Re: [PATCH v6 5/6] fbdev: Move framebuffer I/O helpers into <asm/fb.h>
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2023-05-10 12:35:16
Also in:
dri-devel, linux-arch, linux-m68k, lkml, loongarch, sparclinux
Hi Thomas, On Wed, May 10, 2023 at 1:06 PM Thomas Zimmermann [off-list ref] wrote:
Implement framebuffer I/O helpers, such as fb_read*() and fb_write*(),
in the architecture's <asm/fb.h> header file or the generic one.
The common case has been the use of regular I/O functions, such as
__raw_readb() or memset_io(). A few architectures used plain system-
memory reads and writes. Sparc used helpers for its SBus.
The architectures that used special cases provide the same code in
their __raw_*() I/O helpers. So the patch replaces this code with the
__raw_*() functions and moves it to <asm-generic/fb.h> for all
architectures.
v6:
* fix fb_readq()/fb_writeq() on 64-bit mips (kernel test robot)
v5:
* include <linux/io.h> in <asm-generic/fb>; fix s390 build
v4:
* ia64, loongarch, sparc64: add fb_mem*() to arch headers
to keep current semantics (Arnd)
v3:
* implement all architectures with generic helpers
* support reordering and native byte order (Geert, Arnd)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Sui Jingfeng <redacted>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
add mips fb_q()quoted hunk ↗ jump to hunk
--- a/arch/mips/include/asm/fb.h +++ b/arch/mips/include/asm/fb.h@@ -12,6 +12,28 @@ static inline void fb_pgprotect(struct file *file, struct vm_area_struct *vma, } #define fb_pgprotect fb_pgprotect +/* + * MIPS doesn't define __raw_ I/O macros, so the helpers + * in <asm-generic/fb.h> don't generate fb_readq() and + * fb_write(). We have to provide them here.
MIPS does not include <asm-generic/io.h>, nor define its own __raw_readq() and __raw_writeq()...
+ *
+ * TODO: Convert MIPS to generic I/O. The helpers below can
+ * then be removed.
+ */
+#ifdef CONFIG_64BIT
+static inline u64 fb_readq(const volatile void __iomem *addr)
+{
+ return __raw_readq(addr);... so how can this call work?
+}
+#define fb_readq fb_readq
+
+static inline void fb_writeq(u64 b, volatile void __iomem *addr)
+{
+ __raw_writeq(b, addr);
+}
+#define fb_writeq fb_writeq
+#endif
+
#include <asm-generic/fb.h>
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds