Re: [PATCH v2 2/6] drm/ttm: add drm gem ttm helpers, starting with drm_gem_ttm_print_info()

[Daniel Vetter]

On Tue, Sep 03, 2019 at 12:12:44PM +0200, Gerd Hoffmann wrote:
> Now with ttm_buffer_object being a subclass of drm_gem_object we can
> easily lookup ttm_buffer_object for a given drm_gem_object, which in
> turn allows to create common helper functions.
> 
> This patch starts off with a drm_gem_ttm_print_info() helper function
> which prints adds some ttm specific lines to the debug output.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
> ---
>  include/drm/drm_gem_ttm_helper.h     | 19 ++++++++++
>  drivers/gpu/drm/drm_gem_ttm_helper.c | 53 ++++++++++++++++++++++++++++
>  Documentation/gpu/drm-mm.rst         | 12 +++++++
>  drivers/gpu/drm/Kconfig              |  7 ++++
>  drivers/gpu/drm/Makefile             |  3 ++
>  5 files changed, 94 insertions(+)
>  create mode 100644 include/drm/drm_gem_ttm_helper.h
>  create mode 100644 drivers/gpu/drm/drm_gem_ttm_helper.c
> 
> diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h
> new file mode 100644
> index 000000000000..6268f89c5a48
> --- /dev/null
> +++ b/include/drm/drm_gem_ttm_helper.h
> @@ -0,0 +1,19 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +
> +#ifndef DRM_GEM_TTM_HELPER_H
> +#define DRM_GEM_TTM_HELPER_H
> +
> +#include <linux/kernel.h>
> +
> +#include <drm/drm_gem.h>
> +#include <drm/drm_device.h>
> +#include <drm/ttm/ttm_bo_api.h>
> +#include <drm/ttm/ttm_bo_driver.h>
> +
> +#define drm_gem_ttm_of_gem(gem_obj) \
> +	container_of(gem_obj, struct ttm_buffer_object, base)
> +
> +void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
> +			    const struct drm_gem_object *gem);
> +
> +#endif
> diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c
> new file mode 100644
> index 000000000000..5a19a7e130c4
> --- /dev/null
> +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c
> @@ -0,0 +1,53 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +
> +#include <linux/module.h>
> +
> +#include <drm/drm_gem_ttm_helper.h>
> +
> +/**
> + * DOC: overview
> + *
> + * This library provides helper functions for gem objects backed by
> + * ttm.
> + */
> +
> +/**
> + * drm_gem_ttm_print_info() - Print &ttm_buffer_object info for debugfs
> + * @p: DRM printer
> + * @indent: Tab indentation level
> + * @gem: GEM object
> + *
> + * This function can be used as the &drm_driver->gem_print_info callback.

&drm_gem_object_funcs.print_info is the new thing. Also I think you need
the . for kerneldoc to parse this correctly and make it a link.

> + */
> +void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
> +			    const struct drm_gem_object *gem)
> +{
> +	static const char const *plname[] = {
> +		[ TTM_PL_SYSTEM ] = "system",
> +		[ TTM_PL_TT     ] = "tt",
> +		[ TTM_PL_VRAM   ] = "vram",
> +		[ TTM_PL_PRIV   ] = "priv",
> +
> +		[ 16 ]            = "cached",
> +		[ 17 ]            = "uncached",
> +		[ 18 ]            = "wc",
> +		[ 19 ]            = "contig",
> +
> +		[ 21 ]            = "pinned", /* NO_EVICT */
> +		[ 22 ]            = "topdown",
> +	};
> +	const struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
> +
> +	drm_print_bits(p, indent, "placement", bo->mem.placement,
> +		       plname, ARRAY_SIZE(plname));
> +	if (bo->mem.bus.is_iomem) {
> +		drm_printf_indent(p, indent, "bus.base=%lx\n",
> +				  (unsigned long)bo->mem.bus.base);
> +		drm_printf_indent(p, indent, "bus.offset=%lx\n",
> +				  (unsigned long)bo->mem.bus.offset);
> +	}
> +}
> +EXPORT_SYMBOL(drm_gem_ttm_print_info);
> +
> +MODULE_DESCRIPTION("DRM gem ttm helpers");
> +MODULE_LICENSE("GPL");
> diff --git a/Documentation/gpu/drm-mm.rst b/Documentation/gpu/drm-mm.rst
> index b664f054c259..a70a1d9f30ec 100644
> --- a/Documentation/gpu/drm-mm.rst
> +++ b/Documentation/gpu/drm-mm.rst
> @@ -412,6 +412,18 @@ VRAM MM Helper Functions Reference
>  .. kernel-doc:: drivers/gpu/drm/drm_vram_mm_helper.c
>     :export:
>  
> +GEM TTM Helper Functions Reference
> +-----------------------------------
> +
> +.. kernel-doc:: drivers/gpu/drm/drm_gem_ttm_helper.c
> +   :doc: overview
> +
> +.. kernel-doc:: include/drm/drm_gem_ttm_helper.h
> +   :internal:
> +
> +.. kernel-doc:: drivers/gpu/drm/drm_gem_ttm_helper.c
> +   :export:
> +
>  VMA Offset Manager
>  ==================
>  
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index e6f40fb54c9a..f7b25519f95c 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -172,6 +172,13 @@ config DRM_VRAM_HELPER
>  	help
>  	  Helpers for VRAM memory management
>  
> +config DRM_TTM_HELPER
> +	tristate
> +	depends on DRM
> +	select DRM_TTM
> +	help
> +	  Helpers for ttm-based gem objects
> +
>  config DRM_GEM_CMA_HELPER
>  	bool
>  	depends on DRM
> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> index 10f8329a8b71..545c61d6528b 100644
> --- a/drivers/gpu/drm/Makefile
> +++ b/drivers/gpu/drm/Makefile
> @@ -37,6 +37,9 @@ drm_vram_helper-y := drm_gem_vram_helper.o \
>  		     drm_vram_mm_helper.o
>  obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o
>  
> +drm_ttm_helper-y := drm_gem_ttm_helper.o
> +obj-$(CONFIG_DRM_TTM_HELPER) += drm_ttm_helper.o
> +
>  drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_dsc.o drm_probe_helper.o \
>  		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
>  		drm_kms_helper_common.o drm_dp_dual_mode_helper.o \

Nice! With the kerneldoc bikeshed fixed:

Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>

> -- 
> 2.18.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch