Re: Fwd: Re: [PATCH] PCI I/O space

  • From: Robert Millan <rmh@xxxxxxxxxxx>
  • To: pooka@xxxxxx, rumpkernel-users@xxxxxxxxxxxxx
  • Date: Sun, 14 Jun 2015 15:57:51 +0200

El 14/06/15 a les 14:05, Antti Kantee ha escrit:

On 14/06/15 11:54, Robert Millan wrote:

Thanks Antti. Here's the new patchset.

Almost there. Still small nits:

#ifdef RUMP_PCI_IOSPACE
- pba.pba_flags |= PCI_FLAGS_IO_OKAY;
+#ifdef rumpcomp_pci_initiopl
+ error = rumpcomp_pci_initiopl();
+ if (error == 0) {
+ pba.pba_flags |= PCI_FLAGS_IO_OKAY;
+ } else {
+ aprint_error("pci: unable to raise I/O privilege level (error %d), direct
I/O will be unavailable\n", error);
+ }
+#endif
#endif

The print still doesn't match the call. How do you know at that abstraction level that
initiopl() will exactly "raise I/O privilege level"?

Well that's what "iopl" stands for! Perhaps we should pick another name? :-)

Btw, iopl() is a Linux-ism. An x86-ism even, IIRC. For example the FreeBSD/x86 way is
open("/dev/io"). Maybe use something more generic like:

rumpcomp_pci_initio()

?

Also, do we still need RUMP_PCI_IOSPACE? Or can we say that everything
providing iospace access must now define rumpcomp_pci_initiopl?

A rumpcomp_pci_initiopl() dummy stub is cheap, seems reasonable to assume it's
present.

--
--
Robert Millan

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