xref: /openbmc/qemu/target/microblaze/helper.c (revision 9067d50d)
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 "exec/page-protection.h"
25 #include "qemu/host-utils.h"
26 #include "exec/log.h"
27 
28 #ifndef CONFIG_USER_ONLY
29 static bool mb_cpu_access_is_secure(MicroBlazeCPU *cpu,
30                                     MMUAccessType access_type)
31 {
32     if (access_type == MMU_INST_FETCH) {
33         return !cpu->ns_axi_ip;
34     } else {
35         return !cpu->ns_axi_dp;
36     }
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     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
44     CPUMBState *env = &cpu->env;
45     MicroBlazeMMULookup lu;
46     unsigned int hit;
47     int prot;
48     MemTxAttrs attrs = {};
49 
50     attrs.secure = mb_cpu_access_is_secure(cpu, access_type);
51 
52     if (mmu_idx == MMU_NOMMU_IDX) {
53         /* MMU disabled or not available.  */
54         address &= TARGET_PAGE_MASK;
55         prot = PAGE_RWX;
56         tlb_set_page_with_attrs(cs, address, address, attrs, prot, mmu_idx,
57                                 TARGET_PAGE_SIZE);
58         return true;
59     }
60 
61     hit = mmu_translate(cpu, &lu, address, access_type, mmu_idx);
62     if (likely(hit)) {
63         uint32_t vaddr = address & TARGET_PAGE_MASK;
64         uint32_t paddr = lu.paddr + vaddr - lu.vaddr;
65 
66         qemu_log_mask(CPU_LOG_MMU, "MMU map mmu=%d v=%x p=%x prot=%x\n",
67                       mmu_idx, vaddr, paddr, lu.prot);
68         tlb_set_page_with_attrs(cs, vaddr, paddr, attrs, lu.prot, mmu_idx,
69                                 TARGET_PAGE_SIZE);
70         return true;
71     }
72 
73     /* TLB miss.  */
74     if (probe) {
75         return false;
76     }
77 
78     qemu_log_mask(CPU_LOG_MMU, "mmu=%d miss v=%" VADDR_PRIx "\n",
79                   mmu_idx, address);
80 
81     env->ear = address;
82     switch (lu.err) {
83     case ERR_PROT:
84         env->esr = access_type == MMU_INST_FETCH ? 17 : 16;
85         env->esr |= (access_type == MMU_DATA_STORE) << 10;
86         break;
87     case ERR_MISS:
88         env->esr = access_type == MMU_INST_FETCH ? 19 : 18;
89         env->esr |= (access_type == MMU_DATA_STORE) << 10;
90         break;
91     default:
92         abort();
93     }
94 
95     if (cs->exception_index == EXCP_MMU) {
96         cpu_abort(cs, "recursive faults\n");
97     }
98 
99     /* TLB miss.  */
100     cs->exception_index = EXCP_MMU;
101     cpu_loop_exit_restore(cs, retaddr);
102 }
103 
104 void mb_cpu_do_interrupt(CPUState *cs)
105 {
106     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
107     CPUMBState *env = &cpu->env;
108     uint32_t t, msr = mb_cpu_read_msr(env);
109     bool set_esr;
110 
111     /* IMM flag cannot propagate across a branch and into the dslot.  */
112     assert((env->iflags & (D_FLAG | IMM_FLAG)) != (D_FLAG | IMM_FLAG));
113     /* BIMM flag cannot be set without D_FLAG. */
114     assert((env->iflags & (D_FLAG | BIMM_FLAG)) != BIMM_FLAG);
115     /* RTI flags are private to translate. */
116     assert(!(env->iflags & (DRTI_FLAG | DRTE_FLAG | DRTB_FLAG)));
117 
118     switch (cs->exception_index) {
119     case EXCP_HW_EXCP:
120         if (!(cpu->cfg.pvr_regs[0] & PVR0_USE_EXC_MASK)) {
121             qemu_log_mask(LOG_GUEST_ERROR,
122                           "Exception raised on system without exceptions!\n");
123             return;
124         }
125 
126         qemu_log_mask(CPU_LOG_INT,
127                       "INT: HWE at pc=%08x msr=%08x iflags=%x\n",
128                       env->pc, msr, env->iflags);
129 
130         /* Exception breaks branch + dslot sequence?  */
131         set_esr = true;
132         env->esr &= ~D_FLAG;
133         if (env->iflags & D_FLAG) {
134             env->esr |= D_FLAG;
135             env->btr = env->btarget;
136         }
137 
138         /* Exception in progress. */
139         msr |= MSR_EIP;
140         env->regs[17] = env->pc + 4;
141         env->pc = cpu->cfg.base_vectors + 0x20;
142         break;
143 
144     case EXCP_MMU:
145         qemu_log_mask(CPU_LOG_INT,
146                       "INT: MMU at pc=%08x msr=%08x "
147                       "ear=%" PRIx64 " iflags=%x\n",
148                       env->pc, msr, env->ear, 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             /* Reexecute the branch. */
157             env->regs[17] = env->pc - (env->iflags & BIMM_FLAG ? 8 : 4);
158         } else if (env->iflags & IMM_FLAG) {
159             /* Reexecute the imm. */
160             env->regs[17] = env->pc - 4;
161         } else {
162             env->regs[17] = env->pc;
163         }
164 
165         /* Exception in progress. */
166         msr |= MSR_EIP;
167         env->pc = cpu->cfg.base_vectors + 0x20;
168         break;
169 
170     case EXCP_IRQ:
171         assert(!(msr & (MSR_EIP | MSR_BIP)));
172         assert(msr & MSR_IE);
173         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
174 
175         qemu_log_mask(CPU_LOG_INT,
176                       "INT: DEV at pc=%08x msr=%08x iflags=%x\n",
177                       env->pc, msr, env->iflags);
178         set_esr = false;
179 
180         /* Disable interrupts.  */
181         msr &= ~MSR_IE;
182         env->regs[14] = env->pc;
183         env->pc = cpu->cfg.base_vectors + 0x10;
184         break;
185 
186     case EXCP_HW_BREAK:
187         assert(!(env->iflags & (D_FLAG | IMM_FLAG)));
188 
189         qemu_log_mask(CPU_LOG_INT,
190                       "INT: BRK at pc=%08x msr=%08x iflags=%x\n",
191                       env->pc, msr, env->iflags);
192         set_esr = false;
193 
194         /* Break in progress. */
195         msr |= MSR_BIP;
196         env->regs[16] = env->pc;
197         env->pc = cpu->cfg.base_vectors + 0x18;
198         break;
199 
200     default:
201         cpu_abort(cs, "unhandled exception type=%d\n", cs->exception_index);
202         /* not reached */
203     }
204 
205     /* Save previous mode, disable mmu, disable user-mode. */
206     t = (msr & (MSR_VM | MSR_UM)) << 1;
207     msr &= ~(MSR_VMS | MSR_UMS | MSR_VM | MSR_UM);
208     msr |= t;
209     mb_cpu_write_msr(env, msr);
210 
211     env->res_addr = RES_ADDR_NONE;
212     env->iflags = 0;
213 
214     if (!set_esr) {
215         qemu_log_mask(CPU_LOG_INT,
216                       "         to pc=%08x msr=%08x\n", env->pc, msr);
217     } else if (env->esr & D_FLAG) {
218         qemu_log_mask(CPU_LOG_INT,
219                       "         to pc=%08x msr=%08x esr=%04x btr=%08x\n",
220                       env->pc, msr, env->esr, env->btr);
221     } else {
222         qemu_log_mask(CPU_LOG_INT,
223                       "         to pc=%08x msr=%08x esr=%04x\n",
224                       env->pc, msr, env->esr);
225     }
226 }
227 
228 hwaddr mb_cpu_get_phys_page_attrs_debug(CPUState *cs, vaddr addr,
229                                         MemTxAttrs *attrs)
230 {
231     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
232     target_ulong vaddr, paddr = 0;
233     MicroBlazeMMULookup lu;
234     int mmu_idx = cpu_mmu_index(cs, false);
235     unsigned int hit;
236 
237     /* Caller doesn't initialize */
238     *attrs = (MemTxAttrs) {};
239     attrs->secure = mb_cpu_access_is_secure(cpu, MMU_DATA_LOAD);
240 
241     if (mmu_idx != MMU_NOMMU_IDX) {
242         hit = mmu_translate(cpu, &lu, addr, 0, 0);
243         if (hit) {
244             vaddr = addr & TARGET_PAGE_MASK;
245             paddr = lu.paddr + vaddr - lu.vaddr;
246         } else
247             paddr = 0; /* ???.  */
248     } else
249         paddr = addr & TARGET_PAGE_MASK;
250 
251     return paddr;
252 }
253 
254 bool mb_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
255 {
256     CPUMBState *env = cpu_env(cs);
257 
258     if ((interrupt_request & CPU_INTERRUPT_HARD)
259         && (env->msr & MSR_IE)
260         && !(env->msr & (MSR_EIP | MSR_BIP))
261         && !(env->iflags & (D_FLAG | IMM_FLAG))) {
262         cs->exception_index = EXCP_IRQ;
263         mb_cpu_do_interrupt(cs);
264         return true;
265     }
266     return false;
267 }
268 
269 #endif /* !CONFIG_USER_ONLY */
270 
271 void mb_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
272                                 MMUAccessType access_type,
273                                 int mmu_idx, uintptr_t retaddr)
274 {
275     MicroBlazeCPU *cpu = MICROBLAZE_CPU(cs);
276     uint32_t esr, iflags;
277 
278     /* Recover the pc and iflags from the corresponding insn_start.  */
279     cpu_restore_state(cs, retaddr);
280     iflags = cpu->env.iflags;
281 
282     qemu_log_mask(CPU_LOG_INT,
283                   "Unaligned access addr=" TARGET_FMT_lx " pc=%x iflags=%x\n",
284                   (target_ulong)addr, cpu->env.pc, iflags);
285 
286     esr = ESR_EC_UNALIGNED_DATA;
287     if (likely(iflags & ESR_ESS_FLAG)) {
288         esr |= iflags & ESR_ESS_MASK;
289     } else {
290         qemu_log_mask(LOG_UNIMP, "Unaligned access without ESR_ESS_FLAG\n");
291     }
292 
293     cpu->env.ear = addr;
294     cpu->env.esr = esr;
295     cs->exception_index = EXCP_HW_EXCP;
296     cpu_loop_exit(cs);
297 }
298