blob: 0871c7d6cb8cae885324099a2a29f02757efac9e [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/**************************************************************************
*
* 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 <drm/ttm/ttm_module.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
#include <drm/drm_vma_manager.h>
#include <linux/mm.h>
#include <linux/pfn_t.h>
#include <linux/rbtree.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/mem_encrypt.h>
static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo,
struct vm_fault *vmf)
{
vm_fault_t ret = 0;
int err = 0;
if (likely(!bo->moving))
goto out_unlock;
/*
* Quick non-stalling check for idle.
*/
if (dma_fence_is_signaled(bo->moving))
goto out_clear;
/*
* 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;
ttm_bo_get(bo);
up_read(&vmf->vma->vm_mm->mmap_sem);
(void) dma_fence_wait(bo->moving, true);
dma_resv_unlock(bo->base.resv);
ttm_bo_put(bo);
goto out_unlock;
}
/*
* Ordinary wait.
*/
err = dma_fence_wait(bo->moving, true);
if (unlikely(err != 0)) {
ret = (err != -ERESTARTSYS) ? VM_FAULT_SIGBUS :
VM_FAULT_NOPAGE;
goto out_unlock;
}
out_clear:
dma_fence_put(bo->moving);
bo->moving = NULL;
out_unlock:
return ret;
}
static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo,
unsigned long page_offset)
{
struct ttm_bo_device *bdev = bo->bdev;
if (bdev->driver->io_mem_pfn)
return bdev->driver->io_mem_pfn(bo, page_offset);
return ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT)
+ page_offset;
}
/**
* ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback
* @bo: The buffer object
* @vmf: The fault structure handed to the callback
*
* vm callbacks like fault() and *_mkwrite() allow for the mm_sem to be dropped
* during long waits, and after the wait the callback will be restarted. This
* is to allow other threads using the same virtual memory space concurrent
* access to map(), unmap() completely unrelated buffer objects. TTM buffer
* object reservations sometimes wait for GPU and should therefore be
* considered long waits. This function reserves the buffer object interruptibly
* taking this into account. Starvation is avoided by the vm system not
* allowing too many repeated restarts.
* This function is intended to be used in customized fault() and _mkwrite()
* handlers.
*
* Return:
* 0 on success and the bo was reserved.
* VM_FAULT_RETRY if blocking wait.
* VM_FAULT_NOPAGE if blocking wait and retrying was not allowed.
*/
vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo,
struct vm_fault *vmf)
{
/*
* 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.
*/
if (unlikely(!dma_resv_trylock(bo->base.resv))) {
if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) {
if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
ttm_bo_get(bo);
up_read(&vmf->vma->vm_mm->mmap_sem);
if (!dma_resv_lock_interruptible(bo->base.resv,
NULL))
dma_resv_unlock(bo->base.resv);
ttm_bo_put(bo);
}
return VM_FAULT_RETRY;
}
if (dma_resv_lock_interruptible(bo->base.resv, NULL))
return VM_FAULT_NOPAGE;
}
return 0;
}
EXPORT_SYMBOL(ttm_bo_vm_reserve);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/**
* ttm_bo_vm_insert_huge - Insert a pfn for PUD or PMD faults
* @vmf: Fault data
* @bo: The buffer object
* @page_offset: Page offset from bo start
* @fault_page_size: The size of the fault in pages.
* @pgprot: The page protections.
* Does additional checking whether it's possible to insert a PUD or PMD
* pfn and performs the insertion.
*
* Return: VM_FAULT_NOPAGE on successful insertion, VM_FAULT_FALLBACK if
* a huge fault was not possible, or on insertion error.
*/
static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf,
struct ttm_buffer_object *bo,
pgoff_t page_offset,
pgoff_t fault_page_size,
pgprot_t pgprot)
{
pgoff_t i;
vm_fault_t ret;
unsigned long pfn;
pfn_t pfnt;
struct ttm_tt *ttm = bo->ttm;
bool write = vmf->flags & FAULT_FLAG_WRITE;
/* Fault should not cross bo boundary. */
page_offset &= ~(fault_page_size - 1);
if (page_offset + fault_page_size > bo->num_pages)
goto out_fallback;
if (bo->mem.bus.is_iomem)
pfn = ttm_bo_io_mem_pfn(bo, page_offset);
else
pfn = page_to_pfn(ttm->pages[page_offset]);
/* pfn must be fault_page_size aligned. */
if ((pfn & (fault_page_size - 1)) != 0)
goto out_fallback;
/* Check that memory is contiguous. */
if (!bo->mem.bus.is_iomem) {
for (i = 1; i < fault_page_size; ++i) {
if (page_to_pfn(ttm->pages[page_offset + i]) != pfn + i)
goto out_fallback;
}
} else if (bo->bdev->driver->io_mem_pfn) {
for (i = 1; i < fault_page_size; ++i) {
if (ttm_bo_io_mem_pfn(bo, page_offset + i) != pfn + i)
goto out_fallback;
}
}
pfnt = __pfn_to_pfn_t(pfn, PFN_DEV);
if (fault_page_size == (HPAGE_PMD_SIZE >> PAGE_SHIFT))
ret = vmf_insert_pfn_pmd_prot(vmf, pfnt, pgprot, write);
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
else if (fault_page_size == (HPAGE_PUD_SIZE >> PAGE_SHIFT))
ret = vmf_insert_pfn_pud_prot(vmf, pfnt, pgprot, write);
#endif
else
WARN_ON_ONCE(ret = VM_FAULT_FALLBACK);
if (ret != VM_FAULT_NOPAGE)
goto out_fallback;
return VM_FAULT_NOPAGE;
out_fallback:
count_vm_event(THP_FAULT_FALLBACK);
return VM_FAULT_FALLBACK;
}
#else
static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf,
struct ttm_buffer_object *bo,
pgoff_t page_offset,
pgoff_t fault_page_size,
pgprot_t pgprot)
{
return VM_FAULT_FALLBACK;
}
#endif
/**
* ttm_bo_vm_fault_reserved - TTM fault helper
* @vmf: The struct vm_fault given as argument to the fault callback
* @prot: The page protection to be used for this memory area.
* @num_prefault: Maximum number of prefault pages. The caller may want to
* specify this based on madvice settings and the size of the GPU object
* backed by the memory.
* @fault_page_size: The size of the fault in pages.
*
* This function inserts one or more page table entries pointing to the
* memory backing the buffer object, and then returns a return code
* instructing the caller to retry the page access.
*
* Return:
* VM_FAULT_NOPAGE on success or pending signal
* VM_FAULT_SIGBUS on unspecified error
* VM_FAULT_OOM on out-of-memory
* VM_FAULT_RETRY if retryable wait
*/
vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
pgprot_t prot,
pgoff_t num_prefault,
pgoff_t fault_page_size)
{
struct vm_area_struct *vma = vmf->vma;
struct ttm_buffer_object *bo = 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 err;
pgoff_t i;
vm_fault_t ret = VM_FAULT_NOPAGE;
unsigned long address = vmf->address;
struct ttm_mem_type_manager *man =
&bdev->man[bo->mem.mem_type];
/*
* 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))
return VM_FAULT_SIGBUS;
if (bdev->driver->fault_reserve_notify) {
struct dma_fence *moving = dma_fence_get(bo->moving);
err = bdev->driver->fault_reserve_notify(bo);
switch (err) {
case 0:
break;
case -EBUSY:
case -ERESTARTSYS:
return VM_FAULT_NOPAGE;
default:
return VM_FAULT_SIGBUS;
}
if (bo->moving != moving) {
spin_lock(&ttm_bo_glob.lru_lock);
ttm_bo_move_to_lru_tail(bo, NULL);
spin_unlock(&ttm_bo_glob.lru_lock);
}
dma_fence_put(moving);
}
/*
* Wait for buffer data in transit, due to a pipelined
* move.
*/
ret = ttm_bo_vm_fault_idle(bo, vmf);
if (unlikely(ret != 0))
return ret;
err = ttm_mem_io_lock(man, true);
if (unlikely(err != 0))
return VM_FAULT_NOPAGE;
err = ttm_mem_io_reserve_vm(bo);
if (unlikely(err != 0)) {
ret = VM_FAULT_SIGBUS;
goto out_io_unlock;
}
page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) +
vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node);
page_last = vma_pages(vma) + vma->vm_pgoff -
drm_vma_node_start(&bo->base.vma_node);
if (unlikely(page_offset >= bo->num_pages)) {
ret = VM_FAULT_SIGBUS;
goto out_io_unlock;
}
prot = ttm_io_prot(bo->mem.placement, prot);
if (!bo->mem.bus.is_iomem) {
struct ttm_operation_ctx ctx = {
.interruptible = false,
.no_wait_gpu = false,
.flags = TTM_OPT_FLAG_FORCE_ALLOC
};
ttm = bo->ttm;
if (ttm_tt_populate(bo->ttm, &ctx)) {
ret = VM_FAULT_OOM;
goto out_io_unlock;
}
} else {
/* Iomem should not be marked encrypted */
prot = pgprot_decrypted(prot);
}
/* We don't prefault on huge faults. Yet. */
if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && fault_page_size != 1) {
ret = ttm_bo_vm_insert_huge(vmf, bo, page_offset,
fault_page_size, prot);
goto out_io_unlock;
}
/*
* Speculatively prefault a number of pages. Only error on
* first page.
*/
for (i = 0; i < num_prefault; ++i) {
if (bo->mem.bus.is_iomem) {
pfn = ttm_bo_io_mem_pfn(bo, page_offset);
} else {
page = ttm->pages[page_offset];
if (unlikely(!page && i == 0)) {
ret = VM_FAULT_OOM;
goto out_io_unlock;
} else if (unlikely(!page)) {
break;
}
page->index = drm_vma_node_start(&bo->base.vma_node) +
page_offset;
pfn = page_to_pfn(page);
}
/*
* Note that the value of @prot at this point may differ from
* the value of @vma->vm_page_prot in the caching- and
* encryption bits. This is because the exact location of the
* data may not be known at mmap() time and may also change
* at arbitrary times while the data is mmap'ed.
* See vmf_insert_mixed_prot() for a discussion.
*/
if (vma->vm_flags & VM_MIXEDMAP)
ret = vmf_insert_mixed_prot(vma, address,
__pfn_to_pfn_t(pfn, PFN_DEV),
prot);
else
ret = vmf_insert_pfn_prot(vma, address, pfn, prot);
/* Never error on prefaulted PTEs */
if (unlikely((ret & VM_FAULT_ERROR))) {
if (i == 0)
goto out_io_unlock;
else
break;
}
address += PAGE_SIZE;
if (unlikely(++page_offset >= page_last))
break;
}
ret = VM_FAULT_NOPAGE;
out_io_unlock:
ttm_mem_io_unlock(man);
return ret;
}
EXPORT_SYMBOL(ttm_bo_vm_fault_reserved);
vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
pgprot_t prot;
struct ttm_buffer_object *bo = vma->vm_private_data;
vm_fault_t ret;
ret = ttm_bo_vm_reserve(bo, vmf);
if (ret)
return ret;
prot = vma->vm_page_prot;
ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1);
if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
return ret;
dma_resv_unlock(bo->base.resv);
return ret;
}
EXPORT_SYMBOL(ttm_bo_vm_fault);
void ttm_bo_vm_open(struct vm_area_struct *vma)
{
struct ttm_buffer_object *bo = vma->vm_private_data;
WARN_ON(bo->bdev->dev_mapping != vma->vm_file->f_mapping);
ttm_bo_get(bo);
}
EXPORT_SYMBOL(ttm_bo_vm_open);
void ttm_bo_vm_close(struct vm_area_struct *vma)
{
struct ttm_buffer_object *bo = vma->vm_private_data;
ttm_bo_put(bo);
vma->vm_private_data = NULL;
}
EXPORT_SYMBOL(ttm_bo_vm_close);
static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
unsigned long offset,
uint8_t *buf, int len, int write)
{
unsigned long page = offset >> PAGE_SHIFT;
unsigned long bytes_left = len;
int ret;
/* Copy a page at a time, that way no extra virtual address
* mapping is needed
*/
offset -= page << PAGE_SHIFT;
do {
unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
struct ttm_bo_kmap_obj map;
void *ptr;
bool is_iomem;
ret = ttm_bo_kmap(bo, page, 1, &map);
if (ret)
return ret;
ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
WARN_ON_ONCE(is_iomem);
if (write)
memcpy(ptr, buf, bytes);
else
memcpy(buf, ptr, bytes);
ttm_bo_kunmap(&map);
page++;
buf += bytes;
bytes_left -= bytes;
offset = 0;
} while (bytes_left);
return len;
}
int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
void *buf, int len, int write)
{
unsigned long offset = (addr) - vma->vm_start;
struct ttm_buffer_object *bo = vma->vm_private_data;
int ret;
if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
return -EIO;
ret = ttm_bo_reserve(bo, true, false, NULL);
if (ret)
return ret;
switch (bo->mem.mem_type) {
case TTM_PL_SYSTEM:
if (unlikely(bo->ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(bo->ttm);
if (unlikely(ret != 0))
return ret;
}
/* fall through */
case TTM_PL_TT:
ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
break;
default:
if (bo->bdev->driver->access_memory)
ret = bo->bdev->driver->access_memory(
bo, offset, buf, len, write);
else
ret = -EIO;
}
ttm_bo_unreserve(bo);
return ret;
}
EXPORT_SYMBOL(ttm_bo_vm_access);
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,
.access = ttm_bo_vm_access,
};
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,
base.vma_node);
bo = ttm_bo_get_unless_zero(bo);
}
drm_vma_offset_unlock_lookup(bdev->vma_manager);
if (!bo)
pr_err("Could not find buffer object to map\n");
return bo;
}
static void ttm_bo_mmap_vma_setup(struct ttm_buffer_object *bo, struct vm_area_struct *vma)
{
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;
}
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;
if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET_START))
return -EINVAL;
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;
ttm_bo_mmap_vma_setup(bo, vma);
return 0;
out_unref:
ttm_bo_put(bo);
return ret;
}
EXPORT_SYMBOL(ttm_bo_mmap);
int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo)
{
ttm_bo_get(bo);
ttm_bo_mmap_vma_setup(bo, vma);
return 0;
}
EXPORT_SYMBOL(ttm_bo_mmap_obj);