On Thu, Apr 05, 2018 at 06:34:44PM +0200, Nicolas Morey-Chaisemartin wrote:
>
>
> On 04/05/2018 06:05 PM, Jason Gunthorpe wrote:
> > On Thu, Apr 05, 2018 at 05:40:46PM +0200, Nicolas Morey-Chaisemartin wrote:
> >>
> >> On 04/05/2018 05:20 PM, Jason Gunthorpe wrote:
> >>> On Thu, Apr 05, 2018 at 08:35:26AM +0200, Nicolas Morey-Chaisemartin wrote:
> >>>> On 04/05/2018 12:21 AM, Jason Gunthorpe wrote:
> >>>>> Is this just a userspace bug in ibstat or do roce ports actually implement umad?
> >>>>>
> >>>>> Jason
> >>>> It seems like they don't. It's just ibstat doing a umad_init()
> >>>> before making few calls to umad_get_cas_names() and a few other that
> >>>> seem to work through simple reads in sysfs (not umad related).
> >>>>
> >>>> Not sure what the clean way to fix this is. Removing the call to
> >>>> umad_init feels dirty but it's simple enough. Any ideas ?
> >>> Maybe we should make umad_init not open the umad device if the link
> >>> layer is ethernet, iwarp, etc?
> >>>
> >>> Hal?
> >>>
> >>> Jason
> >> As there may be multiple device type in the same host, I don't think it'd be that easy.
> >>
> >> Right now the only thing umad_init() is doind is checking version against the kernel ABI (or something like that).
> >> This is not required for a lot of the umad API as they only list stuff in sysfs.
> > It is not umad_init we need to remove, but umad_open_port should not
> > be called if the link layer is ethernet.
> >
> > Jason
>
> For ibstat, I don't think it is calling umad_open_port. It's only
> call to umad are umad_init, umad_get_cas_names, umad_get_ca,
> umad_get_ca_portguid and it doesn't seem like any of these call
> umad_open_port. The failure from ibstat is due to umad_init which
> fails because there is no /sys/class/infiniband_mad/abi_version as
> we only have RoCE hw and the ib_umad module is not automatically
> loaded.
Ooooh I see now.
Yes, this is structured badly.. We should make umad_init into a NOP
and learn the abi_version only when we need it.
How about this?
diff --git a/libibumad/umad.c b/libibumad/umad.c
index dcb2c6809eb12c..08efb089d990cc 100644
--- a/libibumad/umad.c
+++ b/libibumad/umad.c
@@ -90,9 +90,31 @@ static int umaddebug = 0;
static const char *def_ca_name = "mthca0";
static int def_ca_port = 1;
-static unsigned abi_version;
static unsigned new_user_mad_api;
+static unsigned int get_abi_version(void)
+{
+ static unsigned int abi_version;
+
+ if (abi_version != 0)
+ return abi_version & 0x7FFFFFFF;
+
+ if (sys_read_uint(IB_UMAD_ABI_DIR, IB_UMAD_ABI_FILE, &abi_version) <
+ 0) {
+ IBWARN("can't read ABI version from %s/%s (%m): is ib_umad module loaded?",
+ IB_UMAD_ABI_DIR, IB_UMAD_ABI_FILE);
+ abi_version = 1 << 31;
+ return 0;
+ }
+
+ if (abi_version < IB_UMAD_ABI_VERSION) {
+ abi_version = 1 << 31;
+ return 0;
+ }
+
+ return abi_version;
+}
+
/*************************************
* Port
*/
@@ -502,19 +524,6 @@ static int dev_to_umad_id(const char *dev, unsigned port)
int umad_init(void)
{
TRACE("umad_init");
- if (sys_read_uint(IB_UMAD_ABI_DIR, IB_UMAD_ABI_FILE, &abi_version) < 0) {
- IBWARN
- ("can't read ABI version from %s/%s (%m): is ib_umad module loaded?",
- IB_UMAD_ABI_DIR, IB_UMAD_ABI_FILE);
- return -1;
- }
- if (abi_version < IB_UMAD_ABI_VERSION) {
- IBWARN
- ("wrong ABI version: %s/%s is %d but library minimal ABI is %d",
- IB_UMAD_ABI_DIR, IB_UMAD_ABI_FILE, abi_version,
- IB_UMAD_ABI_VERSION);
- return -1;
- }
return 0;
}
@@ -618,9 +627,13 @@ int umad_open_port(const char *ca_name, int portnum)
{
char dev_file[UMAD_DEV_FILE_SZ];
int umad_id, fd;
+ unsigned int abi_version = get_abi_version();
TRACE("ca %s port %d", ca_name, portnum);
+ if (!abi_version)
+ return -EOPNOTSUPP;
+
if (!(ca_name = resolve_ca_name(ca_name, &portnum)))
return -ENODEV;
--
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