linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/*

 * Tegra host1x Command DMA

 *

 * Copyright (c) 2010-2013, NVIDIA Corporation.

 */

​

​

#include <asm/cacheflush.h>

#include <linux/device.h>

#include <linux/dma-mapping.h>

#include <linux/host1x.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>

#include <linux/kfifo.h>

#include <linux/slab.h>

#include <trace/events/host1x.h>

​

#include "cdma.h"

#include "channel.h"

#include "dev.h"

#include "debug.h"

#include "job.h"

​

/*

 * push_buffer

 *

 * The push buffer is a circular array of words to be fetched by command DMA.

 * Note that it works slightly differently to the sync queue; fence == pos

 * means that the push buffer is full, not empty.

 */

​

/*

 * Typically the commands written into the push buffer are a pair of words. We

 * use slots to represent each of these pairs and to simplify things. Note the

 * strange number of slots allocated here. 512 slots will fit exactly within a

 * single memory page. We also need one additional word at the end of the push

 * buffer for the RESTART opcode that will instruct the CDMA to jump back to

 * the beginning of the push buffer. With 512 slots, this means that we'll use

 * 2 memory pages and waste 4092 bytes of the second page that will never be

 * used.

 */

#define HOST1X_PUSHBUFFER_SLOTS 511

​

/*

 * Clean up push buffer resources

 */

static void host1x_pushbuffer_destroy(struct push_buffer *pb)

{

    struct host1x_cdma *cdma = pb_to_cdma(pb);

    struct host1x *host1x = cdma_to_host1x(cdma);

​

    if (!pb->mapped)

        return;

​

    if (host1x->domain) {

        iommu_unmap(host1x->domain, pb->dma, pb->alloc_size);

        free_iova(&host1x->iova, iova_pfn(&host1x->iova, pb->dma));

    }

​

    dma_free_wc(host1x->dev, pb->alloc_size, pb->mapped, pb->phys);

​

    pb->mapped = NULL;

    pb->phys = 0;

}

​

/*

 * Init push buffer resources

 */

static int host1x_pushbuffer_init(struct push_buffer *pb)

{

    struct host1x_cdma *cdma = pb_to_cdma(pb);

    struct host1x *host1x = cdma_to_host1x(cdma);

    struct iova *alloc;

    u32 size;

    int err;

​

    pb->mapped = NULL;

    pb->phys = 0;

    pb->size = HOST1X_PUSHBUFFER_SLOTS * 8;

​

    size = pb->size + 4;

​

    /* initialize buffer pointers */

    pb->fence = pb->size - 8;

    pb->pos = 0;

​

    if (host1x->domain) {

        unsigned long shift;

​

        size = iova_align(&host1x->iova, size);

​