Return output buffer and size via output pointer arguments,
rather than returning size via tcg_ctx->code_gen_buffer_size.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/region.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/tcg/region.c b/tcg/region.c
index b44246e1aa..652f328d2c 100644
--- a/tcg/region.c
+++ b/tcg/region.c
@@ -467,7 +467,8 @@ static inline bool cross_256mb(void *addr, size_t size)
 /* We weren't able to allocate a buffer without crossing that boundary,
    so make do with the larger portion of the buffer that doesn't cross.
    Returns the new base of the buffer, and adjusts code_gen_buffer_size.  */
-static inline void *split_cross_256mb(void *buf1, size_t size1)
+static inline void split_cross_256mb(void **obuf, size_t *osize,
+                                     void *buf1, size_t size1)
 {
     void *buf2 = (void *)(((uintptr_t)buf1 + size1) & ~0x0ffffffful);
     size_t size2 = buf1 + size1 - buf2;
@@ -478,8 +479,8 @@ static inline void *split_cross_256mb(void *buf1, size_t size1)
         buf1 = buf2;
     }
 
-    tcg_ctx->code_gen_buffer_size = size1;
-    return buf1;
+    *obuf = buf1;
+    *osize = size1;
 }
 #endif
 
@@ -509,12 +510,10 @@ static bool alloc_code_gen_buffer(size_t tb_size, int splitwx, Error **errp)
     if (size > tb_size) {
         size = QEMU_ALIGN_DOWN(tb_size, qemu_real_host_page_size);
     }
-    tcg_ctx->code_gen_buffer_size = size;
 
 #ifdef __mips__
     if (cross_256mb(buf, size)) {
-        buf = split_cross_256mb(buf, size);
-        size = tcg_ctx->code_gen_buffer_size;
+        split_cross_256mb(&buf, &size, buf, size);
     }
 #endif
 
@@ -525,6 +524,7 @@ static bool alloc_code_gen_buffer(size_t tb_size, int splitwx, Error **errp)
     qemu_madvise(buf, size, QEMU_MADV_HUGEPAGE);
 
     tcg_ctx->code_gen_buffer = buf;
+    tcg_ctx->code_gen_buffer_size = size;
     return true;
 }
 #elif defined(_WIN32)
@@ -583,8 +583,7 @@ static bool alloc_code_gen_buffer_anon(size_t size, int prot,
             /* fallthru */
         default:
             /* Split the original buffer.  Free the smaller half.  */
-            buf2 = split_cross_256mb(buf, size);
-            size2 = tcg_ctx->code_gen_buffer_size;
+            split_cross_256mb(&buf2, &size2, buf, size);
             if (buf == buf2) {
                 munmap(buf + size2, size - size2);
             } else {
-- 
2.25.1

Richard Henderson <richard.henderson@linaro.org> writes:

> Return output buffer and size via output pointer arguments,
> rather than returning size via tcg_ctx->code_gen_buffer_size.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

This is giving off string "lipstick on a pig" energy but given it's to
work around mips foibles:

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>

-- 
Alex Bennée

From: Richard Henderson <richard.henderson@linaro.org>
> Return output buffer and size via output pointer arguments, rather than
> returning size via tcg_ctx->code_gen_buffer_size.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tcg/region.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/tcg/region.c b/tcg/region.c index b44246e1aa..652f328d2c 100644
> --- a/tcg/region.c
> +++ b/tcg/region.c
> @@ -467,7 +467,8 @@ static inline bool cross_256mb(void *addr, size_t size)
>  /* We weren't able to allocate a buffer without crossing that boundary,
>     so make do with the larger portion of the buffer that doesn't cross.
>     Returns the new base of the buffer, and adjusts code_gen_buffer_size.  */ -
> static inline void *split_cross_256mb(void *buf1, size_t size1)
> +static inline void split_cross_256mb(void **obuf, size_t *osize,
> +                                     void *buf1, size_t size1)

Need to adjust the comment, now that we're no longer adjusting code_gen_buffer_size in here.


> @@ -583,8 +583,7 @@ static bool alloc_code_gen_buffer_anon(size_t size, int
> prot,
>              /* fallthru */
>          default:
>              /* Split the original buffer.  Free the smaller half.  */
> -            buf2 = split_cross_256mb(buf, size);
> -            size2 = tcg_ctx->code_gen_buffer_size;
> +            split_cross_256mb(&buf2, &size2, buf, size);

This will be fixed by patch 21 (tcg: Allocate code_gen_buffer into struct tcg_region_state), but shouldn't we update tcg_ctx->code_gen_buffer_size here?

Other than that,

Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>

--
Luis Pires
Instituto de Pesquisas ELDORADO
Aviso Legal - Disclaimer <https://www.eldorado.org.br/disclaimer.html>

On 6/9/21 7:59 AM, Luis Fernando Fujita Pires wrote:
> From: Richard Henderson <richard.henderson@linaro.org>
>> Return output buffer and size via output pointer arguments, rather than
>> returning size via tcg_ctx->code_gen_buffer_size.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   tcg/region.c | 15 +++++++--------
>>   1 file changed, 7 insertions(+), 8 deletions(-)
>>
>> diff --git a/tcg/region.c b/tcg/region.c index b44246e1aa..652f328d2c 100644
>> --- a/tcg/region.c
>> +++ b/tcg/region.c
>> @@ -467,7 +467,8 @@ static inline bool cross_256mb(void *addr, size_t size)
>>   /* We weren't able to allocate a buffer without crossing that boundary,
>>      so make do with the larger portion of the buffer that doesn't cross.
>>      Returns the new base of the buffer, and adjusts code_gen_buffer_size.  */ -
>> static inline void *split_cross_256mb(void *buf1, size_t size1)
>> +static inline void split_cross_256mb(void **obuf, size_t *osize,
>> +                                     void *buf1, size_t size1)
> 
> Need to adjust the comment, now that we're no longer adjusting code_gen_buffer_size in here.

Done, thanks.

>> @@ -583,8 +583,7 @@ static bool alloc_code_gen_buffer_anon(size_t size, int
>> prot,
>>               /* fallthru */
>>           default:
>>               /* Split the original buffer.  Free the smaller half.  */
>> -            buf2 = split_cross_256mb(buf, size);
>> -            size2 = tcg_ctx->code_gen_buffer_size;
>> +            split_cross_256mb(&buf2, &size2, buf, size);
> 
> This will be fixed by patch 21 (tcg: Allocate code_gen_buffer into struct tcg_region_state), but shouldn't we update tcg_ctx->code_gen_buffer_size here?

Good catch.  I moved the store to _size from above to below.


r~