[Mesa-dev] [PATCH] gallium/include/pipe: Added interface for atomic counter buffers in pipe
Ilia Mirkin
imirkin at alum.mit.edu
Mon Nov 17 08:28:33 PST 2014
Because shader resources were already specified as pipe_surfaces (in
the existing, albeit presently unused API). A pipe_surface is a
wrapper around a resource that specifies what "view" of the resource
should be writable, and attaches an optional format to that resource.
Normally pipe_surfaces are used for render targets, but it applies
just as well here. It applies especially well with a view towards
ARB_shader_image_load_store.
It's conceivable to make a totally separate thing for atomic buffers,
but there's no good reason to -- they will have to be handled in
essentially the same way as regular "image" surfaces will for
ARB_shader_image_load_store.
Cheers,
-ilia
On Mon, Nov 17, 2014 at 11:19 AM, Aditya Avinash
<adityaavinash1 at gmail.com> wrote:
> Hi,
> I am having difficulty in understanding why you implemented pipe_surface in
> st_atom_atomicbuf.c.
>
> On Mon, Nov 17, 2014 at 2:24 AM, Aditya Avinash <adityaavinash1 at gmail.com>
> wrote:
>>
>> Hi,
>>
>> On Sunday, November 16, 2014, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>>
>>> The direction I went in was by adapting the shader resources interface
>>> for this. I believe it will be possible to use for
>>> shader_image_load_store as well.
>>
>>
>> I asked some questions on mailing list about the implementation. I took
>> the same path as uniform buffers. But, I realized that it's not efficient to
>> do that.
>>
>>>
>>> See https://github.com/imirkin/mesa/commits/atomic
>>>
>>
>> The commits are similar to my previous patch. I was doing atomics similar
>> to uniform buffers, Now I was changing cso_context.
>>
>>>
>>> I believe that makes a lot more sense than creating a special counter
>>> buffer type only to be used for this. pipe_surface has the requisite
>>> offset/etc options.
>>
>>
>> I thought of using uniform buffer data structure with certain flags which
>> differentiate between atomics, uniforms, index. Like a generic buffer.
>>
>>>
>>> I feel like I've mentioned this before when you asked questions, but
>>> I'd highly recommend taking my work and improving on it (or at least
>>> understanding it). It's at the point where a driver can implement the
>>> backend logic, although some of the mesa/st bits are going to be
>>> subject to discussion (and need fixing, it messes up the DCE tgsi
>>> pass, so I just disabled it).
>>>
>>> On Thu, Nov 13, 2014 at 12:18 AM, adityaatluri <adityaavinash1 at gmail.com>
>>> wrote:
>>> > ---
>>> > src/gallium/include/pipe/p_context.h | 5 +++++
>>> > src/gallium/include/pipe/p_defines.h | 7 ++++++-
>>> > src/gallium/include/pipe/p_state.h | 10 ++++++++++
>>> > 3 files changed, 21 insertions(+), 1 deletion(-)
>>> >
>>> > diff --git a/src/gallium/include/pipe/p_context.h
>>> > b/src/gallium/include/pipe/p_context.h
>>> > index af5674f..bf3be31 100644
>>> > --- a/src/gallium/include/pipe/p_context.h
>>> > +++ b/src/gallium/include/pipe/p_context.h
>>> > @@ -44,6 +44,7 @@ struct pipe_blit_info;
>>> > struct pipe_box;
>>> > struct pipe_clip_state;
>>> > struct pipe_constant_buffer;
>>> > +struct pipe_counter_buffer;
>>> > struct pipe_depth_stencil_alpha_state;
>>> > struct pipe_draw_info;
>>> > struct pipe_fence_handle;
>>> > @@ -201,6 +202,10 @@ struct pipe_context {
>>> > uint shader, uint index,
>>> > struct pipe_constant_buffer *buf );
>>> >
>>> > + void (*set_counter_buffer)( struct pipe_context *,
>>> > + uint shader, uint index,
>>> > + struct pipe_counter_buffer *buf );
>>> > +
>>> > void (*set_framebuffer_state)( struct pipe_context *,
>>> > const struct pipe_framebuffer_state
>>> > * );
>>> >
>>> > diff --git a/src/gallium/include/pipe/p_defines.h
>>> > b/src/gallium/include/pipe/p_defines.h
>>> > index 8c4e415..717ab6a 100644
>>> > --- a/src/gallium/include/pipe/p_defines.h
>>> > +++ b/src/gallium/include/pipe/p_defines.h
>>> > @@ -341,6 +341,7 @@ enum pipe_flush_flags {
>>> > #define PIPE_BIND_VERTEX_BUFFER (1 << 4) /* set_vertex_buffers
>>> > */
>>> > #define PIPE_BIND_INDEX_BUFFER (1 << 5) /* draw_elements */
>>> > #define PIPE_BIND_CONSTANT_BUFFER (1 << 6) /* set_constant_buffer
>>> > */
>>> > +#define PIPE_BIND_COUNTER_BUFFER (1 << 7) /* set_counter_buffer
>>> > */
>>> > #define PIPE_BIND_DISPLAY_TARGET (1 << 8) /* flush_front_buffer
>>> > */
>>> > #define PIPE_BIND_TRANSFER_WRITE (1 << 9) /* transfer_map */
>>> > #define PIPE_BIND_TRANSFER_READ (1 << 10) /* transfer_map */
>>> > @@ -572,6 +573,8 @@ enum pipe_cap {
>>> > PIPE_CAP_MAX_VERTEX_ATTRIB_STRIDE = 109,
>>> > PIPE_CAP_SAMPLER_VIEW_TARGET = 110,
>>> > PIPE_CAP_CLIP_HALFZ = 111,
>>> > + PIPE_CAP_USER_COUNTER_BUFFERS = 112,
>>> > + PIPE_CAP_COUNTER_BUFFER_OFFSET_ALIGNMENT = 113,
>>> > };
>>> >
>>> > #define PIPE_QUIRK_TEXTURE_BORDER_COLOR_SWIZZLE_NV50 (1 << 0)
>>> > @@ -631,7 +634,9 @@ enum pipe_shader_cap
>>> > PIPE_SHADER_CAP_PREFERRED_IR,
>>> > PIPE_SHADER_CAP_TGSI_SQRT_SUPPORTED,
>>> > PIPE_SHADER_CAP_MAX_SAMPLER_VIEWS,
>>> > - PIPE_SHADER_CAP_DOUBLES
>>> > + PIPE_SHADER_CAP_DOUBLES,
>>> > + PIPE_SHADER_CAP_MAX_COUNTER_BUFFER_SIZE,
>>> > + PIPE_SHADER_CAP_MAX_COUNTER_BUFFERS
>>> > };
>>> >
>>> > /**
>>> > diff --git a/src/gallium/include/pipe/p_state.h
>>> > b/src/gallium/include/pipe/p_state.h
>>> > index 43bc48b..49fae5d 100644
>>> > --- a/src/gallium/include/pipe/p_state.h
>>> > +++ b/src/gallium/include/pipe/p_state.h
>>> > @@ -57,6 +57,7 @@ extern "C" {
>>> > #define PIPE_MAX_CLIP_PLANES 8
>>> > #define PIPE_MAX_COLOR_BUFS 8
>>> > #define PIPE_MAX_CONSTANT_BUFFERS 32
>>> > +#define PIPE_MAX_COUNTER_BUFFERS 32
>>> > #define PIPE_MAX_SAMPLERS 16
>>> > #define PIPE_MAX_SHADER_INPUTS 32
>>> > #define PIPE_MAX_SHADER_OUTPUTS 48 /* 32 GENERICs + POS, PSIZE, FOG,
>>> > etc. */
>>> > @@ -462,6 +463,15 @@ struct pipe_constant_buffer {
>>> > const void *user_buffer; /**< pointer to a user buffer if buffer
>>> > == NULL */
>>> > };
>>> >
>>> > +/**
>>> > + * A Counter buffer. A new buffer is set everytime a variable with
>>> > + * atomic_uint is defined.
>>> > + */
>>> > +struct pipe_counter_buffer{
>>> > + struct pipe_resource *buffer; /**< The actual buffer */
>>> > + unsigned buffer_offset; /**< The offset to start of data in buffer
>>> > in bytes */
>>> > + const void *user_buffer; /**< The buffer which is created by the
>>> > compiler */
>>> > +};
>>> >
>>> > /**
>>> > * A stream output target. The structure specifies the range vertices
>>> > can
>>> > --
>>> > 1.9.1
>>> >
>>> > _______________________________________________
>>> > mesa-dev mailing list
>>> > mesa-dev at lists.freedesktop.org
>>> > http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>>
>>
>>
>> --
>> Regards,
>> Aditya Atluri,
>> USA.
>>
>>
>
>
>
> --
> Regards,
> Aditya Atluri,
> USA.
>
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