fbdev: Replace fb_pgprotect() with pgprot_framebuffer()

Rename the fbdev mmap helper fb_pgprotect() to pgprot_framebuffer().
The helper sets VMA page-access flags for framebuffers in device I/O
memory.

Also clean up the helper's parameters and return value. Instead of
the VMA instance, pass the individial parameters separately: existing
page-access flags, the VMAs start and end addresses and the offset
in the underlying device memory rsp file. Return the new page-access
flags. These changes align pgprot_framebuffer() with other pgprot_()
functions.

v4:
	* fix commit message (Christophe)
v3:
	* rename fb_pgprotect() to pgprot_framebuffer() (Arnd)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230922080636.26762-3-tzimmermann@suse.de

arch/ia64/include/asm/fb.h

@@ -8,17 +8,16 @@
 
 #include <asm/page.h>
 
-struct file;
-
-static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
-				unsigned long off)
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
 {
-	if (efi_range_is_wc(vma->vm_start, vma->vm_end - vma->vm_start))
-		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+	if (efi_range_is_wc(vm_start, vm_end - vm_start))
+		return pgprot_writecombine(prot);
 	else
-		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+		return pgprot_noncached(prot);
 }
-#define fb_pgprotect fb_pgprotect
+#define pgprot_framebuffer pgprot_framebuffer
 
 static inline void fb_memcpy_fromio(void *to, const volatile void __iomem *from, size_t n)
 {

arch/m68k/include/asm/fb.h

@@ -5,26 +5,27 @@
 #include <asm/page.h>
 #include <asm/setup.h>
 
-struct file;
-
-static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
-				unsigned long off)
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
 {
 #ifdef CONFIG_MMU
 #ifdef CONFIG_SUN3
-	pgprot_val(vma->vm_page_prot) |= SUN3_PAGE_NOCACHE;
+	pgprot_val(prot) |= SUN3_PAGE_NOCACHE;
 #else
 	if (CPU_IS_020_OR_030)
-		pgprot_val(vma->vm_page_prot) |= _PAGE_NOCACHE030;
+		pgprot_val(prot) |= _PAGE_NOCACHE030;
 	if (CPU_IS_040_OR_060) {
-		pgprot_val(vma->vm_page_prot) &= _CACHEMASK040;
+		pgprot_val(prot) &= _CACHEMASK040;
 		/* Use no-cache mode, serialized */
-		pgprot_val(vma->vm_page_prot) |= _PAGE_NOCACHE_S;
+		pgprot_val(prot) |= _PAGE_NOCACHE_S;
 	}
 #endif /* CONFIG_SUN3 */
 #endif /* CONFIG_MMU */
+
+	return prot;
 }
-#define fb_pgprotect fb_pgprotect
+#define pgprot_framebuffer pgprot_framebuffer
 
 #include <asm-generic/fb.h>
 

arch/mips/include/asm/fb.h

@@ -3,14 +3,13 @@
 
 #include <asm/page.h>
 
-struct file;
-
-static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
-				unsigned long off)
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
 {
-	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+	return pgprot_noncached(prot);
 }
-#define fb_pgprotect fb_pgprotect
+#define pgprot_framebuffer pgprot_framebuffer
 
 /*
  * MIPS doesn't define __raw_ I/O macros, so the helpers

arch/powerpc/include/asm/fb.h

@@ -2,23 +2,20 @@
 #ifndef _ASM_FB_H_
 #define _ASM_FB_H_
 
-#include <linux/fs.h>
-
 #include <asm/page.h>
 
-static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
-				unsigned long off)
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
 {
 	/*
 	 * PowerPC's implementation of phys_mem_access_prot() does
 	 * not use the file argument. Set it to NULL in preparation
 	 * of later updates to the interface.
 	 */
-	vma->vm_page_prot = phys_mem_access_prot(NULL, PHYS_PFN(off),
-						 vma->vm_end - vma->vm_start,
-						 vma->vm_page_prot);
+	return phys_mem_access_prot(NULL, PHYS_PFN(offset), vm_end - vm_start, prot);
 }
-#define fb_pgprotect fb_pgprotect
+#define pgprot_framebuffer pgprot_framebuffer
 
 #include <asm-generic/fb.h>
 

arch/sparc/include/asm/fb.h

@@ -4,15 +4,18 @@
 
 #include <linux/io.h>
 
+#include <asm/page.h>
+
 struct fb_info;
-struct file;
-struct vm_area_struct;
 
 #ifdef CONFIG_SPARC32
-static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
-				unsigned long off)
-{ }
-#define fb_pgprotect fb_pgprotect
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
+{
+	return prot;
+}
+#define pgprot_framebuffer pgprot_framebuffer
 #endif
 
 int fb_is_primary_device(struct fb_info *info);

arch/x86/include/asm/fb.h

@@ -2,12 +2,14 @@
 #ifndef _ASM_X86_FB_H
 #define _ASM_X86_FB_H
 
+#include <asm/page.h>
+
 struct fb_info;
-struct file;
-struct vm_area_struct;
 
-void fb_pgprotect(struct file *file, struct vm_area_struct *vma, unsigned long off);
-#define fb_pgprotect fb_pgprotect
+pgprot_t pgprot_framebuffer(pgprot_t prot,
+			    unsigned long vm_start, unsigned long vm_end,
+			    unsigned long offset);
+#define pgprot_framebuffer pgprot_framebuffer
 
 int fb_is_primary_device(struct fb_info *info);
 #define fb_is_primary_device fb_is_primary_device

arch/x86/video/fbdev.c

@@ -13,16 +13,17 @@
 #include <linux/vgaarb.h>
 #include <asm/fb.h>
 
-void fb_pgprotect(struct file *file, struct vm_area_struct *vma, unsigned long off)
+pgprot_t pgprot_framebuffer(pgprot_t prot,
+			    unsigned long vm_start, unsigned long vm_end,
+			    unsigned long offset)
 {
-	unsigned long prot;
-
-	prot = pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK;
+	pgprot_val(prot) &= ~_PAGE_CACHE_MASK;
 	if (boot_cpu_data.x86 > 3)
-		pgprot_val(vma->vm_page_prot) =
-			prot | cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS);
+		pgprot_val(prot) |= cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS);
+
+	return prot;
 }
-EXPORT_SYMBOL(fb_pgprotect);
+EXPORT_SYMBOL(pgprot_framebuffer);
 
 int fb_is_primary_device(struct fb_info *info)
 {

drivers/video/fbdev/core/fb_chrdev.c

@@ -365,7 +365,8 @@ static int fb_mmap(struct file *file, struct vm_area_struct *vma)
 	mutex_unlock(&info->mm_lock);
 
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	fb_pgprotect(file, vma, start);
+	vma->vm_page_prot = pgprot_framebuffer(vma->vm_page_prot, vma->vm_start,
+					       vma->vm_end, start);
 
 	return vm_iomap_memory(vma, start, len);
 }

include/asm-generic/fb.h

@@ -12,14 +12,14 @@
 #include <linux/pgtable.h>
 
 struct fb_info;
-struct file;
 
-#ifndef fb_pgprotect
-#define fb_pgprotect fb_pgprotect
-static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma,
-				unsigned long off)
+#ifndef pgprot_framebuffer
+#define pgprot_framebuffer pgprot_framebuffer
+static inline pgprot_t pgprot_framebuffer(pgprot_t prot,
+					  unsigned long vm_start, unsigned long vm_end,
+					  unsigned long offset)
 {
-	vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+	return pgprot_writecombine(prot);
 }
 #endif