Xtensa internal fields are opaque, only accessible by
the Xtensa libisa. Implement xtensa_isa_is_big_endian()
to get vCPU endianness. This should be implemented in
libisa, not QEMU, but I couldn't figure out where to
contribute this.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/hw/xtensa/xtensa-isa.h | 1 +
 target/xtensa/xtensa-isa.c     | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/include/hw/xtensa/xtensa-isa.h b/include/hw/xtensa/xtensa-isa.h
index a289531bdc8..1cb8e6ccb66 100644
--- a/include/hw/xtensa/xtensa-isa.h
+++ b/include/hw/xtensa/xtensa-isa.h
@@ -829,6 +829,7 @@ const char *xtensa_funcUnit_name(xtensa_isa isa, xtensa_funcUnit fun);
 
 int xtensa_funcUnit_num_copies(xtensa_isa isa, xtensa_funcUnit fun);
 
+bool xtensa_isa_is_big_endian(xtensa_isa isa);
 
 #ifdef __cplusplus
 }
diff --git a/target/xtensa/xtensa-isa.c b/target/xtensa/xtensa-isa.c
index 630b4f9da1b..36eb4bcf3d4 100644
--- a/target/xtensa/xtensa-isa.c
+++ b/target/xtensa/xtensa-isa.c
@@ -1741,3 +1741,10 @@ int xtensa_funcUnit_num_copies(xtensa_isa isa, xtensa_funcUnit fun)
     CHECK_FUNCUNIT(intisa, fun, XTENSA_UNDEFINED);
     return intisa->funcUnits[fun].num_copies;
 }
+
+bool xtensa_isa_is_big_endian(xtensa_isa isa)
+{
+    xtensa_isa_internal *intisa = (xtensa_isa_internal *)isa;
+
+    return intisa->is_big_endian;
+}
-- 
2.45.2

On Thu, Dec 5, 2024 at 3:24 PM Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
> Xtensa internal fields are opaque, only accessible by
> the Xtensa libisa. Implement xtensa_isa_is_big_endian()
> to get vCPU endianness. This should be implemented in
> libisa, not QEMU, but I couldn't figure out where to
> contribute this.

This is a beautified version of what xtensa has in binutils, but
binutils is also
just another user of that internal Tensilica library. Perhaps I should make
an artificial "upstream" for this library just to track this kind of changes.
Let me look at it.

> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>  include/hw/xtensa/xtensa-isa.h | 1 +
>  target/xtensa/xtensa-isa.c     | 7 +++++++
>  2 files changed, 8 insertions(+)
>
> diff --git a/include/hw/xtensa/xtensa-isa.h b/include/hw/xtensa/xtensa-isa.h
> index a289531bdc8..1cb8e6ccb66 100644
> --- a/include/hw/xtensa/xtensa-isa.h
> +++ b/include/hw/xtensa/xtensa-isa.h
> @@ -829,6 +829,7 @@ const char *xtensa_funcUnit_name(xtensa_isa isa, xtensa_funcUnit fun);
>
>  int xtensa_funcUnit_num_copies(xtensa_isa isa, xtensa_funcUnit fun);
>
> +bool xtensa_isa_is_big_endian(xtensa_isa isa);

This file doesn't include stdbool.h and other boolean functions in it
(e.g. xtensa_opcode_is_branch()) return int. I'd suggest sticking with
that. With that change:

Acked-by: Max Filippov <jcmvbkbc@gmail.com>

>  #ifdef __cplusplus
>  }
> diff --git a/target/xtensa/xtensa-isa.c b/target/xtensa/xtensa-isa.c
> index 630b4f9da1b..36eb4bcf3d4 100644
> --- a/target/xtensa/xtensa-isa.c
> +++ b/target/xtensa/xtensa-isa.c
> @@ -1741,3 +1741,10 @@ int xtensa_funcUnit_num_copies(xtensa_isa isa, xtensa_funcUnit fun)
>      CHECK_FUNCUNIT(intisa, fun, XTENSA_UNDEFINED);
>      return intisa->funcUnits[fun].num_copies;
>  }
> +
> +bool xtensa_isa_is_big_endian(xtensa_isa isa)
> +{
> +    xtensa_isa_internal *intisa = (xtensa_isa_internal *)isa;
> +
> +    return intisa->is_big_endian;
> +}

-- 
Thanks.
-- Max

Hi Max,

On 6/12/24 13:35, Max Filippov wrote:
> On Thu, Dec 5, 2024 at 3:24 PM Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>> Xtensa internal fields are opaque, only accessible by
>> the Xtensa libisa. Implement xtensa_isa_is_big_endian()
>> to get vCPU endianness. This should be implemented in
>> libisa, not QEMU, but I couldn't figure out where to
>> contribute this.
> 
> This is a beautified version of what xtensa has in binutils, but
> binutils is also
> just another user of that internal Tensilica library. Perhaps I should make
> an artificial "upstream" for this library just to track this kind of changes.
> Let me look at it.

Could you add this method to the Tensilica library?

> 
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>> ---
>>   include/hw/xtensa/xtensa-isa.h | 1 +
>>   target/xtensa/xtensa-isa.c     | 7 +++++++
>>   2 files changed, 8 insertions(+)
>>
>> diff --git a/include/hw/xtensa/xtensa-isa.h b/include/hw/xtensa/xtensa-isa.h
>> index a289531bdc8..1cb8e6ccb66 100644
>> --- a/include/hw/xtensa/xtensa-isa.h
>> +++ b/include/hw/xtensa/xtensa-isa.h
>> @@ -829,6 +829,7 @@ const char *xtensa_funcUnit_name(xtensa_isa isa, xtensa_funcUnit fun);
>>
>>   int xtensa_funcUnit_num_copies(xtensa_isa isa, xtensa_funcUnit fun);
>>
>> +bool xtensa_isa_is_big_endian(xtensa_isa isa);
> 
> This file doesn't include stdbool.h and other boolean functions in it
> (e.g. xtensa_opcode_is_branch()) return int. I'd suggest sticking with
> that. With that change:
> 
> Acked-by: Max Filippov <jcmvbkbc@gmail.com>
> 
>>   #ifdef __cplusplus
>>   }
>> diff --git a/target/xtensa/xtensa-isa.c b/target/xtensa/xtensa-isa.c
>> index 630b4f9da1b..36eb4bcf3d4 100644
>> --- a/target/xtensa/xtensa-isa.c
>> +++ b/target/xtensa/xtensa-isa.c
>> @@ -1741,3 +1741,10 @@ int xtensa_funcUnit_num_copies(xtensa_isa isa, xtensa_funcUnit fun)
>>       CHECK_FUNCUNIT(intisa, fun, XTENSA_UNDEFINED);
>>       return intisa->funcUnits[fun].num_copies;
>>   }
>> +
>> +bool xtensa_isa_is_big_endian(xtensa_isa isa)
>> +{
>> +    xtensa_isa_internal *intisa = (xtensa_isa_internal *)isa;
>> +
>> +    return intisa->is_big_endian;
>> +}
>