text: /*
   * Copyright (C) Christian König.
   * All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sub license, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
   * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
   * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
   * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
   * USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   * The above copyright notice and this permission notice (including the
   * next paragraph) shall be included in all copies or substantial portions
   * of the Software.
   *
   */
  /*
   * Authors:
   *    Christian König <deathsimple@vodafone.de>
   */
  #include "drmP.h"
  #include "drm.h"
  #include "radeon.h"
  
  static int radeon_semaphore_add_bo(struct radeon_device *rdev)
  {
  	struct radeon_semaphore_bo *bo;
  	unsigned long irq_flags;
  	uint64_t gpu_addr;
  	uint32_t *cpu_ptr;
  	int r, i;
  
  
  	bo = kmalloc(sizeof(struct radeon_semaphore_bo), GFP_KERNEL);
  	if (bo == NULL) {
  		return -ENOMEM;
  	}
  	INIT_LIST_HEAD(&bo->free);
  	INIT_LIST_HEAD(&bo->list);
  	bo->nused = 0;
  
  	r = radeon_ib_get(rdev, 0, &bo->ib, RADEON_SEMAPHORE_BO_SIZE);
  	if (r) {
  		dev_err(rdev->dev, "failed to get a bo after 5 retry\n");
  		kfree(bo);
  		return r;
  	}
  	gpu_addr = rdev->ib_pool.sa_manager.gpu_addr;
  	gpu_addr += bo->ib->sa_bo.offset;
  	cpu_ptr = rdev->ib_pool.sa_manager.cpu_ptr;
  	cpu_ptr += (bo->ib->sa_bo.offset >> 2);
  	for (i = 0; i < (RADEON_SEMAPHORE_BO_SIZE/8); i++) {
  		bo->semaphores[i].gpu_addr = gpu_addr;
  		bo->semaphores[i].cpu_ptr = cpu_ptr;
  		bo->semaphores[i].bo = bo;
  		list_add_tail(&bo->semaphores[i].list, &bo->free);
  		gpu_addr += 8;
  		cpu_ptr += 2;
  	}
  	write_lock_irqsave(&rdev->semaphore_drv.lock, irq_flags);
  	list_add_tail(&bo->list, &rdev->semaphore_drv.bo);
  	write_unlock_irqrestore(&rdev->semaphore_drv.lock, irq_flags);
  	return 0;
  }
  
  static void radeon_semaphore_del_bo_locked(struct radeon_device *rdev,
  					   struct radeon_semaphore_bo *bo)
  {
  	radeon_sa_bo_free(rdev, &bo->ib->sa_bo);
  	radeon_fence_unref(&bo->ib->fence);
  	list_del(&bo->list);
  	kfree(bo);
  }
  
  void radeon_semaphore_shrink_locked(struct radeon_device *rdev)
  {
  	struct radeon_semaphore_bo *bo, *n;
  
  	if (list_empty(&rdev->semaphore_drv.bo)) {
  		return;
  	}
  	/* only shrink if first bo has free semaphore */
  	bo = list_first_entry(&rdev->semaphore_drv.bo, struct radeon_semaphore_bo, list);
  	if (list_empty(&bo->free)) {
  		return;
  	}
  	list_for_each_entry_safe_continue(bo, n, &rdev->semaphore_drv.bo, list) {
  		if (bo->nused)
  			continue;
  		radeon_semaphore_del_bo_locked(rdev, bo);
  	}
  }
  
  int radeon_semaphore_create(struct radeon_device *rdev,
  			    struct radeon_semaphore **semaphore)
  {
  	struct radeon_semaphore_bo *bo;
  	unsigned long irq_flags;
  	bool do_retry = true;
  	int r;
  
  retry:
  	*semaphore = NULL;
  	write_lock_irqsave(&rdev->semaphore_drv.lock, irq_flags);
  	list_for_each_entry(bo, &rdev->semaphore_drv.bo, list) {
  		if (list_empty(&bo->free))
  			continue;
  		*semaphore = list_first_entry(&bo->free, struct radeon_semaphore, list);
  		(*semaphore)->cpu_ptr[0] = 0;
  		(*semaphore)->cpu_ptr[1] = 0;
  		list_del(&(*semaphore)->list);
  		bo->nused++;
  		break;
  	}
  	write_unlock_irqrestore(&rdev->semaphore_drv.lock, irq_flags);
  
  	if (*semaphore == NULL) {
  		if (do_retry) {
  			do_retry = false;
  			r = radeon_semaphore_add_bo(rdev);
  			if (r)
  				return r;
  			goto retry;
  		}
  		return -ENOMEM;
  	}
  
  	return 0;
  }
  
  void radeon_semaphore_emit_signal(struct radeon_device *rdev, int ring,
  			          struct radeon_semaphore *semaphore)
  {
  	radeon_semaphore_ring_emit(rdev, ring, &rdev->ring[ring], semaphore, false);
  }
  
  void radeon_semaphore_emit_wait(struct radeon_device *rdev, int ring,
  			        struct radeon_semaphore *semaphore)
  {
  	radeon_semaphore_ring_emit(rdev, ring, &rdev->ring[ring], semaphore, true);
  }
  
  void radeon_semaphore_free(struct radeon_device *rdev,
  			   struct radeon_semaphore *semaphore)
  {
  	unsigned long irq_flags;
  
  	write_lock_irqsave(&rdev->semaphore_drv.lock, irq_flags);
  	semaphore->bo->nused--;
  	list_add_tail(&semaphore->list, &semaphore->bo->free);
  	radeon_semaphore_shrink_locked(rdev);
  	write_unlock_irqrestore(&rdev->semaphore_drv.lock, irq_flags);
  }
  
  void radeon_semaphore_driver_fini(struct radeon_device *rdev)
  {
  	struct radeon_semaphore_bo *bo, *n;
  	unsigned long irq_flags;
  
  	write_lock_irqsave(&rdev->semaphore_drv.lock, irq_flags);
  	/* we force to free everything */
  	list_for_each_entry_safe(bo, n, &rdev->semaphore_drv.bo, list) {
  		if (!list_empty(&bo->free)) {
  			dev_err(rdev->dev, "still in use semaphore\n");
  		}
  		radeon_semaphore_del_bo_locked(rdev, bo);
  	}
  	write_unlock_irqrestore(&rdev->semaphore_drv.lock, irq_flags);
  }
  