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 static inline uint32_t merge_syn_data_abort(uint32_t template_syn,
  14                                             unsigned int target_el,
  15                                             bool same_el, bool ea,
  16                                             bool s1ptw, bool is_write,
  17                                             int fsc)
  18 {
  19     uint32_t syn;
  20
  21     /*
  22      * ISV is only set for data aborts routed to EL2 and
  23      * never for stage-1 page table walks faulting on stage 2.
  24      *
  25      * Furthermore, ISV is only set for certain kinds of load/stores.
  26      * If the template syndrome does not have ISV set, we should leave
  27      * it cleared.
  28      *
  29      * See ARMv8 specs, D7-1974:
  30      * ISS encoding for an exception from a Data Abort, the
  31      * ISV field.
  32      */
  33     if (!(template_syn & ARM_EL_ISV) || target_el != 2 || s1ptw) {
  34         syn = syn_data_abort_no_iss(same_el, 0,
  35                                     ea, 0, s1ptw, is_write, fsc);
  36     } else {
  37         /*
  38          * Fields: IL, ISV, SAS, SSE, SRT, SF and AR come from the template
  39          * syndrome created at translation time.
  40          * Now we create the runtime syndrome with the remaining fields.
  41          */
  42         syn = syn_data_abort_with_iss(same_el,
  43                                       0, 0, 0, 0, 0,
  44                                       ea, 0, s1ptw, is_write, fsc,
  45                                       true);
  46         /* Merge the runtime syndrome with the template syndrome.  */
  47         syn |= template_syn;
  48     }
  49     return syn;
  50 }
  51
  52 static void QEMU_NORETURN arm_deliver_fault(ARMCPU *cpu, vaddr addr,
  53                                             MMUAccessType access_type,
  54                                             int mmu_idx, ARMMMUFaultInfo *fi)
  55 {
  56     CPUARMState *env = &cpu->env;
  57     int target_el;
  58     bool same_el;
  59     uint32_t syn, exc, fsr, fsc;
  60     ARMMMUIdx arm_mmu_idx = core_to_arm_mmu_idx(env, mmu_idx);
  61
  62     target_el = exception_target_el(env);
  63     if (fi->stage2) {
  64         target_el = 2;
  65         env->cp15.hpfar_el2 = extract64(fi->s2addr, 12, 47) << 4;
  66         if (arm_is_secure_below_el3(env) && fi->s1ns) {
  67             env->cp15.hpfar_el2 |= HPFAR_NS;
  68         }
  69     }
  70     same_el = (arm_current_el(env) == target_el);
  71
  72     if (target_el == 2 || arm_el_is_aa64(env, target_el) ||
  73         arm_s1_regime_using_lpae_format(env, arm_mmu_idx)) {
  74         /*
  75          * LPAE format fault status register : bottom 6 bits are
  76          * status code in the same form as needed for syndrome
  77          */
  78         fsr = arm_fi_to_lfsc(fi);
  79         fsc = extract32(fsr, 0, 6);
  80     } else {
  81         fsr = arm_fi_to_sfsc(fi);
  82         /*
  83          * Short format FSR : this fault will never actually be reported
  84          * to an EL that uses a syndrome register. Use a (currently)
  85          * reserved FSR code in case the constructed syndrome does leak
  86          * into the guest somehow.
  87          */
  88         fsc = 0x3f;
  89     }
  90
  91     if (access_type == MMU_INST_FETCH) {
  92         syn = syn_insn_abort(same_el, fi->ea, fi->s1ptw, fsc);
  93         exc = EXCP_PREFETCH_ABORT;
  94     } else {
  95         syn = merge_syn_data_abort(env->exception.syndrome, target_el,
  96                                    same_el, fi->ea, fi->s1ptw,
  97                                    access_type == MMU_DATA_STORE,
  98                                    fsc);
  99         if (access_type == MMU_DATA_STORE
 100             && arm_feature(env, ARM_FEATURE_V6)) {
 101             fsr |= (1 << 11);
 102         }
 103         exc = EXCP_DATA_ABORT;
 104     }
 105
 106     env->exception.vaddress = addr;
 107     env->exception.fsr = fsr;
 108     raise_exception(env, exc, syn, target_el);
 109 }
 110
 111 /* Raise a data fault alignment exception for the specified virtual address */
 112 void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr,
 113                                  MMUAccessType access_type,
 114                                  int mmu_idx, uintptr_t retaddr)
 115 {
 116     ARMCPU *cpu = ARM_CPU(cs);
 117     ARMMMUFaultInfo fi = {};
 118
 119     /* now we have a real cpu fault */
 120     cpu_restore_state(cs, retaddr, true);
 121
 122     fi.type = ARMFault_Alignment;
 123     arm_deliver_fault(cpu, vaddr, access_type, mmu_idx, &fi);
 124 }
 125
 126 #if !defined(CONFIG_USER_ONLY)
 127
 128 /*
 129  * arm_cpu_do_transaction_failed: handle a memory system error response
 130  * (eg "no device/memory present at address") by raising an external abort
 131  * exception
 132  */
 133 void arm_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
 134                                    vaddr addr, unsigned size,
 135                                    MMUAccessType access_type,
 136                                    int mmu_idx, MemTxAttrs attrs,
 137                                    MemTxResult response, uintptr_t retaddr)
 138 {
 139     ARMCPU *cpu = ARM_CPU(cs);
 140     ARMMMUFaultInfo fi = {};
 141
 142     /* now we have a real cpu fault */
 143     cpu_restore_state(cs, retaddr, true);
 144
 145     fi.ea = arm_extabort_type(response);
 146     fi.type = ARMFault_SyncExternal;
 147     arm_deliver_fault(cpu, addr, access_type, mmu_idx, &fi);
 148 }
 149
 150 #endif /* !defined(CONFIG_USER_ONLY) */
 151
 152 bool arm_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
 153                       MMUAccessType access_type, int mmu_idx,
 154                       bool probe, uintptr_t retaddr)
 155 {
 156     ARMCPU *cpu = ARM_CPU(cs);
 157
 158 #ifdef CONFIG_USER_ONLY
 159     cpu->env.exception.vaddress = address;
 160     if (access_type == MMU_INST_FETCH) {
 161         cs->exception_index = EXCP_PREFETCH_ABORT;
 162     } else {
 163         cs->exception_index = EXCP_DATA_ABORT;
 164     }
 165     cpu_loop_exit_restore(cs, retaddr);
 166 #else
 167     hwaddr phys_addr;
 168     target_ulong page_size;
 169     int prot, ret;
 170     MemTxAttrs attrs = {};
 171     ARMMMUFaultInfo fi = {};
 172     ARMCacheAttrs cacheattrs = {};
 173
 174     /*
 175      * Walk the page table and (if the mapping exists) add the page
 176      * to the TLB.  On success, return true.  Otherwise, if probing,
 177      * return false.  Otherwise populate fsr with ARM DFSR/IFSR fault
 178      * register format, and signal the fault.
 179      */
 180     ret = get_phys_addr(&cpu->env, address, access_type,
 181                         core_to_arm_mmu_idx(&cpu->env, mmu_idx),
 182                         &phys_addr, &attrs, &prot, &page_size,
 183                         &fi, &cacheattrs);
 184     if (likely(!ret)) {
 185         /*
 186          * Map a single [sub]page. Regions smaller than our declared
 187          * target page size are handled specially, so for those we
 188          * pass in the exact addresses.
 189          */
 190         if (page_size >= TARGET_PAGE_SIZE) {
 191             phys_addr &= TARGET_PAGE_MASK;
 192             address &= TARGET_PAGE_MASK;
 193         }
 194         /* Notice and record tagged memory. */
 195         if (cpu_isar_feature(aa64_mte, cpu) && cacheattrs.attrs == 0xf0) {
 196             arm_tlb_mte_tagged(&attrs) = true;
 197         }
 198
 199         tlb_set_page_with_attrs(cs, address, phys_addr, attrs,
 200                                 prot, mmu_idx, page_size);
 201         return true;
 202     } else if (probe) {
 203         return false;
 204     } else {
 205         /* now we have a real cpu fault */
 206         cpu_restore_state(cs, retaddr, true);
 207         arm_deliver_fault(cpu, address, access_type, mmu_idx, &fi);
 208     }
 209 #endif
 210 }