Messages in this thread | | | Date | Fri, 5 Mar 1999 11:11:11 -0700 (MST) | From | Vassili Leonov <> | Subject | Re: user space writel() etc. in 2.2.2 |
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On 5 Mar 1999, Jes Sorensen wrote:
> Alan> thats really going to work well from user space. The moment you > Alan> go digging into devices directly from user space you lose > Alan> portability. You loose portability because there is no writel() defined in 2.2 (since 2.13). Somehow that was not the case under 2.0. I think this needs to be addressed. The simple way is to add writel() etc. to <asm/io.h>.
Besides, why i386/io.h does not know anything about writel() in non __KERNEL__ , whereas alpha/io.h declares them as extern. That sure is inconsitent.
On the other hand - WHY one loses portability doing IO memory access on different architectures? Sure enough that PCI memory would be present on any architecture that has that PCI plugged in, and registers would be the same (though ordering might differ, and that is the responsibility of writel() etc. to handle it. > > Hmmm, good point - I wonder how the XFree people solved this for the > Alpha X servers. Well, how does this fit with the point that user space IO memeory access is bad? Sure enough X11 is all based on this "bad" concept.
On a side note, for hacking hardware I always missed MSDOS like debug in Linux. As soon as I implemented tcl extension to that effect it is broken in 2.0 to 2.2 transition.
#------------------------------------# | Linux Media Labs LLC | Vassili Leonov #------------------------------------# mailto:vleo@linuxmedialabs.com http://linuxmedialabs.com phone:1-719-231-3173
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