Re: [PATCH v3 2/3] uio_pci_generic: add MSI/MSI-X support

[Vlad Zolotarov]

On 10/05/15 11:41, Stephen Hemminger wrote:
> On Sun,  4 Oct 2015 23:43:17 +0300
> Vlad Zolotarov <vladz@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > +static int setup_maps(struct pci_dev *pdev, struct uio_info *info)
> > +{
> > +	int i, m = 0, p = 0, err;
> > +	static const char * const bar_names[] = {
> > +		"BAR0",	"BAR1",	"BAR2",	"BAR3",	"BAR4",	"BAR5",
> > +	};
> > +
> > +	for (i = 0; i < ARRAY_SIZE(bar_names); i++) {
> > +		unsigned long start = pci_resource_start(pdev, i);
> > +		unsigned long flags = pci_resource_flags(pdev, i);
> > +		unsigned long len = pci_resource_len(pdev, i);
> > +
> > +		if (start == 0 || len == 0)
> > +			continue;
> > +
> > +		if (flags & IORESOURCE_MEM) {
> > +			void __iomem *addr;
> > +
> > +			if (m >= MAX_UIO_MAPS)
> > +				continue;
> > +
> > +			addr = ioremap(start, len);
> > +			if (addr == NULL) {
> > +				err = -EINVAL;
> > +				goto fail;
> > +			}
> > +
> > +			info->mem[m].name = bar_names[i];
> > +			info->mem[m].addr = start;
> > +			info->mem[m].internal_addr = addr;
> > +			info->mem[m].size = len;
> > +			info->mem[m].memtype = UIO_MEM_PHYS;
> > +			++m;
> > +		} else if (flags & IORESOURCE_IO) {
> > +			if (p >= MAX_UIO_PORT_REGIONS)
> > +				continue;
> > +
> > +			info->port[p].name = bar_names[i];
> > +			info->port[p].start = start;
> > +			info->port[p].size = len;
> > +			info->port[p].porttype = UIO_PORT_X86;
> > +			++p;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +fail:
> > +	for (i = 0; i < m; i++) {
> > +		iounmap(info->mem[i].internal_addr);
> > +		info->mem[i].internal_addr = NULL;
> > +	}
> > +
> > +	return err;
> > +
> I wonder do we really have to setup all the BAR's in uio_pci_generic?
> The DPDK code works with uio_pci_generic already, and it didn't setup the BAR's.
> One possible issue is that without that maybe kernel would not know about the
> region used for MSI-X vectors table.

So, what's your point? It sounds like u are for setting the mappings in 
the uio_pci_generic after all, aren't u? ;)


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