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/**************************************************************************
*
* 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>
*/
/*
* Copyright (c) 2013 The FreeBSD Foundation
* All rights reserved.
*
* Portions of this software were developed by Konstantin Belousov
* <kib@FreeBSD.org> under sponsorship from the FreeBSD Foundation.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_vm.h"
#include <dev/drm2/drmP.h>
#include <dev/drm2/ttm/ttm_module.h>
#include <dev/drm2/ttm/ttm_bo_driver.h>
#include <dev/drm2/ttm/ttm_placement.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#define TTM_BO_VM_NUM_PREFAULT 16
RB_GENERATE(ttm_bo_device_buffer_objects, ttm_buffer_object, vm_rb,
ttm_bo_cmp_rb_tree_items);
int
ttm_bo_cmp_rb_tree_items(struct ttm_buffer_object *a,
struct ttm_buffer_object *b)
{
if (a->vm_node->start < b->vm_node->start) {
return (-1);
} else if (a->vm_node->start > b->vm_node->start) {
return (1);
} else {
return (0);
}
}
static struct ttm_buffer_object *ttm_bo_vm_lookup_rb(struct ttm_bo_device *bdev,
unsigned long page_start,
unsigned long num_pages)
{
unsigned long cur_offset;
struct ttm_buffer_object *bo;
struct ttm_buffer_object *best_bo = NULL;
RB_FOREACH(bo, ttm_bo_device_buffer_objects, &bdev->addr_space_rb) {
cur_offset = bo->vm_node->start;
if (page_start >= cur_offset) {
best_bo = bo;
if (page_start == cur_offset)
break;
}
}
if (unlikely(best_bo == NULL))
return NULL;
if (unlikely((best_bo->vm_node->start + best_bo->num_pages) <
(page_start + num_pages)))
return NULL;
return best_bo;
}
static int
ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offset,
int prot, vm_page_t *mres)
{
struct ttm_buffer_object *bo = vm_obj->handle;
struct ttm_bo_device *bdev = bo->bdev;
struct ttm_tt *ttm = NULL;
vm_page_t m, m1, oldm;
int ret;
int retval = VM_PAGER_OK;
struct ttm_mem_type_manager *man =
&bdev->man[bo->mem.mem_type];
vm_object_pip_add(vm_obj, 1);
oldm = *mres;
if (oldm != NULL) {
vm_page_lock(oldm);
vm_page_remove(oldm);
vm_page_unlock(oldm);
*mres = NULL;
} else
oldm = NULL;
retry:
VM_OBJECT_WUNLOCK(vm_obj);
m = NULL;
reserve:
ret = ttm_bo_reserve(bo, false, false, false, 0);
if (unlikely(ret != 0)) {
if (ret == -EBUSY) {
kern_yield(0);
goto reserve;
}
}
if (bdev->driver->fault_reserve_notify) {
ret = bdev->driver->fault_reserve_notify(bo);
switch (ret) {
case 0:
break;
case -EBUSY:
case -ERESTART:
case -EINTR:
kern_yield(0);
goto reserve;
default:
retval = VM_PAGER_ERROR;
goto out_unlock;
}
}
/*
* Wait for buffer data in transit, due to a pipelined
* move.
*/
mtx_lock(&bdev->fence_lock);
if (test_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags)) {
/*
* Here, the behavior differs between Linux and FreeBSD.
*
* On Linux, the wait is interruptible (3rd argument to
* ttm_bo_wait). There must be some mechanism to resume
* page fault handling, once the signal is processed.
*
* On FreeBSD, the wait is uninteruptible. This is not a
* problem as we can't end up with an unkillable process
* here, because the wait will eventually time out.
*
* An example of this situation is the Xorg process
* which uses SIGALRM internally. The signal could
* interrupt the wait, causing the page fault to fail
* and the process to receive SIGSEGV.
*/
ret = ttm_bo_wait(bo, false, false, false);
mtx_unlock(&bdev->fence_lock);
if (unlikely(ret != 0)) {
retval = VM_PAGER_ERROR;
goto out_unlock;
}
} else
mtx_unlock(&bdev->fence_lock);
ret = ttm_mem_io_lock(man, true);
if (unlikely(ret != 0)) {
retval = VM_PAGER_ERROR;
goto out_unlock;
}
ret = ttm_mem_io_reserve_vm(bo);
if (unlikely(ret != 0)) {
retval = VM_PAGER_ERROR;
goto out_io_unlock;
}
/*
* Strictly, we're not allowed to modify vma->vm_page_prot here,
* since the mmap_sem is only held in read mode. However, we
* modify only the caching bits of vma->vm_page_prot and
* consider those bits protected by
* the bo->mutex, as we should be the only writers.
* There shouldn't really be any readers of these bits except
* within vm_insert_mixed()? fork?
*
* TODO: Add a list of vmas to the bo, and change the
* vma->vm_page_prot when the object changes caching policy, with
* the correct locks held.
*/
if (!bo->mem.bus.is_iomem) {
/* Allocate all page at once, most common usage */
ttm = bo->ttm;
if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
retval = VM_PAGER_ERROR;
goto out_io_unlock;
}
}
if (bo->mem.bus.is_iomem) {
m = vm_phys_fictitious_to_vm_page(bo->mem.bus.base +
bo->mem.bus.offset + offset);
pmap_page_set_memattr(m, ttm_io_prot(bo->mem.placement));
} else {
ttm = bo->ttm;
m = ttm->pages[OFF_TO_IDX(offset)];
if (unlikely(!m)) {
retval = VM_PAGER_ERROR;
goto out_io_unlock;
}
pmap_page_set_memattr(m,
(bo->mem.placement & TTM_PL_FLAG_CACHED) ?
VM_MEMATTR_WRITE_BACK : ttm_io_prot(bo->mem.placement));
}
VM_OBJECT_WLOCK(vm_obj);
if (vm_page_busied(m)) {
vm_page_lock(m);
VM_OBJECT_WUNLOCK(vm_obj);
vm_page_busy_sleep(m, "ttmpbs");
VM_OBJECT_WLOCK(vm_obj);
ttm_mem_io_unlock(man);
ttm_bo_unreserve(bo);
goto retry;
}
m1 = vm_page_lookup(vm_obj, OFF_TO_IDX(offset));
if (m1 == NULL) {
if (vm_page_insert(m, vm_obj, OFF_TO_IDX(offset))) {
VM_OBJECT_WUNLOCK(vm_obj);
VM_WAIT;
VM_OBJECT_WLOCK(vm_obj);
ttm_mem_io_unlock(man);
ttm_bo_unreserve(bo);
goto retry;
}
} else {
KASSERT(m == m1,
("inconsistent insert bo %p m %p m1 %p offset %jx",
bo, m, m1, (uintmax_t)offset));
}
m->valid = VM_PAGE_BITS_ALL;
*mres = m;
vm_page_xbusy(m);
if (oldm != NULL) {
vm_page_lock(oldm);
vm_page_free(oldm);
vm_page_unlock(oldm);
}
out_io_unlock1:
ttm_mem_io_unlock(man);
out_unlock1:
ttm_bo_unreserve(bo);
vm_object_pip_wakeup(vm_obj);
return (retval);
out_io_unlock:
VM_OBJECT_WLOCK(vm_obj);
goto out_io_unlock1;
out_unlock:
VM_OBJECT_WLOCK(vm_obj);
goto out_unlock1;
}
static int
ttm_bo_vm_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred, u_short *color)
{
/*
* On Linux, a reference to the buffer object is acquired here.
* The reason is that this function is not called when the
* mmap() is initialized, but only when a process forks for
* instance. Therefore on Linux, the reference on the bo is
* acquired either in ttm_bo_mmap() or ttm_bo_vm_open(). It's
* then released in ttm_bo_vm_close().
*
* Here, this function is called during mmap() intialization.
* Thus, the reference acquired in ttm_bo_mmap_single() is
* sufficient.
*/
*color = 0;
return (0);
}
static void
ttm_bo_vm_dtor(void *handle)
{
struct ttm_buffer_object *bo = handle;
ttm_bo_unref(&bo);
}
static struct cdev_pager_ops ttm_pager_ops = {
.cdev_pg_fault = ttm_bo_vm_fault,
.cdev_pg_ctor = ttm_bo_vm_ctor,
.cdev_pg_dtor = ttm_bo_vm_dtor
};
int
ttm_bo_mmap_single(struct ttm_bo_device *bdev, vm_ooffset_t *offset, vm_size_t size,
struct vm_object **obj_res, int nprot)
{
struct ttm_bo_driver *driver;
struct ttm_buffer_object *bo;
struct vm_object *vm_obj;
int ret;
rw_wlock(&bdev->vm_lock);
bo = ttm_bo_vm_lookup_rb(bdev, OFF_TO_IDX(*offset), OFF_TO_IDX(size));
if (likely(bo != NULL))
refcount_acquire(&bo->kref);
rw_wunlock(&bdev->vm_lock);
if (unlikely(bo == NULL)) {
printf("[TTM] Could not find buffer object to map\n");
return (EINVAL);
}
driver = bo->bdev->driver;
if (unlikely(!driver->verify_access)) {
ret = EPERM;
goto out_unref;
}
ret = -driver->verify_access(bo);
if (unlikely(ret != 0))
goto out_unref;
vm_obj = cdev_pager_allocate(bo, OBJT_MGTDEVICE, &ttm_pager_ops,
size, nprot, 0, curthread->td_ucred);
if (vm_obj == NULL) {
ret = EINVAL;
goto out_unref;
}
/*
* Note: We're transferring the bo reference to vm_obj->handle here.
*/
*offset = 0;
*obj_res = vm_obj;
return 0;
out_unref:
ttm_bo_unref(&bo);
return ret;
}
void
ttm_bo_release_mmap(struct ttm_buffer_object *bo)
{
vm_object_t vm_obj;
vm_page_t m;
int i;
vm_obj = cdev_pager_lookup(bo);
if (vm_obj == NULL)
return;
VM_OBJECT_WLOCK(vm_obj);
retry:
for (i = 0; i < bo->num_pages; i++) {
m = vm_page_lookup(vm_obj, i);
if (m == NULL)
continue;
if (vm_page_sleep_if_busy(m, "ttm_unm"))
goto retry;
cdev_pager_free_page(vm_obj, m);
}
VM_OBJECT_WUNLOCK(vm_obj);
vm_object_deallocate(vm_obj);
}
#if 0
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;
}
ssize_t ttm_bo_io(struct ttm_bo_device *bdev, struct file *filp,
const char __user *wbuf, char __user *rbuf, size_t count,
loff_t *f_pos, bool write)
{
struct ttm_buffer_object *bo;
struct ttm_bo_driver *driver;
struct ttm_bo_kmap_obj map;
unsigned long dev_offset = (*f_pos >> PAGE_SHIFT);
unsigned long kmap_offset;
unsigned long kmap_end;
unsigned long kmap_num;
size_t io_size;
unsigned int page_offset;
char *virtual;
int ret;
bool no_wait = false;
bool dummy;
read_lock(&bdev->vm_lock);
bo = ttm_bo_vm_lookup_rb(bdev, dev_offset, 1);
if (likely(bo != NULL))
ttm_bo_reference(bo);
read_unlock(&bdev->vm_lock);
if (unlikely(bo == NULL))
return -EFAULT;
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;
kmap_offset = dev_offset - bo->vm_node->start;
if (unlikely(kmap_offset >= bo->num_pages)) {
ret = -EFBIG;
goto out_unref;
}
page_offset = *f_pos & ~PAGE_MASK;
io_size = bo->num_pages - kmap_offset;
io_size = (io_size << PAGE_SHIFT) - page_offset;
if (count < io_size)
io_size = count;
kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
kmap_num = kmap_end - kmap_offset + 1;
ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
switch (ret) {
case 0:
break;
case -EBUSY:
ret = -EAGAIN;
goto out_unref;
default:
goto out_unref;
}
ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
if (unlikely(ret != 0)) {
ttm_bo_unreserve(bo);
goto out_unref;
}
virtual = ttm_kmap_obj_virtual(&map, &dummy);
virtual += page_offset;
if (write)
ret = copy_from_user(virtual, wbuf, io_size);
else
ret = copy_to_user(rbuf, virtual, io_size);
ttm_bo_kunmap(&map);
ttm_bo_unreserve(bo);
ttm_bo_unref(&bo);
if (unlikely(ret != 0))
return -EFBIG;
*f_pos += io_size;
return io_size;
out_unref:
ttm_bo_unref(&bo);
return ret;
}
ssize_t ttm_bo_fbdev_io(struct ttm_buffer_object *bo, const char __user *wbuf,
char __user *rbuf, size_t count, loff_t *f_pos,
bool write)
{
struct ttm_bo_kmap_obj map;
unsigned long kmap_offset;
unsigned long kmap_end;
unsigned long kmap_num;
size_t io_size;
unsigned int page_offset;
char *virtual;
int ret;
bool no_wait = false;
bool dummy;
kmap_offset = (*f_pos >> PAGE_SHIFT);
if (unlikely(kmap_offset >= bo->num_pages))
return -EFBIG;
page_offset = *f_pos & ~PAGE_MASK;
io_size = bo->num_pages - kmap_offset;
io_size = (io_size << PAGE_SHIFT) - page_offset;
if (count < io_size)
io_size = count;
kmap_end = (*f_pos + count - 1) >> PAGE_SHIFT;
kmap_num = kmap_end - kmap_offset + 1;
ret = ttm_bo_reserve(bo, true, no_wait, false, 0);
switch (ret) {
case 0:
break;
case -EBUSY:
return -EAGAIN;
default:
return ret;
}
ret = ttm_bo_kmap(bo, kmap_offset, kmap_num, &map);
if (unlikely(ret != 0)) {
ttm_bo_unreserve(bo);
return ret;
}
virtual = ttm_kmap_obj_virtual(&map, &dummy);
virtual += page_offset;
if (write)
ret = copy_from_user(virtual, wbuf, io_size);
else
ret = copy_to_user(rbuf, virtual, io_size);
ttm_bo_kunmap(&map);
ttm_bo_unreserve(bo);
ttm_bo_unref(&bo);
if (unlikely(ret != 0))
return ret;
*f_pos += io_size;
return io_size;
}
#endif
|