drivers/gpu/drm/etnaviv/etnaviv_mmu.c - kernel/quantenna - Git at Google

 /*
  * Copyright (C) 2015 Etnaviv Project
  *
  * 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 "etnaviv_drv.h"
 #include "etnaviv_gem.h"
 #include "etnaviv_gpu.h"
 #include "etnaviv_mmu.h"

 static int etnaviv_fault_handler(struct iommu_domain *iommu, struct device *dev,
 		unsigned long iova, int flags, void *arg)
 {
 	DBG("*** fault: iova=%08lx, flags=%d", iova, flags);
 	return 0;
 }

 int etnaviv_iommu_map(struct etnaviv_iommu *iommu, u32 iova,
 		struct sg_table *sgt, unsigned len, int prot)
 {
 	struct iommu_domain *domain = iommu->domain;
 	struct scatterlist *sg;
 	unsigned int da = iova;
 	unsigned int i, j;
 	int ret;

 	if (!domain || !sgt)
 		return -EINVAL;

 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 		u32 pa = sg_dma_address(sg) - sg->offset;
 		size_t bytes = sg_dma_len(sg) + sg->offset;

 		VERB("map[%d]: %08x %08x(%zx)", i, iova, pa, bytes);

 		ret = iommu_map(domain, da, pa, bytes, prot);
 		if (ret)
 			goto fail;

 		da += bytes;
 	}

 	return 0;

 fail:
 	da = iova;

 	for_each_sg(sgt->sgl, sg, i, j) {
 		size_t bytes = sg_dma_len(sg) + sg->offset;

 		iommu_unmap(domain, da, bytes);
 		da += bytes;
 	}
 	return ret;
 }

 int etnaviv_iommu_unmap(struct etnaviv_iommu *iommu, u32 iova,
 		struct sg_table *sgt, unsigned len)
 {
 	struct iommu_domain *domain = iommu->domain;
 	struct scatterlist *sg;
 	unsigned int da = iova;
 	int i;

 	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
 		size_t bytes = sg_dma_len(sg) + sg->offset;
 		size_t unmapped;

 		unmapped = iommu_unmap(domain, da, bytes);
 		if (unmapped < bytes)
 			return unmapped;

 		VERB("unmap[%d]: %08x(%zx)", i, iova, bytes);

 		BUG_ON(!PAGE_ALIGNED(bytes));

 		da += bytes;
 	}

 	return 0;
 }

 static void etnaviv_iommu_remove_mapping(struct etnaviv_iommu *mmu,
 	struct etnaviv_vram_mapping *mapping)
 {
 	struct etnaviv_gem_object *etnaviv_obj = mapping->object;

 	etnaviv_iommu_unmap(mmu, mapping->vram_node.start,
 			    etnaviv_obj->sgt, etnaviv_obj->base.size);
 	drm_mm_remove_node(&mapping->vram_node);
 }

 int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
 	struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
 	struct etnaviv_vram_mapping *mapping)
 {
 	struct etnaviv_vram_mapping *free = NULL;
 	struct sg_table *sgt = etnaviv_obj->sgt;
 	struct drm_mm_node *node;
 	int ret;

 	lockdep_assert_held(&etnaviv_obj->lock);

 	mutex_lock(&mmu->lock);

 	/* v1 MMU can optimize single entry (contiguous) scatterlists */
 	if (sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
 		u32 iova;

 		iova = sg_dma_address(sgt->sgl) - memory_base;
 		if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
 			mapping->iova = iova;
 			list_add_tail(&mapping->mmu_node, &mmu->mappings);
 			mutex_unlock(&mmu->lock);
 			return 0;
 		}
 	}

 	node = &mapping->vram_node;
 	while (1) {
 		struct etnaviv_vram_mapping *m, *n;
 		struct list_head list;
 		bool found;

 		ret = drm_mm_insert_node_in_range(&mmu->mm, node,
 			etnaviv_obj->base.size, 0, mmu->last_iova, ~0UL,
 			DRM_MM_SEARCH_DEFAULT);

 		if (ret != -ENOSPC)
 			break;

 		/*
 		 * If we did not search from the start of the MMU region,
 		 * try again in case there are free slots.
 		 */
 		if (mmu->last_iova) {
 			mmu->last_iova = 0;
 			mmu->need_flush = true;
 			continue;
 		}

 		/* Try to retire some entries */
 		drm_mm_init_scan(&mmu->mm, etnaviv_obj->base.size, 0, 0);

 		found = 0;
 		INIT_LIST_HEAD(&list);
 		list_for_each_entry(free, &mmu->mappings, mmu_node) {
 			/* If this vram node has not been used, skip this. */
 			if (!free->vram_node.mm)
 				continue;

 			/*
 			 * If the iova is pinned, then it's in-use,
 			 * so we must keep its mapping.
 			 */
 			if (free->use)
 				continue;

 			list_add(&free->scan_node, &list);
 			if (drm_mm_scan_add_block(&free->vram_node)) {
 				found = true;
 				break;
 			}
 		}

 		if (!found) {
 			/* Nothing found, clean up and fail */
 			list_for_each_entry_safe(m, n, &list, scan_node)
 				BUG_ON(drm_mm_scan_remove_block(&m->vram_node));
 			break;
 		}

 		/*
 		 * drm_mm does not allow any other operations while
 		 * scanning, so we have to remove all blocks first.
 		 * If drm_mm_scan_remove_block() returns false, we
 		 * can leave the block pinned.
 		 */
 		list_for_each_entry_safe(m, n, &list, scan_node)
 			if (!drm_mm_scan_remove_block(&m->vram_node))
 				list_del_init(&m->scan_node);

 		/*
 		 * Unmap the blocks which need to be reaped from the MMU.
 		 * Clear the mmu pointer to prevent the mapping_get finding
 		 * this mapping.
 		 */
 		list_for_each_entry_safe(m, n, &list, scan_node) {
 			etnaviv_iommu_remove_mapping(mmu, m);
 			m->mmu = NULL;
 			list_del_init(&m->mmu_node);
 			list_del_init(&m->scan_node);
 		}

 		/*
 		 * We removed enough mappings so that the new allocation will
 		 * succeed.  Ensure that the MMU will be flushed before the
 		 * associated commit requesting this mapping, and retry the
 		 * allocation one more time.
 		 */
 		mmu->need_flush = true;
 	}

 	if (ret < 0) {
 		mutex_unlock(&mmu->lock);
 		return ret;
 	}

 	mmu->last_iova = node->start + etnaviv_obj->base.size;
 	mapping->iova = node->start;
 	ret = etnaviv_iommu_map(mmu, node->start, sgt, etnaviv_obj->base.size,
 				IOMMU_READ | IOMMU_WRITE);

 	if (ret < 0) {
 		drm_mm_remove_node(node);
 		mutex_unlock(&mmu->lock);
 		return ret;
 	}

 	list_add_tail(&mapping->mmu_node, &mmu->mappings);
 	mutex_unlock(&mmu->lock);

 	return ret;
 }

 void etnaviv_iommu_unmap_gem(struct etnaviv_iommu *mmu,
 	struct etnaviv_vram_mapping *mapping)
 {
 	WARN_ON(mapping->use);

 	mutex_lock(&mmu->lock);

 	/* If the vram node is on the mm, unmap and remove the node */
 	if (mapping->vram_node.mm == &mmu->mm)
 		etnaviv_iommu_remove_mapping(mmu, mapping);

 	list_del(&mapping->mmu_node);
 	mutex_unlock(&mmu->lock);
 }

 void etnaviv_iommu_destroy(struct etnaviv_iommu *mmu)
 {
 	drm_mm_takedown(&mmu->mm);
 	iommu_domain_free(mmu->domain);
 	kfree(mmu);
 }

 struct etnaviv_iommu *etnaviv_iommu_new(struct etnaviv_gpu *gpu,
 	struct iommu_domain *domain, enum etnaviv_iommu_version version)
 {
 	struct etnaviv_iommu *mmu;

 	mmu = kzalloc(sizeof(*mmu), GFP_KERNEL);
 	if (!mmu)
 		return ERR_PTR(-ENOMEM);

 	mmu->domain = domain;
 	mmu->gpu = gpu;
 	mmu->version = version;
 	mutex_init(&mmu->lock);
 	INIT_LIST_HEAD(&mmu->mappings);

 	drm_mm_init(&mmu->mm, domain->geometry.aperture_start,
 		    domain->geometry.aperture_end -
 		      domain->geometry.aperture_start + 1);

 	iommu_set_fault_handler(domain, etnaviv_fault_handler, gpu->dev);

 	return mmu;
 }

 size_t etnaviv_iommu_dump_size(struct etnaviv_iommu *iommu)
 {
 	struct etnaviv_iommu_ops *ops;

 	ops = container_of(iommu->domain->ops, struct etnaviv_iommu_ops, ops);

 	return ops->dump_size(iommu->domain);
 }

 void etnaviv_iommu_dump(struct etnaviv_iommu *iommu, void *buf)
 {
 	struct etnaviv_iommu_ops *ops;

 	ops = container_of(iommu->domain->ops, struct etnaviv_iommu_ops, ops);

 	ops->dump(iommu->domain, buf);
 }
	/*
	* Copyright (C) 2015 Etnaviv Project
	*
	* 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 "etnaviv_drv.h"
	#include "etnaviv_gem.h"
	#include "etnaviv_gpu.h"
	#include "etnaviv_mmu.h"

	static int etnaviv_fault_handler(struct iommu_domain iommu, struct device dev,
	unsigned long iova, int flags, void *arg)
	{
	DBG("*** fault: iova=%08lx, flags=%d", iova, flags);
	return 0;
	}

	int etnaviv_iommu_map(struct etnaviv_iommu *iommu, u32 iova,
	struct sg_table *sgt, unsigned len, int prot)
	{
	struct iommu_domain *domain = iommu->domain;
	struct scatterlist *sg;
	unsigned int da = iova;
	unsigned int i, j;
	int ret;

	if (!domain \|\| !sgt)
	return -EINVAL;

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
	u32 pa = sg_dma_address(sg) - sg->offset;
	size_t bytes = sg_dma_len(sg) + sg->offset;

	VERB("map[%d]: %08x %08x(%zx)", i, iova, pa, bytes);

	ret = iommu_map(domain, da, pa, bytes, prot);
	if (ret)
	goto fail;

	da += bytes;
	}

	return 0;

	fail:
	da = iova;

	for_each_sg(sgt->sgl, sg, i, j) {
	size_t bytes = sg_dma_len(sg) + sg->offset;

	iommu_unmap(domain, da, bytes);
	da += bytes;
	}
	return ret;
	}

	int etnaviv_iommu_unmap(struct etnaviv_iommu *iommu, u32 iova,
	struct sg_table *sgt, unsigned len)
	{
	struct iommu_domain *domain = iommu->domain;
	struct scatterlist *sg;
	unsigned int da = iova;
	int i;

	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
	size_t bytes = sg_dma_len(sg) + sg->offset;
	size_t unmapped;

	unmapped = iommu_unmap(domain, da, bytes);
	if (unmapped < bytes)
	return unmapped;

	VERB("unmap[%d]: %08x(%zx)", i, iova, bytes);

	BUG_ON(!PAGE_ALIGNED(bytes));

	da += bytes;
	}

	return 0;
	}

	static void etnaviv_iommu_remove_mapping(struct etnaviv_iommu *mmu,
	struct etnaviv_vram_mapping *mapping)
	{
	struct etnaviv_gem_object *etnaviv_obj = mapping->object;

	etnaviv_iommu_unmap(mmu, mapping->vram_node.start,
	etnaviv_obj->sgt, etnaviv_obj->base.size);
	drm_mm_remove_node(&mapping->vram_node);
	}

	int etnaviv_iommu_map_gem(struct etnaviv_iommu *mmu,
	struct etnaviv_gem_object *etnaviv_obj, u32 memory_base,
	struct etnaviv_vram_mapping *mapping)
	{
	struct etnaviv_vram_mapping *free = NULL;
	struct sg_table *sgt = etnaviv_obj->sgt;
	struct drm_mm_node *node;
	int ret;

	lockdep_assert_held(&etnaviv_obj->lock);

	mutex_lock(&mmu->lock);

	/* v1 MMU can optimize single entry (contiguous) scatterlists */
	if (sgt->nents == 1 && !(etnaviv_obj->flags & ETNA_BO_FORCE_MMU)) {
	u32 iova;

	iova = sg_dma_address(sgt->sgl) - memory_base;
	if (iova < 0x80000000 - sg_dma_len(sgt->sgl)) {
	mapping->iova = iova;
	list_add_tail(&mapping->mmu_node, &mmu->mappings);
	mutex_unlock(&mmu->lock);
	return 0;
	}
	}

	node = &mapping->vram_node;
	while (1) {
	struct etnaviv_vram_mapping m, n;
	struct list_head list;
	bool found;

	ret = drm_mm_insert_node_in_range(&mmu->mm, node,
	etnaviv_obj->base.size, 0, mmu->last_iova, ~0UL,
	DRM_MM_SEARCH_DEFAULT);

	if (ret != -ENOSPC)
	break;

	/*
	* If we did not search from the start of the MMU region,
	* try again in case there are free slots.
	*/
	if (mmu->last_iova) {
	mmu->last_iova = 0;
	mmu->need_flush = true;
	continue;
	}

	/* Try to retire some entries */
	drm_mm_init_scan(&mmu->mm, etnaviv_obj->base.size, 0, 0);

	found = 0;
	INIT_LIST_HEAD(&list);
	list_for_each_entry(free, &mmu->mappings, mmu_node) {
	/* If this vram node has not been used, skip this. */
	if (!free->vram_node.mm)
	continue;

	/*
	* If the iova is pinned, then it's in-use,
	* so we must keep its mapping.
	*/
	if (free->use)
	continue;

	list_add(&free->scan_node, &list);
	if (drm_mm_scan_add_block(&free->vram_node)) {
	found = true;
	break;
	}
	}

	if (!found) {
	/* Nothing found, clean up and fail */
	list_for_each_entry_safe(m, n, &list, scan_node)
	BUG_ON(drm_mm_scan_remove_block(&m->vram_node));
	break;
	}

	/*
	* drm_mm does not allow any other operations while
	* scanning, so we have to remove all blocks first.
	* If drm_mm_scan_remove_block() returns false, we
	* can leave the block pinned.
	*/
	list_for_each_entry_safe(m, n, &list, scan_node)
	if (!drm_mm_scan_remove_block(&m->vram_node))
	list_del_init(&m->scan_node);

	/*
	* Unmap the blocks which need to be reaped from the MMU.
	* Clear the mmu pointer to prevent the mapping_get finding
	* this mapping.
	*/
	list_for_each_entry_safe(m, n, &list, scan_node) {
	etnaviv_iommu_remove_mapping(mmu, m);
	m->mmu = NULL;
	list_del_init(&m->mmu_node);
	list_del_init(&m->scan_node);
	}

	/*
	* We removed enough mappings so that the new allocation will
	* succeed. Ensure that the MMU will be flushed before the
	* associated commit requesting this mapping, and retry the
	* allocation one more time.
	*/
	mmu->need_flush = true;
	}

	if (ret < 0) {
	mutex_unlock(&mmu->lock);
	return ret;
	}

	mmu->last_iova = node->start + etnaviv_obj->base.size;
	mapping->iova = node->start;
	ret = etnaviv_iommu_map(mmu, node->start, sgt, etnaviv_obj->base.size,
	IOMMU_READ \| IOMMU_WRITE);

	if (ret < 0) {
	drm_mm_remove_node(node);
	mutex_unlock(&mmu->lock);
	return ret;
	}

	list_add_tail(&mapping->mmu_node, &mmu->mappings);
	mutex_unlock(&mmu->lock);

	return ret;
	}

	void etnaviv_iommu_unmap_gem(struct etnaviv_iommu *mmu,
	struct etnaviv_vram_mapping *mapping)
	{
	WARN_ON(mapping->use);

	mutex_lock(&mmu->lock);

	/* If the vram node is on the mm, unmap and remove the node */
	if (mapping->vram_node.mm == &mmu->mm)
	etnaviv_iommu_remove_mapping(mmu, mapping);

	list_del(&mapping->mmu_node);
	mutex_unlock(&mmu->lock);
	}

	void etnaviv_iommu_destroy(struct etnaviv_iommu *mmu)
	{
	drm_mm_takedown(&mmu->mm);
	iommu_domain_free(mmu->domain);
	kfree(mmu);
	}

	struct etnaviv_iommu etnaviv_iommu_new(struct etnaviv_gpu gpu,
	struct iommu_domain *domain, enum etnaviv_iommu_version version)
	{
	struct etnaviv_iommu *mmu;

	mmu = kzalloc(sizeof(*mmu), GFP_KERNEL);
	if (!mmu)
	return ERR_PTR(-ENOMEM);

	mmu->domain = domain;
	mmu->gpu = gpu;
	mmu->version = version;
	mutex_init(&mmu->lock);
	INIT_LIST_HEAD(&mmu->mappings);

	drm_mm_init(&mmu->mm, domain->geometry.aperture_start,
	domain->geometry.aperture_end -
	domain->geometry.aperture_start + 1);

	iommu_set_fault_handler(domain, etnaviv_fault_handler, gpu->dev);

	return mmu;
	}

	size_t etnaviv_iommu_dump_size(struct etnaviv_iommu *iommu)
	{
	struct etnaviv_iommu_ops *ops;

	ops = container_of(iommu->domain->ops, struct etnaviv_iommu_ops, ops);

	return ops->dump_size(iommu->domain);
	}

	void etnaviv_iommu_dump(struct etnaviv_iommu iommu, void buf)
	{
	struct etnaviv_iommu_ops *ops;

	ops = container_of(iommu->domain->ops, struct etnaviv_iommu_ops, ops);

	ops->dump(iommu->domain, buf);
	}