/*
 * Copyright (c) 2015, AVAGO Tech. All rights reserved. Author: Marian Choy
 * Copyright (c) 2014, LSI Corp. All rights reserved. Author: Marian Choy
 * Support: freebsdraid@avagotech.com
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer. 2. 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. 3. Neither the name of the
 * <ORGANIZATION> nor the names of its contributors may be used to endorse or
 * promote products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER OR CONTRIBUTORS 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.
 *
 * The views and conclusions contained in the software and documentation are
 * those of the authors and should not be interpreted as representing
 * official policies,either expressed or implied, of the FreeBSD Project.
 *
 * Send feedback to: <megaraidfbsd@avagotech.com> Mail to: AVAGO TECHNOLOGIES, 1621
 * Barber Lane, Milpitas, CA 95035 ATTN: MegaRaid FreeBSD
 *
 */

#include <sys/cdefs.h>
#include <sys/abi_compat.h>
#include <dev/mrsas/mrsas.h>
#include <dev/mrsas/mrsas_ioctl.h>

struct mrsas_passthru_cmd {
        struct mrsas_sge64 *kern_sge;
        struct mrsas_softc *sc;
        struct mrsas_mfi_cmd *cmd;
        bus_dma_tag_t ioctl_data_tag;
        bus_dmamap_t ioctl_data_dmamap;

        u_int32_t error_code;
        u_int32_t sge_count;
        int complete;
};

/*
 * Function prototypes
 */
int     mrsas_alloc_mfi_cmds(struct mrsas_softc *sc);
int     mrsas_passthru(struct mrsas_softc *sc, void *arg, u_long ioctlCmd);
void    mrsas_free_ioc_cmd(struct mrsas_softc *sc);
void    mrsas_free_frame(struct mrsas_softc *sc, struct mrsas_mfi_cmd *cmd);
void   *mrsas_alloc_frame(struct mrsas_softc *sc, struct mrsas_mfi_cmd *cmd);
static int mrsas_create_frame_pool(struct mrsas_softc *sc);
static void
mrsas_alloc_cb(void *arg, bus_dma_segment_t *segs,
    int nsegs, int error);

extern struct mrsas_mfi_cmd *mrsas_get_mfi_cmd(struct mrsas_softc *sc);
extern void mrsas_release_mfi_cmd(struct mrsas_mfi_cmd *cmd);
extern int
mrsas_issue_blocked_cmd(struct mrsas_softc *sc,
    struct mrsas_mfi_cmd *cmd);

/*
 * mrsas_data_load_cb:  Callback entry point
 * input:                               Pointer to command packet as argument
 *                                              Pointer to segment
 *                                              Number of segments Error
 *
 * This is the callback function of the bus dma map load.  It builds the SG
 * list.
 */
static void
mrsas_passthru_load_cb(void *arg, bus_dma_segment_t *segs, int nseg, int error)
{
        struct mrsas_passthru_cmd *cb = (struct mrsas_passthru_cmd *)arg;
        struct mrsas_softc *sc = cb->sc;
        int i = 0;

        if (error) {
                cb->error_code = error;
                if (error == EFBIG) {
                        device_printf(sc->mrsas_dev, "mrsas_passthru_load_cb: "
                            "error=%d EFBIG\n", error);
                        cb->complete = 1;
                        return;
                } else {
                        device_printf(sc->mrsas_dev, "mrsas_passthru_load_cb: "
                            "error=%d UNKNOWN\n", error);
                }
        }
        if (nseg > MAX_IOCTL_SGE) {
                cb->error_code = EFBIG;
                device_printf(sc->mrsas_dev, "mrsas_passthru_load_cb: "
                    "too many segments: %d\n", nseg);
                cb->complete = 1;
                return;
        }

        for (i = 0; i < nseg; i++) {
                cb->kern_sge[i].phys_addr = htole64(segs[i].ds_addr);
                cb->kern_sge[i].length = htole32(segs[i].ds_len);
        }
        cb->sge_count = nseg;

        bus_dmamap_sync(cb->ioctl_data_tag, cb->ioctl_data_dmamap,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

        cb->complete = 1;
}

/*
 * mrsas_passthru:      Handle pass-through commands
 * input:                       Adapter instance soft state argument pointer
 *
 * This function is called from mrsas_ioctl() to handle pass-through and ioctl
 * commands to Firmware.
 */
int
mrsas_passthru(struct mrsas_softc *sc, void *arg, u_long ioctlCmd)
{
        struct mrsas_iocpacket *user_ioc = (struct mrsas_iocpacket *)arg;

#ifdef COMPAT_FREEBSD32
        struct mrsas_iocpacket32 *user_ioc32 = (struct mrsas_iocpacket32 *)arg;

#endif
        union mrsas_frame *in_cmd = (union mrsas_frame *)&(user_ioc->frame.raw);
        struct mrsas_mfi_cmd *cmd = NULL;
        bus_dma_tag_t ioctl_data_tag[MAX_IOCTL_SGE];
        bus_dmamap_t ioctl_data_dmamap[MAX_IOCTL_SGE];
        void *ioctl_data_mem[MAX_IOCTL_SGE];
        bus_addr_t ioctl_data_phys_addr[MAX_IOCTL_SGE];
        bus_dma_tag_t ioctl_sense_tag = 0;
        bus_dmamap_t ioctl_sense_dmamap = 0;
        void *ioctl_sense_mem = NULL;
        bus_addr_t ioctl_sense_phys_addr = 0;
        int i, ioctl_data_size = 0, ioctl_sense_size, ret = 0;
        struct mrsas_sge32 *kern_sge32;
        unsigned long *sense_ptr;
        uint8_t *iov_base_ptrin = NULL;
        size_t iov_len = 0;

        /*
         * Check for NOP from MegaCli... MegaCli can issue a DCMD of 0.  In
         * this case do nothing and return 0 to it as status.
         */
        if (in_cmd->dcmd.opcode == 0) {
                device_printf(sc->mrsas_dev, "In %s() Got a NOP\n", __func__);
                user_ioc->frame.hdr.cmd_status = MFI_STAT_OK;
                return (0);
        }
        /* Validate SGL length */
        if (user_ioc->sge_count > MAX_IOCTL_SGE) {
                device_printf(sc->mrsas_dev, "In %s() SGL is too long (%d > 8).\n",
                    __func__, user_ioc->sge_count);
                return (ENOENT);
        }
        /* Get a command */
        cmd = mrsas_get_mfi_cmd(sc);
        if (!cmd) {
                device_printf(sc->mrsas_dev, "Failed to get a free cmd for IOCTL\n");
                return (ENOMEM);
        }
        /*
         * User's IOCTL packet has 2 frames (maximum). Copy those two frames
         * into our cmd's frames. cmd->frame's context will get overwritten
         * when we copy from user's frames. So set that value alone
         * separately
         */
        memcpy(cmd->frame, user_ioc->frame.raw, 2 * MEGAMFI_FRAME_SIZE);
        cmd->frame->hdr.context = cmd->index;
        cmd->frame->hdr.pad_0 = 0;
        cmd->frame->hdr.flags &= ~(MFI_FRAME_IEEE | MFI_FRAME_SGL64 |
            MFI_FRAME_SENSE64);

        /*
         * The management interface between applications and the fw uses MFI
         * frames. E.g, RAID configuration changes, LD property changes etc
         * are accomplishes through different kinds of MFI frames. The driver
         * needs to care only about substituting user buffers with kernel
         * buffers in SGLs. The location of SGL is embedded in the struct
         * iocpacket itself.
         */
        kern_sge32 = (struct mrsas_sge32 *)
            ((uintptr_t)cmd->frame + user_ioc->sgl_off);

        memset(ioctl_data_tag, 0, (sizeof(bus_dma_tag_t) * MAX_IOCTL_SGE));
        memset(ioctl_data_dmamap, 0, (sizeof(bus_dmamap_t) * MAX_IOCTL_SGE));
        memset(ioctl_data_mem, 0, (sizeof(void *) * MAX_IOCTL_SGE));
        memset(ioctl_data_phys_addr, 0, (sizeof(bus_addr_t) * MAX_IOCTL_SGE));

        /*
         * For each user buffer, create a mirror buffer and copy in
         */
        for (i = 0; i < user_ioc->sge_count; i++) {
                if (ioctlCmd == MRSAS_IOC_FIRMWARE_PASS_THROUGH64) {
                        if (!user_ioc->sgl[i].iov_len)
                                continue;
                        ioctl_data_size = user_ioc->sgl[i].iov_len;
#ifdef COMPAT_FREEBSD32
                } else {
                        if (!user_ioc32->sgl[i].iov_len)
                                continue;
                        ioctl_data_size = user_ioc32->sgl[i].iov_len;
#endif
                }
                if (bus_dma_tag_create(sc->mrsas_parent_tag,
                    1, 0,
                    BUS_SPACE_MAXADDR_32BIT,
                    BUS_SPACE_MAXADDR,
                    NULL, NULL,
                    ioctl_data_size,
                    1,
                    ioctl_data_size,
                    BUS_DMA_ALLOCNOW,
                    NULL, NULL,
                    &ioctl_data_tag[i])) {
                        device_printf(sc->mrsas_dev, "Cannot allocate ioctl data tag\n");
                        ret = ENOMEM;
                        goto out;
                }
                if (bus_dmamem_alloc(ioctl_data_tag[i], (void **)&ioctl_data_mem[i],
                    (BUS_DMA_NOWAIT | BUS_DMA_ZERO), &ioctl_data_dmamap[i])) {
                        device_printf(sc->mrsas_dev, "Cannot allocate ioctl data mem\n");
                        ret = ENOMEM;
                        goto out;
                }
                if (bus_dmamap_load(ioctl_data_tag[i], ioctl_data_dmamap[i],
                    ioctl_data_mem[i], ioctl_data_size, mrsas_alloc_cb,
                    &ioctl_data_phys_addr[i], BUS_DMA_NOWAIT)) {
                        device_printf(sc->mrsas_dev, "Cannot load ioctl data mem\n");
                        ret = ENOMEM;
                        goto out;
                }
                /* Save the physical address and length */
                kern_sge32[i].phys_addr = (u_int32_t)ioctl_data_phys_addr[i];

                if (ioctlCmd == MRSAS_IOC_FIRMWARE_PASS_THROUGH64) {
                        kern_sge32[i].length = user_ioc->sgl[i].iov_len;

                        iov_base_ptrin = user_ioc->sgl[i].iov_base;
                        iov_len = user_ioc->sgl[i].iov_len;
#ifdef COMPAT_FREEBSD32
                } else {
                        kern_sge32[i].length = user_ioc32->sgl[i].iov_len;

                        iov_base_ptrin = PTRIN(user_ioc32->sgl[i].iov_base);
                        iov_len = user_ioc32->sgl[i].iov_len;
#endif
                }

                /* Copy in data from user space */
                ret = copyin(iov_base_ptrin, ioctl_data_mem[i], iov_len);
                if (ret) {
                        device_printf(sc->mrsas_dev, "IOCTL copyin failed!\n");
                        goto out;
                }
        }

        ioctl_sense_size = user_ioc->sense_len;

        if (user_ioc->sense_len) {
                if (bus_dma_tag_create(sc->mrsas_parent_tag,
                    1, 0,
                    BUS_SPACE_MAXADDR_32BIT,
                    BUS_SPACE_MAXADDR,
                    NULL, NULL,
                    ioctl_sense_size,
                    1,
                    ioctl_sense_size,
                    BUS_DMA_ALLOCNOW,
                    NULL, NULL,
                    &ioctl_sense_tag)) {
                        device_printf(sc->mrsas_dev, "Cannot allocate ioctl sense tag\n");
                        ret = ENOMEM;
                        goto out;
                }
                if (bus_dmamem_alloc(ioctl_sense_tag, (void **)&ioctl_sense_mem,
                    (BUS_DMA_NOWAIT | BUS_DMA_ZERO), &ioctl_sense_dmamap)) {
                        device_printf(sc->mrsas_dev, "Cannot allocate ioctl sense mem\n");
                        ret = ENOMEM;
                        goto out;
                }
                if (bus_dmamap_load(ioctl_sense_tag, ioctl_sense_dmamap,
                    ioctl_sense_mem, ioctl_sense_size, mrsas_alloc_cb,
                    &ioctl_sense_phys_addr, BUS_DMA_NOWAIT)) {
                        device_printf(sc->mrsas_dev, "Cannot load ioctl sense mem\n");
                        ret = ENOMEM;
                        goto out;
                }
                sense_ptr =
                    (unsigned long *)((uintptr_t)cmd->frame + user_ioc->sense_off);
                *sense_ptr = ioctl_sense_phys_addr;
        }
        /*
         * Set the sync_cmd flag so that the ISR knows not to complete this
         * cmd to the SCSI mid-layer
         */
        cmd->sync_cmd = 1;
        ret = mrsas_issue_blocked_cmd(sc, cmd);
        if (ret == ETIMEDOUT) {
                mrsas_dprint(sc, MRSAS_OCR,
                    "IOCTL command is timed out, initiating OCR\n");
                sc->do_timedout_reset = MFI_DCMD_TIMEOUT_OCR;
                ret = EAGAIN;
                goto out;
        }
        cmd->sync_cmd = 0;

        /*
         * copy out the kernel buffers to user buffers
         */
        for (i = 0; i < user_ioc->sge_count; i++) {
                if (ioctlCmd == MRSAS_IOC_FIRMWARE_PASS_THROUGH64) {
                        iov_base_ptrin = user_ioc->sgl[i].iov_base;
                        iov_len = user_ioc->sgl[i].iov_len;
#ifdef COMPAT_FREEBSD32
                } else {
                        iov_base_ptrin = PTRIN(user_ioc32->sgl[i].iov_base);
                        iov_len = user_ioc32->sgl[i].iov_len;
#endif
                }

                ret = copyout(ioctl_data_mem[i], iov_base_ptrin, iov_len);
                if (ret) {
                        device_printf(sc->mrsas_dev, "IOCTL copyout failed!\n");
                        goto out;
                }
        }

        /*
         * copy out the sense
         */
        if (user_ioc->sense_len) {
                /*
                 * sense_buff points to the location that has the user sense
                 * buffer address
                 */
                sense_ptr = (unsigned long *)((uintptr_t)user_ioc->frame.raw +
                    user_ioc->sense_off);
                ret = copyout(ioctl_sense_mem, (unsigned long *)(uintptr_t)*sense_ptr,
                    user_ioc->sense_len);
                if (ret) {
                        device_printf(sc->mrsas_dev, "IOCTL sense copyout failed!\n");
                        goto out;
                }
        }
        /*
         * Return command status to user space
         */
        memcpy(&user_ioc->frame.hdr.cmd_status, &cmd->frame->hdr.cmd_status,
            sizeof(u_int8_t));

out:
        /*
         * Release sense buffer
         */
        if (user_ioc->sense_len) {
                if (ioctl_sense_phys_addr)
                        bus_dmamap_unload(ioctl_sense_tag, ioctl_sense_dmamap);
                if (ioctl_sense_mem != NULL)
                        bus_dmamem_free(ioctl_sense_tag, ioctl_sense_mem, ioctl_sense_dmamap);
                if (ioctl_sense_tag != NULL)
                        bus_dma_tag_destroy(ioctl_sense_tag);
        }
        /*
         * Release data buffers
         */
        for (i = 0; i < user_ioc->sge_count; i++) {
                if (ioctlCmd == MRSAS_IOC_FIRMWARE_PASS_THROUGH64) {
                        if (!user_ioc->sgl[i].iov_len)
                                continue;
#ifdef COMPAT_FREEBSD32
                } else {
                        if (!user_ioc32->sgl[i].iov_len)
                                continue;
#endif
                }
                if (ioctl_data_phys_addr[i])
                        bus_dmamap_unload(ioctl_data_tag[i], ioctl_data_dmamap[i]);
                if (ioctl_data_mem[i] != NULL)
                        bus_dmamem_free(ioctl_data_tag[i], ioctl_data_mem[i],
                            ioctl_data_dmamap[i]);
                if (ioctl_data_tag[i] != NULL)
                        bus_dma_tag_destroy(ioctl_data_tag[i]);
        }
        /* Free command */
        mrsas_release_mfi_cmd(cmd);

        return (ret);
}

/**
 * mrsas_user_command:    Handle user mode DCMD and buffer
 * input:                 Adapter instance soft state
 *                        argument pointer
 *
 * This function is called from mrsas_ioctl() DCMDs to firmware for mfiutil
 */
int
mrsas_user_command(struct mrsas_softc *sc, struct mfi_ioc_passthru *ioc)
{
        struct mrsas_mfi_cmd *cmd;
        struct mrsas_dcmd_frame *dcmd;
        struct mrsas_passthru_cmd *passcmd;
        bus_dma_tag_t ioctl_data_tag;
        bus_dmamap_t ioctl_data_dmamap;
        bus_addr_t ioctl_data_phys_addr;
        struct mrsas_sge64 *kern_sge;
        int ret, ioctl_data_size;
        char *ioctl_temp_data_mem;

        ret = 0;
        ioctl_temp_data_mem = NULL;
        passcmd = NULL;
        ioctl_data_phys_addr = 0;
        dcmd = NULL;
        cmd = NULL;
        ioctl_data_tag = NULL;
        ioctl_data_dmamap = NULL;
        ioctl_data_dmamap = NULL;

        /* Get a command */
        cmd = mrsas_get_mfi_cmd(sc);
        if (!cmd) {
                device_printf(sc->mrsas_dev,
                    "Failed to get a free cmd for IOCTL\n");
                return(ENOMEM);
        }

        /*
         * Frame is DCMD
         */
        dcmd = (struct mrsas_dcmd_frame *)cmd->frame;
        memcpy(dcmd, &ioc->ioc_frame, sizeof(struct mrsas_dcmd_frame));

        ioctl_data_size = ioc->buf_size;

        cmd->frame->hdr.context = cmd->index;
        cmd->frame->hdr.pad_0 = 0;
        cmd->frame->hdr.flags = MFI_FRAME_DIR_BOTH;
        if (sizeof(bus_addr_t) == 8)
                cmd->frame->hdr.flags |= MFI_FRAME_SGL64 | MFI_FRAME_SENSE64;

        kern_sge = (struct mrsas_sge64 *)(&dcmd->sgl);

        if (ioctl_data_size == 0) {
                kern_sge[0].phys_addr = 0;
                kern_sge[0].length = 0;
        } else {
                ioctl_temp_data_mem = malloc(ioc->buf_size, M_MRSAS, M_WAITOK);

                /* Copy in data from user space */
                ret = copyin(ioc->buf, ioctl_temp_data_mem, ioc->buf_size);
                if (ret) {
                        device_printf(sc->mrsas_dev, "IOCTL copyin failed!\n");
                        goto out;
                }

                /*
                 * Allocate a temporary struct to hold parameters for the
                 * callback
                 */
                passcmd = malloc(sizeof(struct mrsas_passthru_cmd), M_MRSAS,
                    M_WAITOK);
                passcmd->complete = 0;
                passcmd->sc = sc;
                passcmd->cmd = cmd;
                passcmd->kern_sge = kern_sge;

                /*
                 * Create a dma tag for passthru buffers
                 */
                if (bus_dma_tag_create(sc->mrsas_parent_tag,   /* parent */
                    1, 0,                   /* algnmnt, boundary */
                    BUS_SPACE_MAXADDR,      /* lowaddr */
                    BUS_SPACE_MAXADDR,      /* highaddr */
                    NULL, NULL,             /* filter, filterarg */
                    ioctl_data_size,        /* maxsize */
                    MAX_IOCTL_SGE,          /* msegments */
                    ioctl_data_size,        /* maxsegsize */
                    BUS_DMA_ALLOCNOW,       /* flags */
                    busdma_lock_mutex,      /* lockfunc */
                    &sc->ioctl_lock,        /* lockarg */
                    &ioctl_data_tag)) {
                        device_printf(sc->mrsas_dev,
                           "Cannot allocate ioctl data tag %d\n",
                            ioc->buf_size);
                        ret = ENOMEM;
                        goto out;
                }

                /* Create memmap */
                if (bus_dmamap_create(ioctl_data_tag, 0, &ioctl_data_dmamap)) {
                        device_printf(sc->mrsas_dev, "Cannot create ioctl "
                            "passthru dmamap\n");
                        ret = ENOMEM;
                        goto out;
                }

                passcmd->ioctl_data_tag = ioctl_data_tag;
                passcmd->ioctl_data_dmamap = ioctl_data_dmamap;

                /* Map data buffer into bus space */
                if (bus_dmamap_load(ioctl_data_tag, ioctl_data_dmamap,
                    ioctl_temp_data_mem, ioc->buf_size, mrsas_passthru_load_cb,
                    passcmd, BUS_DMA_NOWAIT)) {
                        device_printf(sc->mrsas_dev, "Cannot load ioctl "
                            "passthru data mem%s %d\n", curproc->p_comm, ioctl_data_size);
                        ret = ENOMEM;
                        goto out;
                }

                while (passcmd->complete == 0) {
                        pause("mrsas_passthru", hz);
                }

                cmd->frame->dcmd.sge_count = passcmd->sge_count;
        }

        /*
         * Set the sync_cmd flag so that the ISR knows not to complete this
         * cmd to the SCSI mid-layer
         */
        cmd->sync_cmd = 1;
        mrsas_issue_blocked_cmd(sc, cmd);
        cmd->sync_cmd = 0;

        if (ioctl_data_size != 0) {
                bus_dmamap_sync(ioctl_data_tag, ioctl_data_dmamap,
                    BUS_DMASYNC_POSTREAD);
                /*
                 * copy out the kernel buffers to user buffers
                 */
                ret = copyout(ioctl_temp_data_mem, ioc->buf, ioc->buf_size);
                if (ret) {
                        device_printf(sc->mrsas_dev,
                            "IOCTL copyout failed!\n");
                        goto out;
                }
        }

        /*
         * Return command status to user space
         */
        memcpy(&ioc->ioc_frame.cmd_status, &cmd->frame->hdr.cmd_status,
            sizeof(u_int8_t));

out:
        /*
         * Release temporary passthrough ioctl
         */
        if (ioctl_temp_data_mem)
                free(ioctl_temp_data_mem, M_MRSAS);
        if (passcmd)
                free(passcmd, M_MRSAS);

        /*
         * Release data buffers
         */
        if (ioctl_data_phys_addr) {
                bus_dmamap_unload(ioctl_data_tag, ioctl_data_dmamap);
                bus_dmamap_destroy(ioctl_data_tag, ioctl_data_dmamap);
        }
        if (ioctl_data_tag != NULL)
                bus_dma_tag_destroy(ioctl_data_tag);
        /* Free command */
        mrsas_release_mfi_cmd(cmd);

        return(ret);
}


/*
 * mrsas_alloc_mfi_cmds:        Allocates the command packets
 * input:                                       Adapter instance soft state
 *
 * Each IOCTL or passthru command that is issued to the FW are wrapped in a
 * local data structure called mrsas_mfi_cmd.  The frame embedded in this
 * mrsas_mfi is issued to FW. The array is used only to look up the
 * mrsas_mfi_cmd given the context. The free commands are maintained in a
 * linked list.
 */
int
mrsas_alloc_mfi_cmds(struct mrsas_softc *sc)
{
        int i, j;
        u_int32_t max_cmd;
        struct mrsas_mfi_cmd *cmd;

        max_cmd = MRSAS_MAX_MFI_CMDS;

        /*
         * sc->mfi_cmd_list is an array of struct mrsas_mfi_cmd pointers.
         * Allocate the dynamic array first and then allocate individual
         * commands.
         */
        sc->mfi_cmd_list = malloc(sizeof(struct mrsas_mfi_cmd *) * max_cmd, M_MRSAS, M_NOWAIT);
        if (!sc->mfi_cmd_list) {
                device_printf(sc->mrsas_dev, "Cannot alloc memory for mfi_cmd cmd_list.\n");
                return (ENOMEM);
        }
        memset(sc->mfi_cmd_list, 0, sizeof(struct mrsas_mfi_cmd *) * max_cmd);
        for (i = 0; i < max_cmd; i++) {
                sc->mfi_cmd_list[i] = malloc(sizeof(struct mrsas_mfi_cmd),
                    M_MRSAS, M_NOWAIT);
                if (!sc->mfi_cmd_list[i]) {
                        for (j = 0; j < i; j++)
                                free(sc->mfi_cmd_list[j], M_MRSAS);
                        free(sc->mfi_cmd_list, M_MRSAS);
                        sc->mfi_cmd_list = NULL;
                        return (ENOMEM);
                }
        }

        for (i = 0; i < max_cmd; i++) {
                cmd = sc->mfi_cmd_list[i];
                memset(cmd, 0, sizeof(struct mrsas_mfi_cmd));
                cmd->index = i;
                cmd->ccb_ptr = NULL;
                cmd->sc = sc;
                TAILQ_INSERT_TAIL(&(sc->mrsas_mfi_cmd_list_head), cmd, next);
        }

        /* create a frame pool and assign one frame to each command */
        if (mrsas_create_frame_pool(sc)) {
                device_printf(sc->mrsas_dev, "Cannot allocate DMA frame pool.\n");
                /* Free the frames */
                for (i = 0; i < MRSAS_MAX_MFI_CMDS; i++) {
                        cmd = sc->mfi_cmd_list[i];
                        mrsas_free_frame(sc, cmd);
                }
                if (sc->mficmd_frame_tag != NULL)
                        bus_dma_tag_destroy(sc->mficmd_frame_tag);
                return (ENOMEM);
        }
        return (0);
}

/*
 * mrsas_create_frame_pool:     Creates DMA pool for cmd frames
 * input:                                       Adapter soft state
 *
 * Each command packet has an embedded DMA memory buffer that is used for
 * filling MFI frame and the SG list that immediately follows the frame. This
 * function creates those DMA memory buffers for each command packet by using
 * PCI pool facility. pad_0 is initialized to 0 to prevent corrupting value
 * of context and could cause FW crash.
 */
static int
mrsas_create_frame_pool(struct mrsas_softc *sc)
{
        int i;
        struct mrsas_mfi_cmd *cmd;

        if (bus_dma_tag_create(sc->mrsas_parent_tag,
            1, 0,
            BUS_SPACE_MAXADDR_32BIT,
            BUS_SPACE_MAXADDR,
            NULL, NULL,
            MRSAS_MFI_FRAME_SIZE,
            1,
            MRSAS_MFI_FRAME_SIZE,
            BUS_DMA_ALLOCNOW,
            NULL, NULL,
            &sc->mficmd_frame_tag)) {
                device_printf(sc->mrsas_dev, "Cannot create MFI frame tag\n");
                return (ENOMEM);
        }
        for (i = 0; i < MRSAS_MAX_MFI_CMDS; i++) {
                cmd = sc->mfi_cmd_list[i];
                cmd->frame = mrsas_alloc_frame(sc, cmd);
                if (cmd->frame == NULL) {
                        device_printf(sc->mrsas_dev, "Cannot alloc MFI frame memory\n");
                        return (ENOMEM);
                }
                /*
                 * For MFI controllers.
                 * max_num_sge = 60
                 * max_sge_sz  = 16 byte (sizeof megasas_sge_skinny)
                 * Totl 960 byte (15 MFI frame of 64 byte)
                 *
                 * Fusion adapter require only 3 extra frame.
                 * max_num_sge = 16 (defined as MAX_IOCTL_SGE)
                 * max_sge_sz  = 12 byte (sizeof  megasas_sge64)
                 * Total 192 byte (3 MFI frame of 64 byte)
                 */
                memset(cmd->frame, 0, MRSAS_MFI_FRAME_SIZE);
                cmd->frame->io.context = cmd->index;
                cmd->frame->io.pad_0 = 0;
        }

        return (0);
}

/*
 * mrsas_alloc_frame:   Allocates MFI Frames
 * input:                               Adapter soft state
 *
 * Create bus DMA memory tag and dmamap and load memory for MFI frames. Returns
 * virtual memory pointer to allocated region.
 */
void   *
mrsas_alloc_frame(struct mrsas_softc *sc, struct mrsas_mfi_cmd *cmd)
{
        u_int32_t frame_size = MRSAS_MFI_FRAME_SIZE;

        if (bus_dmamem_alloc(sc->mficmd_frame_tag, (void **)&cmd->frame_mem,
            BUS_DMA_NOWAIT, &cmd->frame_dmamap)) {
                device_printf(sc->mrsas_dev, "Cannot alloc MFI frame memory\n");
                return (NULL);
        }
        if (bus_dmamap_load(sc->mficmd_frame_tag, cmd->frame_dmamap,
            cmd->frame_mem, frame_size, mrsas_alloc_cb,
            &cmd->frame_phys_addr, BUS_DMA_NOWAIT)) {
                device_printf(sc->mrsas_dev, "Cannot load IO request memory\n");
                return (NULL);
        }
        return (cmd->frame_mem);
}

/*
 * mrsas_alloc_cb:      Callback function of bus_dmamap_load()
 * input:                       callback argument,
 *                                      machine dependent type that describes DMA segments,
 *                                      number of segments,
 *                                      error code.
 *
 * This function is for the driver to receive mapping information resultant of
 * the bus_dmamap_load(). The information is actually not being used, but the
 * address is saved anyway.
 */
static void
mrsas_alloc_cb(void *arg, bus_dma_segment_t *segs,
    int nsegs, int error)
{
        bus_addr_t *addr;

        addr = arg;
        *addr = segs[0].ds_addr;
}

/*
 * mrsas_free_frames:   Frees memory for  MFI frames
 * input:                               Adapter soft state
 *
 * Deallocates MFI frames memory.  Called from mrsas_free_mem() during detach
 * and error case during creation of frame pool.
 */
void
mrsas_free_frame(struct mrsas_softc *sc, struct mrsas_mfi_cmd *cmd)
{
        if (cmd->frame_phys_addr)
                bus_dmamap_unload(sc->mficmd_frame_tag, cmd->frame_dmamap);
        if (cmd->frame_mem != NULL)
                bus_dmamem_free(sc->mficmd_frame_tag, cmd->frame_mem, cmd->frame_dmamap);
}