Hi David,

Thank you for reviewing this.

On 9/9/2016 5:06 PM, David Marchand wrote:

Hello Jianfeng,

On Thu, Sep 1, 2016 at 4:16 AM, Jianfeng Tan [off-list ref] wrote:

quoted

Previously in igb_uio, iomem is mapped, and both ioport and io mem
are recorded into uio framework, which is duplicated and makes the
code too complex.

For iomem, DPDK user space code never opens or reads files under
/sys/pci/bus/devices/xxxx:xx:xx.x/uio/uioY/maps/. Instead,
/sys/pci/bus/devices/xxxx:xx:xx.x/resourceY are used to map device
memory.

For ioport, non-x86 platforms cannot read from files under
/sys/pci/bus/devices/xxxx:xx:xx.x/uio/uioY/portio/ directly, because
non-x86 platforms need to map port region for access in user space,
see non-x86 version pci_uio_ioport_map(). x86 platforms can use the
the same way as uio_pci_generic.

This patch deprecates iomem and ioport mapping in igb_uio kernel
module, and adjusts the iomem implementation in both igb_uio and
uio_pci_generic:
   - for x86 platform, get ports info from /proc/ioports;
   - for non-x86 platform, map and get ports info by pci_uio_ioport_map().

Note: this will affect those applications who are using files under
/sys/pci/bus/devices/xxxx:xx:xx.x/uio/uioY/maps/ and
/sys/pci/bus/devices/xxxx:xx:xx.x/uio/uioY/portio/.

Signed-off-by: Jianfeng Tan <redacted>
---
  lib/librte_eal/linuxapp/eal/eal_pci.c     |   4 -
  lib/librte_eal/linuxapp/eal/eal_pci_uio.c |  56 +-------------
  lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 119 ++----------------------------
  3 files changed, 9 insertions(+), 170 deletions(-)

[snip]

quoted

diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
index 1786b75..28d09ed 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c

[snip]

quoted

-       /* FIXME only for primary process ? */
-       if (dev->intr_handle.type == RTE_INTR_HANDLE_UNKNOWN) {
-
-               snprintf(filename, sizeof(filename), "/dev/uio%u", uio_num);
-               dev->intr_handle.fd = open(filename, O_RDWR);
-               if (dev->intr_handle.fd < 0) {
-                       RTE_LOG(ERR, EAL, "Cannot open %s: %s\n",
-                               filename, strerror(errno));
-                       return -1;
-               }
-               dev->intr_handle.type = RTE_INTR_HANDLE_UIO;
-       }

The only potential issue I can see removing this is that if a device
has no iomem resource, then its interrupt fd will never be
initialised.

I'm catching it completely. IMO, dev->intr_handle.fd will be bound to be 
initialized in pci_uio_alloc_resource() <- pci_uio_map_resource() <- 
rte_eal_pci_map_device() after this patch, just like what we've done 
with uio-pci-generic. Or I'm missing something?

I can see no problem at the moment, so let's go with this.
If such a problem arises later, we can separate this from the resource
mapping stuff (with a new api ?).
The rest looks good to me.

As Ferruh said, this should go through deprecation notices then go in 17.02.

Yes, no problem.

Thanks,
Jianfeng