Re: [PATCH v1 1/3] ARM64 LPC: indirect ISA PORT IO introduced

Arnd Bergmann
2015-12-29T14:36:28Z

On Tuesday 29 December 2015 22:26:27 Rongrong Zou wrote:
> 在 2015/12/29 21:47, Arnd Bergmann 写道:
> > On Tuesday 29 December 2015 21:33:50 Rongrong Zou wrote:
> >> Indirect ISA port I/O accessing introduced, vendors can hook
> >> their own in/out function to general inb/outb. Drivers can access
> >> legacy ISA I/O port by inb/outb as it is done in x86 platform.
> >>
> >> Signed-off-by: Rongrong Zou <zourongrong@gmail.com>
> >
> > Looks correct to me, but I have a few style comments
> >
> >> ---
> >> arch/arm64/Kconfig.platforms | 5 ++-
> >> arch/arm64/include/asm/io.h | 78 ++++++++++++++++++++++++++++++++++++++++++++
> >> arch/arm64/kernel/setup.c | 5 +++
> >> 3 files changed, 87 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/arch/arm64/Kconfig.platforms b/arch/arm64/Kconfig.platforms
> >> index 4043c35..98ae206 100644
> >> --- a/arch/arm64/Kconfig.platforms
> >> +++ b/arch/arm64/Kconfig.platforms
> >> @@ -127,5 +127,8 @@ config ARCH_ZYNQMP
> >> bool "Xilinx ZynqMP Family"
> >> help
> >> This enables support for Xilinx ZynqMP Family
> >> -
> >> +config ARM64_INDIRECT_PIO
> >> + bool "ARM64 Indirect port I/O"
> >> + help
> >> + This enables support for ARM64 indirect port I/O
> >> endmenu
> >
> > The option should probably go into arch/arm64/Kconfig. Possibly you can make
> > it a silent option that just gets selected whenever a driver is enabled
> > that might set the callbacks.
>
> I try to bind it with HISILICON platform.

It should be possible to build the actual driver on all platforms, at
least with COMPILE_TEST.

> >> diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
> >> index 44be1e0..0041f3b 100644
> >> --- a/arch/arm64/include/asm/io.h
> >> +++ b/arch/arm64/include/asm/io.h
> >> @@ -193,6 +193,84 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
> >> */
> >> #define xlate_dev_kmem_ptr(p) p
> >>
> >> +#ifdef CONFIG_ARM64_INDIRECT_PIO
> >> +#define DEF_PCI_HOOK_pio(x) x
> >> +#else
> >> +#define DEF_PCI_HOOK_pio(x) NULL
> >> +#endif
> >
> > Maybe just put the entire definition block inside #ifdef and
> > fall back to the default inb/outb definitions otherwise.
> >
> >> +/*
> >> + * This value is equal to PCIBIOS_MIN_IO
> >> + */
> >> +#define LEGACY_ISA_PORT_MAX 0x1000
> >
> > I would just use PCIBIOS_MIN_IO instead of defining another macro.
>
> Because PCIBIOS_MIN_IO is defined in asm/pci.h, and asm/io.h
> is included by asm/pci.h. so do you mean i define PCIBIOS_MIN_IO here,
> and in asm/pci.h just use include asm/io.h ?

Yes, I guess that would work.

Arnd