On 10/05/15 12:08, Vlad Zolotarov wrote:
On 10/05/15 11:41, Stephen Hemminger wrote:
On Sun, 4 Oct 2015 23:43:17 +0300
Vlad Zolotarov <vl...@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.
DPDK never used uio_pci_generic with MSI-X support so far and all
MSI-X capable UIO DPDK drivers like igb_uio and your newly proposed
uio_msi do map them all.
U also mentioned in the other thread that virtio requires portio bars
too.
The thing is that generally bars are needed for programming the device
therefore it's logical to have them exposed. In general different
devices have different registers layout therefore a general driver may
not know which bar exactly is going to be required for a specific
device and for a specific usage. That's why I think that "map them
all" approach is rather generic and appropriate. However if there are
other motives not to do so that I'm missing, pls., let me know.
Having said all that however I'd agree if someone would say that
mappings setting would rather come as a separate patch in this series... ;)
it will in v4...
thanks,
vlad
One possible issue is that without that maybe kernel would not know
about the
region used for MSI-X vectors table.
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