Commit 92cd1440 authored by Dmitry Osipenko's avatar Dmitry Osipenko Committed by Mauro Carvalho Chehab
Browse files

media: staging: media: tegra-vde: Defer dmabuf's unmapping 



Frequent IOMMU remappings take about 50% of CPU usage because there is
quite a lot to remap. Defer dmabuf's unmapping by 5 seconds in order to
mitigate the mapping overhead which goes away completely and driver works
as fast as in a case of a disabled IOMMU. The case of a disabled IOMMU
should also benefit a tad from the caching since CPU cache maintenance
that happens on dmabuf's attaching takes some resources.

Signed-off-by: default avatarDmitry Osipenko <digetx@gmail.com>
Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent b301f8de

drivers/staging/media/tegra-vde/Makefile

+1 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

tegra-vde-y := vde.o iommu.o

tegra-vde-y := vde.o iommu.o dmabuf-cache.o

obj-$(CONFIG_TEGRA_VDE)	+= tegra-vde.o

drivers/staging/media/tegra-vde/dmabuf-cache.c

0 → 100644
+226 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0+

/*

 * NVIDIA Tegra Video decoder driver

 *

 * Copyright (C) 2016-2019 GRATE-DRIVER project

 */



#include <linux/dma-buf.h>

#include <linux/iova.h>

#include <linux/kernel.h>

#include <linux/list.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/workqueue.h>



#include "vde.h"



struct tegra_vde_cache_entry {

	enum dma_data_direction dma_dir;

	struct dma_buf_attachment *a;

	struct delayed_work dwork;

	struct tegra_vde *vde;

	struct list_head list;

	struct sg_table *sgt;

	struct iova *iova;

	unsigned int refcnt;

};



static void tegra_vde_release_entry(struct tegra_vde_cache_entry *entry)

{

	struct dma_buf *dmabuf = entry->a->dmabuf;



	WARN_ON_ONCE(entry->refcnt);



	if (entry->vde->domain)

		tegra_vde_iommu_unmap(entry->vde, entry->iova);



	dma_buf_unmap_attachment(entry->a, entry->sgt, entry->dma_dir);

	dma_buf_detach(dmabuf, entry->a);

	dma_buf_put(dmabuf);



	list_del(&entry->list);

	kfree(entry);

}



static void tegra_vde_delayed_unmap(struct work_struct *work)

{

	struct tegra_vde_cache_entry *entry;

	struct tegra_vde *vde;



	entry = container_of(work, struct tegra_vde_cache_entry,

			     dwork.work);

	vde = entry->vde;



	mutex_lock(&vde->map_lock);

	tegra_vde_release_entry(entry);

	mutex_unlock(&vde->map_lock);

}



int tegra_vde_dmabuf_cache_map(struct tegra_vde *vde,

			       struct dma_buf *dmabuf,

			       enum dma_data_direction dma_dir,

			       struct dma_buf_attachment **ap,

			       dma_addr_t *addrp)

{

	struct device *dev = vde->miscdev.parent;

	struct dma_buf_attachment *attachment;

	struct tegra_vde_cache_entry *entry;

	struct sg_table *sgt;

	struct iova *iova;

	int err;



	mutex_lock(&vde->map_lock);



	list_for_each_entry(entry, &vde->map_list, list) {

		if (entry->a->dmabuf != dmabuf)

			continue;



		if (!cancel_delayed_work(&entry->dwork))

			continue;



		if (entry->dma_dir != dma_dir)

			entry->dma_dir = DMA_BIDIRECTIONAL;



		dma_buf_put(dmabuf);



		if (vde->domain)

			*addrp = iova_dma_addr(&vde->iova, entry->iova);

		else

			*addrp = sg_dma_address(entry->sgt->sgl);



		goto ref;

	}



	attachment = dma_buf_attach(dmabuf, dev);

	if (IS_ERR(attachment)) {

		dev_err(dev, "Failed to attach dmabuf\n");

		err = PTR_ERR(attachment);

		goto err_unlock;

	}



	sgt = dma_buf_map_attachment(attachment, dma_dir);

	if (IS_ERR(sgt)) {

		dev_err(dev, "Failed to get dmabufs sg_table\n");

		err = PTR_ERR(sgt);

		goto err_detach;

	}



	if (!vde->domain && sgt->nents > 1) {

		dev_err(dev, "Sparse DMA region is unsupported, please enable IOMMU\n");

		err = -EINVAL;

		goto err_unmap;

	}



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

	if (!entry) {

		err = -ENOMEM;

		goto err_unmap;

	}



	if (vde->domain) {

		err = tegra_vde_iommu_map(vde, sgt, &iova, dmabuf->size);

		if (err)

			goto err_free;



		*addrp = iova_dma_addr(&vde->iova, iova);

	} else {

		*addrp = sg_dma_address(sgt->sgl);

		iova = NULL;

	}



	INIT_DELAYED_WORK(&entry->dwork, tegra_vde_delayed_unmap);

	list_add(&entry->list, &vde->map_list);



	entry->dma_dir = dma_dir;

	entry->iova = iova;

	entry->vde = vde;

	entry->sgt = sgt;

	entry->a = attachment;

ref:

	entry->refcnt++;



	*ap = entry->a;



	mutex_unlock(&vde->map_lock);



	return 0;



err_free:

	kfree(entry);

err_unmap:

	dma_buf_unmap_attachment(attachment, sgt, dma_dir);

err_detach:

	dma_buf_detach(dmabuf, attachment);

err_unlock:

	mutex_unlock(&vde->map_lock);



	return err;

}



void tegra_vde_dmabuf_cache_unmap(struct tegra_vde *vde,

				  struct dma_buf_attachment *a,

				  bool release)

{

	struct tegra_vde_cache_entry *entry;



	mutex_lock(&vde->map_lock);



	list_for_each_entry(entry, &vde->map_list, list) {

		if (entry->a != a)

			continue;



		WARN_ON_ONCE(!entry->refcnt);



		if (--entry->refcnt == 0) {

			if (release)

				tegra_vde_release_entry(entry);

			else

				schedule_delayed_work(&entry->dwork, 5 * HZ);

		}

		break;

	}



	mutex_unlock(&vde->map_lock);

}



void tegra_vde_dmabuf_cache_unmap_sync(struct tegra_vde *vde)

{

	struct tegra_vde_cache_entry *entry, *tmp;



	mutex_lock(&vde->map_lock);



	list_for_each_entry_safe(entry, tmp, &vde->map_list, list) {

		if (entry->refcnt)

			continue;



		if (!cancel_delayed_work(&entry->dwork))

			continue;



		tegra_vde_release_entry(entry);

	}



	mutex_unlock(&vde->map_lock);

}



void tegra_vde_dmabuf_cache_unmap_all(struct tegra_vde *vde)

{

	struct tegra_vde_cache_entry *entry, *tmp;



	mutex_lock(&vde->map_lock);



	while (!list_empty(&vde->map_list)) {

		list_for_each_entry_safe(entry, tmp, &vde->map_list, list) {

			if (!cancel_delayed_work(&entry->dwork))

				continue;



			tegra_vde_release_entry(entry);

		}



		mutex_unlock(&vde->map_lock);

		schedule();

		mutex_lock(&vde->map_lock);

	}



	mutex_unlock(&vde->map_lock);

}

drivers/staging/media/tegra-vde/iommu.c

+0 −2
Original line number Diff line number Diff line
@@ -19,7 +19,6 @@ 
int tegra_vde_iommu_map(struct tegra_vde *vde,

			struct sg_table *sgt,

			struct iova **iovap,

			dma_addr_t *addrp,

			size_t size)

{

	struct iova *iova;
@@ -45,7 +44,6 @@ int tegra_vde_iommu_map(struct tegra_vde *vde, 
	}



	*iovap = iova;

	*addrp = addr;



	return 0;

}

drivers/staging/media/tegra-vde/vde.c

+32 −111
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/genalloc.h>

#include <linux/interrupt.h>

#include <linux/iopoll.h>

#include <linux/list.h>

#include <linux/miscdevice.h>

#include <linux/module.h>

#include <linux/of_device.h>
@@ -37,18 +38,10 @@ 
#define BSE_DMA_BUSY		BIT(23)



struct video_frame {

	struct iova *y_iova;

	struct iova *cb_iova;

	struct iova *cr_iova;

	struct iova *aux_iova;

	struct dma_buf_attachment *y_dmabuf_attachment;

	struct dma_buf_attachment *cb_dmabuf_attachment;

	struct dma_buf_attachment *cr_dmabuf_attachment;

	struct dma_buf_attachment *aux_dmabuf_attachment;

	struct sg_table *y_sgt;

	struct sg_table *cb_sgt;

	struct sg_table *cr_sgt;

	struct sg_table *aux_sgt;

	dma_addr_t y_addr;

	dma_addr_t cb_addr;

	dma_addr_t cr_addr;
@@ -494,22 +487,6 @@ static void tegra_vde_decode_frame(struct tegra_vde *vde, 
			 vde->sxe, 0x00);

}



static void tegra_vde_detach_and_put_dmabuf(struct tegra_vde *vde,

					    enum dma_data_direction dma_dir,

					    struct dma_buf_attachment *a,

					    struct sg_table *sgt,

					    struct iova *iova)

{

	struct dma_buf *dmabuf = a->dmabuf;



	if (vde->domain)

		tegra_vde_iommu_unmap(vde, iova);



	dma_buf_unmap_attachment(a, sgt, dma_dir);

	dma_buf_detach(dmabuf, a);

	dma_buf_put(dmabuf);

}



static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,

				   int fd,

				   unsigned long offset,
@@ -517,15 +494,11 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde *vde, 
				   size_t align_size,

				   struct dma_buf_attachment **a,

				   dma_addr_t *addrp,

				   struct sg_table **s,

				   struct iova **iovap,

				   size_t *size,

				   enum dma_data_direction dma_dir)

{

	struct device *dev = vde->miscdev.parent;

	struct dma_buf_attachment *attachment;

	struct dma_buf *dmabuf;

	struct sg_table *sgt;

	int err;



	dmabuf = dma_buf_get(fd);
@@ -546,49 +519,17 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde *vde, 
		return -EINVAL;

	}



	attachment = dma_buf_attach(dmabuf, dev);

	if (IS_ERR(attachment)) {

		dev_err(dev, "Failed to attach dmabuf\n");

		err = PTR_ERR(attachment);

	err = tegra_vde_dmabuf_cache_map(vde, dmabuf, dma_dir, a, addrp);

	if (err)

		goto err_put;

	}



	sgt = dma_buf_map_attachment(attachment, dma_dir);

	if (IS_ERR(sgt)) {

		dev_err(dev, "Failed to get dmabufs sg_table\n");

		err = PTR_ERR(sgt);

		goto err_detach;

	}



	if (!vde->domain && sgt->nents > 1) {

		dev_err(dev, "Sparse DMA region is unsupported, please enable IOMMU\n");

		err = -EINVAL;

		goto err_unmap;

	}



	if (vde->domain) {

		err = tegra_vde_iommu_map(vde, sgt, iovap, addrp, dmabuf->size);

		if (err) {

			dev_err(dev, "IOMMU mapping failed: %d\n", err);

			goto err_unmap;

		}

	} else {

		*addrp = sg_dma_address(sgt->sgl);

	}



	*addrp = *addrp + offset;

	*a = attachment;

	*s = sgt;



	if (size)

		*size = dmabuf->size - offset;



	return 0;



err_unmap:

	dma_buf_unmap_attachment(attachment, sgt, dma_dir);

err_detach:

	dma_buf_detach(dmabuf, attachment);

err_put:

	dma_buf_put(dmabuf);
@@ -608,8 +549,6 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde, 
				      src->y_offset, lsize, SZ_256,

				      &frame->y_dmabuf_attachment,

				      &frame->y_addr,

				      &frame->y_sgt,

				      &frame->y_iova,

				      NULL, dma_dir);

	if (err)

		return err;
@@ -618,8 +557,6 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde, 
				      src->cb_offset, csize, SZ_256,

				      &frame->cb_dmabuf_attachment,

				      &frame->cb_addr,

				      &frame->cb_sgt,

				      &frame->cb_iova,

				      NULL, dma_dir);

	if (err)

		goto err_release_y;
@@ -628,8 +565,6 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde, 
				      src->cr_offset, csize, SZ_256,

				      &frame->cr_dmabuf_attachment,

				      &frame->cr_addr,

				      &frame->cr_sgt,

				      &frame->cr_iova,

				      NULL, dma_dir);

	if (err)

		goto err_release_cb;
@@ -643,8 +578,6 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde, 
				      src->aux_offset, csize, SZ_256,

				      &frame->aux_dmabuf_attachment,

				      &frame->aux_addr,

				      &frame->aux_sgt,

				      &frame->aux_iova,

				      NULL, dma_dir);

	if (err)

		goto err_release_cr;
@@ -652,20 +585,11 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde, 
	return 0;



err_release_cr:

	tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

					frame->cr_dmabuf_attachment,

					frame->cr_sgt,

					frame->cr_iova);

	tegra_vde_dmabuf_cache_unmap(vde, frame->cr_dmabuf_attachment, true);

err_release_cb:

	tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

					frame->cb_dmabuf_attachment,

					frame->cb_sgt,

					frame->cb_iova);

	tegra_vde_dmabuf_cache_unmap(vde, frame->cb_dmabuf_attachment, true);

err_release_y:

	tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

					frame->y_dmabuf_attachment,

					frame->y_sgt,

					frame->y_iova);

	tegra_vde_dmabuf_cache_unmap(vde, frame->y_dmabuf_attachment, true);



	return err;

}
@@ -673,28 +597,16 @@ err_release_y: 
static void tegra_vde_release_frame_dmabufs(struct tegra_vde *vde,

					    struct video_frame *frame,

					    enum dma_data_direction dma_dir,

					    bool baseline_profile)

					    bool baseline_profile,

					    bool release)

{

	if (!baseline_profile)

		tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

						frame->aux_dmabuf_attachment,

						frame->aux_sgt,

						frame->aux_iova);

		tegra_vde_dmabuf_cache_unmap(vde, frame->aux_dmabuf_attachment,

					     release);



	tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

					frame->cr_dmabuf_attachment,

					frame->cr_sgt,

					frame->cr_iova);



	tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

					frame->cb_dmabuf_attachment,

					frame->cb_sgt,

					frame->cb_iova);



	tegra_vde_detach_and_put_dmabuf(vde, dma_dir,

					frame->y_dmabuf_attachment,

					frame->y_sgt,

					frame->y_iova);

	tegra_vde_dmabuf_cache_unmap(vde, frame->cr_dmabuf_attachment, release);

	tegra_vde_dmabuf_cache_unmap(vde, frame->cb_dmabuf_attachment, release);

	tegra_vde_dmabuf_cache_unmap(vde, frame->y_dmabuf_attachment, release);

}



static int tegra_vde_validate_frame(struct device *dev,
@@ -786,8 +698,6 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, 
	struct tegra_vde_h264_frame __user *frames_user;

	struct video_frame *dpb_frames;

	struct dma_buf_attachment *bitstream_data_dmabuf_attachment;

	struct sg_table *bitstream_sgt;

	struct iova *bitstream_iova;

	enum dma_data_direction dma_dir;

	dma_addr_t bitstream_data_addr;

	dma_addr_t bsev_ptr;
@@ -812,8 +722,6 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde, 
				      SZ_16K, SZ_16K,

				      &bitstream_data_dmabuf_attachment,

				      &bitstream_data_addr,

				      &bitstream_sgt,

				      &bitstream_iova,

				      &bitstream_data_size,

				      DMA_TO_DEVICE);

	if (ret)
@@ -944,7 +852,7 @@ release_dpb_frames: 
		dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;



		tegra_vde_release_frame_dmabufs(vde, &dpb_frames[i], dma_dir,

						ctx.baseline_profile);

						ctx.baseline_profile, ret != 0);

	}



free_dpb_frames:
@@ -954,10 +862,8 @@ free_frames: 
	kfree(frames);



release_bitstream_dmabuf:

	tegra_vde_detach_and_put_dmabuf(vde, DMA_TO_DEVICE,

					bitstream_data_dmabuf_attachment,

					bitstream_sgt,

					bitstream_iova);

	tegra_vde_dmabuf_cache_unmap(vde, bitstream_data_dmabuf_attachment,

				     ret != 0);



	return ret;

}
@@ -979,9 +885,21 @@ static long tegra_vde_unlocked_ioctl(struct file *filp, 
	return -ENOTTY;

}



static int tegra_vde_release_file(struct inode *inode, struct file *filp)

{

	struct miscdevice *miscdev = filp->private_data;

	struct tegra_vde *vde = container_of(miscdev, struct tegra_vde,

					     miscdev);



	tegra_vde_dmabuf_cache_unmap_sync(vde);



	return 0;

}



static const struct file_operations tegra_vde_fops = {

	.owner		= THIS_MODULE,

	.unlocked_ioctl	= tegra_vde_unlocked_ioctl,

	.release	= tegra_vde_release_file,

};



static irqreturn_t tegra_vde_isr(int irq, void *data)
@@ -1159,6 +1077,8 @@ static int tegra_vde_probe(struct platform_device *pdev) 
		return -ENOMEM;

	}



	INIT_LIST_HEAD(&vde->map_list);

	mutex_init(&vde->map_lock);

	mutex_init(&vde->lock);

	init_completion(&vde->decode_completion);
@@ -1221,6 +1141,7 @@ static int tegra_vde_remove(struct platform_device *pdev) 


	misc_deregister(&vde->miscdev);



	tegra_vde_dmabuf_cache_unmap_all(vde);

	tegra_vde_iommu_deinit(vde);



	gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,

drivers/staging/media/tegra-vde/vde.h

+17 −1
Original line number Diff line number Diff line
@@ -9,16 +9,20 @@ 
#define TEGRA_VDE_H



#include <linux/completion.h>

#include <linux/dma-direction.h>

#include <linux/list.h>

#include <linux/miscdevice.h>

#include <linux/mutex.h>

#include <linux/types.h>

#include <linux/iova.h>



struct clk;

struct dma_buf;

struct gen_pool;

struct iommu_group;

struct iommu_domain;

struct reset_control;

struct dma_buf_attachment;



struct tegra_vde {

	void __iomem *sxe;
@@ -31,6 +35,8 @@ struct tegra_vde { 
	void __iomem *vdma;

	void __iomem *frameid;

	struct mutex lock;

	struct mutex map_lock;

	struct list_head map_list;

	struct miscdevice miscdev;

	struct reset_control *rst;

	struct reset_control *rst_mc;
@@ -51,10 +57,20 @@ void tegra_vde_iommu_deinit(struct tegra_vde *vde); 
int tegra_vde_iommu_map(struct tegra_vde *vde,

			struct sg_table *sgt,

			struct iova **iovap,

			dma_addr_t *addrp,

			size_t size);

void tegra_vde_iommu_unmap(struct tegra_vde *vde, struct iova *iova);



int tegra_vde_dmabuf_cache_map(struct tegra_vde *vde,

			       struct dma_buf *dmabuf,

			       enum dma_data_direction dma_dir,

			       struct dma_buf_attachment **ap,

			       dma_addr_t *addrp);

void tegra_vde_dmabuf_cache_unmap(struct tegra_vde *vde,

				  struct dma_buf_attachment *a,

				  bool release);

void tegra_vde_dmabuf_cache_unmap_sync(struct tegra_vde *vde);

void tegra_vde_dmabuf_cache_unmap_all(struct tegra_vde *vde);



static __maybe_unused char const *

tegra_vde_reg_base_name(struct tegra_vde *vde, void __iomem *base)

{

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