Avoid beyond bounds copy while caching ACL

[zen-stable.git] / drivers / staging / crystalhd / crystalhd_misc.c

/***************************************************************************
 *         Copyright (c) 2005-2009, Broadcom Corporation.
 *
 *  Name: crystalhd_misc . c
 *
 *  Description:
 *              BCM70012 Linux driver misc routines.
 *
 *  HISTORY:
 *
 **********************************************************************
 * This file is part of the crystalhd device driver.
 *
 * This driver is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 2 of the License.
 *
 * This driver is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this driver.  If not, see <http://www.gnu.org/licenses/>.
 **********************************************************************/

#include <linux/slab.h>

#include "crystalhd_misc.h"
#include "crystalhd_lnx.h"

uint32_t g_linklog_level;

static inline uint32_t crystalhd_dram_rd(struct crystalhd_adp *adp, uint32_t mem_off)
{
        crystalhd_reg_wr(adp, DCI_DRAM_BASE_ADDR, (mem_off >> 19));
        return bc_dec_reg_rd(adp, (0x00380000 | (mem_off & 0x0007FFFF)));
}

static inline void crystalhd_dram_wr(struct crystalhd_adp *adp, uint32_t mem_off, uint32_t val)
{
        crystalhd_reg_wr(adp, DCI_DRAM_BASE_ADDR, (mem_off >> 19));
        bc_dec_reg_wr(adp, (0x00380000 | (mem_off & 0x0007FFFF)), val);
}

static inline enum BC_STATUS bc_chk_dram_range(struct crystalhd_adp *adp, uint32_t start_off, uint32_t cnt)
{
        return BC_STS_SUCCESS;
}

static struct crystalhd_dio_req *crystalhd_alloc_dio(struct crystalhd_adp *adp)
{
        unsigned long flags = 0;
        struct crystalhd_dio_req *temp = NULL;

        if (!adp) {
                BCMLOG_ERR("Invalid Arg!!\n");
                return temp;
        }

        spin_lock_irqsave(&adp->lock, flags);
        temp = adp->ua_map_free_head;
        if (temp)
                adp->ua_map_free_head = adp->ua_map_free_head->next;
        spin_unlock_irqrestore(&adp->lock, flags);

        return temp;
}

static void crystalhd_free_dio(struct crystalhd_adp *adp, struct crystalhd_dio_req *dio)
{
        unsigned long flags = 0;

        if (!adp || !dio)
                return;
        spin_lock_irqsave(&adp->lock, flags);
        dio->sig = crystalhd_dio_inv;
        dio->page_cnt = 0;
        dio->fb_size = 0;
        memset(&dio->uinfo, 0, sizeof(dio->uinfo));
        dio->next = adp->ua_map_free_head;
        adp->ua_map_free_head = dio;
        spin_unlock_irqrestore(&adp->lock, flags);
}

static struct crystalhd_elem *crystalhd_alloc_elem(struct crystalhd_adp *adp)
{
        unsigned long flags = 0;
        struct crystalhd_elem *temp = NULL;

        if (!adp)
                return temp;
        spin_lock_irqsave(&adp->lock, flags);
        temp = adp->elem_pool_head;
        if (temp) {
                adp->elem_pool_head = adp->elem_pool_head->flink;
                memset(temp, 0, sizeof(*temp));
        }
        spin_unlock_irqrestore(&adp->lock, flags);

        return temp;
}
static void crystalhd_free_elem(struct crystalhd_adp *adp, struct crystalhd_elem *elem)
{
        unsigned long flags = 0;

        if (!adp || !elem)
                return;
        spin_lock_irqsave(&adp->lock, flags);
        elem->flink = adp->elem_pool_head;
        adp->elem_pool_head = elem;
        spin_unlock_irqrestore(&adp->lock, flags);
}

static inline void crystalhd_set_sg(struct scatterlist *sg, struct page *page,
                                  unsigned int len, unsigned int offset)
{
        sg_set_page(sg, page, len, offset);
#ifdef CONFIG_X86_64
        sg->dma_length = len;
#endif
}

static inline void crystalhd_init_sg(struct scatterlist *sg, unsigned int entries)
{
        /* http://lkml.org/lkml/2007/11/27/68 */
        sg_init_table(sg, entries);
}

/*========================== Extern ========================================*/
/**
 * bc_dec_reg_rd - Read 7412's device register.
 * @adp: Adapter instance
 * @reg_off: Register offset.
 *
 * Return:
 *      32bit value read
 *
 * 7412's device register read routine. This interface use
 * 7412's device access range mapped from BAR-2 (4M) of PCIe
 * configuration space.
 */
uint32_t bc_dec_reg_rd(struct crystalhd_adp *adp, uint32_t reg_off)
{
        if (!adp || (reg_off > adp->pci_mem_len)) {
                BCMLOG_ERR("dec_rd_reg_off outof range: 0x%08x\n", reg_off);
                return 0;
        }

        return readl(adp->addr + reg_off);
}

/**
 * bc_dec_reg_wr - Write 7412's device register
 * @adp: Adapter instance
 * @reg_off: Register offset.
 * @val: Dword value to be written.
 *
 * Return:
 *      none.
 *
 * 7412's device register write routine. This interface use
 * 7412's device access range mapped from BAR-2 (4M) of PCIe
 * configuration space.
 */
void bc_dec_reg_wr(struct crystalhd_adp *adp, uint32_t reg_off, uint32_t val)
{
        if (!adp || (reg_off > adp->pci_mem_len)) {
                BCMLOG_ERR("dec_wr_reg_off outof range: 0x%08x\n", reg_off);
                return;
        }
        writel(val, adp->addr + reg_off);
        udelay(8);
}

/**
 * crystalhd_reg_rd - Read Link's device register.
 * @adp: Adapter instance
 * @reg_off: Register offset.
 *
 * Return:
 *      32bit value read
 *
 * Link device register  read routine. This interface use
 * Link's device access range mapped from BAR-1 (64K) of PCIe
 * configuration space.
 *
 */
uint32_t crystalhd_reg_rd(struct crystalhd_adp *adp, uint32_t reg_off)
{
        if (!adp || (reg_off > adp->pci_i2o_len)) {
                BCMLOG_ERR("link_rd_reg_off outof range: 0x%08x\n", reg_off);
                return 0;
        }
        return readl(adp->i2o_addr + reg_off);
}

/**
 * crystalhd_reg_wr - Write Link's device register
 * @adp: Adapter instance
 * @reg_off: Register offset.
 * @val: Dword value to be written.
 *
 * Return:
 *      none.
 *
 * Link device register  write routine. This interface use
 * Link's device access range mapped from BAR-1 (64K) of PCIe
 * configuration space.
 *
 */
void crystalhd_reg_wr(struct crystalhd_adp *adp, uint32_t reg_off, uint32_t val)
{
        if (!adp || (reg_off > adp->pci_i2o_len)) {
                BCMLOG_ERR("link_wr_reg_off outof range: 0x%08x\n", reg_off);
                return;
        }
        writel(val, adp->i2o_addr + reg_off);
}

/**
 * crystalhd_mem_rd - Read data from 7412's DRAM area.
 * @adp: Adapter instance
 * @start_off: Start offset.
 * @dw_cnt: Count in dwords.
 * @rd_buff: Buffer to copy the data from dram.
 *
 * Return:
 *      Status.
 *
 * 7412's Dram read routine.
 */
enum BC_STATUS crystalhd_mem_rd(struct crystalhd_adp *adp, uint32_t start_off,
                         uint32_t dw_cnt, uint32_t *rd_buff)
{
        uint32_t ix = 0;

        if (!adp || !rd_buff ||
            (bc_chk_dram_range(adp, start_off, dw_cnt) != BC_STS_SUCCESS)) {
                BCMLOG_ERR("Invalid arg\n");
                return BC_STS_INV_ARG;
        }
        for (ix = 0; ix < dw_cnt; ix++)
                rd_buff[ix] = crystalhd_dram_rd(adp, (start_off + (ix * 4)));

        return BC_STS_SUCCESS;
}

/**
 * crystalhd_mem_wr - Write data to 7412's DRAM area.
 * @adp: Adapter instance
 * @start_off: Start offset.
 * @dw_cnt: Count in dwords.
 * @wr_buff: Data Buffer to be written.
 *
 * Return:
 *      Status.
 *
 * 7412's Dram write routine.
 */
enum BC_STATUS crystalhd_mem_wr(struct crystalhd_adp *adp, uint32_t start_off,
                         uint32_t dw_cnt, uint32_t *wr_buff)
{
        uint32_t ix = 0;

        if (!adp || !wr_buff ||
            (bc_chk_dram_range(adp, start_off, dw_cnt) != BC_STS_SUCCESS)) {
                BCMLOG_ERR("Invalid arg\n");
                return BC_STS_INV_ARG;
        }

        for (ix = 0; ix < dw_cnt; ix++)
                crystalhd_dram_wr(adp, (start_off + (ix * 4)), wr_buff[ix]);

        return BC_STS_SUCCESS;
}
/**
 * crystalhd_pci_cfg_rd - PCIe config read
 * @adp: Adapter instance
 * @off: PCI config space offset.
 * @len: Size -- Byte, Word & dword.
 * @val: Value read
 *
 * Return:
 *      Status.
 *
 * Get value from Link's PCIe config space.
 */
enum BC_STATUS crystalhd_pci_cfg_rd(struct crystalhd_adp *adp, uint32_t off,
                             uint32_t len, uint32_t *val)
{
        enum BC_STATUS sts = BC_STS_SUCCESS;
        int rc = 0;

        if (!adp || !val) {
                BCMLOG_ERR("Invalid arg\n");
                return BC_STS_INV_ARG;
        }

        switch (len) {
        case 1:
                rc = pci_read_config_byte(adp->pdev, off, (u8 *)val);
                break;
        case 2:
                rc = pci_read_config_word(adp->pdev, off, (u16 *)val);
                break;
        case 4:
                rc = pci_read_config_dword(adp->pdev, off, (u32 *)val);
                break;
        default:
                rc = -EINVAL;
                sts = BC_STS_INV_ARG;
                BCMLOG_ERR("Invalid len:%d\n", len);
        }

        if (rc && (sts == BC_STS_SUCCESS))
                sts = BC_STS_ERROR;

        return sts;
}

/**
 * crystalhd_pci_cfg_wr - PCIe config write
 * @adp: Adapter instance
 * @off: PCI config space offset.
 * @len: Size -- Byte, Word & dword.
 * @val: Value to be written
 *
 * Return:
 *      Status.
 *
 * Set value to Link's PCIe config space.
 */
enum BC_STATUS crystalhd_pci_cfg_wr(struct crystalhd_adp *adp, uint32_t off,
                             uint32_t len, uint32_t val)
{
        enum BC_STATUS sts = BC_STS_SUCCESS;
        int rc = 0;

        if (!adp || !val) {
                BCMLOG_ERR("Invalid arg\n");
                return BC_STS_INV_ARG;
        }

        switch (len) {
        case 1:
                rc = pci_write_config_byte(adp->pdev, off, (u8)val);
                break;
        case 2:
                rc = pci_write_config_word(adp->pdev, off, (u16)val);
                break;
        case 4:
                rc = pci_write_config_dword(adp->pdev, off, val);
                break;
        default:
                rc = -EINVAL;
                sts = BC_STS_INV_ARG;
                BCMLOG_ERR("Invalid len:%d\n", len);
        }

        if (rc && (sts == BC_STS_SUCCESS))
                sts = BC_STS_ERROR;

        return sts;
}

/**
 * bc_kern_dma_alloc - Allocate memory for Dma rings
 * @adp: Adapter instance
 * @sz: Size of the memory to allocate.
 * @phy_addr: Physical address of the memory allocated.
 *         Typedef to system's dma_addr_t (u64)
 *
 * Return:
 *  Pointer to allocated memory..
 *
 * Wrapper to Linux kernel interface.
 *
 */
void *bc_kern_dma_alloc(struct crystalhd_adp *adp, uint32_t sz,
                        dma_addr_t *phy_addr)
{
        void *temp = NULL;

        if (!adp || !sz || !phy_addr) {
                BCMLOG_ERR("Invalide Arg..\n");
                return temp;
        }

        temp = pci_alloc_consistent(adp->pdev, sz, phy_addr);
        if (temp)
                memset(temp, 0, sz);

        return temp;
}

/**
 * bc_kern_dma_free - Release Dma ring memory.
 * @adp: Adapter instance
 * @sz: Size of the memory to allocate.
 * @ka: Kernel virtual address returned during _dio_alloc()
 * @phy_addr: Physical address of the memory allocated.
 *         Typedef to system's dma_addr_t (u64)
 *
 * Return:
 *     none.
 */
void bc_kern_dma_free(struct crystalhd_adp *adp, uint32_t sz, void *ka,
                      dma_addr_t phy_addr)
{
        if (!adp || !ka || !sz || !phy_addr) {
                BCMLOG_ERR("Invalide Arg..\n");
                return;
        }

        pci_free_consistent(adp->pdev, sz, ka, phy_addr);
}

/**
 * crystalhd_create_dioq - Create Generic DIO queue
 * @adp: Adapter instance
 * @dioq_hnd: Handle to the dio queue created
 * @cb  : Optional - Call back To free the element.
 * @cbctx: Context to pass to callback.
 *
 * Return:
 *  status
 *
 * Initialize Generic DIO queue to hold any data. Callback
 * will be used to free elements while deleting the queue.
 */
enum BC_STATUS crystalhd_create_dioq(struct crystalhd_adp *adp,
                              struct crystalhd_dioq **dioq_hnd,
                              crystalhd_data_free_cb cb, void *cbctx)
{
        struct crystalhd_dioq *dioq = NULL;

        if (!adp || !dioq_hnd) {
                BCMLOG_ERR("Invalid arg!!\n");
                return BC_STS_INV_ARG;
        }

        dioq = kzalloc(sizeof(*dioq), GFP_KERNEL);
        if (!dioq)
                return BC_STS_INSUFF_RES;

        spin_lock_init(&dioq->lock);
        dioq->sig = BC_LINK_DIOQ_SIG;
        dioq->head = (struct crystalhd_elem *)&dioq->head;
        dioq->tail = (struct crystalhd_elem *)&dioq->head;
        crystalhd_create_event(&dioq->event);
        dioq->adp = adp;
        dioq->data_rel_cb = cb;
        dioq->cb_context = cbctx;
        *dioq_hnd = dioq;

        return BC_STS_SUCCESS;
}

/**
 * crystalhd_delete_dioq - Delete Generic DIO queue
 * @adp: Adapter instance
 * @dioq: DIOQ instance..
 *
 * Return:
 *  None.
 *
 * Release Generic DIO queue. This function will remove
 * all the entries from the Queue and will release data
 * by calling the call back provided during creation.
 *
 */
void crystalhd_delete_dioq(struct crystalhd_adp *adp, struct crystalhd_dioq *dioq)
{
        void *temp;

        if (!dioq || (dioq->sig != BC_LINK_DIOQ_SIG))
                return;

        do {
                temp = crystalhd_dioq_fetch(dioq);
                if (temp && dioq->data_rel_cb)
                        dioq->data_rel_cb(dioq->cb_context, temp);
        } while (temp);
        dioq->sig = 0;
        kfree(dioq);
}

/**
 * crystalhd_dioq_add - Add new DIO request element.
 * @ioq: DIO queue instance
 * @t: DIO request to be added.
 * @wake: True - Wake up suspended process.
 * @tag: Special tag to assign - For search and get.
 *
 * Return:
 *  Status.
 *
 * Insert new element to Q tail.
 */
enum BC_STATUS crystalhd_dioq_add(struct crystalhd_dioq *ioq, void *data,
                           bool wake, uint32_t tag)
{
        unsigned long flags = 0;
        struct crystalhd_elem *tmp;

        if (!ioq || (ioq->sig != BC_LINK_DIOQ_SIG) || !data) {
                BCMLOG_ERR("Invalid arg!!\n");
                return BC_STS_INV_ARG;
        }

        tmp = crystalhd_alloc_elem(ioq->adp);
        if (!tmp) {
                BCMLOG_ERR("No free elements.\n");
                return BC_STS_INSUFF_RES;
        }

        tmp->data = data;
        tmp->tag = tag;
        spin_lock_irqsave(&ioq->lock, flags);
        tmp->flink = (struct crystalhd_elem *)&ioq->head;
        tmp->blink = ioq->tail;
        tmp->flink->blink = tmp;
        tmp->blink->flink = tmp;
        ioq->count++;
        spin_unlock_irqrestore(&ioq->lock, flags);

        if (wake)
                crystalhd_set_event(&ioq->event);

        return BC_STS_SUCCESS;
}

/**
 * crystalhd_dioq_fetch - Fetch element from head.
 * @ioq: DIO queue instance
 *
 * Return:
 *      data element from the head..
 *
 * Remove an element from Queue.
 */
void *crystalhd_dioq_fetch(struct crystalhd_dioq *ioq)
{
        unsigned long flags = 0;
        struct crystalhd_elem *tmp;
        struct crystalhd_elem *ret = NULL;
        void *data = NULL;

        if (!ioq || (ioq->sig != BC_LINK_DIOQ_SIG)) {
                BCMLOG_ERR("Invalid arg!!\n");
                return data;
        }

        spin_lock_irqsave(&ioq->lock, flags);
        tmp = ioq->head;
        if (tmp != (struct crystalhd_elem *)&ioq->head) {
                ret = tmp;
                tmp->flink->blink = tmp->blink;
                tmp->blink->flink = tmp->flink;
                ioq->count--;
        }
        spin_unlock_irqrestore(&ioq->lock, flags);
        if (ret) {
                data = ret->data;
                crystalhd_free_elem(ioq->adp, ret);
        }

        return data;
}
/**
 * crystalhd_dioq_find_and_fetch - Search the tag and Fetch element
 * @ioq: DIO queue instance
 * @tag: Tag to search for.
 *
 * Return:
 *      element from the head..
 *
 * Search TAG and remove the element.
 */
void *crystalhd_dioq_find_and_fetch(struct crystalhd_dioq *ioq, uint32_t tag)
{
        unsigned long flags = 0;
        struct crystalhd_elem *tmp;
        struct crystalhd_elem *ret = NULL;
        void *data = NULL;

        if (!ioq || (ioq->sig != BC_LINK_DIOQ_SIG)) {
                BCMLOG_ERR("Invalid arg!!\n");
                return data;
        }

        spin_lock_irqsave(&ioq->lock, flags);
        tmp = ioq->head;
        while (tmp != (struct crystalhd_elem *)&ioq->head) {
                if (tmp->tag == tag) {
                        ret = tmp;
                        tmp->flink->blink = tmp->blink;
                        tmp->blink->flink = tmp->flink;
                        ioq->count--;
                        break;
                }
                tmp = tmp->flink;
        }
        spin_unlock_irqrestore(&ioq->lock, flags);

        if (ret) {
                data = ret->data;
                crystalhd_free_elem(ioq->adp, ret);
        }

        return data;
}

/**
 * crystalhd_dioq_fetch_wait - Fetch element from Head.
 * @ioq: DIO queue instance
 * @to_secs: Wait timeout in seconds..
 *
 * Return:
 *      element from the head..
 *
 * Return element from head if Q is not empty. Wait for new element
 * if Q is empty for Timeout seconds.
 */
void *crystalhd_dioq_fetch_wait(struct crystalhd_dioq *ioq, uint32_t to_secs,
                              uint32_t *sig_pend)
{
        unsigned long flags = 0;
        int rc = 0, count;
        void *tmp = NULL;

        if (!ioq || (ioq->sig != BC_LINK_DIOQ_SIG) || !to_secs || !sig_pend) {
                BCMLOG_ERR("Invalid arg!!\n");
                return tmp;
        }

        count = to_secs;
        spin_lock_irqsave(&ioq->lock, flags);
        while ((ioq->count == 0) && count) {
                spin_unlock_irqrestore(&ioq->lock, flags);

                crystalhd_wait_on_event(&ioq->event, (ioq->count > 0), 1000, rc, 0);
                if (rc == 0) {
                        goto out;
                } else if (rc == -EINTR) {
                        BCMLOG(BCMLOG_INFO, "Cancelling fetch wait\n");
                        *sig_pend = 1;
                        return tmp;
                }
                spin_lock_irqsave(&ioq->lock, flags);
                count--;
        }
        spin_unlock_irqrestore(&ioq->lock, flags);

out:
        return crystalhd_dioq_fetch(ioq);
}

/**
 * crystalhd_map_dio - Map user address for DMA
 * @adp:        Adapter instance
 * @ubuff:      User buffer to map.
 * @ubuff_sz:   User buffer size.
 * @uv_offset:  UV buffer offset.
 * @en_422mode: TRUE:422 FALSE:420 Capture mode.
 * @dir_tx:     TRUE for Tx (To device from host)
 * @dio_hnd:    Handle to mapped DIO request.
 *
 * Return:
 *      Status.
 *
 * This routine maps user address and lock pages for DMA.
 *
 */
enum BC_STATUS crystalhd_map_dio(struct crystalhd_adp *adp, void *ubuff,
                          uint32_t ubuff_sz, uint32_t uv_offset,
                          bool en_422mode, bool dir_tx,
                          struct crystalhd_dio_req **dio_hnd)
{
        struct crystalhd_dio_req        *dio;
        /* FIXME: jarod: should some of these unsigned longs be uint32_t or uintptr_t? */
        unsigned long start = 0, end = 0, uaddr = 0, count = 0;
        unsigned long spsz = 0, uv_start = 0;
        int i = 0, rw = 0, res = 0, nr_pages = 0, skip_fb_sg = 0;

        if (!adp || !ubuff || !ubuff_sz || !dio_hnd) {
                BCMLOG_ERR("Invalid arg\n");
                return BC_STS_INV_ARG;
        }
        /* Compute pages */
        uaddr = (unsigned long)ubuff;
        count = (unsigned long)ubuff_sz;
        end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
        start = uaddr >> PAGE_SHIFT;
        nr_pages = end - start;

        if (!count || ((uaddr + count) < uaddr)) {
                BCMLOG_ERR("User addr overflow!!\n");
                return BC_STS_INV_ARG;
        }

        dio = crystalhd_alloc_dio(adp);
        if (!dio) {
                BCMLOG_ERR("dio pool empty..\n");
                return BC_STS_INSUFF_RES;
        }

        if (dir_tx) {
                rw = WRITE;
                dio->direction = DMA_TO_DEVICE;
        } else {
                rw = READ;
                dio->direction = DMA_FROM_DEVICE;
        }

        if (nr_pages > dio->max_pages) {
                BCMLOG_ERR("max_pages(%d) exceeded(%d)!!\n",
                           dio->max_pages, nr_pages);
                crystalhd_unmap_dio(adp, dio);
                return BC_STS_INSUFF_RES;
        }

        if (uv_offset) {
                uv_start = (uaddr + (unsigned long)uv_offset)  >> PAGE_SHIFT;
                dio->uinfo.uv_sg_ix = uv_start - start;
                dio->uinfo.uv_sg_off = ((uaddr + (unsigned long)uv_offset) & ~PAGE_MASK);
        }

        dio->fb_size = ubuff_sz & 0x03;
        if (dio->fb_size) {
                res = copy_from_user(dio->fb_va,
                                     (void *)(uaddr + count - dio->fb_size),
                                     dio->fb_size);
                if (res) {
                        BCMLOG_ERR("failed %d to copy %u fill bytes from %p\n",
                                   res, dio->fb_size,
                                   (void *)(uaddr + count-dio->fb_size));
                        crystalhd_unmap_dio(adp, dio);
                        return BC_STS_INSUFF_RES;
                }
        }

        down_read(&current->mm->mmap_sem);
        res = get_user_pages(current, current->mm, uaddr, nr_pages, rw == READ,
                             0, dio->pages, NULL);
        up_read(&current->mm->mmap_sem);

        /* Save for release..*/
        dio->sig = crystalhd_dio_locked;
        if (res < nr_pages) {
                BCMLOG_ERR("get pages failed: %d-%d\n", nr_pages, res);
                dio->page_cnt = res;
                crystalhd_unmap_dio(adp, dio);
                return BC_STS_ERROR;
        }

        dio->page_cnt = nr_pages;
        /* Get scatter/gather */
        crystalhd_init_sg(dio->sg, dio->page_cnt);
        crystalhd_set_sg(&dio->sg[0], dio->pages[0], 0, uaddr & ~PAGE_MASK);
        if (nr_pages > 1) {
                dio->sg[0].length = PAGE_SIZE - dio->sg[0].offset;

#ifdef CONFIG_X86_64
                dio->sg[0].dma_length = dio->sg[0].length;
#endif
                count -= dio->sg[0].length;
                for (i = 1; i < nr_pages; i++) {
                        if (count < 4) {
                                spsz = count;
                                skip_fb_sg = 1;
                        } else {
                                spsz = (count < PAGE_SIZE) ?
                                        (count & ~0x03) : PAGE_SIZE;
                        }
                        crystalhd_set_sg(&dio->sg[i], dio->pages[i], spsz, 0);
                        count -= spsz;
                }
        } else {
                if (count < 4) {
                        dio->sg[0].length = count;
                        skip_fb_sg = 1;
                } else {
                        dio->sg[0].length = count - dio->fb_size;
                }
#ifdef CONFIG_X86_64
                dio->sg[0].dma_length = dio->sg[0].length;
#endif
        }
        dio->sg_cnt = pci_map_sg(adp->pdev, dio->sg,
                                 dio->page_cnt, dio->direction);
        if (dio->sg_cnt <= 0) {
                BCMLOG_ERR("sg map %d-%d\n", dio->sg_cnt, dio->page_cnt);
                crystalhd_unmap_dio(adp, dio);
                return BC_STS_ERROR;
        }
        if (dio->sg_cnt && skip_fb_sg)
                dio->sg_cnt -= 1;
        dio->sig = crystalhd_dio_sg_mapped;
        /* Fill in User info.. */
        dio->uinfo.xfr_len   = ubuff_sz;
        dio->uinfo.xfr_buff  = ubuff;
        dio->uinfo.uv_offset = uv_offset;
        dio->uinfo.b422mode  = en_422mode;
        dio->uinfo.dir_tx    = dir_tx;

        *dio_hnd = dio;

        return BC_STS_SUCCESS;
}

/**
 * crystalhd_unmap_sgl - Release mapped resources
 * @adp: Adapter instance
 * @dio: DIO request instance
 *
 * Return:
 *      Status.
 *
 * This routine is to unmap the user buffer pages.
 */
enum BC_STATUS crystalhd_unmap_dio(struct crystalhd_adp *adp, struct crystalhd_dio_req *dio)
{
        struct page *page = NULL;
        int j = 0;

        if (!adp || !dio) {
                BCMLOG_ERR("Invalid arg\n");
                return BC_STS_INV_ARG;
        }

        if ((dio->page_cnt > 0) && (dio->sig != crystalhd_dio_inv)) {
                for (j = 0; j < dio->page_cnt; j++) {
                        page = dio->pages[j];
                        if (page) {
                                if (!PageReserved(page) &&
                                    (dio->direction == DMA_FROM_DEVICE))
                                        SetPageDirty(page);
                                page_cache_release(page);
                        }
                }
        }
        if (dio->sig == crystalhd_dio_sg_mapped)
                pci_unmap_sg(adp->pdev, dio->sg, dio->page_cnt, dio->direction);

        crystalhd_free_dio(adp, dio);

        return BC_STS_SUCCESS;
}

/**
 * crystalhd_create_dio_pool - Allocate mem pool for DIO management.
 * @adp: Adapter instance
 * @max_pages: Max pages for size calculation.
 *
 * Return:
 *      system error.
 *
 * This routine creates a memory pool to hold dio context for
 * for HW Direct IO operation.
 */
int crystalhd_create_dio_pool(struct crystalhd_adp *adp, uint32_t max_pages)
{
        uint32_t asz = 0, i = 0;
        uint8_t *temp;
        struct crystalhd_dio_req *dio;

        if (!adp || !max_pages) {
                BCMLOG_ERR("Invalid Arg!!\n");
                return -EINVAL;
        }

        /* Get dma memory for fill byte handling..*/
        adp->fill_byte_pool = pci_pool_create("crystalhd_fbyte",
                                              adp->pdev, 8, 8, 0);
        if (!adp->fill_byte_pool) {
                BCMLOG_ERR("failed to create fill byte pool\n");
                return -ENOMEM;
        }

        /* Get the max size from user based on 420/422 modes */
        asz =  (sizeof(*dio->pages) * max_pages) +
               (sizeof(*dio->sg) * max_pages) + sizeof(*dio);

        BCMLOG(BCMLOG_DBG, "Initializing Dio pool %d %d %x %p\n",
               BC_LINK_SG_POOL_SZ, max_pages, asz, adp->fill_byte_pool);

        for (i = 0; i < BC_LINK_SG_POOL_SZ; i++) {
                temp = kzalloc(asz, GFP_KERNEL);
                if ((temp) == NULL) {
                        BCMLOG_ERR("Failed to alloc %d mem\n", asz);
                        return -ENOMEM;
                }

                dio = (struct crystalhd_dio_req *)temp;
                temp += sizeof(*dio);
                dio->pages = (struct page **)temp;
                temp += (sizeof(*dio->pages) * max_pages);
                dio->sg = (struct scatterlist *)temp;
                dio->max_pages = max_pages;
                dio->fb_va = pci_pool_alloc(adp->fill_byte_pool, GFP_KERNEL,
                                            &dio->fb_pa);
                if (!dio->fb_va) {
                        BCMLOG_ERR("fill byte alloc failed.\n");
                        return -ENOMEM;
                }

                crystalhd_free_dio(adp, dio);
        }

        return 0;
}

/**
 * crystalhd_destroy_dio_pool - Release DIO mem pool.
 * @adp: Adapter instance
 *
 * Return:
 *      none.
 *
 * This routine releases dio memory pool during close.
 */
void crystalhd_destroy_dio_pool(struct crystalhd_adp *adp)
{
        struct crystalhd_dio_req *dio;
        int count = 0;

        if (!adp) {
                BCMLOG_ERR("Invalid Arg!!\n");
                return;
        }

        do {
                dio = crystalhd_alloc_dio(adp);
                if (dio) {
                        if (dio->fb_va)
                                pci_pool_free(adp->fill_byte_pool,
                                              dio->fb_va, dio->fb_pa);
                        count++;
                        kfree(dio);
                }
        } while (dio);

        if (adp->fill_byte_pool) {
                pci_pool_destroy(adp->fill_byte_pool);
                adp->fill_byte_pool = NULL;
        }

        BCMLOG(BCMLOG_DBG, "Released dio pool %d\n", count);
}

/**
 * crystalhd_create_elem_pool - List element pool creation.
 * @adp: Adapter instance
 * @pool_size: Number of elements in the pool.
 *
 * Return:
 *      0 - success, <0 error
 *
 * Create general purpose list element pool to hold pending,
 * and active requests.
 */
int __devinit crystalhd_create_elem_pool(struct crystalhd_adp *adp,
                uint32_t pool_size)
{
        uint32_t i;
        struct crystalhd_elem *temp;

        if (!adp || !pool_size)
                return -EINVAL;

        for (i = 0; i < pool_size; i++) {
                temp = kzalloc(sizeof(*temp), GFP_KERNEL);
                if (!temp) {
                        BCMLOG_ERR("kalloc failed\n");
                        return -ENOMEM;
                }
                crystalhd_free_elem(adp, temp);
        }
        BCMLOG(BCMLOG_DBG, "allocated %d elem\n", pool_size);
        return 0;
}

/**
 * crystalhd_delete_elem_pool - List element pool deletion.
 * @adp: Adapter instance
 *
 * Return:
 *      none
 *
 * Delete general purpose list element pool.
 */
void crystalhd_delete_elem_pool(struct crystalhd_adp *adp)
{
        struct crystalhd_elem *temp;
        int dbg_cnt = 0;

        if (!adp)
                return;

        do {
                temp = crystalhd_alloc_elem(adp);
                if (temp) {
                        kfree(temp);
                        dbg_cnt++;
                }
        } while (temp);

        BCMLOG(BCMLOG_DBG, "released %d elem\n", dbg_cnt);
}

/*================ Debug support routines.. ================================*/
void crystalhd_show_buffer(uint32_t off, uint8_t *buff, uint32_t dwcount)
{
        uint32_t i, k = 1;

        for (i = 0; i < dwcount; i++) {
                if (k == 1)
                        BCMLOG(BCMLOG_DATA, "0x%08X : ", off);

                BCMLOG(BCMLOG_DATA, " 0x%08X ", *((uint32_t *)buff));

                buff += sizeof(uint32_t);
                off  += sizeof(uint32_t);
                k++;
                if ((i == dwcount - 1) || (k > 4)) {
                        BCMLOG(BCMLOG_DATA, "\n");
                        k = 1;
                }
        }
}