xref: /haiku/src/add-ons/accelerants/radeon/EngineManagment.c (revision 2b76973fa2401f7a5edf68e6470f3d3210cbcff3)
1 /*
2 	Copyright (c) 2002, Thomas Kurschel
3 
4 
5 	Part of Radeon accelerant
6 
7 	Hardware accelerator management
8 
9 	All accelerator commands go through the following steps:
10 	- accelerant adds command to CP buffer and updates CP write pointer
11 	- CP fetches command and sends it to MicroController
12 	- MicroController instructs 2D unit to execute command
13 	- 2D unit draws into 2D Destination Cache (DC)
14 	- 2D Destination Cache is drained to frame buffer
15 
16 	Whenever a token is required by BeOS, a command is queued to write
17 	the timestamp into Scratch Register 0. I haven't fully understand
18 	when and how coherancy is assured by Radeon, so I assume the following:
19 	- when the timestamp is written, all previous commands have been issued,
20 	  i.e. they are read and executed by the microcontroller
21 	- to make sure previously issued 2D commands have been finished,
22 	  a WAIT_2D_IDLECLEAN command is inserted before the scratch register
23 	  write
24 	- to flush the destination cache, a RB2D_DC_FLUSH_ALL command is
25 	  issued before the wait; I hope that the wait command also waits for
26 	  the flush command, but I'm not sure about that
27 
28 	Remains the cache coherency problem. It you can set various bits in
29 	DSTCACHE_MODE register to assure that, but first I don't really understand
30 	them, and second I'm not sure which other caches/FIFO may make trouble.
31 	Especially, Be wants to use CPU and CP accesses in parallel. Hopefully,
32 	they don't interfere.
33 
34 	I know that the PAINT_MULTI commands makes trouble if you change the
35 	ROP to something else: CPU writes produce garbage in frame buffer for the
36 	next couple of accesses. Resetting the ROP to a simply copy helps, but
37 	I'm not sure what happens with concurrent CPU accesses to other areas
38 	of the frame buffer.
39 */
40 
41 
42 #include "radeon_accelerant.h"
43 #include "generic.h"
44 #include "rbbm_regs.h"
45 #include "GlobalData.h"
46 #include "mmio.h"
47 #include "CP.h"
48 
49 static engine_token radeon_engine_token = { 1, B_2D_ACCELERATION, NULL };
50 
51 // public function: return number of hardware engine
52 uint32 ACCELERANT_ENGINE_COUNT(void)
53 {
54 	// hm, is there *any* card sporting more then
55 	// one hardware accelerator???
56 	return 1;
57 }
58 
59 // write current sync token into CP stream;
60 // we instruct the CP to flush all kind of cache first to not interfere
61 // with subsequent host writes
62 static void writeSyncToken( accelerator_info *ai )
63 {
64 	// don't write token if it hasn't changed since last write
65 	if( ai->si->engine.count == ai->si->engine.written )
66 		return;
67 
68 	if( ai->si->acc_dma ) {
69 		START_IB();
70 
71 		// flush pending data
72 		WRITE_IB_REG( RADEON_RB2D_DSTCACHE_CTLSTAT, RADEON_RB2D_DC_FLUSH_ALL );
73 
74 		// make sure commands are finished
75 		WRITE_IB_REG( RADEON_WAIT_UNTIL, RADEON_WAIT_2D_IDLECLEAN |
76 			RADEON_WAIT_3D_IDLECLEAN | RADEON_WAIT_HOST_IDLECLEAN );
77 
78 		// write scratch register
79 		WRITE_IB_REG( RADEON_SCRATCH_REG0, ai->si->engine.count );
80 
81 		ai->si->engine.written = ai->si->engine.count;
82 
83 		SUBMIT_IB();
84 	} else {
85 		Radeon_WaitForFifo( ai, 2 );
86 		OUTREG( ai->regs, RADEON_RB2D_DSTCACHE_CTLSTAT, RADEON_RB2D_DC_FLUSH_ALL);
87 		OUTREG( ai->regs, RADEON_WAIT_UNTIL, RADEON_WAIT_2D_IDLECLEAN |
88 		   RADEON_WAIT_3D_IDLECLEAN |
89 		   RADEON_WAIT_HOST_IDLECLEAN);
90 		ai->si->engine.written = ai->si->engine.count;
91 	}
92 }
93 
94 // public function: acquire engine for future use
95 //	capabilites - required 2D/3D capabilities of engine, ignored
96 //	max_wait - maximum time we want to wait (in ms?), ignored
97 //	st - when engine has been acquired, wait for this sync token
98 //	et - (out) specifier of the engine acquired
99 status_t ACQUIRE_ENGINE( uint32 capabilities, uint32 max_wait,
100 	sync_token *st, engine_token **et )
101 {
102 	shared_info *si = ai->si;
103 
104 	SHOW_FLOW0( 4, "" );
105 
106 	(void)capabilities;
107 	(void)max_wait;
108 
109 	ACQUIRE_BEN( si->engine.lock)
110 
111 	// wait for sync
112 	if (st)
113 		SYNC_TO_TOKEN( st );
114 
115 	*et = &radeon_engine_token;
116 	return B_OK;
117 }
118 
119 // public function: release accelerator
120 //	et - engine to release
121 //	st - (out) sync token to be filled out
122 status_t RELEASE_ENGINE( engine_token *et, sync_token *st )
123 {
124 	shared_info *si = ai->si;
125 
126 	SHOW_FLOW0( 4, "" );
127 
128 	// fill out sync token
129 	if (st) {
130 		writeSyncToken( ai );
131 
132 		st->engine_id = et->engine_id;
133 		st->counter = si->engine.count;
134 	}
135 
136 	RELEASE_BEN( ai->si->engine.lock )
137 
138 	return B_OK;
139 }
140 
141 // public function: wait until engine is idle
142 // ??? which engine to wait for? Is there anyone using this function?
143 //     is lock hold?
144 void WAIT_ENGINE_IDLE(void)
145 {
146 	SHOW_FLOW0( 4, "" );
147 
148 	Radeon_WaitForIdle( ai, false );
149 }
150 
151 // public function: get sync token
152 //	et - engine to wait for
153 //	st - (out) sync token to be filled out
154 status_t GET_SYNC_TOKEN( engine_token *et, sync_token *st )
155 {
156 	shared_info *si = ai->si;
157 
158 	SHOW_FLOW0( 4, "" );
159 
160 	writeSyncToken( ai );
161 
162 	st->engine_id = et->engine_id;
163 	st->counter = si->engine.count;
164 
165 	SHOW_FLOW( 4, "got counter=%d", si->engine.count );
166 
167 	return B_OK;
168 }
169 
170 // this is the same as the corresponding kernel function
171 void Radeon_Spin( uint32 delay )
172 {
173 	bigtime_t start_time;
174 
175 	start_time = system_time();
176 
177 	while( system_time() - start_time < delay )
178 		;
179 }
180 
181 // public: sync to token
182 //	st - token to wait for
183 status_t SYNC_TO_TOKEN( sync_token *st )
184 {
185 	shared_info *si = ai->si;
186 	bigtime_t start_time, sample_time;
187 
188 	SHOW_FLOW0( 4, "" );
189 
190 	if ( !ai->si->acc_dma )
191 	{
192 		Radeon_WaitForFifo( ai, 64 );
193 		Radeon_WaitForIdle( ai, false );
194 		return B_OK;
195 	}
196 
197 	start_time = system_time();
198 
199 	while( 1 ) {
200 		SHOW_FLOW( 4, "passed counter=%d",
201 			((uint32 *)(ai->mapped_memory[si->cp.feedback.mem_type].data + si->cp.feedback.scratch_mem_offset))[0] );
202 			//si->cp.scratch.ptr[0] );
203 
204 		// a bit nasty: counter is 64 bit, but we have 32 bit only,
205 		// this is a tricky calculation to handle wrap-arounds correctly
206 		if( (int32)(
207 			((uint32 *)(ai->mapped_memory[si->cp.feedback.mem_type].data + si->cp.feedback.scratch_mem_offset))[0]
208 			//si->cp.scratch.ptr[0]
209 			- st->counter) >= 0 )
210 			return B_OK;
211 		/*if( (int32)(INREG( ai->regs, RADEON_SCRATCH_REG0 ) - st->counter) >= 0 )
212 			return B_OK;*/
213 
214 		// commands have not been finished;
215 		// this is a good time to free completed buffers as we have to
216 		// busy-wait anyway
217 		ACQUIRE_BEN( si->cp.lock );
218 		Radeon_FreeIndirectBuffers( ai );
219 		RELEASE_BEN( si->cp.lock );
220 
221 		sample_time = system_time();
222 
223 		if( sample_time - start_time > 100000 )
224 			break;
225 
226 		// use exponential fall-off
227 		// in the beginning do busy-waiting, later on we let thread sleep
228 		// the micro-spin is used to reduce PCI load
229 		if( sample_time - start_time > 5000 )
230 			snooze( (sample_time - start_time) / 10 );
231 		else
232 			Radeon_Spin( 1 );
233 	}
234 
235 	// we could reset engine now, but caller doesn't need to acquire
236 	// engine before calling this function, so we either reset it
237 	// without sync (ouch!) or acquire engine first and risk deadlocking
238 	SHOW_ERROR( 0, "Failed waiting for token %d (active token: %d)",
239 		st->counter, /*INREG( ai->regs, RADEON_SCRATCH_REG0 )*/
240 		((uint32 *)(ai->mapped_memory[si->cp.feedback.mem_type].data + si->cp.feedback.scratch_mem_offset))[0] );
241 		//si->cp.scratch.ptr[0] );
242 
243 	Radeon_ResetEngine( ai );
244 
245 	return B_ERROR;
246 }
247