Hi Michael,
On Sun, Jun 6, 2021 at 7:28 AM Michael Schmitz <schmitzmic@xxxxxxxxx> wrote:
Current io_mm.h uses address translation and ROM port IO primitives when
port addresses are below 1024, and raw untranslated MMIO IO primitives
else when CONFIG_ATARI_ROM_ISA is set. This is done regardless of the
m68k machine type a multi-platform kernel runs on. As a consequence,
the Q40 IDE driver in multiplatform kernels cannot work.
Conversely, the Atari IDE driver uses wrong address translation if a
multiplatform Q40 and Atari kernel does _not_ set CONFIG_ATARI_ROM_ISA.
Replace MMIO by ISA IO primitives for addresses > 1024 (if isa_type
is ISA_TYPE_ENEC), and change the ISA address translation used for
Atari to a no-op for those addresses.
Switch readb()/writeb() and readw()/writew() to their ISA equivalents
also. Change the address translation functions to return the identity
translation if CONFIG_ATARI_ROM_ISA is not defined, and set MULTI_ISA
for kernels where Q40 and Atari are both configured so this can actually
work (isa_type set to Q40 at compile time else).
Thanks for your patch!
Fixes: 84b16b7b0d5c818fadc731a69965dc76dce0c91e
Fixes: 84b16b7b0d5c818f ("m68k/atari: ROM port ISA adapter support")
Hint:
$ git help fixes
'fixes' is aliased to 'show --format='Fixes: %h ("%s")' -s'
$ git fixes 84b16b7b0d5c818fadc731a69965dc76dce0c91e
Fixes: 84b16b7b0d5c818f ("m68k/atari: ROM port ISA adapter support")
Signed-off-by: Michael Schmitz <schmitzmic@xxxxxxxxx>
--- a/arch/m68k/include/asm/io_mm.h
+++ b/arch/m68k/include/asm/io_mm.h
@@ -113,7 +117,7 @@
#ifdef MULTI_ISA
extern int isa_type;
-extern int isa_sex;
+extern int isa_sex; /* Atari relies on this to be zero-initialized */
Shouldn't that comment be next to its definition in
arch/m68k/kernel/setup_mm.c?
@@ -135,9 +139,11 @@ static inline u8 __iomem *isa_itb(unsigned long addr)
case ISA_TYPE_AG: return (u8 __iomem *)AG_ISA_IO_B(addr);
#endif
#ifdef CONFIG_ATARI_ROM_ISA
- case ISA_TYPE_ENEC: return (u8 __iomem *)ENEC_ISA_IO_B(addr);
+ case ISA_TYPE_ENEC: if (addr < 1024)
+ return (u8 __iomem *)ENEC_ISA_IO_B(addr);
+ fallthrough; /* not ROM port? fallback below! */
#endif
- default: return NULL; /* avoid warnings, just in case */
+ default: return (u8 __iomem *)(addr); /* avoid warnings, just in case */
}
Moving the default out of the switch() statement, as suggested by Finn,
would make this more future-proof, as any case (not just the last one)
can fall through to the default, using break.
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
