drivers/gpu/drm/ttm/ttm_bo_vm.c - maze/linux - Git at Google

 /**************************************************************************
  *
  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
  * 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 above copyright notice and this permission notice (including the
  * next paragraph) shall be included in all copies or substantial portions
  * of the Software.
  *
  * 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.
  *
  **************************************************************************/
 /*
  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
  */

 #define pr_fmt(fmt) "[TTM] " fmt

 #include <ttm/ttm_module.h>
 #include <ttm/ttm_bo_driver.h>
 #include <ttm/ttm_placement.h>
 #include <drm/drm_vma_manager.h>
 #include <linux/mm.h>
 #include <linux/rbtree.h>
 #include <linux/module.h>
 #include <linux/uaccess.h>

 #define TTM_BO_VM_NUM_PREFAULT 16

 static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
 				struct vm_area_struct *vma,
 				struct vm_fault *vmf)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
 	int ret = 0;

 	spin_lock(&bdev->fence_lock);
 	if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
 		goto out_unlock;

 	/*
 	 * Quick non-stalling check for idle.
 	 */
 	ret = ttm_bo_wait(bo, false, false, true);
 	if (likely(ret == 0))
 		goto out_unlock;

 	/*
 	 * If possible, avoid waiting for GPU with mmap_sem
 	 * held.
 	 */
 	if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
 		ret = VM_FAULT_RETRY;
 		if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
 			goto out_unlock;

 		up_read(&vma->vm_mm->mmap_sem);
 		(void) ttm_bo_wait(bo, false, true, false);
 		goto out_unlock;
 	}

 	/*
 	 * Ordinary wait.
 	 */
 	ret = ttm_bo_wait(bo, false, true, false);
 	if (unlikely(ret != 0))
 		ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
 			VM_FAULT_NOPAGE;

 out_unlock:
 	spin_unlock(&bdev->fence_lock);
 	return ret;
 }

 static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
 	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)
 	    vma->vm_private_data;
 	struct ttm_bo_device *bdev = bo->bdev;
 	unsigned long page_offset;
 	unsigned long page_last;
 	unsigned long pfn;
 	struct ttm_tt *ttm = NULL;
 	struct page *page;
 	int ret;
 	int i;
 	unsigned long address = (unsigned long)vmf->virtual_address;
 	int retval = VM_FAULT_NOPAGE;
 	struct ttm_mem_type_manager *man =
 		&bdev->man[bo->mem.mem_type];
 	struct vm_area_struct cvma;

 	/*
 	 * Work around locking order reversal in fault / nopfn
 	 * between mmap_sem and bo_reserve: Perform a trylock operation
 	 * for reserve, and if it fails, retry the fault after waiting
 	 * for the buffer to become unreserved.
 	 */
 	ret = ttm_bo_reserve(bo, true, true, false, NULL);
 	if (unlikely(ret != 0)) {
 		if (ret != -EBUSY)
 			return VM_FAULT_NOPAGE;

 		if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
 			if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
 				up_read(&vma->vm_mm->mmap_sem);
 				(void) ttm_bo_wait_unreserved(bo);
 			}

 			return VM_FAULT_RETRY;
 		}

 		/*
 		 * If we'd want to change locking order to
 		 * mmap_sem -> bo::reserve, we'd use a blocking reserve here
 		 * instead of retrying the fault...
 		 */
 		return VM_FAULT_NOPAGE;
 	}

 	if (bdev->driver->fault_reserve_notify) {
 		ret = bdev->driver->fault_reserve_notify(bo);
 		switch (ret) {
 		case 0:
 			break;
 		case -EBUSY:
 		case -ERESTARTSYS:
 			retval = VM_FAULT_NOPAGE;
 			goto out_unlock;
 		default:
 			retval = VM_FAULT_SIGBUS;
 			goto out_unlock;
 		}
 	}

 	/*
 	 * Wait for buffer data in transit, due to a pipelined
 	 * move.
 	 */
 	ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
 	if (unlikely(ret != 0)) {
 		retval = ret;
 		goto out_unlock;
 	}

 	ret = ttm_mem_io_lock(man, true);
 	if (unlikely(ret != 0)) {
 		retval = VM_FAULT_NOPAGE;
 		goto out_unlock;
 	}
 	ret = ttm_mem_io_reserve_vm(bo);
 	if (unlikely(ret != 0)) {
 		retval = VM_FAULT_SIGBUS;
 		goto out_io_unlock;
 	}

 	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
 	    drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
 	page_last = vma_pages(vma) +
 	    drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;

 	if (unlikely(page_offset >= bo->num_pages)) {
 		retval = VM_FAULT_SIGBUS;
 		goto out_io_unlock;
 	}

 	/*
 	 * Make a local vma copy to modify the page_prot member
 	 * and vm_flags if necessary. The vma parameter is protected
 	 * by mmap_sem in write mode.
 	 */
 	cvma = *vma;
 	cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);

 	if (bo->mem.bus.is_iomem) {
 		cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 						cvma.vm_page_prot);
 	} else {
 		ttm = bo->ttm;
 		if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
 			cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
 							cvma.vm_page_prot);

 		/* Allocate all page at once, most common usage */
 		if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
 			retval = VM_FAULT_OOM;
 			goto out_io_unlock;
 		}
 	}

 	/*
 	 * Speculatively prefault a number of pages. Only error on
 	 * first page.
 	 */
 	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 		if (bo->mem.bus.is_iomem)
 			pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 		else {
 			page = ttm->pages[page_offset];
 			if (unlikely(!page && i == 0)) {
 				retval = VM_FAULT_OOM;
 				goto out_io_unlock;
 			} else if (unlikely(!page)) {
 				break;
 			}
 			pfn = page_to_pfn(page);
 		}

 		ret = vm_insert_mixed(&cvma, address, pfn);
 		/*
 		 * Somebody beat us to this PTE or prefaulting to
 		 * an already populated PTE, or prefaulting error.
 		 */

 		if (unlikely((ret == -EBUSY) || (ret != 0 && i > 0)))
 			break;
 		else if (unlikely(ret != 0)) {
 			retval =
 			    (ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
 			goto out_io_unlock;
 		}

 		address += PAGE_SIZE;
 		if (unlikely(++page_offset >= page_last))
 			break;
 	}
 out_io_unlock:
 	ttm_mem_io_unlock(man);
 out_unlock:
 	ttm_bo_unreserve(bo);
 	return retval;
 }

 static void ttm_bo_vm_open(struct vm_area_struct *vma)
 {
 	struct ttm_buffer_object *bo =
 	    (struct ttm_buffer_object *)vma->vm_private_data;

 	(void)ttm_bo_reference(bo);
 }

 static void ttm_bo_vm_close(struct vm_area_struct *vma)
 {
 	struct ttm_buffer_object *bo = (struct ttm_buffer_object *)vma->vm_private_data;

 	ttm_bo_unref(&bo);
 	vma->vm_private_data = NULL;
 }

 static const struct vm_operations_struct ttm_bo_vm_ops = {
 	.fault = ttm_bo_vm_fault,
 	.open = ttm_bo_vm_open,
 	.close = ttm_bo_vm_close
 };

 static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
 						  unsigned long offset,
 						  unsigned long pages)
 {
 	struct drm_vma_offset_node *node;
 	struct ttm_buffer_object *bo = NULL;

 	drm_vma_offset_lock_lookup(&bdev->vma_manager);

 	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
 	if (likely(node)) {
 		bo = container_of(node, struct ttm_buffer_object, vma_node);
 		if (!kref_get_unless_zero(&bo->kref))
 			bo = NULL;
 	}

 	drm_vma_offset_unlock_lookup(&bdev->vma_manager);

 	if (!bo)
 		pr_err("Could not find buffer object to map\n");

 	return bo;
 }

 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 		struct ttm_bo_device *bdev)
 {
 	struct ttm_bo_driver *driver;
 	struct ttm_buffer_object *bo;
 	int ret;

 	bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
 	if (unlikely(!bo))
 		return -EINVAL;

 	driver = bo->bdev->driver;
 	if (unlikely(!driver->verify_access)) {
 		ret = -EPERM;
 		goto out_unref;
 	}
 	ret = driver->verify_access(bo, filp);
 	if (unlikely(ret != 0))
 		goto out_unref;

 	vma->vm_ops = &ttm_bo_vm_ops;

 	/*
 	 * Note: We're transferring the bo reference to
 	 * vma->vm_private_data here.
 	 */

 	vma->vm_private_data = bo;
 	vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
 	return 0;
 out_unref:
 	ttm_bo_unref(&bo);
 	return ret;
 }
 EXPORT_SYMBOL(ttm_bo_mmap);

 int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
 {
 	if (vma->vm_pgoff != 0)
 		return -EACCES;

 	vma->vm_ops = &ttm_bo_vm_ops;
 	vma->vm_private_data = ttm_bo_reference(bo);
 	vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
 	return 0;
 }
 EXPORT_SYMBOL(ttm_fbdev_mmap);
	/**************************************************************************
	*
	* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
	* 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 above copyright notice and this permission notice (including the
	* next paragraph) shall be included in all copies or substantial portions
	* of the Software.
	*
	* 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.
	*
	**************************************************************************/
	/*
	* Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
	*/

	#define pr_fmt(fmt) "[TTM] " fmt

	#include <ttm/ttm_module.h>
	#include <ttm/ttm_bo_driver.h>
	#include <ttm/ttm_placement.h>
	#include <drm/drm_vma_manager.h>
	#include <linux/mm.h>
	#include <linux/rbtree.h>
	#include <linux/module.h>
	#include <linux/uaccess.h>

	#define TTM_BO_VM_NUM_PREFAULT 16

	static int ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
	struct vm_area_struct *vma,
	struct vm_fault *vmf)
	{
	struct ttm_bo_device *bdev = bo->bdev;
	int ret = 0;

	spin_lock(&bdev->fence_lock);
	if (likely(!test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)))
	goto out_unlock;

	/*
	* Quick non-stalling check for idle.
	*/
	ret = ttm_bo_wait(bo, false, false, true);
	if (likely(ret == 0))
	goto out_unlock;

	/*
	* If possible, avoid waiting for GPU with mmap_sem
	* held.
	*/
	if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
	ret = VM_FAULT_RETRY;
	if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
	goto out_unlock;

	up_read(&vma->vm_mm->mmap_sem);
	(void) ttm_bo_wait(bo, false, true, false);
	goto out_unlock;
	}

	/*
	* Ordinary wait.
	*/
	ret = ttm_bo_wait(bo, false, true, false);
	if (unlikely(ret != 0))
	ret = (ret != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
	VM_FAULT_NOPAGE;

	out_unlock:
	spin_unlock(&bdev->fence_lock);
	return ret;
	}

	static int ttm_bo_vm_fault(struct vm_area_struct vma, struct vm_fault vmf)
	{
	struct ttm_buffer_object bo = (struct ttm_buffer_object )
	vma->vm_private_data;
	struct ttm_bo_device *bdev = bo->bdev;
	unsigned long page_offset;
	unsigned long page_last;
	unsigned long pfn;
	struct ttm_tt *ttm = NULL;
	struct page *page;
	int ret;
	int i;
	unsigned long address = (unsigned long)vmf->virtual_address;
	int retval = VM_FAULT_NOPAGE;
	struct ttm_mem_type_manager *man =
	&bdev->man[bo->mem.mem_type];
	struct vm_area_struct cvma;

	/*
	* Work around locking order reversal in fault / nopfn
	* between mmap_sem and bo_reserve: Perform a trylock operation
	* for reserve, and if it fails, retry the fault after waiting
	* for the buffer to become unreserved.
	*/
	ret = ttm_bo_reserve(bo, true, true, false, NULL);
	if (unlikely(ret != 0)) {
	if (ret != -EBUSY)
	return VM_FAULT_NOPAGE;

	if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
	if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
	up_read(&vma->vm_mm->mmap_sem);
	(void) ttm_bo_wait_unreserved(bo);
	}

	return VM_FAULT_RETRY;
	}

	/*
	* If we'd want to change locking order to
	* mmap_sem -> bo::reserve, we'd use a blocking reserve here
	* instead of retrying the fault...
	*/
	return VM_FAULT_NOPAGE;
	}

	if (bdev->driver->fault_reserve_notify) {
	ret = bdev->driver->fault_reserve_notify(bo);
	switch (ret) {
	case 0:
	break;
	case -EBUSY:
	case -ERESTARTSYS:
	retval = VM_FAULT_NOPAGE;
	goto out_unlock;
	default:
	retval = VM_FAULT_SIGBUS;
	goto out_unlock;
	}
	}

	/*
	* Wait for buffer data in transit, due to a pipelined
	* move.
	*/
	ret = ttm_bo_vm_fault_idle(bo, vma, vmf);
	if (unlikely(ret != 0)) {
	retval = ret;
	goto out_unlock;
	}

	ret = ttm_mem_io_lock(man, true);
	if (unlikely(ret != 0)) {
	retval = VM_FAULT_NOPAGE;
	goto out_unlock;
	}
	ret = ttm_mem_io_reserve_vm(bo);
	if (unlikely(ret != 0)) {
	retval = VM_FAULT_SIGBUS;
	goto out_io_unlock;
	}

	page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
	drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;
	page_last = vma_pages(vma) +
	drm_vma_node_start(&bo->vma_node) - vma->vm_pgoff;

	if (unlikely(page_offset >= bo->num_pages)) {
	retval = VM_FAULT_SIGBUS;
	goto out_io_unlock;
	}

	/*
	* Make a local vma copy to modify the page_prot member
	* and vm_flags if necessary. The vma parameter is protected
	* by mmap_sem in write mode.
	*/
	cvma = *vma;
	cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags);

	if (bo->mem.bus.is_iomem) {
	cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
	cvma.vm_page_prot);
	} else {
	ttm = bo->ttm;
	if (!(bo->mem.placement & TTM_PL_FLAG_CACHED))
	cvma.vm_page_prot = ttm_io_prot(bo->mem.placement,
	cvma.vm_page_prot);

	/* Allocate all page at once, most common usage */
	if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
	retval = VM_FAULT_OOM;
	goto out_io_unlock;
	}
	}

	/*
	* Speculatively prefault a number of pages. Only error on
	* first page.
	*/
	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
	if (bo->mem.bus.is_iomem)
	pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
	else {
	page = ttm->pages[page_offset];
	if (unlikely(!page && i == 0)) {
	retval = VM_FAULT_OOM;
	goto out_io_unlock;
	} else if (unlikely(!page)) {
	break;
	}
	pfn = page_to_pfn(page);
	}

	ret = vm_insert_mixed(&cvma, address, pfn);
	/*
	* Somebody beat us to this PTE or prefaulting to
	* an already populated PTE, or prefaulting error.
	*/

	if (unlikely((ret == -EBUSY) \|\| (ret != 0 && i > 0)))
	break;
	else if (unlikely(ret != 0)) {
	retval =
	(ret == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS;
	goto out_io_unlock;
	}

	address += PAGE_SIZE;
	if (unlikely(++page_offset >= page_last))
	break;
	}
	out_io_unlock:
	ttm_mem_io_unlock(man);
	out_unlock:
	ttm_bo_unreserve(bo);
	return retval;
	}

	static void ttm_bo_vm_open(struct vm_area_struct *vma)
	{
	struct ttm_buffer_object *bo =
	(struct ttm_buffer_object *)vma->vm_private_data;

	(void)ttm_bo_reference(bo);
	}

	static void ttm_bo_vm_close(struct vm_area_struct *vma)
	{
	struct ttm_buffer_object bo = (struct ttm_buffer_object )vma->vm_private_data;

	ttm_bo_unref(&bo);
	vma->vm_private_data = NULL;
	}

	static const struct vm_operations_struct ttm_bo_vm_ops = {
	.fault = ttm_bo_vm_fault,
	.open = ttm_bo_vm_open,
	.close = ttm_bo_vm_close
	};

	static struct ttm_buffer_object ttm_bo_vm_lookup(struct ttm_bo_device bdev,
	unsigned long offset,
	unsigned long pages)
	{
	struct drm_vma_offset_node *node;
	struct ttm_buffer_object *bo = NULL;

	drm_vma_offset_lock_lookup(&bdev->vma_manager);

	node = drm_vma_offset_lookup_locked(&bdev->vma_manager, offset, pages);
	if (likely(node)) {
	bo = container_of(node, struct ttm_buffer_object, vma_node);
	if (!kref_get_unless_zero(&bo->kref))
	bo = NULL;
	}

	drm_vma_offset_unlock_lookup(&bdev->vma_manager);

	if (!bo)
	pr_err("Could not find buffer object to map\n");

	return bo;
	}

	int ttm_bo_mmap(struct file filp, struct vm_area_struct vma,
	struct ttm_bo_device *bdev)
	{
	struct ttm_bo_driver *driver;
	struct ttm_buffer_object *bo;
	int ret;

	bo = ttm_bo_vm_lookup(bdev, vma->vm_pgoff, vma_pages(vma));
	if (unlikely(!bo))
	return -EINVAL;

	driver = bo->bdev->driver;
	if (unlikely(!driver->verify_access)) {
	ret = -EPERM;
	goto out_unref;
	}
	ret = driver->verify_access(bo, filp);
	if (unlikely(ret != 0))
	goto out_unref;

	vma->vm_ops = &ttm_bo_vm_ops;

	/*
	* Note: We're transferring the bo reference to
	* vma->vm_private_data here.
	*/

	vma->vm_private_data = bo;
	vma->vm_flags \|= VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND \| VM_DONTDUMP;
	return 0;
	out_unref:
	ttm_bo_unref(&bo);
	return ret;
	}
	EXPORT_SYMBOL(ttm_bo_mmap);

	int ttm_fbdev_mmap(struct vm_area_struct vma, struct ttm_buffer_object bo)
	{
	if (vma->vm_pgoff != 0)
	return -EACCES;

	vma->vm_ops = &ttm_bo_vm_ops;
	vma->vm_private_data = ttm_bo_reference(bo);
	vma->vm_flags \|= VM_IO \| VM_MIXEDMAP \| VM_DONTEXPAND;
	return 0;
	}
	EXPORT_SYMBOL(ttm_fbdev_mmap);