[Mesa-dev] [PATCH] clover: Pass buffer offsets to the driver in set_global_binding()

[Francisco Jerez]

Tom Stellard <tom at stellard.net> writes:

> From: Tom Stellard <thomas.stellard at amd.com>
>
> The offsets will be stored in the handles parameter.  This makes
> it possible to use sub-buffers.
> ---
>  src/gallium/drivers/r600/evergreen_compute.c      |  2 +-
>  src/gallium/drivers/radeonsi/si_compute.c         |  1 +
>  src/gallium/include/pipe/p_context.h              |  9 ++++++---
>  src/gallium/state_trackers/clover/core/kernel.cpp | 11 +++++++++--
>  4 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/src/gallium/drivers/r600/evergreen_compute.c b/src/gallium/drivers/r600/evergreen_compute.c
> index 70efe5c..ee00a24 100644
> --- a/src/gallium/drivers/r600/evergreen_compute.c
> +++ b/src/gallium/drivers/r600/evergreen_compute.c
> @@ -665,7 +665,7 @@ static void evergreen_set_global_binding(
>  		assert(resources[i]->target == PIPE_BUFFER);
>  		assert(resources[i]->bind & PIPE_BIND_GLOBAL);
>  
> -		*(handles[i]) = buffers[i]->chunk->start_in_dw * 4;
> +		*(handles[i]) += buffers[i]->chunk->start_in_dw * 4;
>  	}
>  
>  	evergreen_set_rat(ctx->cs_shader_state.shader, 0, pool->bo, 0, pool->size_in_dw * 4);
> diff --git a/src/gallium/drivers/radeonsi/si_compute.c b/src/gallium/drivers/radeonsi/si_compute.c
> index a7f49e7..e0e6bb4 100644
> --- a/src/gallium/drivers/radeonsi/si_compute.c
> +++ b/src/gallium/drivers/radeonsi/si_compute.c
> @@ -109,6 +109,7 @@ static void si_set_global_binding(
>  		uint64_t va;
>  		program->global_buffers[i] = resources[i];
>  		va = r600_resource_va(ctx->screen, resources[i]);
> +		va += *handles[i];
>  		memcpy(handles[i], &va, sizeof(va));
>  	}
>  }
> diff --git a/src/gallium/include/pipe/p_context.h b/src/gallium/include/pipe/p_context.h
> index 8ef6e27..eef0a63 100644
> --- a/src/gallium/include/pipe/p_context.h
> +++ b/src/gallium/include/pipe/p_context.h
> @@ -461,9 +461,12 @@ struct pipe_context {
>      *                   resources will be bound.
>      * \param handles    array of pointers to the memory locations that
>      *                   will be filled with the respective base
> -    *                   addresses each buffer will be mapped to.  It
> -    *                   should contain at least \a count elements,
> -    *                   unless \a resources is NULL in which case \a
> +    *                   addresses each buffer will be mapped to.  When
> +    *                   this function is called, the value at these memory
> +    *                   locations will be the offset in bytes from
> +    *                   the start of the buffer that should be used to
> +    *                   compute the handle.  It should contain at least \a count
> +    *                   elements, unless \a resources is NULL in which case \a
>      *                   handles should be NULL as well.
>      *

Maybe something like this would be easier to understand?

|    * \param handles    array of pointers to the memory locations that
|    *                   will be updated with the address each buffer
|    *                   will be mapped to.  The base memory address of
|    *                   each of the buffers will be added to the value
|    *                   pointed to by its corresponding handle to form
|    *                   the final address argument.  It should contain
|    *                   at least \a count elements, unless \a
|    *                   resources is NULL in which case \a handles
|    *                   should be NULL as well.

>      * Note that the driver isn't required to make any guarantees about
> diff --git a/src/gallium/state_trackers/clover/core/kernel.cpp b/src/gallium/state_trackers/clover/core/kernel.cpp
> index 6d894cd..06eff85 100644
> --- a/src/gallium/state_trackers/clover/core/kernel.cpp
> +++ b/src/gallium/state_trackers/clover/core/kernel.cpp
> @@ -337,8 +337,15 @@ kernel::global_argument::bind(exec_context &ctx,
>     align(ctx.input, marg.target_align);
>  
>     if (buf) {
> -      ctx.g_handles.push_back(allocate(ctx.input, marg.target_size));
> -      ctx.g_buffers.push_back(buf->resource(*ctx.q).pipe);
> +      resource &r = buf->resource(*ctx.q);

This could be 'const resource &'.

> +      ctx.g_handles.push_back(ctx.input.size());
> +      ctx.g_buffers.push_back(r.pipe);
> +
> +      // XXX: How to handle multi-demensional offsets?

They're not an issue, you can safely assume that the offset is
one-dimensional because CL doesn't support sub-images, only sub-buffers.

> +      assert(!r.offset[1] && !r.offset[2]);
> +      std::vector<uint8_t> offset = bytes(r.offset[0]);

'auto v' for consistency?

> +      extend(offset, marg.ext_type, marg.target_size);

We should call byteswap() here.

> +      insert(ctx.input, offset);
>     } else {
>        // Null pointer.
>        allocate(ctx.input, marg.target_size);

Would you mind fixing constant sub-buffers too?  My plan was to pass the
offset in the low bits of the input argument, like:
'bytes(ctx.resources.size() << 24 | r.offset[0])'.  They should be even
easier than global sub-buffers.

Thanks.

> -- 
> 1.8.1.5
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 229 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20140215/1cf6dcd5/attachment.pgp>