xref: /openbmc/qemu/hw/ppc/ppc_booke.c (revision e50a24ea)
1 /*
2  * QEMU PowerPC Booke hardware System Emulator
3  *
4  * Copyright (c) 2011 AdaCore
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "cpu.h"
27 #include "hw/ppc/ppc.h"
28 #include "qemu/timer.h"
29 #include "sysemu/reset.h"
30 #include "sysemu/runstate.h"
31 #include "hw/loader.h"
32 #include "kvm_ppc.h"
33 
34 void booke_set_tlb(ppcemb_tlb_t *tlb, target_ulong va, hwaddr pa,
35                    target_ulong size)
36 {
37     tlb->attr = 0;
38     tlb->prot = PAGE_RWX << 4 | PAGE_VALID;
39     tlb->size = size;
40     tlb->EPN = va & TARGET_PAGE_MASK;
41     tlb->RPN = pa & TARGET_PAGE_MASK;
42     tlb->PID = 0;
43 }
44 
45 /* Timer Control Register */
46 
47 #define TCR_WP_SHIFT  30        /* Watchdog Timer Period */
48 #define TCR_WP_MASK   (0x3U << TCR_WP_SHIFT)
49 #define TCR_WRC_SHIFT 28        /* Watchdog Timer Reset Control */
50 #define TCR_WRC_MASK  (0x3U << TCR_WRC_SHIFT)
51 #define TCR_WIE       (1U << 27) /* Watchdog Timer Interrupt Enable */
52 #define TCR_DIE       (1U << 26) /* Decrementer Interrupt Enable */
53 #define TCR_FP_SHIFT  24        /* Fixed-Interval Timer Period */
54 #define TCR_FP_MASK   (0x3U << TCR_FP_SHIFT)
55 #define TCR_FIE       (1U << 23) /* Fixed-Interval Timer Interrupt Enable */
56 #define TCR_ARE       (1U << 22) /* Auto-Reload Enable */
57 
58 /* Timer Control Register (e500 specific fields) */
59 
60 #define TCR_E500_FPEXT_SHIFT 13 /* Fixed-Interval Timer Period Extension */
61 #define TCR_E500_FPEXT_MASK  (0xf << TCR_E500_FPEXT_SHIFT)
62 #define TCR_E500_WPEXT_SHIFT 17 /* Watchdog Timer Period Extension */
63 #define TCR_E500_WPEXT_MASK  (0xf << TCR_E500_WPEXT_SHIFT)
64 
65 /* Timer Status Register  */
66 
67 #define TSR_FIS       (1U << 26) /* Fixed-Interval Timer Interrupt Status */
68 #define TSR_DIS       (1U << 27) /* Decrementer Interrupt Status */
69 #define TSR_WRS_SHIFT 28        /* Watchdog Timer Reset Status */
70 #define TSR_WRS_MASK  (0x3U << TSR_WRS_SHIFT)
71 #define TSR_WIS       (1U << 30) /* Watchdog Timer Interrupt Status */
72 #define TSR_ENW       (1U << 31) /* Enable Next Watchdog Timer */
73 
74 typedef struct booke_timer_t booke_timer_t;
75 struct booke_timer_t {
76 
77     uint64_t fit_next;
78     QEMUTimer *fit_timer;
79 
80     uint64_t wdt_next;
81     QEMUTimer *wdt_timer;
82 
83     uint32_t flags;
84 };
85 
86 static void booke_update_irq(PowerPCCPU *cpu)
87 {
88     CPUPPCState *env = &cpu->env;
89 
90     ppc_set_irq(cpu, PPC_INTERRUPT_DECR,
91                 (env->spr[SPR_BOOKE_TSR] & TSR_DIS
92                  && env->spr[SPR_BOOKE_TCR] & TCR_DIE));
93 
94     ppc_set_irq(cpu, PPC_INTERRUPT_WDT,
95                 (env->spr[SPR_BOOKE_TSR] & TSR_WIS
96                  && env->spr[SPR_BOOKE_TCR] & TCR_WIE));
97 
98     ppc_set_irq(cpu, PPC_INTERRUPT_FIT,
99                 (env->spr[SPR_BOOKE_TSR] & TSR_FIS
100                  && env->spr[SPR_BOOKE_TCR] & TCR_FIE));
101 }
102 
103 /* Return the location of the bit of time base at which the FIT will raise an
104    interrupt */
105 static uint8_t booke_get_fit_target(CPUPPCState *env, ppc_tb_t *tb_env)
106 {
107     uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;
108 
109     if (tb_env->flags & PPC_TIMER_E500) {
110         /* e500 Fixed-interval timer period extension */
111         uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
112             >> TCR_E500_FPEXT_SHIFT;
113         fp = 63 - (fp | fpext << 2);
114     } else {
115         fp = env->fit_period[fp];
116     }
117 
118     return fp;
119 }
120 
121 /* Return the location of the bit of time base at which the WDT will raise an
122    interrupt */
123 static uint8_t booke_get_wdt_target(CPUPPCState *env, ppc_tb_t *tb_env)
124 {
125     uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;
126 
127     if (tb_env->flags & PPC_TIMER_E500) {
128         /* e500 Watchdog timer period extension */
129         uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
130             >> TCR_E500_WPEXT_SHIFT;
131         wp = 63 - (wp | wpext << 2);
132     } else {
133         wp = env->wdt_period[wp];
134     }
135 
136     return wp;
137 }
138 
139 static void booke_update_fixed_timer(CPUPPCState         *env,
140                                      uint8_t           target_bit,
141                                      uint64_t          *next,
142                                      QEMUTimer         *timer,
143                                      int               tsr_bit)
144 {
145     ppc_tb_t *tb_env = env->tb_env;
146     uint64_t delta_tick, ticks = 0;
147     uint64_t tb;
148     uint64_t period;
149     uint64_t now;
150 
151     if (!(env->spr[SPR_BOOKE_TSR] & tsr_bit)) {
152         /*
153          * Don't arm the timer again when the guest has the current
154          * interrupt still pending. Wait for it to ack it.
155          */
156         return;
157     }
158 
159     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
160     tb  = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
161     period = 1ULL << target_bit;
162     delta_tick = period - (tb & (period - 1));
163 
164     /* the timer triggers only when the selected bit toggles from 0 to 1 */
165     if (tb & period) {
166         ticks = period;
167     }
168 
169     if (ticks + delta_tick < ticks) {
170         /* Overflow, so assume the biggest number we can express. */
171         ticks = UINT64_MAX;
172     } else {
173         ticks += delta_tick;
174     }
175 
176     *next = now + muldiv64(ticks, NANOSECONDS_PER_SECOND, tb_env->tb_freq);
177     if ((*next < now) || (*next > INT64_MAX)) {
178         /* Overflow, so assume the biggest number the qemu timer supports. */
179         *next = INT64_MAX;
180     }
181 
182     /* XXX: If expire time is now. We can't run the callback because we don't
183      * have access to it. So we just set the timer one nanosecond later.
184      */
185 
186     if (*next == now) {
187         (*next)++;
188     } else {
189         /*
190          * There's no point to fake any granularity that's more fine grained
191          * than milliseconds. Anything beyond that just overloads the system.
192          */
193         *next = MAX(*next, now + SCALE_MS);
194     }
195 
196     /* Fire the next timer */
197     timer_mod(timer, *next);
198 }
199 
200 static void booke_decr_cb(void *opaque)
201 {
202     PowerPCCPU *cpu = opaque;
203     CPUPPCState *env = &cpu->env;
204 
205     env->spr[SPR_BOOKE_TSR] |= TSR_DIS;
206     booke_update_irq(cpu);
207 
208     if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
209         /* Do not reload 0, it is already there. It would just trigger
210          * the timer again and lead to infinite loop */
211         if (env->spr[SPR_BOOKE_DECAR] != 0) {
212             /* Auto Reload */
213             cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
214         }
215     }
216 }
217 
218 static void booke_fit_cb(void *opaque)
219 {
220     PowerPCCPU *cpu = opaque;
221     CPUPPCState *env = &cpu->env;
222     ppc_tb_t *tb_env;
223     booke_timer_t *booke_timer;
224 
225     tb_env = env->tb_env;
226     booke_timer = tb_env->opaque;
227     env->spr[SPR_BOOKE_TSR] |= TSR_FIS;
228 
229     booke_update_irq(cpu);
230 
231     booke_update_fixed_timer(env,
232                              booke_get_fit_target(env, tb_env),
233                              &booke_timer->fit_next,
234                              booke_timer->fit_timer,
235                              TSR_FIS);
236 }
237 
238 static void booke_wdt_cb(void *opaque)
239 {
240     PowerPCCPU *cpu = opaque;
241     CPUPPCState *env = &cpu->env;
242     ppc_tb_t *tb_env;
243     booke_timer_t *booke_timer;
244 
245     tb_env = env->tb_env;
246     booke_timer = tb_env->opaque;
247 
248     /* TODO: There's lots of complicated stuff to do here */
249 
250     booke_update_irq(cpu);
251 
252     booke_update_fixed_timer(env,
253                              booke_get_wdt_target(env, tb_env),
254                              &booke_timer->wdt_next,
255                              booke_timer->wdt_timer,
256                              TSR_WIS);
257 }
258 
259 void store_booke_tsr(CPUPPCState *env, target_ulong val)
260 {
261     PowerPCCPU *cpu = env_archcpu(env);
262     ppc_tb_t *tb_env = env->tb_env;
263     booke_timer_t *booke_timer = tb_env->opaque;
264 
265     env->spr[SPR_BOOKE_TSR] &= ~val;
266     kvmppc_clear_tsr_bits(cpu, val);
267 
268     if (val & TSR_FIS) {
269         booke_update_fixed_timer(env,
270                                  booke_get_fit_target(env, tb_env),
271                                  &booke_timer->fit_next,
272                                  booke_timer->fit_timer,
273                                  TSR_FIS);
274     }
275 
276     if (val & TSR_WIS) {
277         booke_update_fixed_timer(env,
278                                  booke_get_wdt_target(env, tb_env),
279                                  &booke_timer->wdt_next,
280                                  booke_timer->wdt_timer,
281                                  TSR_WIS);
282     }
283 
284     booke_update_irq(cpu);
285 }
286 
287 void store_booke_tcr(CPUPPCState *env, target_ulong val)
288 {
289     PowerPCCPU *cpu = env_archcpu(env);
290     ppc_tb_t *tb_env = env->tb_env;
291     booke_timer_t *booke_timer = tb_env->opaque;
292 
293     env->spr[SPR_BOOKE_TCR] = val;
294     kvmppc_set_tcr(cpu);
295 
296     booke_update_irq(cpu);
297 
298     booke_update_fixed_timer(env,
299                              booke_get_fit_target(env, tb_env),
300                              &booke_timer->fit_next,
301                              booke_timer->fit_timer,
302                              TSR_FIS);
303 
304     booke_update_fixed_timer(env,
305                              booke_get_wdt_target(env, tb_env),
306                              &booke_timer->wdt_next,
307                              booke_timer->wdt_timer,
308                              TSR_WIS);
309 }
310 
311 static void ppc_booke_timer_reset_handle(void *opaque)
312 {
313     PowerPCCPU *cpu = opaque;
314     CPUPPCState *env = &cpu->env;
315 
316     store_booke_tcr(env, 0);
317     store_booke_tsr(env, -1);
318 }
319 
320 /*
321  * This function will be called whenever the CPU state changes.
322  * CPU states are defined "typedef enum RunState".
323  * Regarding timer, When CPU state changes to running after debug halt
324  * or similar cases which takes time then in between final watchdog
325  * expiry happenes. This will cause exit to QEMU and configured watchdog
326  * action will be taken. To avoid this we always clear the watchdog state when
327  * state changes to running.
328  */
329 static void cpu_state_change_handler(void *opaque, bool running, RunState state)
330 {
331     PowerPCCPU *cpu = opaque;
332     CPUPPCState *env = &cpu->env;
333 
334     if (!running) {
335         return;
336     }
337 
338     /*
339      * Clear watchdog interrupt condition by clearing TSR.
340      */
341     store_booke_tsr(env, TSR_ENW | TSR_WIS | TSR_WRS_MASK);
342 }
343 
344 void ppc_booke_timers_init(PowerPCCPU *cpu, uint32_t freq, uint32_t flags)
345 {
346     ppc_tb_t *tb_env;
347     booke_timer_t *booke_timer;
348     int ret = 0;
349 
350     tb_env      = g_new0(ppc_tb_t, 1);
351     booke_timer = g_new0(booke_timer_t, 1);
352 
353     cpu->env.tb_env = tb_env;
354     tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;
355 
356     tb_env->tb_freq    = freq;
357     tb_env->decr_freq  = freq;
358     tb_env->opaque     = booke_timer;
359     tb_env->decr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_decr_cb, cpu);
360 
361     booke_timer->fit_timer =
362         timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_fit_cb, cpu);
363     booke_timer->wdt_timer =
364         timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_wdt_cb, cpu);
365 
366     ret = kvmppc_booke_watchdog_enable(cpu);
367 
368     if (ret) {
369         /* TODO: Start the QEMU emulated watchdog if not running on KVM.
370          * Also start the QEMU emulated watchdog if KVM does not support
371          * emulated watchdog or somehow it is not enabled (supported but
372          * not enabled is though some bug and requires debugging :)).
373          */
374     }
375 
376     qemu_add_vm_change_state_handler(cpu_state_change_handler, cpu);
377 
378     qemu_register_reset(ppc_booke_timer_reset_handle, cpu);
379 }
380