xref: /openbmc/qemu/target/hppa/int_helper.c (revision 464dacf6)
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     int le_bit = ~data & (TARGET_REGISTER_BITS - 1);
56 
57     cpu->env.cr[CR_EIRR] |= (target_ureg)1 << le_bit;
58     eval_interrupt(cpu);
59 }
60 
61 const MemoryRegionOps hppa_io_eir_ops = {
62     .read = io_eir_read,
63     .write = io_eir_write,
64     .valid.min_access_size = 4,
65     .valid.max_access_size = 4,
66     .impl.min_access_size = 4,
67     .impl.max_access_size = 4,
68 };
69 
70 void hppa_cpu_alarm_timer(void *opaque)
71 {
72     /* Raise interrupt 0.  */
73     io_eir_write(opaque, 0, 0, 4);
74 }
75 
76 void HELPER(write_eirr)(CPUHPPAState *env, target_ureg val)
77 {
78     env->cr[CR_EIRR] &= ~val;
79     qemu_mutex_lock_iothread();
80     eval_interrupt(env_archcpu(env));
81     qemu_mutex_unlock_iothread();
82 }
83 
84 void HELPER(write_eiem)(CPUHPPAState *env, target_ureg val)
85 {
86     env->cr[CR_EIEM] = val;
87     qemu_mutex_lock_iothread();
88     eval_interrupt(env_archcpu(env));
89     qemu_mutex_unlock_iothread();
90 }
91 
92 void hppa_cpu_do_interrupt(CPUState *cs)
93 {
94     HPPACPU *cpu = HPPA_CPU(cs);
95     CPUHPPAState *env = &cpu->env;
96     int i = cs->exception_index;
97     target_ureg iaoq_f = env->iaoq_f;
98     target_ureg iaoq_b = env->iaoq_b;
99     uint64_t iasq_f = env->iasq_f;
100     uint64_t iasq_b = env->iasq_b;
101 
102     target_ureg old_psw;
103 
104     /* As documented in pa2.0 -- interruption handling.  */
105     /* step 1 */
106     env->cr[CR_IPSW] = old_psw = cpu_hppa_get_psw(env);
107 
108     /* step 2 -- note PSW_W == 0 for !HPPA64.  */
109     cpu_hppa_put_psw(env, PSW_W | (i == EXCP_HPMC ? PSW_M : 0));
110 
111     /* step 3 */
112     env->cr[CR_IIASQ] = iasq_f >> 32;
113     env->cr_back[0] = iasq_b >> 32;
114     env->cr[CR_IIAOQ] = iaoq_f;
115     env->cr_back[1] = iaoq_b;
116 
117     if (old_psw & PSW_Q) {
118         /* step 5 */
119         /* ISR and IOR will be set elsewhere.  */
120         switch (i) {
121         case EXCP_ILL:
122         case EXCP_BREAK:
123         case EXCP_PRIV_REG:
124         case EXCP_PRIV_OPR:
125             /* IIR set via translate.c.  */
126             break;
127 
128         case EXCP_OVERFLOW:
129         case EXCP_COND:
130         case EXCP_ASSIST:
131         case EXCP_DTLB_MISS:
132         case EXCP_NA_ITLB_MISS:
133         case EXCP_NA_DTLB_MISS:
134         case EXCP_DMAR:
135         case EXCP_DMPI:
136         case EXCP_UNALIGN:
137         case EXCP_DMP:
138         case EXCP_DMB:
139         case EXCP_TLB_DIRTY:
140         case EXCP_PAGE_REF:
141         case EXCP_ASSIST_EMU:
142             {
143                 /* Avoid reading directly from the virtual address, lest we
144                    raise another exception from some sort of TLB issue.  */
145                 /* ??? An alternate fool-proof method would be to store the
146                    instruction data into the unwind info.  That's probably
147                    a bit too much in the way of extra storage required.  */
148                 vaddr vaddr;
149                 hwaddr paddr;
150 
151                 paddr = vaddr = iaoq_f & -4;
152                 if (old_psw & PSW_C) {
153                     int prot, t;
154 
155                     vaddr = hppa_form_gva_psw(old_psw, iasq_f, vaddr);
156                     t = hppa_get_physical_address(env, vaddr, MMU_KERNEL_IDX,
157                                                   0, &paddr, &prot, NULL);
158                     if (t >= 0) {
159                         /* We can't re-load the instruction.  */
160                         env->cr[CR_IIR] = 0;
161                         break;
162                     }
163                 }
164                 env->cr[CR_IIR] = ldl_phys(cs->as, paddr);
165             }
166             break;
167 
168         default:
169             /* Other exceptions do not set IIR.  */
170             break;
171         }
172 
173         /* step 6 */
174         env->shadow[0] = env->gr[1];
175         env->shadow[1] = env->gr[8];
176         env->shadow[2] = env->gr[9];
177         env->shadow[3] = env->gr[16];
178         env->shadow[4] = env->gr[17];
179         env->shadow[5] = env->gr[24];
180         env->shadow[6] = env->gr[25];
181     }
182 
183     /* step 7 */
184     if (i == EXCP_TOC) {
185         env->iaoq_f = FIRMWARE_START;
186         /* help SeaBIOS and provide iaoq_b and iasq_back in shadow regs */
187         env->gr[24] = env->cr_back[0];
188         env->gr[25] = env->cr_back[1];
189     } else {
190         env->iaoq_f = env->cr[CR_IVA] + 32 * i;
191     }
192     env->iaoq_b = env->iaoq_f + 4;
193     env->iasq_f = 0;
194     env->iasq_b = 0;
195 
196     if (qemu_loglevel_mask(CPU_LOG_INT)) {
197         static const char * const names[] = {
198             [EXCP_HPMC]          = "high priority machine check",
199             [EXCP_POWER_FAIL]    = "power fail interrupt",
200             [EXCP_RC]            = "recovery counter trap",
201             [EXCP_EXT_INTERRUPT] = "external interrupt",
202             [EXCP_LPMC]          = "low priority machine check",
203             [EXCP_ITLB_MISS]     = "instruction tlb miss fault",
204             [EXCP_IMP]           = "instruction memory protection trap",
205             [EXCP_ILL]           = "illegal instruction trap",
206             [EXCP_BREAK]         = "break instruction trap",
207             [EXCP_PRIV_OPR]      = "privileged operation trap",
208             [EXCP_PRIV_REG]      = "privileged register trap",
209             [EXCP_OVERFLOW]      = "overflow trap",
210             [EXCP_COND]          = "conditional trap",
211             [EXCP_ASSIST]        = "assist exception trap",
212             [EXCP_DTLB_MISS]     = "data tlb miss fault",
213             [EXCP_NA_ITLB_MISS]  = "non-access instruction tlb miss",
214             [EXCP_NA_DTLB_MISS]  = "non-access data tlb miss",
215             [EXCP_DMP]           = "data memory protection trap",
216             [EXCP_DMB]           = "data memory break trap",
217             [EXCP_TLB_DIRTY]     = "tlb dirty bit trap",
218             [EXCP_PAGE_REF]      = "page reference trap",
219             [EXCP_ASSIST_EMU]    = "assist emulation trap",
220             [EXCP_HPT]           = "high-privilege transfer trap",
221             [EXCP_LPT]           = "low-privilege transfer trap",
222             [EXCP_TB]            = "taken branch trap",
223             [EXCP_DMAR]          = "data memory access rights trap",
224             [EXCP_DMPI]          = "data memory protection id trap",
225             [EXCP_UNALIGN]       = "unaligned data reference trap",
226             [EXCP_PER_INTERRUPT] = "performance monitor interrupt",
227             [EXCP_SYSCALL]       = "syscall",
228             [EXCP_SYSCALL_LWS]   = "syscall-lws",
229             [EXCP_TOC]           = "TOC (transfer of control)",
230         };
231         static int count;
232         const char *name = NULL;
233         char unknown[16];
234 
235         if (i >= 0 && i < ARRAY_SIZE(names)) {
236             name = names[i];
237         }
238         if (!name) {
239             snprintf(unknown, sizeof(unknown), "unknown %d", i);
240             name = unknown;
241         }
242         qemu_log("INT %6d: %s @ " TARGET_FMT_lx "," TARGET_FMT_lx
243                  " -> " TREG_FMT_lx " " TARGET_FMT_lx "\n",
244                  ++count, name,
245                  hppa_form_gva(env, iasq_f, iaoq_f),
246                  hppa_form_gva(env, iasq_b, iaoq_b),
247                  env->iaoq_f,
248                  hppa_form_gva(env, (uint64_t)env->cr[CR_ISR] << 32,
249                                env->cr[CR_IOR]));
250     }
251     cs->exception_index = -1;
252 }
253 
254 bool hppa_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
255 {
256     HPPACPU *cpu = HPPA_CPU(cs);
257     CPUHPPAState *env = &cpu->env;
258 
259     if (interrupt_request & CPU_INTERRUPT_NMI) {
260         /* Raise TOC (NMI) interrupt */
261         cpu_reset_interrupt(cs, CPU_INTERRUPT_NMI);
262         cs->exception_index = EXCP_TOC;
263         hppa_cpu_do_interrupt(cs);
264         return true;
265     }
266 
267     /* If interrupts are requested and enabled, raise them.  */
268     if ((env->psw & PSW_I) && (interrupt_request & CPU_INTERRUPT_HARD)) {
269         cs->exception_index = EXCP_EXT_INTERRUPT;
270         hppa_cpu_do_interrupt(cs);
271         return true;
272     }
273     return false;
274 }
275