| Message ID | 1456762734-23939-1-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | New |
| Headers | show |
On 29.02.2016 19:18, Peter Maydell wrote: > Starting with the ARMv7 Virtualization Extensions, the A32 and T32 > instruction sets provide instructions "MSR (banked)" and "MRS > (banked)" which can be used to access registers for a mode other > than the current one: > * R<m>_<mode> > * ELR_hyp > * SPSR_<mode> > > Implement the missing instructions. Likely, there is no disassembling support in QEMU for these instructions as well. Are you going to add it? Best regards, Sergey > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > We don't support EL2 yet, but you can get at these on a v8 CPU in > 32-bit EL1 if EL3 is enabled. Obviously there's not going to be much > 32-bit EL1 code out there that uses the insns though, as it wouldn't > work on v7 if it did...
On 29 February 2016 at 16:24, Sergey Fedorov <serge.fdrv@gmail.com> wrote: > On 29.02.2016 19:18, Peter Maydell wrote: >> Starting with the ARMv7 Virtualization Extensions, the A32 and T32 >> instruction sets provide instructions "MSR (banked)" and "MRS >> (banked)" which can be used to access registers for a mode other >> than the current one: >> * R<m>_<mode> >> * ELR_hyp >> * SPSR_<mode> >> >> Implement the missing instructions. > > Likely, there is no disassembling support in QEMU for these instructions > as well. Are you going to add it? No, I don't plan to. thanks -- PMM
On Mon, Feb 29, 2016 at 04:18:54PM +0000, Peter Maydell wrote: > Starting with the ARMv7 Virtualization Extensions, the A32 and T32 > instruction sets provide instructions "MSR (banked)" and "MRS > (banked)" which can be used to access registers for a mode other > than the current one: > * R<m>_<mode> > * ELR_hyp > * SPSR_<mode> > > Implement the missing instructions. Wow, these insns were a bit messy to follow... Anyway, AFAIK this looks OK: Acked-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com> > > Signed-off-by: Peter Maydell <peter.maydell@linaro.org> > --- > We don't support EL2 yet, but you can get at these on a v8 CPU in > 32-bit EL1 if EL3 is enabled. Obviously there's not going to be much > 32-bit EL1 code out there that uses the insns though, as it wouldn't > work on v7 if it did... > > target-arm/helper.h | 3 + > target-arm/op_helper.c | 120 ++++++++++++++++++++++++ > target-arm/translate.c | 246 ++++++++++++++++++++++++++++++++++++++++++++++++- > 3 files changed, 366 insertions(+), 3 deletions(-) > > diff --git a/target-arm/helper.h b/target-arm/helper.h > index ea13202..de3c644 100644 > --- a/target-arm/helper.h > +++ b/target-arm/helper.h > @@ -76,6 +76,9 @@ DEF_HELPER_1(exception_return, void, env) > DEF_HELPER_2(get_r13_banked, i32, env, i32) > DEF_HELPER_3(set_r13_banked, void, env, i32, i32) > > +DEF_HELPER_3(mrs_banked, i32, env, i32, i32) > +DEF_HELPER_4(msr_banked, void, env, i32, i32, i32) > + > DEF_HELPER_2(get_user_reg, i32, env, i32) > DEF_HELPER_3(set_user_reg, void, env, i32, i32) > > diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c > index 4881e34..a2afdd8 100644 > --- a/target-arm/op_helper.c > +++ b/target-arm/op_helper.c > @@ -489,6 +489,126 @@ uint32_t HELPER(get_r13_banked)(CPUARMState *env, uint32_t mode) > } > } > > +static void msr_mrs_banked_exc_checks(CPUARMState *env, uint32_t tgtmode, > + uint32_t regno) > +{ > + /* Raise an exception if the requested access is one of the UNPREDICTABLE > + * cases; otherwise return. This broadly corresponds to the pseudocode > + * BankedRegisterAccessValid() and SPSRAccessValid(), > + * except that we have already handled some cases at translate time. > + */ > + int curmode = env->uncached_cpsr & CPSR_M; > + > + if (curmode == tgtmode) { > + goto undef; > + } > + > + if (tgtmode == ARM_CPU_MODE_USR) { > + switch (regno) { > + case 8 ... 12: > + if (curmode != ARM_CPU_MODE_FIQ) { > + goto undef; > + } > + break; > + case 13: > + if (curmode == ARM_CPU_MODE_SYS) { > + goto undef; > + } > + break; > + case 14: > + if (curmode == ARM_CPU_MODE_HYP || curmode == ARM_CPU_MODE_SYS) { > + goto undef; > + } > + break; > + default: > + break; > + } > + } > + > + if (tgtmode == ARM_CPU_MODE_HYP) { > + switch (regno) { > + case 17: /* ELR_Hyp */ > + if (curmode != ARM_CPU_MODE_HYP && curmode != ARM_CPU_MODE_MON) { > + goto undef; > + } > + break; > + default: > + if (curmode != ARM_CPU_MODE_MON) { > + goto undef; > + } > + break; > + } > + } > + > + return; > + > +undef: > + raise_exception(env, EXCP_UDEF, syn_uncategorized(), > + exception_target_el(env)); > +} > + > +void HELPER(msr_banked)(CPUARMState *env, uint32_t value, uint32_t tgtmode, > + uint32_t regno) > +{ > + msr_mrs_banked_exc_checks(env, tgtmode, regno); > + > + switch (regno) { > + case 16: /* SPSRs */ > + env->banked_spsr[bank_number(tgtmode)] = value; > + break; > + case 17: /* ELR_Hyp */ > + env->elr_el[2] = value; > + break; > + case 13: > + env->banked_r13[bank_number(tgtmode)] = value; > + break; > + case 14: > + env->banked_r14[bank_number(tgtmode)] = value; > + break; > + case 8 ... 12: > + switch (tgtmode) { > + case ARM_CPU_MODE_USR: > + env->usr_regs[regno - 8] = value; > + break; > + case ARM_CPU_MODE_FIQ: > + env->fiq_regs[regno - 8] = value; > + break; > + default: > + g_assert_not_reached(); > + } > + break; > + default: > + g_assert_not_reached(); > + } > +} > + > +uint32_t HELPER(mrs_banked)(CPUARMState *env, uint32_t tgtmode, uint32_t regno) > +{ > + msr_mrs_banked_exc_checks(env, tgtmode, regno); > + > + switch (regno) { > + case 16: /* SPSRs */ > + return env->banked_spsr[bank_number(tgtmode)]; > + case 17: /* ELR_Hyp */ > + return env->elr_el[2]; > + case 13: > + return env->banked_r13[bank_number(tgtmode)]; > + case 14: > + return env->banked_r14[bank_number(tgtmode)]; > + case 8 ... 12: > + switch (tgtmode) { > + case ARM_CPU_MODE_USR: > + return env->usr_regs[regno - 8]; > + case ARM_CPU_MODE_FIQ: > + return env->fiq_regs[regno - 8]; > + default: > + g_assert_not_reached(); > + } > + default: > + g_assert_not_reached(); > + } > +} > + > void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t syndrome, > uint32_t isread) > { > diff --git a/target-arm/translate.c b/target-arm/translate.c > index 413f7de..a8dd490 100644 > --- a/target-arm/translate.c > +++ b/target-arm/translate.c > @@ -4088,6 +4088,195 @@ static int gen_set_psr_im(DisasContext *s, uint32_t mask, int spsr, uint32_t val > return gen_set_psr(s, mask, spsr, tmp); > } > > +static bool msr_banked_access_decode(DisasContext *s, int r, int sysm, int rn, > + int *tgtmode, int *regno) > +{ > + /* Decode the r and sysm fields of MSR/MRS banked accesses into > + * the target mode and register number, and identify the various > + * unpredictable cases. > + * MSR (banked) and MRS (banked) are CONSTRAINED UNPREDICTABLE if: > + * + executed in user mode > + * + using R15 as the src/dest register > + * + accessing an unimplemented register > + * + accessing a register that's inaccessible at current PL/security state* > + * + accessing a register that you could access with a different insn > + * We choose to UNDEF in all these cases. > + * Since we don't know which of the various AArch32 modes we are in > + * we have to defer some checks to runtime. > + * Accesses to Monitor mode registers from Secure EL1 (which implies > + * that EL3 is AArch64) must trap to EL3. > + * > + * If the access checks fail this function will emit code to take > + * an exception and return false. Otherwise it will return true, > + * and set *tgtmode and *regno appropriately. > + */ > + int exc_target = default_exception_el(s); > + > + /* These instructions are present only in ARMv8, or in ARMv7 with the > + * Virtualization Extensions. > + */ > + if (!arm_dc_feature(s, ARM_FEATURE_V8) && > + !arm_dc_feature(s, ARM_FEATURE_EL2)) { > + goto undef; > + } > + > + if (IS_USER(s) || rn == 15) { > + goto undef; > + } > + > + /* The table in the v8 ARM ARM section F5.2.3 describes the encoding > + * of registers into (r, sysm). > + */ > + if (r) { > + /* SPSRs for other modes */ > + switch (sysm) { > + case 0xe: /* SPSR_fiq */ > + *tgtmode = ARM_CPU_MODE_FIQ; > + break; > + case 0x10: /* SPSR_irq */ > + *tgtmode = ARM_CPU_MODE_IRQ; > + break; > + case 0x12: /* SPSR_svc */ > + *tgtmode = ARM_CPU_MODE_SVC; > + break; > + case 0x14: /* SPSR_abt */ > + *tgtmode = ARM_CPU_MODE_ABT; > + break; > + case 0x16: /* SPSR_und */ > + *tgtmode = ARM_CPU_MODE_UND; > + break; > + case 0x1c: /* SPSR_mon */ > + *tgtmode = ARM_CPU_MODE_MON; > + break; > + case 0x1e: /* SPSR_hyp */ > + *tgtmode = ARM_CPU_MODE_HYP; > + break; > + default: /* unallocated */ > + goto undef; > + } > + /* We arbitrarily assign SPSR a register number of 16. */ > + *regno = 16; > + } else { > + /* general purpose registers for other modes */ > + switch (sysm) { > + case 0x0 ... 0x6: /* 0b00xxx : r8_usr ... r14_usr */ > + *tgtmode = ARM_CPU_MODE_USR; > + *regno = sysm + 8; > + break; > + case 0x8 ... 0xe: /* 0b01xxx : r8_fiq ... r14_fiq */ > + *tgtmode = ARM_CPU_MODE_FIQ; > + *regno = sysm; > + break; > + case 0x10 ... 0x11: /* 0b1000x : r14_irq, r13_irq */ > + *tgtmode = ARM_CPU_MODE_IRQ; > + *regno = sysm & 1 ? 13 : 14; > + break; > + case 0x12 ... 0x13: /* 0b1001x : r14_svc, r13_svc */ > + *tgtmode = ARM_CPU_MODE_SVC; > + *regno = sysm & 1 ? 13 : 14; > + break; > + case 0x14 ... 0x15: /* 0b1010x : r14_abt, r13_abt */ > + *tgtmode = ARM_CPU_MODE_ABT; > + *regno = sysm & 1 ? 13 : 14; > + break; > + case 0x16 ... 0x17: /* 0b1011x : r14_und, r13_und */ > + *tgtmode = ARM_CPU_MODE_UND; > + *regno = sysm & 1 ? 13 : 14; > + break; > + case 0x1c ... 0x1d: /* 0b1110x : r14_mon, r13_mon */ > + *tgtmode = ARM_CPU_MODE_MON; > + *regno = sysm & 1 ? 13 : 14; > + break; > + case 0x1e ... 0x1f: /* 0b1111x : elr_hyp, r13_hyp */ > + *tgtmode = ARM_CPU_MODE_HYP; > + /* Arbitrarily pick 17 for ELR_Hyp (which is not a banked LR!) */ > + *regno = sysm & 1 ? 13 : 17; > + break; > + default: /* unallocated */ > + goto undef; > + } > + } > + > + /* Catch the 'accessing inaccessible register' cases we can detect > + * at translate time. > + */ > + switch (*tgtmode) { > + case ARM_CPU_MODE_MON: > + if (!arm_dc_feature(s, ARM_FEATURE_EL3) || s->ns) { > + goto undef; > + } > + if (s->current_el == 1) { > + /* If we're in Secure EL1 (which implies that EL3 is AArch64) > + * then accesses to Mon registers trap to EL3 > + */ > + exc_target = 3; > + goto undef; > + } > + break; > + case ARM_CPU_MODE_HYP: > + /* Note that we can forbid accesses from EL2 here because they > + * must be from Hyp mode itself > + */ > + if (!arm_dc_feature(s, ARM_FEATURE_EL2) || s->current_el < 3) { > + goto undef; > + } > + break; > + default: > + break; > + } > + > + return true; > + > +undef: > + /* If we get here then some access check did not pass */ > + gen_exception_insn(s, 4, EXCP_UDEF, syn_uncategorized(), exc_target); > + return false; > +} > + > +static void gen_msr_banked(DisasContext *s, int r, int sysm, int rn) > +{ > + TCGv_i32 tcg_reg, tcg_tgtmode, tcg_regno; > + int tgtmode, regno; > + > + if (!msr_banked_access_decode(s, r, sysm, rn, &tgtmode, ®no)) { > + return; > + } > + > + /* Sync state because msr_banked() can raise exceptions */ > + gen_set_condexec(s); > + gen_set_pc_im(s, s->pc - 4); > + tcg_reg = load_reg(s, rn); > + tcg_tgtmode = tcg_const_i32(tgtmode); > + tcg_regno = tcg_const_i32(regno); > + gen_helper_msr_banked(cpu_env, tcg_reg, tcg_tgtmode, tcg_regno); > + tcg_temp_free_i32(tcg_tgtmode); > + tcg_temp_free_i32(tcg_regno); > + tcg_temp_free_i32(tcg_reg); > + s->is_jmp = DISAS_UPDATE; > +} > + > +static void gen_mrs_banked(DisasContext *s, int r, int sysm, int rn) > +{ > + TCGv_i32 tcg_reg, tcg_tgtmode, tcg_regno; > + int tgtmode, regno; > + > + if (!msr_banked_access_decode(s, r, sysm, rn, &tgtmode, ®no)) { > + return; > + } > + > + /* Sync state because mrs_banked() can raise exceptions */ > + gen_set_condexec(s); > + gen_set_pc_im(s, s->pc - 4); > + tcg_reg = tcg_temp_new_i32(); > + tcg_tgtmode = tcg_const_i32(tgtmode); > + tcg_regno = tcg_const_i32(regno); > + gen_helper_mrs_banked(tcg_reg, cpu_env, tcg_tgtmode, tcg_regno); > + tcg_temp_free_i32(tcg_tgtmode); > + tcg_temp_free_i32(tcg_regno); > + store_reg(s, rn, tcg_reg); > + s->is_jmp = DISAS_UPDATE; > +} > + > /* Generate an old-style exception return. Marks pc as dead. */ > static void gen_exception_return(DisasContext *s, TCGv_i32 pc) > { > @@ -7950,7 +8139,26 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn) > sh = (insn >> 4) & 0xf; > rm = insn & 0xf; > switch (sh) { > - case 0x0: /* move program status register */ > + case 0x0: /* MSR, MRS */ > + if (insn & (1 << 9)) { > + /* MSR (banked) and MRS (banked) */ > + int sysm = extract32(insn, 16, 4) | > + (extract32(insn, 8, 1) << 4); > + int r = extract32(insn, 22, 1); > + > + if (op1 & 1) { > + /* MSR (banked) */ > + gen_msr_banked(s, r, sysm, rm); > + } else { > + /* MRS (banked) */ > + int rd = extract32(insn, 12, 4); > + > + gen_mrs_banked(s, r, sysm, rd); > + } > + break; > + } > + > + /* MSR, MRS (for PSRs) */ > if (op1 & 1) { > /* PSR = reg */ > tmp = load_reg(s, rm); > @@ -10055,6 +10263,18 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw > if (arm_dc_feature(s, ARM_FEATURE_M)) { > goto illegal_op; > } > + > + if (extract32(insn, 5, 1)) { > + /* MSR (banked) */ > + int sysm = extract32(insn, 8, 4) | > + (extract32(insn, 4, 1) << 4); > + int r = op & 1; > + > + gen_msr_banked(s, r, sysm, rm); > + break; > + } > + > + /* MSR (for PSRs) */ > tmp = load_reg(s, rn); > if (gen_set_psr(s, > msr_mask(s, (insn >> 8) & 0xf, op == 1), > @@ -10127,7 +10347,17 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw > tcg_gen_subi_i32(tmp, tmp, insn & 0xff); > gen_exception_return(s, tmp); > break; > - case 6: /* mrs cpsr. */ > + case 6: /* MRS */ > + if (extract32(insn, 5, 1)) { > + /* MRS (banked) */ > + int sysm = extract32(insn, 16, 4) | > + (extract32(insn, 4, 1) << 4); > + > + gen_mrs_banked(s, 0, sysm, rd); > + break; > + } > + > + /* mrs cpsr */ > tmp = tcg_temp_new_i32(); > if (arm_dc_feature(s, ARM_FEATURE_M)) { > addr = tcg_const_i32(insn & 0xff); > @@ -10138,7 +10368,17 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw > } > store_reg(s, rd, tmp); > break; > - case 7: /* mrs spsr. */ > + case 7: /* MRS */ > + if (extract32(insn, 5, 1)) { > + /* MRS (banked) */ > + int sysm = extract32(insn, 16, 4) | > + (extract32(insn, 4, 1) << 4); > + > + gen_mrs_banked(s, 1, sysm, rd); > + break; > + } > + > + /* mrs spsr. */ > /* Not accessible in user mode. */ > if (IS_USER(s) || arm_dc_feature(s, ARM_FEATURE_M)) { > goto illegal_op; > -- > 1.9.1 >
diff --git a/target-arm/helper.h b/target-arm/helper.h index ea13202..de3c644 100644 --- a/target-arm/helper.h +++ b/target-arm/helper.h @@ -76,6 +76,9 @@ DEF_HELPER_1(exception_return, void, env) DEF_HELPER_2(get_r13_banked, i32, env, i32) DEF_HELPER_3(set_r13_banked, void, env, i32, i32) +DEF_HELPER_3(mrs_banked, i32, env, i32, i32) +DEF_HELPER_4(msr_banked, void, env, i32, i32, i32) + DEF_HELPER_2(get_user_reg, i32, env, i32) DEF_HELPER_3(set_user_reg, void, env, i32, i32) diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c index 4881e34..a2afdd8 100644 --- a/target-arm/op_helper.c +++ b/target-arm/op_helper.c @@ -489,6 +489,126 @@ uint32_t HELPER(get_r13_banked)(CPUARMState *env, uint32_t mode) } } +static void msr_mrs_banked_exc_checks(CPUARMState *env, uint32_t tgtmode, + uint32_t regno) +{ + /* Raise an exception if the requested access is one of the UNPREDICTABLE + * cases; otherwise return. This broadly corresponds to the pseudocode + * BankedRegisterAccessValid() and SPSRAccessValid(), + * except that we have already handled some cases at translate time. + */ + int curmode = env->uncached_cpsr & CPSR_M; + + if (curmode == tgtmode) { + goto undef; + } + + if (tgtmode == ARM_CPU_MODE_USR) { + switch (regno) { + case 8 ... 12: + if (curmode != ARM_CPU_MODE_FIQ) { + goto undef; + } + break; + case 13: + if (curmode == ARM_CPU_MODE_SYS) { + goto undef; + } + break; + case 14: + if (curmode == ARM_CPU_MODE_HYP || curmode == ARM_CPU_MODE_SYS) { + goto undef; + } + break; + default: + break; + } + } + + if (tgtmode == ARM_CPU_MODE_HYP) { + switch (regno) { + case 17: /* ELR_Hyp */ + if (curmode != ARM_CPU_MODE_HYP && curmode != ARM_CPU_MODE_MON) { + goto undef; + } + break; + default: + if (curmode != ARM_CPU_MODE_MON) { + goto undef; + } + break; + } + } + + return; + +undef: + raise_exception(env, EXCP_UDEF, syn_uncategorized(), + exception_target_el(env)); +} + +void HELPER(msr_banked)(CPUARMState *env, uint32_t value, uint32_t tgtmode, + uint32_t regno) +{ + msr_mrs_banked_exc_checks(env, tgtmode, regno); + + switch (regno) { + case 16: /* SPSRs */ + env->banked_spsr[bank_number(tgtmode)] = value; + break; + case 17: /* ELR_Hyp */ + env->elr_el[2] = value; + break; + case 13: + env->banked_r13[bank_number(tgtmode)] = value; + break; + case 14: + env->banked_r14[bank_number(tgtmode)] = value; + break; + case 8 ... 12: + switch (tgtmode) { + case ARM_CPU_MODE_USR: + env->usr_regs[regno - 8] = value; + break; + case ARM_CPU_MODE_FIQ: + env->fiq_regs[regno - 8] = value; + break; + default: + g_assert_not_reached(); + } + break; + default: + g_assert_not_reached(); + } +} + +uint32_t HELPER(mrs_banked)(CPUARMState *env, uint32_t tgtmode, uint32_t regno) +{ + msr_mrs_banked_exc_checks(env, tgtmode, regno); + + switch (regno) { + case 16: /* SPSRs */ + return env->banked_spsr[bank_number(tgtmode)]; + case 17: /* ELR_Hyp */ + return env->elr_el[2]; + case 13: + return env->banked_r13[bank_number(tgtmode)]; + case 14: + return env->banked_r14[bank_number(tgtmode)]; + case 8 ... 12: + switch (tgtmode) { + case ARM_CPU_MODE_USR: + return env->usr_regs[regno - 8]; + case ARM_CPU_MODE_FIQ: + return env->fiq_regs[regno - 8]; + default: + g_assert_not_reached(); + } + default: + g_assert_not_reached(); + } +} + void HELPER(access_check_cp_reg)(CPUARMState *env, void *rip, uint32_t syndrome, uint32_t isread) { diff --git a/target-arm/translate.c b/target-arm/translate.c index 413f7de..a8dd490 100644 --- a/target-arm/translate.c +++ b/target-arm/translate.c @@ -4088,6 +4088,195 @@ static int gen_set_psr_im(DisasContext *s, uint32_t mask, int spsr, uint32_t val return gen_set_psr(s, mask, spsr, tmp); } +static bool msr_banked_access_decode(DisasContext *s, int r, int sysm, int rn, + int *tgtmode, int *regno) +{ + /* Decode the r and sysm fields of MSR/MRS banked accesses into + * the target mode and register number, and identify the various + * unpredictable cases. + * MSR (banked) and MRS (banked) are CONSTRAINED UNPREDICTABLE if: + * + executed in user mode + * + using R15 as the src/dest register + * + accessing an unimplemented register + * + accessing a register that's inaccessible at current PL/security state* + * + accessing a register that you could access with a different insn + * We choose to UNDEF in all these cases. + * Since we don't know which of the various AArch32 modes we are in + * we have to defer some checks to runtime. + * Accesses to Monitor mode registers from Secure EL1 (which implies + * that EL3 is AArch64) must trap to EL3. + * + * If the access checks fail this function will emit code to take + * an exception and return false. Otherwise it will return true, + * and set *tgtmode and *regno appropriately. + */ + int exc_target = default_exception_el(s); + + /* These instructions are present only in ARMv8, or in ARMv7 with the + * Virtualization Extensions. + */ + if (!arm_dc_feature(s, ARM_FEATURE_V8) && + !arm_dc_feature(s, ARM_FEATURE_EL2)) { + goto undef; + } + + if (IS_USER(s) || rn == 15) { + goto undef; + } + + /* The table in the v8 ARM ARM section F5.2.3 describes the encoding + * of registers into (r, sysm). + */ + if (r) { + /* SPSRs for other modes */ + switch (sysm) { + case 0xe: /* SPSR_fiq */ + *tgtmode = ARM_CPU_MODE_FIQ; + break; + case 0x10: /* SPSR_irq */ + *tgtmode = ARM_CPU_MODE_IRQ; + break; + case 0x12: /* SPSR_svc */ + *tgtmode = ARM_CPU_MODE_SVC; + break; + case 0x14: /* SPSR_abt */ + *tgtmode = ARM_CPU_MODE_ABT; + break; + case 0x16: /* SPSR_und */ + *tgtmode = ARM_CPU_MODE_UND; + break; + case 0x1c: /* SPSR_mon */ + *tgtmode = ARM_CPU_MODE_MON; + break; + case 0x1e: /* SPSR_hyp */ + *tgtmode = ARM_CPU_MODE_HYP; + break; + default: /* unallocated */ + goto undef; + } + /* We arbitrarily assign SPSR a register number of 16. */ + *regno = 16; + } else { + /* general purpose registers for other modes */ + switch (sysm) { + case 0x0 ... 0x6: /* 0b00xxx : r8_usr ... r14_usr */ + *tgtmode = ARM_CPU_MODE_USR; + *regno = sysm + 8; + break; + case 0x8 ... 0xe: /* 0b01xxx : r8_fiq ... r14_fiq */ + *tgtmode = ARM_CPU_MODE_FIQ; + *regno = sysm; + break; + case 0x10 ... 0x11: /* 0b1000x : r14_irq, r13_irq */ + *tgtmode = ARM_CPU_MODE_IRQ; + *regno = sysm & 1 ? 13 : 14; + break; + case 0x12 ... 0x13: /* 0b1001x : r14_svc, r13_svc */ + *tgtmode = ARM_CPU_MODE_SVC; + *regno = sysm & 1 ? 13 : 14; + break; + case 0x14 ... 0x15: /* 0b1010x : r14_abt, r13_abt */ + *tgtmode = ARM_CPU_MODE_ABT; + *regno = sysm & 1 ? 13 : 14; + break; + case 0x16 ... 0x17: /* 0b1011x : r14_und, r13_und */ + *tgtmode = ARM_CPU_MODE_UND; + *regno = sysm & 1 ? 13 : 14; + break; + case 0x1c ... 0x1d: /* 0b1110x : r14_mon, r13_mon */ + *tgtmode = ARM_CPU_MODE_MON; + *regno = sysm & 1 ? 13 : 14; + break; + case 0x1e ... 0x1f: /* 0b1111x : elr_hyp, r13_hyp */ + *tgtmode = ARM_CPU_MODE_HYP; + /* Arbitrarily pick 17 for ELR_Hyp (which is not a banked LR!) */ + *regno = sysm & 1 ? 13 : 17; + break; + default: /* unallocated */ + goto undef; + } + } + + /* Catch the 'accessing inaccessible register' cases we can detect + * at translate time. + */ + switch (*tgtmode) { + case ARM_CPU_MODE_MON: + if (!arm_dc_feature(s, ARM_FEATURE_EL3) || s->ns) { + goto undef; + } + if (s->current_el == 1) { + /* If we're in Secure EL1 (which implies that EL3 is AArch64) + * then accesses to Mon registers trap to EL3 + */ + exc_target = 3; + goto undef; + } + break; + case ARM_CPU_MODE_HYP: + /* Note that we can forbid accesses from EL2 here because they + * must be from Hyp mode itself + */ + if (!arm_dc_feature(s, ARM_FEATURE_EL2) || s->current_el < 3) { + goto undef; + } + break; + default: + break; + } + + return true; + +undef: + /* If we get here then some access check did not pass */ + gen_exception_insn(s, 4, EXCP_UDEF, syn_uncategorized(), exc_target); + return false; +} + +static void gen_msr_banked(DisasContext *s, int r, int sysm, int rn) +{ + TCGv_i32 tcg_reg, tcg_tgtmode, tcg_regno; + int tgtmode, regno; + + if (!msr_banked_access_decode(s, r, sysm, rn, &tgtmode, ®no)) { + return; + } + + /* Sync state because msr_banked() can raise exceptions */ + gen_set_condexec(s); + gen_set_pc_im(s, s->pc - 4); + tcg_reg = load_reg(s, rn); + tcg_tgtmode = tcg_const_i32(tgtmode); + tcg_regno = tcg_const_i32(regno); + gen_helper_msr_banked(cpu_env, tcg_reg, tcg_tgtmode, tcg_regno); + tcg_temp_free_i32(tcg_tgtmode); + tcg_temp_free_i32(tcg_regno); + tcg_temp_free_i32(tcg_reg); + s->is_jmp = DISAS_UPDATE; +} + +static void gen_mrs_banked(DisasContext *s, int r, int sysm, int rn) +{ + TCGv_i32 tcg_reg, tcg_tgtmode, tcg_regno; + int tgtmode, regno; + + if (!msr_banked_access_decode(s, r, sysm, rn, &tgtmode, ®no)) { + return; + } + + /* Sync state because mrs_banked() can raise exceptions */ + gen_set_condexec(s); + gen_set_pc_im(s, s->pc - 4); + tcg_reg = tcg_temp_new_i32(); + tcg_tgtmode = tcg_const_i32(tgtmode); + tcg_regno = tcg_const_i32(regno); + gen_helper_mrs_banked(tcg_reg, cpu_env, tcg_tgtmode, tcg_regno); + tcg_temp_free_i32(tcg_tgtmode); + tcg_temp_free_i32(tcg_regno); + store_reg(s, rn, tcg_reg); + s->is_jmp = DISAS_UPDATE; +} + /* Generate an old-style exception return. Marks pc as dead. */ static void gen_exception_return(DisasContext *s, TCGv_i32 pc) { @@ -7950,7 +8139,26 @@ static void disas_arm_insn(DisasContext *s, unsigned int insn) sh = (insn >> 4) & 0xf; rm = insn & 0xf; switch (sh) { - case 0x0: /* move program status register */ + case 0x0: /* MSR, MRS */ + if (insn & (1 << 9)) { + /* MSR (banked) and MRS (banked) */ + int sysm = extract32(insn, 16, 4) | + (extract32(insn, 8, 1) << 4); + int r = extract32(insn, 22, 1); + + if (op1 & 1) { + /* MSR (banked) */ + gen_msr_banked(s, r, sysm, rm); + } else { + /* MRS (banked) */ + int rd = extract32(insn, 12, 4); + + gen_mrs_banked(s, r, sysm, rd); + } + break; + } + + /* MSR, MRS (for PSRs) */ if (op1 & 1) { /* PSR = reg */ tmp = load_reg(s, rm); @@ -10055,6 +10263,18 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw if (arm_dc_feature(s, ARM_FEATURE_M)) { goto illegal_op; } + + if (extract32(insn, 5, 1)) { + /* MSR (banked) */ + int sysm = extract32(insn, 8, 4) | + (extract32(insn, 4, 1) << 4); + int r = op & 1; + + gen_msr_banked(s, r, sysm, rm); + break; + } + + /* MSR (for PSRs) */ tmp = load_reg(s, rn); if (gen_set_psr(s, msr_mask(s, (insn >> 8) & 0xf, op == 1), @@ -10127,7 +10347,17 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw tcg_gen_subi_i32(tmp, tmp, insn & 0xff); gen_exception_return(s, tmp); break; - case 6: /* mrs cpsr. */ + case 6: /* MRS */ + if (extract32(insn, 5, 1)) { + /* MRS (banked) */ + int sysm = extract32(insn, 16, 4) | + (extract32(insn, 4, 1) << 4); + + gen_mrs_banked(s, 0, sysm, rd); + break; + } + + /* mrs cpsr */ tmp = tcg_temp_new_i32(); if (arm_dc_feature(s, ARM_FEATURE_M)) { addr = tcg_const_i32(insn & 0xff); @@ -10138,7 +10368,17 @@ static int disas_thumb2_insn(CPUARMState *env, DisasContext *s, uint16_t insn_hw } store_reg(s, rd, tmp); break; - case 7: /* mrs spsr. */ + case 7: /* MRS */ + if (extract32(insn, 5, 1)) { + /* MRS (banked) */ + int sysm = extract32(insn, 16, 4) | + (extract32(insn, 4, 1) << 4); + + gen_mrs_banked(s, 1, sysm, rd); + break; + } + + /* mrs spsr. */ /* Not accessible in user mode. */ if (IS_USER(s) || arm_dc_feature(s, ARM_FEATURE_M)) { goto illegal_op;
Starting with the ARMv7 Virtualization Extensions, the A32 and T32 instruction sets provide instructions "MSR (banked)" and "MRS (banked)" which can be used to access registers for a mode other than the current one: * R<m>_<mode> * ELR_hyp * SPSR_<mode> Implement the missing instructions. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- We don't support EL2 yet, but you can get at these on a v8 CPU in 32-bit EL1 if EL3 is enabled. Obviously there's not going to be much 32-bit EL1 code out there that uses the insns though, as it wouldn't work on v7 if it did... target-arm/helper.h | 3 + target-arm/op_helper.c | 120 ++++++++++++++++++++++++ target-arm/translate.c | 246 ++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 366 insertions(+), 3 deletions(-)