target-openrisc/mmu.c

   1 /*
   2  * OpenRISC MMU.
   3  *
   4  * Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
   5  *                         Zhizhou Zhang <etouzh@gmail.com>
   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 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 "qemu-common.h"
  24 #include "exec/gdbstub.h"
  25 #include "qemu/host-utils.h"
  26 #ifndef CONFIG_USER_ONLY
  27 #include "hw/loader.h"
  28 #endif
  29
  30 #ifndef CONFIG_USER_ONLY
  31 int cpu_openrisc_get_phys_nommu(OpenRISCCPU *cpu,
  32                                 hwaddr *physical,
  33                                 int *prot, target_ulong address, int rw)
  34 {
  35     *physical = address;
  36     *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
  37     return TLBRET_MATCH;
  38 }
  39
  40 int cpu_openrisc_get_phys_code(OpenRISCCPU *cpu,
  41                                hwaddr *physical,
  42                                int *prot, target_ulong address, int rw)
  43 {
  44     int vpn = address >> TARGET_PAGE_BITS;
  45     int idx = vpn & ITLB_MASK;
  46     int right = 0;
  47
  48     if ((cpu->env.tlb->itlb[0][idx].mr >> TARGET_PAGE_BITS) != vpn) {
  49         return TLBRET_NOMATCH;
  50     }
  51     if (!(cpu->env.tlb->itlb[0][idx].mr & 1)) {
  52         return TLBRET_INVALID;
  53     }
  54
  55     if (cpu->env.sr & SR_SM) { /* supervisor mode */
  56         if (cpu->env.tlb->itlb[0][idx].tr & SXE) {
  57             right |= PAGE_EXEC;
  58         }
  59     } else {
  60         if (cpu->env.tlb->itlb[0][idx].tr & UXE) {
  61             right |= PAGE_EXEC;
  62         }
  63     }
  64
  65     if ((rw & 2) && ((right & PAGE_EXEC) == 0)) {
  66         return TLBRET_BADADDR;
  67     }
  68
  69     *physical = (cpu->env.tlb->itlb[0][idx].tr & TARGET_PAGE_MASK) |
  70                 (address & (TARGET_PAGE_SIZE-1));
  71     *prot = right;
  72     return TLBRET_MATCH;
  73 }
  74
  75 int cpu_openrisc_get_phys_data(OpenRISCCPU *cpu,
  76                                hwaddr *physical,
  77                                int *prot, target_ulong address, int rw)
  78 {
  79     int vpn = address >> TARGET_PAGE_BITS;
  80     int idx = vpn & DTLB_MASK;
  81     int right = 0;
  82
  83     if ((cpu->env.tlb->dtlb[0][idx].mr >> TARGET_PAGE_BITS) != vpn) {
  84         return TLBRET_NOMATCH;
  85     }
  86     if (!(cpu->env.tlb->dtlb[0][idx].mr & 1)) {
  87         return TLBRET_INVALID;
  88     }
  89
  90     if (cpu->env.sr & SR_SM) { /* supervisor mode */
  91         if (cpu->env.tlb->dtlb[0][idx].tr & SRE) {
  92             right |= PAGE_READ;
  93         }
  94         if (cpu->env.tlb->dtlb[0][idx].tr & SWE) {
  95             right |= PAGE_WRITE;
  96         }
  97     } else {
  98         if (cpu->env.tlb->dtlb[0][idx].tr & URE) {
  99             right |= PAGE_READ;
 100         }
 101         if (cpu->env.tlb->dtlb[0][idx].tr & UWE) {
 102             right |= PAGE_WRITE;
 103         }
 104     }
 105
 106     if (!(rw & 1) && ((right & PAGE_READ) == 0)) {
 107         return TLBRET_BADADDR;
 108     }
 109     if ((rw & 1) && ((right & PAGE_WRITE) == 0)) {
 110         return TLBRET_BADADDR;
 111     }
 112
 113     *physical = (cpu->env.tlb->dtlb[0][idx].tr & TARGET_PAGE_MASK) |
 114                 (address & (TARGET_PAGE_SIZE-1));
 115     *prot = right;
 116     return TLBRET_MATCH;
 117 }
 118
 119 static int cpu_openrisc_get_phys_addr(OpenRISCCPU *cpu,
 120                                       hwaddr *physical,
 121                                       int *prot, target_ulong address,
 122                                       int rw)
 123 {
 124     int ret = TLBRET_MATCH;
 125
 126     if (rw == 2) {    /* ITLB */
 127        *physical = 0;
 128         ret = cpu->env.tlb->cpu_openrisc_map_address_code(cpu, physical,
 129                                                           prot, address, rw);
 130     } else {          /* DTLB */
 131         ret = cpu->env.tlb->cpu_openrisc_map_address_data(cpu, physical,
 132                                                           prot, address, rw);
 133     }
 134
 135     return ret;
 136 }
 137 #endif
 138
 139 static void cpu_openrisc_raise_mmu_exception(OpenRISCCPU *cpu,
 140                                              target_ulong address,
 141                                              int rw, int tlb_error)
 142 {
 143     CPUState *cs = CPU(cpu);
 144     int exception = 0;
 145
 146     switch (tlb_error) {
 147     default:
 148         if (rw == 2) {
 149             exception = EXCP_IPF;
 150         } else {
 151             exception = EXCP_DPF;
 152         }
 153         break;
 154 #ifndef CONFIG_USER_ONLY
 155     case TLBRET_BADADDR:
 156         if (rw == 2) {
 157             exception = EXCP_IPF;
 158         } else {
 159             exception = EXCP_DPF;
 160         }
 161         break;
 162     case TLBRET_INVALID:
 163     case TLBRET_NOMATCH:
 164         /* No TLB match for a mapped address */
 165         if (rw == 2) {
 166             exception = EXCP_ITLBMISS;
 167         } else {
 168             exception = EXCP_DTLBMISS;
 169         }
 170         break;
 171 #endif
 172     }
 173
 174     cs->exception_index = exception;
 175     cpu->env.eear = address;
 176 }
 177
 178 #ifndef CONFIG_USER_ONLY
 179 int openrisc_cpu_handle_mmu_fault(CPUState *cs,
 180                                   vaddr address, int rw, int mmu_idx)
 181 {
 182     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
 183     int ret = 0;
 184     hwaddr physical = 0;
 185     int prot = 0;
 186
 187     ret = cpu_openrisc_get_phys_addr(cpu, &physical, &prot,
 188                                      address, rw);
 189
 190     if (ret == TLBRET_MATCH) {
 191         tlb_set_page(cs, address & TARGET_PAGE_MASK,
 192                      physical & TARGET_PAGE_MASK, prot,
 193                      mmu_idx, TARGET_PAGE_SIZE);
 194         ret = 0;
 195     } else if (ret < 0) {
 196         cpu_openrisc_raise_mmu_exception(cpu, address, rw, ret);
 197         ret = 1;
 198     }
 199
 200     return ret;
 201 }
 202 #else
 203 int openrisc_cpu_handle_mmu_fault(CPUState *cs,
 204                                   vaddr address, int rw, int mmu_idx)
 205 {
 206     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
 207     int ret = 0;
 208
 209     cpu_openrisc_raise_mmu_exception(cpu, address, rw, ret);
 210     ret = 1;
 211
 212     return ret;
 213 }
 214 #endif
 215
 216 #ifndef CONFIG_USER_ONLY
 217 hwaddr openrisc_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
 218 {
 219     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
 220     hwaddr phys_addr;
 221     int prot;
 222
 223     if (cpu_openrisc_get_phys_addr(cpu, &phys_addr, &prot, addr, 0)) {
 224         return -1;
 225     }
 226
 227     return phys_addr;
 228 }
 229
 230 void cpu_openrisc_mmu_init(OpenRISCCPU *cpu)
 231 {
 232     cpu->env.tlb = g_malloc0(sizeof(CPUOpenRISCTLBContext));
 233
 234     cpu->env.tlb->cpu_openrisc_map_address_code = &cpu_openrisc_get_phys_nommu;
 235     cpu->env.tlb->cpu_openrisc_map_address_data = &cpu_openrisc_get_phys_nommu;
 236 }
 237 #endif