Messages in this thread | | | From | Andy Shevchenko <> | Date | Tue, 20 Feb 2018 16:33:45 +0200 | Subject | Re: [PATCH v14 1/9] LIB: Introduce a generic PIO mapping method |
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On Mon, Feb 19, 2018 at 7:48 PM, John Garry <john.garry@huawei.com> wrote: > From: Zhichang Yuan <yuanzhichang@hisilicon.com> > > In commit 41f8bba7f555 ("of/pci: Add pci_register_io_range() and > pci_pio_to_address()"), a new I/O space management was supported. With > that driver, the I/O ranges configured for PCI/PCIe hosts on some > architectures can be mapped to logical PIO, converted easily between > CPU address and the corresponding logicial PIO. Based on this, PCI > I/O devices can be accessed in a memory read/write way through the > unified in/out accessors. > > But on some archs/platforms, there are bus hosts which access I/O > peripherals with host-local I/O port addresses rather than memory > addresses after memory-mapped. > > To support those devices, a more generic I/O mapping method is introduced > here. Through this patch, both the CPU addresses and the host-local port > can be mapped into the logical PIO space with different logical/fake PIOs. > After this, all the I/O accesses to either PCI MMIO devices or host-local > I/O peripherals can be unified into the existing I/O accessors defined in > asm-generic/io.h and be redirected to the right device-specific hooks > based on the input logical PIO.
> +#define PIO_INDIRECT 0x01UL /* indirect IO flag */ > +#define PIO_CPU_MMIO 0x00UL /* memory mapped io flag */
It looks like bitfield, but from use I don't see it.
Perhaps use enum instead?
> + resource_size_t hwaddr = -1;
> +unsigned long > + return -1; > + return -1;
> +unsigned long > + return -1;
> +type logic_in##bw(unsigned long addr) \ > + type ret = -1; \
All types above are unsigned. I'm not sure it's the best approach to use -1 implicitly casted to unsigned type.
I would rather use ~0UL or alike.
-- With Best Regards, Andy Shevchenko
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