msm_gem.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright (C) 2013 Red Hat
  4 * Author: Rob Clark <robdclark@gmail.com>
  5 */
  6
  7#ifndef __MSM_GEM_H__
  8#define __MSM_GEM_H__
  9
 10#include "msm_mmu.h"
 11#include <linux/kref.h>
 12#include <linux/dma-resv.h>
 13#include "drm/drm_exec.h"
 14#include "drm/drm_gpuvm.h"
 15#include "drm/gpu_scheduler.h"
 16#include "msm_drv.h"
 17
 18/* Make all GEM related WARN_ON()s ratelimited.. when things go wrong they
 19 * tend to go wrong 1000s of times in a short timespan.
 20 */
 21#define GEM_WARN_ON(x)  WARN_RATELIMIT(x, "%s", __stringify(x))
 22
 23/* Additional internal-use only BO flags: */
 24#define MSM_BO_STOLEN        0x10000000    /* try to use stolen/splash memory */
 25#define MSM_BO_MAP_PRIV      0x20000000    /* use IOMMU_PRIV when mapping */
 26
 27/**
 28 * struct msm_gem_vm_log_entry - An entry in the VM log
 29 *
 30 * For userspace managed VMs, a log of recent VM updates is tracked and
 31 * captured in GPU devcore dumps, to aid debugging issues caused by (for
 32 * example) incorrectly synchronized VM updates
 33 */
 34struct msm_gem_vm_log_entry {
 35	const char *op;
 36	uint64_t iova;
 37	uint64_t range;
 38	int queue_id;
 39};
 40
 41/**
 42 * struct msm_gem_vm - VM object
 43 *
 44 * A VM object representing a GPU (or display or GMU or ...) virtual address
 45 * space.
 46 *
 47 * In the case of GPU, if per-process address spaces are supported, the address
 48 * space is split into two VMs, which map to TTBR0 and TTBR1 in the SMMU.  TTBR0
 49 * is used for userspace objects, and is unique per msm_context/drm_file, while
 50 * TTBR1 is the same for all processes.  (The kernel controlled ringbuffer and
 51 * a few other kernel controlled buffers live in TTBR1.)
 52 *
 53 * The GPU TTBR0 vm can be managed by userspace or by the kernel, depending on
 54 * whether userspace supports VM_BIND.  All other vm's are managed by the kernel.
 55 * (Managed by kernel means the kernel is responsible for VA allocation.)
 56 *
 57 * Note that because VM_BIND allows a given BO to be mapped multiple times in
 58 * a VM, and therefore have multiple VMA's in a VM, there is an extra object
 59 * provided by drm_gpuvm infrastructure.. the drm_gpuvm_bo, which is not
 60 * embedded in any larger driver structure.  The GEM object holds a list of
 61 * drm_gpuvm_bo, which in turn holds a list of msm_gem_vma.  A linked vma
 62 * holds a reference to the vm_bo, and drops it when the vma is unlinked.
 63 * So we just need to call drm_gpuvm_bo_obtain() to return a ref to an
 64 * existing vm_bo, or create a new one.  Once the vma is linked, the ref
 65 * to the vm_bo can be dropped (since the vma is holding one).
 66 */
 67struct msm_gem_vm {
 68	/** @base: Inherit from drm_gpuvm. */
 69	struct drm_gpuvm base;
 70
 71	/**
 72	 * @sched: Scheduler used for asynchronous VM_BIND request.
 73	 *
 74	 * Unused for kernel managed VMs (where all operations are synchronous).
 75	 */
 76	struct drm_gpu_scheduler sched;
 77
 78	/**
 79	 * @prealloc_throttle: Used to throttle VM_BIND ops if too much pre-
 80	 * allocated memory is in flight.
 81	 *
 82	 * Because we have to pre-allocate pgtable pages for the worst case
 83	 * (ie. new mappings do not share any PTEs with existing mappings)
 84	 * we could end up consuming a lot of resources transiently.  The
 85	 * prealloc_throttle puts an upper bound on that.
 86	 */
 87	struct {
 88		/** @wait: Notified when preallocated resources are released */
 89		wait_queue_head_t wait;
 90
 91		/**
 92		 * @in_flight: The # of preallocated pgtable pages in-flight
 93		 * for queued VM_BIND jobs.
 94		 */
 95		atomic_t in_flight;
 96	} prealloc_throttle;
 97
 98	/**
 99	 * @mm: Memory management for kernel managed VA allocations
100	 *
101	 * Only used for kernel managed VMs, unused for user managed VMs.
102	 *
103	 * Protected by vm lock.  See msm_gem_lock_vm_and_obj(), for ex.
104	 */
105	struct drm_mm mm;
106
107	/** @mmu: The mmu object which manages the pgtables */
108	struct msm_mmu *mmu;
109
110	/** @mmu_lock: Protects access to the mmu */
111	struct mutex mmu_lock;
112
113	/**
114	 * @pid: For address spaces associated with a specific process, this
115	 * will be non-NULL:
116	 */
117	struct pid *pid;
118
119	/** @last_fence: Fence for last pending work scheduled on the VM */
120	struct dma_fence *last_fence;
121
122	/** @log: A log of recent VM updates */
123	struct msm_gem_vm_log_entry *log;
124
125	/** @log_shift: length of @log is (1 << @log_shift) */
126	uint32_t log_shift;
127
128	/** @log_idx: index of next @log entry to write */
129	uint32_t log_idx;
130
131	/** @faults: the number of GPU hangs associated with this address space */
132	int faults;
133
134	/** @managed: is this a kernel managed VM? */
135	bool managed;
136
137	/**
138	 * @unusable: True if the VM has turned unusable because something
139	 * bad happened during an asynchronous request.
140	 *
141	 * We don't try to recover from such failures, because this implies
142	 * informing userspace about the specific operation that failed, and
143	 * hoping the userspace driver can replay things from there. This all
144	 * sounds very complicated for little gain.
145	 *
146	 * Instead, we should just flag the VM as unusable, and fail any
147	 * further request targeting this VM.
148	 *
149	 * As an analogy, this would be mapped to a VK_ERROR_DEVICE_LOST
150	 * situation, where the logical device needs to be re-created.
151	 */
152	bool unusable;
153};
154#define to_msm_vm(x) container_of(x, struct msm_gem_vm, base)
155
156struct drm_gpuvm *
157msm_gem_vm_create(struct drm_device *drm, struct msm_mmu *mmu, const char *name,
158		  u64 va_start, u64 va_size, bool managed);
159
160void msm_gem_vm_close(struct drm_gpuvm *gpuvm);
161void msm_gem_vm_unusable(struct drm_gpuvm *gpuvm);
162
163struct msm_fence_context;
164
165#define MSM_VMA_DUMP (DRM_GPUVA_USERBITS << 0)
166
167/**
168 * struct msm_gem_vma - a VMA mapping
169 *
170 * Represents a combination of a GEM object plus a VM.
171 */
172struct msm_gem_vma {
173	/** @base: inherit from drm_gpuva */
174	struct drm_gpuva base;
175
176	/**
177	 * @node: mm node for VA allocation
178	 *
179	 * Only used by kernel managed VMs
180	 */
181	struct drm_mm_node node;
182
183	/** @mapped: Is this VMA mapped? */
184	bool mapped;
185};
186#define to_msm_vma(x) container_of(x, struct msm_gem_vma, base)
187
188struct drm_gpuva *
189msm_gem_vma_new(struct drm_gpuvm *vm, struct drm_gem_object *obj,
190		u64 offset, u64 range_start, u64 range_end);
191void msm_gem_vma_unmap(struct drm_gpuva *vma, const char *reason);
192int msm_gem_vma_map(struct drm_gpuva *vma, int prot, struct sg_table *sgt);
193void msm_gem_vma_close(struct drm_gpuva *vma);
194
195struct msm_gem_object {
196	struct drm_gem_object base;
197
198	uint32_t flags;
199
200	/**
201	 * madv: are the backing pages purgeable?
202	 *
203	 * Protected by obj lock and LRU lock
204	 */
205	uint8_t madv;
206
207	/**
208	 * count of active vmap'ing
209	 */
210	uint8_t vmap_count;
211
212	/**
213	 * Node in list of all objects (mainly for debugfs, protected by
214	 * priv->obj_lock
215	 */
216	struct list_head node;
217
218	struct page **pages;
219	struct sg_table *sgt;
220	void *vaddr;
221
222	char name[32]; /* Identifier to print for the debugfs files */
223
224	/* userspace metadata backchannel */
225	void *metadata;
226	u32 metadata_size;
227
228	/**
229	 * pin_count: Number of times the pages are pinned
230	 *
231	 * Protected by LRU lock.
232	 */
233	int pin_count;
234
235	/**
236	 * @vma_ref: Reference count of VMA users.
237	 *
238	 * With the vm_bo/vma holding a reference to the GEM object, we'd
239	 * otherwise have to actively tear down a VMA when, for example,
240	 * a buffer is unpinned for scanout, vs. the pre-drm_gpuvm approach
241	 * where a VMA did not hold a reference to the BO, but instead was
242	 * implicitly torn down when the BO was freed.
243	 *
244	 * To regain the lazy VMA teardown, we use the @vma_ref.  It is
245	 * incremented for any of the following:
246	 *
247	 * 1) the BO is exported as a dma_buf
248	 * 2) the BO has open userspace handle
249	 *
250	 * All of those conditions will hold an reference to the BO,
251	 * preventing it from being freed.  So lazily keeping around the
252	 * VMA will not prevent the BO from being freed.  (Or rather, the
253	 * reference loop is harmless in this case.)
254	 *
255	 * When the @vma_ref drops to zero, then kms->vm VMA will be
256	 * torn down.
257	 */
258	atomic_t vma_ref;
259};
260#define to_msm_bo(x) container_of(x, struct msm_gem_object, base)
261
262void msm_gem_vma_get(struct drm_gem_object *obj);
263void msm_gem_vma_put(struct drm_gem_object *obj);
264
265uint64_t msm_gem_mmap_offset(struct drm_gem_object *obj);
266int msm_gem_prot(struct drm_gem_object *obj);
267int msm_gem_pin_vma_locked(struct drm_gem_object *obj, struct drm_gpuva *vma);
268void msm_gem_unpin_locked(struct drm_gem_object *obj);
269void msm_gem_unpin_active(struct drm_gem_object *obj);
270struct drm_gpuva *msm_gem_get_vma_locked(struct drm_gem_object *obj,
271					 struct drm_gpuvm *vm);
272int msm_gem_get_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm,
273		     uint64_t *iova);
274int msm_gem_set_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm,
275		     uint64_t iova);
276int msm_gem_get_and_pin_iova_range(struct drm_gem_object *obj,
277				   struct drm_gpuvm *vm, uint64_t *iova,
278				   u64 range_start, u64 range_end);
279int msm_gem_get_and_pin_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm,
280			     uint64_t *iova);
281void msm_gem_unpin_iova(struct drm_gem_object *obj, struct drm_gpuvm *vm);
282void msm_gem_pin_obj_locked(struct drm_gem_object *obj);
283struct page **msm_gem_get_pages_locked(struct drm_gem_object *obj, unsigned madv);
284struct page **msm_gem_pin_pages_locked(struct drm_gem_object *obj);
285void msm_gem_unpin_pages_locked(struct drm_gem_object *obj);
286int msm_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
287		struct drm_mode_create_dumb *args);
288int msm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
289		uint32_t handle, uint64_t *offset);
290void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj);
291void *msm_gem_get_vaddr(struct drm_gem_object *obj);
292void *msm_gem_get_vaddr_active(struct drm_gem_object *obj);
293void msm_gem_put_vaddr_locked(struct drm_gem_object *obj);
294void msm_gem_put_vaddr(struct drm_gem_object *obj);
295int msm_gem_madvise(struct drm_gem_object *obj, unsigned madv);
296bool msm_gem_active(struct drm_gem_object *obj);
297int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout);
298int msm_gem_cpu_fini(struct drm_gem_object *obj);
299int msm_gem_new_handle(struct drm_device *dev, struct drm_file *file,
300		size_t size, uint32_t flags, uint32_t *handle, char *name);
301struct drm_gem_object *msm_gem_new(struct drm_device *dev,
302		size_t size, uint32_t flags);
303void *msm_gem_kernel_new(struct drm_device *dev, size_t size, uint32_t flags,
304			 struct drm_gpuvm *vm, struct drm_gem_object **bo,
305			 uint64_t *iova);
306void msm_gem_kernel_put(struct drm_gem_object *bo, struct drm_gpuvm *vm);
307struct drm_gem_object *msm_gem_import(struct drm_device *dev,
308		struct dma_buf *dmabuf, struct sg_table *sgt);
309__printf(2, 3)
310void msm_gem_object_set_name(struct drm_gem_object *bo, const char *fmt, ...);
311
312#ifdef CONFIG_DEBUG_FS
313struct msm_gem_stats {
314	struct {
315		unsigned count;
316		size_t size;
317	} all, active, resident, purgeable, purged;
318};
319
320void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
321		struct msm_gem_stats *stats);
322void msm_gem_describe_objects(struct list_head *list, struct seq_file *m);
323#endif
324
325static inline void
326msm_gem_lock(struct drm_gem_object *obj)
327{
328	dma_resv_lock(obj->resv, NULL);
329}
330
331static inline bool __must_check
332msm_gem_trylock(struct drm_gem_object *obj)
333{
334	return dma_resv_trylock(obj->resv);
335}
336
337static inline int
338msm_gem_lock_interruptible(struct drm_gem_object *obj)
339{
340	return dma_resv_lock_interruptible(obj->resv, NULL);
341}
342
343static inline void
344msm_gem_unlock(struct drm_gem_object *obj)
345{
346	dma_resv_unlock(obj->resv);
347}
348
349/**
350 * msm_gem_lock_vm_and_obj() - Helper to lock an obj + VM
351 * @exec: the exec context helper which will be initalized
352 * @obj: the GEM object to lock
353 * @vm: the VM to lock
354 *
355 * Operations which modify a VM frequently need to lock both the VM and
356 * the object being mapped/unmapped/etc.  This helper uses drm_exec to
357 * acquire both locks, dealing with potential deadlock/backoff scenarios
358 * which arise when multiple locks are involved.
359 */
360static inline int
361msm_gem_lock_vm_and_obj(struct drm_exec *exec,
362			struct drm_gem_object *obj,
363			struct drm_gpuvm *vm)
364{
365	int ret = 0;
366
367	drm_exec_init(exec, 0, 2);
368	drm_exec_until_all_locked (exec) {
369		ret = drm_exec_lock_obj(exec, drm_gpuvm_resv_obj(vm));
370		if (!ret && (obj->resv != drm_gpuvm_resv(vm)))
371			ret = drm_exec_lock_obj(exec, obj);
372		drm_exec_retry_on_contention(exec);
373		if (GEM_WARN_ON(ret))
374			break;
375	}
376
377	return ret;
378}
379
380static inline void
381msm_gem_assert_locked(struct drm_gem_object *obj)
382{
383	/*
384	 * Destroying the object is a special case.. msm_gem_free_object()
385	 * calls many things that WARN_ON if the obj lock is not held.  But
386	 * acquiring the obj lock in msm_gem_free_object() can cause a
387	 * locking order inversion between reservation_ww_class_mutex and
388	 * fs_reclaim.
389	 *
390	 * This deadlock is not actually possible, because no one should
391	 * be already holding the lock when msm_gem_free_object() is called.
392	 * Unfortunately lockdep is not aware of this detail.  So when the
393	 * refcount drops to zero, we pretend it is already locked.
394	 */
395	lockdep_assert_once(
396		(kref_read(&obj->refcount) == 0) ||
397		(lockdep_is_held(&obj->resv->lock.base) != LOCK_STATE_NOT_HELD)
398	);
399}
400
401/* imported/exported objects are not purgeable: */
402static inline bool is_unpurgeable(struct msm_gem_object *msm_obj)
403{
404	return drm_gem_is_imported(&msm_obj->base) || msm_obj->pin_count;
405}
406
407static inline bool is_purgeable(struct msm_gem_object *msm_obj)
408{
409	return (msm_obj->madv == MSM_MADV_DONTNEED) && msm_obj->sgt &&
410			!is_unpurgeable(msm_obj);
411}
412
413static inline bool is_vunmapable(struct msm_gem_object *msm_obj)
414{
415	msm_gem_assert_locked(&msm_obj->base);
416	return (msm_obj->vmap_count == 0) && msm_obj->vaddr;
417}
418
419static inline bool is_unevictable(struct msm_gem_object *msm_obj)
420{
421	return is_unpurgeable(msm_obj) || msm_obj->vaddr;
422}
423
424void msm_gem_purge(struct drm_gem_object *obj);
425void msm_gem_evict(struct drm_gem_object *obj);
426void msm_gem_vunmap(struct drm_gem_object *obj);
427
428/* Created per submit-ioctl, to track bo's and cmdstream bufs, etc,
429 * associated with the cmdstream submission for synchronization (and
430 * make it easier to unwind when things go wrong, etc).
431 */
432struct msm_gem_submit {
433	struct drm_sched_job base;
434	struct kref ref;
435	struct drm_device *dev;
436	struct msm_gpu *gpu;
437	struct drm_gpuvm *vm;
438	struct list_head node;   /* node in ring submit list */
439	struct drm_exec exec;
440	uint32_t seqno;		/* Sequence number of the submit on the ring */
441
442	/* Hw fence, which is created when the scheduler executes the job, and
443	 * is signaled when the hw finishes (via seqno write from cmdstream)
444	 */
445	struct dma_fence *hw_fence;
446
447	/* Userspace visible fence, which is signaled by the scheduler after
448	 * the hw_fence is signaled.
449	 */
450	struct dma_fence *user_fence;
451
452	int fence_id;       /* key into queue->fence_idr */
453	struct msm_gpu_submitqueue *queue;
454	struct pid *pid;    /* submitting process */
455	bool bos_pinned : 1;
456	bool fault_dumped:1;/* Limit devcoredump dumping to one per submit */
457	bool in_rb : 1;     /* "sudo" mode, copy cmds into RB */
458	struct msm_ringbuffer *ring;
459	unsigned int nr_cmds;
460	unsigned int nr_bos;
461	u32 ident;	   /* A "identifier" for the submit for logging */
462	struct {
463		uint32_t type;
464		uint32_t size;  /* in dwords */
465		uint64_t iova;
466		uint32_t offset;/* in dwords */
467		uint32_t idx;   /* cmdstream buffer idx in bos[] */
468		uint32_t nr_relocs;
469		struct drm_msm_gem_submit_reloc *relocs;
470	} *cmd;  /* array of size nr_cmds */
471	struct {
472		uint32_t flags;
473		union {
474			struct drm_gem_object *obj;
475			uint32_t handle;
476		};
477		struct drm_gpuvm_bo *vm_bo;
478		uint64_t iova;
479	} bos[];
480};
481
482static inline struct msm_gem_submit *to_msm_submit(struct drm_sched_job *job)
483{
484	return container_of(job, struct msm_gem_submit, base);
485}
486
487void __msm_gem_submit_destroy(struct kref *kref);
488
489static inline void msm_gem_submit_get(struct msm_gem_submit *submit)
490{
491	kref_get(&submit->ref);
492}
493
494static inline void msm_gem_submit_put(struct msm_gem_submit *submit)
495{
496	kref_put(&submit->ref, __msm_gem_submit_destroy);
497}
498
499void msm_submit_retire(struct msm_gem_submit *submit);
500
501#endif /* __MSM_GEM_H__ */