drm/msm: allow compile_test on !ARM

MSM is one of the few drivers which won't even compile
test on !ARM platforms.

Looking into this a bit more it turned out that there is
actually not that much missing to at least let the driver
compile on x86 as well.

So this patch replaces the use of phys_to_page() with the
open coded version and provides a dummy for of_drm_find_bridge().
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924071759.22659-2-christian.koenig@amd.com

drivers/gpu/drm/msm/Kconfig

@@ -3,9 +3,9 @@
 config DRM_MSM
 	tristate "MSM DRM"
 	depends on DRM
-	depends on ARCH_QCOM || SOC_IMX5 || (ARM && COMPILE_TEST)
+	depends on ARCH_QCOM || SOC_IMX5 || COMPILE_TEST
 	depends on IOMMU_SUPPORT
-	depends on OF && COMMON_CLK
+	depends on (OF && COMMON_CLK) || COMPILE_TEST
 	depends on QCOM_OCMEM || QCOM_OCMEM=n
 	depends on QCOM_LLCC || QCOM_LLCC=n
 	depends on QCOM_COMMAND_DB || QCOM_COMMAND_DB=n

drivers/gpu/drm/msm/msm_gem.c

@@ -85,7 +85,7 @@ static struct page **get_pages_vram(struct drm_gem_object *obj, int npages)
 
 	paddr = physaddr(obj);
 	for (i = 0; i < npages; i++) {
-		p[i] = phys_to_page(paddr);
+		p[i] = pfn_to_page(__phys_to_pfn(paddr));
 		paddr += PAGE_SIZE;
 	}
 

include/drm/drm_bridge.h

@@ -790,11 +790,19 @@ drm_priv_to_bridge(struct drm_private_obj *priv)
 
 void drm_bridge_add(struct drm_bridge *bridge);
 void drm_bridge_remove(struct drm_bridge *bridge);
-struct drm_bridge *of_drm_find_bridge(struct device_node *np);
 int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge,
 		      struct drm_bridge *previous,
 		      enum drm_bridge_attach_flags flags);
 
+#ifdef CONFIG_OF
+struct drm_bridge *of_drm_find_bridge(struct device_node *np);
+#else
+static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
+{
+	return NULL;
+}
+#endif
+
 /**
  * drm_bridge_get_next_bridge() - Get the next bridge in the chain
  * @bridge: bridge object