Hi, Arnd, On 2016年09月14日 22:23, Arnd Bergmann wrote: > On Wednesday, September 14, 2016 10:16:28 PM CEST zhichang.yuan wrote: >>> >>> No need to guard includes with an #ifdef. >> If remove #ifdef here, extio.h should not contain any function external declarations whose definitions are in >> extio.c compiled only when CONFIG_ARM64_INDIRECT_PIO is yes. > > There is no problem with making declarations visible for functions that > are not part of the kernel, we do that all the time. > >>>> +#define BUILDS_RW(bwl, type) \ >>>> +static inline void reads##bwl(const volatile void __iomem *addr, \ >>>> + void *buffer, unsigned int count) \ >>>> +{ \ >>>> + if (count) { \ >>>> + type *buf = buffer; \ >>>> + \ >>>> + do { \ >>>> + type x = __raw_read##bwl(addr); \ >>>> + *buf++ = x; \ >>>> + } while (--count); \ >>>> + } \ >>>> +} \ >>>> + \ >>>> +static inline void writes##bwl(volatile void __iomem *addr, \ >>>> + const void *buffer, unsigned int count) \ >>>> +{ \ >>>> + if (count) { \ >>>> + const type *buf = buffer; \ >>>> + \ >>>> + do { \ >>>> + __raw_write##bwl(*buf++, addr); \ >>>> + } while (--count); \ >>>> + } \ >>>> +} >>>> + >>>> +BUILDS_RW(b, u8) >>> >>> Why is this in here? >> the readsb/writesb are defined in asm-generic/io.h which is included later, but the redefined insb/outsb need >> to call them. Without these readsb/writesb definition before insb/outsb redefined, compile error occur. >> >> It seems that copy all the definitions of "asm-generic/io.h" is not a good idea, so I move the definitions of >> those function needed here.... >> >> Ok. I think your idea below defining in(s)/out(s) in a c file can solve this issue. >> >> #ifdef CONFIG_ARM64_INDIRECT_PIO >> #define inb inb >> extern u8 inb(unsigned long addr); >> >> #define outb outb >> extern void outb(u8 value, unsigned long addr); >> >> #define insb insb >> extern void insb(unsigned long addr, void *buffer, unsigned int count); >> >> #define outsb outsb >> extern void outsb(unsigned long addr, const void *buffer, unsigned int count); >> #endif >> >> and definitions of all these functions are in extio.c : >> >> u8 inb(unsigned long addr) >> { >> if (!arm64_extio_ops || arm64_extio_ops->start > addr || >> arm64_extio_ops->end < addr) >> return readb(PCI_IOBASE + addr); >> else >> return arm64_extio_ops->pfin ? >> arm64_extio_ops->pfin(arm64_extio_ops->devpara, >> addr + arm64_extio_ops->ptoffset, NULL, >> sizeof(u8), 1) : -1; >> } >> ..... > > Yes, sounds good. > >>>> @@ -149,6 +185,60 @@ static inline u64 __raw_readq(const volatile void __iomem *addr) >>>> #define IO_SPACE_LIMIT (PCI_IO_SIZE - 1) >>>> #define PCI_IOBASE ((void __iomem *)PCI_IO_START) >>>> >>>> + >>>> +/* >>>> + * redefine the in(s)b/out(s)b for indirect-IO. >>>> + */ >>>> +#define inb inb >>>> +static inline u8 inb(unsigned long addr) >>>> +{ >>>> +#ifdef CONFIG_ARM64_INDIRECT_PIO >>>> + if (arm64_extio_ops && arm64_extio_ops->start <= addr && >>>> + addr <= arm64_extio_ops->end) >>>> + return extio_inb(addr); >>>> +#endif >>>> + return readb(PCI_IOBASE + addr); >>>> +} >>>> + >>> >>> Looks ok, but you only seem to do this for the 8-bit >>> accessors, when it should be done for 16-bit and 32-bit >>> ones as well for consistency. >> Hip06 LPC only support 8-bit I/O operations on the designated port. > > That is an interesting limitation. Maybe still call the extio operations > and have them do WARN_ON_ONCE() instead? > > If you get a driver that calls inw/outw on the range that is owned > by the LPC bus, you otherwise get an unhandled page fault in kernel > space, which is not as nice. > Yes. It probably cause kernel panic. Will define the extio operations for other IO length and add the corresponding WARNINGS. Best, Zhichang >>>> diff --git a/drivers/bus/extio.c b/drivers/bus/extio.c >>>> new file mode 100644 >>>> index 0000000..1e7a9c5 >>>> --- /dev/null >>>> +++ b/drivers/bus/extio.c >>>> @@ -0,0 +1,66 @@ >>> >>> This is in a globally visible directory >>> >>>> + >>>> +struct extio_ops *arm64_extio_ops; >>> >>> But the identifier uses an architecture specific prefix. Either >>> move the whole file into arch/arm64, or make the naming so that >>> it can be used for everything. >> >> I perfer to move the whole file into arch/arm64, extio.h will be moved to arch/arm64/include/asm; > > Ok, that simplifies it a lot, you can just do everything in asm/io.h then. > > Arnd > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html