From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Smart Subject: [PATCH] scsi_lib_dma.c : fix bug w/ dma maps on virtual fc ports Date: Tue, 7 Oct 2008 09:35:18 -0400 Message-ID: <1223386518.3082.9.camel@ogier> Reply-To: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from emulex.emulex.com ([138.239.112.1]:33471 "EHLO emulex.emulex.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753548AbYJGNfQ (ORCPT ); Tue, 7 Oct 2008 09:35:16 -0400 Received: from xcm.ad.emulex.com (xcm.emulex.com [138.239.112.69]) by emulex.emulex.com (8.13.6/8.13.6) with ESMTP id m97DZFKV025164 for ; Tue, 7 Oct 2008 06:35:15 -0700 (PDT) Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org =EF=BB=BFWhen the updated scsi dma code was introduced recently, it ass= umed the physical host/adapter was the parent of the scsi host. Unfortunately, on FC virtual ports, the parent of the scsi host is the virtual port, which does not have dma information. I have updated the dma map routines to use a function that finds the top-most scsi host, then use the parent of that host. This is a bit ugly as every dma request does this walking, to the top of the object tree. A different option that was considered was taking the parent dev, then walking the dev list backward to find the first device with a dma mask, then using that device. Eg: while (!dev->dma_mask) dev=3Ddev->parent; If there is a better solution, please let me know. -- james s Signed-off-by: James Smart --- drivers/scsi/scsi_lib_dma.c | 13 +++++++++---- include/scsi/scsi_host.h | 21 +++++++++++++++++++++ 2 files changed, 30 insertions(+), 4 deletions(-) diff -upNr a/drivers/scsi/scsi_lib_dma.c b2/drivers/scsi/scsi_lib_dma.c --- a/drivers/scsi/scsi_lib_dma.c 2008-09-23 15:12:13.000000000 -0400 +++ b2/drivers/scsi/scsi_lib_dma.c 2008-10-03 12:19:39.000000000 -0400 @@ -23,9 +23,11 @@ int scsi_dma_map(struct scsi_cmnd *cmd) int nseg =3D 0; =20 if (scsi_sg_count(cmd)) { - struct device *dev =3D cmd->device->host->shost_gendev.parent; + struct Scsi_Host *shost; =20 - nseg =3D dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), + shost =3D dev_to_phys_shost(&cmd->device->sdev_gendev); + nseg =3D dma_map_sg(shost->shost_gendev.parent, + scsi_sglist(cmd), scsi_sg_count(cmd), cmd->sc_data_direction); if (unlikely(!nseg)) return -ENOMEM; @@ -41,10 +43,13 @@ EXPORT_SYMBOL(scsi_dma_map); void scsi_dma_unmap(struct scsi_cmnd *cmd) { if (scsi_sg_count(cmd)) { - struct device *dev =3D cmd->device->host->shost_gendev.parent; + struct Scsi_Host *shost; =20 - dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), + shost =3D dev_to_phys_shost(&cmd->device->sdev_gendev); + dma_unmap_sg(shost->shost_gendev.parent, + scsi_sglist(cmd), scsi_sg_count(cmd), cmd->sc_data_direction); } } EXPORT_SYMBOL(scsi_dma_unmap); + diff -upNr a/include/scsi/scsi_host.h b2/include/scsi/scsi_host.h --- a/include/scsi/scsi_host.h 2008-09-23 15:12:20.000000000 -0400 +++ b2/include/scsi/scsi_host.h 2008-10-03 12:16:46.000000000 -0400 @@ -696,6 +696,10 @@ static inline void *shost_priv(struct Sc =20 int scsi_is_host_device(const struct device *); =20 +/* + * walks object list backward, to find the first shost object. + * Skips over transport objects that may not be stargets, etc + */ static inline struct Scsi_Host *dev_to_shost(struct device *dev) { while (!scsi_is_host_device(dev)) { @@ -706,6 +710,23 @@ static inline struct Scsi_Host *dev_to_s return container_of(dev, struct Scsi_Host, shost_gendev); } =20 +/* + * walks object list backward, to find the top-most shost object. + * Skips over transport objects that may be vports, shosts under vports, etc=20 + */ +static inline struct Scsi_Host *dev_to_phys_shost(struct device *dev) +{ + struct Scsi_Host *shost_new =3D dev_to_shost(dev); + struct Scsi_Host *shost =3D shost_new; + + while (shost_new) { + shost_new =3D dev_to_shost(shost->shost_gendev.parent); + if (shost_new) + shost =3D shost_new; + } + return shost; +} + static inline int scsi_host_in_recovery(struct Scsi_Host *shost) { return shost->shost_state =3D=3D SHOST_RECOVERY || -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html