IB/srp: Use FMRs to map gather/scatter lists
Create an SRP FMR pool on HCAs that support FMRs, and use FMRs to map
gather/scatter lists that have more than one entry into a single
memory region that appears virtually contiguous to the SRP target
(which is the RDMA initiator).
This patch bails out on FMR mapping for SCSI commands where the
gather/scatter list cannot be mapped into a single FMR because there
are sub-page-sized entries in middle of the list. An unaligned
start or end of the list is OK.
Based on a patch by Vu Pham <vuhuong@mellanox.com>.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index c5cd43a..5ecda4a 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -46,6 +46,7 @@
#include <rdma/ib_verbs.h>
#include <rdma/ib_sa.h>
#include <rdma/ib_cm.h>
+#include <rdma/ib_fmr_pool.h>
enum {
SRP_PATH_REC_TIMEOUT_MS = 1000,
@@ -62,7 +63,11 @@
SRP_SQ_SIZE = SRP_RQ_SIZE - 1,
SRP_CQ_SIZE = SRP_SQ_SIZE + SRP_RQ_SIZE,
- SRP_TAG_TSK_MGMT = 1 << (SRP_RQ_SHIFT + 1)
+ SRP_TAG_TSK_MGMT = 1 << (SRP_RQ_SHIFT + 1),
+
+ SRP_FMR_SIZE = 256,
+ SRP_FMR_POOL_SIZE = 1024,
+ SRP_FMR_DIRTY_SIZE = SRP_FMR_POOL_SIZE / 4
};
#define SRP_OP_RECV (1 << 31)
@@ -77,15 +82,24 @@
SRP_TARGET_REMOVED
};
-struct srp_host {
- u8 initiator_port_id[16];
+struct srp_device {
+ struct list_head dev_list;
struct ib_device *dev;
- u8 port;
struct ib_pd *pd;
struct ib_mr *mr;
+ struct ib_fmr_pool *fmr_pool;
+ int fmr_page_shift;
+ int fmr_page_size;
+ unsigned long fmr_page_mask;
+};
+
+struct srp_host {
+ u8 initiator_port_id[16];
+ struct srp_device *dev;
+ u8 port;
struct class_device class_dev;
struct list_head target_list;
- struct mutex target_mutex;
+ struct mutex target_mutex;
struct completion released;
struct list_head list;
};
@@ -95,6 +109,7 @@
struct scsi_cmnd *scmnd;
struct srp_iu *cmd;
struct srp_iu *tsk_mgmt;
+ struct ib_pool_fmr *fmr;
/*
* Fake scatterlist used when scmnd->use_sg==0. Can be killed
* when the SCSI midlayer no longer generates non-SG commands.