xref: /openbmc/qemu/target/ppc/timebase_helper.c (revision 59c921f2297d6e293fde593432acf90d819e4d51)
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 
66     if (ppc_cpu_lpar_single_threaded(cs)) {
67         cpu_ppc_store_purr(env, val);
68         return;
69     }
70 
71     THREAD_SIBLING_FOREACH(cs, ccs) {
72         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
73         cpu_ppc_store_purr(cenv, val);
74     }
75 }
76 #endif
77 
78 #if !defined(CONFIG_USER_ONLY)
79 void helper_store_tbl(CPUPPCState *env, target_ulong val)
80 {
81     CPUState *cs = env_cpu(env);
82     CPUState *ccs;
83 
84     if (ppc_cpu_lpar_single_threaded(cs)) {
85         cpu_ppc_store_tbl(env, val);
86         return;
87     }
88 
89     THREAD_SIBLING_FOREACH(cs, ccs) {
90         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
91         cpu_ppc_store_tbl(cenv, val);
92     }
93 }
94 
95 void helper_store_tbu(CPUPPCState *env, target_ulong val)
96 {
97     CPUState *cs = env_cpu(env);
98     CPUState *ccs;
99 
100     if (ppc_cpu_lpar_single_threaded(cs)) {
101         cpu_ppc_store_tbu(env, val);
102         return;
103     }
104 
105     THREAD_SIBLING_FOREACH(cs, ccs) {
106         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
107         cpu_ppc_store_tbu(cenv, val);
108     }
109 }
110 
111 void helper_store_atbl(CPUPPCState *env, target_ulong val)
112 {
113     cpu_ppc_store_atbl(env, val);
114 }
115 
116 void helper_store_atbu(CPUPPCState *env, target_ulong val)
117 {
118     cpu_ppc_store_atbu(env, val);
119 }
120 
121 target_ulong helper_load_decr(CPUPPCState *env)
122 {
123     return cpu_ppc_load_decr(env);
124 }
125 
126 void helper_store_decr(CPUPPCState *env, target_ulong val)
127 {
128     cpu_ppc_store_decr(env, val);
129 }
130 
131 target_ulong helper_load_hdecr(CPUPPCState *env)
132 {
133     return cpu_ppc_load_hdecr(env);
134 }
135 
136 void helper_store_hdecr(CPUPPCState *env, target_ulong val)
137 {
138     CPUState *cs = env_cpu(env);
139     CPUState *ccs;
140 
141     if (ppc_cpu_lpar_single_threaded(cs)) {
142         cpu_ppc_store_hdecr(env, val);
143         return;
144     }
145 
146     THREAD_SIBLING_FOREACH(cs, ccs) {
147         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
148         cpu_ppc_store_hdecr(cenv, val);
149     }
150 }
151 
152 void helper_store_vtb(CPUPPCState *env, target_ulong val)
153 {
154     CPUState *cs = env_cpu(env);
155     CPUState *ccs;
156 
157     if (ppc_cpu_lpar_single_threaded(cs)) {
158         cpu_ppc_store_vtb(env, val);
159         return;
160     }
161 
162     THREAD_SIBLING_FOREACH(cs, ccs) {
163         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
164         cpu_ppc_store_vtb(cenv, val);
165     }
166 }
167 
168 void helper_store_tbu40(CPUPPCState *env, target_ulong val)
169 {
170     CPUState *cs = env_cpu(env);
171     CPUState *ccs;
172 
173     if (ppc_cpu_lpar_single_threaded(cs)) {
174         cpu_ppc_store_tbu40(env, val);
175         return;
176     }
177 
178     THREAD_SIBLING_FOREACH(cs, ccs) {
179         CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
180         cpu_ppc_store_tbu40(cenv, val);
181     }
182 }
183 
184 target_ulong helper_load_40x_pit(CPUPPCState *env)
185 {
186     return load_40x_pit(env);
187 }
188 
189 void helper_store_40x_pit(CPUPPCState *env, target_ulong val)
190 {
191     store_40x_pit(env, val);
192 }
193 
194 void helper_store_40x_tcr(CPUPPCState *env, target_ulong val)
195 {
196     store_40x_tcr(env, val);
197 }
198 
199 void helper_store_40x_tsr(CPUPPCState *env, target_ulong val)
200 {
201     store_40x_tsr(env, val);
202 }
203 
204 void helper_store_booke_tcr(CPUPPCState *env, target_ulong val)
205 {
206     store_booke_tcr(env, val);
207 }
208 
209 void helper_store_booke_tsr(CPUPPCState *env, target_ulong val)
210 {
211     store_booke_tsr(env, val);
212 }
213 
214 #if defined(TARGET_PPC64) && !defined(CONFIG_USER_ONLY)
215 /*
216  * qemu-user breaks with pnv headers, so they go under ifdefs for now.
217  * A clean up may be to move powernv specific registers and helpers into
218  * target/ppc/pnv_helper.c
219  */
220 #include "hw/ppc/pnv_core.h"
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 (ppc_cpu_core_single_threaded(cs)) {
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 PnvCoreTODState *cpu_get_tbst(PowerPCCPU *cpu)
302 {
303     PnvCore *pc = pnv_cpu_state(cpu)->pnv_core;
304 
305     return &pc->tod_state;
306 }
307 
308 static void tb_state_machine_step(CPUPPCState *env)
309 {
310     PowerPCCPU *cpu = env_archcpu(env);
311     PnvCoreTODState *tod_state = cpu_get_tbst(cpu);
312     uint64_t tfmr = env->spr[SPR_TFMR];
313     unsigned int tbst = tfmr_get_tb_state(tfmr);
314 
315     if (!(tfmr & TFMR_TB_ECLIPZ) || tbst == TBST_TB_ERROR) {
316         return;
317     }
318 
319     if (tod_state->tb_sync_pulse_timer) {
320         tod_state->tb_sync_pulse_timer--;
321     } else {
322         tfmr |= TFMR_TB_SYNC_OCCURED;
323         write_tfmr(env, tfmr);
324     }
325 
326     if (tod_state->tb_state_timer) {
327         tod_state->tb_state_timer--;
328         return;
329     }
330 
331     if (tfmr & TFMR_LOAD_TOD_MOD) {
332         tfmr &= ~TFMR_LOAD_TOD_MOD;
333         if (tbst == TBST_GET_TOD) {
334             tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
335             tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
336         } else {
337             tfmr = tfmr_new_tb_state(tfmr, TBST_SEND_TOD_MOD);
338             /* State seems to transition immediately */
339             tfmr = tfmr_new_tb_state(tfmr, TBST_NOT_SET);
340         }
341     } else if (tfmr & TFMR_MOVE_CHIP_TOD_TO_TB) {
342         if (tbst == TBST_SYNC_WAIT) {
343             tfmr = tfmr_new_tb_state(tfmr, TBST_GET_TOD);
344             tod_state->tb_state_timer = 3;
345         } else if (tbst == TBST_GET_TOD) {
346             if (tod_state->tod_sent_to_tb) {
347                 tfmr = tfmr_new_tb_state(tfmr, TBST_TB_RUNNING);
348                 tfmr &= ~TFMR_MOVE_CHIP_TOD_TO_TB;
349                 tod_state->tb_ready_for_tod = 0;
350                 tod_state->tod_sent_to_tb = 0;
351             }
352         } else {
353             qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: MOVE_CHIP_TOD_TO_TB "
354                           "state machine in invalid state 0x%x\n", tbst);
355             tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
356             tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
357             tod_state->tb_ready_for_tod = 0;
358         }
359     }
360 
361     write_tfmr(env, tfmr);
362 }
363 
364 target_ulong helper_load_tfmr(CPUPPCState *env)
365 {
366     tb_state_machine_step(env);
367 
368     return env->spr[SPR_TFMR] | TFMR_TB_ECLIPZ;
369 }
370 
371 void helper_store_tfmr(CPUPPCState *env, target_ulong val)
372 {
373     PowerPCCPU *cpu = env_archcpu(env);
374     PnvCoreTODState *tod_state = cpu_get_tbst(cpu);
375     uint64_t tfmr = env->spr[SPR_TFMR];
376     uint64_t clear_on_write;
377     unsigned int tbst = tfmr_get_tb_state(tfmr);
378 
379     if (!(val & TFMR_TB_ECLIPZ)) {
380         qemu_log_mask(LOG_UNIMP, "TFMR non-ECLIPZ mode not implemented\n");
381         tfmr &= ~TFMR_TBST_ENCODED;
382         tfmr &= ~TFMR_TBST_LAST;
383         goto out;
384     }
385 
386     /* Update control bits */
387     tfmr = (tfmr & ~TFMR_CONTROL_MASK) | (val & TFMR_CONTROL_MASK);
388 
389     /* Several bits are clear-on-write, only one is implemented so far */
390     clear_on_write = val & TFMR_FIRMWARE_CONTROL_ERROR;
391     tfmr &= ~clear_on_write;
392 
393     /*
394      * mtspr always clears this. The sync pulse timer makes it come back
395      * after the second mfspr.
396      */
397     tfmr &= ~TFMR_TB_SYNC_OCCURED;
398     tod_state->tb_sync_pulse_timer = 1;
399 
400     if (((tfmr | val) & (TFMR_LOAD_TOD_MOD | TFMR_MOVE_CHIP_TOD_TO_TB)) ==
401                         (TFMR_LOAD_TOD_MOD | TFMR_MOVE_CHIP_TOD_TO_TB)) {
402         qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: LOAD_TOD_MOD and "
403                                        "MOVE_CHIP_TOD_TO_TB both set\n");
404         tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
405         tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
406         tod_state->tb_ready_for_tod = 0;
407         goto out;
408     }
409 
410     if (tfmr & TFMR_CLEAR_TB_ERRORS) {
411         /*
412          * Workbook says TFMR_CLEAR_TB_ERRORS should be written twice.
413          * This is not simulated/required here.
414          */
415         tfmr = tfmr_new_tb_state(tfmr, TBST_RESET);
416         tfmr &= ~TFMR_CLEAR_TB_ERRORS;
417         tfmr &= ~TFMR_LOAD_TOD_MOD;
418         tfmr &= ~TFMR_MOVE_CHIP_TOD_TO_TB;
419         tfmr &= ~TFMR_FIRMWARE_CONTROL_ERROR; /* XXX: should this be cleared? */
420         tod_state->tb_ready_for_tod = 0;
421         tod_state->tod_sent_to_tb = 0;
422         goto out;
423     }
424 
425     if (tbst == TBST_TB_ERROR) {
426         qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: mtspr TFMR in TB_ERROR"
427                                        " state\n");
428         tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
429         return;
430     }
431 
432     if (tfmr & TFMR_LOAD_TOD_MOD) {
433         /* Wait for an arbitrary 3 mfspr until the next state transition. */
434         tod_state->tb_state_timer = 3;
435     } else if (tfmr & TFMR_MOVE_CHIP_TOD_TO_TB) {
436         if (tbst == TBST_NOT_SET) {
437             tfmr = tfmr_new_tb_state(tfmr, TBST_SYNC_WAIT);
438             tod_state->tb_ready_for_tod = 1;
439             tod_state->tb_state_timer = 3; /* arbitrary */
440         } else {
441             qemu_log_mask(LOG_GUEST_ERROR, "TFMR error: MOVE_CHIP_TOD_TO_TB "
442                                            "not in TB not set state 0x%x\n",
443                                            tbst);
444             tfmr = tfmr_new_tb_state(tfmr, TBST_TB_ERROR);
445             tfmr |= TFMR_FIRMWARE_CONTROL_ERROR;
446             tod_state->tb_ready_for_tod = 0;
447         }
448     }
449 
450 out:
451     write_tfmr(env, tfmr);
452 }
453 #endif
454 
455 /*****************************************************************************/
456 /* Embedded PowerPC specific helpers */
457 
458 /* XXX: to be improved to check access rights when in user-mode */
459 target_ulong helper_load_dcr(CPUPPCState *env, target_ulong dcrn)
460 {
461     uint32_t val = 0;
462 
463     if (unlikely(env->dcr_env == NULL)) {
464         qemu_log_mask(LOG_GUEST_ERROR, "No DCR environment\n");
465         raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
466                                POWERPC_EXCP_INVAL |
467                                POWERPC_EXCP_INVAL_INVAL, GETPC());
468     } else {
469         int ret;
470 
471         bql_lock();
472         ret = ppc_dcr_read(env->dcr_env, (uint32_t)dcrn, &val);
473         bql_unlock();
474         if (unlikely(ret != 0)) {
475             qemu_log_mask(LOG_GUEST_ERROR, "DCR read error %d %03x\n",
476                           (uint32_t)dcrn, (uint32_t)dcrn);
477             raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
478                                    POWERPC_EXCP_INVAL |
479                                    POWERPC_EXCP_INVAL_INVAL, GETPC());
480         }
481     }
482     return val;
483 }
484 
485 void helper_store_dcr(CPUPPCState *env, target_ulong dcrn, target_ulong val)
486 {
487     if (unlikely(env->dcr_env == NULL)) {
488         qemu_log_mask(LOG_GUEST_ERROR, "No DCR environment\n");
489         raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
490                                POWERPC_EXCP_INVAL |
491                                POWERPC_EXCP_INVAL_INVAL, GETPC());
492     } else {
493         int ret;
494         bql_lock();
495         ret = ppc_dcr_write(env->dcr_env, (uint32_t)dcrn, (uint32_t)val);
496         bql_unlock();
497         if (unlikely(ret != 0)) {
498             qemu_log_mask(LOG_GUEST_ERROR, "DCR write error %d %03x\n",
499                           (uint32_t)dcrn, (uint32_t)dcrn);
500             raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
501                                    POWERPC_EXCP_INVAL |
502                                    POWERPC_EXCP_INVAL_INVAL, GETPC());
503         }
504     }
505 }
506 #endif
507