When the updated scsi dma code was introduced recently, it assumed 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=dev->parent;
If there is a better solution, please let me know.
-- james s
Signed-off-by: James Smart <james.smart@xxxxxxxxxx>
---
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 = 0;
if (scsi_sg_count(cmd)) {
- struct device *dev = cmd->device->host->shost_gendev.parent;
+ struct Scsi_Host *shost;
- nseg = dma_map_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
+ shost = dev_to_phys_shost(&cmd->device->sdev_gendev);
+ nseg = 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 = cmd->device->host->shost_gendev.parent;
+ struct Scsi_Host *shost;
- dma_unmap_sg(dev, scsi_sglist(cmd), scsi_sg_count(cmd),
+ shost = 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
int scsi_is_host_device(const struct device *);
+/*
+ * 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);
}
+/*
+ * walks object list backward, to find the top-most shost object.
+ * Skips over transport objects that may be vports, shosts under
vports, etc
+ */
+static inline struct Scsi_Host *dev_to_phys_shost(struct device *dev)
+{
+ struct Scsi_Host *shost_new = dev_to_shost(dev);
+ struct Scsi_Host *shost = shost_new;
+
+ while (shost_new) {
+ shost_new = dev_to_shost(shost->shost_gendev.parent);
+ if (shost_new)
+ shost = shost_new;
+ }
+ return shost;
+}
+
static inline int scsi_host_in_recovery(struct Scsi_Host *shost)
{
return shost->shost_state == SHOST_RECOVERY ||
--
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