Commit c258d73f authored by Jim Harris's avatar Jim Harris Committed by Darek Stojaczyk
Browse files

ioat: add APIs to only build descriptors 



Add spdk_ioat_build_copy and spdk_ioat_build_fill
which mirror the existing spdk_ioat_submit_copy
and spdk_ioat_submit_fill.  These new functions
*only* build the descriptors in the ring - they do
not write the doorbell.  This enables batching
which can significantly improve performance by
reducing the number of MMIO writes.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: Ia3539f936924b7f833f4a7b963d06ffefa68379f

Reviewed-on: https://review.gerrithub.io/c/444973


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarDarek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
parent ec95646a

include/spdk/ioat.h

+52 −2
Original line number Diff line number Diff line
@@ -108,7 +108,32 @@ int spdk_ioat_probe(void *cb_ctx, spdk_ioat_probe_cb probe_cb, spdk_ioat_attach_ 
void spdk_ioat_detach(struct spdk_ioat_chan *ioat);



/**

 * Submit a DMA engine memory copy request.

 * Build a DMA engine memory copy request.

 *

 * This function will build the descriptor in the channel's ring.  The

 * caller must also explicitly call spdk_ioat_flush to submit the

 * descriptor, possibly after building additional descriptors.

 *

 * \param chan I/OAT channel to build request.

 * \param cb_arg Opaque value which will be passed back as the arg parameter in

 * the completion callback.

 * \param cb_fn Callback function which will be called when the request is complete.

 * \param dst Destination virtual address.

 * \param src Source virtual address.

 * \param nbytes Number of bytes to copy.

 *

 * \return 0 on success, negative errno on failure.

 */

int spdk_ioat_build_copy(struct spdk_ioat_chan *chan,

			 void *cb_arg, spdk_ioat_req_cb cb_fn,

			 void *dst, const void *src, uint64_t nbytes);



/**

 * Build and submit a DMA engine memory copy request.

 *

 * This function will build the descriptor in the channel's ring and then

 * immediately submit it by writing the channel's doorbell.  Calling this

 * function does not require a subsequent call to spdk_ioat_flush.

 *

 * \param chan I/OAT channel to submit request.

 * \param cb_arg Opaque value which will be passed back as the arg parameter in
@@ -125,7 +150,32 @@ int spdk_ioat_submit_copy(struct spdk_ioat_chan *chan, 
			  void *dst, const void *src, uint64_t nbytes);



/**

 * Submit a DMA engine memory fill request.

 * Build a DMA engine memory fill request.

 *

 * This function will build the descriptor in the channel's ring.  The

 * caller must also explicitly call spdk_ioat_flush to submit the

 * descriptor, possibly after building additional descriptors.

 *

 * \param chan I/OAT channel to build request.

 * \param cb_arg Opaque value which will be passed back as the cb_arg parameter

 * in the completion callback.

 * \param cb_fn Callback function which will be called when the request is complete.

 * \param dst Destination virtual address.

 * \param fill_pattern Repeating eight-byte pattern to use for memory fill.

 * \param nbytes Number of bytes to fill.

 *

 * \return 0 on success, negative errno on failure.

 */

int spdk_ioat_build_fill(struct spdk_ioat_chan *chan,

			 void *cb_arg, spdk_ioat_req_cb cb_fn,

			 void *dst, uint64_t fill_pattern, uint64_t nbytes);



/**

 * Build and submit a DMA engine memory fill request.

 *

 * This function will build the descriptor in the channel's ring and then

 * immediately submit it by writing the channel's doorbell.  Calling this

 * function does not require a subsequent call to spdk_ioat_flush.

 *

 * \param chan I/OAT channel to submit request.

 * \param cb_arg Opaque value which will be passed back as the cb_arg parameter

lib/ioat/ioat.c

+32 −4
Original line number Diff line number Diff line
@@ -584,7 +584,7 @@ spdk_ioat_detach(struct spdk_ioat_chan *ioat) 
}



int

spdk_ioat_submit_copy(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_cb cb_fn,

spdk_ioat_build_copy(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_cb cb_fn,

		     void *dst, const void *src, uint64_t nbytes)

{

	struct ioat_descriptor	*last_desc;
@@ -652,12 +652,26 @@ spdk_ioat_submit_copy(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_c 
		return -ENOMEM;

	}



	return 0;

}



int

spdk_ioat_submit_copy(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_cb cb_fn,

		      void *dst, const void *src, uint64_t nbytes)

{

	int rc;



	rc = spdk_ioat_build_copy(ioat, cb_arg, cb_fn, dst, src, nbytes);

	if (rc != 0) {

		return rc;

	}



	spdk_ioat_flush(ioat);

	return 0;

}



int

spdk_ioat_submit_fill(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_cb cb_fn,

spdk_ioat_build_fill(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_cb cb_fn,

		     void *dst, uint64_t fill_pattern, uint64_t nbytes)

{

	struct ioat_descriptor	*last_desc = NULL;
@@ -709,6 +723,20 @@ spdk_ioat_submit_fill(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_c 
		return -ENOMEM;

	}



	return 0;

}



int

spdk_ioat_submit_fill(struct spdk_ioat_chan *ioat, void *cb_arg, spdk_ioat_req_cb cb_fn,

		      void *dst, uint64_t fill_pattern, uint64_t nbytes)

{

	int rc;



	rc = spdk_ioat_build_fill(ioat, cb_arg, cb_fn, dst, fill_pattern, nbytes);

	if (rc != 0) {

		return rc;

	}



	spdk_ioat_flush(ioat);

	return 0;

}