linux-rdma.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Leon Romanovsky <leon@kernel.org>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Doug Ledford <dledford@redhat.com>,
	RDMA mailing list <linux-rdma@vger.kernel.org>
Subject: Re: [PATCH rdma-next 01/43] RDMA/cm: Add naive SET/GET implementations to hide CM wire format
Date: Mon, 18 Nov 2019 15:04:58 +0200	[thread overview]
Message-ID: <20191118130458.GD52766@unreal> (raw)
In-Reply-To: <20191115204558.GA22185@ziepe.ca>

On Fri, Nov 15, 2019 at 04:45:58PM -0400, Jason Gunthorpe wrote:
> On Sun, Oct 27, 2019 at 09:05:39AM +0200, Leon Romanovsky wrote:
>
> >  #define IB_CM_CLASS_VERSION	2 /* IB specification 1.2 */
> > +#define _CM_SET(p, offset, mask, value)                                        \
> > +	({                                                                     \
> > +		void *field = (u8 *)p + sizeof(struct ib_mad_hdr) + offset;    \
> > +		u8 bytes =                                                     \
> > +			DIV_ROUND_UP(__builtin_popcount(mask), BITS_PER_BYTE); \
> > +		switch (bytes) {                                               \
> > +		case 1: {                                                      \
> > +			*(u8 *)field &= ~mask;                                 \
> > +			*(u8 *)field |= FIELD_PREP(mask, value);               \
> > +		} break;                                                       \
> > +		case 2: {                                                      \
> > +			u16 val = ntohs(*(__be16 *)field) & ~mask;             \
> > +			val |= FIELD_PREP(mask, value);                        \
> > +			*(__be16 *)field = htons(val);                         \
> > +		} break;                                                       \
> > +		case 3: {                                                      \
> > +			u32 val = ntohl(*(__be32 *)field) & ~(mask << 8);      \
> > +			val |= FIELD_PREP(mask, value) << 8;                   \
> > +			*(__be32 *)field = htonl(val);                         \
>
> This doesn't work for flow label which has a 20 byte field, the <<8 is
> just a hack to fix the 24 byte case.
>
> This is also some typo's:
>
> > + #define CM_REQ_LOCAL_EECN_OFFSET 36
> > + #define CM_REQ_LOCAL_EECN_MASK GENMASK(24, 0)
>
> Should be 23, 0
>
> > + #define CM_REQ_PRIMARY_PACKET_RATE_OFFSET 91
> > + #define CM_REQ_PRIMARY_PACKET_RATE_MASK GENMASK(3, 2)
>
> Packet rate is a 6 bit field, not a 2 bit field
>
> I only looked at REQ. I assume all the others have a similar error
> rate.
>
> Overall, I don't like this approach. The macros are messy/buggy and
> there isn't a clear mapping of the data in the tables to the C code.
>
> How about this instead:

I very liked type safety in your solution, but I think that IBA_FIELD*_LOC()
macros add too much magic into such simple thing like spec declarations.

I'll update, recheck and resend.

Thanks

  reply	other threads:[~2019-11-18 13:05 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-27  7:05 [PATCH rdma-next 00/43] Convert CM to bitmaps Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 01/43] RDMA/cm: Add naive SET/GET implementations to hide CM wire format Leon Romanovsky
2019-11-15 20:45   ` Jason Gunthorpe
2019-11-18 13:04     ` Leon Romanovsky [this message]
2019-11-18 13:43       ` Jason Gunthorpe
2019-10-27  7:05 ` [PATCH rdma-next 02/43] RDMA/cm: Request For Communication (REQ) message definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 03/43] RDMA/cm: Message Receipt Acknowledgment (MRA) " Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 04/43] RDMA/cm: Reject (REJ) " Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 05/43] RDMA/cm: Reply To Request for communication (REP) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 06/43] RDMA/cm: Ready To Use (RTU) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 07/43] RDMA/cm: Request For Communication Release (DREQ) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 08/43] RDMA/cm: Reply To Request For Communication Release (DREP) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 09/43] RDMA/cm: Load Alternate Path (LAP) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 10/43] RDMA/cm: Alternate Path Response (APR) message definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 11/43] RDMA/cm: Service ID Resolution Request (SIDR_REQ) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 12/43] RDMA/cm: Service ID Resolution Response (SIDR_REP) definitions Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 13/43] RDMA/cm: Convert QPN and EECN to be u32 variables Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 14/43] RDMA/cm: Convert REQ responded resources to the new scheme Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 15/43] RDMA/cm: Convert REQ initiator depth " Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 16/43] RDMA/cm: Convert REQ remote response timeout Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 17/43] RDMA/cm: Simplify QP type to wire protocol translation Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 18/43] RDMA/cm: Convert REQ flow control Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 19/43] RDMA/cm: Convert starting PSN to be u32 variable Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 20/43] RDMA/cm: Update REQ local response timeout Leon Romanovsky
2019-10-27  7:05 ` [PATCH rdma-next 21/43] RDMA/cm: Convert REQ retry count to use new scheme Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 22/43] RDMA/cm: Update REQ path MTU field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 23/43] RDMA/cm: Convert REQ RNR retry timeout counter Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 24/43] RDMA/cm: Convert REQ MAX CM retries Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 25/43] RDMA/cm: Convert REQ SRQ field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 26/43] RDMA/cm: Convert REQ flow label field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 27/43] RDMA/cm: Convert REQ packet rate Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 28/43] RDMA/cm: Convert REQ SL fields Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 29/43] RDMA/cm: Convert REQ subnet local fields Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 30/43] RDMA/cm: Convert REQ local ack timeout Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 31/43] RDMA/cm: Convert MRA MRAed field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 32/43] RDMA/cm: Convert MRA service timeout Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 33/43] RDMA/cm: Update REJ struct to use new scheme Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 34/43] RDMA/cm: Convert REP target ack delay field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 35/43] RDMA/cm: Convert REP failover accepted field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 36/43] RDMA/cm: Convert REP flow control field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 37/43] RDMA/cm: Convert REP RNR retry count field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 38/43] RDMA/cm: Convert REP SRQ field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 39/43] RDMA/cm: Delete unused CM LAP functions Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 40/43] RDMA/cm: Convert LAP flow label field Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 41/43] RDMA/cm: Convert LAP fields Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 42/43] RDMA/cm: Delete unused CM ARP functions Leon Romanovsky
2019-10-27  7:06 ` [PATCH rdma-next 43/43] RDMA/cm: Convert SIDR_REP to new scheme Leon Romanovsky

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191118130458.GD52766@unreal \
    --to=leon@kernel.org \
    --cc=dledford@redhat.com \
    --cc=jgg@ziepe.ca \
    --cc=linux-rdma@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).