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/* 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. We only do this if the fault allows retry and this
* is the first attempt.
*/
if (fault_flag_allow_retry_first(vmf->flags)) {
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 the fault allows retry and this is the first
* fault attempt, we try to release the mmap_sem
* before waiting
*/
if (fault_flag_allow_retry_first(vmf->flags)) {
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);
/**
* 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.
*
* 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)
{
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);
}
/*
* Speculatively prefault a number of pages. Only error on
* first page.
*/
for (i = 0; i < num_prefaul
|