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

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

On Tue, 30 Nov 2021, Lucas De Marchi <lucas.demarchi@intel.com> wrote:
> On Mon, Nov 22, 2021 at 06:01:42PM +0530, Mullati Siva 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 this function
>>remap_io_mapping() in discrete, So skip this code for non-x86
>>architectures.
>>
>>Signed-off-by: Siva Mullati <siva.mullati@intel.com>
>>---
>> 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           | 32 ++++++++++++++++++++++++
>> 4 files changed, 34 insertions(+), 8 deletions(-)
>> create mode 100644 drivers/gpu/drm/i915/i915_mm.h
>>
>>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 1bfadd9127fc..7ae0f0cc6866 100644
>>--- a/drivers/gpu/drm/i915/i915_drv.h
>>+++ b/drivers/gpu/drm/i915/i915_drv.h
>>@@ -1967,14 +1967,6 @@ 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..1d3bbb9cbf43
>>--- /dev/null
>>+++ b/drivers/gpu/drm/i915/i915_mm.h
>>@@ -0,0 +1,32 @@
>>+/* SPDX-License-Identifier: MIT */
>>+/*
>>+ * Copyright © 2021 Intel Corporation
>>+ */
>>+
>>+#ifndef __I915_MM_H__
>>+#define __I915_MM_H__
>>+
>>+#include <linux/types.h>
>>+
>>+struct vm_area_struct;
>>+struct io_mapping;
>>+struct scatterlist;
>>+
>>+#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);
>>+#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)
>>+{
>
> would probably be good to add:
>
> 	pr_err("Architecture has no remap_io_mapping() and shouldn't be calling this function\n");
> 	WARN_ON_ONCE(1);
>
> the same way that is done in drivers/gpu/drm/drm_cache.c
>
> Other than that:
>
>
> Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
>
> Since you're adding this header, can you follow up with one additional
> patch to move the rest of the prototypes off i915_drv.h and into this
> new header?

There's only the two functions?

BR,
Jani.


>
>
> thanks
> Lucas De Marchi
>
>
>>+	return 0;
>>+}
>>+#endif
>>+
>>+int remap_io_sg(struct vm_area_struct *vma,
>>+		unsigned long addr, unsigned long size,
>>+		struct scatterlist *sgl, resource_size_t iobase);
>>+
>>+#endif /* __I915_MM_H__ */
>>-- 
>>2.33.0
>>

-- 
Jani Nikula, Intel Open Source Graphics Center