xref: /openbmc/qemu/target/microblaze/helper.c (revision c63ca4ff)
1 /*
2  *  MicroBlaze helper routines.
3  *
4  *  Copyright (c) 2009 Edgar E. Iglesias <edgar.iglesias@gmail.com>
5  *  Copyright (c) 2009-2012 PetaLogix Qld Pty Ltd.
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "exec/exec-all.h"
24 #include "qemu/host-utils.h"
25 #include "exec/log.h"
26 
27 #if defined(CONFIG_USER_ONLY)
28 
29 void mb_cpu_do_interrupt(CPUState *cs)
30 {
31     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
32     CPUMBState *env = &cpu->env;
33 
34     cs->exception_index = -1;
35     env->res_addr = RES_ADDR_NONE;
36     env->regs[14] = env->pc;
37 }
38 
39 bool mb_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
40                      MMUAccessType access_type, int mmu_idx,
41                      bool probe, uintptr_t retaddr)
42 {
43     cs->exception_index = 0xaa;
44     cpu_loop_exit_restore(cs, retaddr);
45 }
46 
47 #else /* !CONFIG_USER_ONLY */
48 
49 bool mb_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
50                      MMUAccessType access_type, int mmu_idx,
51                      bool probe, uintptr_t retaddr)
52 {
53     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
54     CPUMBState *env = &cpu->env;
55     MicroBlazeMMULookup lu;
56     unsigned int hit;
57     int prot;
58 
59     if (mmu_idx == MMU_NOMMU_IDX) {
60         /* MMU disabled or not available.  */
61         address &= TARGET_PAGE_MASK;
62         prot = PAGE_BITS;
63         tlb_set_page(cs, address, address, prot, mmu_idx, TARGET_PAGE_SIZE);
64         return true;
65     }
66 
67     hit = mmu_translate(cpu, &lu, address, access_type, mmu_idx);
68     if (likely(hit)) {
69         uint32_t vaddr = address & TARGET_PAGE_MASK;
70         uint32_t paddr = lu.paddr + vaddr - lu.vaddr;
71 
72         qemu_log_mask(CPU_LOG_MMU, "MMU map mmu=%d v=%x p=%x prot=%x\n",
73                       mmu_idx, vaddr, paddr, lu.prot);
74         tlb_set_page(cs, vaddr, paddr, lu.prot, mmu_idx, TARGET_PAGE_SIZE);
75         return true;
76     }
77 
78     /* TLB miss.  */
79     if (probe) {
80         return false;
81     }
82 
83     qemu_log_mask(CPU_LOG_MMU, "mmu=%d miss v=%" VADDR_PRIx "\n",
84                   mmu_idx, address);
85 
86     env->ear = address;
87     switch (lu.err) {
88     case ERR_PROT:
89         env->esr = access_type == MMU_INST_FETCH ? 17 : 16;
90         env->esr |= (access_type == MMU_DATA_STORE) << 10;
91         break;
92     case ERR_MISS:
93         env->esr = access_type == MMU_INST_FETCH ? 19 : 18;
94         env->esr |= (access_type == MMU_DATA_STORE) << 10;
95         break;
96     default:
97         abort();
98     }
99 
100     if (cs->exception_index == EXCP_MMU) {
101         cpu_abort(cs, "recursive faults\n");
102     }
103 
104     /* TLB miss.  */
105     cs->exception_index = EXCP_MMU;
106     cpu_loop_exit_restore(cs, retaddr);
107 }
108 
109 void mb_cpu_do_interrupt(CPUState *cs)
110 {
111     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
112     CPUMBState *env = &cpu->env;
113     uint32_t t, msr = mb_cpu_read_msr(env);
114     bool set_esr;
115 
116     /* IMM flag cannot propagate across a branch and into the dslot.  */
117     assert((env->iflags & (D_FLAG | IMM_FLAG)) != (D_FLAG | IMM_FLAG));
118     /* BIMM flag cannot be set without D_FLAG. */
119     assert((env->iflags & (D_FLAG | BIMM_FLAG)) != BIMM_FLAG);
120     /* RTI flags are private to translate. */
121     assert(!(env->iflags & (DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)));
122 
123     switch (cs->exception_index) {
124     case EXCP_HW_EXCP:
125         if (!(cpu->cfg.pvr_regs[0] & PVR0_USE_EXC_MASK)) {
126             qemu_log_mask(LOG_GUEST_ERROR,
127                           "Exception raised on system without exceptions!\n");
128             return;
129         }
130 
131         qemu_log_mask(CPU_LOG_INT,
132                       "INT: HWE at pc=%08x msr=%08x iflags=%x\n",
133                       env->pc, msr, env->iflags);
134 
135         /* Exception breaks branch + dslot sequence?  */
136         set_esr = true;
137         env->esr &= ~D_FLAG;
138         if (env->iflags & D_FLAG) {
139             env->esr |= D_FLAG;
140             env->btr = env->btarget;
141         }
142 
143         /* Exception in progress. */
144         msr |= MSR_EIP;
145         env->regs[17] = env->pc + 4;
146         env->pc = cpu->cfg.base_vectors + 0x20;
147         break;
148 
149     case EXCP_MMU:
150         qemu_log_mask(CPU_LOG_INT,
151                       "INT: MMU at pc=%08x msr=%08x "
152                       "ear=%" PRIx64 " iflags=%x\n",
153                       env->pc, msr, env->ear, env->iflags);
154 
155         /* Exception breaks branch + dslot sequence? */
156         set_esr = true;
157         env->esr &= ~D_FLAG;
158         if (env->iflags & D_FLAG) {
159             env->esr |= D_FLAG;
160             env->btr = env->btarget;
161             /* Reexecute the branch. */
162             env->regs[17] = env->pc - (env->iflags & BIMM_FLAG ? 8 : 4);
163         } else if (env->iflags & IMM_FLAG) {
164             /* Reexecute the imm. */
165             env->regs[17] = env->pc - 4;
166         } else {
167             env->regs[17] = env->pc;
168         }
169 
170         /* Exception in progress. */
171         msr |= MSR_EIP;
172         env->pc = cpu->cfg.base_vectors + 0x20;
173         break;
174 
175     case EXCP_IRQ:
176         assert(!(msr & (MSR_EIP | MSR_BIP)));
177         assert(msr & MSR_IE);
178         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
179 
180         qemu_log_mask(CPU_LOG_INT,
181                       "INT: DEV at pc=%08x msr=%08x iflags=%x\n",
182                       env->pc, msr, env->iflags);
183         set_esr = false;
184 
185         /* Disable interrupts.  */
186         msr &= ~MSR_IE;
187         env->regs[14] = env->pc;
188         env->pc = cpu->cfg.base_vectors + 0x10;
189         break;
190 
191     case EXCP_HW_BREAK:
192         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
193 
194         qemu_log_mask(CPU_LOG_INT,
195                       "INT: BRK at pc=%08x msr=%08x iflags=%x\n",
196                       env->pc, msr, env->iflags);
197         set_esr = false;
198 
199         /* Break in progress. */
200         msr |= MSR_BIP;
201         env->regs[16] = env->pc;
202         env->pc = cpu->cfg.base_vectors + 0x18;
203         break;
204 
205     default:
206         cpu_abort(cs, "unhandled exception type=%d\n", cs->exception_index);
207         /* not reached */
208     }
209 
210     /* Save previous mode, disable mmu, disable user-mode. */
211     t = (msr & (MSR_VM | MSR_UM)) << 1;
212     msr &= ~(MSR_VMS | MSR_UMS | MSR_VM | MSR_UM);
213     msr |= t;
214     mb_cpu_write_msr(env, msr);
215 
216     env->res_addr = RES_ADDR_NONE;
217     env->iflags = 0;
218 
219     if (!set_esr) {
220         qemu_log_mask(CPU_LOG_INT,
221                       "         to pc=%08x msr=%08x\n", env->pc, msr);
222     } else if (env->esr & D_FLAG) {
223         qemu_log_mask(CPU_LOG_INT,
224                       "         to pc=%08x msr=%08x esr=%04x btr=%08x\n",
225                       env->pc, msr, env->esr, env->btr);
226     } else {
227         qemu_log_mask(CPU_LOG_INT,
228                       "         to pc=%08x msr=%08x esr=%04x\n",
229                       env->pc, msr, env->esr);
230     }
231 }
232 
233 hwaddr mb_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
234 {
235     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
236     CPUMBState *env = &cpu->env;
237     target_ulong vaddr, paddr = 0;
238     MicroBlazeMMULookup lu;
239     int mmu_idx = cpu_mmu_index(env, false);
240     unsigned int hit;
241 
242     if (mmu_idx != MMU_NOMMU_IDX) {
243         hit = mmu_translate(cpu, &lu, addr, 0, 0);
244         if (hit) {
245             vaddr = addr & TARGET_PAGE_MASK;
246             paddr = lu.paddr + vaddr - lu.vaddr;
247         } else
248             paddr = 0; /* ???.  */
249     } else
250         paddr = addr & TARGET_PAGE_MASK;
251 
252     return paddr;
253 }
254 #endif
255 
256 bool mb_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
257 {
258     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
259     CPUMBState *env = &cpu->env;
260 
261     if ((interrupt_request & CPU_INTERRUPT_HARD)
262         && (env->msr & MSR_IE)
263         && !(env->msr & (MSR_EIP | MSR_BIP))
264         && !(env->iflags & (D_FLAG | IMM_FLAG))) {
265         cs->exception_index = EXCP_IRQ;
266         mb_cpu_do_interrupt(cs);
267         return true;
268     }
269     return false;
270 }
271 
272 void mb_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
273                                 MMUAccessType access_type,
274                                 int mmu_idx, uintptr_t retaddr)
275 {
276     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
277     uint32_t esr, iflags;
278 
279     /* Recover the pc and iflags from the corresponding insn_start.  */
280     cpu_restore_state(cs, retaddr, true);
281     iflags = cpu->env.iflags;
282 
283     qemu_log_mask(CPU_LOG_INT,
284                   "Unaligned access addr=" TARGET_FMT_lx " pc=%x iflags=%x\n",
285                   (target_ulong)addr, cpu->env.pc, iflags);
286 
287     esr = ESR_EC_UNALIGNED_DATA;
288     if (likely(iflags & ESR_ESS_FLAG)) {
289         esr |= iflags & ESR_ESS_MASK;
290     } else {
291         qemu_log_mask(LOG_UNIMP, "Unaligned access without ESR_ESS_FLAG\n");
292     }
293 
294     cpu->env.ear = addr;
295     cpu->env.esr = esr;
296     cs->exception_index = EXCP_HW_EXCP;
297     cpu_loop_exit(cs);
298 }
299