xref: /openbmc/qemu/target/microblaze/helper.c (revision e9e51b71)
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 static bool mb_cpu_access_is_secure(MicroBlazeCPU *cpu,
50                                     MMUAccessType access_type)
51 {
52     if (access_type == MMU_INST_FETCH) {
53         return !cpu->ns_axi_ip;
54     } else {
55         return !cpu->ns_axi_dp;
56     }
57 }
58 
59 bool mb_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
60                      MMUAccessType access_type, int mmu_idx,
61                      bool probe, uintptr_t retaddr)
62 {
63     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
64     CPUMBState *env = &cpu->env;
65     MicroBlazeMMULookup lu;
66     unsigned int hit;
67     int prot;
68     MemTxAttrs attrs = {};
69 
70     attrs.secure = mb_cpu_access_is_secure(cpu, access_type);
71 
72     if (mmu_idx == MMU_NOMMU_IDX) {
73         /* MMU disabled or not available.  */
74         address &= TARGET_PAGE_MASK;
75         prot = PAGE_BITS;
76         tlb_set_page_with_attrs(cs, address, address, attrs, prot, mmu_idx,
77                                 TARGET_PAGE_SIZE);
78         return true;
79     }
80 
81     hit = mmu_translate(cpu, &lu, address, access_type, mmu_idx);
82     if (likely(hit)) {
83         uint32_t vaddr = address & TARGET_PAGE_MASK;
84         uint32_t paddr = lu.paddr + vaddr - lu.vaddr;
85 
86         qemu_log_mask(CPU_LOG_MMU, "MMU map mmu=%d v=%x p=%x prot=%x\n",
87                       mmu_idx, vaddr, paddr, lu.prot);
88         tlb_set_page_with_attrs(cs, vaddr, paddr, attrs, lu.prot, mmu_idx,
89                                 TARGET_PAGE_SIZE);
90         return true;
91     }
92 
93     /* TLB miss.  */
94     if (probe) {
95         return false;
96     }
97 
98     qemu_log_mask(CPU_LOG_MMU, "mmu=%d miss v=%" VADDR_PRIx "\n",
99                   mmu_idx, address);
100 
101     env->ear = address;
102     switch (lu.err) {
103     case ERR_PROT:
104         env->esr = access_type == MMU_INST_FETCH ? 17 : 16;
105         env->esr |= (access_type == MMU_DATA_STORE) << 10;
106         break;
107     case ERR_MISS:
108         env->esr = access_type == MMU_INST_FETCH ? 19 : 18;
109         env->esr |= (access_type == MMU_DATA_STORE) << 10;
110         break;
111     default:
112         abort();
113     }
114 
115     if (cs->exception_index == EXCP_MMU) {
116         cpu_abort(cs, "recursive faults\n");
117     }
118 
119     /* TLB miss.  */
120     cs->exception_index = EXCP_MMU;
121     cpu_loop_exit_restore(cs, retaddr);
122 }
123 
124 void mb_cpu_do_interrupt(CPUState *cs)
125 {
126     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
127     CPUMBState *env = &cpu->env;
128     uint32_t t, msr = mb_cpu_read_msr(env);
129     bool set_esr;
130 
131     /* IMM flag cannot propagate across a branch and into the dslot.  */
132     assert((env->iflags & (D_FLAG | IMM_FLAG)) != (D_FLAG | IMM_FLAG));
133     /* BIMM flag cannot be set without D_FLAG. */
134     assert((env->iflags & (D_FLAG | BIMM_FLAG)) != BIMM_FLAG);
135     /* RTI flags are private to translate. */
136     assert(!(env->iflags & (DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)));
137 
138     switch (cs->exception_index) {
139     case EXCP_HW_EXCP:
140         if (!(cpu->cfg.pvr_regs[0] & PVR0_USE_EXC_MASK)) {
141             qemu_log_mask(LOG_GUEST_ERROR,
142                           "Exception raised on system without exceptions!\n");
143             return;
144         }
145 
146         qemu_log_mask(CPU_LOG_INT,
147                       "INT: HWE at pc=%08x msr=%08x iflags=%x\n",
148                       env->pc, msr, env->iflags);
149 
150         /* Exception breaks branch + dslot sequence?  */
151         set_esr = true;
152         env->esr &= ~D_FLAG;
153         if (env->iflags & D_FLAG) {
154             env->esr |= D_FLAG;
155             env->btr = env->btarget;
156         }
157 
158         /* Exception in progress. */
159         msr |= MSR_EIP;
160         env->regs[17] = env->pc + 4;
161         env->pc = cpu->cfg.base_vectors + 0x20;
162         break;
163 
164     case EXCP_MMU:
165         qemu_log_mask(CPU_LOG_INT,
166                       "INT: MMU at pc=%08x msr=%08x "
167                       "ear=%" PRIx64 " iflags=%x\n",
168                       env->pc, msr, env->ear, env->iflags);
169 
170         /* Exception breaks branch + dslot sequence? */
171         set_esr = true;
172         env->esr &= ~D_FLAG;
173         if (env->iflags & D_FLAG) {
174             env->esr |= D_FLAG;
175             env->btr = env->btarget;
176             /* Reexecute the branch. */
177             env->regs[17] = env->pc - (env->iflags & BIMM_FLAG ? 8 : 4);
178         } else if (env->iflags & IMM_FLAG) {
179             /* Reexecute the imm. */
180             env->regs[17] = env->pc - 4;
181         } else {
182             env->regs[17] = env->pc;
183         }
184 
185         /* Exception in progress. */
186         msr |= MSR_EIP;
187         env->pc = cpu->cfg.base_vectors + 0x20;
188         break;
189 
190     case EXCP_IRQ:
191         assert(!(msr & (MSR_EIP | MSR_BIP)));
192         assert(msr & MSR_IE);
193         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
194 
195         qemu_log_mask(CPU_LOG_INT,
196                       "INT: DEV at pc=%08x msr=%08x iflags=%x\n",
197                       env->pc, msr, env->iflags);
198         set_esr = false;
199 
200         /* Disable interrupts.  */
201         msr &= ~MSR_IE;
202         env->regs[14] = env->pc;
203         env->pc = cpu->cfg.base_vectors + 0x10;
204         break;
205 
206     case EXCP_HW_BREAK:
207         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
208 
209         qemu_log_mask(CPU_LOG_INT,
210                       "INT: BRK at pc=%08x msr=%08x iflags=%x\n",
211                       env->pc, msr, env->iflags);
212         set_esr = false;
213 
214         /* Break in progress. */
215         msr |= MSR_BIP;
216         env->regs[16] = env->pc;
217         env->pc = cpu->cfg.base_vectors + 0x18;
218         break;
219 
220     default:
221         cpu_abort(cs, "unhandled exception type=%d\n", cs->exception_index);
222         /* not reached */
223     }
224 
225     /* Save previous mode, disable mmu, disable user-mode. */
226     t = (msr & (MSR_VM | MSR_UM)) << 1;
227     msr &= ~(MSR_VMS | MSR_UMS | MSR_VM | MSR_UM);
228     msr |= t;
229     mb_cpu_write_msr(env, msr);
230 
231     env->res_addr = RES_ADDR_NONE;
232     env->iflags = 0;
233 
234     if (!set_esr) {
235         qemu_log_mask(CPU_LOG_INT,
236                       "         to pc=%08x msr=%08x\n", env->pc, msr);
237     } else if (env->esr & D_FLAG) {
238         qemu_log_mask(CPU_LOG_INT,
239                       "         to pc=%08x msr=%08x esr=%04x btr=%08x\n",
240                       env->pc, msr, env->esr, env->btr);
241     } else {
242         qemu_log_mask(CPU_LOG_INT,
243                       "         to pc=%08x msr=%08x esr=%04x\n",
244                       env->pc, msr, env->esr);
245     }
246 }
247 
248 hwaddr mb_cpu_get_phys_page_attrs_debug(CPUState *cs, vaddr addr,
249                                         MemTxAttrs *attrs)
250 {
251     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
252     CPUMBState *env = &cpu->env;
253     target_ulong vaddr, paddr = 0;
254     MicroBlazeMMULookup lu;
255     int mmu_idx = cpu_mmu_index(env, false);
256     unsigned int hit;
257 
258     /* Caller doesn't initialize */
259     *attrs = (MemTxAttrs) {};
260     attrs->secure = mb_cpu_access_is_secure(cpu, MMU_DATA_LOAD);
261 
262     if (mmu_idx != MMU_NOMMU_IDX) {
263         hit = mmu_translate(cpu, &lu, addr, 0, 0);
264         if (hit) {
265             vaddr = addr & TARGET_PAGE_MASK;
266             paddr = lu.paddr + vaddr - lu.vaddr;
267         } else
268             paddr = 0; /* ???.  */
269     } else
270         paddr = addr & TARGET_PAGE_MASK;
271 
272     return paddr;
273 }
274 #endif
275 
276 bool mb_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
277 {
278     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
279     CPUMBState *env = &cpu->env;
280 
281     if ((interrupt_request & CPU_INTERRUPT_HARD)
282         && (env->msr & MSR_IE)
283         && !(env->msr & (MSR_EIP | MSR_BIP))
284         && !(env->iflags & (D_FLAG | IMM_FLAG))) {
285         cs->exception_index = EXCP_IRQ;
286         mb_cpu_do_interrupt(cs);
287         return true;
288     }
289     return false;
290 }
291 
292 void mb_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
293                                 MMUAccessType access_type,
294                                 int mmu_idx, uintptr_t retaddr)
295 {
296     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
297     uint32_t esr, iflags;
298 
299     /* Recover the pc and iflags from the corresponding insn_start.  */
300     cpu_restore_state(cs, retaddr, true);
301     iflags = cpu->env.iflags;
302 
303     qemu_log_mask(CPU_LOG_INT,
304                   "Unaligned access addr=" TARGET_FMT_lx " pc=%x iflags=%x\n",
305                   (target_ulong)addr, cpu->env.pc, iflags);
306 
307     esr = ESR_EC_UNALIGNED_DATA;
308     if (likely(iflags & ESR_ESS_FLAG)) {
309         esr |= iflags & ESR_ESS_MASK;
310     } else {
311         qemu_log_mask(LOG_UNIMP, "Unaligned access without ESR_ESS_FLAG\n");
312     }
313 
314     cpu->env.ear = addr;
315     cpu->env.esr = esr;
316     cs->exception_index = EXCP_HW_EXCP;
317     cpu_loop_exit(cs);
318 }
319