xref: /dragonfly/sys/dev/drm/i915/intel_ringbuffer.h (revision 3f2dd94a569761201b5b0a18b2f697f97fe1b9dc)
1 #ifndef _INTEL_RINGBUFFER_H_
2 #define _INTEL_RINGBUFFER_H_
3 
4 #include <linux/hashtable.h>
5 #include "i915_gem_batch_pool.h"
6 #include "i915_gem_request.h"
7 #include "i915_gem_timeline.h"
8 #include "i915_selftest.h"
9 
10 struct drm_printer;
11 
12 #define I915_CMD_HASH_ORDER 9
13 
14 /* Early gen2 devices have a cacheline of just 32 bytes, using 64 is overkill,
15  * but keeps the logic simple. Indeed, the whole purpose of this macro is just
16  * to give some inclination as to some of the magic values used in the various
17  * workarounds!
18  */
19 #define CACHELINE_BYTES 64
20 #define CACHELINE_DWORDS (CACHELINE_BYTES / sizeof(uint32_t))
21 
22 struct intel_hw_status_page {
23           struct i915_vma *vma;
24           u32 *page_addr;
25           u32 ggtt_offset;
26 };
27 
28 #define I915_READ_TAIL(engine) I915_READ(RING_TAIL((engine)->mmio_base))
29 #define I915_WRITE_TAIL(engine, val) I915_WRITE(RING_TAIL((engine)->mmio_base), val)
30 
31 #define I915_READ_START(engine) I915_READ(RING_START((engine)->mmio_base))
32 #define I915_WRITE_START(engine, val) I915_WRITE(RING_START((engine)->mmio_base), val)
33 
34 #define I915_READ_HEAD(engine)  I915_READ(RING_HEAD((engine)->mmio_base))
35 #define I915_WRITE_HEAD(engine, val) I915_WRITE(RING_HEAD((engine)->mmio_base), val)
36 
37 #define I915_READ_CTL(engine) I915_READ(RING_CTL((engine)->mmio_base))
38 #define I915_WRITE_CTL(engine, val) I915_WRITE(RING_CTL((engine)->mmio_base), val)
39 
40 #define I915_READ_IMR(engine) I915_READ(RING_IMR((engine)->mmio_base))
41 #define I915_WRITE_IMR(engine, val) I915_WRITE(RING_IMR((engine)->mmio_base), val)
42 
43 #define I915_READ_MODE(engine) I915_READ(RING_MI_MODE((engine)->mmio_base))
44 #define I915_WRITE_MODE(engine, val) I915_WRITE(RING_MI_MODE((engine)->mmio_base), val)
45 
46 /* seqno size is actually only a uint32, but since we plan to use MI_FLUSH_DW to
47  * do the writes, and that must have qw aligned offsets, simply pretend it's 8b.
48  */
49 #define gen8_semaphore_seqno_size sizeof(uint64_t)
50 #define GEN8_SEMAPHORE_OFFSET(__from, __to)                                \
51           (((__from) * I915_NUM_ENGINES  + (__to)) * gen8_semaphore_seqno_size)
52 #define GEN8_SIGNAL_OFFSET(__ring, to)                           \
53           (dev_priv->semaphore->node.start + \
54            GEN8_SEMAPHORE_OFFSET((__ring)->id, (to)))
55 #define GEN8_WAIT_OFFSET(__ring, from)                           \
56           (dev_priv->semaphore->node.start + \
57            GEN8_SEMAPHORE_OFFSET(from, (__ring)->id))
58 
59 enum intel_engine_hangcheck_action {
60           ENGINE_IDLE = 0,
61           ENGINE_WAIT,
62           ENGINE_ACTIVE_SEQNO,
63           ENGINE_ACTIVE_HEAD,
64           ENGINE_ACTIVE_SUBUNITS,
65           ENGINE_WAIT_KICK,
66           ENGINE_DEAD,
67 };
68 
69 static inline const char *
hangcheck_action_to_str(const enum intel_engine_hangcheck_action a)70 hangcheck_action_to_str(const enum intel_engine_hangcheck_action a)
71 {
72           switch (a) {
73           case ENGINE_IDLE:
74                     return "idle";
75           case ENGINE_WAIT:
76                     return "wait";
77           case ENGINE_ACTIVE_SEQNO:
78                     return "active seqno";
79           case ENGINE_ACTIVE_HEAD:
80                     return "active head";
81           case ENGINE_ACTIVE_SUBUNITS:
82                     return "active subunits";
83           case ENGINE_WAIT_KICK:
84                     return "wait kick";
85           case ENGINE_DEAD:
86                     return "dead";
87           }
88 
89           return "unknown";
90 }
91 
92 #define I915_MAX_SLICES       3
93 #define I915_MAX_SUBSLICES 3
94 
95 #define instdone_slice_mask(dev_priv__) \
96           (INTEL_GEN(dev_priv__) == 7 ? \
97            1 : INTEL_INFO(dev_priv__)->sseu.slice_mask)
98 
99 #define instdone_subslice_mask(dev_priv__) \
100           (INTEL_GEN(dev_priv__) == 7 ? \
101            1 : INTEL_INFO(dev_priv__)->sseu.subslice_mask)
102 
103 #define for_each_instdone_slice_subslice(dev_priv__, slice__, subslice__) \
104           for ((slice__) = 0, (subslice__) = 0; \
105                (slice__) < I915_MAX_SLICES; \
106                (subslice__) = ((subslice__) + 1) < I915_MAX_SUBSLICES ? (subslice__) + 1 : 0, \
107                  (slice__) += ((subslice__) == 0)) \
108                     for_each_if((BIT(slice__) & instdone_slice_mask(dev_priv__)) && \
109                                   (BIT(subslice__) & instdone_subslice_mask(dev_priv__)))
110 
111 struct intel_instdone {
112           u32 instdone;
113           /* The following exist only in the RCS engine */
114           u32 slice_common;
115           u32 sampler[I915_MAX_SLICES][I915_MAX_SUBSLICES];
116           u32 row[I915_MAX_SLICES][I915_MAX_SUBSLICES];
117 };
118 
119 struct intel_engine_hangcheck {
120           u64 acthd;
121           u32 seqno;
122           enum intel_engine_hangcheck_action action;
123           unsigned long action_timestamp;
124           int deadlock;
125           struct intel_instdone instdone;
126           struct drm_i915_gem_request *active_request;
127           bool stalled;
128 };
129 
130 struct intel_ring {
131           struct i915_vma *vma;
132           void *vaddr;
133 
134           struct list_head request_list;
135 
136           u32 head;
137           u32 tail;
138           u32 emit;
139 
140           u32 space;
141           u32 size;
142           u32 effective_size;
143 };
144 
145 struct i915_gem_context;
146 struct drm_i915_reg_table;
147 
148 /*
149  * we use a single page to load ctx workarounds so all of these
150  * values are referred in terms of dwords
151  *
152  * struct i915_wa_ctx_bb:
153  *  offset: specifies batch starting position, also helpful in case
154  *    if we want to have multiple batches at different offsets based on
155  *    some criteria. It is not a requirement at the moment but provides
156  *    an option for future use.
157  *  size: size of the batch in DWORDS
158  */
159 struct i915_ctx_workarounds {
160           struct i915_wa_ctx_bb {
161                     u32 offset;
162                     u32 size;
163           } indirect_ctx, per_ctx;
164           struct i915_vma *vma;
165 };
166 
167 struct drm_i915_gem_request;
168 struct intel_render_state;
169 
170 /*
171  * Engine IDs definitions.
172  * Keep instances of the same type engine together.
173  */
174 enum intel_engine_id {
175           RCS = 0,
176           BCS,
177           VCS,
178           VCS2,
179 #define _VCS(n) (VCS + (n))
180           VECS
181 };
182 
183 struct i915_priolist {
184           struct rb_node node;
185           struct list_head requests;
186           int priority;
187 };
188 
189 /**
190  * struct intel_engine_execlists - execlist submission queue and port state
191  *
192  * The struct intel_engine_execlists represents the combined logical state of
193  * driver and the hardware state for execlist mode of submission.
194  */
195 struct intel_engine_execlists {
196           /**
197            * @irq_tasklet: softirq tasklet for bottom handler
198            */
199           struct tasklet_struct irq_tasklet;
200 
201           /**
202            * @default_priolist: priority list for I915_PRIORITY_NORMAL
203            */
204           struct i915_priolist default_priolist;
205 
206           /**
207            * @no_priolist: priority lists disabled
208            */
209           bool no_priolist;
210 
211           /**
212            * @port: execlist port states
213            *
214            * For each hardware ELSP (ExecList Submission Port) we keep
215            * track of the last request and the number of times we submitted
216            * that port to hw. We then count the number of times the hw reports
217            * a context completion or preemption. As only one context can
218            * be active on hw, we limit resubmission of context to port[0]. This
219            * is called Lite Restore, of the context.
220            */
221           struct execlist_port {
222                     /**
223                      * @request_count: combined request and submission count
224                      */
225                     struct drm_i915_gem_request *request_count;
226 #define EXECLIST_COUNT_BITS 2
227 #define port_request(p) ptr_mask_bits((p)->request_count, EXECLIST_COUNT_BITS)
228 #define port_count(p) ptr_unmask_bits((p)->request_count, EXECLIST_COUNT_BITS)
229 #define port_pack(rq, count) ptr_pack_bits(rq, count, EXECLIST_COUNT_BITS)
230 #define port_unpack(p, count) ptr_unpack_bits((p)->request_count, count, EXECLIST_COUNT_BITS)
231 #define port_set(p, packed) ((p)->request_count = (packed))
232 #define port_isset(p) ((p)->request_count)
233 #define port_index(p, execlists) ((p) - (execlists)->port)
234 
235                     /**
236                      * @context_id: context ID for port
237                      */
238                     GEM_DEBUG_DECL(u32 context_id);
239 
240 #define EXECLIST_MAX_PORTS 2
241           } port[EXECLIST_MAX_PORTS];
242 
243           /**
244            * @active: is the HW active? We consider the HW as active after
245            * submitting any context for execution and until we have seen the
246            * last context completion event. After that, we do not expect any
247            * more events until we submit, and so can park the HW.
248            *
249            * As we have a small number of different sources from which we feed
250            * the HW, we track the state of each inside a single bitfield.
251            */
252           unsigned int active;
253 #define EXECLISTS_ACTIVE_USER 0
254 #define EXECLISTS_ACTIVE_PREEMPT 1
255 
256           /**
257            * @port_mask: number of execlist ports - 1
258            */
259           unsigned int port_mask;
260 
261           /**
262            * @queue: queue of requests, in priority lists
263            */
264           struct rb_root queue;
265 
266           /**
267            * @first: leftmost level in priority @queue
268            */
269           struct rb_node *first;
270 
271           /**
272            * @fw_domains: forcewake domains for irq tasklet
273            */
274           unsigned int fw_domains;
275 
276           /**
277            * @csb_head: context status buffer head
278            */
279           unsigned int csb_head;
280 
281           /**
282            * @csb_use_mmio: access csb through mmio, instead of hwsp
283            */
284           bool csb_use_mmio;
285 };
286 
287 #define INTEL_ENGINE_CS_MAX_NAME 8
288 
289 struct intel_engine_cs {
290           struct drm_i915_private *i915;
291           char name[INTEL_ENGINE_CS_MAX_NAME];
292           enum intel_engine_id id;
293           unsigned int uabi_id;
294           unsigned int hw_id;
295           unsigned int guc_id;
296 
297           u8 class;
298           u8 instance;
299           u32 context_size;
300           u32 mmio_base;
301           unsigned int irq_shift;
302 
303           struct intel_ring *buffer;
304           struct intel_timeline *timeline;
305 
306           struct intel_render_state *render_state;
307 
308           atomic_t irq_count;
309           unsigned long irq_posted;
310 #define ENGINE_IRQ_BREADCRUMB 0
311 #define ENGINE_IRQ_EXECLIST 1
312 
313           /* Rather than have every client wait upon all user interrupts,
314            * with the herd waking after every interrupt and each doing the
315            * heavyweight seqno dance, we delegate the task (of being the
316            * bottom-half of the user interrupt) to the first client. After
317            * every interrupt, we wake up one client, who does the heavyweight
318            * coherent seqno read and either goes back to sleep (if incomplete),
319            * or wakes up all the completed clients in parallel, before then
320            * transferring the bottom-half status to the next client in the queue.
321            *
322            * Compared to walking the entire list of waiters in a single dedicated
323            * bottom-half, we reduce the latency of the first waiter by avoiding
324            * a context switch, but incur additional coherent seqno reads when
325            * following the chain of request breadcrumbs. Since it is most likely
326            * that we have a single client waiting on each seqno, then reducing
327            * the overhead of waking that client is much preferred.
328            */
329           struct intel_breadcrumbs {
330                     spinlock_t irq_lock; /* protects irq_*; irqsafe */
331                     struct intel_wait *irq_wait; /* oldest waiter by retirement */
332 
333                     spinlock_t rb_lock; /* protects the rb and wraps irq_lock */
334                     struct rb_root waiters; /* sorted by retirement, priority */
335                     struct rb_root signals; /* sorted by retirement */
336                     struct task_struct *signaler; /* used for fence signalling */
337                     struct drm_i915_gem_request __rcu *first_signal;
338                     struct timer_list fake_irq; /* used after a missed interrupt */
339                     struct timer_list hangcheck; /* detect missed interrupts */
340 
341                     unsigned int hangcheck_interrupts;
342 
343                     bool irq_armed : 1;
344                     bool irq_enabled : 1;
345                     I915_SELFTEST_DECLARE(bool mock : 1);
346           } breadcrumbs;
347 
348           /*
349            * A pool of objects to use as shadow copies of client batch buffers
350            * when the command parser is enabled. Prevents the client from
351            * modifying the batch contents after software parsing.
352            */
353           struct i915_gem_batch_pool batch_pool;
354 
355           struct intel_hw_status_page status_page;
356           struct i915_ctx_workarounds wa_ctx;
357           struct i915_vma *scratch;
358 
359           u32             irq_keep_mask; /* always keep these interrupts */
360           u32                 irq_enable_mask; /* bitmask to enable ring interrupt */
361           void                (*irq_enable)(struct intel_engine_cs *engine);
362           void                (*irq_disable)(struct intel_engine_cs *engine);
363 
364           int                 (*init_hw)(struct intel_engine_cs *engine);
365           void                (*reset_hw)(struct intel_engine_cs *engine,
366                                             struct drm_i915_gem_request *req);
367 
368           void                (*set_default_submission)(struct intel_engine_cs *engine);
369 
370           struct intel_ring *(*context_pin)(struct intel_engine_cs *engine,
371                                                     struct i915_gem_context *ctx);
372           void                (*context_unpin)(struct intel_engine_cs *engine,
373                                                    struct i915_gem_context *ctx);
374           int                 (*request_alloc)(struct drm_i915_gem_request *req);
375           int                 (*init_context)(struct drm_i915_gem_request *req);
376 
377           int                 (*emit_flush)(struct drm_i915_gem_request *request,
378                                               u32 mode);
379 #define EMIT_INVALIDATE       BIT(0)
380 #define EMIT_FLUSH  BIT(1)
381 #define EMIT_BARRIER          (EMIT_INVALIDATE | EMIT_FLUSH)
382           int                 (*emit_bb_start)(struct drm_i915_gem_request *req,
383                                                    u64 offset, u32 length,
384                                                    unsigned int dispatch_flags);
385 #define I915_DISPATCH_SECURE BIT(0)
386 #define I915_DISPATCH_PINNED BIT(1)
387 #define I915_DISPATCH_RS     BIT(2)
388           void                (*emit_breadcrumb)(struct drm_i915_gem_request *req,
389                                                      u32 *cs);
390           int                 emit_breadcrumb_sz;
391 
392           /* Pass the request to the hardware queue (e.g. directly into
393            * the legacy ringbuffer or to the end of an execlist).
394            *
395            * This is called from an atomic context with irqs disabled; must
396            * be irq safe.
397            */
398           void                (*submit_request)(struct drm_i915_gem_request *req);
399 
400           /* Call when the priority on a request has changed and it and its
401            * dependencies may need rescheduling. Note the request itself may
402            * not be ready to run!
403            *
404            * Called under the struct_mutex.
405            */
406           void                (*schedule)(struct drm_i915_gem_request *request,
407                                             int priority);
408 
409           /*
410            * Cancel all requests on the hardware, or queued for execution.
411            * This should only cancel the ready requests that have been
412            * submitted to the engine (via the engine->submit_request callback).
413            * This is called when marking the device as wedged.
414            */
415           void                (*cancel_requests)(struct intel_engine_cs *engine);
416 
417           /* Some chipsets are not quite as coherent as advertised and need
418            * an expensive kick to force a true read of the up-to-date seqno.
419            * However, the up-to-date seqno is not always required and the last
420            * seen value is good enough. Note that the seqno will always be
421            * monotonic, even if not coherent.
422            */
423           void                (*irq_seqno_barrier)(struct intel_engine_cs *engine);
424           void                (*cleanup)(struct intel_engine_cs *engine);
425 
426           /* GEN8 signal/wait table - never trust comments!
427            *          signal to         signal to    signal to   signal to      signal to
428            *            RCS                VCS          BCS        VECS                    VCS2
429            *      --------------------------------------------------------------------
430            *  RCS | NOP (0x00) | VCS (0x08) | BCS (0x10) | VECS (0x18) | VCS2 (0x20) |
431            *        |-------------------------------------------------------------------
432            *  VCS | RCS (0x28) | NOP (0x30) | BCS (0x38) | VECS (0x40) | VCS2 (0x48) |
433            *        |-------------------------------------------------------------------
434            *  BCS | RCS (0x50) | VCS (0x58) | NOP (0x60) | VECS (0x68) | VCS2 (0x70) |
435            *        |-------------------------------------------------------------------
436            * VECS | RCS (0x78) | VCS (0x80) | BCS (0x88) |  NOP (0x90) | VCS2 (0x98) |
437            *        |-------------------------------------------------------------------
438            * VCS2 | RCS (0xa0) | VCS (0xa8) | BCS (0xb0) | VECS (0xb8) | NOP  (0xc0) |
439            *        |-------------------------------------------------------------------
440            *
441            * Generalization:
442            *  f(x, y) := (x->id * NUM_RINGS * seqno_size) + (seqno_size * y->id)
443            *  ie. transpose of g(x, y)
444            *
445            *         sync from          sync from    sync from    sync from     sync from
446            *            RCS                VCS          BCS        VECS                    VCS2
447            *      --------------------------------------------------------------------
448            *  RCS | NOP (0x00) | VCS (0x28) | BCS (0x50) | VECS (0x78) | VCS2 (0xa0) |
449            *        |-------------------------------------------------------------------
450            *  VCS | RCS (0x08) | NOP (0x30) | BCS (0x58) | VECS (0x80) | VCS2 (0xa8) |
451            *        |-------------------------------------------------------------------
452            *  BCS | RCS (0x10) | VCS (0x38) | NOP (0x60) | VECS (0x88) | VCS2 (0xb0) |
453            *        |-------------------------------------------------------------------
454            * VECS | RCS (0x18) | VCS (0x40) | BCS (0x68) |  NOP (0x90) | VCS2 (0xb8) |
455            *        |-------------------------------------------------------------------
456            * VCS2 | RCS (0x20) | VCS (0x48) | BCS (0x70) | VECS (0x98) |  NOP (0xc0) |
457            *        |-------------------------------------------------------------------
458            *
459            * Generalization:
460            *  g(x, y) := (y->id * NUM_RINGS * seqno_size) + (seqno_size * x->id)
461            *  ie. transpose of f(x, y)
462            */
463           struct {
464                     union {
465 #define GEN6_SEMAPHORE_LAST   VECS_HW
466 #define GEN6_NUM_SEMAPHORES   (GEN6_SEMAPHORE_LAST + 1)
467 #define GEN6_SEMAPHORES_MASK  GENMASK(GEN6_SEMAPHORE_LAST, 0)
468                               struct {
469                                         /* our mbox written by others */
470                                         u32                 wait[GEN6_NUM_SEMAPHORES];
471                                         /* mboxes this ring signals to */
472                                         i915_reg_t          signal[GEN6_NUM_SEMAPHORES];
473                               } mbox;
474                               u64                 signal_ggtt[I915_NUM_ENGINES];
475                     };
476 
477                     /* AKA wait() */
478                     int       (*sync_to)(struct drm_i915_gem_request *req,
479                                            struct drm_i915_gem_request *signal);
480                     u32       *(*signal)(struct drm_i915_gem_request *req, u32 *cs);
481           } semaphore;
482 
483           struct intel_engine_execlists execlists;
484 
485           /* Contexts are pinned whilst they are active on the GPU. The last
486            * context executed remains active whilst the GPU is idle - the
487            * switch away and write to the context object only occurs on the
488            * next execution.  Contexts are only unpinned on retirement of the
489            * following request ensuring that we can always write to the object
490            * on the context switch even after idling. Across suspend, we switch
491            * to the kernel context and trash it as the save may not happen
492            * before the hardware is powered down.
493            */
494           struct i915_gem_context *last_retired_context;
495 
496           /* We track the current MI_SET_CONTEXT in order to eliminate
497            * redudant context switches. This presumes that requests are not
498            * reordered! Or when they are the tracking is updated along with
499            * the emission of individual requests into the legacy command
500            * stream (ring).
501            */
502           struct i915_gem_context *legacy_active_context;
503 
504           /* status_notifier: list of callbacks for context-switch changes */
505           struct atomic_notifier_head context_status_notifier;
506 
507           struct intel_engine_hangcheck hangcheck;
508 
509           bool needs_cmd_parser;
510 
511           /*
512            * Table of commands the command parser needs to know about
513            * for this engine.
514            */
515           DECLARE_HASHTABLE(cmd_hash, I915_CMD_HASH_ORDER);
516 
517           /*
518            * Table of registers allowed in commands that read/write registers.
519            */
520           const struct drm_i915_reg_table *reg_tables;
521           int reg_table_count;
522 
523           /*
524            * Returns the bitmask for the length field of the specified command.
525            * Return 0 for an unrecognized/invalid command.
526            *
527            * If the command parser finds an entry for a command in the engine's
528            * cmd_tables, it gets the command's length based on the table entry.
529            * If not, it calls this function to determine the per-engine length
530            * field encoding for the command (i.e. different opcode ranges use
531            * certain bits to encode the command length in the header).
532            */
533           u32 (*get_cmd_length_mask)(u32 cmd_header);
534 };
535 
536 static inline void
execlists_set_active(struct intel_engine_execlists * execlists,unsigned int bit)537 execlists_set_active(struct intel_engine_execlists *execlists,
538                          unsigned int bit)
539 {
540           __set_bit(bit, (unsigned long *)&execlists->active);
541 }
542 
543 static inline void
execlists_clear_active(struct intel_engine_execlists * execlists,unsigned int bit)544 execlists_clear_active(struct intel_engine_execlists *execlists,
545                            unsigned int bit)
546 {
547           __clear_bit(bit, (unsigned long *)&execlists->active);
548 }
549 
550 static inline bool
execlists_is_active(const struct intel_engine_execlists * execlists,unsigned int bit)551 execlists_is_active(const struct intel_engine_execlists *execlists,
552                         unsigned int bit)
553 {
554           return test_bit(bit, (unsigned long *)&execlists->active);
555 }
556 
557 static inline unsigned int
execlists_num_ports(const struct intel_engine_execlists * const execlists)558 execlists_num_ports(const struct intel_engine_execlists * const execlists)
559 {
560           return execlists->port_mask + 1;
561 }
562 
563 static inline void
execlists_port_complete(struct intel_engine_execlists * const execlists,struct execlist_port * const port)564 execlists_port_complete(struct intel_engine_execlists * const execlists,
565                               struct execlist_port * const port)
566 {
567           const unsigned int m = execlists->port_mask;
568 
569           GEM_BUG_ON(port_index(port, execlists) != 0);
570           GEM_BUG_ON(!execlists_is_active(execlists, EXECLISTS_ACTIVE_USER));
571 
572           memmove(port, port + 1, m * sizeof(struct execlist_port));
573           memset(port + m, 0, sizeof(struct execlist_port));
574 }
575 
576 static inline unsigned int
intel_engine_flag(const struct intel_engine_cs * engine)577 intel_engine_flag(const struct intel_engine_cs *engine)
578 {
579           return BIT(engine->id);
580 }
581 
582 static inline u32
intel_read_status_page(struct intel_engine_cs * engine,int reg)583 intel_read_status_page(struct intel_engine_cs *engine, int reg)
584 {
585           /* Ensure that the compiler doesn't optimize away the load. */
586           return READ_ONCE(engine->status_page.page_addr[reg]);
587 }
588 
589 static inline void
intel_write_status_page(struct intel_engine_cs * engine,int reg,u32 value)590 intel_write_status_page(struct intel_engine_cs *engine, int reg, u32 value)
591 {
592           /* Writing into the status page should be done sparingly. Since
593            * we do when we are uncertain of the device state, we take a bit
594            * of extra paranoia to try and ensure that the HWS takes the value
595            * we give and that it doesn't end up trapped inside the CPU!
596            */
597           if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
598                     mb();
599                     linux_clflush(&engine->status_page.page_addr[reg]);
600                     engine->status_page.page_addr[reg] = value;
601                     linux_clflush(&engine->status_page.page_addr[reg]);
602                     mb();
603           } else {
604                     WRITE_ONCE(engine->status_page.page_addr[reg], value);
605           }
606 }
607 
608 /*
609  * Reads a dword out of the status page, which is written to from the command
610  * queue by automatic updates, MI_REPORT_HEAD, MI_STORE_DATA_INDEX, or
611  * MI_STORE_DATA_IMM.
612  *
613  * The following dwords have a reserved meaning:
614  * 0x00: ISR copy, updated when an ISR bit not set in the HWSTAM changes.
615  * 0x04: ring 0 head pointer
616  * 0x05: ring 1 head pointer (915-class)
617  * 0x06: ring 2 head pointer (915-class)
618  * 0x10-0x1b: Context status DWords (GM45)
619  * 0x1f: Last written status offset. (GM45)
620  * 0x20-0x2f: Reserved (Gen6+)
621  *
622  * The area from dword 0x30 to 0x3ff is available for driver usage.
623  */
624 #define I915_GEM_HWS_INDEX              0x30
625 #define I915_GEM_HWS_INDEX_ADDR (I915_GEM_HWS_INDEX << MI_STORE_DWORD_INDEX_SHIFT)
626 #define I915_GEM_HWS_SCRATCH_INDEX      0x40
627 #define I915_GEM_HWS_SCRATCH_ADDR (I915_GEM_HWS_SCRATCH_INDEX << MI_STORE_DWORD_INDEX_SHIFT)
628 
629 #define I915_HWS_CSB_BUF0_INDEX                   0x10
630 #define I915_HWS_CSB_WRITE_INDEX        0x1f
631 #define CNL_HWS_CSB_WRITE_INDEX                   0x2f
632 
633 struct intel_ring *
634 intel_engine_create_ring(struct intel_engine_cs *engine, int size);
635 int intel_ring_pin(struct intel_ring *ring,
636                        struct drm_i915_private *i915,
637                        unsigned int offset_bias);
638 void intel_ring_reset(struct intel_ring *ring, u32 tail);
639 unsigned int intel_ring_update_space(struct intel_ring *ring);
640 void intel_ring_unpin(struct intel_ring *ring);
641 void intel_ring_free(struct intel_ring *ring);
642 
643 void intel_engine_stop(struct intel_engine_cs *engine);
644 void intel_engine_cleanup(struct intel_engine_cs *engine);
645 
646 void intel_legacy_submission_resume(struct drm_i915_private *dev_priv);
647 
648 int __must_check intel_ring_cacheline_align(struct drm_i915_gem_request *req);
649 
650 u32 __must_check *intel_ring_begin(struct drm_i915_gem_request *req,
651                                            unsigned int n);
652 
653 static inline void
intel_ring_advance(struct drm_i915_gem_request * req,u32 * cs)654 intel_ring_advance(struct drm_i915_gem_request *req, u32 *cs)
655 {
656           /* Dummy function.
657            *
658            * This serves as a placeholder in the code so that the reader
659            * can compare against the preceding intel_ring_begin() and
660            * check that the number of dwords emitted matches the space
661            * reserved for the command packet (i.e. the value passed to
662            * intel_ring_begin()).
663            */
664           GEM_BUG_ON((req->ring->vaddr + req->ring->emit) != cs);
665 }
666 
667 static inline u32
intel_ring_wrap(const struct intel_ring * ring,u32 pos)668 intel_ring_wrap(const struct intel_ring *ring, u32 pos)
669 {
670           return pos & (ring->size - 1);
671 }
672 
673 static inline u32
intel_ring_offset(const struct drm_i915_gem_request * req,void * addr)674 intel_ring_offset(const struct drm_i915_gem_request *req, void *addr)
675 {
676           /* Don't write ring->size (equivalent to 0) as that hangs some GPUs. */
677           u32 offset = addr - req->ring->vaddr;
678           GEM_BUG_ON(offset > req->ring->size);
679           return intel_ring_wrap(req->ring, offset);
680 }
681 
682 static inline void
assert_ring_tail_valid(const struct intel_ring * ring,unsigned int tail)683 assert_ring_tail_valid(const struct intel_ring *ring, unsigned int tail)
684 {
685           /* We could combine these into a single tail operation, but keeping
686            * them as seperate tests will help identify the cause should one
687            * ever fire.
688            */
689           GEM_BUG_ON(!IS_ALIGNED(tail, 8));
690           GEM_BUG_ON(tail >= ring->size);
691 
692           /*
693            * "Ring Buffer Use"
694            *        Gen2 BSpec "1. Programming Environment" / 1.4.4.6
695            *        Gen3 BSpec "1c Memory Interface Functions" / 2.3.4.5
696            *        Gen4+ BSpec "1c Memory Interface and Command Stream" / 5.3.4.5
697            * "If the Ring Buffer Head Pointer and the Tail Pointer are on the
698            * same cacheline, the Head Pointer must not be greater than the Tail
699            * Pointer."
700            *
701            * We use ring->head as the last known location of the actual RING_HEAD,
702            * it may have advanced but in the worst case it is equally the same
703            * as ring->head and so we should never program RING_TAIL to advance
704            * into the same cacheline as ring->head.
705            */
706 #define cacheline(a) round_down(a, CACHELINE_BYTES)
707           GEM_BUG_ON(cacheline(tail) == cacheline(ring->head) &&
708                        tail < ring->head);
709 #undef cacheline
710 }
711 
712 static inline unsigned int
intel_ring_set_tail(struct intel_ring * ring,unsigned int tail)713 intel_ring_set_tail(struct intel_ring *ring, unsigned int tail)
714 {
715           /* Whilst writes to the tail are strictly order, there is no
716            * serialisation between readers and the writers. The tail may be
717            * read by i915_gem_request_retire() just as it is being updated
718            * by execlists, as although the breadcrumb is complete, the context
719            * switch hasn't been seen.
720            */
721           assert_ring_tail_valid(ring, tail);
722           ring->tail = tail;
723           return tail;
724 }
725 
726 void intel_engine_init_global_seqno(struct intel_engine_cs *engine, u32 seqno);
727 
728 void intel_engine_setup_common(struct intel_engine_cs *engine);
729 int intel_engine_init_common(struct intel_engine_cs *engine);
730 int intel_engine_create_scratch(struct intel_engine_cs *engine, int size);
731 void intel_engine_cleanup_common(struct intel_engine_cs *engine);
732 
733 int intel_init_render_ring_buffer(struct intel_engine_cs *engine);
734 int intel_init_bsd_ring_buffer(struct intel_engine_cs *engine);
735 int intel_init_blt_ring_buffer(struct intel_engine_cs *engine);
736 int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine);
737 
738 u64 intel_engine_get_active_head(struct intel_engine_cs *engine);
739 u64 intel_engine_get_last_batch_head(struct intel_engine_cs *engine);
740 
intel_engine_get_seqno(struct intel_engine_cs * engine)741 static inline u32 intel_engine_get_seqno(struct intel_engine_cs *engine)
742 {
743           return intel_read_status_page(engine, I915_GEM_HWS_INDEX);
744 }
745 
intel_engine_last_submit(struct intel_engine_cs * engine)746 static inline u32 intel_engine_last_submit(struct intel_engine_cs *engine)
747 {
748           /* We are only peeking at the tail of the submit queue (and not the
749            * queue itself) in order to gain a hint as to the current active
750            * state of the engine. Callers are not expected to be taking
751            * engine->timeline->lock, nor are they expected to be concerned
752            * wtih serialising this hint with anything, so document it as
753            * a hint and nothing more.
754            */
755           return READ_ONCE(engine->timeline->seqno);
756 }
757 
758 int init_workarounds_ring(struct intel_engine_cs *engine);
759 int intel_ring_workarounds_emit(struct drm_i915_gem_request *req);
760 
761 void intel_engine_get_instdone(struct intel_engine_cs *engine,
762                                      struct intel_instdone *instdone);
763 
764 /*
765  * Arbitrary size for largest possible 'add request' sequence. The code paths
766  * are complex and variable. Empirical measurement shows that the worst case
767  * is BDW at 192 bytes (6 + 6 + 36 dwords), then ILK at 136 bytes. However,
768  * we need to allocate double the largest single packet within that emission
769  * to account for tail wraparound (so 6 + 6 + 72 dwords for BDW).
770  */
771 #define MIN_SPACE_FOR_ADD_REQUEST 336
772 
intel_hws_seqno_address(struct intel_engine_cs * engine)773 static inline u32 intel_hws_seqno_address(struct intel_engine_cs *engine)
774 {
775           return engine->status_page.ggtt_offset + I915_GEM_HWS_INDEX_ADDR;
776 }
777 
778 /* intel_breadcrumbs.c -- user interrupt bottom-half for waiters */
779 int intel_engine_init_breadcrumbs(struct intel_engine_cs *engine);
780 
intel_wait_init(struct intel_wait * wait,struct drm_i915_gem_request * rq)781 static inline void intel_wait_init(struct intel_wait *wait,
782                                            struct drm_i915_gem_request *rq)
783 {
784           wait->tsk = current;
785           wait->request = rq;
786 }
787 
intel_wait_init_for_seqno(struct intel_wait * wait,u32 seqno)788 static inline void intel_wait_init_for_seqno(struct intel_wait *wait, u32 seqno)
789 {
790           wait->tsk = current;
791           wait->seqno = seqno;
792 }
793 
intel_wait_has_seqno(const struct intel_wait * wait)794 static inline bool intel_wait_has_seqno(const struct intel_wait *wait)
795 {
796           return wait->seqno;
797 }
798 
799 static inline bool
intel_wait_update_seqno(struct intel_wait * wait,u32 seqno)800 intel_wait_update_seqno(struct intel_wait *wait, u32 seqno)
801 {
802           wait->seqno = seqno;
803           return intel_wait_has_seqno(wait);
804 }
805 
806 static inline bool
intel_wait_update_request(struct intel_wait * wait,const struct drm_i915_gem_request * rq)807 intel_wait_update_request(struct intel_wait *wait,
808                                 const struct drm_i915_gem_request *rq)
809 {
810           return intel_wait_update_seqno(wait, i915_gem_request_global_seqno(rq));
811 }
812 
813 static inline bool
intel_wait_check_seqno(const struct intel_wait * wait,u32 seqno)814 intel_wait_check_seqno(const struct intel_wait *wait, u32 seqno)
815 {
816           return wait->seqno == seqno;
817 }
818 
819 static inline bool
intel_wait_check_request(const struct intel_wait * wait,const struct drm_i915_gem_request * rq)820 intel_wait_check_request(const struct intel_wait *wait,
821                                const struct drm_i915_gem_request *rq)
822 {
823           return intel_wait_check_seqno(wait, i915_gem_request_global_seqno(rq));
824 }
825 
intel_wait_complete(const struct intel_wait * wait)826 static inline bool intel_wait_complete(const struct intel_wait *wait)
827 {
828           return RB_EMPTY_NODE(&wait->node);
829 }
830 
831 bool intel_engine_add_wait(struct intel_engine_cs *engine,
832                                  struct intel_wait *wait);
833 void intel_engine_remove_wait(struct intel_engine_cs *engine,
834                                     struct intel_wait *wait);
835 void intel_engine_enable_signaling(struct drm_i915_gem_request *request,
836                                            bool wakeup);
837 void intel_engine_cancel_signaling(struct drm_i915_gem_request *request);
838 
intel_engine_has_waiter(const struct intel_engine_cs * engine)839 static inline bool intel_engine_has_waiter(const struct intel_engine_cs *engine)
840 {
841           return READ_ONCE(engine->breadcrumbs.irq_wait);
842 }
843 
844 unsigned int intel_engine_wakeup(struct intel_engine_cs *engine);
845 #define ENGINE_WAKEUP_WAITER BIT(0)
846 #define ENGINE_WAKEUP_ASLEEP BIT(1)
847 
848 void __intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);
849 void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);
850 
851 void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine);
852 void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine);
853 bool intel_breadcrumbs_busy(struct intel_engine_cs *engine);
854 
gen8_emit_pipe_control(u32 * batch,u32 flags,u32 offset)855 static inline u32 *gen8_emit_pipe_control(u32 *batch, u32 flags, u32 offset)
856 {
857           memset(batch, 0, 6 * sizeof(u32));
858 
859           batch[0] = GFX_OP_PIPE_CONTROL(6);
860           batch[1] = flags;
861           batch[2] = offset;
862 
863           return batch + 6;
864 }
865 
866 bool intel_engine_is_idle(struct intel_engine_cs *engine);
867 bool intel_engines_are_idle(struct drm_i915_private *dev_priv);
868 
869 void intel_engines_mark_idle(struct drm_i915_private *i915);
870 void intel_engines_reset_default_submission(struct drm_i915_private *i915);
871 
872 bool intel_engine_can_store_dword(struct intel_engine_cs *engine);
873 
874 void intel_engine_dump(struct intel_engine_cs *engine, struct drm_printer *p);
875 
876 #endif /* _INTEL_RINGBUFFER_H_ */
877