diff mbox series

[v3,19/28] tcg: Tidy split_cross_256mb

Message ID 20210502231844.1977630-20-richard.henderson@linaro.org
State New
Headers show
Series tcg: Clean up code_gen_buffer allocation | expand

Commit Message

Richard Henderson May 2, 2021, 11:18 p.m. UTC
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(-)

-- 
2.25.1

Comments

Alex Bennée June 9, 2021, 10:01 a.m. UTC | #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
Luis Fernando Fujita Pires June 9, 2021, 2:59 p.m. UTC | #2
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>
Richard Henderson June 10, 2021, 3:20 p.m. UTC | #3
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~
diff mbox series

Patch

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 {