> -----Original Message----- > From: Christoph Hellwig [mailto:hch@xxxxxxxxxxxxx] > Sent: Monday, July 06, 2015 12:25 AM > To: Steve Wise > Cc: dledford@xxxxxxxxxx; sagig@xxxxxxxxxxxx; ogerlitz@xxxxxxxxxxxx; roid@xxxxxxxxxxxx; linux-rdma@xxxxxxxxxxxxxxx; > eli@xxxxxxxxxxxx; target-devel@xxxxxxxxxxxxxxx; linux-nfs@xxxxxxxxxxxxxxx; trond.myklebust@xxxxxxxxxxxxxxx; bfields@xxxxxxxxxxxx > Subject: Re: [PATCH V3 1/5] RDMA/core: Transport-independent access flags > > On Sun, Jul 05, 2015 at 06:22:00PM -0500, Steve Wise wrote: > > The semantics for MR access flags are not consistent across RDMA > > protocols. So rather than have applications try and glean what they > > need, have them pass in the intended roles and attributes for the MR to > > be allocated and let the RDMA core select the appropriate access flags > > given the roles, attributes, and device capabilities. > > > > We introduce rdma_mr_roles and rdma_mr_attributes that enumerate the > > possible roles and attributes for a MR. These are documented in the > > enums themselves. > > > > New services exported: > > > > rdma_device_access_flags() - given the intended MR roles and attributes > > passed in, return the ib_access_flags bits for the device. > > > > rdma_get_dma_mr() - allocate a dma mr using the applications intended > > MR roles and MR attributes. This uses rdma_device_access_flags(). > > > > rdma_fast_reg_access_flags() - return the ib_access_flags bits needed > > for a fast register WR given the applications intended MR roles and > > MR attributes. This uses rdma_device_access_flags(). > > > > Signed-off-by: Steve Wise <swise@xxxxxxxxxxxxxxxxxxxxx> > > --- > > > > drivers/infiniband/core/verbs.c | 30 +++++++++++ > > include/rdma/ib_verbs.h | 106 +++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 136 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c > > index bac3fb4..f42595c 100644 > > --- a/drivers/infiniband/core/verbs.c > > +++ b/drivers/infiniband/core/verbs.c > > @@ -1144,6 +1144,36 @@ struct ib_mr *ib_get_dma_mr(struct ib_pd *pd, int mr_access_flags) > > } > > EXPORT_SYMBOL(ib_get_dma_mr); > > > > +int rdma_device_access_flags(struct ib_pd *pd, int roles, int attrs) > > +{ > > + int access_flags = attrs; > > Please add an assert for the values that are allowed for attrs. > > It also would be highly useful to add a kerneldoc comment describing > the function and the parameters. Also __bitwise sparse tricks > to ensure the right flags are passed wouldn't be a too bad idea. > Can you explain the "__bitwise sparse tricks"? Or point me to an example. > > +/** > > + * rdma_mr_attributes - attributes for rdma memory regions > > + */ > > +enum { > > + RDMA_MRA_ZERO_BASED = IB_ZERO_BASED, > > + RDMA_MRA_ACCESS_ON_DEMAND = IB_ACCESS_ON_DEMAND, > > +}; > > Why not specfiy these as separate nuerical namespace? > To avoid having to translate them. > > +/** > > + * rdma_device_access_flags - Returns the device-specific MR access flags. > > + * @pd: The protection domain associated with the memory region. > > + * @roles: The intended roles of the MR > > + * @attrs: The desired attributes of the MR > > + * > > + * Use the intended roles from @roles along with @attrs and the device > > + * capabilities to generate the needed access rights. > > + * > > + * Return: the ib_access_flags value needed to allocate the MR. > > + */ > > +int rdma_device_access_flags(struct ib_pd *pd, int roles, int attrs); > > Oh, here we have kerneldoc comments, just in the wrong place. Please > move them to the function defintion. Ok. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
