@@ -80,7 +80,15 @@ vimc-capture:
Module options
--------------
-Vimc has a module parameter to configure the driver.
+Vimc has module parameters to configure the driver.
+
+* ``allocator=<unsigned int>``
+
+ memory allocator selection, default is 0. It specifies the way buffers
+ will be allocated.
+
+ - 0: vmalloc
+ - 1: dma-contig
* ``sca_mult=<unsigned int>``
@@ -7,6 +7,7 @@
#include <media/v4l2-ioctl.h>
#include <media/videobuf2-core.h>
+#include <media/videobuf2-dma-contig.h>
#include <media/videobuf2-vmalloc.h>
#include "vimc-common.h"
@@ -423,14 +424,18 @@ static struct vimc_ent_device *vimc_cap_add(struct vimc_device *vimc,
/* Initialize the vb2 queue */
q = &vcap->queue;
q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
- q->io_modes = VB2_MMAP | VB2_DMABUF | VB2_USERPTR;
+ q->io_modes = VB2_MMAP | VB2_DMABUF;
+ if (vimc_allocator == VIMC_ALLOCATOR_VMALLOC)
+ q->io_modes |= VB2_USERPTR;
q->drv_priv = vcap;
q->buf_struct_size = sizeof(struct vimc_cap_buffer);
q->ops = &vimc_cap_qops;
- q->mem_ops = &vb2_vmalloc_memops;
+ q->mem_ops = vimc_allocator == VIMC_ALLOCATOR_DMA_CONTIG
+ ? &vb2_dma_contig_memops : &vb2_vmalloc_memops;
q->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
q->min_buffers_needed = 2;
q->lock = &vcap->lock;
+ q->dev = v4l2_dev->dev;
ret = vb2_queue_init(q);
if (ret) {
@@ -35,6 +35,13 @@
#define VIMC_PIX_FMT_MAX_CODES 8
+extern unsigned int vimc_allocator;
+
+enum vimc_allocator_type {
+ VIMC_ALLOCATOR_VMALLOC = 0,
+ VIMC_ALLOCATOR_DMA_CONTIG = 1,
+};
+
/**
* vimc_colorimetry_clamp - Adjust colorimetry parameters
*
@@ -5,6 +5,7 @@
* Copyright (C) 2015-2017 Helen Koike <helen.fornazier@gmail.com>
*/
+#include <linux/dma-mapping.h>
#include <linux/font.h>
#include <linux/init.h>
#include <linux/module.h>
@@ -15,6 +16,12 @@
#include "vimc-common.h"
+unsigned int vimc_allocator;
+module_param_named(allocator, vimc_allocator, uint, 0444);
+MODULE_PARM_DESC(allocator, " memory allocator selection, default is 0.\n"
+ "\t\t 0 == vmalloc\n"
+ "\t\t 1 == dma-contig");
+
#define VIMC_MDEV_MODEL_NAME "VIMC MDEV"
#define VIMC_ENT_LINK(src, srcpad, sink, sinkpad, link_flags) { \
@@ -278,6 +285,9 @@ static int vimc_probe(struct platform_device *pdev)
tpg_set_font(font->data);
+ if (vimc_allocator == VIMC_ALLOCATOR_DMA_CONTIG)
+ dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
+
vimc = kzalloc(sizeof(*vimc), GFP_KERNEL);
if (!vimc)
return -ENOMEM;
The vimc driver is used for testing purpose, and some test use cases involve sharing buffers with a consumer device. Consumers often require DMA contiguous memory, which vimc doesn't currently support. This leads in the best case to usage of bounce buffers, which is very slow, and in the worst case in a complete failure. Add support for the dma-contig allocator in vimc to support those use cases properly. The allocator is selected through a new "allocator" module parameter, which defaults to vmalloc. Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- Changes since v1: - Add vimc_allocator_type enum - Document the new parameter in vimc.rst --- Documentation/admin-guide/media/vimc.rst | 10 +++++++++- drivers/media/test-drivers/vimc/vimc-capture.c | 9 +++++++-- drivers/media/test-drivers/vimc/vimc-common.h | 7 +++++++ drivers/media/test-drivers/vimc/vimc-core.c | 10 ++++++++++ 4 files changed, 33 insertions(+), 3 deletions(-)