text: /*
   * Copyright (C) Fuzhou Rockchip Electronics Co.Ltd
   * Author:Mark Yao <mark.yao@rock-chips.com>
   *
   * This software is licensed under the terms of the GNU General Public
   * License version 2, as published by the Free Software Foundation, and
   * may be copied, distributed, and modified under those terms.
   *
   * 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.
   */
  
  #include <drm/drm.h>
  #include <drm/drmP.h>
  #include <drm/drm_gem.h>
  #include <drm/drm_vma_manager.h>
  #include <linux/iommu.h>
  
  #include "rockchip_drm_drv.h"
  #include "rockchip_drm_gem.h"
  
  static int rockchip_gem_iommu_map(struct rockchip_gem_object *rk_obj)
  {
  	struct drm_device *drm = rk_obj->base.dev;
  	struct rockchip_drm_private *private = drm->dev_private;
  	int prot = IOMMU_READ | IOMMU_WRITE;
  	ssize_t ret;
  
  	mutex_lock(&private->mm_lock);
  	ret = drm_mm_insert_node_generic(&private->mm, &rk_obj->mm,
  					 rk_obj->base.size, PAGE_SIZE,
  					 0, 0);
  	mutex_unlock(&private->mm_lock);
  
  	if (ret < 0) {
  		DRM_ERROR("out of I/O virtual memory: %zd\n", ret);
  		return ret;
  	}
  
  	rk_obj->dma_addr = rk_obj->mm.start;
  
  	ret = iommu_map_sg(private->domain, rk_obj->dma_addr, rk_obj->sgt->sgl,
  			   rk_obj->sgt->nents, prot);
  	if (ret < rk_obj->base.size) {
  		DRM_ERROR("failed to map buffer: size=%zd request_size=%zd\n",
  			  ret, rk_obj->base.size);
  		ret = -ENOMEM;
  		goto err_remove_node;
  	}
  
  	rk_obj->size = ret;
  
  	return 0;
  
  err_remove_node:
  	mutex_lock(&private->mm_lock);
  	drm_mm_remove_node(&rk_obj->mm);
  	mutex_unlock(&private->mm_lock);
  
  	return ret;
  }
  
  static int rockchip_gem_iommu_unmap(struct rockchip_gem_object *rk_obj)
  {
  	struct drm_device *drm = rk_obj->base.dev;
  	struct rockchip_drm_private *private = drm->dev_private;
  
  	iommu_unmap(private->domain, rk_obj->dma_addr, rk_obj->size);
  
  	mutex_lock(&private->mm_lock);
  
  	drm_mm_remove_node(&rk_obj->mm);
  
  	mutex_unlock(&private->mm_lock);
  
  	return 0;
  }
  
  static int rockchip_gem_get_pages(struct rockchip_gem_object *rk_obj)
  {
  	struct drm_device *drm = rk_obj->base.dev;
  	int ret, i;
  	struct scatterlist *s;
  
  	rk_obj->pages = drm_gem_get_pages(&rk_obj->base);
  	if (IS_ERR(rk_obj->pages))
  		return PTR_ERR(rk_obj->pages);
  
  	rk_obj->num_pages = rk_obj->base.size >> PAGE_SHIFT;
  
  	rk_obj->sgt = drm_prime_pages_to_sg(rk_obj->pages, rk_obj->num_pages);
  	if (IS_ERR(rk_obj->sgt)) {
  		ret = PTR_ERR(rk_obj->sgt);
  		goto err_put_pages;
  	}
  
  	/*
  	 * Fake up the SG table so that dma_sync_sg_for_device() can be used
  	 * to flush the pages associated with it.
  	 *
  	 * TODO: Replace this by drm_clflush_sg() once it can be implemented
  	 * without relying on symbols that are not exported.
  	 */
  	for_each_sg(rk_obj->sgt->sgl, s, rk_obj->sgt->nents, i)
  		sg_dma_address(s) = sg_phys(s);
  
  	dma_sync_sg_for_device(drm->dev, rk_obj->sgt->sgl, rk_obj->sgt->nents,
  			       DMA_TO_DEVICE);
  
  	return 0;
  
  err_put_pages:
  	drm_gem_put_pages(&rk_obj->base, rk_obj->pages, false, false);
  	return ret;
  }
  
  static void rockchip_gem_put_pages(struct rockchip_gem_object *rk_obj)
  {
  	sg_free_table(rk_obj->sgt);
  	kfree(rk_obj->sgt);
  	drm_gem_put_pages(&rk_obj->base, rk_obj->pages, true, true);
  }
  
  static int rockchip_gem_alloc_iommu(struct rockchip_gem_object *rk_obj,
  				    bool alloc_kmap)
  {
  	int ret;
  
  	ret = rockchip_gem_get_pages(rk_obj);
  	if (ret < 0)
  		return ret;
  
  	ret = rockchip_gem_iommu_map(rk_obj);
  	if (ret < 0)
  		goto err_free;
  
  	if (alloc_kmap) {
  		rk_obj->kvaddr = vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
  				      pgprot_writecombine(PAGE_KERNEL));
  		if (!rk_obj->kvaddr) {
  			DRM_ERROR("failed to vmap() buffer\n");
  			ret = -ENOMEM;
  			goto err_unmap;
  		}
  	}
  
  	return 0;
  
  err_unmap:
  	rockchip_gem_iommu_unmap(rk_obj);
  err_free:
  	rockchip_gem_put_pages(rk_obj);
  
  	return ret;
  }
  
  static int rockchip_gem_alloc_dma(struct rockchip_gem_object *rk_obj,
  				  bool alloc_kmap)
  {
  	struct drm_gem_object *obj = &rk_obj->base;
  	struct drm_device *drm = obj->dev;
  
  	rk_obj->dma_attrs = DMA_ATTR_WRITE_COMBINE;
  
  	if (!alloc_kmap)
  		rk_obj->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
  
  	rk_obj->kvaddr = dma_alloc_attrs(drm->dev, obj->size,
  					 &rk_obj->dma_addr, GFP_KERNEL,
  					 rk_obj->dma_attrs);
  	if (!rk_obj->kvaddr) {
  		DRM_ERROR("failed to allocate %zu byte dma buffer", obj->size);
  		return -ENOMEM;
  	}
  
  	return 0;
  }
  
  static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj,
  				  bool alloc_kmap)
  {
  	struct drm_gem_object *obj = &rk_obj->base;
  	struct drm_device *drm = obj->dev;
  	struct rockchip_drm_private *private = drm->dev_private;
  
  	if (private->domain)
  		return rockchip_gem_alloc_iommu(rk_obj, alloc_kmap);
  	else
  		return rockchip_gem_alloc_dma(rk_obj, alloc_kmap);
  }
  
  static void rockchip_gem_free_iommu(struct rockchip_gem_object *rk_obj)
  {
  	vunmap(rk_obj->kvaddr);
  	rockchip_gem_iommu_unmap(rk_obj);
  	rockchip_gem_put_pages(rk_obj);
  }
  
  static void rockchip_gem_free_dma(struct rockchip_gem_object *rk_obj)
  {
  	struct drm_gem_object *obj = &rk_obj->base;
  	struct drm_device *drm = obj->dev;
  
  	dma_free_attrs(drm->dev, obj->size, rk_obj->kvaddr, rk_obj->dma_addr,
  		       rk_obj->dma_attrs);
  }
  
  static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
  {
  	if (rk_obj->pages)
  		rockchip_gem_free_iommu(rk_obj);
  	else
  		rockchip_gem_free_dma(rk_obj);
  }
  
  static int rockchip_drm_gem_object_mmap_iommu(struct drm_gem_object *obj,
  					      struct vm_area_struct *vma)
  {
  	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
  	unsigned int i, count = obj->size >> PAGE_SHIFT;
  	unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
  	unsigned long uaddr = vma->vm_start;
  	unsigned long offset = vma->vm_pgoff;
  	unsigned long end = user_count + offset;
  	int ret;
  
  	if (user_count == 0)
  		return -ENXIO;
  	if (end > count)
  		return -ENXIO;
  
  	for (i = offset; i < end; i++) {
  		ret = vm_insert_page(vma, uaddr, rk_obj->pages[i]);
  		if (ret)
  			return ret;
  		uaddr += PAGE_SIZE;
  	}
  
  	return 0;
  }
  
  static int rockchip_drm_gem_object_mmap_dma(struct drm_gem_object *obj,
  					    struct vm_area_struct *vma)
  {
  	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
  	struct drm_device *drm = obj->dev;
  
  	return dma_mmap_attrs(drm->dev, vma, rk_obj->kvaddr, rk_obj->dma_addr,
  			      obj->size, rk_obj->dma_attrs);
  }
  
  static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
  					struct vm_area_struct *vma)
  {
  	int ret;
  	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
  
  	/*
  	 * We allocated a struct page table for rk_obj, so clear
  	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
  	 */
  	vma->vm_flags &= ~VM_PFNMAP;
  	vma->vm_pgoff = 0;
  
  	if (rk_obj->pages)
  		ret = rockchip_drm_gem_object_mmap_iommu(obj, vma);
  	else
  		ret = rockchip_drm_gem_object_mmap_dma(obj, vma);
  
  	if (ret)
  		drm_gem_vm_close(vma);
  
  	return ret;
  }
  
  int rockchip_gem_mmap_buf(struct drm_gem_object *obj,
  			  struct vm_area_struct *vma)
  {
  	int ret;
  
  	ret = drm_gem_mmap_obj(obj, obj->size, vma);
  	if (ret)
  		return ret;
  
  	return rockchip_drm_gem_object_mmap(obj, vma);
  }
  
  /* drm driver mmap file operations */
  int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
  {
  	struct drm_gem_object *obj;
  	int ret;
  
  	ret = drm_gem_mmap(filp, vma);
  	if (ret)
  		return ret;
  
  	obj = vma->vm_private_data;
  
  	return rockchip_drm_gem_object_mmap(obj, vma);
  }
  
  static void rockchip_gem_release_object(struct rockchip_gem_object *rk_obj)
  {
  	drm_gem_object_release(&rk_obj->base);
  	kfree(rk_obj);
  }
  
  struct rockchip_gem_object *
  	rockchip_gem_create_object(struct drm_device *drm, unsigned int size,
  				   bool alloc_kmap)
  {
  	struct rockchip_gem_object *rk_obj;
  	struct drm_gem_object *obj;
  	int ret;
  
  	size = round_up(size, PAGE_SIZE);
  
  	rk_obj = kzalloc(sizeof(*rk_obj), GFP_KERNEL);
  	if (!rk_obj)
  		return ERR_PTR(-ENOMEM);
  
  	obj = &rk_obj->base;
  
  	drm_gem_object_init(drm, obj, size);
  
  	ret = rockchip_gem_alloc_buf(rk_obj, alloc_kmap);
  	if (ret)
  		goto err_free_rk_obj;
  
  	return rk_obj;
  
  err_free_rk_obj:
  	rockchip_gem_release_object(rk_obj);
  	return ERR_PTR(ret);
  }
  
  /*
   * rockchip_gem_free_object - (struct drm_driver)->gem_free_object callback
   * function
   */
  void rockchip_gem_free_object(struct drm_gem_object *obj)
  {
  	struct rockchip_gem_object *rk_obj;
  
  	rk_obj = to_rockchip_obj(obj);
  
  	rockchip_gem_free_buf(rk_obj);
  
  	rockchip_gem_release_object(rk_obj);
  }
  
  /*
   * rockchip_gem_create_with_handle - allocate an object with the given
   * size and create a gem handle on it
   *
   * returns a struct rockchip_gem_object* on success or ERR_PTR values
   * on failure.
   */
  static struct rockchip_gem_object *
  rockchip_gem_create_with_handle(struct drm_file *file_priv,
  				struct drm_device *drm, unsigned int size,
  				unsigned int *handle)
  {
  	struct rockchip_gem_object *rk_obj;
  	struct drm_gem_object *obj;
  	int ret;
  
  	rk_obj = rockchip_gem_create_object(drm, size, false);
  	if (IS_ERR(rk_obj))
  		return ERR_CAST(rk_obj);
  
  	obj = &rk_obj->base;
  
  	/*
  	 * allocate a id of idr table where the obj is registered
  	 * and handle has the id what user can see.
  	 */
  	ret = drm_gem_handle_create(file_priv, obj, handle);
  	if (ret)
  		goto err_handle_create;
  
  	/* drop reference from allocate - handle holds it now. */
  	drm_gem_object_unreference_unlocked(obj);
  
  	return rk_obj;
  
  err_handle_create:
  	rockchip_gem_free_object(obj);
  
  	return ERR_PTR(ret);
  }
  
  int rockchip_gem_dumb_map_offset(struct drm_file *file_priv,
  				 struct drm_device *dev, uint32_t handle,
  				 uint64_t *offset)
  {
  	struct drm_gem_object *obj;
  	int ret;
  
  	obj = drm_gem_object_lookup(file_priv, handle);
  	if (!obj) {
  		DRM_ERROR("failed to lookup gem object.\n");
  		return -EINVAL;
  	}
  
  	ret = drm_gem_create_mmap_offset(obj);
  	if (ret)
  		goto out;
  
  	*offset = drm_vma_node_offset_addr(&obj->vma_node);
  	DRM_DEBUG_KMS("offset = 0x%llx\n", *offset);
  
  out:
  	drm_gem_object_unreference_unlocked(obj);
  
  	return 0;
  }
  
  /*
   * rockchip_gem_dumb_create - (struct drm_driver)->dumb_create callback
   * function
   *
   * This aligns the pitch and size arguments to the minimum required. wrap
   * this into your own function if you need bigger alignment.
   */
  int rockchip_gem_dumb_create(struct drm_file *file_priv,
  			     struct drm_device *dev,
  			     struct drm_mode_create_dumb *args)
  {
  	struct rockchip_gem_object *rk_obj;
  	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
  
  	/*
  	 * align to 64 bytes since Mali requires it.
  	 */
  	args->pitch = ALIGN(min_pitch, 64);
  	args->size = args->pitch * args->height;
  
  	rk_obj = rockchip_gem_create_with_handle(file_priv, dev, args->size,
  						 &args->handle);
  
  	return PTR_ERR_OR_ZERO(rk_obj);
  }
  
  /*
   * Allocate a sg_table for this GEM object.
   * Note: Both the table's contents, and the sg_table itself must be freed by
   *       the caller.
   * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
   */
  struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
  {
  	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
  	struct drm_device *drm = obj->dev;
  	struct sg_table *sgt;
  	int ret;
  
  	if (rk_obj->pages)
  		return drm_prime_pages_to_sg(rk_obj->pages, rk_obj->num_pages);
  
  	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
  	if (!sgt)
  		return ERR_PTR(-ENOMEM);
  
  	ret = dma_get_sgtable_attrs(drm->dev, sgt, rk_obj->kvaddr,
  				    rk_obj->dma_addr, obj->size,
  				    rk_obj->dma_attrs);
  	if (ret) {
  		DRM_ERROR("failed to allocate sgt, %d\n", ret);
  		kfree(sgt);
  		return ERR_PTR(ret);
  	}
  
  	return sgt;
  }
  
  void *rockchip_gem_prime_vmap(struct drm_gem_object *obj)
  {
  	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
  
  	if (rk_obj->pages)
  		return vmap(rk_obj->pages, rk_obj->num_pages, VM_MAP,
  			    pgprot_writecombine(PAGE_KERNEL));
  
  	if (rk_obj->dma_attrs & DMA_ATTR_NO_KERNEL_MAPPING)
  		return NULL;
  
  	return rk_obj->kvaddr;
  }
  
  void rockchip_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
  {
  	struct rockchip_gem_object *rk_obj = to_rockchip_obj(obj);
  
  	if (rk_obj->pages) {
  		vunmap(vaddr);
  		return;
  	}
  
  	/* Nothing to do if allocated by DMA mapping API. */
  }
  