Add both SVE exception state and vector length.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 target/arm/cpu.h           |  8 ++++++++
 target/arm/translate.h     |  2 ++
 target/arm/helper.c        | 25 ++++++++++++++++++++++++-
 target/arm/translate-a64.c |  2 ++
 4 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 17955ad3ef..a311d4e327 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -2648,6 +2648,10 @@ static inline bool arm_cpu_data_is_big_endian(CPUARMState *env)
 #define ARM_TBFLAG_TBI0_MASK (0x1ull << ARM_TBFLAG_TBI0_SHIFT)
 #define ARM_TBFLAG_TBI1_SHIFT 1        /* TBI1 for EL0/1  */
 #define ARM_TBFLAG_TBI1_MASK (0x1ull << ARM_TBFLAG_TBI1_SHIFT)
+#define ARM_TBFLAG_SVEEXC_EL_SHIFT  2
+#define ARM_TBFLAG_SVEEXC_EL_MASK   (0x3 << ARM_TBFLAG_SVEEXC_EL_SHIFT)
+#define ARM_TBFLAG_ZCR_LEN_SHIFT    4
+#define ARM_TBFLAG_ZCR_LEN_MASK     (0xf << ARM_TBFLAG_ZCR_LEN_SHIFT)
 
 /* some convenience accessor macros */
 #define ARM_TBFLAG_AARCH64_STATE(F) \
@@ -2684,6 +2688,10 @@ static inline bool arm_cpu_data_is_big_endian(CPUARMState *env)
     (((F) & ARM_TBFLAG_TBI0_MASK) >> ARM_TBFLAG_TBI0_SHIFT)
 #define ARM_TBFLAG_TBI1(F) \
     (((F) & ARM_TBFLAG_TBI1_MASK) >> ARM_TBFLAG_TBI1_SHIFT)
+#define ARM_TBFLAG_SVEEXC_EL(F) \
+    (((F) & ARM_TBFLAG_SVEEXC_EL_MASK) >> ARM_TBFLAG_SVEEXC_EL_SHIFT)
+#define ARM_TBFLAG_ZCR_LEN(F) \
+    (((F) & ARM_TBFLAG_ZCR_LEN_MASK) >> ARM_TBFLAG_ZCR_LEN_SHIFT)
 
 static inline bool bswap_code(bool sctlr_b)
 {
diff --git a/target/arm/translate.h b/target/arm/translate.h
index 3f4df91e5e..c47febf99d 100644
--- a/target/arm/translate.h
+++ b/target/arm/translate.h
@@ -29,6 +29,8 @@ typedef struct DisasContext {
     bool tbi1;         /* TBI1 for EL0/1, not used for EL2/3 */
     bool ns;        /* Use non-secure CPREG bank on access */
     int fp_excp_el; /* FP exception EL or 0 if enabled */
+    int sve_excp_el; /* SVE exception EL or 0 if enabled */
+    int sve_len;     /* SVE vector length in bytes */
     /* Flag indicating that exceptions from secure mode are routed to EL3. */
     bool secure_routed_to_el3;
     bool vfp_enabled; /* FP enabled via FPSCR.EN */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index db67e8ac72..d46d3622fc 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -11823,14 +11823,37 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
                           target_ulong *cs_base, uint32_t *pflags)
 {
     ARMMMUIdx mmu_idx = core_to_arm_mmu_idx(env, cpu_mmu_index(env, false));
+    int fp_el = fp_exception_el(env);
     uint32_t flags;
 
     if (is_a64(env)) {
+        int sve_el = sve_exception_el(env);
+        uint32_t zcr_len;
+
         *pc = env->pc;
         flags = ARM_TBFLAG_AARCH64_STATE_MASK;
         /* Get control bits for tagged addresses */
         flags |= (arm_regime_tbi0(env, mmu_idx) << ARM_TBFLAG_TBI0_SHIFT);
         flags |= (arm_regime_tbi1(env, mmu_idx) << ARM_TBFLAG_TBI1_SHIFT);
+        flags |= sve_el << ARM_TBFLAG_SVEEXC_EL_SHIFT;
+
+        /* If SVE is disabled, but FP is enabled,
+           then the effective len is 0.  */
+        if (sve_el != 0 && fp_el == 0) {
+            zcr_len = 0;
+        } else {
+            int current_el = arm_current_el(env);
+
+            zcr_len = env->vfp.zcr_el[current_el <= 1 ? 1 : current_el];
+            zcr_len &= 0xf;
+            if (current_el < 2 && arm_feature(env, ARM_FEATURE_EL2)) {
+                zcr_len = MIN(zcr_len, 0xf & (uint32_t)env->vfp.zcr_el[2]);
+            }
+            if (current_el < 3 && arm_feature(env, ARM_FEATURE_EL3)) {
+                zcr_len = MIN(zcr_len, 0xf & (uint32_t)env->vfp.zcr_el[3]);
+            }
+        }
+        flags |= zcr_len << ARM_TBFLAG_ZCR_LEN_SHIFT;
     } else {
         *pc = env->regs[15];
         flags = (env->thumb << ARM_TBFLAG_THUMB_SHIFT)
@@ -11873,7 +11896,7 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
     if (arm_cpu_data_is_big_endian(env)) {
         flags |= ARM_TBFLAG_BE_DATA_MASK;
     }
-    flags |= fp_exception_el(env) << ARM_TBFLAG_FPEXC_EL_SHIFT;
+    flags |= fp_el << ARM_TBFLAG_FPEXC_EL_SHIFT;
 
     if (arm_v7m_is_handler_mode(env)) {
         flags |= ARM_TBFLAG_HANDLER_MASK;
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index 10eef870fe..4c1eca7062 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -11263,6 +11263,8 @@ static int aarch64_tr_init_disas_context(DisasContextBase *dcbase,
     dc->user = (dc->current_el == 0);
 #endif
     dc->fp_excp_el = ARM_TBFLAG_FPEXC_EL(dc->base.tb->flags);
+    dc->sve_excp_el = ARM_TBFLAG_SVEEXC_EL(dc->base.tb->flags);
+    dc->sve_len = (ARM_TBFLAG_ZCR_LEN(dc->base.tb->flags) + 1) * 16;
     dc->vec_len = 0;
     dc->vec_stride = 0;
     dc->cp_regs = arm_cpu->cp_regs;
-- 
2.14.3

On 23 January 2018 at 03:53, Richard Henderson
<richard.henderson@linaro.org> wrote:
> Add both SVE exception state and vector length.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
> index 10eef870fe..4c1eca7062 100644
> --- a/target/arm/translate-a64.c
> +++ b/target/arm/translate-a64.c
> @@ -11263,6 +11263,8 @@ static int aarch64_tr_init_disas_context(DisasContextBase *dcbase,
>      dc->user = (dc->current_el == 0);
>  #endif
>      dc->fp_excp_el = ARM_TBFLAG_FPEXC_EL(dc->base.tb->flags);
> +    dc->sve_excp_el = ARM_TBFLAG_SVEEXC_EL(dc->base.tb->flags);
> +    dc->sve_len = (ARM_TBFLAG_ZCR_LEN(dc->base.tb->flags) + 1) * 16;

You've carefully arranged that the sve_excp checks are a superset
of the fp_excp checks, which means that we get the correct
exception prioritization by always doing the sve_excp check first
and then the fp_excp check second, without having to look at
whether fp_excp_el or sve_excp_el is larger to see which should
take precedence. We could
  assert(dc->sve_excp_el <= dc->fp_excp_el);
and perhaps have a comment noting why this is useful...

Otherwise
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM

On 01/29/2018 10:01 AM, Peter Maydell wrote:
> On 23 January 2018 at 03:53, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>> Add both SVE exception state and vector length.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> 
>> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
>> index 10eef870fe..4c1eca7062 100644
>> --- a/target/arm/translate-a64.c
>> +++ b/target/arm/translate-a64.c
>> @@ -11263,6 +11263,8 @@ static int aarch64_tr_init_disas_context(DisasContextBase *dcbase,
>>      dc->user = (dc->current_el == 0);
>>  #endif
>>      dc->fp_excp_el = ARM_TBFLAG_FPEXC_EL(dc->base.tb->flags);
>> +    dc->sve_excp_el = ARM_TBFLAG_SVEEXC_EL(dc->base.tb->flags);
>> +    dc->sve_len = (ARM_TBFLAG_ZCR_LEN(dc->base.tb->flags) + 1) * 16;
> 
> You've carefully arranged that the sve_excp checks are a superset
> of the fp_excp checks, which means that we get the correct
> exception prioritization by always doing the sve_excp check first
> and then the fp_excp check second, without having to look at
> whether fp_excp_el or sve_excp_el is larger to see which should
> take precedence. We could
>   assert(dc->sve_excp_el <= dc->fp_excp_el);
> and perhaps have a comment noting why this is useful...

Sort of, I suppose.  Modulo the fact that "enabled" is zero,
so sve disabled &  fp enabled means sve_el > fp_el.

But you're right that to some extent I'm doing too much work
replicating the fp exception check.


r~