[lkml]   [2001]   [May]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: isa_read/write not available on ppc - solution suggestions ??
    On Tue, May 01, 2001 at 02:19:33PM -0700, Linus Torvalds wrote:
    > On Tue, 1 May 2001, Russell King wrote:
    > > Talking around this issue, is there any chance of getting the
    > > official use of the first parameter to ioremap documented in
    > > Documentation/IO-mapping.txt please? There appears to be
    > > confusion as to whether it is:
    > >
    > > a) PCI bus address
    > > b) CPU untranslated address
    > It's neither.
    > It's a cookie that you can do arithmetic off and pass on to the
    > readx/writex, and nothing more. You cannot make any assumptions at all
    > about what it means.
    > In particular, you can _not_ assume that it is a PCI bus address ("WHICH
    > bus?") and you can absolutely not assume that it is a CPU address (many
    > CPU's do not "memory map" PCI at all).

    In which case, can we change the following in IO-mapping.txt please?

    * remap framebuffer PCI memory area at 0xFC000000,
    * size 1MB, so that we can access it: We can directly
    * access only the 640k-1MB area, so anything else
    * has to be remapped.
    char * baseptr = ioremap(0xFC000000, 1024*1024);

    since its not true? (since 0xfc000000 is a cookie).

    Russell King ( The developer of ARM Linux

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 12:52    [W:4.653 / U:0.080 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site