xref: /openbmc/qemu/target/ppc/timebase_helper.c (revision 34cc54fb)
1 /*
2  *  PowerPC emulation helpers for QEMU.
3  *
4  *  Copyright (c) 2003-2007 Jocelyn Mayer
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #include "qemu/osdep.h"
20 #include "cpu.h"
21 #include "hw/ppc/ppc.h"
22 #include "exec/helper-proto.h"
23 #include "exec/exec-all.h"
24 #include "qemu/log.h"
25 #include "qemu/main-loop.h"
26 
27 /*****************************************************************************/
28 /* SPR accesses */
29 
30 target_ulong helper_load_tbl(CPUPPCState *env)
31 {
32     return (target_ulong)cpu_ppc_load_tbl(env);
33 }
34 
35 target_ulong helper_load_tbu(CPUPPCState *env)
36 {
37     return cpu_ppc_load_tbu(env);
38 }
39 
40 target_ulong helper_load_atbl(CPUPPCState *env)
41 {
42     return (target_ulong)cpu_ppc_load_atbl(env);
43 }
44 
45 target_ulong helper_load_atbu(CPUPPCState *env)
46 {
47     return cpu_ppc_load_atbu(env);
48 }
49 
50 target_ulong helper_load_vtb(CPUPPCState *env)
51 {
52     return cpu_ppc_load_vtb(env);
53 }
54 
55 #if defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY)
56 target_ulong helper_load_purr(CPUPPCState *env)
57 {
58     return (target_ulong)cpu_ppc_load_purr(env);
59 }
60 
61 void helper_store_purr(CPUPPCState *env, target_ulong val)
62 {
63     CPUState *cs = env_cpu(env);
64     CPUState *ccs;
65     uint32_t nr_threads = cs->nr_threads;
66 
67     if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
68         cpu_ppc_store_purr(env, val);
69         return;
70     }
71 
72     THREAD_SIBLING_FOREACH(cs, ccs) {
73         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
74         cpu_ppc_store_purr(cenv, val);
75     }
76 }
77 #endif
78 
79 #if !defined(CONFIG_USER_ONLY)
80 void helper_store_tbl(CPUPPCState *env, target_ulong val)
81 {
82     CPUState *cs = env_cpu(env);
83     CPUState *ccs;
84     uint32_t nr_threads = cs->nr_threads;
85 
86     if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
87         cpu_ppc_store_tbl(env, val);
88         return;
89     }
90 
91     THREAD_SIBLING_FOREACH(cs, ccs) {
92         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
93         cpu_ppc_store_tbl(cenv, val);
94     }
95 }
96 
97 void helper_store_tbu(CPUPPCState *env, target_ulong val)
98 {
99     CPUState *cs = env_cpu(env);
100     CPUState *ccs;
101     uint32_t nr_threads = cs->nr_threads;
102 
103     if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
104         cpu_ppc_store_tbu(env, val);
105         return;
106     }
107 
108     THREAD_SIBLING_FOREACH(cs, ccs) {
109         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
110         cpu_ppc_store_tbu(cenv, val);
111     }
112 }
113 
114 void helper_store_atbl(CPUPPCState *env, target_ulong val)
115 {
116     cpu_ppc_store_atbl(env, val);
117 }
118 
119 void helper_store_atbu(CPUPPCState *env, target_ulong val)
120 {
121     cpu_ppc_store_atbu(env, val);
122 }
123 
124 target_ulong helper_load_decr(CPUPPCState *env)
125 {
126     return cpu_ppc_load_decr(env);
127 }
128 
129 void helper_store_decr(CPUPPCState *env, target_ulong val)
130 {
131     cpu_ppc_store_decr(env, val);
132 }
133 
134 target_ulong helper_load_hdecr(CPUPPCState *env)
135 {
136     return cpu_ppc_load_hdecr(env);
137 }
138 
139 void helper_store_hdecr(CPUPPCState *env, target_ulong val)
140 {
141     CPUState *cs = env_cpu(env);
142     CPUState *ccs;
143     uint32_t nr_threads = cs->nr_threads;
144 
145     if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
146         cpu_ppc_store_hdecr(env, val);
147         return;
148     }
149 
150     THREAD_SIBLING_FOREACH(cs, ccs) {
151         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
152         cpu_ppc_store_hdecr(cenv, val);
153     }
154 }
155 
156 void helper_store_vtb(CPUPPCState *env, target_ulong val)
157 {
158     CPUState *cs = env_cpu(env);
159     CPUState *ccs;
160     uint32_t nr_threads = cs->nr_threads;
161 
162     if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
163         cpu_ppc_store_vtb(env, val);
164         return;
165     }
166 
167     THREAD_SIBLING_FOREACH(cs, ccs) {
168         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
169         cpu_ppc_store_vtb(cenv, val);
170     }
171 }
172 
173 void helper_store_tbu40(CPUPPCState *env, target_ulong val)
174 {
175     CPUState *cs = env_cpu(env);
176     CPUState *ccs;
177     uint32_t nr_threads = cs->nr_threads;
178 
179     if (nr_threads == 1 || !(env->flags & POWERPC_FLAG_SMT_1LPAR)) {
180         cpu_ppc_store_tbu40(env, val);
181         return;
182     }
183 
184     THREAD_SIBLING_FOREACH(cs, ccs) {
185         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
186         cpu_ppc_store_tbu40(cenv, val);
187     }
188 }
189 
190 target_ulong helper_load_40x_pit(CPUPPCState *env)
191 {
192     return load_40x_pit(env);
193 }
194 
195 void helper_store_40x_pit(CPUPPCState *env, target_ulong val)
196 {
197     store_40x_pit(env, val);
198 }
199 
200 void helper_store_40x_tcr(CPUPPCState *env, target_ulong val)
201 {
202     store_40x_tcr(env, val);
203 }
204 
205 void helper_store_40x_tsr(CPUPPCState *env, target_ulong val)
206 {
207     store_40x_tsr(env, val);
208 }
209 
210 void helper_store_booke_tcr(CPUPPCState *env, target_ulong val)
211 {
212     store_booke_tcr(env, val);
213 }
214 
215 void helper_store_booke_tsr(CPUPPCState *env, target_ulong val)
216 {
217     store_booke_tsr(env, val);
218 }
219 
220 #if defined(TARGET_PPC64)
221 /*
222  * POWER processor Timebase Facility
223  */
224 
225 /*
226  * The TBST is the timebase state machine, which is a per-core machine that
227  * is used to synchronize the core TB with the ChipTOD. States 3,4,5 are
228  * not used in POWER8/9/10.
229  *
230  * The state machine gets driven by writes to TFMR SPR from the core, and
231  * by signals from the ChipTOD. The state machine table for common
232  * transitions is as follows (according to hardware specs, not necessarily
233  * this implementation):
234  *
235  * | Cur            | Event                            | New |
236  * +----------------+----------------------------------+-----+
237  * | 0 RESET        | TFMR |= LOAD_TOD_MOD             | 1   |
238  * | 1 SEND_TOD_MOD | "immediate transition"           | 2   |
239  * | 2 NOT_SET      | mttbu/mttbu40/mttbl              | 2   |
240  * | 2 NOT_SET      | TFMR |= MOVE_CHIP_TOD_TO_TB      | 6   |
241  * | 6 SYNC_WAIT    | "sync pulse from ChipTOD"        | 7   |
242  * | 7 GET_TOD      | ChipTOD xscom MOVE_TOD_TO_TB_REG | 8   |
243  * | 8 TB_RUNNING   | mttbu/mttbu40                    | 8   |
244  * | 8 TB_RUNNING   | TFMR |= LOAD_TOD_MOD             | 1   |
245  * | 8 TB_RUNNING   | mttbl                            | 9   |
246  * | 9 TB_ERROR     | TFMR |= CLEAR_TB_ERRORS          | 0   |
247  *
248  * - LOAD_TOD_MOD will also move states 2,6 to state 1, omitted from table
249  *   because it's not a typical init flow.
250  *
251  * - The ERROR state can be entered from most/all other states on invalid
252  *   states (e.g., if some TFMR control bit is set from a state where it's
253  *   not listed to cause a transition away from), omitted to avoid clutter.
254  *
255  * Note: mttbl causes a timebase error because this inevitably causes
256  * ticks to be lost and TB to become unsynchronized, whereas TB can be
257  * adjusted using mttbu* without losing ticks. mttbl behaviour is not
258  * modelled.
259  *
260  * Note: the TB state machine does not actually cause any real TB adjustment!
261  * TB starts out synchronized across all vCPUs (hardware threads) in
262  * QMEU, so for now the purpose of the TBST and ChipTOD model is simply
263  * to step through firmware initialisation sequences.
264  */
265 static unsigned int tfmr_get_tb_state(uint64_t tfmr)
266 {
267     return (tfmr & TFMR_TBST_ENCODED) >> (63 - 31);
268 }
269 
270 static uint64_t tfmr_new_tb_state(uint64_t tfmr, unsigned int tbst)
271 {
272     tfmr &= ~TFMR_TBST_LAST;
273     tfmr |= (tfmr & TFMR_TBST_ENCODED) >> 4; /* move state to last state */
274     tfmr &= ~TFMR_TBST_ENCODED;
275     tfmr |= (uint64_t)tbst << (63 - 31); /* move new state to state */
276 
277     if (tbst == TBST_TB_RUNNING) {
278         tfmr |= TFMR_TB_VALID;
279     } else {
280         tfmr &= ~TFMR_TB_VALID;
281     }
282 
283     return tfmr;
284 }
285 
286 static void write_tfmr(CPUPPCState *env, target_ulong val)
287 {
288     CPUState *cs = env_cpu(env);
289 
290     if (cs->nr_threads == 1) {
291         env->spr[SPR_TFMR] = val;
292     } else {
293         CPUState *ccs;
294         THREAD_SIBLING_FOREACH(cs, ccs) {
295             CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
296             cenv->spr[SPR_TFMR] = val;
297         }
298     }
299 }
300 
301 static void tb_state_machine_step(CPUPPCState *env)
302 {
303     uint64_t tfmr = env->spr[SPR_TFMR];
304     unsigned int tbst = tfmr_get_tb_state(tfmr);
305 
306     if (!(tfmr & TFMR_TB_ECLIPZ) || tbst == TBST_TB_ERROR) {
307         return;
308     }
309 
310     if (env->pnv_tod_tbst.tb_sync_pulse_timer) {
311         env->pnv_tod_tbst.tb_sync_pulse_timer--;
312     } else {
313         tfmr |= TFMR_TB_SYNC_OCCURED;
314         write_tfmr(env, tfmr);
315     }
316 
317     if (env->pnv_tod_tbst.tb_state_timer) {
318         env->pnv_tod_tbst.tb_state_timer--;
319         return;
320     }
321 
322     if (tfmr & TFMR_LOAD_TOD_MOD) {
323         tfmr &= ~TFMR_LOAD_TOD_MOD;
324         if (tbst == TBST_GET_TOD) {
325             tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
326             tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
327         } else {
328             tfmr = tfmr_new_tb_state(tfmr, TBST_SEND_TOD_MOD);
329             /* State seems to transition immediately */
330             tfmr = tfmr_new_tb_state(tfmr, TBST_NOT_SET);
331         }
332     } else if (tfmr & TFMR_MOVE_CHIP_TOD_TO_TB) {
333         if (tbst == TBST_SYNC_WAIT) {
334             tfmr = tfmr_new_tb_state(tfmr, TBST_GET_TOD);
335             env->pnv_tod_tbst.tb_state_timer = 3;
336         } else if (tbst == TBST_GET_TOD) {
337             if (env->pnv_tod_tbst.tod_sent_to_tb) {
338                 tfmr = tfmr_new_tb_state(tfmr, TBST_TB_RUNNING);
339                 tfmr &= ~TFMR_MOVE_CHIP_TOD_TO_TB;
340                 env->pnv_tod_tbst.tb_ready_for_tod = 0;
341                 env->pnv_tod_tbst.tod_sent_to_tb = 0;
342             }
343         } else {
344             qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: MOVE_CHIP_TOD_TO_TB "
345                           "state machine in invalid state 0x%x\n", tbst);
346             tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
347             tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
348             env->pnv_tod_tbst.tb_ready_for_tod = 0;
349         }
350     }
351 
352     write_tfmr(env, tfmr);
353 }
354 
355 target_ulong helper_load_tfmr(CPUPPCState *env)
356 {
357     tb_state_machine_step(env);
358 
359     return env->spr[SPR_TFMR] | TFMR_TB_ECLIPZ;
360 }
361 
362 void helper_store_tfmr(CPUPPCState *env, target_ulong val)
363 {
364     uint64_t tfmr = env->spr[SPR_TFMR];
365     uint64_t clear_on_write;
366     unsigned int tbst = tfmr_get_tb_state(tfmr);
367 
368     if (!(val & TFMR_TB_ECLIPZ)) {
369         qemu_log_mask(LOG_UNIMP, "TFMR non-ECLIPZ mode not implemented\n");
370         tfmr &= ~TFMR_TBST_ENCODED;
371         tfmr &= ~TFMR_TBST_LAST;
372         goto out;
373     }
374 
375     /* Update control bits */
376     tfmr = (tfmr & ~TFMR_CONTROL_MASK) | (val & TFMR_CONTROL_MASK);
377 
378     /* Several bits are clear-on-write, only one is implemented so far */
379     clear_on_write = val & TFMR_FIRMWARE_CONTROL_ERROR;
380     tfmr &= ~clear_on_write;
381 
382     /*
383      * mtspr always clears this. The sync pulse timer makes it come back
384      * after the second mfspr.
385      */
386     tfmr &= ~TFMR_TB_SYNC_OCCURED;
387     env->pnv_tod_tbst.tb_sync_pulse_timer = 1;
388 
389     if (ppc_cpu_tir(env_archcpu(env)) != 0 &&
390         (val & (TFMR_LOAD_TOD_MOD | TFMR_MOVE_CHIP_TOD_TO_TB))) {
391         qemu_log_mask(LOG_UNIMP, "TFMR timebase state machine can only be "
392                                  "driven by thread 0\n");
393         goto out;
394     }
395 
396     if (((tfmr | val) & (TFMR_LOAD_TOD_MOD | TFMR_MOVE_CHIP_TOD_TO_TB)) ==
397                         (TFMR_LOAD_TOD_MOD | TFMR_MOVE_CHIP_TOD_TO_TB)) {
398         qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: LOAD_TOD_MOD and "
399                                        "MOVE_CHIP_TOD_TO_TB both set\n");
400         tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
401         tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
402         env->pnv_tod_tbst.tb_ready_for_tod = 0;
403         goto out;
404     }
405 
406     if (tfmr & TFMR_CLEAR_TB_ERRORS) {
407         /*
408          * Workbook says TFMR_CLEAR_TB_ERRORS should be written twice.
409          * This is not simulated/required here.
410          */
411         tfmr = tfmr_new_tb_state(tfmr, TBST_RESET);
412         tfmr &= ~TFMR_CLEAR_TB_ERRORS;
413         tfmr &= ~TFMR_LOAD_TOD_MOD;
414         tfmr &= ~TFMR_MOVE_CHIP_TOD_TO_TB;
415         tfmr &= ~TFMR_FIRMWARE_CONTROL_ERROR; /* XXX: should this be cleared? */
416         env->pnv_tod_tbst.tb_ready_for_tod = 0;
417         env->pnv_tod_tbst.tod_sent_to_tb = 0;
418         goto out;
419     }
420 
421     if (tbst == TBST_TB_ERROR) {
422         qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: mtspr TFMR in TB_ERROR"
423                                        " state\n");
424         tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
425         return;
426     }
427 
428     if (tfmr & TFMR_LOAD_TOD_MOD) {
429         /* Wait for an arbitrary 3 mfspr until the next state transition. */
430         env->pnv_tod_tbst.tb_state_timer = 3;
431     } else if (tfmr & TFMR_MOVE_CHIP_TOD_TO_TB) {
432         if (tbst == TBST_NOT_SET) {
433             tfmr = tfmr_new_tb_state(tfmr, TBST_SYNC_WAIT);
434             env->pnv_tod_tbst.tb_ready_for_tod = 1;
435             env->pnv_tod_tbst.tb_state_timer = 3; /* arbitrary */
436         } else {
437             qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: MOVE_CHIP_TOD_TO_TB "
438                                            "not in TB not set state 0x%x\n",
439                                            tbst);
440             tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
441             tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
442             env->pnv_tod_tbst.tb_ready_for_tod = 0;
443         }
444     }
445 
446 out:
447     write_tfmr(env, tfmr);
448 }
449 #endif
450 
451 /*****************************************************************************/
452 /* Embedded PowerPC specific helpers */
453 
454 /* XXX: to be improved to check access rights when in user-mode */
455 target_ulong helper_load_dcr(CPUPPCState *env, target_ulong dcrn)
456 {
457     uint32_t val = 0;
458 
459     if (unlikely(env->dcr_env == NULL)) {
460         qemu_log_mask(LOG_GUEST_ERROR, "No DCR environment\n");
461         raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
462                                POWERPC_EXCP_INVAL |
463                                POWERPC_EXCP_INVAL_INVAL, GETPC());
464     } else {
465         int ret;
466 
467         bql_lock();
468         ret = ppc_dcr_read(env->dcr_env, (uint32_t)dcrn, &val);
469         bql_unlock();
470         if (unlikely(ret != 0)) {
471             qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n",
472                           (uint32_t)dcrn, (uint32_t)dcrn);
473             raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
474                                    POWERPC_EXCP_INVAL |
475                                    POWERPC_EXCP_INVAL_INVAL, GETPC());
476         }
477     }
478     return val;
479 }
480 
481 void helper_store_dcr(CPUPPCState *env, target_ulong dcrn, target_ulong val)
482 {
483     if (unlikely(env->dcr_env == NULL)) {
484         qemu_log_mask(LOG_GUEST_ERROR, "No DCR environment\n");
485         raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
486                                POWERPC_EXCP_INVAL |
487                                POWERPC_EXCP_INVAL_INVAL, GETPC());
488     } else {
489         int ret;
490         bql_lock();
491         ret = ppc_dcr_write(env->dcr_env, (uint32_t)dcrn, (uint32_t)val);
492         bql_unlock();
493         if (unlikely(ret != 0)) {
494             qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n",
495                           (uint32_t)dcrn, (uint32_t)dcrn);
496             raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
497                                    POWERPC_EXCP_INVAL |
498                                    POWERPC_EXCP_INVAL_INVAL, GETPC());
499         }
500     }
501 }
502 #endif
503