| /* |
| * ARM helper routines |
| * |
| * Copyright (c) 2005-2007 CodeSourcery, LLC |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, see <http://www.gnu.org/licenses/>. |
| */ |
| #include "qemu/osdep.h" |
| #include "cpu.h" |
| #include "exec/helper-proto.h" |
| #include "internals.h" |
| #include "exec/cpu_ldst.h" |
| |
| #define SIGNBIT (uint32_t)0x80000000 |
| #define SIGNBIT64 ((uint64_t)1 << 63) |
| |
| static void raise_exception(CPUARMState *env, uint32_t excp, |
| uint32_t syndrome, uint32_t target_el) |
| { |
| CPUState *cs = CPU(arm_env_get_cpu(env)); |
| |
| assert(!excp_is_internal(excp)); |
| cs->exception_index = excp; |
| env->exception.syndrome = syndrome; |
| env->exception.target_el = target_el; |
| cpu_loop_exit(cs); |
| } |
| |
| static int exception_target_el(CPUARMState *env) |
| { |
| int target_el = MAX(1, arm_current_el(env)); |
| |
| /* No such thing as secure EL1 if EL3 is aarch32, so update the target EL |
| * to EL3 in this case. |
| */ |
| if (arm_is_secure(env) && !arm_el_is_aa64(env, 3) && target_el == 1) { |
| target_el = 3; |
| } |
| |
| return target_el; |
| } |
| |
| uint32_t HELPER(neon_tbl)(CPUARMState *env, uint32_t ireg, uint32_t def, |
| uint32_t rn, uint32_t maxindex) |
| { |
| uint32_t val; |
| uint32_t tmp; |
| int index; |
| int shift; |
| uint64_t *table; |
| table = (uint64_t *)&env->vfp.regs[rn]; |
| val = 0; |
| for (shift = 0; shift < 32; shift += 8) { |
| index = (ireg >> shift) & 0xff; |
| if (index < maxindex) { |
| tmp = (table[index >> 3] >> ((index & 7) << 3)) & 0xff; |
| val |= tmp << shift; |
| } else { |
| val |= def & (0xff << shift); |
| } |
| } |
| return val; |
| } |
| |
| #if !defined(CONFIG_USER_ONLY) |
| |
| /* try to fill the TLB and return an exception if error. If retaddr is |
| * NULL, it means that the function was called in C code (i.e. not |
| * from generated code or from helper.c) |
| */ |
| void tlb_fill(CPUState *cs, target_ulong addr, int is_write, int mmu_idx, |
| uintptr_t retaddr) |
| { |
| bool ret; |
| uint32_t fsr = 0; |
| ARMMMUFaultInfo fi = {}; |
| |
| ret = arm_tlb_fill(cs, addr, is_write, mmu_idx, &fsr, &fi); |
| if (unlikely(ret)) { |
| ARMCPU *cpu = ARM_CPU(cs); |
| CPUARMState *env = &cpu->env; |
| uint32_t syn, exc; |
| unsigned int target_el; |
| bool same_el; |
| |
| if (retaddr) { |
| /* now we have a real cpu fault */ |
| cpu_restore_state(cs, retaddr); |
| } |
| |
| target_el = exception_target_el(env); |
| if (fi.stage2) { |
| target_el = 2; |
| env->cp15.hpfar_el2 = extract64(fi.s2addr, 12, 47) << 4; |
| } |
| same_el = arm_current_el(env) == target_el; |
| /* AArch64 syndrome does not have an LPAE bit */ |
| syn = fsr & ~(1 << 9); |
| |
| /* For insn and data aborts we assume there is no instruction syndrome |
| * information; this is always true for exceptions reported to EL1. |
| */ |
| if (is_write == 2) { |
| syn = syn_insn_abort(same_el, 0, fi.s1ptw, syn); |
| exc = EXCP_PREFETCH_ABORT; |
| } else { |
| syn = syn_data_abort(same_el, 0, 0, fi.s1ptw, is_write == 1, syn); |
| if (is_write == 1 && 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, int is_write, |
| int is_user, uintptr_t retaddr) |
| { |
| ARMCPU *cpu = ARM_CPU(cs); |
| CPUARMState *env = &cpu->env; |
| int target_el; |
| bool same_el; |
| |
| if (retaddr) { |
| /* now we have a real cpu fault */ |
| cpu_restore_state(cs, retaddr); |
| } |
| |
| target_el = exception_target_el(env); |
| same_el = (arm_current_el(env) == target_el); |
| |
| env->exception.vaddress = vaddr; |
| |
| /* the DFSR for an alignment fault depends on whether we're using |
| * the LPAE long descriptor format, or the short descriptor format |
| */ |
| if (arm_s1_regime_using_lpae_format(env, cpu_mmu_index(env, false))) { |
| env->exception.fsr = 0x21; |
| } else { |
| env->exception.fsr = 0x1; |
| } |
| |
| if (is_write == 1 && arm_feature(env, ARM_FEATURE_V6)) { |
| env->exception.fsr |= (1 << 11); |
| } |
| |
| raise_exception(env, EXCP_DATA_ABORT, |
| syn_data_abort(same_el, 0, 0, 0, is_write == 1, 0x21), |
| target_el); |
| } |
| |
| #endif /* !defined(CONFIG_USER_ONLY) */ |
| |
| uint32_t HELPER(add_setq)(CPUARMState *env, uint32_t a, uint32_t b) |
| { |
| uint32_t res = a + b; |
| if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) |
| env->QF = 1; |
| return res; |
| } |
| |
| uint32_t HELPER(add_saturate)(CPUARMState *env, uint32_t a, uint32_t b) |
| { |
| uint32_t res = a + b; |
| if (((res ^ a) & SIGNBIT) && !((a ^ b) & SIGNBIT)) { |
| env->QF = 1; |
| res = ~(((int32_t)a >> 31) ^ SIGNBIT); |
| } |
| return res; |
| } |
| |
| uint32_t HELPER(sub_saturate)(CPUARMState *env, uint32_t a, uint32_t b) |
| { |
| uint32_t res = a - b; |
| if (((res ^ a) & SIGNBIT) && ((a ^ b) & SIGNBIT)) { |
| env->QF = 1; |
| res = ~(((int32_t)a >> 31) ^ SIGNBIT); |
| } |
| return res; |
| } |
| |
| uint32_t HELPER(double_saturate)(CPUARMState *env, int32_t val) |
| { |
| uint32_t res; |
| if (val >= 0x40000000) { |
| res = ~SIGNBIT; |
| env->QF = 1; |
| } else if (val <= (int32_t)0xc0000000) { |
| res = SIGNBIT; |
| env->QF = 1; |
| } else { |
| res = val << 1; |
| } |
| return res; |
| } |
| |
| uint32_t HELPER(add_usaturate)(CPUARMState *env, uint32_t a, uint32_t b) |
| { |
| uint32_t res = a + b; |
| if (res < a) { |
| env->QF = 1; |
| res = ~0; |
| } |
| return res; |
| } |
| |
| uint32_t HELPER(sub_usaturate)(CPUARMState *env, uint32_t a, uint32_t b) |
| { |
| uint32_t res = a - b; |
| if (res > a) { |
| env->QF = 1; |
| res = 0; |
| } |
| return res; |
| } |
| |
| /* Signed saturation. */ |
| static inline uint32_t do_ssat(CPUARMState *env, int32_t val, int shift) |
| { |
| int32_t top; |
| uint32_t mask; |
| |
| top = val >> shift; |
| mask = (1u << shift) - 1; |
| if (top > 0) { |
| env->QF = 1; |
| return mask; |
| } else if (top < -1) { |
| env->QF = 1; |
| return ~mask; |
| } |
| return val; |
| } |
| |
| /* Unsigned saturation. */ |
| static inline uint32_t do_usat(CPUARMState *env, int32_t val, int shift) |
| { |
| uint32_t max; |
| |
| max = (1u << shift) - 1; |
| if (val < 0) { |
| env->QF = 1; |
| return 0; |
| } else if (val > max) { |
| env->QF = 1; |
| return max; |
| } |
| return val; |
| } |
| |
| /* Signed saturate. */ |
| uint32_t HELPER(ssat)(CPUARMState *env, uint32_t x, uint32_t shift) |
| { |
| return do_ssat(env, x, shift); |
| } |
| |
| /* Dual halfword signed saturate. */ |
| uint32_t HELPER(ssat16)(CPUARMState *env, uint32_t x, uint32_t shift) |
| { |
| uint32_t res; |
| |
| res = (uint16_t)do_ssat(env, (int16_t)x, shift); |
| res |= do_ssat(env, ((int32_t)x) >> 16, shift) << 16; |
| return res; |
| } |
| |
| /* Unsigned saturate. */ |
| uint32_t HELPER(usat)(CPUARMState *env, uint32_t x, uint32_t shift) |
| { |
| return do_usat(env, x, shift); |
| } |
| |
| /* Dual halfword unsigned saturate. */ |
| uint32_t HELPER(usat16)(CPUARMState *env, uint32_t x, uint32_t shift) |
| { |
| uint32_t res; |
| |
| res = (uint16_t)do_usat(env, (int16_t)x, shift); |
| res |= do_usat(env, ((int32_t)x) >> 16, shift) << 16; |
| return res; |
| } |
| |
| /* Function checks whether WFx (WFI/WFE) instructions are set up to be trapped. |
| * The function returns the target EL (1-3) if the instruction is to be trapped; |
| * otherwise it returns 0 indicating it is not trapped. |
| */ |
| static inline int check_wfx_trap(CPUARMState *env, bool is_wfe) |
| { |
| int cur_el = arm_current_el(env); |
| uint64_t mask; |
| |
| /* If we are currently in EL0 then we need to check if SCTLR is set up for |
| * WFx instructions being trapped to EL1. These trap bits don't exist in v7. |
| */ |
| if (cur_el < 1 && arm_feature(env, ARM_FEATURE_V8)) { |
| int target_el; |
| |
| mask = is_wfe ? SCTLR_nTWE : SCTLR_nTWI; |
| if (arm_is_secure_below_el3(env) && !arm_el_is_aa64(env, 3)) { |
| /* Secure EL0 and Secure PL1 is at EL3 */ |
| target_el = 3; |
| } else { |
| target_el = 1; |
| } |
| |
| if (!(env->cp15.sctlr_el[target_el] & mask)) { |
| return target_el; |
| } |
| } |
| |
| /* We are not trapping to EL1; trap to EL2 if HCR_EL2 requires it |
| * No need for ARM_FEATURE check as if HCR_EL2 doesn't exist the |
| * bits will be zero indicating no trap. |
| */ |
| if (cur_el < 2 && !arm_is_secure(env)) { |
| mask = (is_wfe) ? HCR_TWE : HCR_TWI; |
| if (env->cp15.hcr_el2 & mask) { |
| return 2; |
| } |
| } |
| |
| /* We are not trapping to EL1 or EL2; trap to EL3 if SCR_EL3 requires it */ |
| if (cur_el < 3) { |
| mask = (is_wfe) ? SCR_TWE : SCR_TWI; |
| if (env->cp15.scr_el3 & mask) { |
| return 3; |
| } |
| } |
| |
| return 0; |
| } |
| |
| void HELPER(wfi)(CPUARMState *env) |
| { |
| CPUState *cs = CPU(arm_env_get_cpu(env)); |
| int target_el = check_wfx_trap(env, false); |
| |
| if (cpu_has_work(cs)) { |
| /* Don't bother to go into our "low power state" if |
| * we would just wake up immediately. |
| */ |
| return; |
| } |
| |
| if (target_el) { |
| env->pc -= 4; |
| raise_exception(env, EXCP_UDEF, syn_wfx(1, 0xe, 0), target_el); |
| } |
| |
| cs->exception_index = EXCP_HLT; |
| cs->halted = 1; |
| cpu_loop_exit(cs); |
| } |
| |
| void HELPER(wfe)(CPUARMState *env) |
| { |
| /* This is a hint instruction that is semantically different |
| * from YIELD even though we currently implement it identically. |
| * Don't actually halt the CPU, just yield back to top |
| * level loop. This is not going into a "low power state" |
| * (ie halting until some event occurs), so we never take |
| * a configurable trap to a different exception level. |
| */ |
| HELPER(yield)(env); |
| } |
| |
| void HELPER(yield)(CPUARMState *env) |
| { |
| ARMCPU *cpu = arm_env_get_cpu(env); |
| CPUState *cs = CPU(cpu); |
| |
| /* This is a non-trappable hint instruction that generally indicates |
| * that the guest is currently busy-looping. Yield control back to the |
| * top level loop so that a more deserving VCPU has a chance to run. |
| */ |
| cs->exception_index = EXCP_YIELD; |
| cpu_loop_exit(cs); |
| } |
| |
| /* Raise an internal-to-QEMU exception. This is limited to only |
| * those EXCP values which are special cases for QEMU to interrupt |
| * execution and not to be used for exceptions which are passed to |
| * the guest (those must all have syndrome information and thus should |
| * use exception_with_syndrome). |
| */ |
| void HELPER(exception_internal)(CPUARMState *env, uint32_t excp) |
| { |
| CPUState *cs = CPU(arm_env_get_cpu(env)); |
| |
| assert(excp_is_internal(excp)); |
| cs->exception_index = excp; |
| cpu_loop_exit(cs); |
| } |
| |
| /* Raise an exception with the specified syndrome register value */ |
| void HELPER(exception_with_syndrome)(CPUARMState *env, uint32_t excp, |
| uint32_t syndrome, uint32_t target_el) |
| { |
| raise_exception(env, excp, syndrome, target_el); |
| } |
| |
| uint32_t HELPER(cpsr_read)(CPUARMState *env) |
| { |
| return cpsr_read(env) & ~(CPSR_EXEC | CPSR_RESERVED); |
| } |
| |
| void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask) |
| { |
| cpsr_write(env, val, mask); |
| } |
| |
| /* Access to user mode registers from privileged modes. */ |
| uint32_t HELPER(get_user_reg)(CPUARMState *env, uint32_t regno) |
| { |
| uint32_t val; |
| |
| if (regno == 13) { |
| val = env->banked_r13[BANK_USRSYS]; |
| } else if (regno == 14) { |
| val = env->banked_r14[BANK_USRSYS]; |
| } else if (regno >= 8 |
| && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) { |
| val = env->usr_regs[regno - 8]; |
| } else { |
| val = env->regs[regno]; |
| } |
| return val; |
| } |
| |
| void HELPER(set_user_reg)(CPUARMState *env, uint32_t regno, uint32_t val) |
| { |
| if (regno == 13) { |
| env->banked_r13[BANK_USRSYS] = val; |
| } else if (regno == 14) { |
| env->banked_r14[BANK_USRSYS] = val; |
| } else if (regno >= 8 |
| && (env->uncached_cpsr & 0x1f) == ARM_CPU_MODE_FIQ) { |
| env->usr_regs[regno - 8] = val; |
| } else { |
| env->regs[regno] = val; |
| } |
| } |
| |
| void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t syndrome) |
| { |
| const ARMCPRegInfo *ri = rip; |
| int target_el; |
| |
| if (arm_feature(env, ARM_FEATURE_XSCALE) && ri->cp < 14 |
| && extract32(env->cp15.c15_cpar, ri->cp, 1) == 0) { |
| raise_exception(env, EXCP_UDEF, syndrome, exception_target_el(env)); |
| } |
| |
| if (!ri->accessfn) { |
| return; |
| } |
| |
| switch (ri->accessfn(env, ri)) { |
| case CP_ACCESS_OK: |
| return; |
| case CP_ACCESS_TRAP: |
| target_el = exception_target_el(env); |
| break; |
| case CP_ACCESS_TRAP_EL2: |
| /* Requesting a trap to EL2 when we're in EL3 or S-EL0/1 is |
| * a bug in the access function. |
| */ |
| assert(!arm_is_secure(env) && arm_current_el(env) != 3); |
| target_el = 2; |
| break; |
| case CP_ACCESS_TRAP_EL3: |
| target_el = 3; |
| break; |
| case CP_ACCESS_TRAP_UNCATEGORIZED: |
| target_el = exception_target_el(env); |
| syndrome = syn_uncategorized(); |
| break; |
| case CP_ACCESS_TRAP_UNCATEGORIZED_EL2: |
| target_el = 2; |
| syndrome = syn_uncategorized(); |
| break; |
| case CP_ACCESS_TRAP_UNCATEGORIZED_EL3: |
| target_el = 3; |
| syndrome = syn_uncategorized(); |
| break; |
| default: |
| g_assert_not_reached(); |
| } |
| |
| raise_exception(env, EXCP_UDEF, syndrome, target_el); |
| } |
| |
| void HELPER(set_cp_reg)(CPUARMState *env, void *rip, uint32_t value) |
| { |
| const ARMCPRegInfo *ri = rip; |
| |
| ri->writefn(env, ri, value); |
| } |
| |
| uint32_t HELPER(get_cp_reg)(CPUARMState *env, void *rip) |
| { |
| const ARMCPRegInfo *ri = rip; |
| |
| return ri->readfn(env, ri); |
| } |
| |
| void HELPER(set_cp_reg64)(CPUARMState *env, void *rip, uint64_t value) |
| { |
| const ARMCPRegInfo *ri = rip; |
| |
| ri->writefn(env, ri, value); |
| } |
| |
| uint64_t HELPER(get_cp_reg64)(CPUARMState *env, void *rip) |
| { |
| const ARMCPRegInfo *ri = rip; |
| |
| return ri->readfn(env, ri); |
| } |
| |
| void HELPER(msr_i_pstate)(CPUARMState *env, uint32_t op, uint32_t imm) |
| { |
| /* MSR_i to update PSTATE. This is OK from EL0 only if UMA is set. |
| * Note that SPSel is never OK from EL0; we rely on handle_msr_i() |
| * to catch that case at translate time. |
| */ |
| if (arm_current_el(env) == 0 && !(env->cp15.sctlr_el[1] & SCTLR_UMA)) { |
| uint32_t syndrome = syn_aa64_sysregtrap(0, extract32(op, 0, 3), |
| extract32(op, 3, 3), 4, |
| imm, 0x1f, 0); |
| raise_exception(env, EXCP_UDEF, syndrome, exception_target_el(env)); |
| } |
| |
| switch (op) { |
| case 0x05: /* SPSel */ |
| update_spsel(env, imm); |
| break; |
| case 0x1e: /* DAIFSet */ |
| env->daif |= (imm << 6) & PSTATE_DAIF; |
| break; |
| case 0x1f: /* DAIFClear */ |
| env->daif &= ~((imm << 6) & PSTATE_DAIF); |
| break; |
| default: |
| g_assert_not_reached(); |
| } |
| } |
| |
| void HELPER(clear_pstate_ss)(CPUARMState *env) |
| { |
| env->pstate &= ~PSTATE_SS; |
| } |
| |
| void HELPER(pre_hvc)(CPUARMState *env) |
| { |
| ARMCPU *cpu = arm_env_get_cpu(env); |
| int cur_el = arm_current_el(env); |
| /* FIXME: Use actual secure state. */ |
| bool secure = false; |
| bool undef; |
| |
| if (arm_is_psci_call(cpu, EXCP_HVC)) { |
| /* If PSCI is enabled and this looks like a valid PSCI call then |
| * that overrides the architecturally mandated HVC behaviour. |
| */ |
| return; |
| } |
| |
| if (!arm_feature(env, ARM_FEATURE_EL2)) { |
| /* If EL2 doesn't exist, HVC always UNDEFs */ |
| undef = true; |
| } else if (arm_feature(env, ARM_FEATURE_EL3)) { |
| /* EL3.HCE has priority over EL2.HCD. */ |
| undef = !(env->cp15.scr_el3 & SCR_HCE); |
| } else { |
| undef = env->cp15.hcr_el2 & HCR_HCD; |
| } |
| |
| /* In ARMv7 and ARMv8/AArch32, HVC is undef in secure state. |
| * For ARMv8/AArch64, HVC is allowed in EL3. |
| * Note that we've already trapped HVC from EL0 at translation |
| * time. |
| */ |
| if (secure && (!is_a64(env) || cur_el == 1)) { |
| undef = true; |
| } |
| |
| if (undef) { |
| raise_exception(env, EXCP_UDEF, syn_uncategorized(), |
| exception_target_el(env)); |
| } |
| } |
| |
| void HELPER(pre_smc)(CPUARMState *env, uint32_t syndrome) |
| { |
| ARMCPU *cpu = arm_env_get_cpu(env); |
| int cur_el = arm_current_el(env); |
| bool secure = arm_is_secure(env); |
| bool smd = env->cp15.scr_el3 & SCR_SMD; |
| /* On ARMv8 AArch32, SMD only applies to NS state. |
| * On ARMv7 SMD only applies to NS state and only if EL2 is available. |
| * For ARMv7 non EL2, we force SMD to zero so we don't need to re-check |
| * the EL2 condition here. |
| */ |
| bool undef = is_a64(env) ? smd : (!secure && smd); |
| |
| if (arm_is_psci_call(cpu, EXCP_SMC)) { |
| /* If PSCI is enabled and this looks like a valid PSCI call then |
| * that overrides the architecturally mandated SMC behaviour. |
| */ |
| return; |
| } |
| |
| if (!arm_feature(env, ARM_FEATURE_EL3)) { |
| /* If we have no EL3 then SMC always UNDEFs */ |
| undef = true; |
| } else if (!secure && cur_el == 1 && (env->cp15.hcr_el2 & HCR_TSC)) { |
| /* In NS EL1, HCR controlled routing to EL2 has priority over SMD. */ |
| raise_exception(env, EXCP_HYP_TRAP, syndrome, 2); |
| } |
| |
| if (undef) { |
| raise_exception(env, EXCP_UDEF, syn_uncategorized(), |
| exception_target_el(env)); |
| } |
| } |
| |
| static int el_from_spsr(uint32_t spsr) |
| { |
| /* Return the exception level that this SPSR is requesting a return to, |
| * or -1 if it is invalid (an illegal return) |
| */ |
| if (spsr & PSTATE_nRW) { |
| switch (spsr & CPSR_M) { |
| case ARM_CPU_MODE_USR: |
| return 0; |
| case ARM_CPU_MODE_HYP: |
| return 2; |
| case ARM_CPU_MODE_FIQ: |
| case ARM_CPU_MODE_IRQ: |
| case ARM_CPU_MODE_SVC: |
| case ARM_CPU_MODE_ABT: |
| case ARM_CPU_MODE_UND: |
| case ARM_CPU_MODE_SYS: |
| return 1; |
| case ARM_CPU_MODE_MON: |
| /* Returning to Mon from AArch64 is never possible, |
| * so this is an illegal return. |
| */ |
| default: |
| return -1; |
| } |
| } else { |
| if (extract32(spsr, 1, 1)) { |
| /* Return with reserved M[1] bit set */ |
| return -1; |
| } |
| if (extract32(spsr, 0, 4) == 1) { |
| /* return to EL0 with M[0] bit set */ |
| return -1; |
| } |
| return extract32(spsr, 2, 2); |
| } |
| } |
| |
| void HELPER(exception_return)(CPUARMState *env) |
| { |
| int cur_el = arm_current_el(env); |
| unsigned int spsr_idx = aarch64_banked_spsr_index(cur_el); |
| uint32_t spsr = env->banked_spsr[spsr_idx]; |
| int new_el; |
| bool return_to_aa64 = (spsr & PSTATE_nRW) == 0; |
| |
| aarch64_save_sp(env, cur_el); |
| |
| env->exclusive_addr = -1; |
| |
| /* We must squash the PSTATE.SS bit to zero unless both of the |
| * following hold: |
| * 1. debug exceptions are currently disabled |
| * 2. singlestep will be active in the EL we return to |
| * We check 1 here and 2 after we've done the pstate/cpsr write() to |
| * transition to the EL we're going to. |
| */ |
| if (arm_generate_debug_exceptions(env)) { |
| spsr &= ~PSTATE_SS; |
| } |
| |
| new_el = el_from_spsr(spsr); |
| if (new_el == -1) { |
| goto illegal_return; |
| } |
| if (new_el > cur_el |
| || (new_el == 2 && !arm_feature(env, ARM_FEATURE_EL2))) { |
| /* Disallow return to an EL which is unimplemented or higher |
| * than the current one. |
| */ |
| goto illegal_return; |
| } |
| |
| if (new_el != 0 && arm_el_is_aa64(env, new_el) != return_to_aa64) { |
| /* Return to an EL which is configured for a different register width */ |
| goto illegal_return; |
| } |
| |
| if (new_el == 2 && arm_is_secure_below_el3(env)) { |
| /* Return to the non-existent secure-EL2 */ |
| goto illegal_return; |
| } |
| |
| if (new_el == 1 && (env->cp15.hcr_el2 & HCR_TGE) |
| && !arm_is_secure_below_el3(env)) { |
| goto illegal_return; |
| } |
| |
| if (!return_to_aa64) { |
| env->aarch64 = 0; |
| env->uncached_cpsr = spsr & CPSR_M; |
| cpsr_write(env, spsr, ~0); |
| if (!arm_singlestep_active(env)) { |
| env->uncached_cpsr &= ~PSTATE_SS; |
| } |
| aarch64_sync_64_to_32(env); |
| |
| if (spsr & CPSR_T) { |
| env->regs[15] = env->elr_el[cur_el] & ~0x1; |
| } else { |
| env->regs[15] = env->elr_el[cur_el] & ~0x3; |
| } |
| } else { |
| env->aarch64 = 1; |
| pstate_write(env, spsr); |
| if (!arm_singlestep_active(env)) { |
| env->pstate &= ~PSTATE_SS; |
| } |
| aarch64_restore_sp(env, new_el); |
| env->pc = env->elr_el[cur_el]; |
| } |
| |
| return; |
| |
| illegal_return: |
| /* Illegal return events of various kinds have architecturally |
| * mandated behaviour: |
| * restore NZCV and DAIF from SPSR_ELx |
| * set PSTATE.IL |
| * restore PC from ELR_ELx |
| * no change to exception level, execution state or stack pointer |
| */ |
| env->pstate |= PSTATE_IL; |
| env->pc = env->elr_el[cur_el]; |
| spsr &= PSTATE_NZCV | PSTATE_DAIF; |
| spsr |= pstate_read(env) & ~(PSTATE_NZCV | PSTATE_DAIF); |
| pstate_write(env, spsr); |
| if (!arm_singlestep_active(env)) { |
| env->pstate &= ~PSTATE_SS; |
| } |
| } |
| |
| /* Return true if the linked breakpoint entry lbn passes its checks */ |
| static bool linked_bp_matches(ARMCPU *cpu, int lbn) |
| { |
| CPUARMState *env = &cpu->env; |
| uint64_t bcr = env->cp15.dbgbcr[lbn]; |
| int brps = extract32(cpu->dbgdidr, 24, 4); |
| int ctx_cmps = extract32(cpu->dbgdidr, 20, 4); |
| int bt; |
| uint32_t contextidr; |
| |
| /* Links to unimplemented or non-context aware breakpoints are |
| * CONSTRAINED UNPREDICTABLE: either behave as if disabled, or |
| * as if linked to an UNKNOWN context-aware breakpoint (in which |
| * case DBGWCR<n>_EL1.LBN must indicate that breakpoint). |
| * We choose the former. |
| */ |
| if (lbn > brps || lbn < (brps - ctx_cmps)) { |
| return false; |
| } |
| |
| bcr = env->cp15.dbgbcr[lbn]; |
| |
| if (extract64(bcr, 0, 1) == 0) { |
| /* Linked breakpoint disabled : generate no events */ |
| return false; |
| } |
| |
| bt = extract64(bcr, 20, 4); |
| |
| /* We match the whole register even if this is AArch32 using the |
| * short descriptor format (in which case it holds both PROCID and ASID), |
| * since we don't implement the optional v7 context ID masking. |
| */ |
| contextidr = extract64(env->cp15.contextidr_el[1], 0, 32); |
| |
| switch (bt) { |
| case 3: /* linked context ID match */ |
| if (arm_current_el(env) > 1) { |
| /* Context matches never fire in EL2 or (AArch64) EL3 */ |
| return false; |
| } |
| return (contextidr == extract64(env->cp15.dbgbvr[lbn], 0, 32)); |
| case 5: /* linked address mismatch (reserved in AArch64) */ |
| case 9: /* linked VMID match (reserved if no EL2) */ |
| case 11: /* linked context ID and VMID match (reserved if no EL2) */ |
| default: |
| /* Links to Unlinked context breakpoints must generate no |
| * events; we choose to do the same for reserved values too. |
| */ |
| return false; |
| } |
| |
| return false; |
| } |
| |
| static bool bp_wp_matches(ARMCPU *cpu, int n, bool is_wp) |
| { |
| CPUARMState *env = &cpu->env; |
| uint64_t cr; |
| int pac, hmc, ssc, wt, lbn; |
| /* Note that for watchpoints the check is against the CPU security |
| * state, not the S/NS attribute on the offending data access. |
| */ |
| bool is_secure = arm_is_secure(env); |
| int access_el = arm_current_el(env); |
| |
| if (is_wp) { |
| CPUWatchpoint *wp = env->cpu_watchpoint[n]; |
| |
| if (!wp || !(wp->flags & BP_WATCHPOINT_HIT)) { |
| return false; |
| } |
| cr = env->cp15.dbgwcr[n]; |
| if (wp->hitattrs.user) { |
| /* The LDRT/STRT/LDT/STT "unprivileged access" instructions should |
| * match watchpoints as if they were accesses done at EL0, even if |
| * the CPU is at EL1 or higher. |
| */ |
| access_el = 0; |
| } |
| } else { |
| uint64_t pc = is_a64(env) ? env->pc : env->regs[15]; |
| |
| if (!env->cpu_breakpoint[n] || env->cpu_breakpoint[n]->pc != pc) { |
| return false; |
| } |
| cr = env->cp15.dbgbcr[n]; |
| } |
| /* The WATCHPOINT_HIT flag guarantees us that the watchpoint is |
| * enabled and that the address and access type match; for breakpoints |
| * we know the address matched; check the remaining fields, including |
| * linked breakpoints. We rely on WCR and BCR having the same layout |
| * for the LBN, SSC, HMC, PAC/PMC and is-linked fields. |
| * Note that some combinations of {PAC, HMC, SSC} are reserved and |
| * must act either like some valid combination or as if the watchpoint |
| * were disabled. We choose the former, and use this together with |
| * the fact that EL3 must always be Secure and EL2 must always be |
| * Non-Secure to simplify the code slightly compared to the full |
| * table in the ARM ARM. |
| */ |
| pac = extract64(cr, 1, 2); |
| hmc = extract64(cr, 13, 1); |
| ssc = extract64(cr, 14, 2); |
| |
| switch (ssc) { |
| case 0: |
| break; |
| case 1: |
| case 3: |
| if (is_secure) { |
| return false; |
| } |
| break; |
| case 2: |
| if (!is_secure) { |
| return false; |
| } |
| break; |
| } |
| |
| switch (access_el) { |
| case 3: |
| case 2: |
| if (!hmc) { |
| return false; |
| } |
| break; |
| case 1: |
| if (extract32(pac, 0, 1) == 0) { |
| return false; |
| } |
| break; |
| case 0: |
| if (extract32(pac, 1, 1) == 0) { |
| return false; |
| } |
| break; |
| default: |
| g_assert_not_reached(); |
| } |
| |
| wt = extract64(cr, 20, 1); |
| lbn = extract64(cr, 16, 4); |
| |
| if (wt && !linked_bp_matches(cpu, lbn)) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static bool check_watchpoints(ARMCPU *cpu) |
| { |
| CPUARMState *env = &cpu->env; |
| int n; |
| |
| /* If watchpoints are disabled globally or we can't take debug |
| * exceptions here then watchpoint firings are ignored. |
| */ |
| if (extract32(env->cp15.mdscr_el1, 15, 1) == 0 |
| || !arm_generate_debug_exceptions(env)) { |
| return false; |
| } |
| |
| for (n = 0; n < ARRAY_SIZE(env->cpu_watchpoint); n++) { |
| if (bp_wp_matches(cpu, n, true)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| static bool check_breakpoints(ARMCPU *cpu) |
| { |
| CPUARMState *env = &cpu->env; |
| int n; |
| |
| /* If breakpoints are disabled globally or we can't take debug |
| * exceptions here then breakpoint firings are ignored. |
| */ |
| if (extract32(env->cp15.mdscr_el1, 15, 1) == 0 |
| || !arm_generate_debug_exceptions(env)) { |
| return false; |
| } |
| |
| for (n = 0; n < ARRAY_SIZE(env->cpu_breakpoint); n++) { |
| if (bp_wp_matches(cpu, n, false)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void HELPER(check_breakpoints)(CPUARMState *env) |
| { |
| ARMCPU *cpu = arm_env_get_cpu(env); |
| |
| if (check_breakpoints(cpu)) { |
| HELPER(exception_internal(env, EXCP_DEBUG)); |
| } |
| } |
| |
| void arm_debug_excp_handler(CPUState *cs) |
| { |
| /* Called by core code when a watchpoint or breakpoint fires; |
| * need to check which one and raise the appropriate exception. |
| */ |
| ARMCPU *cpu = ARM_CPU(cs); |
| CPUARMState *env = &cpu->env; |
| CPUWatchpoint *wp_hit = cs->watchpoint_hit; |
| |
| if (wp_hit) { |
| if (wp_hit->flags & BP_CPU) { |
| cs->watchpoint_hit = NULL; |
| if (check_watchpoints(cpu)) { |
| bool wnr = (wp_hit->flags & BP_WATCHPOINT_HIT_WRITE) != 0; |
| bool same_el = arm_debug_target_el(env) == arm_current_el(env); |
| |
| if (extended_addresses_enabled(env)) { |
| env->exception.fsr = (1 << 9) | 0x22; |
| } else { |
| env->exception.fsr = 0x2; |
| } |
| env->exception.vaddress = wp_hit->hitaddr; |
| raise_exception(env, EXCP_DATA_ABORT, |
| syn_watchpoint(same_el, 0, wnr), |
| arm_debug_target_el(env)); |
| } else { |
| cpu_resume_from_signal(cs, NULL); |
| } |
| } |
| } else { |
| uint64_t pc = is_a64(env) ? env->pc : env->regs[15]; |
| bool same_el = (arm_debug_target_el(env) == arm_current_el(env)); |
| |
| /* (1) GDB breakpoints should be handled first. |
| * (2) Do not raise a CPU exception if no CPU breakpoint has fired, |
| * since singlestep is also done by generating a debug internal |
| * exception. |
| */ |
| if (cpu_breakpoint_test(cs, pc, BP_GDB) |
| || !cpu_breakpoint_test(cs, pc, BP_CPU)) { |
| return; |
| } |
| |
| if (extended_addresses_enabled(env)) { |
| env->exception.fsr = (1 << 9) | 0x22; |
| } else { |
| env->exception.fsr = 0x2; |
| } |
| /* FAR is UNKNOWN, so doesn't need setting */ |
| raise_exception(env, EXCP_PREFETCH_ABORT, |
| syn_breakpoint(same_el), |
| arm_debug_target_el(env)); |
| } |
| } |
| |
| /* ??? Flag setting arithmetic is awkward because we need to do comparisons. |
| The only way to do that in TCG is a conditional branch, which clobbers |
| all our temporaries. For now implement these as helper functions. */ |
| |
| /* Similarly for variable shift instructions. */ |
| |
| uint32_t HELPER(shl_cc)(CPUARMState *env, uint32_t x, uint32_t i) |
| { |
| int shift = i & 0xff; |
| if (shift >= 32) { |
| if (shift == 32) |
| env->CF = x & 1; |
| else |
| env->CF = 0; |
| return 0; |
| } else if (shift != 0) { |
| env->CF = (x >> (32 - shift)) & 1; |
| return x << shift; |
| } |
| return x; |
| } |
| |
| uint32_t HELPER(shr_cc)(CPUARMState *env, uint32_t x, uint32_t i) |
| { |
| int shift = i & 0xff; |
| if (shift >= 32) { |
| if (shift == 32) |
| env->CF = (x >> 31) & 1; |
| else |
| env->CF = 0; |
| return 0; |
| } else if (shift != 0) { |
| env->CF = (x >> (shift - 1)) & 1; |
| return x >> shift; |
| } |
| return x; |
| } |
| |
| uint32_t HELPER(sar_cc)(CPUARMState *env, uint32_t x, uint32_t i) |
| { |
| int shift = i & 0xff; |
| if (shift >= 32) { |
| env->CF = (x >> 31) & 1; |
| return (int32_t)x >> 31; |
| } else if (shift != 0) { |
| env->CF = (x >> (shift - 1)) & 1; |
| return (int32_t)x >> shift; |
| } |
| return x; |
| } |
| |
| uint32_t HELPER(ror_cc)(CPUARMState *env, uint32_t x, uint32_t i) |
| { |
| int shift1, shift; |
| shift1 = i & 0xff; |
| shift = shift1 & 0x1f; |
| if (shift == 0) { |
| if (shift1 != 0) |
| env->CF = (x >> 31) & 1; |
| return x; |
| } else { |
| env->CF = (x >> (shift - 1)) & 1; |
| return ((uint32_t)x >> shift) | (x << (32 - shift)); |
| } |
| } |
