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

[Vlad Zolotarov <vladz@cloudius-systems.com>]

On 10/05/15 11:41, Stephen Hemminger wrote:
> On Sun,  4 Oct 2015 23:43:17 +0300
> Vlad Zolotarov <vladz@cloudius-systems.com> 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? ;)