drm/sysfb: Fix efidrm error handling and memory type mismatch

Fix incorrect error checking and memory type confusion in
efidrm_device_create(). devm_memremap() returns error pointers, not
NULL, and returns system memory while devm_ioremap() returns I/O memory.
The code incorrectly passes system memory to iosys_map_set_vaddr_iomem().

Restructure to handle each memory type separately. Use devm_ioremap*()
with ERR_PTR(-ENXIO) for WC/UC, and devm_memremap() with ERR_CAST() for
WT/WB.

Fixes: 32ae90c66fb6 ("drm/sysfb: Add efidrm for EFI displays")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260311064652.2903449-1-nichen@iscas.ac.cn

diff --git a/drivers/gpu/drm/sysfb/efidrm.c b/drivers/gpu/drm/sysfb/efidrm.c
index 50e0aeef709cb12e51d6b9be9b05567c90fe2d2c..9d84caf6962767f39df0139dc4fdfa69c4ad391b 100644 (file)
--- a/drivers/gpu/drm/sysfb/efidrm.c
+++ b/drivers/gpu/drm/sysfb/efidrm.c
@@ -151,7 +151,6 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv,
        struct drm_sysfb_device *sysfb;
        struct drm_device *dev;
        struct resource *mem = NULL;
-       void __iomem *screen_base = NULL;
        struct drm_plane *primary_plane;
        struct drm_crtc *crtc;
        struct drm_encoder *encoder;
@@ -238,21 +237,38 @@ static struct efidrm_device *efidrm_device_create(struct drm_driver *drv,
 
        mem_flags = efidrm_get_mem_flags(dev, res->start, vsize);
 
-       if (mem_flags & EFI_MEMORY_WC)
-               screen_base = devm_ioremap_wc(&pdev->dev, mem->start, resource_size(mem));
-       else if (mem_flags & EFI_MEMORY_UC)
-               screen_base = devm_ioremap(&pdev->dev, mem->start, resource_size(mem));
-       else if (mem_flags & EFI_MEMORY_WT)
-               screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem),
-                                           MEMREMAP_WT);
-       else if (mem_flags & EFI_MEMORY_WB)
-               screen_base = devm_memremap(&pdev->dev, mem->start, resource_size(mem),
-                                           MEMREMAP_WB);
-       else
+       if (mem_flags & EFI_MEMORY_WC) {
+               void __iomem *screen_base = devm_ioremap_wc(&pdev->dev, mem->start,
+                                                           resource_size(mem));
+
+               if (!screen_base)
+                       return ERR_PTR(-ENXIO);
+               iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
+       } else if (mem_flags & EFI_MEMORY_UC) {
+               void __iomem *screen_base = devm_ioremap(&pdev->dev, mem->start,
+                                                        resource_size(mem));
+
+               if (!screen_base)
+                       return ERR_PTR(-ENXIO);
+               iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
+       } else if (mem_flags & EFI_MEMORY_WT) {
+               void *screen_base = devm_memremap(&pdev->dev, mem->start,
+                                                 resource_size(mem), MEMREMAP_WT);
+
+               if (IS_ERR(screen_base))
+                       return ERR_CAST(screen_base);
+               iosys_map_set_vaddr(&sysfb->fb_addr, screen_base);
+       } else if (mem_flags & EFI_MEMORY_WB) {
+               void *screen_base = devm_memremap(&pdev->dev, mem->start,
+                                                 resource_size(mem), MEMREMAP_WB);
+
+               if (IS_ERR(screen_base))
+                       return ERR_CAST(screen_base);
+               iosys_map_set_vaddr(&sysfb->fb_addr, screen_base);
+       } else {
                drm_err(dev, "invalid mem_flags: 0x%llx\n", mem_flags);
-       if (!screen_base)
-               return ERR_PTR(-ENOMEM);
-       iosys_map_set_vaddr_iomem(&sysfb->fb_addr, screen_base);
+               return ERR_PTR(-EINVAL);
+       }
 
        /*
         * Modesetting