Re: [Intel-gfx] [PATCH] drm/i915: Skip remap_io() calls for non-x86 platforms

[Jani Nikula <jani.nikula@intel.com>]

On Thu, 18 Nov 2021, Mullati Siva <siva.mullati@intel.com> wrote:
> From: Siva Mullati <siva.mullati@intel.com>
>
> Only hw that supports mappable aperture would hit this path
> vm_fault_gtt/vm_fault_tmm, So we never hit these functions
> remap_io_mapping() and remap_io_sg in discrete, So skip this
> code for non-x86 architectures.

Please enable CONFIG_DRM_I915_WERROR=y while developing, and fix the
fallout. The header is not self-contained. To fix that, please use
forward declarations instead of #includes where possible.

BR,
Jani.

>
> Signed-off-by: Siva Mullati <siva.mullati@intel.com>
> ---
>  drivers/gpu/drm/i915/Makefile            |  2 +-
>  drivers/gpu/drm/i915/gem/i915_gem_mman.c |  1 +
>  drivers/gpu/drm/i915/i915_drv.h          |  8 ------
>  drivers/gpu/drm/i915/i915_mm.c           |  1 +
>  drivers/gpu/drm/i915/i915_mm.h           | 31 ++++++++++++++++++++++++
>  5 files changed, 34 insertions(+), 9 deletions(-)
>  create mode 100644 drivers/gpu/drm/i915/i915_mm.h
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 074d6b8edd23..b08397e41efb 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -62,12 +62,12 @@ i915-y += i915_driver.o \
>  i915-y += \
>  	dma_resv_utils.o \
>  	i915_memcpy.o \
> -	i915_mm.o \
>  	i915_sw_fence.o \
>  	i915_sw_fence_work.o \
>  	i915_syncmap.o \
>  	i915_user_extensions.o
>  
> +i915-$(CONFIG_X86) += i915_mm.o
>  i915-$(CONFIG_COMPAT)   += i915_ioc32.o
>  i915-$(CONFIG_DEBUG_FS) += \
>  	i915_debugfs.o \
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> index 65fc6ff5f59d..39bb15eafc07 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
> @@ -17,6 +17,7 @@
>  #include "i915_gem_ioctls.h"
>  #include "i915_gem_object.h"
>  #include "i915_gem_mman.h"
> +#include "i915_mm.h"
>  #include "i915_trace.h"
>  #include "i915_user_extensions.h"
>  #include "i915_gem_ttm.h"
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index f2a546d58481..c0712281ee83 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1962,14 +1962,6 @@ mkwrite_device_info(struct drm_i915_private *dev_priv)
>  int i915_reg_read_ioctl(struct drm_device *dev, void *data,
>  			struct drm_file *file);
>  
> -/* i915_mm.c */
> -int remap_io_mapping(struct vm_area_struct *vma,
> -		     unsigned long addr, unsigned long pfn, unsigned long size,
> -		     struct io_mapping *iomap);
> -int remap_io_sg(struct vm_area_struct *vma,
> -		unsigned long addr, unsigned long size,
> -		struct scatterlist *sgl, resource_size_t iobase);
> -
>  static inline int intel_hws_csb_write_index(struct drm_i915_private *i915)
>  {
>  	if (GRAPHICS_VER(i915) >= 11)
> diff --git a/drivers/gpu/drm/i915/i915_mm.c b/drivers/gpu/drm/i915/i915_mm.c
> index 666808cb3a32..f4df15fe7cf8 100644
> --- a/drivers/gpu/drm/i915/i915_mm.c
> +++ b/drivers/gpu/drm/i915/i915_mm.c
> @@ -27,6 +27,7 @@
>  
>  
>  #include "i915_drv.h"
> +#include "i915_mm.h"
>  
>  struct remap_pfn {
>  	struct mm_struct *mm;
> diff --git a/drivers/gpu/drm/i915/i915_mm.h b/drivers/gpu/drm/i915/i915_mm.h
> new file mode 100644
> index 000000000000..71651cced0f5
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/i915_mm.h
> @@ -0,0 +1,31 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2021 Intel Corporation
> + */
> +
> +#ifndef __I915_MM_H__
> +#define __I915_MM_H__
> +
> +#if IS_ENABLED(CONFIG_X86)
> +int remap_io_mapping(struct vm_area_struct *vma,
> +                     unsigned long addr, unsigned long pfn, unsigned long size,
> +                     struct io_mapping *iomap);
> +int remap_io_sg(struct vm_area_struct *vma,
> +                unsigned long addr, unsigned long size,
> +                struct scatterlist *sgl, resource_size_t iobase);
> +#else
> +static inline int remap_io_mapping(struct vm_area_struct *vma,
> +                     unsigned long addr, unsigned long pfn, unsigned long size,
> +                     struct io_mapping *iomap)
> +{
> +        return 0;
> +}
> +static inline int remap_io_sg(struct vm_area_struct *vma,
> +                unsigned long addr, unsigned long size,
> +                struct scatterlist *sgl, resource_size_t iobase)
> +{
> +        return 0;
> +}
> +#endif
> +
> +#endif /* __I915_MM_H__ */

-- 
Jani Nikula, Intel Open Source Graphics Center