Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 742 insertions, 0 deletions

diff --git a/drivers/crypto/cavium/nitrox/nitrox_reqmgr.c b/drivers/crypto/cavium/nitrox/nitrox_reqmgr.c
new file mode 100644
index 000000000..4a362fc22
--- /dev/null
+++ b/drivers/crypto/cavium/nitrox/nitrox_reqmgr.c
@@ -0,0 +1,742 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/gfp.h>
+#include <linux/workqueue.h>
+#include <crypto/internal/skcipher.h>
+
+#include "nitrox_dev.h"
+#include "nitrox_req.h"
+#include "nitrox_csr.h"
+
+/* SLC_STORE_INFO */
+#define MIN_UDD_LEN 16
+/* PKT_IN_HDR + SLC_STORE_INFO */
+#define FDATA_SIZE 32
+/* Base destination port for the solicited requests */
+#define SOLICIT_BASE_DPORT 256
+#define PENDING_SIG	0xFFFFFFFFFFFFFFFFUL
+
+#define REQ_NOT_POSTED 1
+#define REQ_BACKLOG    2
+#define REQ_POSTED     3
+
+/**
+ * Response codes from SE microcode
+ * 0x00 - Success
+ *   Completion with no error
+ * 0x43 - ERR_GC_DATA_LEN_INVALID
+ *   Invalid Data length if Encryption Data length is
+ *   less than 16 bytes for AES-XTS and AES-CTS.
+ * 0x45 - ERR_GC_CTX_LEN_INVALID
+ *   Invalid context length: CTXL != 23 words.
+ * 0x4F - ERR_GC_DOCSIS_CIPHER_INVALID
+ *   DOCSIS support is enabled with other than
+ *   AES/DES-CBC mode encryption.
+ * 0x50 - ERR_GC_DOCSIS_OFFSET_INVALID
+ *   Authentication offset is other than 0 with
+ *   Encryption IV source = 0.
+ *   Authentication offset is other than 8 (DES)/16 (AES)
+ *   with Encryption IV source = 1
+ * 0x51 - ERR_GC_CRC32_INVALID_SELECTION
+ *   CRC32 is enabled for other than DOCSIS encryption.
+ * 0x52 - ERR_GC_AES_CCM_FLAG_INVALID
+ *   Invalid flag options in AES-CCM IV.
+ */
+
+static inline int incr_index(int index, int count, int max)
+{
+	if ((index + count) >= max)
+		index = index + count - max;
+	else
+		index += count;
+
+	return index;
+}
+
+/**
+ * dma_free_sglist - unmap and free the sg lists.
+ * @ndev: N5 device
+ * @sgtbl: SG table
+ */
+static void softreq_unmap_sgbufs(struct nitrox_softreq *sr)
+{
+	struct nitrox_device *ndev = sr->ndev;
+	struct device *dev = DEV(ndev);
+	struct nitrox_sglist *sglist;
+
+	/* unmap in sgbuf */
+	sglist = sr->in.sglist;
+	if (!sglist)
+		goto out_unmap;
+
+	/* unmap iv */
+	dma_unmap_single(dev, sglist->dma, sglist->len, DMA_BIDIRECTIONAL);
+	/* unmpa src sglist */
+	dma_unmap_sg(dev, sr->in.buf, (sr->in.map_bufs_cnt - 1), sr->in.dir);
+	/* unamp gather component */
+	dma_unmap_single(dev, sr->in.dma, sr->in.len, DMA_TO_DEVICE);
+	kfree(sr->in.sglist);
+	kfree(sr->in.sgcomp);
+	sr->in.sglist = NULL;
+	sr->in.buf = NULL;
+	sr->in.map_bufs_cnt = 0;
+
+out_unmap:
+	/* unmap out sgbuf */
+	sglist = sr->out.sglist;
+	if (!sglist)
+		return;
+
+	/* unmap orh */
+	dma_unmap_single(dev, sr->resp.orh_dma, ORH_HLEN, sr->out.dir);
+
+	/* unmap dst sglist */
+	if (!sr->inplace) {
+		dma_unmap_sg(dev, sr->out.buf, (sr->out.map_bufs_cnt - 3),
+			     sr->out.dir);
+	}
+	/* unmap completion */
+	dma_unmap_single(dev, sr->resp.completion_dma, COMP_HLEN, sr->out.dir);
+
+	/* unmap scatter component */
+	dma_unmap_single(dev, sr->out.dma, sr->out.len, DMA_TO_DEVICE);
+	kfree(sr->out.sglist);
+	kfree(sr->out.sgcomp);
+	sr->out.sglist = NULL;
+	sr->out.buf = NULL;
+	sr->out.map_bufs_cnt = 0;
+}
+
+static void softreq_destroy(struct nitrox_softreq *sr)
+{
+	softreq_unmap_sgbufs(sr);
+	kfree(sr);
+}
+
+/**
+ * create_sg_component - create SG componets for N5 device.
+ * @sr: Request structure
+ * @sgtbl: SG table
+ * @nr_comp: total number of components required
+ *
+ * Component structure
+ *
+ *   63     48 47     32 31    16 15      0
+ *   --------------------------------------
+ *   |   LEN0  |  LEN1  |  LEN2  |  LEN3  |
+ *   |-------------------------------------
+ *   |               PTR0                 |
+ *   --------------------------------------
+ *   |               PTR1                 |
+ *   --------------------------------------
+ *   |               PTR2                 |
+ *   --------------------------------------
+ *   |               PTR3                 |
+ *   --------------------------------------
+ *
+ *   Returns 0 if success or a negative errno code on error.
+ */
+static int create_sg_component(struct nitrox_softreq *sr,
+			       struct nitrox_sgtable *sgtbl, int map_nents)
+{
+	struct nitrox_device *ndev = sr->ndev;
+	struct nitrox_sgcomp *sgcomp;
+	struct nitrox_sglist *sglist;
+	dma_addr_t dma;
+	size_t sz_comp;
+	int i, j, nr_sgcomp;
+
+	nr_sgcomp = roundup(map_nents, 4) / 4;
+
+	/* each component holds 4 dma pointers */
+	sz_comp = nr_sgcomp * sizeof(*sgcomp);
+	sgcomp = kzalloc(sz_comp, sr->gfp);
+	if (!sgcomp)
+		return -ENOMEM;
+
+	sgtbl->sgcomp = sgcomp;
+	sgtbl->nr_sgcomp = nr_sgcomp;
+
+	sglist = sgtbl->sglist;
+	/* populate device sg component */
+	for (i = 0; i < nr_sgcomp; i++) {
+		for (j = 0; j < 4; j++) {
+			sgcomp->len[j] = cpu_to_be16(sglist->len);
+			sgcomp->dma[j] = cpu_to_be64(sglist->dma);
+			sglist++;
+		}
+		sgcomp++;
+	}
+	/* map the device sg component */
+	dma = dma_map_single(DEV(ndev), sgtbl->sgcomp, sz_comp, DMA_TO_DEVICE);
+	if (dma_mapping_error(DEV(ndev), dma)) {
+		kfree(sgtbl->sgcomp);
+		sgtbl->sgcomp = NULL;
+		return -ENOMEM;
+	}
+
+	sgtbl->dma = dma;
+	sgtbl->len = sz_comp;
+
+	return 0;
+}
+
+/**
+ * dma_map_inbufs - DMA map input sglist and creates sglist component
+ *                  for N5 device.
+ * @sr: Request structure
+ * @req: Crypto request structre
+ *
+ * Returns 0 if successful or a negative errno code on error.
+ */
+static int dma_map_inbufs(struct nitrox_softreq *sr,
+			  struct se_crypto_request *req)
+{
+	struct device *dev = DEV(sr->ndev);
+	struct scatterlist *sg = req->src;
+	struct nitrox_sglist *glist;
+	int i, nents, ret = 0;
+	dma_addr_t dma;
+	size_t sz;
+
+	nents = sg_nents(req->src);
+
+	/* creater gather list IV and src entries */
+	sz = roundup((1 + nents), 4) * sizeof(*glist);
+	glist = kzalloc(sz, sr->gfp);
+	if (!glist)
+		return -ENOMEM;
+
+	sr->in.sglist = glist;
+	/* map IV */
+	dma = dma_map_single(dev, &req->iv, req->ivsize, DMA_BIDIRECTIONAL);
+	if (dma_mapping_error(dev, dma)) {
+		ret = -EINVAL;
+		goto iv_map_err;
+	}
+
+	sr->in.dir = (req->src == req->dst) ? DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
+	/* map src entries */
+	nents = dma_map_sg(dev, req->src, nents, sr->in.dir);
+	if (!nents) {
+		ret = -EINVAL;
+		goto src_map_err;
+	}
+	sr->in.buf = req->src;
+
+	/* store the mappings */
+	glist->len = req->ivsize;
+	glist->dma = dma;
+	glist++;
+	sr->in.total_bytes += req->ivsize;
+
+	for_each_sg(req->src, sg, nents, i) {
+		glist->len = sg_dma_len(sg);
+		glist->dma = sg_dma_address(sg);
+		sr->in.total_bytes += glist->len;
+		glist++;
+	}
+	/* roundup map count to align with entires in sg component */
+	sr->in.map_bufs_cnt = (1 + nents);
+
+	/* create NITROX gather component */
+	ret = create_sg_component(sr, &sr->in, sr->in.map_bufs_cnt);
+	if (ret)
+		goto incomp_err;
+
+	return 0;
+
+incomp_err:
+	dma_unmap_sg(dev, req->src, nents, sr->in.dir);
+	sr->in.map_bufs_cnt = 0;
+src_map_err:
+	dma_unmap_single(dev, dma, req->ivsize, DMA_BIDIRECTIONAL);
+iv_map_err:
+	kfree(sr->in.sglist);
+	sr->in.sglist = NULL;
+	return ret;
+}
+
+static int dma_map_outbufs(struct nitrox_softreq *sr,
+			   struct se_crypto_request *req)
+{
+	struct device *dev = DEV(sr->ndev);
+	struct nitrox_sglist *glist = sr->in.sglist;
+	struct nitrox_sglist *slist;
+	struct scatterlist *sg;
+	int i, nents, map_bufs_cnt, ret = 0;
+	size_t sz;
+
+	nents = sg_nents(req->dst);
+
+	/* create scatter list ORH, IV, dst entries and Completion header */
+	sz = roundup((3 + nents), 4) * sizeof(*slist);
+	slist = kzalloc(sz, sr->gfp);
+	if (!slist)
+		return -ENOMEM;
+
+	sr->out.sglist = slist;
+	sr->out.dir = DMA_BIDIRECTIONAL;
+	/* map ORH */
+	sr->resp.orh_dma = dma_map_single(dev, &sr->resp.orh, ORH_HLEN,
+					  sr->out.dir);
+	if (dma_mapping_error(dev, sr->resp.orh_dma)) {
+		ret = -EINVAL;
+		goto orh_map_err;
+	}
+
+	/* map completion */
+	sr->resp.completion_dma = dma_map_single(dev, &sr->resp.completion,
+						 COMP_HLEN, sr->out.dir);
+	if (dma_mapping_error(dev, sr->resp.completion_dma)) {
+		ret = -EINVAL;
+		goto compl_map_err;
+	}
+
+	sr->inplace = (req->src == req->dst) ? true : false;
+	/* out place */
+	if (!sr->inplace) {
+		nents = dma_map_sg(dev, req->dst, nents, sr->out.dir);
+		if (!nents) {
+			ret = -EINVAL;
+			goto dst_map_err;
+		}
+	}
+	sr->out.buf = req->dst;
+
+	/* store the mappings */
+	/* orh */
+	slist->len = ORH_HLEN;
+	slist->dma = sr->resp.orh_dma;
+	slist++;
+
+	/* copy the glist mappings */
+	if (sr->inplace) {
+		nents = sr->in.map_bufs_cnt - 1;
+		map_bufs_cnt = sr->in.map_bufs_cnt;
+		while (map_bufs_cnt--) {
+			slist->len = glist->len;
+			slist->dma = glist->dma;
+			slist++;
+			glist++;
+		}
+	} else {
+		/* copy iv mapping */
+		slist->len = glist->len;
+		slist->dma = glist->dma;
+		slist++;
+		/* copy remaining maps */
+		for_each_sg(req->dst, sg, nents, i) {
+			slist->len = sg_dma_len(sg);
+			slist->dma = sg_dma_address(sg);
+			slist++;
+		}
+	}
+
+	/* completion */
+	slist->len = COMP_HLEN;
+	slist->dma = sr->resp.completion_dma;
+
+	sr->out.map_bufs_cnt = (3 + nents);
+
+	ret = create_sg_component(sr, &sr->out, sr->out.map_bufs_cnt);
+	if (ret)
+		goto outcomp_map_err;
+
+	return 0;
+
+outcomp_map_err:
+	if (!sr->inplace)
+		dma_unmap_sg(dev, req->dst, nents, sr->out.dir);
+	sr->out.map_bufs_cnt = 0;
+	sr->out.buf = NULL;
+dst_map_err:
+	dma_unmap_single(dev, sr->resp.completion_dma, COMP_HLEN, sr->out.dir);
+	sr->resp.completion_dma = 0;
+compl_map_err:
+	dma_unmap_single(dev, sr->resp.orh_dma, ORH_HLEN, sr->out.dir);
+	sr->resp.orh_dma = 0;
+orh_map_err:
+	kfree(sr->out.sglist);
+	sr->out.sglist = NULL;
+	return ret;
+}
+
+static inline int softreq_map_iobuf(struct nitrox_softreq *sr,
+				    struct se_crypto_request *creq)
+{
+	int ret;
+
+	ret = dma_map_inbufs(sr, creq);
+	if (ret)
+		return ret;
+
+	ret = dma_map_outbufs(sr, creq);
+	if (ret)
+		softreq_unmap_sgbufs(sr);
+
+	return ret;
+}
+
+static inline void backlog_list_add(struct nitrox_softreq *sr,
+				    struct nitrox_cmdq *cmdq)
+{
+	INIT_LIST_HEAD(&sr->backlog);
+
+	spin_lock_bh(&cmdq->backlog_lock);
+	list_add_tail(&sr->backlog, &cmdq->backlog_head);
+	atomic_inc(&cmdq->backlog_count);
+	atomic_set(&sr->status, REQ_BACKLOG);
+	spin_unlock_bh(&cmdq->backlog_lock);
+}
+
+static inline void response_list_add(struct nitrox_softreq *sr,
+				     struct nitrox_cmdq *cmdq)
+{
+	INIT_LIST_HEAD(&sr->response);
+
+	spin_lock_bh(&cmdq->response_lock);
+	list_add_tail(&sr->response, &cmdq->response_head);
+	spin_unlock_bh(&cmdq->response_lock);
+}
+
+static inline void response_list_del(struct nitrox_softreq *sr,
+				     struct nitrox_cmdq *cmdq)
+{
+	spin_lock_bh(&cmdq->response_lock);
+	list_del(&sr->response);
+	spin_unlock_bh(&cmdq->response_lock);
+}
+
+static struct nitrox_softreq *
+get_first_response_entry(struct nitrox_cmdq *cmdq)
+{
+	return list_first_entry_or_null(&cmdq->response_head,
+					struct nitrox_softreq, response);
+}
+
+static inline bool cmdq_full(struct nitrox_cmdq *cmdq, int qlen)
+{
+	if (atomic_inc_return(&cmdq->pending_count) > qlen) {
+		atomic_dec(&cmdq->pending_count);
+		/* sync with other cpus */
+		smp_mb__after_atomic();
+		return true;
+	}
+	return false;
+}
+
+/**
+ * post_se_instr - Post SE instruction to Packet Input ring
+ * @sr: Request structure
+ *
+ * Returns 0 if successful or a negative error code,
+ * if no space in ring.
+ */
+static void post_se_instr(struct nitrox_softreq *sr,
+			  struct nitrox_cmdq *cmdq)
+{
+	struct nitrox_device *ndev = sr->ndev;
+	int idx;
+	u8 *ent;
+
+	spin_lock_bh(&cmdq->cmdq_lock);
+
+	idx = cmdq->write_idx;
+	/* copy the instruction */
+	ent = cmdq->head + (idx * cmdq->instr_size);
+	memcpy(ent, &sr->instr, cmdq->instr_size);
+
+	atomic_set(&sr->status, REQ_POSTED);
+	response_list_add(sr, cmdq);
+	sr->tstamp = jiffies;
+	/* flush the command queue updates */
+	dma_wmb();
+
+	/* Ring doorbell with count 1 */
+	writeq(1, cmdq->dbell_csr_addr);
+	/* orders the doorbell rings */
+	mmiowb();
+
+	cmdq->write_idx = incr_index(idx, 1, ndev->qlen);
+
+	spin_unlock_bh(&cmdq->cmdq_lock);
+}
+
+static int post_backlog_cmds(struct nitrox_cmdq *cmdq)
+{
+	struct nitrox_device *ndev = cmdq->ndev;
+	struct nitrox_softreq *sr, *tmp;
+	int ret = 0;
+
+	if (!atomic_read(&cmdq->backlog_count))
+		return 0;
+
+	spin_lock_bh(&cmdq->backlog_lock);
+
+	list_for_each_entry_safe(sr, tmp, &cmdq->backlog_head, backlog) {
+		struct skcipher_request *skreq;
+
+		/* submit until space available */
+		if (unlikely(cmdq_full(cmdq, ndev->qlen))) {
+			ret = -ENOSPC;
+			break;
+		}
+		/* delete from backlog list */
+		list_del(&sr->backlog);
+		atomic_dec(&cmdq->backlog_count);
+		/* sync with other cpus */
+		smp_mb__after_atomic();
+
+		skreq = sr->skreq;
+		/* post the command */
+		post_se_instr(sr, cmdq);
+
+		/* backlog requests are posted, wakeup with -EINPROGRESS */
+		skcipher_request_complete(skreq, -EINPROGRESS);
+	}
+	spin_unlock_bh(&cmdq->backlog_lock);
+
+	return ret;
+}
+
+static int nitrox_enqueue_request(struct nitrox_softreq *sr)
+{
+	struct nitrox_cmdq *cmdq = sr->cmdq;
+	struct nitrox_device *ndev = sr->ndev;
+
+	/* try to post backlog requests */
+	post_backlog_cmds(cmdq);
+
+	if (unlikely(cmdq_full(cmdq, ndev->qlen))) {
+		if (!(sr->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
+			return -ENOSPC;
+		/* add to backlog list */
+		backlog_list_add(sr, cmdq);
+		return -EBUSY;
+	}
+	post_se_instr(sr, cmdq);
+
+	return -EINPROGRESS;
+}
+
+/**
+ * nitrox_se_request - Send request to SE core
+ * @ndev: NITROX device
+ * @req: Crypto request
+ *
+ * Returns 0 on success, or a negative error code.
+ */
+int nitrox_process_se_request(struct nitrox_device *ndev,
+			      struct se_crypto_request *req,
+			      completion_t callback,
+			      struct skcipher_request *skreq)
+{
+	struct nitrox_softreq *sr;
+	dma_addr_t ctx_handle = 0;
+	int qno, ret = 0;
+
+	if (!nitrox_ready(ndev))
+		return -ENODEV;
+
+	sr = kzalloc(sizeof(*sr), req->gfp);
+	if (!sr)
+		return -ENOMEM;
+
+	sr->ndev = ndev;
+	sr->flags = req->flags;
+	sr->gfp = req->gfp;
+	sr->callback = callback;
+	sr->skreq = skreq;
+
+	atomic_set(&sr->status, REQ_NOT_POSTED);
+
+	WRITE_ONCE(sr->resp.orh, PENDING_SIG);
+	WRITE_ONCE(sr->resp.completion, PENDING_SIG);
+
+	ret = softreq_map_iobuf(sr, req);
+	if (ret) {
+		kfree(sr);
+		return ret;
+	}
+
+	/* get the context handle */
+	if (req->ctx_handle) {
+		struct ctx_hdr *hdr;
+		u8 *ctx_ptr;
+
+		ctx_ptr = (u8 *)(uintptr_t)req->ctx_handle;
+		hdr = (struct ctx_hdr *)(ctx_ptr - sizeof(struct ctx_hdr));
+		ctx_handle = hdr->ctx_dma;
+	}
+
+	/* select the queue */
+	qno = smp_processor_id() % ndev->nr_queues;
+
+	sr->cmdq = &ndev->pkt_cmdqs[qno];
+
+	/*
+	 * 64-Byte Instruction Format
+	 *
+	 *  ----------------------
+	 *  |      DPTR0         | 8 bytes
+	 *  ----------------------
+	 *  |  PKT_IN_INSTR_HDR  | 8 bytes
+	 *  ----------------------
+	 *  |    PKT_IN_HDR      | 16 bytes
+	 *  ----------------------
+	 *  |    SLC_INFO        | 16 bytes
+	 *  ----------------------
+	 *  |   Front data       | 16 bytes
+	 *  ----------------------
+	 */
+
+	/* fill the packet instruction */
+	/* word 0 */
+	sr->instr.dptr0 = cpu_to_be64(sr->in.dma);
+
+	/* word 1 */
+	sr->instr.ih.value = 0;
+	sr->instr.ih.s.g = 1;
+	sr->instr.ih.s.gsz = sr->in.map_bufs_cnt;
+	sr->instr.ih.s.ssz = sr->out.map_bufs_cnt;
+	sr->instr.ih.s.fsz = FDATA_SIZE + sizeof(struct gphdr);
+	sr->instr.ih.s.tlen = sr->instr.ih.s.fsz + sr->in.total_bytes;
+	sr->instr.ih.value = cpu_to_be64(sr->instr.ih.value);
+
+	/* word 2 */
+	sr->instr.irh.value[0] = 0;
+	sr->instr.irh.s.uddl = MIN_UDD_LEN;
+	/* context length in 64-bit words */
+	sr->instr.irh.s.ctxl = (req->ctrl.s.ctxl / 8);
+	/* offset from solicit base port 256 */
+	sr->instr.irh.s.destport = SOLICIT_BASE_DPORT + qno;
+	sr->instr.irh.s.ctxc = req->ctrl.s.ctxc;
+	sr->instr.irh.s.arg = req->ctrl.s.arg;
+	sr->instr.irh.s.opcode = req->opcode;
+	sr->instr.irh.value[0] = cpu_to_be64(sr->instr.irh.value[0]);
+
+	/* word 3 */
+	sr->instr.irh.s.ctxp = cpu_to_be64(ctx_handle);
+
+	/* word 4 */
+	sr->instr.slc.value[0] = 0;
+	sr->instr.slc.s.ssz = sr->out.map_bufs_cnt;
+	sr->instr.slc.value[0] = cpu_to_be64(sr->instr.slc.value[0]);
+
+	/* word 5 */
+	sr->instr.slc.s.rptr = cpu_to_be64(sr->out.dma);
+
+	/*
+	 * No conversion for front data,
+	 * It goes into payload
+	 * put GP Header in front data
+	 */
+	sr->instr.fdata[0] = *((u64 *)&req->gph);
+	sr->instr.fdata[1] = 0;
+
+	ret = nitrox_enqueue_request(sr);
+	if (ret == -ENOSPC)
+		goto send_fail;
+
+	return ret;
+
+send_fail:
+	softreq_destroy(sr);
+	return ret;
+}
+
+static inline int cmd_timeout(unsigned long tstamp, unsigned long timeout)
+{
+	return time_after_eq(jiffies, (tstamp + timeout));
+}
+
+void backlog_qflush_work(struct work_struct *work)
+{
+	struct nitrox_cmdq *cmdq;
+
+	cmdq = container_of(work, struct nitrox_cmdq, backlog_qflush);
+	post_backlog_cmds(cmdq);
+}
+
+/**
+ * process_request_list - process completed requests
+ * @ndev: N5 device
+ * @qno: queue to operate
+ *
+ * Returns the number of responses processed.
+ */
+static void process_response_list(struct nitrox_cmdq *cmdq)
+{
+	struct nitrox_device *ndev = cmdq->ndev;
+	struct nitrox_softreq *sr;
+	struct skcipher_request *skreq;
+	completion_t callback;
+	int req_completed = 0, err = 0, budget;
+
+	/* check all pending requests */
+	budget = atomic_read(&cmdq->pending_count);
+
+	while (req_completed < budget) {
+		sr = get_first_response_entry(cmdq);
+		if (!sr)
+			break;
+
+		if (atomic_read(&sr->status) != REQ_POSTED)
+			break;
+
+		/* check orh and completion bytes updates */
+		if (READ_ONCE(sr->resp.orh) == READ_ONCE(sr->resp.completion)) {
+			/* request not completed, check for timeout */
+			if (!cmd_timeout(sr->tstamp, ndev->timeout))
+				break;
+			dev_err_ratelimited(DEV(ndev),
+					    "Request timeout, orh 0x%016llx\n",
+					    READ_ONCE(sr->resp.orh));
+		}
+		atomic_dec(&cmdq->pending_count);
+		/* sync with other cpus */
+		smp_mb__after_atomic();
+		/* remove from response list */
+		response_list_del(sr, cmdq);
+
+		callback = sr->callback;
+		skreq = sr->skreq;
+
+		/* ORH error code */
+		err = READ_ONCE(sr->resp.orh) & 0xff;
+		softreq_destroy(sr);
+
+		if (callback)
+			callback(skreq, err);
+
+		req_completed++;
+	}
+}
+
+/**
+ * pkt_slc_resp_handler - post processing of SE responses
+ */
+void pkt_slc_resp_handler(unsigned long data)
+{
+	struct bh_data *bh = (void *)(uintptr_t)(data);
+	struct nitrox_cmdq *cmdq = bh->cmdq;
+	union nps_pkt_slc_cnts pkt_slc_cnts;
+
+	/* read completion count */
+	pkt_slc_cnts.value = readq(bh->completion_cnt_csr_addr);
+	/* resend the interrupt if more work to do */
+	pkt_slc_cnts.s.resend = 1;
+
+	process_response_list(cmdq);
+
+	/*
+	 * clear the interrupt with resend bit enabled,
+	 * MSI-X interrupt generates if Completion count > Threshold
+	 */
+	writeq(pkt_slc_cnts.value, bh->completion_cnt_csr_addr);
+	/* order the writes */
+	mmiowb();
+
+	if (atomic_read(&cmdq->backlog_count))
+		schedule_work(&cmdq->backlog_qflush);
+}