linux-imx

/*

 * A fairly generic DMA-API to IOMMU-API glue layer.

 *

 * Copyright (C) 2014-2015 ARM Ltd.

 *

 * based in part on arch/arm/mm/dma-mapping.c:

 * Copyright (C) 2000-2004 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 *

 * This program 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 program.  If not, see <http://www.gnu.org/licenses/>.

 */

​

#include <linux/acpi_iort.h>

#include <linux/device.h>

#include <linux/dma-iommu.h>

#include <linux/gfp.h>

#include <linux/huge_mm.h>

#include <linux/iommu.h>

#include <linux/iova.h>

#include <linux/irq.h>

#include <linux/mm.h>

#include <linux/pci.h>

#include <linux/scatterlist.h>

#include <linux/vmalloc.h>

​

struct iommu_dma_msi_page {

    struct list_head    list;

    dma_addr_t      iova;

    phys_addr_t     phys;

};

​

enum iommu_dma_cookie_type {

    IOMMU_DMA_IOVA_COOKIE,

    IOMMU_DMA_MSI_COOKIE,

};

​

struct iommu_dma_cookie {

    enum iommu_dma_cookie_type  type;

    union {

        /* Full allocator for IOMMU_DMA_IOVA_COOKIE */

        struct iova_domain  iovad;

        /* Trivial linear page allocator for IOMMU_DMA_MSI_COOKIE */

        dma_addr_t      msi_iova;

    };

    struct list_head        msi_page_list;

    spinlock_t          msi_lock;

​

    /* Domain for flush queue callback; NULL if flush queue not in use */

    struct iommu_domain     *fq_domain;

};

​

static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)

{

    if (cookie->type == IOMMU_DMA_IOVA_COOKIE)

        return cookie->iovad.granule;

    return PAGE_SIZE;

}

​

static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)

{

    struct iommu_dma_cookie *cookie;

​

    cookie = kzalloc(sizeof(*cookie), GFP_KERNEL);

    if (cookie) {

        spin_lock_init(&cookie->msi_lock);

        INIT_LIST_HEAD(&cookie->msi_page_list);

        cookie->type = type;

    }

    return cookie;

}

​

int iommu_dma_init(void)

{

    return iova_cache_get();

}

​

/**

 * iommu_get_dma_cookie - Acquire DMA-API resources for a domain

 * @domain: IOMMU domain to prepare for DMA-API usage

 *

 * IOMMU drivers should normally call this from their domain_alloc

 * callback when domain->type == IOMMU_DOMAIN_DMA.

 */