From 5ae0283e831a94c714fce61063e4724baf364ef3 Mon Sep 17 00:00:00 2001 From: Felix Kuehling Date: Fri, 23 Mar 2018 15:32:33 -0400 Subject: [PATCH] drm/amdgpu: Add userptr support for KFD This adds support for allocating, mapping, unmapping and freeing userptr BOs, and for handling MMU notifiers. v2: updated a comment Signed-off-by: Felix Kuehling Reviewed-by: Oded Gabbay Signed-off-by: Oded Gabbay --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 11 + .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 567 +++++++++++++++++- 2 files changed, 554 insertions(+), 24 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h index 83e0c5c331d2..c3024b143f3d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include "amdgpu_sync.h" @@ -59,7 +60,9 @@ struct kgd_mem { uint32_t mapping_flags; + atomic_t invalid; struct amdkfd_process_info *process_info; + struct page **user_pages; struct amdgpu_sync sync; @@ -84,6 +87,9 @@ struct amdkfd_process_info { struct list_head vm_list_head; /* List head for all KFD BOs that belong to a KFD process. */ struct list_head kfd_bo_list; + /* List of userptr BOs that are valid or invalid */ + struct list_head userptr_valid_list; + struct list_head userptr_inval_list; /* Lock to protect kfd_bo_list */ struct mutex lock; @@ -91,6 +97,11 @@ struct amdkfd_process_info { unsigned int n_vms; /* Eviction Fence */ struct amdgpu_amdkfd_fence *eviction_fence; + + /* MMU-notifier related fields */ + atomic_t evicted_bos; + struct delayed_work restore_userptr_work; + struct pid *pid; }; int amdgpu_amdkfd_init(void); diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index 2463ff6ac9ca..5296e24fd662 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -23,6 +23,7 @@ #define pr_fmt(fmt) "kfd2kgd: " fmt #include +#include #include #include "amdgpu_object.h" #include "amdgpu_vm.h" @@ -33,10 +34,20 @@ */ #define VI_BO_SIZE_ALIGN (0x8000) +/* BO flag to indicate a KFD userptr BO */ +#define AMDGPU_AMDKFD_USERPTR_BO (1ULL << 63) + +/* Userptr restore delay, just long enough to allow consecutive VM + * changes to accumulate + */ +#define AMDGPU_USERPTR_RESTORE_DELAY_MS 1 + /* Impose limit on how much memory KFD can use */ static struct { uint64_t max_system_mem_limit; + uint64_t max_userptr_mem_limit; int64_t system_mem_used; + int64_t userptr_mem_used; spinlock_t mem_limit_lock; } kfd_mem_limit; @@ -57,6 +68,7 @@ static const char * const domain_bit_to_string[] = { #define domain_string(domain) domain_bit_to_string[ffs(domain)-1] +static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work); static inline struct amdgpu_device *get_amdgpu_device(struct kgd_dev *kgd) @@ -78,6 +90,7 @@ static bool check_if_add_bo_to_vm(struct amdgpu_vm *avm, /* Set memory usage limits. Current, limits are * System (kernel) memory - 3/8th System RAM + * Userptr memory - 3/4th System RAM */ void amdgpu_amdkfd_gpuvm_init_mem_limits(void) { @@ -90,8 +103,10 @@ void amdgpu_amdkfd_gpuvm_init_mem_limits(void) spin_lock_init(&kfd_mem_limit.mem_limit_lock); kfd_mem_limit.max_system_mem_limit = (mem >> 1) - (mem >> 3); - pr_debug("Kernel memory limit %lluM\n", - (kfd_mem_limit.max_system_mem_limit >> 20)); + kfd_mem_limit.max_userptr_mem_limit = mem - (mem >> 2); + pr_debug("Kernel memory limit %lluM, userptr limit %lluM\n", + (kfd_mem_limit.max_system_mem_limit >> 20), + (kfd_mem_limit.max_userptr_mem_limit >> 20)); } static int amdgpu_amdkfd_reserve_system_mem_limit(struct amdgpu_device *adev, @@ -111,6 +126,16 @@ static int amdgpu_amdkfd_reserve_system_mem_limit(struct amdgpu_device *adev, goto err_no_mem; } kfd_mem_limit.system_mem_used += (acc_size + size); + } else if (domain == AMDGPU_GEM_DOMAIN_CPU) { + if ((kfd_mem_limit.system_mem_used + acc_size > + kfd_mem_limit.max_system_mem_limit) || + (kfd_mem_limit.userptr_mem_used + (size + acc_size) > + kfd_mem_limit.max_userptr_mem_limit)) { + ret = -ENOMEM; + goto err_no_mem; + } + kfd_mem_limit.system_mem_used += acc_size; + kfd_mem_limit.userptr_mem_used += size; } err_no_mem: spin_unlock(&kfd_mem_limit.mem_limit_lock); @@ -126,10 +151,16 @@ static void unreserve_system_mem_limit(struct amdgpu_device *adev, sizeof(struct amdgpu_bo)); spin_lock(&kfd_mem_limit.mem_limit_lock); - if (domain == AMDGPU_GEM_DOMAIN_GTT) + if (domain == AMDGPU_GEM_DOMAIN_GTT) { kfd_mem_limit.system_mem_used -= (acc_size + size); + } else if (domain == AMDGPU_GEM_DOMAIN_CPU) { + kfd_mem_limit.system_mem_used -= acc_size; + kfd_mem_limit.userptr_mem_used -= size; + } WARN_ONCE(kfd_mem_limit.system_mem_used < 0, "kfd system memory accounting unbalanced"); + WARN_ONCE(kfd_mem_limit.userptr_mem_used < 0, + "kfd userptr memory accounting unbalanced"); spin_unlock(&kfd_mem_limit.mem_limit_lock); } @@ -138,12 +169,17 @@ void amdgpu_amdkfd_unreserve_system_memory_limit(struct amdgpu_bo *bo) { spin_lock(&kfd_mem_limit.mem_limit_lock); - if (bo->preferred_domains == AMDGPU_GEM_DOMAIN_GTT) { + if (bo->flags & AMDGPU_AMDKFD_USERPTR_BO) { + kfd_mem_limit.system_mem_used -= bo->tbo.acc_size; + kfd_mem_limit.userptr_mem_used -= amdgpu_bo_size(bo); + } else if (bo->preferred_domains == AMDGPU_GEM_DOMAIN_GTT) { kfd_mem_limit.system_mem_used -= (bo->tbo.acc_size + amdgpu_bo_size(bo)); } WARN_ONCE(kfd_mem_limit.system_mem_used < 0, "kfd system memory accounting unbalanced"); + WARN_ONCE(kfd_mem_limit.userptr_mem_used < 0, + "kfd userptr memory accounting unbalanced"); spin_unlock(&kfd_mem_limit.mem_limit_lock); } @@ -506,7 +542,8 @@ static void remove_bo_from_vm(struct amdgpu_device *adev, } static void add_kgd_mem_to_kfd_bo_list(struct kgd_mem *mem, - struct amdkfd_process_info *process_info) + struct amdkfd_process_info *process_info, + bool userptr) { struct ttm_validate_buffer *entry = &mem->validate_list; struct amdgpu_bo *bo = mem->bo; @@ -515,10 +552,95 @@ static void add_kgd_mem_to_kfd_bo_list(struct kgd_mem *mem, entry->shared = true; entry->bo = &bo->tbo; mutex_lock(&process_info->lock); - list_add_tail(&entry->head, &process_info->kfd_bo_list); + if (userptr) + list_add_tail(&entry->head, &process_info->userptr_valid_list); + else + list_add_tail(&entry->head, &process_info->kfd_bo_list); mutex_unlock(&process_info->lock); } +/* Initializes user pages. It registers the MMU notifier and validates + * the userptr BO in the GTT domain. + * + * The BO must already be on the userptr_valid_list. Otherwise an + * eviction and restore may happen that leaves the new BO unmapped + * with the user mode queues running. + * + * Takes the process_info->lock to protect against concurrent restore + * workers. + * + * Returns 0 for success, negative errno for errors. + */ +static int init_user_pages(struct kgd_mem *mem, struct mm_struct *mm, + uint64_t user_addr) +{ + struct amdkfd_process_info *process_info = mem->process_info; + struct amdgpu_bo *bo = mem->bo; + struct ttm_operation_ctx ctx = { true, false }; + int ret = 0; + + mutex_lock(&process_info->lock); + + ret = amdgpu_ttm_tt_set_userptr(bo->tbo.ttm, user_addr, 0); + if (ret) { + pr_err("%s: Failed to set userptr: %d\n", __func__, ret); + goto out; + } + + ret = amdgpu_mn_register(bo, user_addr); + if (ret) { + pr_err("%s: Failed to register MMU notifier: %d\n", + __func__, ret); + goto out; + } + + /* If no restore worker is running concurrently, user_pages + * should not be allocated + */ + WARN(mem->user_pages, "Leaking user_pages array"); + + mem->user_pages = kvmalloc_array(bo->tbo.ttm->num_pages, + sizeof(struct page *), + GFP_KERNEL | __GFP_ZERO); + if (!mem->user_pages) { + pr_err("%s: Failed to allocate pages array\n", __func__); + ret = -ENOMEM; + goto unregister_out; + } + + ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, mem->user_pages); + if (ret) { + pr_err("%s: Failed to get user pages: %d\n", __func__, ret); + goto free_out; + } + + amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm, mem->user_pages); + + ret = amdgpu_bo_reserve(bo, true); + if (ret) { + pr_err("%s: Failed to reserve BO\n", __func__); + goto release_out; + } + amdgpu_ttm_placement_from_domain(bo, mem->domain); + ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx); + if (ret) + pr_err("%s: failed to validate BO\n", __func__); + amdgpu_bo_unreserve(bo); + +release_out: + if (ret) + release_pages(mem->user_pages, bo->tbo.ttm->num_pages); +free_out: + kvfree(mem->user_pages); + mem->user_pages = NULL; +unregister_out: + if (ret) + amdgpu_mn_unregister(bo); +out: + mutex_unlock(&process_info->lock); + return ret; +} + /* Reserving a BO and its page table BOs must happen atomically to * avoid deadlocks. Some operations update multiple VMs at once. Track * all the reservation info in a context structure. Optionally a sync @@ -748,7 +870,8 @@ static int update_gpuvm_pte(struct amdgpu_device *adev, } static int map_bo_to_gpuvm(struct amdgpu_device *adev, - struct kfd_bo_va_list *entry, struct amdgpu_sync *sync) + struct kfd_bo_va_list *entry, struct amdgpu_sync *sync, + bool no_update_pte) { int ret; @@ -762,6 +885,9 @@ static int map_bo_to_gpuvm(struct amdgpu_device *adev, return ret; } + if (no_update_pte) + return 0; + ret = update_gpuvm_pte(adev, entry, sync); if (ret) { pr_err("update_gpuvm_pte() failed\n"); @@ -820,6 +946,8 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info, mutex_init(&info->lock); INIT_LIST_HEAD(&info->vm_list_head); INIT_LIST_HEAD(&info->kfd_bo_list); + INIT_LIST_HEAD(&info->userptr_valid_list); + INIT_LIST_HEAD(&info->userptr_inval_list); info->eviction_fence = amdgpu_amdkfd_fence_create(dma_fence_context_alloc(1), @@ -830,6 +958,11 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info, goto create_evict_fence_fail; } + info->pid = get_task_pid(current->group_leader, PIDTYPE_PID); + atomic_set(&info->evicted_bos, 0); + INIT_DELAYED_WORK(&info->restore_userptr_work, + amdgpu_amdkfd_restore_userptr_worker); + *process_info = info; *ef = dma_fence_get(&info->eviction_fence->base); } @@ -872,6 +1005,7 @@ static int init_kfd_vm(struct amdgpu_vm *vm, void **process_info, dma_fence_put(*ef); *ef = NULL; *process_info = NULL; + put_pid(info->pid); create_evict_fence_fail: mutex_destroy(&info->lock); kfree(info); @@ -967,8 +1101,12 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev, /* Release per-process resources when last compute VM is destroyed */ if (!process_info->n_vms) { WARN_ON(!list_empty(&process_info->kfd_bo_list)); + WARN_ON(!list_empty(&process_info->userptr_valid_list)); + WARN_ON(!list_empty(&process_info->userptr_inval_list)); dma_fence_put(&process_info->eviction_fence->base); + cancel_delayed_work_sync(&process_info->restore_userptr_work); + put_pid(process_info->pid); mutex_destroy(&process_info->lock); kfree(process_info); } @@ -1003,9 +1141,10 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu( { struct amdgpu_device *adev = get_amdgpu_device(kgd); struct amdgpu_vm *avm = (struct amdgpu_vm *)vm; + uint64_t user_addr = 0; struct amdgpu_bo *bo; int byte_align; - u32 alloc_domain; + u32 domain, alloc_domain; u64 alloc_flags; uint32_t mapping_flags; int ret; @@ -1014,14 +1153,21 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu( * Check on which domain to allocate BO */ if (flags & ALLOC_MEM_FLAGS_VRAM) { - alloc_domain = AMDGPU_GEM_DOMAIN_VRAM; + domain = alloc_domain = AMDGPU_GEM_DOMAIN_VRAM; alloc_flags = AMDGPU_GEM_CREATE_VRAM_CLEARED; alloc_flags |= (flags & ALLOC_MEM_FLAGS_PUBLIC) ? AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED : AMDGPU_GEM_CREATE_NO_CPU_ACCESS; } else if (flags & ALLOC_MEM_FLAGS_GTT) { - alloc_domain = AMDGPU_GEM_DOMAIN_GTT; + domain = alloc_domain = AMDGPU_GEM_DOMAIN_GTT; alloc_flags = 0; + } else if (flags & ALLOC_MEM_FLAGS_USERPTR) { + domain = AMDGPU_GEM_DOMAIN_GTT; + alloc_domain = AMDGPU_GEM_DOMAIN_CPU; + alloc_flags = 0; + if (!offset || !*offset) + return -EINVAL; + user_addr = *offset; } else { return -EINVAL; } @@ -1078,18 +1224,34 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu( } bo->kfd_bo = *mem; (*mem)->bo = bo; + if (user_addr) + bo->flags |= AMDGPU_AMDKFD_USERPTR_BO; (*mem)->va = va; - (*mem)->domain = alloc_domain; + (*mem)->domain = domain; (*mem)->mapped_to_gpu_memory = 0; (*mem)->process_info = avm->process_info; - add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info); + add_kgd_mem_to_kfd_bo_list(*mem, avm->process_info, user_addr); + + if (user_addr) { + ret = init_user_pages(*mem, current->mm, user_addr); + if (ret) { + mutex_lock(&avm->process_info->lock); + list_del(&(*mem)->validate_list.head); + mutex_unlock(&avm->process_info->lock); + goto allocate_init_user_pages_failed; + } + } if (offset) *offset = amdgpu_bo_mmap_offset(bo); return 0; +allocate_init_user_pages_failed: + amdgpu_bo_unref(&bo); + /* Don't unreserve system mem limit twice */ + goto err_reserve_system_mem; err_bo_create: unreserve_system_mem_limit(adev, size, alloc_domain); err_reserve_system_mem: @@ -1122,12 +1284,24 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu( * be freed anyway */ + /* No more MMU notifiers */ + amdgpu_mn_unregister(mem->bo); + /* Make sure restore workers don't access the BO any more */ bo_list_entry = &mem->validate_list; mutex_lock(&process_info->lock); list_del(&bo_list_entry->head); mutex_unlock(&process_info->lock); + /* Free user pages if necessary */ + if (mem->user_pages) { + pr_debug("%s: Freeing user_pages array\n", __func__); + if (mem->user_pages[0]) + release_pages(mem->user_pages, + mem->bo->tbo.ttm->num_pages); + kvfree(mem->user_pages); + } + ret = reserve_bo_and_cond_vms(mem, NULL, BO_VM_ALL, &ctx); if (unlikely(ret)) return ret; @@ -1173,21 +1347,32 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu( struct kfd_bo_va_list *bo_va_entry = NULL; struct kfd_bo_va_list *bo_va_entry_aql = NULL; unsigned long bo_size; + bool is_invalid_userptr = false; - /* Make sure restore is not running concurrently. + bo = mem->bo; + if (!bo) { + pr_err("Invalid BO when mapping memory to GPU\n"); + return -EINVAL; + } + + /* Make sure restore is not running concurrently. Since we + * don't map invalid userptr BOs, we rely on the next restore + * worker to do the mapping */ mutex_lock(&mem->process_info->lock); - mutex_lock(&mem->lock); - - bo = mem->bo; - - if (!bo) { - pr_err("Invalid BO when mapping memory to GPU\n"); - ret = -EINVAL; - goto out; + /* Lock mmap-sem. If we find an invalid userptr BO, we can be + * sure that the MMU notifier is no longer running + * concurrently and the queues are actually stopped + */ + if (amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) { + down_write(¤t->mm->mmap_sem); + is_invalid_userptr = atomic_read(&mem->invalid); + up_write(¤t->mm->mmap_sem); } + mutex_lock(&mem->lock); + domain = mem->domain; bo_size = bo->tbo.mem.size; @@ -1200,6 +1385,14 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu( if (unlikely(ret)) goto out; + /* Userptr can be marked as "not invalid", but not actually be + * validated yet (still in the system domain). In that case + * the queues are still stopped and we can leave mapping for + * the next restore worker + */ + if (bo->tbo.mem.mem_type == TTM_PL_SYSTEM) + is_invalid_userptr = true; + if (check_if_add_bo_to_vm(avm, mem)) { ret = add_bo_to_vm(adev, mem, avm, false, &bo_va_entry); @@ -1217,7 +1410,8 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu( goto add_bo_to_vm_failed; } - if (mem->mapped_to_gpu_memory == 0) { + if (mem->mapped_to_gpu_memory == 0 && + !amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) { /* Validate BO only once. The eviction fence gets added to BO * the first time it is mapped. Validate will wait for all * background evictions to complete. @@ -1235,7 +1429,8 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu( entry->va, entry->va + bo_size, entry); - ret = map_bo_to_gpuvm(adev, entry, ctx.sync); + ret = map_bo_to_gpuvm(adev, entry, ctx.sync, + is_invalid_userptr); if (ret) { pr_err("Failed to map radeon bo to gpuvm\n"); goto map_bo_to_gpuvm_failed; @@ -1418,13 +1613,337 @@ int amdgpu_amdkfd_gpuvm_map_gtt_bo_to_kernel(struct kgd_dev *kgd, return ret; } +/* Evict a userptr BO by stopping the queues if necessary + * + * Runs in MMU notifier, may be in RECLAIM_FS context. This means it + * cannot do any memory allocations, and cannot take any locks that + * are held elsewhere while allocating memory. Therefore this is as + * simple as possible, using atomic counters. + * + * It doesn't do anything to the BO itself. The real work happens in + * restore, where we get updated page addresses. This function only + * ensures that GPU access to the BO is stopped. + */ int amdgpu_amdkfd_evict_userptr(struct kgd_mem *mem, struct mm_struct *mm) { - /* TODO */ + struct amdkfd_process_info *process_info = mem->process_info; + int invalid, evicted_bos; + int r = 0; + + invalid = atomic_inc_return(&mem->invalid); + evicted_bos = atomic_inc_return(&process_info->evicted_bos); + if (evicted_bos == 1) { + /* First eviction, stop the queues */ + r = kgd2kfd->quiesce_mm(mm); + if (r) + pr_err("Failed to quiesce KFD\n"); + schedule_delayed_work(&process_info->restore_userptr_work, + msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS)); + } + + return r; +} + +/* Update invalid userptr BOs + * + * Moves invalidated (evicted) userptr BOs from userptr_valid_list to + * userptr_inval_list and updates user pages for all BOs that have + * been invalidated since their last update. + */ +static int update_invalid_user_pages(struct amdkfd_process_info *process_info, + struct mm_struct *mm) +{ + struct kgd_mem *mem, *tmp_mem; + struct amdgpu_bo *bo; + struct ttm_operation_ctx ctx = { false, false }; + int invalid, ret; + + /* Move all invalidated BOs to the userptr_inval_list and + * release their user pages by migration to the CPU domain + */ + list_for_each_entry_safe(mem, tmp_mem, + &process_info->userptr_valid_list, + validate_list.head) { + if (!atomic_read(&mem->invalid)) + continue; /* BO is still valid */ + + bo = mem->bo; + + if (amdgpu_bo_reserve(bo, true)) + return -EAGAIN; + amdgpu_ttm_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_CPU); + ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx); + amdgpu_bo_unreserve(bo); + if (ret) { + pr_err("%s: Failed to invalidate userptr BO\n", + __func__); + return -EAGAIN; + } + + list_move_tail(&mem->validate_list.head, + &process_info->userptr_inval_list); + } + + if (list_empty(&process_info->userptr_inval_list)) + return 0; /* All evicted userptr BOs were freed */ + + /* Go through userptr_inval_list and update any invalid user_pages */ + list_for_each_entry(mem, &process_info->userptr_inval_list, + validate_list.head) { + invalid = atomic_read(&mem->invalid); + if (!invalid) + /* BO hasn't been invalidated since the last + * revalidation attempt. Keep its BO list. + */ + continue; + + bo = mem->bo; + + if (!mem->user_pages) { + mem->user_pages = + kvmalloc_array(bo->tbo.ttm->num_pages, + sizeof(struct page *), + GFP_KERNEL | __GFP_ZERO); + if (!mem->user_pages) { + pr_err("%s: Failed to allocate pages array\n", + __func__); + return -ENOMEM; + } + } else if (mem->user_pages[0]) { + release_pages(mem->user_pages, bo->tbo.ttm->num_pages); + } + + /* Get updated user pages */ + ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, + mem->user_pages); + if (ret) { + mem->user_pages[0] = NULL; + pr_info("%s: Failed to get user pages: %d\n", + __func__, ret); + /* Pretend it succeeded. It will fail later + * with a VM fault if the GPU tries to access + * it. Better than hanging indefinitely with + * stalled user mode queues. + */ + } + + /* Mark the BO as valid unless it was invalidated + * again concurrently + */ + if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid) + return -EAGAIN; + } + return 0; } +/* Validate invalid userptr BOs + * + * Validates BOs on the userptr_inval_list, and moves them back to the + * userptr_valid_list. Also updates GPUVM page tables with new page + * addresses and waits for the page table updates to complete. + */ +static int validate_invalid_user_pages(struct amdkfd_process_info *process_info) +{ + struct amdgpu_bo_list_entry *pd_bo_list_entries; + struct list_head resv_list, duplicates; + struct ww_acquire_ctx ticket; + struct amdgpu_sync sync; + + struct amdgpu_vm *peer_vm; + struct kgd_mem *mem, *tmp_mem; + struct amdgpu_bo *bo; + struct ttm_operation_ctx ctx = { false, false }; + int i, ret; + + pd_bo_list_entries = kcalloc(process_info->n_vms, + sizeof(struct amdgpu_bo_list_entry), + GFP_KERNEL); + if (!pd_bo_list_entries) { + pr_err("%s: Failed to allocate PD BO list entries\n", __func__); + return -ENOMEM; + } + + INIT_LIST_HEAD(&resv_list); + INIT_LIST_HEAD(&duplicates); + + /* Get all the page directory BOs that need to be reserved */ + i = 0; + list_for_each_entry(peer_vm, &process_info->vm_list_head, + vm_list_node) + amdgpu_vm_get_pd_bo(peer_vm, &resv_list, + &pd_bo_list_entries[i++]); + /* Add the userptr_inval_list entries to resv_list */ + list_for_each_entry(mem, &process_info->userptr_inval_list, + validate_list.head) { + list_add_tail(&mem->resv_list.head, &resv_list); + mem->resv_list.bo = mem->validate_list.bo; + mem->resv_list.shared = mem->validate_list.shared; + } + + /* Reserve all BOs and page tables for validation */ + ret = ttm_eu_reserve_buffers(&ticket, &resv_list, false, &duplicates); + WARN(!list_empty(&duplicates), "Duplicates should be empty"); + if (ret) + goto out; + + amdgpu_sync_create(&sync); + + /* Avoid triggering eviction fences when unmapping invalid + * userptr BOs (waits for all fences, doesn't use + * FENCE_OWNER_VM) + */ + list_for_each_entry(peer_vm, &process_info->vm_list_head, + vm_list_node) + amdgpu_amdkfd_remove_eviction_fence(peer_vm->root.base.bo, + process_info->eviction_fence, + NULL, NULL); + + ret = process_validate_vms(process_info); + if (ret) + goto unreserve_out; + + /* Validate BOs and update GPUVM page tables */ + list_for_each_entry_safe(mem, tmp_mem, + &process_info->userptr_inval_list, + validate_list.head) { + struct kfd_bo_va_list *bo_va_entry; + + bo = mem->bo; + + /* Copy pages array and validate the BO if we got user pages */ + if (mem->user_pages[0]) { + amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm, + mem->user_pages); + amdgpu_ttm_placement_from_domain(bo, mem->domain); + ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx); + if (ret) { + pr_err("%s: failed to validate BO\n", __func__); + goto unreserve_out; + } + } + + /* Validate succeeded, now the BO owns the pages, free + * our copy of the pointer array. Put this BO back on + * the userptr_valid_list. If we need to revalidate + * it, we need to start from scratch. + */ + kvfree(mem->user_pages); + mem->user_pages = NULL; + list_move_tail(&mem->validate_list.head, + &process_info->userptr_valid_list); + + /* Update mapping. If the BO was not validated + * (because we couldn't get user pages), this will + * clear the page table entries, which will result in + * VM faults if the GPU tries to access the invalid + * memory. + */ + list_for_each_entry(bo_va_entry, &mem->bo_va_list, bo_list) { + if (!bo_va_entry->is_mapped) + continue; + + ret = update_gpuvm_pte((struct amdgpu_device *) + bo_va_entry->kgd_dev, + bo_va_entry, &sync); + if (ret) { + pr_err("%s: update PTE failed\n", __func__); + /* make sure this gets validated again */ + atomic_inc(&mem->invalid); + goto unreserve_out; + } + } + } + + /* Update page directories */ + ret = process_update_pds(process_info, &sync); + +unreserve_out: + list_for_each_entry(peer_vm, &process_info->vm_list_head, + vm_list_node) + amdgpu_bo_fence(peer_vm->root.base.bo, + &process_info->eviction_fence->base, true); + ttm_eu_backoff_reservation(&ticket, &resv_list); + amdgpu_sync_wait(&sync, false); + amdgpu_sync_free(&sync); +out: + kfree(pd_bo_list_entries); + + return ret; +} + +/* Worker callback to restore evicted userptr BOs + * + * Tries to update and validate all userptr BOs. If successful and no + * concurrent evictions happened, the queues are restarted. Otherwise, + * reschedule for another attempt later. + */ +static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work) +{ + struct delayed_work *dwork = to_delayed_work(work); + struct amdkfd_process_info *process_info = + container_of(dwork, struct amdkfd_process_info, + restore_userptr_work); + struct task_struct *usertask; + struct mm_struct *mm; + int evicted_bos; + + evicted_bos = atomic_read(&process_info->evicted_bos); + if (!evicted_bos) + return; + + /* Reference task and mm in case of concurrent process termination */ + usertask = get_pid_task(process_info->pid, PIDTYPE_PID); + if (!usertask) + return; + mm = get_task_mm(usertask); + if (!mm) { + put_task_struct(usertask); + return; + } + + mutex_lock(&process_info->lock); + + if (update_invalid_user_pages(process_info, mm)) + goto unlock_out; + /* userptr_inval_list can be empty if all evicted userptr BOs + * have been freed. In that case there is nothing to validate + * and we can just restart the queues. + */ + if (!list_empty(&process_info->userptr_inval_list)) { + if (atomic_read(&process_info->evicted_bos) != evicted_bos) + goto unlock_out; /* Concurrent eviction, try again */ + + if (validate_invalid_user_pages(process_info)) + goto unlock_out; + } + /* Final check for concurrent evicton and atomic update. If + * another eviction happens after successful update, it will + * be a first eviction that calls quiesce_mm. The eviction + * reference counting inside KFD will handle this case. + */ + if (atomic_cmpxchg(&process_info->evicted_bos, evicted_bos, 0) != + evicted_bos) + goto unlock_out; + evicted_bos = 0; + if (kgd2kfd->resume_mm(mm)) { + pr_err("%s: Failed to resume KFD\n", __func__); + /* No recovery from this failure. Probably the CP is + * hanging. No point trying again. + */ + } +unlock_out: + mutex_unlock(&process_info->lock); + mmput(mm); + put_task_struct(usertask); + + /* If validation failed, reschedule another attempt */ + if (evicted_bos) + schedule_delayed_work(&process_info->restore_userptr_work, + msecs_to_jiffies(AMDGPU_USERPTR_RESTORE_DELAY_MS)); +} + /** amdgpu_amdkfd_gpuvm_restore_process_bos - Restore all BOs for the given * KFD process identified by process_info *