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Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-dma-contig.c')
-rw-r--r--drivers/media/common/videobuf2/videobuf2-dma-contig.c865
1 files changed, 865 insertions, 0 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
new file mode 100644
index 0000000000..2fa455d4a0
--- /dev/null
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -0,0 +1,865 @@
+/*
+ * videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <pawel@osciak.com>
+ *
+ * This program 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.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/module.h>
+#include <linux/refcount.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include <linux/highmem.h>
+
+#include <media/videobuf2-v4l2.h>
+#include <media/videobuf2-dma-contig.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_dc_buf {
+ struct device *dev;
+ void *vaddr;
+ unsigned long size;
+ void *cookie;
+ dma_addr_t dma_addr;
+ unsigned long attrs;
+ enum dma_data_direction dma_dir;
+ struct sg_table *dma_sgt;
+ struct frame_vector *vec;
+
+ /* MMAP related */
+ struct vb2_vmarea_handler handler;
+ refcount_t refcount;
+ struct sg_table *sgt_base;
+
+ /* DMABUF related */
+ struct dma_buf_attachment *db_attach;
+
+ struct vb2_buffer *vb;
+ bool non_coherent_mem;
+};
+
+/*********************************************/
+/* scatterlist table functions */
+/*********************************************/
+
+static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt)
+{
+ struct scatterlist *s;
+ dma_addr_t expected = sg_dma_address(sgt->sgl);
+ unsigned int i;
+ unsigned long size = 0;
+
+ for_each_sgtable_dma_sg(sgt, s, i) {
+ if (sg_dma_address(s) != expected)
+ break;
+ expected += sg_dma_len(s);
+ size += sg_dma_len(s);
+ }
+ return size;
+}
+
+/*********************************************/
+/* callbacks for all buffers */
+/*********************************************/
+
+static void *vb2_dc_cookie(struct vb2_buffer *vb, void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return &buf->dma_addr;
+}
+
+/*
+ * This function may fail if:
+ *
+ * - dma_buf_vmap() fails
+ * E.g. due to lack of virtual mapping address space, or due to
+ * dmabuf->ops misconfiguration.
+ *
+ * - dma_vmap_noncontiguous() fails
+ * For instance, when requested buffer size is larger than totalram_pages().
+ * Relevant for buffers that use non-coherent memory.
+ *
+ * - Queue DMA attrs have DMA_ATTR_NO_KERNEL_MAPPING set
+ * Relevant for buffers that use coherent memory.
+ */
+static void *vb2_dc_vaddr(struct vb2_buffer *vb, void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (buf->vaddr)
+ return buf->vaddr;
+
+ if (buf->db_attach) {
+ struct iosys_map map;
+
+ if (!dma_buf_vmap_unlocked(buf->db_attach->dmabuf, &map))
+ buf->vaddr = map.vaddr;
+
+ return buf->vaddr;
+ }
+
+ if (buf->non_coherent_mem)
+ buf->vaddr = dma_vmap_noncontiguous(buf->dev, buf->size,
+ buf->dma_sgt);
+ return buf->vaddr;
+}
+
+static unsigned int vb2_dc_num_users(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return refcount_read(&buf->refcount);
+}
+
+static void vb2_dc_prepare(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ struct sg_table *sgt = buf->dma_sgt;
+
+ /* This takes care of DMABUF and user-enforced cache sync hint */
+ if (buf->vb->skip_cache_sync_on_prepare)
+ return;
+
+ if (!buf->non_coherent_mem)
+ return;
+
+ /* Non-coherent MMAP only */
+ if (buf->vaddr)
+ flush_kernel_vmap_range(buf->vaddr, buf->size);
+
+ /* For both USERPTR and non-coherent MMAP */
+ dma_sync_sgtable_for_device(buf->dev, sgt, buf->dma_dir);
+}
+
+static void vb2_dc_finish(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ struct sg_table *sgt = buf->dma_sgt;
+
+ /* This takes care of DMABUF and user-enforced cache sync hint */
+ if (buf->vb->skip_cache_sync_on_finish)
+ return;
+
+ if (!buf->non_coherent_mem)
+ return;
+
+ /* Non-coherent MMAP only */
+ if (buf->vaddr)
+ invalidate_kernel_vmap_range(buf->vaddr, buf->size);
+
+ /* For both USERPTR and non-coherent MMAP */
+ dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir);
+}
+
+/*********************************************/
+/* callbacks for MMAP buffers */
+/*********************************************/
+
+static void vb2_dc_put(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (!refcount_dec_and_test(&buf->refcount))
+ return;
+
+ if (buf->non_coherent_mem) {
+ if (buf->vaddr)
+ dma_vunmap_noncontiguous(buf->dev, buf->vaddr);
+ dma_free_noncontiguous(buf->dev, buf->size,
+ buf->dma_sgt, buf->dma_dir);
+ } else {
+ if (buf->sgt_base) {
+ sg_free_table(buf->sgt_base);
+ kfree(buf->sgt_base);
+ }
+ dma_free_attrs(buf->dev, buf->size, buf->cookie,
+ buf->dma_addr, buf->attrs);
+ }
+ put_device(buf->dev);
+ kfree(buf);
+}
+
+static int vb2_dc_alloc_coherent(struct vb2_dc_buf *buf)
+{
+ struct vb2_queue *q = buf->vb->vb2_queue;
+
+ buf->cookie = dma_alloc_attrs(buf->dev,
+ buf->size,
+ &buf->dma_addr,
+ GFP_KERNEL | q->gfp_flags,
+ buf->attrs);
+ if (!buf->cookie)
+ return -ENOMEM;
+
+ if (q->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING)
+ return 0;
+
+ buf->vaddr = buf->cookie;
+ return 0;
+}
+
+static int vb2_dc_alloc_non_coherent(struct vb2_dc_buf *buf)
+{
+ struct vb2_queue *q = buf->vb->vb2_queue;
+
+ buf->dma_sgt = dma_alloc_noncontiguous(buf->dev,
+ buf->size,
+ buf->dma_dir,
+ GFP_KERNEL | q->gfp_flags,
+ buf->attrs);
+ if (!buf->dma_sgt)
+ return -ENOMEM;
+
+ buf->dma_addr = sg_dma_address(buf->dma_sgt->sgl);
+
+ /*
+ * For non-coherent buffers the kernel mapping is created on demand
+ * in vb2_dc_vaddr().
+ */
+ return 0;
+}
+
+static void *vb2_dc_alloc(struct vb2_buffer *vb,
+ struct device *dev,
+ unsigned long size)
+{
+ struct vb2_dc_buf *buf;
+ int ret;
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->attrs = vb->vb2_queue->dma_attrs;
+ buf->dma_dir = vb->vb2_queue->dma_dir;
+ buf->vb = vb;
+ buf->non_coherent_mem = vb->vb2_queue->non_coherent_mem;
+
+ buf->size = size;
+ /* Prevent the device from being released while the buffer is used */
+ buf->dev = get_device(dev);
+
+ if (buf->non_coherent_mem)
+ ret = vb2_dc_alloc_non_coherent(buf);
+ else
+ ret = vb2_dc_alloc_coherent(buf);
+
+ if (ret) {
+ dev_err(dev, "dma alloc of size %lu failed\n", size);
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_dc_put;
+ buf->handler.arg = buf;
+
+ refcount_set(&buf->refcount, 1);
+
+ return buf;
+}
+
+static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ int ret;
+
+ if (!buf) {
+ printk(KERN_ERR "No buffer to map\n");
+ return -EINVAL;
+ }
+
+ if (buf->non_coherent_mem)
+ ret = dma_mmap_noncontiguous(buf->dev, vma, buf->size,
+ buf->dma_sgt);
+ else
+ ret = dma_mmap_attrs(buf->dev, vma, buf->cookie, buf->dma_addr,
+ buf->size, buf->attrs);
+ if (ret) {
+ pr_err("Remapping memory failed, error: %d\n", ret);
+ return ret;
+ }
+
+ vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
+ vma->vm_private_data = &buf->handler;
+ vma->vm_ops = &vb2_common_vm_ops;
+
+ vma->vm_ops->open(vma);
+
+ pr_debug("%s: mapped dma addr 0x%08lx at 0x%08lx, size %lu\n",
+ __func__, (unsigned long)buf->dma_addr, vma->vm_start,
+ buf->size);
+
+ return 0;
+}
+
+/*********************************************/
+/* DMABUF ops for exporters */
+/*********************************************/
+
+struct vb2_dc_attachment {
+ struct sg_table sgt;
+ enum dma_data_direction dma_dir;
+};
+
+static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf,
+ struct dma_buf_attachment *dbuf_attach)
+{
+ struct vb2_dc_attachment *attach;
+ unsigned int i;
+ struct scatterlist *rd, *wr;
+ struct sg_table *sgt;
+ struct vb2_dc_buf *buf = dbuf->priv;
+ int ret;
+
+ attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+ if (!attach)
+ return -ENOMEM;
+
+ sgt = &attach->sgt;
+ /* Copy the buf->base_sgt scatter list to the attachment, as we can't
+ * map the same scatter list to multiple attachments at the same time.
+ */
+ ret = sg_alloc_table(sgt, buf->sgt_base->orig_nents, GFP_KERNEL);
+ if (ret) {
+ kfree(attach);
+ return -ENOMEM;
+ }
+
+ rd = buf->sgt_base->sgl;
+ wr = sgt->sgl;
+ for (i = 0; i < sgt->orig_nents; ++i) {
+ sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
+ rd = sg_next(rd);
+ wr = sg_next(wr);
+ }
+
+ attach->dma_dir = DMA_NONE;
+ dbuf_attach->priv = attach;
+
+ return 0;
+}
+
+static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf,
+ struct dma_buf_attachment *db_attach)
+{
+ struct vb2_dc_attachment *attach = db_attach->priv;
+ struct sg_table *sgt;
+
+ if (!attach)
+ return;
+
+ sgt = &attach->sgt;
+
+ /* release the scatterlist cache */
+ if (attach->dma_dir != DMA_NONE)
+ /*
+ * Cache sync can be skipped here, as the vb2_dc memory is
+ * allocated from device coherent memory, which means the
+ * memory locations do not require any explicit cache
+ * maintenance prior or after being used by the device.
+ */
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ sg_free_table(sgt);
+ kfree(attach);
+ db_attach->priv = NULL;
+}
+
+static struct sg_table *vb2_dc_dmabuf_ops_map(
+ struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
+{
+ struct vb2_dc_attachment *attach = db_attach->priv;
+ struct sg_table *sgt;
+
+ sgt = &attach->sgt;
+ /* return previously mapped sg table */
+ if (attach->dma_dir == dma_dir)
+ return sgt;
+
+ /* release any previous cache */
+ if (attach->dma_dir != DMA_NONE) {
+ dma_unmap_sgtable(db_attach->dev, sgt, attach->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ attach->dma_dir = DMA_NONE;
+ }
+
+ /*
+ * mapping to the client with new direction, no cache sync
+ * required see comment in vb2_dc_dmabuf_ops_detach()
+ */
+ if (dma_map_sgtable(db_attach->dev, sgt, dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC)) {
+ pr_err("failed to map scatterlist\n");
+ return ERR_PTR(-EIO);
+ }
+
+ attach->dma_dir = dma_dir;
+
+ return sgt;
+}
+
+static void vb2_dc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+ struct sg_table *sgt, enum dma_data_direction dma_dir)
+{
+ /* nothing to be done here */
+}
+
+static void vb2_dc_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+ /* drop reference obtained in vb2_dc_get_dmabuf */
+ vb2_dc_put(dbuf->priv);
+}
+
+static int
+vb2_dc_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
+ enum dma_data_direction direction)
+{
+ return 0;
+}
+
+static int
+vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
+ enum dma_data_direction direction)
+{
+ return 0;
+}
+
+static int vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct iosys_map *map)
+{
+ struct vb2_dc_buf *buf;
+ void *vaddr;
+
+ buf = dbuf->priv;
+ vaddr = vb2_dc_vaddr(buf->vb, buf);
+ if (!vaddr)
+ return -EINVAL;
+
+ iosys_map_set_vaddr(map, vaddr);
+
+ return 0;
+}
+
+static int vb2_dc_dmabuf_ops_mmap(struct dma_buf *dbuf,
+ struct vm_area_struct *vma)
+{
+ return vb2_dc_mmap(dbuf->priv, vma);
+}
+
+static const struct dma_buf_ops vb2_dc_dmabuf_ops = {
+ .attach = vb2_dc_dmabuf_ops_attach,
+ .detach = vb2_dc_dmabuf_ops_detach,
+ .map_dma_buf = vb2_dc_dmabuf_ops_map,
+ .unmap_dma_buf = vb2_dc_dmabuf_ops_unmap,
+ .begin_cpu_access = vb2_dc_dmabuf_ops_begin_cpu_access,
+ .end_cpu_access = vb2_dc_dmabuf_ops_end_cpu_access,
+ .vmap = vb2_dc_dmabuf_ops_vmap,
+ .mmap = vb2_dc_dmabuf_ops_mmap,
+ .release = vb2_dc_dmabuf_ops_release,
+};
+
+static struct sg_table *vb2_dc_get_base_sgt(struct vb2_dc_buf *buf)
+{
+ int ret;
+ struct sg_table *sgt;
+
+ if (buf->non_coherent_mem)
+ return buf->dma_sgt;
+
+ sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt) {
+ dev_err(buf->dev, "failed to alloc sg table\n");
+ return NULL;
+ }
+
+ ret = dma_get_sgtable_attrs(buf->dev, sgt, buf->cookie, buf->dma_addr,
+ buf->size, buf->attrs);
+ if (ret < 0) {
+ dev_err(buf->dev, "failed to get scatterlist from DMA API\n");
+ kfree(sgt);
+ return NULL;
+ }
+
+ return sgt;
+}
+
+static struct dma_buf *vb2_dc_get_dmabuf(struct vb2_buffer *vb,
+ void *buf_priv,
+ unsigned long flags)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ struct dma_buf *dbuf;
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+ exp_info.ops = &vb2_dc_dmabuf_ops;
+ exp_info.size = buf->size;
+ exp_info.flags = flags;
+ exp_info.priv = buf;
+
+ if (!buf->sgt_base)
+ buf->sgt_base = vb2_dc_get_base_sgt(buf);
+
+ if (WARN_ON(!buf->sgt_base))
+ return NULL;
+
+ dbuf = dma_buf_export(&exp_info);
+ if (IS_ERR(dbuf))
+ return NULL;
+
+ /* dmabuf keeps reference to vb2 buffer */
+ refcount_inc(&buf->refcount);
+
+ return dbuf;
+}
+
+/*********************************************/
+/* callbacks for USERPTR buffers */
+/*********************************************/
+
+static void vb2_dc_put_userptr(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ struct sg_table *sgt = buf->dma_sgt;
+ int i;
+ struct page **pages;
+
+ if (sgt) {
+ /*
+ * No need to sync to CPU, it's already synced to the CPU
+ * since the finish() memop will have been called before this.
+ */
+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC);
+ pages = frame_vector_pages(buf->vec);
+ /* sgt should exist only if vector contains pages... */
+ BUG_ON(IS_ERR(pages));
+ if (buf->dma_dir == DMA_FROM_DEVICE ||
+ buf->dma_dir == DMA_BIDIRECTIONAL)
+ for (i = 0; i < frame_vector_count(buf->vec); i++)
+ set_page_dirty_lock(pages[i]);
+ sg_free_table(sgt);
+ kfree(sgt);
+ } else {
+ dma_unmap_resource(buf->dev, buf->dma_addr, buf->size,
+ buf->dma_dir, 0);
+ }
+ vb2_destroy_framevec(buf->vec);
+ kfree(buf);
+}
+
+static void *vb2_dc_get_userptr(struct vb2_buffer *vb, struct device *dev,
+ unsigned long vaddr, unsigned long size)
+{
+ struct vb2_dc_buf *buf;
+ struct frame_vector *vec;
+ unsigned int offset;
+ int n_pages, i;
+ int ret = 0;
+ struct sg_table *sgt;
+ unsigned long contig_size;
+ unsigned long dma_align = dma_get_cache_alignment();
+
+ /* Only cache aligned DMA transfers are reliable */
+ if (!IS_ALIGNED(vaddr | size, dma_align)) {
+ pr_debug("user data must be aligned to %lu bytes\n", dma_align);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!size) {
+ pr_debug("size is zero\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->dev = dev;
+ buf->dma_dir = vb->vb2_queue->dma_dir;
+ buf->vb = vb;
+
+ offset = lower_32_bits(offset_in_page(vaddr));
+ vec = vb2_create_framevec(vaddr, size, buf->dma_dir == DMA_FROM_DEVICE ||
+ buf->dma_dir == DMA_BIDIRECTIONAL);
+ if (IS_ERR(vec)) {
+ ret = PTR_ERR(vec);
+ goto fail_buf;
+ }
+ buf->vec = vec;
+ n_pages = frame_vector_count(vec);
+ ret = frame_vector_to_pages(vec);
+ if (ret < 0) {
+ unsigned long *nums = frame_vector_pfns(vec);
+
+ /*
+ * Failed to convert to pages... Check the memory is physically
+ * contiguous and use direct mapping
+ */
+ for (i = 1; i < n_pages; i++)
+ if (nums[i-1] + 1 != nums[i])
+ goto fail_pfnvec;
+ buf->dma_addr = dma_map_resource(buf->dev,
+ __pfn_to_phys(nums[0]), size, buf->dma_dir, 0);
+ if (dma_mapping_error(buf->dev, buf->dma_addr)) {
+ ret = -ENOMEM;
+ goto fail_pfnvec;
+ }
+ goto out;
+ }
+
+ sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt) {
+ pr_err("failed to allocate sg table\n");
+ ret = -ENOMEM;
+ goto fail_pfnvec;
+ }
+
+ ret = sg_alloc_table_from_pages(sgt, frame_vector_pages(vec), n_pages,
+ offset, size, GFP_KERNEL);
+ if (ret) {
+ pr_err("failed to initialize sg table\n");
+ goto fail_sgt;
+ }
+
+ /*
+ * No need to sync to the device, this will happen later when the
+ * prepare() memop is called.
+ */
+ if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir,
+ DMA_ATTR_SKIP_CPU_SYNC)) {
+ pr_err("failed to map scatterlist\n");
+ ret = -EIO;
+ goto fail_sgt_init;
+ }
+
+ contig_size = vb2_dc_get_contiguous_size(sgt);
+ if (contig_size < size) {
+ pr_err("contiguous mapping is too small %lu/%lu\n",
+ contig_size, size);
+ ret = -EFAULT;
+ goto fail_map_sg;
+ }
+
+ buf->dma_addr = sg_dma_address(sgt->sgl);
+ buf->dma_sgt = sgt;
+ buf->non_coherent_mem = 1;
+
+out:
+ buf->size = size;
+
+ return buf;
+
+fail_map_sg:
+ dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC);
+
+fail_sgt_init:
+ sg_free_table(sgt);
+
+fail_sgt:
+ kfree(sgt);
+
+fail_pfnvec:
+ vb2_destroy_framevec(vec);
+
+fail_buf:
+ kfree(buf);
+
+ return ERR_PTR(ret);
+}
+
+/*********************************************/
+/* callbacks for DMABUF buffers */
+/*********************************************/
+
+static int vb2_dc_map_dmabuf(void *mem_priv)
+{
+ struct vb2_dc_buf *buf = mem_priv;
+ struct sg_table *sgt;
+ unsigned long contig_size;
+
+ if (WARN_ON(!buf->db_attach)) {
+ pr_err("trying to pin a non attached buffer\n");
+ return -EINVAL;
+ }
+
+ if (WARN_ON(buf->dma_sgt)) {
+ pr_err("dmabuf buffer is already pinned\n");
+ return 0;
+ }
+
+ /* get the associated scatterlist for this buffer */
+ sgt = dma_buf_map_attachment_unlocked(buf->db_attach, buf->dma_dir);
+ if (IS_ERR(sgt)) {
+ pr_err("Error getting dmabuf scatterlist\n");
+ return -EINVAL;
+ }
+
+ /* checking if dmabuf is big enough to store contiguous chunk */
+ contig_size = vb2_dc_get_contiguous_size(sgt);
+ if (contig_size < buf->size) {
+ pr_err("contiguous chunk is too small %lu/%lu\n",
+ contig_size, buf->size);
+ dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt,
+ buf->dma_dir);
+ return -EFAULT;
+ }
+
+ buf->dma_addr = sg_dma_address(sgt->sgl);
+ buf->dma_sgt = sgt;
+ buf->vaddr = NULL;
+
+ return 0;
+}
+
+static void vb2_dc_unmap_dmabuf(void *mem_priv)
+{
+ struct vb2_dc_buf *buf = mem_priv;
+ struct sg_table *sgt = buf->dma_sgt;
+ struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr);
+
+ if (WARN_ON(!buf->db_attach)) {
+ pr_err("trying to unpin a not attached buffer\n");
+ return;
+ }
+
+ if (WARN_ON(!sgt)) {
+ pr_err("dmabuf buffer is already unpinned\n");
+ return;
+ }
+
+ if (buf->vaddr) {
+ dma_buf_vunmap_unlocked(buf->db_attach->dmabuf, &map);
+ buf->vaddr = NULL;
+ }
+ dma_buf_unmap_attachment_unlocked(buf->db_attach, sgt, buf->dma_dir);
+
+ buf->dma_addr = 0;
+ buf->dma_sgt = NULL;
+}
+
+static void vb2_dc_detach_dmabuf(void *mem_priv)
+{
+ struct vb2_dc_buf *buf = mem_priv;
+
+ /* if vb2 works correctly you should never detach mapped buffer */
+ if (WARN_ON(buf->dma_addr))
+ vb2_dc_unmap_dmabuf(buf);
+
+ /* detach this attachment */
+ dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
+ kfree(buf);
+}
+
+static void *vb2_dc_attach_dmabuf(struct vb2_buffer *vb, struct device *dev,
+ struct dma_buf *dbuf, unsigned long size)
+{
+ struct vb2_dc_buf *buf;
+ struct dma_buf_attachment *dba;
+
+ if (dbuf->size < size)
+ return ERR_PTR(-EFAULT);
+
+ if (WARN_ON(!dev))
+ return ERR_PTR(-EINVAL);
+
+ buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->dev = dev;
+ buf->vb = vb;
+
+ /* create attachment for the dmabuf with the user device */
+ dba = dma_buf_attach(dbuf, buf->dev);
+ if (IS_ERR(dba)) {
+ pr_err("failed to attach dmabuf\n");
+ kfree(buf);
+ return dba;
+ }
+
+ buf->dma_dir = vb->vb2_queue->dma_dir;
+ buf->size = size;
+ buf->db_attach = dba;
+
+ return buf;
+}
+
+/*********************************************/
+/* DMA CONTIG exported functions */
+/*********************************************/
+
+const struct vb2_mem_ops vb2_dma_contig_memops = {
+ .alloc = vb2_dc_alloc,
+ .put = vb2_dc_put,
+ .get_dmabuf = vb2_dc_get_dmabuf,
+ .cookie = vb2_dc_cookie,
+ .vaddr = vb2_dc_vaddr,
+ .mmap = vb2_dc_mmap,
+ .get_userptr = vb2_dc_get_userptr,
+ .put_userptr = vb2_dc_put_userptr,
+ .prepare = vb2_dc_prepare,
+ .finish = vb2_dc_finish,
+ .map_dmabuf = vb2_dc_map_dmabuf,
+ .unmap_dmabuf = vb2_dc_unmap_dmabuf,
+ .attach_dmabuf = vb2_dc_attach_dmabuf,
+ .detach_dmabuf = vb2_dc_detach_dmabuf,
+ .num_users = vb2_dc_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
+
+/**
+ * vb2_dma_contig_set_max_seg_size() - configure DMA max segment size
+ * @dev: device for configuring DMA parameters
+ * @size: size of DMA max segment size to set
+ *
+ * To allow mapping the scatter-list into a single chunk in the DMA
+ * address space, the device is required to have the DMA max segment
+ * size parameter set to a value larger than the buffer size. Otherwise,
+ * the DMA-mapping subsystem will split the mapping into max segment
+ * size chunks. This function sets the DMA max segment size
+ * parameter to let DMA-mapping map a buffer as a single chunk in DMA
+ * address space.
+ * This code assumes that the DMA-mapping subsystem will merge all
+ * scatterlist segments if this is really possible (for example when
+ * an IOMMU is available and enabled).
+ * Ideally, this parameter should be set by the generic bus code, but it
+ * is left with the default 64KiB value due to historical litmiations in
+ * other subsystems (like limited USB host drivers) and there no good
+ * place to set it to the proper value.
+ * This function should be called from the drivers, which are known to
+ * operate on platforms with IOMMU and provide access to shared buffers
+ * (either USERPTR or DMABUF). This should be done before initializing
+ * videobuf2 queue.
+ */
+int vb2_dma_contig_set_max_seg_size(struct device *dev, unsigned int size)
+{
+ if (!dev->dma_parms) {
+ dev_err(dev, "Failed to set max_seg_size: dma_parms is NULL\n");
+ return -ENODEV;
+ }
+ if (dma_get_max_seg_size(dev) < size)
+ return dma_set_max_seg_size(dev, size);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_contig_set_max_seg_size);
+
+MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(DMA_BUF);
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-15 06:27:22 +0000