[2/4] target/arm: Update MSR access to UAO

Message ID 20191203234244.9124-3-richard.henderson@linaro.org
State New
Headers show
Series
  • target/arm: Implement ARMv8.2-UAO
Related show

Commit Message

Richard Henderson Dec. 3, 2019, 11:42 p.m.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 target/arm/cpu.h           |  6 ++++++
 target/arm/helper.c        | 21 +++++++++++++++++++++
 target/arm/translate-a64.c | 14 ++++++++++++++
 3 files changed, 41 insertions(+)

-- 
2.17.1

Comments

Peter Maydell Dec. 6, 2019, 6:30 p.m. | #1
On Tue, 3 Dec 2019 at 23:42, Richard Henderson
<richard.henderson@linaro.org> wrote:
>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  target/arm/cpu.h           |  6 ++++++

>  target/arm/helper.c        | 21 +++++++++++++++++++++

>  target/arm/translate-a64.c | 14 ++++++++++++++

>  3 files changed, 41 insertions(+)

>

> diff --git a/target/arm/cpu.h b/target/arm/cpu.h

> index cdf6caf869..dd284ba5c7 100644

> --- a/target/arm/cpu.h

> +++ b/target/arm/cpu.h

> @@ -1228,6 +1228,7 @@ void pmu_init(ARMCPU *cpu);

>  #define PSTATE_IL (1U << 20)

>  #define PSTATE_SS (1U << 21)

>  #define PSTATE_PAN (1U << 22)

> +#define PSTATE_UAO (1U << 23)

>  #define PSTATE_V (1U << 28)

>  #define PSTATE_C (1U << 29)

>  #define PSTATE_Z (1U << 30)

> @@ -3598,6 +3599,11 @@ static inline bool isar_feature_aa64_ats1e1(const ARMISARegisters *id)

>      return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, PAN) >= 2;

>  }

>

> +static inline bool isar_feature_aa64_uao(const ARMISARegisters *id)

> +{

> +    return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, UAO) != 0;

> +}

> +

>  static inline bool isar_feature_aa64_bti(const ARMISARegisters *id)

>  {

>      return FIELD_EX64(id->id_aa64pfr1, ID_AA64PFR1, BT) != 0;

> diff --git a/target/arm/helper.c b/target/arm/helper.c

> index 70f2db5447..8941a6c10f 100644

> --- a/target/arm/helper.c

> +++ b/target/arm/helper.c

> @@ -4131,6 +4131,17 @@ static void aa64_pan_write(CPUARMState *env, const ARMCPRegInfo *ri,

>      env->pstate = (env->pstate & ~PSTATE_PAN) | (value & PSTATE_PAN);

>  }

>

> +static uint64_t aa64_uao_read(CPUARMState *env, const ARMCPRegInfo *ri)

> +{

> +    return env->pstate & PSTATE_UAO;

> +}

> +

> +static void aa64_uao_write(CPUARMState *env, const ARMCPRegInfo *ri,

> +                           uint64_t value)

> +{

> +    env->pstate = (env->pstate & ~PSTATE_UAO) | (value & PSTATE_UAO);

> +}

> +

>  static CPAccessResult aa64_cacheop_access(CPUARMState *env,

>                                            const ARMCPRegInfo *ri,

>                                            bool isread)

> @@ -7464,6 +7475,16 @@ void register_cp_regs_for_features(ARMCPU *cpu)

>          define_arm_cp_regs(cpu, ats1cp_reginfo);

>      }

>  #endif

> +    if (cpu_isar_feature(aa64_uao, cpu)) {

> +        static const ARMCPRegInfo uao_reginfo[] = {

> +            { .name = "UAO", .state = ARM_CP_STATE_AA64,

> +              .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 2, .opc2 = 4,

> +              .type = ARM_CP_NO_RAW, .access = PL1_RW,

> +              .readfn = aa64_uao_read, .writefn = aa64_uao_write, },

> +            REGINFO_SENTINEL

> +        };


This could just be a file-scope global, right?
Also, you can just use define_one_arm_cp_reg() rather
than having a list with one entry. (cf zcr_el1_reginfo).

> +        define_arm_cp_regs(cpu, uao_reginfo);

> +    }

>

>      if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {

>          static const ARMCPRegInfo vhe_reginfo[] = {

> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c

> index 7f5a68106b..2b6846ef01 100644

> --- a/target/arm/translate-a64.c

> +++ b/target/arm/translate-a64.c

> @@ -1601,6 +1601,20 @@ static void handle_msr_i(DisasContext *s, uint32_t insn,

>          s->base.is_jmp = DISAS_NEXT;

>          break;

>

> +    case 0x03: /* UAO */

> +        if (!dc_isar_feature(aa64_uao, s) || s->current_el == 0) {

> +            goto do_unallocated;

> +        }

> +        if (crm & 1) {

> +            set_pstate_bits(PSTATE_UAO);

> +        } else {

> +            clear_pstate_bits(PSTATE_UAO);

> +        }

> +        t1 = tcg_const_i32(s->current_el);

> +        gen_helper_rebuild_hflags_a64(cpu_env, t1);

> +        tcg_temp_free_i32(t1);

> +        break;


Do we also need to end the TB since we've messed with
the hflags, or is some bit of code not in the patch
context handling that?

> +

>      case 0x04: /* PAN */

>          if (!dc_isar_feature(aa64_pan, s) || s->current_el == 0) {

>              goto do_unallocated;

> --

> 2.17.1


Does the "on exception entry PSTATE.UAO is zeroed" behaviour
fall out automatically for us? How about "on exception entry
from aarch32 to aarch64 SPSR_ELx.UAO is set to zero" ?

I think we may also want a minor code change so that an exception
return from aarch64 to aarch32 doesn't copy a bogus SPSR UAO==1
into the pstate/cpsr.

thanks
-- PMM
Richard Henderson Dec. 6, 2019, 7 p.m. | #2
On 12/6/19 10:30 AM, Peter Maydell wrote:
>> +    if (cpu_isar_feature(aa64_uao, cpu)) {

>> +        static const ARMCPRegInfo uao_reginfo[] = {

>> +            { .name = "UAO", .state = ARM_CP_STATE_AA64,

>> +              .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 2, .opc2 = 4,

>> +              .type = ARM_CP_NO_RAW, .access = PL1_RW,

>> +              .readfn = aa64_uao_read, .writefn = aa64_uao_write, },

>> +            REGINFO_SENTINEL

>> +        };

> 

> This could just be a file-scope global, right?

> Also, you can just use define_one_arm_cp_reg() rather

> than having a list with one entry. (cf zcr_el1_reginfo).


Can do.

>> +    case 0x03: /* UAO */

>> +        if (!dc_isar_feature(aa64_uao, s) || s->current_el == 0) {

>> +            goto do_unallocated;

>> +        }

>> +        if (crm & 1) {

>> +            set_pstate_bits(PSTATE_UAO);

>> +        } else {

>> +            clear_pstate_bits(PSTATE_UAO);

>> +        }

>> +        t1 = tcg_const_i32(s->current_el);

>> +        gen_helper_rebuild_hflags_a64(cpu_env, t1);

>> +        tcg_temp_free_i32(t1);

>> +        break;

> 

> Do we also need to end the TB since we've messed with

> the hflags, or is some bit of code not in the patch

> context handling that?


Outside the patch context, at the start of the function, we default to ending
the TB.

> Does the "on exception entry PSTATE.UAO is zeroed" behaviour

> fall out automatically for us? How about "on exception entry

> from aarch32 to aarch64 SPSR_ELx.UAO is set to zero" ?


Yes to both -- new_mode (perhaps better renamed as new_pstate) is initialized
as 0 + stuff required to be non-zero.  Thus PAN required special handling but
UAO does not.

> I think we may also want a minor code change so that an exception

> return from aarch64 to aarch32 doesn't copy a bogus SPSR UAO==1

> into the pstate/cpsr.


Ah, good catch.


r~

Patch

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index cdf6caf869..dd284ba5c7 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1228,6 +1228,7 @@  void pmu_init(ARMCPU *cpu);
 #define PSTATE_IL (1U << 20)
 #define PSTATE_SS (1U << 21)
 #define PSTATE_PAN (1U << 22)
+#define PSTATE_UAO (1U << 23)
 #define PSTATE_V (1U << 28)
 #define PSTATE_C (1U << 29)
 #define PSTATE_Z (1U << 30)
@@ -3598,6 +3599,11 @@  static inline bool isar_feature_aa64_ats1e1(const ARMISARegisters *id)
     return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, PAN) >= 2;
 }
 
+static inline bool isar_feature_aa64_uao(const ARMISARegisters *id)
+{
+    return FIELD_EX64(id->id_aa64mmfr2, ID_AA64MMFR2, UAO) != 0;
+}
+
 static inline bool isar_feature_aa64_bti(const ARMISARegisters *id)
 {
     return FIELD_EX64(id->id_aa64pfr1, ID_AA64PFR1, BT) != 0;
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 70f2db5447..8941a6c10f 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -4131,6 +4131,17 @@  static void aa64_pan_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->pstate = (env->pstate & ~PSTATE_PAN) | (value & PSTATE_PAN);
 }
 
+static uint64_t aa64_uao_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    return env->pstate & PSTATE_UAO;
+}
+
+static void aa64_uao_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                           uint64_t value)
+{
+    env->pstate = (env->pstate & ~PSTATE_UAO) | (value & PSTATE_UAO);
+}
+
 static CPAccessResult aa64_cacheop_access(CPUARMState *env,
                                           const ARMCPRegInfo *ri,
                                           bool isread)
@@ -7464,6 +7475,16 @@  void register_cp_regs_for_features(ARMCPU *cpu)
         define_arm_cp_regs(cpu, ats1cp_reginfo);
     }
 #endif
+    if (cpu_isar_feature(aa64_uao, cpu)) {
+        static const ARMCPRegInfo uao_reginfo[] = {
+            { .name = "UAO", .state = ARM_CP_STATE_AA64,
+              .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 2, .opc2 = 4,
+              .type = ARM_CP_NO_RAW, .access = PL1_RW,
+              .readfn = aa64_uao_read, .writefn = aa64_uao_write, },
+            REGINFO_SENTINEL
+        };
+        define_arm_cp_regs(cpu, uao_reginfo);
+    }
 
     if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {
         static const ARMCPRegInfo vhe_reginfo[] = {
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 7f5a68106b..2b6846ef01 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -1601,6 +1601,20 @@  static void handle_msr_i(DisasContext *s, uint32_t insn,
         s->base.is_jmp = DISAS_NEXT;
         break;
 
+    case 0x03: /* UAO */
+        if (!dc_isar_feature(aa64_uao, s) || s->current_el == 0) {
+            goto do_unallocated;
+        }
+        if (crm & 1) {
+            set_pstate_bits(PSTATE_UAO);
+        } else {
+            clear_pstate_bits(PSTATE_UAO);
+        }
+        t1 = tcg_const_i32(s->current_el);
+        gen_helper_rebuild_hflags_a64(cpu_env, t1);
+        tcg_temp_free_i32(t1);
+        break;
+
     case 0x04: /* PAN */
         if (!dc_isar_feature(aa64_pan, s) || s->current_el == 0) {
             goto do_unallocated;