From: "Guan Xuetao" <gxt@mprc.pku.edu.cn>
To: "'Arnd Bergmann'" <arnd@arndb.de>
Cc: <linux-kernel@vger.kernel.org>, <linux-arch@vger.kernel.org>,
        "'Greg KH'" <greg@kroah.com>
References: <014d01cbcdae$091bc6d0$1b535470$@mprc.pku.edu.cn> <201102171814.29081.arnd@arndb.de>
In-Reply-To: <201102171814.29081.arnd@arndb.de>
Subject: RE: [PATCH 06/12] unicore32 additional architecture files: low-level lib: misc
Date: Tue, 22 Feb 2011 18:54:59 +0800
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> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@arndb.de]
> Sent: Friday, February 18, 2011 1:14 AM
> To: Guan Xuetao
> Cc: linux-kernel@vger.kernel.org; linux-arch@vger.kernel.org; 'Greg KH'
> Subject: Re: [PATCH 06/12] unicore32 additional architecture files: low-level lib: misc
> 
> On Wednesday 16 February 2011, Guan Xuetao wrote:
> > diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h
> > new file mode 100644
> > index 0000000..d73457c
> > --- /dev/null
> > +++ b/arch/unicore32/include/asm/io.h
> > @@ -0,0 +1,52 @@
> > +/*
> > + * linux/arch/unicore32/include/asm/io.h
> > + *
> > + * Code specific to PKUnity SoC and UniCore ISA
> > + *
> > + * Copyright (C) 2001-2010 GUAN Xue-tao
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +#ifndef __UNICORE_IO_H__
> > +#define __UNICORE_IO_H__
> > +
> > +#ifdef __KERNEL__
> > +
> > +#include <asm/byteorder.h>
> > +#include <asm/memory.h>
> > +#include <asm/system.h>
> > +
> > +#include <asm-generic/io.h>
> > +
> 
> I just realized that the generic io.h implementation is actually wrong here, because it does
> not offset the PIO port numbers with the PCI I/O range. To get this right, you need
> the patch below, and also need to define PCI_IOBASE appropriately.
> 
> 	Arnd
> 8<-------
> asm-generic: fix inX/outX functions for architectures that have PCI
> 
> The definitions for the PC-style PIO functions in asm-generic/io.h were
> meant as dummies so you could compile code on architectures without
> ISA and PCI buses. However, unicore32 actually wants to use them
> with a real PCI bus, so they need to be defined to actually address
> the register window holding the I/O ports.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
> index 4644c9a..e0ffa3d 100644
> --- a/include/asm-generic/io.h
> +++ b/include/asm-generic/io.h
> @@ -94,6 +94,10 @@ static inline void __raw_writeq(u64 b, volatile void __iomem *addr)
>  #define writeq(b,addr) __raw_writeq(__cpu_to_le64(b),addr)
>  #endif
> 
> +#ifndef PCI_IOBASE
> +#define PCI_IOBASE ((void __iomem *) 0)
> +#endif
> +
>  /*****************************************************************************/
>  /*
>   * traditional input/output functions
> @@ -101,32 +105,32 @@ static inline void __raw_writeq(u64 b, volatile void __iomem *addr)
> 
>  static inline u8 inb(unsigned long addr)
>  {
> -	return readb((volatile void __iomem *) addr);
> +	return readb(addr + PCI_IOBASE);
>  }
> 
>  static inline u16 inw(unsigned long addr)
>  {
> -	return readw((volatile void __iomem *) addr);
> +	return readw(addr + PCI_IOBASE);
>  }
> 
>  static inline u32 inl(unsigned long addr)
>  {
> -	return readl((volatile void __iomem *) addr);
> +	return readl(addr + PCI_IOBASE);
>  }
> 
>  static inline void outb(u8 b, unsigned long addr)
>  {
> -	writeb(b, (volatile void __iomem *) addr);
> +	writeb(b, addr + PCI_IOBASE);
>  }
> 
>  static inline void outw(u16 b, unsigned long addr)
>  {
> -	writew(b, (volatile void __iomem *) addr);
> +	writew(b, addr + PCI_IOBASE);
>  }
> 
>  static inline void outl(u32 b, unsigned long addr)
>  {
> -	writel(b, (volatile void __iomem *) addr);
> +	writel(b, addr + PCI_IOBASE);
>  }
> 
>  #define inb_p(addr)	inb(addr)
> @@ -213,32 +217,32 @@ static inline void outsl(unsigned long addr, const void *buffer, int count)
> 
>  static inline void readsl(const void __iomem *addr, void *buf, int len)
>  {
> -	insl((unsigned long)addr, buf, len);
> +	insl(addr - PCI_IOBASE, buf, len);
>  }
> 
>  static inline void readsw(const void __iomem *addr, void *buf, int len)
>  {
> -	insw((unsigned long)addr, buf, len);
> +	insw(addr - PCI_IOBASE, buf, len);
>  }
> 
>  static inline void readsb(const void __iomem *addr, void *buf, int len)
>  {
> -	insb((unsigned long)addr, buf, len);
> +	insb(addr - PCI_IOBASE, buf, len);
>  }
> 
>  static inline void writesl(const void __iomem *addr, const void *buf, int len)
>  {
> -	outsl((unsigned long)addr, buf, len);
> +	outsl(addr - PCI_IOBASE, buf, len);
>  }
> 
>  static inline void writesw(const void __iomem *addr, const void *buf, int len)
>  {
> -	outsw((unsigned long)addr, buf, len);
> +	outsw(addr - PCI_IOBASE, buf, len);
>  }
> 
>  static inline void writesb(const void __iomem *addr, const void *buf, int len)
>  {
> -	outsb((unsigned long)addr, buf, len);
> +	outsb(addr - PCI_IOBASE, buf, len);
>  }
> 
>  #ifndef CONFIG_GENERIC_IOMAP
> @@ -269,8 +273,9 @@ static inline void writesb(const void __iomem *addr, const void *buf, int len)
>  	outsl((unsigned long) (p), (src), (count))
>  #endif /* CONFIG_GENERIC_IOMAP */
> 
> -
> -#define IO_SPACE_LIMIT 0xffffffff
> +#ifndef IO_SPACE_LIMIT
> +#define IO_SPACE_LIMIT 0xffff
> +#endif
> 
>  #ifdef __KERNEL__
> 
Thanks Arnd.
It simples the life for iomapping PCI legacy space. And it looks good to me.
I apply the patch  at the top of my repo.

Guan Xuetao


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