xref: /openbmc/qemu/hw/ppc/ppc_booke.c (revision 2993683b)
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 #include "hw/hw.h"
25 #include "hw/ppc/ppc.h"
26 #include "qemu/timer.h"
27 #include "sysemu/sysemu.h"
28 #include "hw/timer/m48t59.h"
29 #include "qemu/log.h"
30 #include "hw/loader.h"
31 #include "kvm_ppc.h"
32 
33 
34 /* Timer Control Register */
35 
36 #define TCR_WP_SHIFT  30        /* Watchdog Timer Period */
37 #define TCR_WP_MASK   (0x3 << TCR_WP_SHIFT)
38 #define TCR_WRC_SHIFT 28        /* Watchdog Timer Reset Control */
39 #define TCR_WRC_MASK  (0x3 << TCR_WRC_SHIFT)
40 #define TCR_WIE       (1 << 27) /* Watchdog Timer Interrupt Enable */
41 #define TCR_DIE       (1 << 26) /* Decrementer Interrupt Enable */
42 #define TCR_FP_SHIFT  24        /* Fixed-Interval Timer Period */
43 #define TCR_FP_MASK   (0x3 << TCR_FP_SHIFT)
44 #define TCR_FIE       (1 << 23) /* Fixed-Interval Timer Interrupt Enable */
45 #define TCR_ARE       (1 << 22) /* Auto-Reload Enable */
46 
47 /* Timer Control Register (e500 specific fields) */
48 
49 #define TCR_E500_FPEXT_SHIFT 13 /* Fixed-Interval Timer Period Extension */
50 #define TCR_E500_FPEXT_MASK  (0xf << TCR_E500_FPEXT_SHIFT)
51 #define TCR_E500_WPEXT_SHIFT 17 /* Watchdog Timer Period Extension */
52 #define TCR_E500_WPEXT_MASK  (0xf << TCR_E500_WPEXT_SHIFT)
53 
54 /* Timer Status Register  */
55 
56 #define TSR_FIS       (1 << 26) /* Fixed-Interval Timer Interrupt Status */
57 #define TSR_DIS       (1 << 27) /* Decrementer Interrupt Status */
58 #define TSR_WRS_SHIFT 28        /* Watchdog Timer Reset Status */
59 #define TSR_WRS_MASK  (0x3 << TSR_WRS_SHIFT)
60 #define TSR_WIS       (1 << 30) /* Watchdog Timer Interrupt Status */
61 #define TSR_ENW       (1 << 31) /* Enable Next Watchdog Timer */
62 
63 typedef struct booke_timer_t booke_timer_t;
64 struct booke_timer_t {
65 
66     uint64_t fit_next;
67     struct QEMUTimer *fit_timer;
68 
69     uint64_t wdt_next;
70     struct QEMUTimer *wdt_timer;
71 
72     uint32_t flags;
73 };
74 
75 static void booke_update_irq(PowerPCCPU *cpu)
76 {
77     CPUPPCState *env = &cpu->env;
78 
79     ppc_set_irq(cpu, PPC_INTERRUPT_DECR,
80                 (env->spr[SPR_BOOKE_TSR] & TSR_DIS
81                  && env->spr[SPR_BOOKE_TCR] & TCR_DIE));
82 
83     ppc_set_irq(cpu, PPC_INTERRUPT_WDT,
84                 (env->spr[SPR_BOOKE_TSR] & TSR_WIS
85                  && env->spr[SPR_BOOKE_TCR] & TCR_WIE));
86 
87     ppc_set_irq(cpu, PPC_INTERRUPT_FIT,
88                 (env->spr[SPR_BOOKE_TSR] & TSR_FIS
89                  && env->spr[SPR_BOOKE_TCR] & TCR_FIE));
90 }
91 
92 /* Return the location of the bit of time base at which the FIT will raise an
93    interrupt */
94 static uint8_t booke_get_fit_target(CPUPPCState *env, ppc_tb_t *tb_env)
95 {
96     uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;
97 
98     if (tb_env->flags & PPC_TIMER_E500) {
99         /* e500 Fixed-interval timer period extension */
100         uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
101             >> TCR_E500_FPEXT_SHIFT;
102         fp = 63 - (fp | fpext << 2);
103     } else {
104         fp = env->fit_period[fp];
105     }
106 
107     return fp;
108 }
109 
110 /* Return the location of the bit of time base at which the WDT will raise an
111    interrupt */
112 static uint8_t booke_get_wdt_target(CPUPPCState *env, ppc_tb_t *tb_env)
113 {
114     uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;
115 
116     if (tb_env->flags & PPC_TIMER_E500) {
117         /* e500 Watchdog timer period extension */
118         uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
119             >> TCR_E500_WPEXT_SHIFT;
120         wp = 63 - (wp | wpext << 2);
121     } else {
122         wp = env->wdt_period[wp];
123     }
124 
125     return wp;
126 }
127 
128 static void booke_update_fixed_timer(CPUPPCState         *env,
129                                      uint8_t           target_bit,
130                                      uint64_t          *next,
131                                      struct QEMUTimer *timer)
132 {
133     ppc_tb_t *tb_env = env->tb_env;
134     uint64_t lapse;
135     uint64_t tb;
136     uint64_t period = 1 << (target_bit + 1);
137     uint64_t now;
138 
139     now = qemu_get_clock_ns(vm_clock);
140     tb  = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
141 
142     lapse = period - ((tb - (1 << target_bit)) & (period - 1));
143 
144     *next = now + muldiv64(lapse, get_ticks_per_sec(), tb_env->tb_freq);
145 
146     /* XXX: If expire time is now. We can't run the callback because we don't
147      * have access to it. So we just set the timer one nanosecond later.
148      */
149 
150     if (*next == now) {
151         (*next)++;
152     }
153 
154     qemu_mod_timer(timer, *next);
155 }
156 
157 static void booke_decr_cb(void *opaque)
158 {
159     PowerPCCPU *cpu = opaque;
160     CPUPPCState *env = &cpu->env;
161 
162     env->spr[SPR_BOOKE_TSR] |= TSR_DIS;
163     booke_update_irq(cpu);
164 
165     if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
166         /* Auto Reload */
167         cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
168     }
169 }
170 
171 static void booke_fit_cb(void *opaque)
172 {
173     PowerPCCPU *cpu = opaque;
174     CPUPPCState *env = &cpu->env;
175     ppc_tb_t *tb_env;
176     booke_timer_t *booke_timer;
177 
178     tb_env = env->tb_env;
179     booke_timer = tb_env->opaque;
180     env->spr[SPR_BOOKE_TSR] |= TSR_FIS;
181 
182     booke_update_irq(cpu);
183 
184     booke_update_fixed_timer(env,
185                              booke_get_fit_target(env, tb_env),
186                              &booke_timer->fit_next,
187                              booke_timer->fit_timer);
188 }
189 
190 static void booke_wdt_cb(void *opaque)
191 {
192     PowerPCCPU *cpu = opaque;
193     CPUPPCState *env = &cpu->env;
194     ppc_tb_t *tb_env;
195     booke_timer_t *booke_timer;
196 
197     tb_env = env->tb_env;
198     booke_timer = tb_env->opaque;
199 
200     /* TODO: There's lots of complicated stuff to do here */
201 
202     booke_update_irq(cpu);
203 
204     booke_update_fixed_timer(env,
205                              booke_get_wdt_target(env, tb_env),
206                              &booke_timer->wdt_next,
207                              booke_timer->wdt_timer);
208 }
209 
210 void store_booke_tsr(CPUPPCState *env, target_ulong val)
211 {
212     PowerPCCPU *cpu = ppc_env_get_cpu(env);
213 
214     env->spr[SPR_BOOKE_TSR] &= ~val;
215     kvmppc_clear_tsr_bits(cpu, val);
216     booke_update_irq(cpu);
217 }
218 
219 void store_booke_tcr(CPUPPCState *env, target_ulong val)
220 {
221     PowerPCCPU *cpu = ppc_env_get_cpu(env);
222     ppc_tb_t *tb_env = env->tb_env;
223     booke_timer_t *booke_timer = tb_env->opaque;
224 
225     tb_env = env->tb_env;
226     env->spr[SPR_BOOKE_TCR] = val;
227     kvmppc_set_tcr(cpu);
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 
236     booke_update_fixed_timer(env,
237                              booke_get_wdt_target(env, tb_env),
238                              &booke_timer->wdt_next,
239                              booke_timer->wdt_timer);
240 }
241 
242 static void ppc_booke_timer_reset_handle(void *opaque)
243 {
244     PowerPCCPU *cpu = opaque;
245     CPUPPCState *env = &cpu->env;
246 
247     store_booke_tcr(env, 0);
248     store_booke_tsr(env, -1);
249 }
250 
251 /*
252  * This function will be called whenever the CPU state changes.
253  * CPU states are defined "typedef enum RunState".
254  * Regarding timer, When CPU state changes to running after debug halt
255  * or similar cases which takes time then in between final watchdog
256  * expiry happenes. This will cause exit to QEMU and configured watchdog
257  * action will be taken. To avoid this we always clear the watchdog state when
258  * state changes to running.
259  */
260 static void cpu_state_change_handler(void *opaque, int running, RunState state)
261 {
262     PowerPCCPU *cpu = opaque;
263     CPUPPCState *env = &cpu->env;
264 
265     if (!running) {
266         return;
267     }
268 
269     /*
270      * Clear watchdog interrupt condition by clearing TSR.
271      */
272     store_booke_tsr(env, TSR_ENW | TSR_WIS | TSR_WRS_MASK);
273 }
274 
275 void ppc_booke_timers_init(PowerPCCPU *cpu, uint32_t freq, uint32_t flags)
276 {
277     ppc_tb_t *tb_env;
278     booke_timer_t *booke_timer;
279     int ret = 0;
280 
281     tb_env      = g_malloc0(sizeof(ppc_tb_t));
282     booke_timer = g_malloc0(sizeof(booke_timer_t));
283 
284     cpu->env.tb_env = tb_env;
285     tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;
286 
287     tb_env->tb_freq    = freq;
288     tb_env->decr_freq  = freq;
289     tb_env->opaque     = booke_timer;
290     tb_env->decr_timer = qemu_new_timer_ns(vm_clock, &booke_decr_cb, cpu);
291 
292     booke_timer->fit_timer =
293         qemu_new_timer_ns(vm_clock, &booke_fit_cb, cpu);
294     booke_timer->wdt_timer =
295         qemu_new_timer_ns(vm_clock, &booke_wdt_cb, cpu);
296 
297     ret = kvmppc_booke_watchdog_enable(cpu);
298 
299     if (ret) {
300         /* TODO: Start the QEMU emulated watchdog if not running on KVM.
301          * Also start the QEMU emulated watchdog if KVM does not support
302          * emulated watchdog or somehow it is not enabled (supported but
303          * not enabled is though some bug and requires debugging :)).
304          */
305     }
306 
307     qemu_add_vm_change_state_handler(cpu_state_change_handler, cpu);
308 
309     qemu_register_reset(ppc_booke_timer_reset_handle, cpu);
310 }
311