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
35 /* Timer Control Register */
36
37 #define TCR_WP_SHIFT 30 /* Watchdog Timer Period */
38 #define TCR_WP_MASK (0x3U << TCR_WP_SHIFT)
39 #define TCR_WRC_SHIFT 28 /* Watchdog Timer Reset Control */
40 #define TCR_WRC_MASK (0x3U << TCR_WRC_SHIFT)
41 #define TCR_WIE (1U << 27) /* Watchdog Timer Interrupt Enable */
42 #define TCR_DIE (1U << 26) /* Decrementer Interrupt Enable */
43 #define TCR_FP_SHIFT 24 /* Fixed-Interval Timer Period */
44 #define TCR_FP_MASK (0x3U << TCR_FP_SHIFT)
45 #define TCR_FIE (1U << 23) /* Fixed-Interval Timer Interrupt Enable */
46 #define TCR_ARE (1U << 22) /* Auto-Reload Enable */
47
48 /* Timer Control Register (e500 specific fields) */
49
50 #define TCR_E500_FPEXT_SHIFT 13 /* Fixed-Interval Timer Period Extension */
51 #define TCR_E500_FPEXT_MASK (0xf << TCR_E500_FPEXT_SHIFT)
52 #define TCR_E500_WPEXT_SHIFT 17 /* Watchdog Timer Period Extension */
53 #define TCR_E500_WPEXT_MASK (0xf << TCR_E500_WPEXT_SHIFT)
54
55 /* Timer Status Register */
56
57 #define TSR_FIS (1U << 26) /* Fixed-Interval Timer Interrupt Status */
58 #define TSR_DIS (1U << 27) /* Decrementer Interrupt Status */
59 #define TSR_WRS_SHIFT 28 /* Watchdog Timer Reset Status */
60 #define TSR_WRS_MASK (0x3U << TSR_WRS_SHIFT)
61 #define TSR_WIS (1U << 30) /* Watchdog Timer Interrupt Status */
62 #define TSR_ENW (1U << 31) /* Enable Next Watchdog Timer */
63
64 typedef struct booke_timer_t booke_timer_t;
65 struct booke_timer_t {
66
67 uint64_t fit_next;
68 QEMUTimer *fit_timer;
69
70 uint64_t wdt_next;
71 QEMUTimer *wdt_timer;
72
73 uint32_t flags;
74 };
75
booke_update_irq(PowerPCCPU * cpu)76 static void booke_update_irq(PowerPCCPU *cpu)
77 {
78 CPUPPCState *env = &cpu->env;
79
80 ppc_set_irq(cpu, PPC_INTERRUPT_DECR,
81 (env->spr[SPR_BOOKE_TSR] & TSR_DIS
82 && env->spr[SPR_BOOKE_TCR] & TCR_DIE));
83
84 ppc_set_irq(cpu, PPC_INTERRUPT_WDT,
85 (env->spr[SPR_BOOKE_TSR] & TSR_WIS
86 && env->spr[SPR_BOOKE_TCR] & TCR_WIE));
87
88 ppc_set_irq(cpu, PPC_INTERRUPT_FIT,
89 (env->spr[SPR_BOOKE_TSR] & TSR_FIS
90 && env->spr[SPR_BOOKE_TCR] & TCR_FIE));
91 }
92
93 /* Return the location of the bit of time base at which the FIT will raise an
94 interrupt */
booke_get_fit_target(CPUPPCState * env,ppc_tb_t * tb_env)95 static uint8_t booke_get_fit_target(CPUPPCState *env, ppc_tb_t *tb_env)
96 {
97 uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;
98
99 if (tb_env->flags & PPC_TIMER_E500) {
100 /* e500 Fixed-interval timer period extension */
101 uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
102 >> TCR_E500_FPEXT_SHIFT;
103 fp = 63 - (fp | fpext << 2);
104 } else {
105 fp = env->fit_period[fp];
106 }
107
108 return fp;
109 }
110
111 /* Return the location of the bit of time base at which the WDT will raise an
112 interrupt */
booke_get_wdt_target(CPUPPCState * env,ppc_tb_t * tb_env)113 static uint8_t booke_get_wdt_target(CPUPPCState *env, ppc_tb_t *tb_env)
114 {
115 uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;
116
117 if (tb_env->flags & PPC_TIMER_E500) {
118 /* e500 Watchdog timer period extension */
119 uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
120 >> TCR_E500_WPEXT_SHIFT;
121 wp = 63 - (wp | wpext << 2);
122 } else {
123 wp = env->wdt_period[wp];
124 }
125
126 return wp;
127 }
128
booke_update_fixed_timer(CPUPPCState * env,uint8_t target_bit,uint64_t * next,QEMUTimer * timer,int tsr_bit)129 static void booke_update_fixed_timer(CPUPPCState *env,
130 uint8_t target_bit,
131 uint64_t *next,
132 QEMUTimer *timer,
133 int tsr_bit)
134 {
135 ppc_tb_t *tb_env = env->tb_env;
136 uint64_t delta_tick, ticks = 0;
137 uint64_t tb;
138 uint64_t period;
139 uint64_t now;
140
141 if (!(env->spr[SPR_BOOKE_TSR] & tsr_bit)) {
142 /*
143 * Don't arm the timer again when the guest has the current
144 * interrupt still pending. Wait for it to ack it.
145 */
146 return;
147 }
148
149 now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
150 tb = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
151 period = 1ULL << target_bit;
152 delta_tick = period - (tb & (period - 1));
153
154 /* the timer triggers only when the selected bit toggles from 0 to 1 */
155 if (tb & period) {
156 ticks = period;
157 }
158
159 if (ticks + delta_tick < ticks) {
160 /* Overflow, so assume the biggest number we can express. */
161 ticks = UINT64_MAX;
162 } else {
163 ticks += delta_tick;
164 }
165
166 *next = now + muldiv64(ticks, NANOSECONDS_PER_SECOND, tb_env->tb_freq);
167 if ((*next < now) || (*next > INT64_MAX)) {
168 /* Overflow, so assume the biggest number the qemu timer supports. */
169 *next = INT64_MAX;
170 }
171
172 /* XXX: If expire time is now. We can't run the callback because we don't
173 * have access to it. So we just set the timer one nanosecond later.
174 */
175
176 if (*next == now) {
177 (*next)++;
178 } else {
179 /*
180 * There's no point to fake any granularity that's more fine grained
181 * than milliseconds. Anything beyond that just overloads the system.
182 */
183 *next = MAX(*next, now + SCALE_MS);
184 }
185
186 /* Fire the next timer */
187 timer_mod(timer, *next);
188 }
189
booke_decr_cb(void * opaque)190 static void booke_decr_cb(void *opaque)
191 {
192 PowerPCCPU *cpu = opaque;
193 CPUPPCState *env = &cpu->env;
194
195 env->spr[SPR_BOOKE_TSR] |= TSR_DIS;
196 booke_update_irq(cpu);
197
198 if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
199 /* Do not reload 0, it is already there. It would just trigger
200 * the timer again and lead to infinite loop */
201 if (env->spr[SPR_BOOKE_DECAR] != 0) {
202 /* Auto Reload */
203 cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
204 }
205 }
206 }
207
booke_fit_cb(void * opaque)208 static void booke_fit_cb(void *opaque)
209 {
210 PowerPCCPU *cpu = opaque;
211 CPUPPCState *env = &cpu->env;
212 ppc_tb_t *tb_env;
213 booke_timer_t *booke_timer;
214
215 tb_env = env->tb_env;
216 booke_timer = tb_env->opaque;
217 env->spr[SPR_BOOKE_TSR] |= TSR_FIS;
218
219 booke_update_irq(cpu);
220
221 booke_update_fixed_timer(env,
222 booke_get_fit_target(env, tb_env),
223 &booke_timer->fit_next,
224 booke_timer->fit_timer,
225 TSR_FIS);
226 }
227
booke_wdt_cb(void * opaque)228 static void booke_wdt_cb(void *opaque)
229 {
230 PowerPCCPU *cpu = opaque;
231 CPUPPCState *env = &cpu->env;
232 ppc_tb_t *tb_env;
233 booke_timer_t *booke_timer;
234
235 tb_env = env->tb_env;
236 booke_timer = tb_env->opaque;
237
238 /* TODO: There's lots of complicated stuff to do here */
239
240 booke_update_irq(cpu);
241
242 booke_update_fixed_timer(env,
243 booke_get_wdt_target(env, tb_env),
244 &booke_timer->wdt_next,
245 booke_timer->wdt_timer,
246 TSR_WIS);
247 }
248
store_booke_tsr(CPUPPCState * env,target_ulong val)249 void store_booke_tsr(CPUPPCState *env, target_ulong val)
250 {
251 PowerPCCPU *cpu = env_archcpu(env);
252 ppc_tb_t *tb_env = env->tb_env;
253 booke_timer_t *booke_timer = tb_env->opaque;
254
255 env->spr[SPR_BOOKE_TSR] &= ~val;
256 kvmppc_clear_tsr_bits(cpu, val);
257
258 if (val & TSR_FIS) {
259 booke_update_fixed_timer(env,
260 booke_get_fit_target(env, tb_env),
261 &booke_timer->fit_next,
262 booke_timer->fit_timer,
263 TSR_FIS);
264 }
265
266 if (val & TSR_WIS) {
267 booke_update_fixed_timer(env,
268 booke_get_wdt_target(env, tb_env),
269 &booke_timer->wdt_next,
270 booke_timer->wdt_timer,
271 TSR_WIS);
272 }
273
274 booke_update_irq(cpu);
275 }
276
store_booke_tcr(CPUPPCState * env,target_ulong val)277 void store_booke_tcr(CPUPPCState *env, target_ulong val)
278 {
279 PowerPCCPU *cpu = env_archcpu(env);
280 ppc_tb_t *tb_env = env->tb_env;
281 booke_timer_t *booke_timer = tb_env->opaque;
282
283 env->spr[SPR_BOOKE_TCR] = val;
284 kvmppc_set_tcr(cpu);
285
286 booke_update_irq(cpu);
287
288 booke_update_fixed_timer(env,
289 booke_get_fit_target(env, tb_env),
290 &booke_timer->fit_next,
291 booke_timer->fit_timer,
292 TSR_FIS);
293
294 booke_update_fixed_timer(env,
295 booke_get_wdt_target(env, tb_env),
296 &booke_timer->wdt_next,
297 booke_timer->wdt_timer,
298 TSR_WIS);
299 }
300
ppc_booke_timer_reset_handle(void * opaque)301 static void ppc_booke_timer_reset_handle(void *opaque)
302 {
303 PowerPCCPU *cpu = opaque;
304 CPUPPCState *env = &cpu->env;
305
306 store_booke_tcr(env, 0);
307 store_booke_tsr(env, -1);
308 }
309
310 /*
311 * This function will be called whenever the CPU state changes.
312 * CPU states are defined "typedef enum RunState".
313 * Regarding timer, When CPU state changes to running after debug halt
314 * or similar cases which takes time then in between final watchdog
315 * expiry happenes. This will cause exit to QEMU and configured watchdog
316 * action will be taken. To avoid this we always clear the watchdog state when
317 * state changes to running.
318 */
cpu_state_change_handler(void * opaque,bool running,RunState state)319 static void cpu_state_change_handler(void *opaque, bool running, RunState state)
320 {
321 PowerPCCPU *cpu = opaque;
322 CPUPPCState *env = &cpu->env;
323
324 if (!running) {
325 return;
326 }
327
328 /*
329 * Clear watchdog interrupt condition by clearing TSR.
330 */
331 store_booke_tsr(env, TSR_ENW | TSR_WIS | TSR_WRS_MASK);
332 }
333
ppc_booke_timers_init(PowerPCCPU * cpu,uint32_t freq,uint32_t flags)334 void ppc_booke_timers_init(PowerPCCPU *cpu, uint32_t freq, uint32_t flags)
335 {
336 ppc_tb_t *tb_env;
337 booke_timer_t *booke_timer;
338 int ret = 0;
339
340 tb_env = g_new0(ppc_tb_t, 1);
341 booke_timer = g_new0(booke_timer_t, 1);
342
343 cpu->env.tb_env = tb_env;
344 tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;
345
346 tb_env->tb_freq = freq;
347 tb_env->decr_freq = freq;
348 tb_env->opaque = booke_timer;
349 tb_env->decr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_decr_cb, cpu);
350
351 booke_timer->fit_timer =
352 timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_fit_cb, cpu);
353 booke_timer->wdt_timer =
354 timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_wdt_cb, cpu);
355
356 ret = kvmppc_booke_watchdog_enable(cpu);
357
358 if (ret) {
359 /* TODO: Start the QEMU emulated watchdog if not running on KVM.
360 * Also start the QEMU emulated watchdog if KVM does not support
361 * emulated watchdog or somehow it is not enabled (supported but
362 * not enabled is though some bug and requires debugging :)).
363 */
364 }
365
366 qemu_add_vm_change_state_handler(cpu_state_change_handler, cpu);
367
368 qemu_register_reset(ppc_booke_timer_reset_handle, cpu);
369 }
370