xref: /openbmc/qemu/target/hppa/int_helper.c (revision 7200fb21)
1 /*
2  *  HPPA interrupt helper routines
3  *
4  *  Copyright (c) 2017 Richard Henderson
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 
20 #include "qemu/osdep.h"
21 #include "qemu/main-loop.h"
22 #include "qemu/log.h"
23 #include "cpu.h"
24 #include "exec/helper-proto.h"
25 #include "hw/core/cpu.h"
26 #include "hw/hppa/hppa_hardware.h"
27 
28 static void eval_interrupt(HPPACPU *cpu)
29 {
30     CPUState *cs = CPU(cpu);
31     if (cpu->env.cr[CR_EIRR] & cpu->env.cr[CR_EIEM]) {
32         cpu_interrupt(cs, CPU_INTERRUPT_HARD);
33     } else {
34         cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
35     }
36 }
37 
38 /* Each CPU has a word mapped into the GSC bus.  Anything on the GSC bus
39  * can write to this word to raise an external interrupt on the target CPU.
40  * This includes the system controller (DINO) for regular devices, or
41  * another CPU for SMP interprocessor interrupts.
42  */
43 static uint64_t io_eir_read(void *opaque, hwaddr addr, unsigned size)
44 {
45     HPPACPU *cpu = opaque;
46 
47     /* ??? What does a read of this register over the GSC bus do?  */
48     return cpu->env.cr[CR_EIRR];
49 }
50 
51 static void io_eir_write(void *opaque, hwaddr addr,
52                          uint64_t data, unsigned size)
53 {
54     HPPACPU *cpu = opaque;
55     CPUHPPAState *env = &cpu->env;
56     int widthm1 = 31;
57     int le_bit;
58 
59     /* The default PSW.W controls the width of EIRR. */
60     if (hppa_is_pa20(env) && env->cr[CR_PSW_DEFAULT] & PDC_PSW_WIDE_BIT) {
61         widthm1 = 63;
62     }
63     le_bit = ~data & widthm1;
64 
65     env->cr[CR_EIRR] |= 1ull << le_bit;
66     eval_interrupt(cpu);
67 }
68 
69 const MemoryRegionOps hppa_io_eir_ops = {
70     .read = io_eir_read,
71     .write = io_eir_write,
72     .valid.min_access_size = 4,
73     .valid.max_access_size = 4,
74     .impl.min_access_size = 4,
75     .impl.max_access_size = 4,
76 };
77 
78 void hppa_cpu_alarm_timer(void *opaque)
79 {
80     /* Raise interrupt 0.  */
81     io_eir_write(opaque, 0, 0, 4);
82 }
83 
84 void HELPER(write_eirr)(CPUHPPAState *env, target_ulong val)
85 {
86     env->cr[CR_EIRR] &= ~val;
87     qemu_mutex_lock_iothread();
88     eval_interrupt(env_archcpu(env));
89     qemu_mutex_unlock_iothread();
90 }
91 
92 void HELPER(write_eiem)(CPUHPPAState *env, target_ulong val)
93 {
94     env->cr[CR_EIEM] = val;
95     qemu_mutex_lock_iothread();
96     eval_interrupt(env_archcpu(env));
97     qemu_mutex_unlock_iothread();
98 }
99 
100 void hppa_cpu_do_interrupt(CPUState *cs)
101 {
102     HPPACPU *cpu = HPPA_CPU(cs);
103     CPUHPPAState *env = &cpu->env;
104     int i = cs->exception_index;
105     uint64_t old_psw;
106 
107     /* As documented in pa2.0 -- interruption handling.  */
108     /* step 1 */
109     env->cr[CR_IPSW] = old_psw = cpu_hppa_get_psw(env);
110 
111     /* step 2 -- Note PSW_W is masked out again for pa1.x */
112     cpu_hppa_put_psw(env,
113                      (env->cr[CR_PSW_DEFAULT] & PDC_PSW_WIDE_BIT ? PSW_W : 0) |
114                      (i == EXCP_HPMC ? PSW_M : 0));
115 
116     /* step 3 */
117     /*
118      * For pa1.x, IIASQ is simply a copy of IASQ.
119      * For pa2.0, IIASQ is the top bits of the virtual address,
120      *            or zero if translation is disabled.
121      */
122     if (!hppa_is_pa20(env)) {
123         env->cr[CR_IIASQ] = env->iasq_f >> 32;
124         env->cr_back[0] = env->iasq_b >> 32;
125     } else if (old_psw & PSW_C) {
126         env->cr[CR_IIASQ] =
127             hppa_form_gva_psw(old_psw, env->iasq_f, env->iaoq_f) >> 32;
128         env->cr_back[0] =
129             hppa_form_gva_psw(old_psw, env->iasq_b, env->iaoq_b) >> 32;
130     } else {
131         env->cr[CR_IIASQ] = 0;
132         env->cr_back[0] = 0;
133     }
134     env->cr[CR_IIAOQ] = env->iaoq_f;
135     env->cr_back[1] = env->iaoq_b;
136 
137     if (old_psw & PSW_Q) {
138         /* step 5 */
139         /* ISR and IOR will be set elsewhere.  */
140         switch (i) {
141         case EXCP_ILL:
142         case EXCP_BREAK:
143         case EXCP_PRIV_REG:
144         case EXCP_PRIV_OPR:
145             /* IIR set via translate.c.  */
146             break;
147 
148         case EXCP_OVERFLOW:
149         case EXCP_COND:
150         case EXCP_ASSIST:
151         case EXCP_DTLB_MISS:
152         case EXCP_NA_ITLB_MISS:
153         case EXCP_NA_DTLB_MISS:
154         case EXCP_DMAR:
155         case EXCP_DMPI:
156         case EXCP_UNALIGN:
157         case EXCP_DMP:
158         case EXCP_DMB:
159         case EXCP_TLB_DIRTY:
160         case EXCP_PAGE_REF:
161         case EXCP_ASSIST_EMU:
162             {
163                 /* Avoid reading directly from the virtual address, lest we
164                    raise another exception from some sort of TLB issue.  */
165                 /* ??? An alternate fool-proof method would be to store the
166                    instruction data into the unwind info.  That's probably
167                    a bit too much in the way of extra storage required.  */
168                 vaddr vaddr = env->iaoq_f & -4;
169                 hwaddr paddr = vaddr;
170 
171                 if (old_psw & PSW_C) {
172                     int prot, t;
173 
174                     vaddr = hppa_form_gva_psw(old_psw, env->iasq_f, vaddr);
175                     t = hppa_get_physical_address(env, vaddr, MMU_KERNEL_IDX,
176                                                   0, &paddr, &prot, NULL);
177                     if (t >= 0) {
178                         /* We can't re-load the instruction.  */
179                         env->cr[CR_IIR] = 0;
180                         break;
181                     }
182                 }
183                 env->cr[CR_IIR] = ldl_phys(cs->as, paddr);
184             }
185             break;
186 
187         default:
188             /* Other exceptions do not set IIR.  */
189             break;
190         }
191 
192         /* step 6 */
193         env->shadow[0] = env->gr[1];
194         env->shadow[1] = env->gr[8];
195         env->shadow[2] = env->gr[9];
196         env->shadow[3] = env->gr[16];
197         env->shadow[4] = env->gr[17];
198         env->shadow[5] = env->gr[24];
199         env->shadow[6] = env->gr[25];
200     }
201 
202     /* step 7 */
203     if (i == EXCP_TOC) {
204         env->iaoq_f = hppa_form_gva(env, 0, FIRMWARE_START);
205         /* help SeaBIOS and provide iaoq_b and iasq_back in shadow regs */
206         env->gr[24] = env->cr_back[0];
207         env->gr[25] = env->cr_back[1];
208     } else {
209         env->iaoq_f = hppa_form_gva(env, 0, env->cr[CR_IVA] + 32 * i);
210     }
211     env->iaoq_b = hppa_form_gva(env, 0, env->iaoq_f + 4);
212     env->iasq_f = 0;
213     env->iasq_b = 0;
214 
215     if (qemu_loglevel_mask(CPU_LOG_INT)) {
216         static const char * const names[] = {
217             [EXCP_HPMC]          = "high priority machine check",
218             [EXCP_POWER_FAIL]    = "power fail interrupt",
219             [EXCP_RC]            = "recovery counter trap",
220             [EXCP_EXT_INTERRUPT] = "external interrupt",
221             [EXCP_LPMC]          = "low priority machine check",
222             [EXCP_ITLB_MISS]     = "instruction tlb miss fault",
223             [EXCP_IMP]           = "instruction memory protection trap",
224             [EXCP_ILL]           = "illegal instruction trap",
225             [EXCP_BREAK]         = "break instruction trap",
226             [EXCP_PRIV_OPR]      = "privileged operation trap",
227             [EXCP_PRIV_REG]      = "privileged register trap",
228             [EXCP_OVERFLOW]      = "overflow trap",
229             [EXCP_COND]          = "conditional trap",
230             [EXCP_ASSIST]        = "assist exception trap",
231             [EXCP_DTLB_MISS]     = "data tlb miss fault",
232             [EXCP_NA_ITLB_MISS]  = "non-access instruction tlb miss",
233             [EXCP_NA_DTLB_MISS]  = "non-access data tlb miss",
234             [EXCP_DMP]           = "data memory protection trap",
235             [EXCP_DMB]           = "data memory break trap",
236             [EXCP_TLB_DIRTY]     = "tlb dirty bit trap",
237             [EXCP_PAGE_REF]      = "page reference trap",
238             [EXCP_ASSIST_EMU]    = "assist emulation trap",
239             [EXCP_HPT]           = "high-privilege transfer trap",
240             [EXCP_LPT]           = "low-privilege transfer trap",
241             [EXCP_TB]            = "taken branch trap",
242             [EXCP_DMAR]          = "data memory access rights trap",
243             [EXCP_DMPI]          = "data memory protection id trap",
244             [EXCP_UNALIGN]       = "unaligned data reference trap",
245             [EXCP_PER_INTERRUPT] = "performance monitor interrupt",
246             [EXCP_SYSCALL]       = "syscall",
247             [EXCP_SYSCALL_LWS]   = "syscall-lws",
248             [EXCP_TOC]           = "TOC (transfer of control)",
249         };
250         static int count;
251         const char *name = NULL;
252         char unknown[16];
253 
254         if (i >= 0 && i < ARRAY_SIZE(names)) {
255             name = names[i];
256         }
257         if (!name) {
258             snprintf(unknown, sizeof(unknown), "unknown %d", i);
259             name = unknown;
260         }
261         qemu_log("INT %6d: %s @ " TARGET_FMT_lx ":" TARGET_FMT_lx
262                  " for " TARGET_FMT_lx ":" TARGET_FMT_lx "\n",
263                  ++count, name, env->cr[CR_IIASQ], env->cr[CR_IIAOQ],
264                  env->cr[CR_ISR], env->cr[CR_IOR]);
265     }
266     cs->exception_index = -1;
267 }
268 
269 bool hppa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
270 {
271     HPPACPU *cpu = HPPA_CPU(cs);
272     CPUHPPAState *env = &cpu->env;
273 
274     if (interrupt_request & CPU_INTERRUPT_NMI) {
275         /* Raise TOC (NMI) interrupt */
276         cpu_reset_interrupt(cs, CPU_INTERRUPT_NMI);
277         cs->exception_index = EXCP_TOC;
278         hppa_cpu_do_interrupt(cs);
279         return true;
280     }
281 
282     /* If interrupts are requested and enabled, raise them.  */
283     if ((env->psw & PSW_I) && (interrupt_request & CPU_INTERRUPT_HARD)) {
284         cs->exception_index = EXCP_EXT_INTERRUPT;
285         hppa_cpu_do_interrupt(cs);
286         return true;
287     }
288     return false;
289 }
290