target/arm/tlb_helper.c

   1 /*
   2  * ARM TLB (Translation lookaside buffer) helpers.
   3  *
   4  * This code is licensed under the GNU GPL v2 or later.
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8 #include "qemu/osdep.h"
   9 #include "cpu.h"
  10 #include "internals.h"
  11 #include "exec/exec-all.h"
  12
  13 #if !defined(CONFIG_USER_ONLY)
  14
  15 static inline uint32_t merge_syn_data_abort(uint32_t template_syn,
  16                                             unsigned int target_el,
  17                                             bool same_el, bool ea,
  18                                             bool s1ptw, bool is_write,
  19                                             int fsc)
  20 {
  21     uint32_t syn;
  22
  23     /*
  24      * ISV is only set for data aborts routed to EL2 and
  25      * never for stage-1 page table walks faulting on stage 2.
  26      *
  27      * Furthermore, ISV is only set for certain kinds of load/stores.
  28      * If the template syndrome does not have ISV set, we should leave
  29      * it cleared.
  30      *
  31      * See ARMv8 specs, D7-1974:
  32      * ISS encoding for an exception from a Data Abort, the
  33      * ISV field.
  34      */
  35     if (!(template_syn & ARM_EL_ISV) || target_el != 2 || s1ptw) {
  36         syn = syn_data_abort_no_iss(same_el,
  37                                     ea, 0, s1ptw, is_write, fsc);
  38     } else {
  39         /*
  40          * Fields: IL, ISV, SAS, SSE, SRT, SF and AR come from the template
  41          * syndrome created at translation time.
  42          * Now we create the runtime syndrome with the remaining fields.
  43          */
  44         syn = syn_data_abort_with_iss(same_el,
  45                                       0, 0, 0, 0, 0,
  46                                       ea, 0, s1ptw, is_write, fsc,
  47                                       true);
  48         /* Merge the runtime syndrome with the template syndrome.  */
  49         syn |= template_syn;
  50     }
  51     return syn;
  52 }
  53
  54 static void QEMU_NORETURN arm_deliver_fault(ARMCPU *cpu, vaddr addr,
  55                                             MMUAccessType access_type,
  56                                             int mmu_idx, ARMMMUFaultInfo *fi)
  57 {
  58     CPUARMState *env = &cpu->env;
  59     int target_el;
  60     bool same_el;
  61     uint32_t syn, exc, fsr, fsc;
  62     ARMMMUIdx arm_mmu_idx = core_to_arm_mmu_idx(env, mmu_idx);
  63
  64     target_el = exception_target_el(env);
  65     if (fi->stage2) {
  66         target_el = 2;
  67         env->cp15.hpfar_el2 = extract64(fi->s2addr, 12, 47) << 4;
  68     }
  69     same_el = (arm_current_el(env) == target_el);
  70
  71     if (target_el == 2 || arm_el_is_aa64(env, target_el) ||
  72         arm_s1_regime_using_lpae_format(env, arm_mmu_idx)) {
  73         /*
  74          * LPAE format fault status register : bottom 6 bits are
  75          * status code in the same form as needed for syndrome
  76          */
  77         fsr = arm_fi_to_lfsc(fi);
  78         fsc = extract32(fsr, 0, 6);
  79     } else {
  80         fsr = arm_fi_to_sfsc(fi);
  81         /*
  82          * Short format FSR : this fault will never actually be reported
  83          * to an EL that uses a syndrome register. Use a (currently)
  84          * reserved FSR code in case the constructed syndrome does leak
  85          * into the guest somehow.
  86          */
  87         fsc = 0x3f;
  88     }
  89
  90     if (access_type == MMU_INST_FETCH) {
  91         syn = syn_insn_abort(same_el, fi->ea, fi->s1ptw, fsc);
  92         exc = EXCP_PREFETCH_ABORT;
  93     } else {
  94         syn = merge_syn_data_abort(env->exception.syndrome, target_el,
  95                                    same_el, fi->ea, fi->s1ptw,
  96                                    access_type == MMU_DATA_STORE,
  97                                    fsc);
  98         if (access_type == MMU_DATA_STORE
  99             && arm_feature(env, ARM_FEATURE_V6)) {
 100             fsr |= (1 << 11);
 101         }
 102         exc = EXCP_DATA_ABORT;
 103     }
 104
 105     env->exception.vaddress = addr;
 106     env->exception.fsr = fsr;
 107     raise_exception(env, exc, syn, target_el);
 108 }
 109
 110 /* Raise a data fault alignment exception for the specified virtual address */
 111 void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
 112                                  MMUAccessType access_type,
 113                                  int mmu_idx, uintptr_t retaddr)
 114 {
 115     ARMCPU *cpu = ARM_CPU(cs);
 116     ARMMMUFaultInfo fi = {};
 117
 118     /* now we have a real cpu fault */
 119     cpu_restore_state(cs, retaddr, true);
 120
 121     fi.type = ARMFault_Alignment;
 122     arm_deliver_fault(cpu, vaddr, access_type, mmu_idx, &fi);
 123 }
 124
 125 /*
 126  * arm_cpu_do_transaction_failed: handle a memory system error response
 127  * (eg "no device/memory present at address") by raising an external abort
 128  * exception
 129  */
 130 void arm_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
 131                                    vaddr addr, unsigned size,
 132                                    MMUAccessType access_type,
 133                                    int mmu_idx, MemTxAttrs attrs,
 134                                    MemTxResult response, uintptr_t retaddr)
 135 {
 136     ARMCPU *cpu = ARM_CPU(cs);
 137     ARMMMUFaultInfo fi = {};
 138
 139     /* now we have a real cpu fault */
 140     cpu_restore_state(cs, retaddr, true);
 141
 142     fi.ea = arm_extabort_type(response);
 143     fi.type = ARMFault_SyncExternal;
 144     arm_deliver_fault(cpu, addr, access_type, mmu_idx, &fi);
 145 }
 146
 147 #endif /* !defined(CONFIG_USER_ONLY) */
 148
 149 bool arm_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
 150                       MMUAccessType access_type, int mmu_idx,
 151                       bool probe, uintptr_t retaddr)
 152 {
 153     ARMCPU *cpu = ARM_CPU(cs);
 154
 155 #ifdef CONFIG_USER_ONLY
 156     cpu->env.exception.vaddress = address;
 157     if (access_type == MMU_INST_FETCH) {
 158         cs->exception_index = EXCP_PREFETCH_ABORT;
 159     } else {
 160         cs->exception_index = EXCP_DATA_ABORT;
 161     }
 162     cpu_loop_exit_restore(cs, retaddr);
 163 #else
 164     hwaddr phys_addr;
 165     target_ulong page_size;
 166     int prot, ret;
 167     MemTxAttrs attrs = {};
 168     ARMMMUFaultInfo fi = {};
 169
 170     /*
 171      * Walk the page table and (if the mapping exists) add the page
 172      * to the TLB.  On success, return true.  Otherwise, if probing,
 173      * return false.  Otherwise populate fsr with ARM DFSR/IFSR fault
 174      * register format, and signal the fault.
 175      */
 176     ret = get_phys_addr(&cpu->env, address, access_type,
 177                         core_to_arm_mmu_idx(&cpu->env, mmu_idx),
 178                         &phys_addr, &attrs, &prot, &page_size, &fi, NULL);
 179     if (likely(!ret)) {
 180         /*
 181          * Map a single [sub]page. Regions smaller than our declared
 182          * target page size are handled specially, so for those we
 183          * pass in the exact addresses.
 184          */
 185         if (page_size >= TARGET_PAGE_SIZE) {
 186             phys_addr &= TARGET_PAGE_MASK;
 187             address &= TARGET_PAGE_MASK;
 188         }
 189         tlb_set_page_with_attrs(cs, address, phys_addr, attrs,
 190                                 prot, mmu_idx, page_size);
 191         return true;
 192     } else if (probe) {
 193         return false;
 194     } else {
 195         /* now we have a real cpu fault */
 196         cpu_restore_state(cs, retaddr, true);
 197         arm_deliver_fault(cpu, address, access_type, mmu_idx, &fi);
 198     }
 199 #endif
 200 }