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authorNicholas Bellinger <nab@daterainc.com>2013-08-21 14:54:54 -0700
committerNicholas Bellinger <nab@linux-iscsi.org>2013-09-10 16:48:35 -0700
commitb3faa2e87ce04e48f16f3823977329b7c367b3f9 (patch)
tree796a8722df5ffa66e29936f5cfdf4624e536208a /include/target
parentcf6d1f0964fa9db57fc660caf51939d7a03359a1 (diff)
downloadlinux-b3faa2e87ce04e48f16f3823977329b7c367b3f9.tar.bz2
target/tcm_qla2xxx: Add/use target_reverse_dma_direction() in target_core_fabric.h
Reversing the dma_data_direction for pci_map_sg() friends is useful for other drivers, so move it from tcm_qla2xxx into inline code within target_core_fabric.h. Also drop internal usage of equivlient in tcm_qla2xxx fabric code. Reported-by: Christoph Hellwig <hch@lst.de> Cc: Roland Dreier <roland@purestorage.com> Cc: Giridhar Malavali <giridhar.malavali@qlogic.com> Cc: Chad Dupuis <chad.dupuis@qlogic.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Nicholas Bellinger <nab@daterainc.com>
Diffstat (limited to 'include/target')
-rw-r--r--include/target/target_core_fabric.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h
index 192eb52684e9..882b650e32be 100644
--- a/include/target/target_core_fabric.h
+++ b/include/target/target_core_fabric.h
@@ -179,4 +179,30 @@ u32 iscsi_get_pr_transport_id_len(struct se_portal_group *, struct se_node_acl *
char *iscsi_parse_pr_out_transport_id(struct se_portal_group *, const char *,
u32 *, char **);
+/*
+ * The LIO target core uses DMA_TO_DEVICE to mean that data is going
+ * to the target (eg handling a WRITE) and DMA_FROM_DEVICE to mean
+ * that data is coming from the target (eg handling a READ). However,
+ * this is just the opposite of what we have to tell the DMA mapping
+ * layer -- eg when handling a READ, the HBA will have to DMA the data
+ * out of memory so it can send it to the initiator, which means we
+ * need to use DMA_TO_DEVICE when we map the data.
+ */
+static inline enum dma_data_direction
+target_reverse_dma_direction(struct se_cmd *se_cmd)
+{
+ if (se_cmd->se_cmd_flags & SCF_BIDI)
+ return DMA_BIDIRECTIONAL;
+
+ switch (se_cmd->data_direction) {
+ case DMA_TO_DEVICE:
+ return DMA_FROM_DEVICE;
+ case DMA_FROM_DEVICE:
+ return DMA_TO_DEVICE;
+ case DMA_NONE:
+ default:
+ return DMA_NONE;
+ }
+}
+
#endif /* TARGET_CORE_FABRICH */