Re: [PATCH v3 01/41] tcg: Enhance flush_icache_range with separate data pointer

[Alex Bennée]

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

> We are shortly going to have a split rw/rx jit buffer.  Depending
> on the host, we need to flush the dcache at the rw data pointer and
> flush the icache at the rx code pointer.
>
> For now, the two passed pointers are identical, so there is no
> effective change in behaviour.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tcg/aarch64/tcg-target.h     |  9 +++++++--
>  tcg/arm/tcg-target.h         |  8 ++++++--
>  tcg/i386/tcg-target.h        |  3 ++-
>  tcg/mips/tcg-target.h        |  8 ++++++--
>  tcg/ppc/tcg-target.h         |  2 +-
>  tcg/riscv/tcg-target.h       |  8 ++++++--
>  tcg/s390/tcg-target.h        |  3 ++-
>  tcg/sparc/tcg-target.h       |  8 +++++---
>  tcg/tci/tcg-target.h         |  3 ++-
>  softmmu/physmem.c            |  9 ++++++++-
>  tcg/tcg.c                    |  6 ++++--
>  tcg/aarch64/tcg-target.c.inc |  2 +-
>  tcg/mips/tcg-target.c.inc    |  2 +-
>  tcg/ppc/tcg-target.c.inc     | 21 +++++++++++----------
>  tcg/sparc/tcg-target.c.inc   |  4 ++--
>  15 files changed, 64 insertions(+), 32 deletions(-)
>
> diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h
> index 663dd0b95e..d0a6a059b7 100644
> --- a/tcg/aarch64/tcg-target.h
> +++ b/tcg/aarch64/tcg-target.h
> @@ -148,9 +148,14 @@ typedef enum {
>  #define TCG_TARGET_DEFAULT_MO (0)
>  #define TCG_TARGET_HAS_MEMORY_BSWAP     1
>  
> -static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
> +/* Flush the dcache at RW, and the icache at RX, as necessary. */
> +static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t 
> len)
>  {
> -    __builtin___clear_cache((char *)start, (char *)stop);
> +    /* TODO: Copy this from gcc to avoid 4 loops instead of 2. */

Why not do it now?

> +    if (rw != rx) {
> +        __builtin___clear_cache((char *)rw, (char *)(rw + len));
> +    }
> +    __builtin___clear_cache((char *)rx, (char *)(rx + len));
>  }
>  
<snip>
>  
> -static inline void flush_icache_range(uintptr_t start, uintptr_t stop)
> +/* Flush the dcache at RW, and the icache at RX, as necessary. */
> +static inline void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t 
> len)
>  {
>  }

I take it i386 is just too primitive to care about flushing things?

Anyway:

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

-- 
Alex Bennée