> -----Original Message-----
> From: bart.vanass...@gmail.com [mailto:bart.vanass...@gmail.com] On
> Behalf Of Bart Van Assche
> Sent: Monday, August 15, 2011 7:32 AM
> To: rpear...@systemfabricworks.com
> Cc: linux-rdma@vger.kernel.org
> Subject: Re: [patch v2 12/37] add rxe_verbs.h
>
> On Sun, Jul 24, 2011 at 9:43 PM, <rpear...@systemfabricworks.com> wrote:
> > +static inline int pkey_match(u16 key1, u16 key2)
> > +{
> > + return (((key1 & 0x7fff) != 0) &&
> > + ((key1 & 0x7fff) == (key2 & 0x7fff)) &&
> > + ((key1 & 0x8000) || (key2 & 0x8000))) ? 1 : 0;
> > +}
>
> Shouldn't the return type of the above function be "bool" instead of
> "int" ? Also, the "? 1 : 0" part at the end of the above expression
> looks superfluous to me.
Sounds fine to me.
>
> > +
> > +/* Return >0 if psn_a > psn_b
> > + * 0 if psn_a == psn_b
> > + * <0 if psn_a < psn_b
> > + */
> > +static inline int psn_compare(u32 psn_a, u32 psn_b)
> > +{
> > + s32 diff;
> > + diff = (psn_a - psn_b) << 8;
> > + return diff;
> > +}
Sure
>
> Mentioning in the comment block that (according to IBTA) PSNs are
> 24-bit quantities would help IMHO.
>
> > +#define RXE_LL_ADDR_LEN (16)
> > +
> > +struct rxe_av {
> > + struct ib_ah_attr attr;
> > + u8 ll_addr[RXE_LL_ADDR_LEN];
> > +};
Good idea. Can use MAX_ADDR_LEN as well.
>
> Since the ib_rxe kernel module can be used in combination with other
> network drivers than only Ethernet drivers, the number of bytes stored
> in ll_addr[] by init_av() depends on the link layer type. Shouldn't
> the address length be stored in this structure too ?
>
> > +/* must match corresponding data structure in librxe */
> > +struct rxe_send_wqe {
> > + struct ib_send_wr ibwr;
> > + struct rxe_av av; /* UD only */
> > + u32 status;
> > + u32 state;
> > + u64 iova;
> > + u32 mask;
> > + u32 first_psn;
> > + u32 last_psn;
> > + u32 ack_length;
> > + u32 ssn;
> > + u32 has_rd_atomic;
> > + struct rxe_dma_info dma; /* must go last */
> > +};
>
> Can't librxe use this header file instead of duplicating the above
definition ?
We followed the local convention which is to keep the header files separate.
(See e.g. nes/nes_user.h, mthca/mthca_user.h, etc...) I can't justify it
except that everyone else does it too.
>
> > +struct rxe_port {
> > + struct ib_port_attr attr;
> > + u16 *pkey_tbl;
> > + __be64 *guid_tbl;
> > + __be64 subnet_prefix;
> > +
> > + /* rate control */
> > + /* TODO */
> > +
> > + spinlock_t port_lock;
> > +
> > + unsigned int mtu_cap;
> > +
> > + /* special QPs */
> > + u32 qp_smi_index;
> > + u32 qp_gsi_index;
> > +};
>
> Regarding the "to do" item above: is rate control something planned
> for the first submission of this driver ?
Currently rxe only supports one port per device and the injection rate
control is tied to the device. It is a fairly fussy change to completely
implement multiport devices and doesn't add much value as far as I can tell.
So for now I suppose we can drop this TODO.
>
> Bart.
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