static int privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset, int prot, vm_page_t *mres) { struct privcmd_map *map = object->handle; vm_pindex_t pidx; vm_page_t page, oldm; if (map->mapped != true) return (VM_PAGER_FAIL); pidx = OFF_TO_IDX(offset); if (pidx >= map->size || BIT_ISSET(map->size, pidx, map->err)) return (VM_PAGER_FAIL); page = PHYS_TO_VM_PAGE(map->phys_base_addr + offset); if (page == NULL) return (VM_PAGER_FAIL); KASSERT((page->flags & PG_FICTITIOUS) != 0, ("not fictitious %p", page)); KASSERT(page->wire_count == 1, ("wire_count not 1 %p", page)); KASSERT(vm_page_busied(page) == 0, ("page %p is busy", page)); if (*mres != NULL) { oldm = *mres; vm_page_lock(oldm); vm_page_free(oldm); vm_page_unlock(oldm); *mres = NULL; } vm_page_insert(page, object, pidx); page->valid = VM_PAGE_BITS_ALL; vm_page_xbusy(page); *mres = page; return (VM_PAGER_OK); }
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 = PHYS_TO_VM_PAGE(bo->mem.bus.base + bo->mem.bus.offset + offset); KASSERT((m->flags & PG_FICTITIOUS) != 0, ("physical address %#jx not fictitious", (uintmax_t)(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; }