cregit-Linux how code gets into the kernel

Release 4.7 drivers/gpu/drm/ttm/ttm_bo_vm.c

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

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thomas hellstromthomas hellstrom159100.00%1100.00%
Total159100.00%1100.00%


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, 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; 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_to_pfn_t(pfn, PFN_DEV)); 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; }

Contributors

PersonTokensPropCommitsCommitProp
thomas hellstromthomas hellstrom63783.60%960.00%
jerome glissejerome glisse9011.81%213.33%
dave airliedave airlie172.23%16.67%
david herrmanndavid herrmann101.31%16.67%
dan williamsdan williams50.66%16.67%
li binli bin30.39%16.67%
Total762100.00%15100.00%


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); }

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PersonTokensPropCommitsCommitProp
thomas hellstromthomas hellstrom48100.00%2100.00%
Total48100.00%2100.00%


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; }

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thomas hellstromthomas hellstrom37100.00%1100.00%
Total37100.00%1100.00%

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; }

Contributors

PersonTokensPropCommitsCommitProp
thomas hellstromthomas hellstrom6154.46%250.00%
david herrmanndavid herrmann4842.86%125.00%
joe perchesjoe perches32.68%125.00%
Total112100.00%4100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
thomas hellstromthomas hellstrom9862.42%360.00%
david herrmanndavid herrmann5736.31%120.00%
konstantin khlebnikovkonstantin khlebnikov21.27%120.00%
Total157100.00%5100.00%

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; }

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PersonTokensPropCommitsCommitProp
thomas hellstromthomas hellstrom60100.00%2100.00%
Total60100.00%2100.00%

EXPORT_SYMBOL(ttm_fbdev_mmap);

Overall Contributors

PersonTokensPropCommitsCommitProp
thomas hellstromthomas hellstrom115982.32%1155.00%
david herrmanndavid herrmann1188.38%15.00%
jerome glissejerome glisse906.39%210.00%
dave airliedave airlie171.21%15.00%
joe perchesjoe perches100.71%15.00%
dan williamsdan williams80.57%15.00%
li binli bin30.21%15.00%
konstantin khlebnikovkonstantin khlebnikov20.14%15.00%
alexey dobriyanalexey dobriyan10.07%15.00%
Total1408100.00%20100.00%
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