Commit 4af4e4f5 authored by Daniel Verkamp's avatar Daniel Verkamp Committed by Jim Harris
Browse files

nvme: adjust physically contiguous memory comments 



The NVMe PCIe transport only requires physically contiguous allocations
for struct nvme_tracker and the I/O SQ and CQ entries, which are already
handled separately.  Change the comments to indicate that struct
nvme_payload's contiguous type only requires the memory to be virtually
contiguous, since nvme_pcie_prp_list_append() already steps through the
buffer and translates each (4K) page independently.

Change-Id: I45ac8dfb2c033a0fcbf2effbe33af4efc1eb23cb
Reported-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Signed-off-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/417045


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarPawel Wodkowski <pawelx.wodkowski@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 95fe9280

lib/nvme/nvme.c

+7 −7
Original line number Diff line number Diff line
@@ -166,7 +166,7 @@ nvme_user_copy_cmd_complete(void *arg, const struct spdk_nvme_cpl *cpl) 
}



/**

 * Allocate a request as well as a physically contiguous buffer to copy to/from the user's buffer.

 * Allocate a request as well as a DMA-capable buffer to copy to/from the user's buffer.

 *

 * This is intended for use in non-fast-path functions (admin commands, reservations, etc.)

 * where the overhead of a copy is not a problem.
@@ -177,24 +177,24 @@ nvme_allocate_request_user_copy(struct spdk_nvme_qpair *qpair, 
				void *cb_arg, bool host_to_controller)

{

	struct nvme_request *req;

	void *contig_buffer = NULL;

	void *dma_buffer = NULL;

	uint64_t phys_addr;



	if (buffer && payload_size) {

		contig_buffer = spdk_dma_zmalloc(payload_size, 4096, &phys_addr);

		if (!contig_buffer) {

		dma_buffer = spdk_dma_zmalloc(payload_size, 4096, &phys_addr);

		if (!dma_buffer) {

			return NULL;

		}



		if (host_to_controller) {

			memcpy(contig_buffer, buffer, payload_size);

			memcpy(dma_buffer, buffer, payload_size);

		}

	}



	req = nvme_allocate_request_contig(qpair, contig_buffer, payload_size, nvme_user_copy_cmd_complete,

	req = nvme_allocate_request_contig(qpair, dma_buffer, payload_size, nvme_user_copy_cmd_complete,

					   NULL);

	if (!req) {

		spdk_dma_free(contig_buffer);

		spdk_dma_free(dma_buffer);

		return NULL;

	}

lib/nvme/nvme_internal.h

+2 −2
Original line number Diff line number Diff line
@@ -155,14 +155,14 @@ struct nvme_payload { 


	/**

	 * If reset_sgl_fn == NULL, this is a contig payload, and contig_or_cb_arg contains the

	 * virtual memory address of a single physically contiguous buffer.

	 * virtual memory address of a single virtually contiguous buffer.

	 *

	 * If reset_sgl_fn != NULL, this is a SGL payload, and contig_or_cb_arg contains the

	 * cb_arg that will be passed to the SGL callback functions.

	 */

	void *contig_or_cb_arg;



	/** Virtual memory address of a single physically contiguous metadata buffer */

	/** Virtual memory address of a single virtually contiguous metadata buffer */

	void *md;

};