Hi Laurent,
On Wed, Jan 19, 2022 at 1:05 AM Laurent Vivier <laurent@xxxxxxxxx> wrote:
The goldfish device always uses the same endianness as the architecture
using it:
https://android.googlesource.com/platform/external/qemu/+/refs/heads/emu-master-dev/hw/timer/goldfish_timer.c#177
On a big-endian machine, the device is also big-endian, on a
little-endian machine the device is little-endian.
So we need to use the right accessor to read/write values to the goldfish
registers: ioread32()/iowrite32() on a little-endian machine,
ioread32be()/iowrite32be() on a big-endian machine.
This patch introduces goldfish_ioread32()/goldfish_iowrite32() to allow
architectures to define them accordlingly to their endianness.
We define them by default in asm-generic/io.h to access the device using
little-endian access as it is the current use, but we will be able to define
big-endian version when new architectures will use them.
Signed-off-by: Laurent Vivier <laurent@xxxxxxxxx>
Thanks for your patch!
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -906,6 +906,13 @@ static inline void iowrite64_rep(volatile void __iomem *addr,
#endif /* CONFIG_64BIT */
#endif /* CONFIG_GENERIC_IOMAP */
+#ifndef goldfish_ioread32
+#define goldfish_ioread32 ioread32
+#endif
+#ifndef goldfish_iowrite32
+#define goldfish_iowrite32 iowrite32
+#endif
+
#ifdef __KERNEL__
I've just discovered include/linux/goldfish.h, which already has gf_*()
accessors for 64-bit, so it'd make sense to move the above there,
and adjust the names.
Arnd: note that the existing ones do use __raw_writel().
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
