at the same offset
         * as odp.unit, is almost certainly at least one (512byte)page
         * "above" NULL. The if-block below can be omitted if compatibility
         * between a new driver and older diagnostic code is unimportant.
         * compatibility the other direction (new diags, old driver) is
         * handled in the diagnostic code, with a warning.
         */
        if (dp.unit >= 20 && dp.data < 512) {
                /* very probable version mismatch. Fix it up */
                memcpy(&odp, &dp, sizeof(odp));
                /* We got a legacy dp, copy elements to dp */
                dp.unit = odp.unit;
                dp.data = odp.data;
                dp.len = odp.len;
                dp.pbc_wd = 0; /* Indicate we need to compute PBC wd */
        }

        /* send count must be an exact number of dwords */
        if (dp.len & 3) {
                ret = -EINVAL;
                goto bail;
        }

        clen = dp.len >> 2;

        dd = ipath_lookup(dp.unit);
        if (!dd || !(dd->ipath_flags & IPATH_PRESENT) ||
            !dd->ipath_kregbase) {
                ipath_cdbg(VERBOSE, "illegal unit %u for diag data send\n",
                           dp.unit);
                ret = -ENODEV;
                goto bail;
        }

        if (ipath_diag_inuse && !diag_set_link &&
            !(dd->ipath_flags & IPATH_LINKACTIVE)) {
                diag_set_link = 1;
                ipath_cdbg(VERBOSE, "Trying to set to set link active for "
                           "diag pkt\n");
                ipath_set_linkstate(dd, IPATH_IB_LINKARM);
                ipath_set_linkstate(dd, IPATH_IB_LINKACTIVE);
        }

        if (!(dd->ipath_flags & IPATH_INITTED)) {
                /* no hardware, freeze, etc. */
                ipath_cdbg(VERBOSE, "unit %u not usable\n", dd->ipath_unit);
                ret = -ENODEV;
                goto bail;
        }
        /*
         * Want to skip check for l_state if using custom PBC,
         * because we might be trying to force an SM packet out.
         * first-cut, skip _all_ state checking in that case.
         */
        val = ipath_ib_state(dd, dd->ipath_lastibcstat);
        lt_state = ipath_ib_linktrstate(dd, dd->ipath_lastibcstat);
        l_state = ipath_ib_linkstate(dd, dd->ipath_lastibcstat);
        if (!dp.pbc_wd && (lt_state != INFINIPATH_IBCS_LT_STATE_LINKUP ||
            (val != dd->ib_init && val != dd->ib_arm &&
            val != dd->ib_active))) {
                ipath_cdbg(VERBOSE, "unit %u not ready (state %llx)\n",
                           dd->ipath_unit, (unsigned long long) val);
                ret = -EINVAL;
                goto bail;
        }

        /* need total length before first word written */
        /* +1 word is for the qword padding */
        plen = sizeof(u32) + dp.len;

        if ((plen + 4) > dd->ipath_ibmaxlen) {
                ipath_dbg("Pkt len 0x%x > ibmaxlen %x\n",
                          plen - 4, dd->ipath_ibmaxlen);
                ret = -EINVAL;
                goto bail;      /* before writing pbc */
        }
        tmpbuf = vmalloc(plen);
        if (!tmpbuf) {
                dev_info(&dd->pcidev->dev, "Unable to allocate tmp buffer, "
                         "failing\n");
                ret = -ENOMEM;
                goto bail;
        }

        if (copy_from_user(tmpbuf,
                           (const void __user *) (unsigned long) dp.data,
                           dp.len)) {
                ret = -EFAULT;
                goto bail;
        }

        plen >>= 2;             /* in dwords */

        piobuf = ipath_getpiobuf(dd, plen, &pbufn);
        if (!piobuf) {
                ipath_cdbg(VERBOSE, "No PIO buffers avail unit for %u\n",
                           dd->ipath_unit);
                ret = -EBUSY;
                goto bail;
        }
        /* disarm it just to be extra sure */
        ipath_disarm_piobufs(dd, pbufn, 1);

        if (ipath_debug & __IPATH_PKTDBG)
                ipath_cdbg(VERBOSE, "unit %u 0x%x+1w pio%d\n",
                           dd->ipath_unit, plen - 1, pbufn);

        if (dp.pbc_wd == 0)
                dp.pbc_wd = plen;
        writeq(dp.pbc_wd, piobuf);
        /*
         * Copy all by the trigger word, then flush, so it's written
         * to chip before trigger word, then write trigger word, then
         * flush again, so packet is sent.
         */
        if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
                ipath_flush_wc();
                __iowrite32_copy(piobuf + 2, tmpbuf, clen - 1);
                ipath_flush_wc();
                __raw_writel(tmpbuf[clen - 1], piobuf + clen + 1);
        } else
                __iowrite32_copy(piobuf + 2, tmpbuf, clen);

        ipath_flush_wc();

        ret = sizeof(dp);

bail:
        vfree(tmpbuf);
        return ret;
}

static int ipath_diag_release(struct inode *in, struct file *fp)
{
        mutex_lock(&ipath_mutex);
        ipath_diag_inuse = 0;
        fp->private_data = NULL;
        mutex_unlock(&ipath_mutex);
        return 0;
}

static ssize_t ipath_diag_read(struct file *fp, char __user *data,
                               size_t count, loff_t *off)
{
        struct ipath_devdata *dd = fp->private_data;
        void __iomem *kreg_base;
        ssize_t ret;

        kreg_base = dd->ipath_kregbase;

        if (count == 0)
                ret = 0;
        else if ((count % 4) || (*off % 4))
                /* address or length is not 32-bit aligned, hence invalid */
                ret = -EINVAL;
        else if (ipath_diag_inuse < 1 && (*off || count != 8))
                ret = -EINVAL;  /* prevent cat /dev/ipath_diag* */
        else if ((count % 8) || (*off % 8))
                /* address or length not 64-bit aligned; do 32-bit reads */
                ret = ipath_read_umem32(dd, data, kreg_base + *off, count);
        else
                ret = ipath_read_umem64(dd, data, kreg_base + *off, count);

        if (ret >= 0) {
                *off += count;
                ret = count;
                if (ipath_diag_inuse == -2)
                        ipath_diag_inuse++;
        }

        return ret;
}

static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
                                size_t count, loff_t *off)
{
        struct ipath_devdata *dd = fp->private_data;
        void __iomem *kreg_base;
        ssize_t ret;

        kreg_base = dd->ipath_kregbase;

        if (count == 0)
                ret = 0;
        else if ((count % 4) || (*off % 4))
                /* address or length is not 32-bit aligned, hence invalid */
                ret = -EINVAL;
        else if ((ipath_diag_inuse == -1 && (*off || count != 8)) ||
                 ipath_diag_inuse == -2)  /* read qw off 0, write qw off 0 */
                ret = -EINVAL;  /* before any other write allowed */
        else if ((count % 8) || (*off % 8))
                /* address or length not 64-bit aligned; do 32-bit writes */
                ret = ipath_write_umem32(dd, kreg_base + *off, data, count);
        else
                ret = ipath_write_umem64(dd, kreg_base + *off, data, count);

        if (ret >= 0) {
                *off += count;
                ret = count;
                if (ipath_diag_inuse == -1)
                        ipath_diag_inuse = 1; /* all read/write OK now */
        }

        return ret;
}