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git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - arch/powerpc/platforms/cell/spufs/spu_restore.c
4 * (C) Copyright IBM Corp. 2005
6 * SPU-side context restore sequence outlined in
7 * Synergistic Processor Element Book IV
9 * Author: Mark Nutter <mnutter@us.ibm.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2, or (at your option)
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #define LS_SIZE 0x40000 /* 256K (in bytes) */
32 typedef unsigned int u32
;
33 typedef unsigned long long u64
;
35 #include <spu_intrinsics.h>
36 #include <asm/spu_csa.h>
37 #include "spu_utils.h"
39 #define BR_INSTR 0x327fff80 /* br -4 */
40 #define NOP_INSTR 0x40200000 /* nop */
41 #define HEQ_INSTR 0x7b000000 /* heq $0, $0 */
42 #define STOP_INSTR 0x00000000 /* stop 0x0 */
43 #define ILLEGAL_INSTR 0x00800000 /* illegal instr */
44 #define RESTORE_COMPLETE 0x00003ffc /* stop 0x3ffc */
46 static inline void fetch_regs_from_mem(addr64 lscsa_ea
)
48 unsigned int ls
= (unsigned int)®s_spill
[0];
49 unsigned int size
= sizeof(regs_spill
);
50 unsigned int tag_id
= 0;
51 unsigned int cmd
= 0x40; /* GET */
53 spu_writech(MFC_LSA
, ls
);
54 spu_writech(MFC_EAH
, lscsa_ea
.ui
[0]);
55 spu_writech(MFC_EAL
, lscsa_ea
.ui
[1]);
56 spu_writech(MFC_Size
, size
);
57 spu_writech(MFC_TagID
, tag_id
);
58 spu_writech(MFC_Cmd
, cmd
);
61 static inline void restore_upper_240kb(addr64 lscsa_ea
)
63 unsigned int ls
= 16384;
64 unsigned int list
= (unsigned int)&dma_list
[0];
65 unsigned int size
= sizeof(dma_list
);
66 unsigned int tag_id
= 0;
67 unsigned int cmd
= 0x44; /* GETL */
70 * Enqueue the GETL command (tag 0) to the MFC SPU command
71 * queue to transfer the upper 240 kb of LS from CSA.
73 spu_writech(MFC_LSA
, ls
);
74 spu_writech(MFC_EAH
, lscsa_ea
.ui
[0]);
75 spu_writech(MFC_EAL
, list
);
76 spu_writech(MFC_Size
, size
);
77 spu_writech(MFC_TagID
, tag_id
);
78 spu_writech(MFC_Cmd
, cmd
);
81 static inline void restore_decr(void)
84 unsigned int decr_running
;
87 /* Restore, Step 6(moved):
88 * If the LSCSA "decrementer running" flag is set
89 * then write the SPU_WrDec channel with the
90 * decrementer value from LSCSA.
92 offset
= LSCSA_QW_OFFSET(decr_status
);
93 decr_running
= regs_spill
[offset
].slot
[0] & SPU_DECR_STATUS_RUNNING
;
95 offset
= LSCSA_QW_OFFSET(decr
);
96 decr
= regs_spill
[offset
].slot
[0];
97 spu_writech(SPU_WrDec
, decr
);
101 static inline void write_ppu_mb(void)
107 * Write the MFC_WrOut_MB channel with the PPU_MB
110 offset
= LSCSA_QW_OFFSET(ppu_mb
);
111 data
= regs_spill
[offset
].slot
[0];
112 spu_writech(SPU_WrOutMbox
, data
);
115 static inline void write_ppuint_mb(void)
121 * Write the MFC_WrInt_MB channel with the PPUINT_MB
124 offset
= LSCSA_QW_OFFSET(ppuint_mb
);
125 data
= regs_spill
[offset
].slot
[0];
126 spu_writech(SPU_WrOutIntrMbox
, data
);
129 static inline void restore_fpcr(void)
132 vector
unsigned int fpcr
;
135 * Restore the floating-point status and control
136 * register from the LSCSA.
138 offset
= LSCSA_QW_OFFSET(fpcr
);
139 fpcr
= regs_spill
[offset
].v
;
143 static inline void restore_srr0(void)
149 * Restore the SPU SRR0 data from the LSCSA.
151 offset
= LSCSA_QW_OFFSET(srr0
);
152 srr0
= regs_spill
[offset
].slot
[0];
153 spu_writech(SPU_WrSRR0
, srr0
);
156 static inline void restore_event_mask(void)
159 unsigned int event_mask
;
162 * Restore the SPU_RdEventMsk data from the LSCSA.
164 offset
= LSCSA_QW_OFFSET(event_mask
);
165 event_mask
= regs_spill
[offset
].slot
[0];
166 spu_writech(SPU_WrEventMask
, event_mask
);
169 static inline void restore_tag_mask(void)
172 unsigned int tag_mask
;
175 * Restore the SPU_RdTagMsk data from the LSCSA.
177 offset
= LSCSA_QW_OFFSET(tag_mask
);
178 tag_mask
= regs_spill
[offset
].slot
[0];
179 spu_writech(MFC_WrTagMask
, tag_mask
);
182 static inline void restore_complete(void)
184 extern void exit_fini(void);
185 unsigned int *exit_instrs
= (unsigned int *)exit_fini
;
187 unsigned int stopped_status
;
188 unsigned int stopped_code
;
191 * Issue a stop-and-signal instruction with
192 * "good context restore" signal value.
195 * There may be additional instructions placed
196 * here by the PPE Sequence for SPU Context
197 * Restore in order to restore the correct
200 * This step is handled here by analyzing the
201 * LSCSA.stopped_status and then modifying the
202 * exit() function to behave appropriately.
205 offset
= LSCSA_QW_OFFSET(stopped_status
);
206 stopped_status
= regs_spill
[offset
].slot
[0];
207 stopped_code
= regs_spill
[offset
].slot
[1];
209 switch (stopped_status
) {
210 case SPU_STOPPED_STATUS_P_I
:
211 /* SPU_Status[P,I]=1. Add illegal instruction
212 * followed by stop-and-signal instruction after
213 * end of restore code.
215 exit_instrs
[0] = RESTORE_COMPLETE
;
216 exit_instrs
[1] = ILLEGAL_INSTR
;
217 exit_instrs
[2] = STOP_INSTR
| stopped_code
;
219 case SPU_STOPPED_STATUS_P_H
:
220 /* SPU_Status[P,H]=1. Add 'heq $0, $0' followed
221 * by stop-and-signal instruction after end of
224 exit_instrs
[0] = RESTORE_COMPLETE
;
225 exit_instrs
[1] = HEQ_INSTR
;
226 exit_instrs
[2] = STOP_INSTR
| stopped_code
;
228 case SPU_STOPPED_STATUS_S_P
:
229 /* SPU_Status[S,P]=1. Add nop instruction
230 * followed by 'br -4' after end of restore
233 exit_instrs
[0] = RESTORE_COMPLETE
;
234 exit_instrs
[1] = STOP_INSTR
| stopped_code
;
235 exit_instrs
[2] = NOP_INSTR
;
236 exit_instrs
[3] = BR_INSTR
;
238 case SPU_STOPPED_STATUS_S_I
:
239 /* SPU_Status[S,I]=1. Add illegal instruction
240 * followed by 'br -4' after end of restore code.
242 exit_instrs
[0] = RESTORE_COMPLETE
;
243 exit_instrs
[1] = ILLEGAL_INSTR
;
244 exit_instrs
[2] = NOP_INSTR
;
245 exit_instrs
[3] = BR_INSTR
;
247 case SPU_STOPPED_STATUS_I
:
248 /* SPU_Status[I]=1. Add illegal instruction followed
249 * by infinite loop after end of restore sequence.
251 exit_instrs
[0] = RESTORE_COMPLETE
;
252 exit_instrs
[1] = ILLEGAL_INSTR
;
253 exit_instrs
[2] = NOP_INSTR
;
254 exit_instrs
[3] = BR_INSTR
;
256 case SPU_STOPPED_STATUS_S
:
257 /* SPU_Status[S]=1. Add two 'nop' instructions. */
258 exit_instrs
[0] = RESTORE_COMPLETE
;
259 exit_instrs
[1] = NOP_INSTR
;
260 exit_instrs
[2] = NOP_INSTR
;
261 exit_instrs
[3] = BR_INSTR
;
263 case SPU_STOPPED_STATUS_H
:
264 /* SPU_Status[H]=1. Add 'heq $0, $0' instruction
265 * after end of restore code.
267 exit_instrs
[0] = RESTORE_COMPLETE
;
268 exit_instrs
[1] = HEQ_INSTR
;
269 exit_instrs
[2] = NOP_INSTR
;
270 exit_instrs
[3] = BR_INSTR
;
272 case SPU_STOPPED_STATUS_P
:
273 /* SPU_Status[P]=1. Add stop-and-signal instruction
274 * after end of restore code.
276 exit_instrs
[0] = RESTORE_COMPLETE
;
277 exit_instrs
[1] = STOP_INSTR
| stopped_code
;
279 case SPU_STOPPED_STATUS_R
:
280 /* SPU_Status[I,S,H,P,R]=0. Add infinite loop. */
281 exit_instrs
[0] = RESTORE_COMPLETE
;
282 exit_instrs
[1] = NOP_INSTR
;
283 exit_instrs
[2] = NOP_INSTR
;
284 exit_instrs
[3] = BR_INSTR
;
287 /* SPU_Status[R]=1. No additional instructions. */
294 * main - entry point for SPU-side context restore.
296 * This code deviates from the documented sequence in the
299 * 1. The EA for LSCSA is passed from PPE in the
300 * signal notification channels.
301 * 2. The register spill area is pulled by SPU
302 * into LS, rather than pushed by PPE.
303 * 3. All 128 registers are restored by exit().
304 * 4. The exit() function is modified at run
305 * time in order to properly restore the
306 * SPU_Status register.
312 lscsa_ea
.ui
[0] = spu_readch(SPU_RdSigNotify1
);
313 lscsa_ea
.ui
[1] = spu_readch(SPU_RdSigNotify2
);
314 fetch_regs_from_mem(lscsa_ea
);
316 set_event_mask(); /* Step 1. */
317 set_tag_mask(); /* Step 2. */
318 build_dma_list(lscsa_ea
); /* Step 3. */
319 restore_upper_240kb(lscsa_ea
); /* Step 4. */
320 /* Step 5: done by 'exit'. */
321 enqueue_putllc(lscsa_ea
); /* Step 7. */
322 set_tag_update(); /* Step 8. */
323 read_tag_status(); /* Step 9. */
324 restore_decr(); /* moved Step 6. */
325 read_llar_status(); /* Step 10. */
326 write_ppu_mb(); /* Step 11. */
327 write_ppuint_mb(); /* Step 12. */
328 restore_fpcr(); /* Step 13. */
329 restore_srr0(); /* Step 14. */
330 restore_event_mask(); /* Step 15. */
331 restore_tag_mask(); /* Step 16. */
332 /* Step 17. done by 'exit'. */
333 restore_complete(); /* Step 18. */