diff options
Diffstat (limited to 'target/arm/tcg/tlb_helper.c')
| -rw-r--r-- | target/arm/tcg/tlb_helper.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/target/arm/tcg/tlb_helper.c b/target/arm/tcg/tlb_helper.c new file mode 100644 index 0000000000..60abcbebe6 --- /dev/null +++ b/target/arm/tcg/tlb_helper.c @@ -0,0 +1,287 @@ +/* + * ARM TLB (Translation lookaside buffer) helpers. + * + * This code is licensed under the GNU GPL v2 or later. + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ +#include "qemu/osdep.h" +#include "cpu.h" +#include "internals.h" +#include "exec/exec-all.h" +#include "exec/helper-proto.h" + + +/* Return true if the translation regime is using LPAE format page tables */ +bool regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx) +{ + int el = regime_el(env, mmu_idx); + if (el == 2 || arm_el_is_aa64(env, el)) { + return true; + } + if (arm_feature(env, ARM_FEATURE_PMSA) && + arm_feature(env, ARM_FEATURE_V8)) { + return true; + } + if (arm_feature(env, ARM_FEATURE_LPAE) + && (regime_tcr(env, mmu_idx) & TTBCR_EAE)) { + return true; + } + return false; +} + +/* + * Returns true if the stage 1 translation regime is using LPAE format page + * tables. Used when raising alignment exceptions, whose FSR changes depending + * on whether the long or short descriptor format is in use. + */ +bool arm_s1_regime_using_lpae_format(CPUARMState *env, ARMMMUIdx mmu_idx) +{ + mmu_idx = stage_1_mmu_idx(mmu_idx); + return regime_using_lpae_format(env, mmu_idx); +} + +static inline uint32_t merge_syn_data_abort(uint32_t template_syn, + unsigned int target_el, + bool same_el, bool ea, + bool s1ptw, bool is_write, + int fsc) +{ + uint32_t syn; + + /* + * ISV is only set for data aborts routed to EL2 and + * never for stage-1 page table walks faulting on stage 2. + * + * Furthermore, ISV is only set for certain kinds of load/stores. + * If the template syndrome does not have ISV set, we should leave + * it cleared. + * + * See ARMv8 specs, D7-1974: + * ISS encoding for an exception from a Data Abort, the + * ISV field. + */ + if (!(template_syn & ARM_EL_ISV) || target_el != 2 || s1ptw) { + syn = syn_data_abort_no_iss(same_el, 0, + ea, 0, s1ptw, is_write, fsc); + } else { + /* + * Fields: IL, ISV, SAS, SSE, SRT, SF and AR come from the template + * syndrome created at translation time. + * Now we create the runtime syndrome with the remaining fields. + */ + syn = syn_data_abort_with_iss(same_el, + 0, 0, 0, 0, 0, + ea, 0, s1ptw, is_write, fsc, + true); + /* Merge the runtime syndrome with the template syndrome. */ + syn |= template_syn; + } + return syn; +} + +static uint32_t compute_fsr_fsc(CPUARMState *env, ARMMMUFaultInfo *fi, + int target_el, int mmu_idx, uint32_t *ret_fsc) +{ + ARMMMUIdx arm_mmu_idx = core_to_arm_mmu_idx(env, mmu_idx); + uint32_t fsr, fsc; + + if (target_el == 2 || arm_el_is_aa64(env, target_el) || + arm_s1_regime_using_lpae_format(env, arm_mmu_idx)) { + /* + * LPAE format fault status register : bottom 6 bits are + * status code in the same form as needed for syndrome + */ + fsr = arm_fi_to_lfsc(fi); + fsc = extract32(fsr, 0, 6); + } else { + fsr = arm_fi_to_sfsc(fi); + /* + * Short format FSR : this fault will never actually be reported + * to an EL that uses a syndrome register. Use a (currently) + * reserved FSR code in case the constructed syndrome does leak + * into the guest somehow. + */ + fsc = 0x3f; + } + + *ret_fsc = fsc; + return fsr; +} + +static G_NORETURN +void arm_deliver_fault(ARMCPU *cpu, vaddr addr, + MMUAccessType access_type, + int mmu_idx, ARMMMUFaultInfo *fi) +{ + CPUARMState *env = &cpu->env; + int target_el; + bool same_el; + uint32_t syn, exc, fsr, fsc; + + target_el = exception_target_el(env); + if (fi->stage2) { + target_el = 2; + env->cp15.hpfar_el2 = extract64(fi->s2addr, 12, 47) << 4; + if (arm_is_secure_below_el3(env) && fi->s1ns) { + env->cp15.hpfar_el2 |= HPFAR_NS; + } + } + same_el = (arm_current_el(env) == target_el); + + fsr = compute_fsr_fsc(env, fi, target_el, mmu_idx, &fsc); + + if (access_type == MMU_INST_FETCH) { + syn = syn_insn_abort(same_el, fi->ea, fi->s1ptw, fsc); + exc = EXCP_PREFETCH_ABORT; + } else { + syn = merge_syn_data_abort(env->exception.syndrome, target_el, + same_el, fi->ea, fi->s1ptw, + access_type == MMU_DATA_STORE, + fsc); + if (access_type == MMU_DATA_STORE + && arm_feature(env, ARM_FEATURE_V6)) { + fsr |= (1 << 11); + } + exc = EXCP_DATA_ABORT; + } + + env->exception.vaddress = addr; + env->exception.fsr = fsr; + raise_exception(env, exc, syn, target_el); +} + +/* Raise a data fault alignment exception for the specified virtual address */ +void arm_cpu_do_unaligned_access(CPUState *cs, vaddr vaddr, + MMUAccessType access_type, + int mmu_idx, uintptr_t retaddr) +{ + ARMCPU *cpu = ARM_CPU(cs); + ARMMMUFaultInfo fi = {}; + + /* now we have a real cpu fault */ + cpu_restore_state(cs, retaddr); + + fi.type = ARMFault_Alignment; + arm_deliver_fault(cpu, vaddr, access_type, mmu_idx, &fi); +} + +void helper_exception_pc_alignment(CPUARMState *env, target_ulong pc) +{ + ARMMMUFaultInfo fi = { .type = ARMFault_Alignment }; + int target_el = exception_target_el(env); + int mmu_idx = cpu_mmu_index(env, true); + uint32_t fsc; + + env->exception.vaddress = pc; + + /* + * Note that the fsc is not applicable to this exception, + * since any syndrome is pcalignment not insn_abort. + */ + env->exception.fsr = compute_fsr_fsc(env, &fi, target_el, mmu_idx, &fsc); + raise_exception(env, EXCP_PREFETCH_ABORT, syn_pcalignment(), target_el); +} + +#if !defined(CONFIG_USER_ONLY) + +/* + * arm_cpu_do_transaction_failed: handle a memory system error response + * (eg "no device/memory present at address") by raising an external abort + * exception + */ +void arm_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr, + vaddr addr, unsigned size, + MMUAccessType access_type, + int mmu_idx, MemTxAttrs attrs, + MemTxResult response, uintptr_t retaddr) +{ + ARMCPU *cpu = ARM_CPU(cs); + ARMMMUFaultInfo fi = {}; + + /* now we have a real cpu fault */ + cpu_restore_state(cs, retaddr); + + fi.ea = arm_extabort_type(response); + fi.type = ARMFault_SyncExternal; + arm_deliver_fault(cpu, addr, access_type, mmu_idx, &fi); +} + +bool arm_cpu_tlb_fill(CPUState *cs, vaddr address, int size, + MMUAccessType access_type, int mmu_idx, + bool probe, uintptr_t retaddr) +{ + ARMCPU *cpu = ARM_CPU(cs); + GetPhysAddrResult res = {}; + ARMMMUFaultInfo local_fi, *fi; + int ret; + + /* + * Allow S1_ptw_translate to see any fault generated here. + * Since this may recurse, read and clear. + */ + fi = cpu->env.tlb_fi; + if (fi) { + cpu->env.tlb_fi = NULL; + } else { + fi = memset(&local_fi, 0, sizeof(local_fi)); + } + + /* + * Walk the page table and (if the mapping exists) add the page + * to the TLB. On success, return true. Otherwise, if probing, + * return false. Otherwise populate fsr with ARM DFSR/IFSR fault + * register format, and signal the fault. + */ + ret = get_phys_addr(&cpu->env, address, access_type, + core_to_arm_mmu_idx(&cpu->env, mmu_idx), + &res, fi); + if (likely(!ret)) { + /* + * Map a single [sub]page. Regions smaller than our declared + * target page size are handled specially, so for those we + * pass in the exact addresses. + */ + if (res.f.lg_page_size >= TARGET_PAGE_BITS) { + res.f.phys_addr &= TARGET_PAGE_MASK; + address &= TARGET_PAGE_MASK; + } + + res.f.pte_attrs = res.cacheattrs.attrs; + res.f.shareability = res.cacheattrs.shareability; + + tlb_set_page_full(cs, mmu_idx, address, &res.f); + return true; + } else if (probe) { + return false; + } else { + /* now we have a real cpu fault */ + cpu_restore_state(cs, retaddr); + arm_deliver_fault(cpu, address, access_type, mmu_idx, fi); + } +} +#else +void arm_cpu_record_sigsegv(CPUState *cs, vaddr addr, + MMUAccessType access_type, + bool maperr, uintptr_t ra) +{ + ARMMMUFaultInfo fi = { + .type = maperr ? ARMFault_Translation : ARMFault_Permission, + .level = 3, + }; + ARMCPU *cpu = ARM_CPU(cs); + + /* + * We report both ESR and FAR to signal handlers. + * For now, it's easiest to deliver the fault normally. + */ + cpu_restore_state(cs, ra); + arm_deliver_fault(cpu, addr, access_type, MMU_USER_IDX, &fi); +} + +void arm_cpu_record_sigbus(CPUState *cs, vaddr addr, + MMUAccessType access_type, uintptr_t ra) +{ + arm_cpu_do_unaligned_access(cs, addr, access_type, MMU_USER_IDX, ra); +} +#endif /* !defined(CONFIG_USER_ONLY) */ |