On Wednesday 28 May 2014 14:41:52 H. Peter Anvin wrote: > On 05/19/2014 05:36 AM, Arnd Bergmann wrote: > > > > My feeling is that all devices we can think of fall into at least one > > of these categories: > > > > * legacy PC stuff that needs only byte access > > * PCI devices that can be accessed through sysfs > > * devices on x86 that can be accessed using iopl > > > > I don't believe PCI I/O space devices can be accessed through sysfs, but > perhaps I'm wrong? (mmapping I/O space is not portable.) The interface is there, both a read/write and mmap on the resource bin_attribute. But it seems you're right, neither of them is implemented on all architectures. Only powerpc, microblaze, alpha, sparc and xtensa allow users to mmap I/O space, even though a lot of others could. The read-write interface is only defined for alpha, ia64, microblaze and powerpc. Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
