Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | Re: [PATCH 05/32] lib: devres: don't enclose pcim_*() functions in CONFIG_HAS_IOPORT | Date | Tue, 12 Feb 2013 22:36:37 +0000 |
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On Tuesday 12 February 2013, Thomas Petazzoni wrote: > > Any driver that requires a > > linear mapping of I/O ports to __iomem pointers must depend > > CONFIG_HAS_IOPORT with the current definition of that symbol (as > > mentioned before, we should really rename that to > > CONFIG_HAS_IOPORT_MAP). Having these functions not defined is a > > compile time check that is necessary to ensure that all drivers have > > the correct annotation. > > I have the feeling that the problem is more complex than that. My > understanding is that the pcim_iomap_regions() function used by > drivers/ata/libata-sff.c can perfectly be used to map memory BARs, and > not necessarily I/O BARs. Therefore, this driver can perfectly be used > in an architecture where CONFIG_NO_IOPORT is selected.
That is correct.
> The thing is that pcim_iomap_regions() transparently allows to remap an > I/O BAR is such a BAR is passed as argument, or a memory BAR if such a > BAR is passed as argument. > > Therefore, I continue to believe that the pcim_*() functions are useful > even if the platform doesn't have CONFIG_HAS_IOPORT.
Yes, the pcim_ functions are useful in principle, but it falls back to the __pci_ioport_map() for IORESOURCE_IO, and that needs to return an error if CONFIG_HAS_IOPORT is not set. I think it would be correct if you add this hunk:
diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c index 0d83ea8..f9b6387 100644 --- a/lib/pci_iomap.c +++ b/lib/pci_iomap.c @@ -33,7 +33,7 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) return NULL; if (maxlen && len > maxlen) len = maxlen; - if (flags & IORESOURCE_IO) + if (IS_ENABLED(CONFIG_HAS_IOPORT) && (flags & IORESOURCE_IO)) return __pci_ioport_map(dev, start, len); if (flags & IORESOURCE_MEM) { if (flags & IORESOURCE_CACHEABLE) in order to prevent a link error when CONFIG_HAS_IOPORT is unset.
Arnd
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