Commit 3320c06b authored by Dariusz Stojaczyk's avatar Dariusz Stojaczyk Committed by Jim Harris
Browse files

nvme/pcie: split HW SGL entries on 2MB address boundary 



This allows NVMe PCIe devices to be used with
physically discontiguous I/O payload buffers.

So far this is just a dumb splitting which
doesn't check for physical contiguity. This is
improved in a subsequent patch.

Change-Id: I0ecc443149225eaa0e4156ddda78613bcf034406
Suggested-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Signed-off-by: default avatarDariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/417060


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarDaniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent bdd0f611

lib/nvme/nvme_pcie.c

+28 −20
Original line number Diff line number Diff line
@@ -1761,6 +1761,8 @@ nvme_pcie_qpair_build_contig_request(struct spdk_nvme_qpair *qpair, struct nvme_ 
	return 0;

}



#define _2MB_OFFSET(ptr)	(((uintptr_t)(ptr)) &  (0x200000 - 1))



/**

 * Build SGL list describing scattered payload buffer.

 */
@@ -1771,7 +1773,7 @@ nvme_pcie_qpair_build_hw_sgl_request(struct spdk_nvme_qpair *qpair, struct nvme_ 
	int rc;

	void *virt_addr;

	uint64_t phys_addr;

	uint32_t remaining_transfer_len, length;

	uint32_t remaining_transfer_len, remaining_user_sge_len, length;

	struct spdk_nvme_sgl_descriptor *sgl;

	uint32_t nseg = 0;
@@ -1791,13 +1793,17 @@ nvme_pcie_qpair_build_hw_sgl_request(struct spdk_nvme_qpair *qpair, struct nvme_ 
	remaining_transfer_len = req->payload_size;



	while (remaining_transfer_len > 0) {

		if (nseg >= NVME_MAX_SGL_DESCRIPTORS) {

		rc = req->payload.next_sge_fn(req->payload.contig_or_cb_arg,

					      &virt_addr, &remaining_user_sge_len);

		if (rc) {

			nvme_pcie_fail_request_bad_vtophys(qpair, tr);

			return -1;

		}



		rc = req->payload.next_sge_fn(req->payload.contig_or_cb_arg, &virt_addr, &length);

		if (rc) {

		remaining_user_sge_len = spdk_min(remaining_user_sge_len, remaining_transfer_len);

		remaining_transfer_len -= remaining_user_sge_len;

		while (remaining_user_sge_len > 0) {

			if (nseg >= NVME_MAX_SGL_DESCRIPTORS) {

				nvme_pcie_fail_request_bad_vtophys(qpair, tr);

				return -1;

			}
@@ -1808,8 +1814,9 @@ nvme_pcie_qpair_build_hw_sgl_request(struct spdk_nvme_qpair *qpair, struct nvme_ 
				return -1;

			}



		length = spdk_min(remaining_transfer_len, length);

		remaining_transfer_len -= length;

			length = spdk_min(remaining_user_sge_len, 0x200000 - _2MB_OFFSET(virt_addr));

			remaining_user_sge_len -= length;

			virt_addr += length;



			sgl->unkeyed.type = SPDK_NVME_SGL_TYPE_DATA_BLOCK;

			sgl->unkeyed.length = length;
@@ -1819,6 +1826,7 @@ nvme_pcie_qpair_build_hw_sgl_request(struct spdk_nvme_qpair *qpair, struct nvme_ 
			sgl++;

			nseg++;

		}

	}



	if (nseg == 1) {

		/*