xref: /qemu/target/microblaze/helper.c (revision 67f2d507ca444cfff993c1a05df3aaa4346a372c)
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/cputlb.h"
24 #include "accel/tcg/cpu-mmu-index.h"
25 #include "exec/page-protection.h"
26 #include "exec/target_page.h"
27 #include "qemu/host-utils.h"
28 #include "exec/log.h"
29 
30 
31 G_NORETURN
32 static void mb_unaligned_access_internal(CPUState *cs, uint64_t addr,
33                                          uintptr_t retaddr)
34 {
35     CPUMBState *env = cpu_env(cs);
36     uint32_t esr, iflags;
37 
38     /* Recover the pc and iflags from the corresponding insn_start.  */
39     cpu_restore_state(cs, retaddr);
40     iflags = env->iflags;
41 
42     qemu_log_mask(CPU_LOG_INT,
43                   "Unaligned access addr=0x%" PRIx64 " pc=%x iflags=%x\n",
44                   addr, env->pc, iflags);
45 
46     esr = ESR_EC_UNALIGNED_DATA;
47     if (likely(iflags & ESR_ESS_FLAG)) {
48         esr |= iflags & ESR_ESS_MASK;
49     } else {
50         qemu_log_mask(LOG_UNIMP, "Unaligned access without ESR_ESS_FLAG\n");
51     }
52 
53     env->ear = addr;
54     env->esr = esr;
55     cs->exception_index = EXCP_HW_EXCP;
56     cpu_loop_exit(cs);
57 }
58 
59 void mb_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
60                                 MMUAccessType access_type,
61                                 int mmu_idx, uintptr_t retaddr)
62 {
63     mb_unaligned_access_internal(cs, addr, retaddr);
64 }
65 
66 #ifndef CONFIG_USER_ONLY
67 static bool mb_cpu_access_is_secure(MicroBlazeCPU *cpu,
68                                     MMUAccessType access_type)
69 {
70     if (access_type == MMU_INST_FETCH) {
71         return !cpu->ns_axi_ip;
72     } else {
73         return !cpu->ns_axi_dp;
74     }
75 }
76 
77 bool mb_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
78                      MMUAccessType access_type, int mmu_idx,
79                      bool probe, uintptr_t retaddr)
80 {
81     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
82     CPUMBState *env = &cpu->env;
83     MicroBlazeMMULookup lu;
84     unsigned int hit;
85     int prot;
86     MemTxAttrs attrs = {};
87 
88     attrs.secure = mb_cpu_access_is_secure(cpu, access_type);
89 
90     if (mmu_idx == MMU_NOMMU_IDX) {
91         /* MMU disabled or not available.  */
92         address &= TARGET_PAGE_MASK;
93         prot = PAGE_RWX;
94         tlb_set_page_with_attrs(cs, address, address, attrs, prot, mmu_idx,
95                                 TARGET_PAGE_SIZE);
96         return true;
97     }
98 
99     hit = mmu_translate(cpu, &lu, address, access_type, mmu_idx);
100     if (likely(hit)) {
101         uint32_t vaddr = address & TARGET_PAGE_MASK;
102         uint32_t paddr = lu.paddr + vaddr - lu.vaddr;
103 
104         qemu_log_mask(CPU_LOG_MMU, "MMU map mmu=%d v=%x p=%x prot=%x\n",
105                       mmu_idx, vaddr, paddr, lu.prot);
106         tlb_set_page_with_attrs(cs, vaddr, paddr, attrs, lu.prot, mmu_idx,
107                                 TARGET_PAGE_SIZE);
108         return true;
109     }
110 
111     /* TLB miss.  */
112     if (probe) {
113         return false;
114     }
115 
116     qemu_log_mask(CPU_LOG_MMU, "mmu=%d miss v=%" VADDR_PRIx "\n",
117                   mmu_idx, address);
118 
119     env->ear = address;
120     switch (lu.err) {
121     case ERR_PROT:
122         env->esr = access_type == MMU_INST_FETCH ? 17 : 16;
123         env->esr |= (access_type == MMU_DATA_STORE) << 10;
124         break;
125     case ERR_MISS:
126         env->esr = access_type == MMU_INST_FETCH ? 19 : 18;
127         env->esr |= (access_type == MMU_DATA_STORE) << 10;
128         break;
129     default:
130         abort();
131     }
132 
133     if (cs->exception_index == EXCP_MMU) {
134         cpu_abort(cs, "recursive faults\n");
135     }
136 
137     /* TLB miss.  */
138     cs->exception_index = EXCP_MMU;
139     cpu_loop_exit_restore(cs, retaddr);
140 }
141 
142 void mb_cpu_do_interrupt(CPUState *cs)
143 {
144     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
145     CPUMBState *env = &cpu->env;
146     uint32_t t, msr = mb_cpu_read_msr(env);
147     bool set_esr;
148 
149     /* IMM flag cannot propagate across a branch and into the dslot.  */
150     assert((env->iflags & (D_FLAG | IMM_FLAG)) != (D_FLAG | IMM_FLAG));
151     /* BIMM flag cannot be set without D_FLAG. */
152     assert((env->iflags & (D_FLAG | BIMM_FLAG)) != BIMM_FLAG);
153     /* RTI flags are private to translate. */
154     assert(!(env->iflags & (DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)));
155 
156     switch (cs->exception_index) {
157     case EXCP_HW_EXCP:
158         if (!(cpu->cfg.pvr_regs[0] & PVR0_USE_EXC_MASK)) {
159             qemu_log_mask(LOG_GUEST_ERROR,
160                           "Exception raised on system without exceptions!\n");
161             return;
162         }
163 
164         qemu_log_mask(CPU_LOG_INT,
165                       "INT: HWE at pc=%08x msr=%08x iflags=%x\n",
166                       env->pc, msr, env->iflags);
167 
168         /* Exception breaks branch + dslot sequence?  */
169         set_esr = true;
170         env->esr &= ~D_FLAG;
171         if (env->iflags & D_FLAG) {
172             env->esr |= D_FLAG;
173             env->btr = env->btarget;
174         }
175 
176         /* Exception in progress. */
177         msr |= MSR_EIP;
178         env->regs[17] = env->pc + 4;
179         env->pc = cpu->cfg.base_vectors + 0x20;
180         break;
181 
182     case EXCP_MMU:
183         qemu_log_mask(CPU_LOG_INT,
184                       "INT: MMU at pc=%08x msr=%08x "
185                       "ear=%" PRIx64 " iflags=%x\n",
186                       env->pc, msr, env->ear, env->iflags);
187 
188         /* Exception breaks branch + dslot sequence? */
189         set_esr = true;
190         env->esr &= ~D_FLAG;
191         if (env->iflags & D_FLAG) {
192             env->esr |= D_FLAG;
193             env->btr = env->btarget;
194             /* Reexecute the branch. */
195             env->regs[17] = env->pc - (env->iflags & BIMM_FLAG ? 8 : 4);
196         } else if (env->iflags & IMM_FLAG) {
197             /* Reexecute the imm. */
198             env->regs[17] = env->pc - 4;
199         } else {
200             env->regs[17] = env->pc;
201         }
202 
203         /* Exception in progress. */
204         msr |= MSR_EIP;
205         env->pc = cpu->cfg.base_vectors + 0x20;
206         break;
207 
208     case EXCP_IRQ:
209         assert(!(msr & (MSR_EIP | MSR_BIP)));
210         assert(msr & MSR_IE);
211         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
212 
213         qemu_log_mask(CPU_LOG_INT,
214                       "INT: DEV at pc=%08x msr=%08x iflags=%x\n",
215                       env->pc, msr, env->iflags);
216         set_esr = false;
217 
218         /* Disable interrupts.  */
219         msr &= ~MSR_IE;
220         env->regs[14] = env->pc;
221         env->pc = cpu->cfg.base_vectors + 0x10;
222         break;
223 
224     case EXCP_HW_BREAK:
225         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
226 
227         qemu_log_mask(CPU_LOG_INT,
228                       "INT: BRK at pc=%08x msr=%08x iflags=%x\n",
229                       env->pc, msr, env->iflags);
230         set_esr = false;
231 
232         /* Break in progress. */
233         msr |= MSR_BIP;
234         env->regs[16] = env->pc;
235         env->pc = cpu->cfg.base_vectors + 0x18;
236         break;
237 
238     default:
239         cpu_abort(cs, "unhandled exception type=%d\n", cs->exception_index);
240         /* not reached */
241     }
242 
243     /* Save previous mode, disable mmu, disable user-mode. */
244     t = (msr & (MSR_VM | MSR_UM)) << 1;
245     msr &= ~(MSR_VMS | MSR_UMS | MSR_VM | MSR_UM);
246     msr |= t;
247     mb_cpu_write_msr(env, msr);
248 
249     env->res_addr = RES_ADDR_NONE;
250     env->iflags = 0;
251 
252     if (!set_esr) {
253         qemu_log_mask(CPU_LOG_INT,
254                       "         to pc=%08x msr=%08x\n", env->pc, msr);
255     } else if (env->esr & D_FLAG) {
256         qemu_log_mask(CPU_LOG_INT,
257                       "         to pc=%08x msr=%08x esr=%04x btr=%08x\n",
258                       env->pc, msr, env->esr, env->btr);
259     } else {
260         qemu_log_mask(CPU_LOG_INT,
261                       "         to pc=%08x msr=%08x esr=%04x\n",
262                       env->pc, msr, env->esr);
263     }
264 }
265 
266 hwaddr mb_cpu_get_phys_page_attrs_debug(CPUState *cs, vaddr addr,
267                                         MemTxAttrs *attrs)
268 {
269     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
270     target_ulong vaddr, paddr = 0;
271     MicroBlazeMMULookup lu;
272     int mmu_idx = cpu_mmu_index(cs, false);
273     unsigned int hit;
274 
275     /* Caller doesn't initialize */
276     *attrs = (MemTxAttrs) {};
277     attrs->secure = mb_cpu_access_is_secure(cpu, MMU_DATA_LOAD);
278 
279     if (mmu_idx != MMU_NOMMU_IDX) {
280         hit = mmu_translate(cpu, &lu, addr, 0, 0);
281         if (hit) {
282             vaddr = addr & TARGET_PAGE_MASK;
283             paddr = lu.paddr + vaddr - lu.vaddr;
284         } else
285             paddr = 0; /* ???.  */
286     } else
287         paddr = addr & TARGET_PAGE_MASK;
288 
289     return paddr;
290 }
291 
292 bool mb_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
293 {
294     CPUMBState *env = cpu_env(cs);
295 
296     if ((interrupt_request & CPU_INTERRUPT_HARD)
297         && (env->msr & MSR_IE)
298         && !(env->msr & (MSR_EIP | MSR_BIP))
299         && !(env->iflags & (D_FLAG | IMM_FLAG))) {
300         cs->exception_index = EXCP_IRQ;
301         mb_cpu_do_interrupt(cs);
302         return true;
303     }
304     return false;
305 }
306 
307 #endif /* !CONFIG_USER_ONLY */
308