On Wed, Oct 12, 2022 at 10:55:26AM +0200, Tobias Burnus wrote:
> libgomp/nvptx: Prepare for reverse-offload callback handling
>
> This patch adds a stub 'gomp_target_rev' in the host's target.c, which will
> later handle the reverse offload.
> For nvptx, it adds support for forwarding the offload gomp_target_ext call
> to the host by setting values in a struct on the device and querying it on
> the host - invoking gomp_target_rev on the result.
>
> include/ChangeLog:
>
> * cuda/cuda.h (enum CUdevice_attribute): Add
> CU_DEVICE_ATTRIBUTE_UNIFIED_ADDRESSING.
> (CU_MEMHOSTALLOC_DEVICEMAP): Define.
> (cuMemHostAlloc): Add prototype.
>
> libgomp/ChangeLog:
>
> * config/nvptx/icv-device.c (GOMP_DEVICE_NUM_VAR): Remove
> 'static' for this variable.
> * config/nvptx/libgomp-nvptx.h: New file.
> * config/nvptx/target.c: Include it.
> (GOMP_ADDITIONAL_ICVS): Declare extern var.
> (GOMP_REV_OFFLOAD_VAR): Declare var.
> (GOMP_target_ext): Handle reverse offload.
> * libgomp-plugin.h (GOMP_PLUGIN_target_rev): New prototype.
> * libgomp-plugin.c (GOMP_PLUGIN_target_rev): New, call ...
> * target.c (gomp_target_rev): ... this new stub function.
> * libgomp.h (gomp_target_rev): Declare.
> * libgomp.map (GOMP_PLUGIN_1.4): New; add GOMP_PLUGIN_target_rev.
> * plugin/cuda-lib.def (cuMemHostAlloc): Add.
> * plugin/plugin-nvptx.c: Include libgomp-nvptx.h.
> (struct ptx_device): Add rev_data member.
> (nvptx_open_device): Remove async_engines query, last used in
> r10-304-g1f4c5b9b; add unified-address assert check.
> (GOMP_OFFLOAD_get_num_devices): Claim unified address
> support.
> (GOMP_OFFLOAD_load_image): Free rev_fn_table if no
> offload functions exist. Make offload var available
> on host and device.
> (rev_off_dev_to_host_cpy, rev_off_host_to_dev_cpy): New.
> (GOMP_OFFLOAD_run): Handle reverse offload.
Ok, thanks.
Jakub
