text: /*
   * Copyright (C) 2017 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 <drm/drm_mm.h>
  
  #include "etnaviv_cmdbuf.h"
  #include "etnaviv_gpu.h"
  #include "etnaviv_mmu.h"
  #include "etnaviv_perfmon.h"
  
  #define SUBALLOC_SIZE		SZ_256K
  #define SUBALLOC_GRANULE	SZ_4K
  #define SUBALLOC_GRANULES	(SUBALLOC_SIZE / SUBALLOC_GRANULE)
  
  struct etnaviv_cmdbuf_suballoc {
  	/* suballocated dma buffer properties */
  	struct etnaviv_gpu *gpu;
  	void *vaddr;
  	dma_addr_t paddr;
  
  	/* GPU mapping */
  	u32 iova;
  	struct drm_mm_node vram_node; /* only used on MMUv2 */
  
  	/* allocation management */
  	struct mutex lock;
  	DECLARE_BITMAP(granule_map, SUBALLOC_GRANULES);
  	int free_space;
  	wait_queue_head_t free_event;
  };
  
  struct etnaviv_cmdbuf_suballoc *
  etnaviv_cmdbuf_suballoc_new(struct etnaviv_gpu * gpu)
  {
  	struct etnaviv_cmdbuf_suballoc *suballoc;
  	int ret;
  
  	suballoc = kzalloc(sizeof(*suballoc), GFP_KERNEL);
  	if (!suballoc)
  		return ERR_PTR(-ENOMEM);
  
  	suballoc->gpu = gpu;
  	mutex_init(&suballoc->lock);
  	init_waitqueue_head(&suballoc->free_event);
  
  	suballoc->vaddr = dma_alloc_wc(gpu->dev, SUBALLOC_SIZE,
  				       &suballoc->paddr, GFP_KERNEL);
  	if (!suballoc->vaddr)
  		goto free_suballoc;
  
  	ret = etnaviv_iommu_get_suballoc_va(gpu, suballoc->paddr,
  					    &suballoc->vram_node, SUBALLOC_SIZE,
  					    &suballoc->iova);
  	if (ret)
  		goto free_dma;
  
  	return suballoc;
  
  free_dma:
  	dma_free_wc(gpu->dev, SUBALLOC_SIZE, suballoc->vaddr, suballoc->paddr);
  free_suballoc:
  	kfree(suballoc);
  
  	return NULL;
  }
  
  void etnaviv_cmdbuf_suballoc_destroy(struct etnaviv_cmdbuf_suballoc *suballoc)
  {
  	etnaviv_iommu_put_suballoc_va(suballoc->gpu, &suballoc->vram_node,
  				      SUBALLOC_SIZE, suballoc->iova);
  	dma_free_wc(suballoc->gpu->dev, SUBALLOC_SIZE, suballoc->vaddr,
  		    suballoc->paddr);
  	kfree(suballoc);
  }
  
  struct etnaviv_cmdbuf *
  etnaviv_cmdbuf_new(struct etnaviv_cmdbuf_suballoc *suballoc, u32 size,
  		   size_t nr_bos, size_t nr_pmrs)
  {
  	struct etnaviv_cmdbuf *cmdbuf;
  	struct etnaviv_perfmon_request *pmrs;
  	size_t sz = size_vstruct(nr_bos, sizeof(cmdbuf->bo_map[0]),
  				 sizeof(*cmdbuf));
  	int granule_offs, order, ret;
  
  	cmdbuf = kzalloc(sz, GFP_KERNEL);
  	if (!cmdbuf)
  		return NULL;
  
  	sz = sizeof(*pmrs) * nr_pmrs;
  	pmrs = kzalloc(sz, GFP_KERNEL);
  	if (!pmrs)
  		goto out_free_cmdbuf;
  
  	cmdbuf->pmrs = pmrs;
  	cmdbuf->suballoc = suballoc;
  	cmdbuf->size = size;
  
  	order = order_base_2(ALIGN(size, SUBALLOC_GRANULE) / SUBALLOC_GRANULE);
  retry:
  	mutex_lock(&suballoc->lock);
  	granule_offs = bitmap_find_free_region(suballoc->granule_map,
  					SUBALLOC_GRANULES, order);
  	if (granule_offs < 0) {
  		suballoc->free_space = 0;
  		mutex_unlock(&suballoc->lock);
  		ret = wait_event_interruptible_timeout(suballoc->free_event,
  						       suballoc->free_space,
  						       msecs_to_jiffies(10 * 1000));
  		if (!ret) {
  			dev_err(suballoc->gpu->dev,
  				"Timeout waiting for cmdbuf space\n");
  			return NULL;
  		}
  		goto retry;
  	}
  	mutex_unlock(&suballoc->lock);
  	cmdbuf->suballoc_offset = granule_offs * SUBALLOC_GRANULE;
  	cmdbuf->vaddr = suballoc->vaddr + cmdbuf->suballoc_offset;
  
  	return cmdbuf;
  
  out_free_cmdbuf:
  	kfree(cmdbuf);
  	return NULL;
  }
  
  void etnaviv_cmdbuf_free(struct etnaviv_cmdbuf *cmdbuf)
  {
  	struct etnaviv_cmdbuf_suballoc *suballoc = cmdbuf->suballoc;
  	int order = order_base_2(ALIGN(cmdbuf->size, SUBALLOC_GRANULE) /
  				 SUBALLOC_GRANULE);
  
  	mutex_lock(&suballoc->lock);
  	bitmap_release_region(suballoc->granule_map,
  			      cmdbuf->suballoc_offset / SUBALLOC_GRANULE,
  			      order);
  	suballoc->free_space = 1;
  	mutex_unlock(&suballoc->lock);
  	wake_up_all(&suballoc->free_event);
  	kfree(cmdbuf->pmrs);
  	kfree(cmdbuf);
  }
  
  u32 etnaviv_cmdbuf_get_va(struct etnaviv_cmdbuf *buf)
  {
  	return buf->suballoc->iova + buf->suballoc_offset;
  }
  
  dma_addr_t etnaviv_cmdbuf_get_pa(struct etnaviv_cmdbuf *buf)
  {
  	return buf->suballoc->paddr + buf->suballoc_offset;
  }
  