xref: /openbmc/qemu/target/microblaze/helper.c (revision 30e702ab)
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 bool mb_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
30                      MMUAccessType access_type, int mmu_idx,
31                      bool probe, uintptr_t retaddr)
32 {
33     cs->exception_index = 0xaa;
34     cpu_loop_exit_restore(cs, retaddr);
35 }
36 
37 #else /* !CONFIG_USER_ONLY */
38 
39 static bool mb_cpu_access_is_secure(MicroBlazeCPU *cpu,
40                                     MMUAccessType access_type)
41 {
42     if (access_type == MMU_INST_FETCH) {
43         return !cpu->ns_axi_ip;
44     } else {
45         return !cpu->ns_axi_dp;
46     }
47 }
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     MemTxAttrs attrs = {};
59 
60     attrs.secure = mb_cpu_access_is_secure(cpu, access_type);
61 
62     if (mmu_idx == MMU_NOMMU_IDX) {
63         /* MMU disabled or not available.  */
64         address &= TARGET_PAGE_MASK;
65         prot = PAGE_BITS;
66         tlb_set_page_with_attrs(cs, address, address, attrs, prot, mmu_idx,
67                                 TARGET_PAGE_SIZE);
68         return true;
69     }
70 
71     hit = mmu_translate(cpu, &lu, address, access_type, mmu_idx);
72     if (likely(hit)) {
73         uint32_t vaddr = address & TARGET_PAGE_MASK;
74         uint32_t paddr = lu.paddr + vaddr - lu.vaddr;
75 
76         qemu_log_mask(CPU_LOG_MMU, "MMU map mmu=%d v=%x p=%x prot=%x\n",
77                       mmu_idx, vaddr, paddr, lu.prot);
78         tlb_set_page_with_attrs(cs, vaddr, paddr, attrs, lu.prot, mmu_idx,
79                                 TARGET_PAGE_SIZE);
80         return true;
81     }
82 
83     /* TLB miss.  */
84     if (probe) {
85         return false;
86     }
87 
88     qemu_log_mask(CPU_LOG_MMU, "mmu=%d miss v=%" VADDR_PRIx "\n",
89                   mmu_idx, address);
90 
91     env->ear = address;
92     switch (lu.err) {
93     case ERR_PROT:
94         env->esr = access_type == MMU_INST_FETCH ? 17 : 16;
95         env->esr |= (access_type == MMU_DATA_STORE) << 10;
96         break;
97     case ERR_MISS:
98         env->esr = access_type == MMU_INST_FETCH ? 19 : 18;
99         env->esr |= (access_type == MMU_DATA_STORE) << 10;
100         break;
101     default:
102         abort();
103     }
104 
105     if (cs->exception_index == EXCP_MMU) {
106         cpu_abort(cs, "recursive faults\n");
107     }
108 
109     /* TLB miss.  */
110     cs->exception_index = EXCP_MMU;
111     cpu_loop_exit_restore(cs, retaddr);
112 }
113 
114 void mb_cpu_do_interrupt(CPUState *cs)
115 {
116     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
117     CPUMBState *env = &cpu->env;
118     uint32_t t, msr = mb_cpu_read_msr(env);
119     bool set_esr;
120 
121     /* IMM flag cannot propagate across a branch and into the dslot.  */
122     assert((env->iflags & (D_FLAG | IMM_FLAG)) != (D_FLAG | IMM_FLAG));
123     /* BIMM flag cannot be set without D_FLAG. */
124     assert((env->iflags & (D_FLAG | BIMM_FLAG)) != BIMM_FLAG);
125     /* RTI flags are private to translate. */
126     assert(!(env->iflags & (DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)));
127 
128     switch (cs->exception_index) {
129     case EXCP_HW_EXCP:
130         if (!(cpu->cfg.pvr_regs[0] & PVR0_USE_EXC_MASK)) {
131             qemu_log_mask(LOG_GUEST_ERROR,
132                           "Exception raised on system without exceptions!\n");
133             return;
134         }
135 
136         qemu_log_mask(CPU_LOG_INT,
137                       "INT: HWE at pc=%08x msr=%08x iflags=%x\n",
138                       env->pc, msr, env->iflags);
139 
140         /* Exception breaks branch + dslot sequence?  */
141         set_esr = true;
142         env->esr &= ~D_FLAG;
143         if (env->iflags & D_FLAG) {
144             env->esr |= D_FLAG;
145             env->btr = env->btarget;
146         }
147 
148         /* Exception in progress. */
149         msr |= MSR_EIP;
150         env->regs[17] = env->pc + 4;
151         env->pc = cpu->cfg.base_vectors + 0x20;
152         break;
153 
154     case EXCP_MMU:
155         qemu_log_mask(CPU_LOG_INT,
156                       "INT: MMU at pc=%08x msr=%08x "
157                       "ear=%" PRIx64 " iflags=%x\n",
158                       env->pc, msr, env->ear, env->iflags);
159 
160         /* Exception breaks branch + dslot sequence? */
161         set_esr = true;
162         env->esr &= ~D_FLAG;
163         if (env->iflags & D_FLAG) {
164             env->esr |= D_FLAG;
165             env->btr = env->btarget;
166             /* Reexecute the branch. */
167             env->regs[17] = env->pc - (env->iflags & BIMM_FLAG ? 8 : 4);
168         } else if (env->iflags & IMM_FLAG) {
169             /* Reexecute the imm. */
170             env->regs[17] = env->pc - 4;
171         } else {
172             env->regs[17] = env->pc;
173         }
174 
175         /* Exception in progress. */
176         msr |= MSR_EIP;
177         env->pc = cpu->cfg.base_vectors + 0x20;
178         break;
179 
180     case EXCP_IRQ:
181         assert(!(msr & (MSR_EIP | MSR_BIP)));
182         assert(msr & MSR_IE);
183         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
184 
185         qemu_log_mask(CPU_LOG_INT,
186                       "INT: DEV at pc=%08x msr=%08x iflags=%x\n",
187                       env->pc, msr, env->iflags);
188         set_esr = false;
189 
190         /* Disable interrupts.  */
191         msr &= ~MSR_IE;
192         env->regs[14] = env->pc;
193         env->pc = cpu->cfg.base_vectors + 0x10;
194         break;
195 
196     case EXCP_HW_BREAK:
197         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
198 
199         qemu_log_mask(CPU_LOG_INT,
200                       "INT: BRK at pc=%08x msr=%08x iflags=%x\n",
201                       env->pc, msr, env->iflags);
202         set_esr = false;
203 
204         /* Break in progress. */
205         msr |= MSR_BIP;
206         env->regs[16] = env->pc;
207         env->pc = cpu->cfg.base_vectors + 0x18;
208         break;
209 
210     default:
211         cpu_abort(cs, "unhandled exception type=%d\n", cs->exception_index);
212         /* not reached */
213     }
214 
215     /* Save previous mode, disable mmu, disable user-mode. */
216     t = (msr & (MSR_VM | MSR_UM)) << 1;
217     msr &= ~(MSR_VMS | MSR_UMS | MSR_VM | MSR_UM);
218     msr |= t;
219     mb_cpu_write_msr(env, msr);
220 
221     env->res_addr = RES_ADDR_NONE;
222     env->iflags = 0;
223 
224     if (!set_esr) {
225         qemu_log_mask(CPU_LOG_INT,
226                       "         to pc=%08x msr=%08x\n", env->pc, msr);
227     } else if (env->esr & D_FLAG) {
228         qemu_log_mask(CPU_LOG_INT,
229                       "         to pc=%08x msr=%08x esr=%04x btr=%08x\n",
230                       env->pc, msr, env->esr, env->btr);
231     } else {
232         qemu_log_mask(CPU_LOG_INT,
233                       "         to pc=%08x msr=%08x esr=%04x\n",
234                       env->pc, msr, env->esr);
235     }
236 }
237 
238 hwaddr mb_cpu_get_phys_page_attrs_debug(CPUState *cs, vaddr addr,
239                                         MemTxAttrs *attrs)
240 {
241     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
242     CPUMBState *env = &cpu->env;
243     target_ulong vaddr, paddr = 0;
244     MicroBlazeMMULookup lu;
245     int mmu_idx = cpu_mmu_index(env, false);
246     unsigned int hit;
247 
248     /* Caller doesn't initialize */
249     *attrs = (MemTxAttrs) {};
250     attrs->secure = mb_cpu_access_is_secure(cpu, MMU_DATA_LOAD);
251 
252     if (mmu_idx != MMU_NOMMU_IDX) {
253         hit = mmu_translate(cpu, &lu, addr, 0, 0);
254         if (hit) {
255             vaddr = addr & TARGET_PAGE_MASK;
256             paddr = lu.paddr + vaddr - lu.vaddr;
257         } else
258             paddr = 0; /* ???.  */
259     } else
260         paddr = addr & TARGET_PAGE_MASK;
261 
262     return paddr;
263 }
264 
265 bool mb_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
266 {
267     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
268     CPUMBState *env = &cpu->env;
269 
270     if ((interrupt_request & CPU_INTERRUPT_HARD)
271         && (env->msr & MSR_IE)
272         && !(env->msr & (MSR_EIP | MSR_BIP))
273         && !(env->iflags & (D_FLAG | IMM_FLAG))) {
274         cs->exception_index = EXCP_IRQ;
275         mb_cpu_do_interrupt(cs);
276         return true;
277     }
278     return false;
279 }
280 
281 #endif /* !CONFIG_USER_ONLY */
282 
283 void mb_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
284                                 MMUAccessType access_type,
285                                 int mmu_idx, uintptr_t retaddr)
286 {
287     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
288     uint32_t esr, iflags;
289 
290     /* Recover the pc and iflags from the corresponding insn_start.  */
291     cpu_restore_state(cs, retaddr, true);
292     iflags = cpu->env.iflags;
293 
294     qemu_log_mask(CPU_LOG_INT,
295                   "Unaligned access addr=" TARGET_FMT_lx " pc=%x iflags=%x\n",
296                   (target_ulong)addr, cpu->env.pc, iflags);
297 
298     esr = ESR_EC_UNALIGNED_DATA;
299     if (likely(iflags & ESR_ESS_FLAG)) {
300         esr |= iflags & ESR_ESS_MASK;
301     } else {
302         qemu_log_mask(LOG_UNIMP, "Unaligned access without ESR_ESS_FLAG\n");
303     }
304 
305     cpu->env.ear = addr;
306     cpu->env.esr = esr;
307     cs->exception_index = EXCP_HW_EXCP;
308     cpu_loop_exit(cs);
309 }
310