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authorChristoph Hellwig <hch@lst.de>2015-12-11 22:53:03 +0300
committerChristoph Hellwig <hch@lst.de>2015-12-12 01:10:43 +0300
commit14d3a3b2498edadec344cb11e60e66091f5daf63 (patch)
tree2f6f6b383a94e98f4832061e3bfc66587377a9fa /include/rdma
parent839a301dc2c007ec942b73a0025695056648f59b (diff)
downloadlinux-14d3a3b2498edadec344cb11e60e66091f5daf63.tar.xz
IB: add a proper completion queue abstraction
This adds an abstraction that allows ULPs to simply pass a completion object and completion callback with each submitted WR and let the RDMA core handle the nitty gritty details of how to handle completion interrupts and poll the CQ. In detail there is a new ib_cqe structure which just contains the completion callback, and which can be used to get at the containing object using container_of. It is pointed to by the WR and WC as an alternative to the wr_id field, similar to how many ULPs already use the field to store a pointer using casts. A driver using the new completion callbacks allocates it's CQs using the new ib_create_cq API, which in addition to the number of CQEs and the completion vectors also takes a mode on how we poll for CQEs. Three modes are available: direct for drivers that never take CQ interrupts and just poll for them, softirq to poll from softirq context using the to be renamed blk-iopoll infrastructure which takes care of rearming and budgeting, or a workqueue for consumer who want to be called from user context. Thanks a lot to Sagi Grimberg who helped reviewing the API, wrote the current version of the workqueue code because my two previous attempts sucked too much and converted the iSER initiator to the new API. Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'include/rdma')
-rw-r--r--include/rdma/ib_verbs.h38
1 files changed, 35 insertions, 3 deletions
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 9a68a19532ba..131dd4b5176c 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -49,6 +49,7 @@
#include <linux/scatterlist.h>
#include <linux/workqueue.h>
#include <linux/socket.h>
+#include <linux/irq_poll.h>
#include <uapi/linux/if_ether.h>
#include <linux/atomic.h>
@@ -56,6 +57,7 @@
#include <asm/uaccess.h>
extern struct workqueue_struct *ib_wq;
+extern struct workqueue_struct *ib_comp_wq;
union ib_gid {
u8 raw[16];
@@ -758,7 +760,10 @@ enum ib_wc_flags {
};
struct ib_wc {
- u64 wr_id;
+ union {
+ u64 wr_id;
+ struct ib_cqe *wr_cqe;
+ };
enum ib_wc_status status;
enum ib_wc_opcode opcode;
u32 vendor_err;
@@ -1079,9 +1084,16 @@ struct ib_mw_bind_info {
int mw_access_flags;
};
+struct ib_cqe {
+ void (*done)(struct ib_cq *cq, struct ib_wc *wc);
+};
+
struct ib_send_wr {
struct ib_send_wr *next;
- u64 wr_id;
+ union {
+ u64 wr_id;
+ struct ib_cqe *wr_cqe;
+ };
struct ib_sge *sg_list;
int num_sge;
enum ib_wr_opcode opcode;
@@ -1175,7 +1187,10 @@ static inline struct ib_sig_handover_wr *sig_handover_wr(struct ib_send_wr *wr)
struct ib_recv_wr {
struct ib_recv_wr *next;
- u64 wr_id;
+ union {
+ u64 wr_id;
+ struct ib_cqe *wr_cqe;
+ };
struct ib_sge *sg_list;
int num_sge;
};
@@ -1306,6 +1321,12 @@ struct ib_ah {
typedef void (*ib_comp_handler)(struct ib_cq *cq, void *cq_context);
+enum ib_poll_context {
+ IB_POLL_DIRECT, /* caller context, no hw completions */
+ IB_POLL_SOFTIRQ, /* poll from softirq context */
+ IB_POLL_WORKQUEUE, /* poll from workqueue */
+};
+
struct ib_cq {
struct ib_device *device;
struct ib_uobject *uobject;
@@ -1314,6 +1335,12 @@ struct ib_cq {
void *cq_context;
int cqe;
atomic_t usecnt; /* count number of work queues */
+ enum ib_poll_context poll_ctx;
+ struct ib_wc *wc;
+ union {
+ struct irq_poll iop;
+ struct work_struct work;
+ };
};
struct ib_srq {
@@ -2453,6 +2480,11 @@ static inline int ib_post_recv(struct ib_qp *qp,
return qp->device->post_recv(qp, recv_wr, bad_recv_wr);
}
+struct ib_cq *ib_alloc_cq(struct ib_device *dev, void *private,
+ int nr_cqe, int comp_vector, enum ib_poll_context poll_ctx);
+void ib_free_cq(struct ib_cq *cq);
+int ib_process_cq_direct(struct ib_cq *cq, int budget);
+
/**
* ib_create_cq - Creates a CQ on the specified device.
* @device: The device on which to create the CQ.