On Tue, 2009-11-03 at 19:45 -0500, James Smart wrote: > I had reminded James B of a patch for an issue with the scsi subsystem > not properly finding the parent device for dma operations when we had > nested scsi_hosts.. > http://marc.info/?l=linux-scsi&m=125372757108048&w=2 > > The patch was picked up, and integrated into linux-next, which started > to see issues, and which James B cut an additional patch to deal with > traversing too much of the tree (stopping when dev->parent == NULL).. > The http://marc.info/?l=linux-scsi&m=125414973520985&w=2 > > The real issue was the traversal of a node that had "dev->type == NULL". > Turns out standard PCI endpoint and bridge/domain objects have NULL types > too - so every traversal went all the way to the root of the tree. > > The attached patch, cut against scsi-misc-2.6 - replaces both of the > patches above. Rather than making any assumptions about dev->type values, > it now explicitly matches dev->type structures to known scsi or transport > objects, and only traverses them if they are recognized. To get around > symbol dependencies, and to allow transports as modules to come and go, > a registration interface was put in place to register transport objects > with the routine that does the matching. The FC transport was converted > to use a device_type structure for its objects (note: perhaps other > transports should consider the same ?) > > Please apply this patch as soon as possible. At the current time, > NPIV vport dma operation is severely broken. > > Thanks > > -- james s > > > > > Signed-off-by: James Smart <james.smart@xxxxxxxxxx> > > --- > > drivers/scsi/hosts.c | 72 +++++++++++++++++++++++++++++++++++++++ > drivers/scsi/scsi_lib.c | 2 - > drivers/scsi/scsi_lib_dma.c | 7 ++- > drivers/scsi/scsi_priv.h | 2 + > drivers/scsi/scsi_transport_fc.c | 48 +++++++++++++++++++++++--- > include/scsi/scsi_host.h | 17 +++++++++ > 6 files changed, 141 insertions(+), 7 deletions(-) 141 lines plus a static list to solve a simple problem is getting a bit icky to say the least. What about being more simplistic and simply making the host cache a pointer to the physical bus device? I probably objected to this a long time ago because using the parent pointers is more elegant, but I think this patch demonstrates conclusively it's not worth this amount of code for the sake of alleged elegance. James --- drivers/scsi/hosts.c | 13 ++++++++++--- drivers/scsi/lpfc/lpfc_init.c | 2 +- drivers/scsi/qla2xxx/qla_attr.c | 3 ++- drivers/scsi/scsi_lib_dma.c | 4 ++-- include/scsi/scsi_host.h | 16 +++++++++++++++- 5 files changed, 30 insertions(+), 8 deletions(-) --- diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 5fd2da4..28a753d 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -180,14 +180,20 @@ void scsi_remove_host(struct Scsi_Host *shost) EXPORT_SYMBOL(scsi_remove_host); /** - * scsi_add_host - add a scsi host + * scsi_add_host_with_dma - add a scsi host with dma device * @shost: scsi host pointer to add * @dev: a struct device of type scsi class + * @dma_dev: dma device for the host + * + * Note: You rarely need to worry about this unless you're in a + * virtualised host environments, so use the simpler scsi_add_host() + * function instead. * * Return value: * 0 on success / != 0 for error **/ -int scsi_add_host(struct Scsi_Host *shost, struct device *dev) +int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, + struct device *dma_dev) { struct scsi_host_template *sht = shost->hostt; int error = -EINVAL; @@ -207,6 +213,7 @@ int scsi_add_host(struct Scsi_Host *shost, struct device *dev) if (!shost->shost_gendev.parent) shost->shost_gendev.parent = dev ? dev : &platform_bus; + shost->dma_dev = dma_dev; error = device_add(&shost->shost_gendev); if (error) @@ -262,7 +269,7 @@ int scsi_add_host(struct Scsi_Host *shost, struct device *dev) fail: return error; } -EXPORT_SYMBOL(scsi_add_host); +EXPORT_SYMBOL(scsi_add_host_with_dma); static void scsi_host_dev_release(struct device *dev) { diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c index 562d8ce..f913f1e 100644 --- a/drivers/scsi/lpfc/lpfc_init.c +++ b/drivers/scsi/lpfc/lpfc_init.c @@ -2408,7 +2408,7 @@ lpfc_create_port(struct lpfc_hba *phba, int instance, struct device *dev) vport->els_tmofunc.function = lpfc_els_timeout; vport->els_tmofunc.data = (unsigned long)vport; - error = scsi_add_host(shost, dev); + error = scsi_add_host_with_dma(shost, dev, &phba->pcidev->dev); if (error) goto out_put_shost; diff --git a/drivers/scsi/qla2xxx/qla_attr.c b/drivers/scsi/qla2xxx/qla_attr.c index fbcb82a..21e2bc4 100644 --- a/drivers/scsi/qla2xxx/qla_attr.c +++ b/drivers/scsi/qla2xxx/qla_attr.c @@ -1654,7 +1654,8 @@ qla24xx_vport_create(struct fc_vport *fc_vport, bool disable) fc_vport_set_state(fc_vport, FC_VPORT_LINKDOWN); } - if (scsi_add_host(vha->host, &fc_vport->dev)) { + if (scsi_add_host_with_dma(vha->host, &fc_vport->dev, + &ha->pdev->dev)) { DEBUG15(printk("scsi(%ld): scsi_add_host failure for VP[%d].\n", vha->host_no, vha->vp_idx)); goto vport_create_failed_2; diff --git a/drivers/scsi/scsi_lib_dma.c b/drivers/scsi/scsi_lib_dma.c index ac6855c..dcd1285 100644 --- a/drivers/scsi/scsi_lib_dma.c +++ b/drivers/scsi/scsi_lib_dma.c @@ -23,7 +23,7 @@ int scsi_dma_map(struct scsi_cmnd *cmd) int nseg = 0; if (scsi_sg_count(cmd)) { - struct device *dev = cmd->device->host->shost_gendev.parent; + struct device *dev = cmd->device->host->dma_dev; nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), cmd->sc_data_direction); @@ -41,7 +41,7 @@ EXPORT_SYMBOL(scsi_dma_map); void scsi_dma_unmap(struct scsi_cmnd *cmd) { if (scsi_sg_count(cmd)) { - struct device *dev = cmd->device->host->shost_gendev.parent; + struct device *dev = cmd->device->host->dma_dev; dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd), cmd->sc_data_direction); diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 943f5df..68338be 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -683,6 +683,12 @@ struct Scsi_Host { void *shost_data; /* + * Points to the physical bus device we'd use to do DMA + * Needed just in case we have virtual hosts. + */ + struct device *dma_dev; + + /* * We should ensure that this is aligned, both for better performance * and also because some compilers (m68k) don't automatically force * alignment to a long boundary. @@ -726,7 +732,9 @@ extern int scsi_queue_work(struct Scsi_Host *, struct work_struct *); extern void scsi_flush_work(struct Scsi_Host *); extern struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *, int); -extern int __must_check scsi_add_host(struct Scsi_Host *, struct device *); +extern int __must_check scsi_add_host_with_dma(struct Scsi_Host *, + struct device *, + struct device *); extern void scsi_scan_host(struct Scsi_Host *); extern void scsi_rescan_device(struct device *); extern void scsi_remove_host(struct Scsi_Host *); @@ -737,6 +745,12 @@ extern const char *scsi_host_state_name(enum scsi_host_state); extern u64 scsi_calculate_bounce_limit(struct Scsi_Host *); +static inline int __must_check scsi_add_host(struct Scsi_Host *host, + struct device *dev) +{ + return scsi_add_host_with_dma(host, dev, dev); +} + static inline struct device *scsi_get_device(struct Scsi_Host *shost) { return shost->shost_gendev.parent; -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
