From: Bjorn Helgaas <helgaas@xxxxxxxxxx> Date: Wed, 28 Feb 2018 17:08:29 -0600 > On Mon, Feb 19, 2018 at 10:30:25AM -0500, David Miller wrote: >> From: David Woodhouse <dwmw2@xxxxxxxxxxxxx> >> Date: Mon, 19 Feb 2018 15:24:18 +0000 >> >> >> For one, the sparc specific code allows mmap'ing any address range >> >> within a PCI bus device. The generic code does not allow that. >> > >> > >> > You mean any address range in a given PCI bus even if there is no >> > actual device with a BAR at the corresponding address? >> > >> > Would I be right to assume this was only available through the legacy >> > procfs API? I think it should be possible to accommodate it, and it >> > does look like I'd missed this requirement the first time round; thanks >> > for pointing it out. >> >> It was probably the case that only procfs could do it. >> >> It is the mechanism by which we were able to let the X server poke >> around in VGA ISA space. It does a bus I/O space map for the bus >> device above the VGA card. > > What's the bottom line? Do we want this for sparc? If so, do you > want to take it, Dave M, or would you like me to? The bottom line is that David W.'s patch would break sparc so we don't want this.
