/**************************************************************************
*
* 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)
{
int ret = 0;
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:
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;
}
/*
* Refuse to fault imported pages. This should be handled
* (if at all) by redirecting mmap to the exporter.
*/
if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) {
retval = VM_FAULT_SIGBUS;
goto out_unlock;
}
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) +
vma->vm_pgoff - drm_vma_node_start(&bo->vma_node);
page_last = vma_pages(vma) + vma->vm_pgoff -
drm_vma_node_start(&bo->vma_node);
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;
}
page->mapping = vma->vm_file->f_mapping;
page->index = drm_vma_node_start(&bo->vma_node) +
page_offset;
pfn = page_to_pfn(page);
}
if (vma->vm_flags & VM_MIXEDMAP)
ret = vm_insert_mixed(&cvma, address, pfn);
else
ret = vm_insert_pfn(&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;
WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
(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;
/*
* We'd like to use VM_PFNMAP on shared mappings, where
* (vma->vm_flags & VM_SHARED) != 0, for performance reasons,
* but for some reason VM_PFNMAP + x86 PAT + write-combine is very
* bad for performance. Until that has been sorted out, use
* VM_MIXEDMAP on all mappings. See freedesktop.org bug #75719
*/
vma->vm_flags |= VM_MIXEDMAP;
vma->vm_flags |= VM_IO | 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_MIXEDMAP;
vma->vm_flags |= VM_IO | VM_DONTEXPAND;
return 0;
}
EXPORT_SYMBOL(ttm_fbdev_mmap);
