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

[Mullati Siva]

From: Siva Mullati <siva.mullati at 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.

v2: use IS_ENABLED () instead of #if defined

v3: move function prototypes from i915_drv.h to i915_mm.h

v4: added kernel error message in stub function

Signed-off-by: Siva Mullati <siva.mullati at 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           | 35 ++++++++++++++++++++++++
 4 files changed, 37 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..dc5333356c8f
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_mm.h
@@ -0,0 +1,35 @@
+/* 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)
+{
+	pr_err(DRIVER_NAME
+		": Architecture has no remap_io_mapping() and shouldn't be calling this function\n");
+	WARN_ON_ONCE(1);
+	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