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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause2 3/* Authors: Bernard Metzler <bmt@zurich.ibm.com> */4/* Copyright (c) 2008-2019, IBM Corporation */5 6#include <linux/errno.h>7#include <linux/types.h>8#include <linux/net.h>9#include <linux/scatterlist.h>10#include <linux/highmem.h>11 12#include <rdma/iw_cm.h>13#include <rdma/ib_verbs.h>14 15#include "siw.h"16#include "siw_verbs.h"17#include "siw_mem.h"18 19/*20 * siw_rx_umem()21 *22 * Receive data of @len into target referenced by @dest_addr.23 *24 * @srx:	Receive Context25 * @umem:	siw representation of target memory26 * @dest_addr:	user virtual address27 * @len:	number of bytes to place28 */29static int siw_rx_umem(struct siw_rx_stream *srx, struct siw_umem *umem,30		       u64 dest_addr, int len)31{32	int copied = 0;33 34	while (len) {35		struct page *p;36		int pg_off, bytes, rv;37		void *dest;38 39		p = siw_get_upage(umem, dest_addr);40		if (unlikely(!p)) {41			pr_warn("siw: %s: [QP %u]: bogus addr: %pK, %pK\n",42				__func__, qp_id(rx_qp(srx)),43				(void *)(uintptr_t)dest_addr,44				(void *)(uintptr_t)umem->fp_addr);45			/* siw internal error */46			srx->skb_copied += copied;47			srx->skb_new -= copied;48 49			return -EFAULT;50		}51		pg_off = dest_addr & ~PAGE_MASK;52		bytes = min(len, (int)PAGE_SIZE - pg_off);53 54		siw_dbg_qp(rx_qp(srx), "page %pK, bytes=%u\n", p, bytes);55 56		dest = kmap_atomic(p);57		rv = skb_copy_bits(srx->skb, srx->skb_offset, dest + pg_off,58				   bytes);59 60		if (unlikely(rv)) {61			kunmap_atomic(dest);62			srx->skb_copied += copied;63			srx->skb_new -= copied;64 65			pr_warn("siw: [QP %u]: %s, len %d, page %p, rv %d\n",66				qp_id(rx_qp(srx)), __func__, len, p, rv);67 68			return -EFAULT;69		}70		if (srx->mpa_crc_hd) {71			if (rdma_is_kernel_res(&rx_qp(srx)->base_qp.res)) {72				crypto_shash_update(srx->mpa_crc_hd,73					(u8 *)(dest + pg_off), bytes);74				kunmap_atomic(dest);75			} else {76				kunmap_atomic(dest);77				/*78				 * Do CRC on original, not target buffer.79				 * Some user land applications may80				 * concurrently write the target buffer,81				 * which would yield a broken CRC.82				 * Walking the skb twice is very ineffcient.83				 * Folding the CRC into skb_copy_bits()84				 * would be much better, but is currently85				 * not supported.86				 */87				siw_crc_skb(srx, bytes);88			}89		} else {90			kunmap_atomic(dest);91		}92		srx->skb_offset += bytes;93		copied += bytes;94		len -= bytes;95		dest_addr += bytes;96		pg_off = 0;97	}98	srx->skb_copied += copied;99	srx->skb_new -= copied;100 101	return copied;102}103 104static int siw_rx_kva(struct siw_rx_stream *srx, void *kva, int len)105{106	int rv;107 108	siw_dbg_qp(rx_qp(srx), "kva: 0x%pK, len: %u\n", kva, len);109 110	rv = skb_copy_bits(srx->skb, srx->skb_offset, kva, len);111	if (unlikely(rv)) {112		pr_warn("siw: [QP %u]: %s, len %d, kva 0x%pK, rv %d\n",113			qp_id(rx_qp(srx)), __func__, len, kva, rv);114 115		return rv;116	}117	if (srx->mpa_crc_hd)118		crypto_shash_update(srx->mpa_crc_hd, (u8 *)kva, len);119 120	srx->skb_offset += len;121	srx->skb_copied += len;122	srx->skb_new -= len;123 124	return len;125}126 127static int siw_rx_pbl(struct siw_rx_stream *srx, int *pbl_idx,128		      struct siw_mem *mem, u64 addr, int len)129{130	struct siw_pbl *pbl = mem->pbl;131	u64 offset = addr - mem->va;132	int copied = 0;133 134	while (len) {135		int bytes;136		dma_addr_t buf_addr =137			siw_pbl_get_buffer(pbl, offset, &bytes, pbl_idx);138		if (!buf_addr)139			break;140 141		bytes = min(bytes, len);142		if (siw_rx_kva(srx, ib_virt_dma_to_ptr(buf_addr), bytes) ==143		    bytes) {144			copied += bytes;145			offset += bytes;146			len -= bytes;147		} else {148			break;149		}150	}151	return copied;152}153 154/*155 * siw_rresp_check_ntoh()156 *157 * Check incoming RRESP fragment header against expected158 * header values and update expected values for potential next159 * fragment.160 *161 * NOTE: This function must be called only if a RRESP DDP segment162 *       starts but not for fragmented consecutive pieces of an163 *       already started DDP segment.164 */165static int siw_rresp_check_ntoh(struct siw_rx_stream *srx,166				struct siw_rx_fpdu *frx)167{168	struct iwarp_rdma_rresp *rresp = &srx->hdr.rresp;169	struct siw_wqe *wqe = &frx->wqe_active;170	enum ddp_ecode ecode;171 172	u32 sink_stag = be32_to_cpu(rresp->sink_stag);173	u64 sink_to = be64_to_cpu(rresp->sink_to);174 175	if (frx->first_ddp_seg) {176		srx->ddp_stag = wqe->sqe.sge[0].lkey;177		srx->ddp_to = wqe->sqe.sge[0].laddr;178		frx->pbl_idx = 0;179	}180	/* Below checks extend beyond the semantics of DDP, and181	 * into RDMAP:182	 * We check if the read response matches exactly the183	 * read request which was send to the remote peer to184	 * trigger this read response. RFC5040/5041 do not185	 * always have a proper error code for the detected186	 * error cases. We choose 'base or bounds error' for187	 * cases where the inbound STag is valid, but offset188	 * or length do not match our response receive state.189	 */190	if (unlikely(srx->ddp_stag != sink_stag)) {191		pr_warn("siw: [QP %u]: rresp stag: %08x != %08x\n",192			qp_id(rx_qp(srx)), sink_stag, srx->ddp_stag);193		ecode = DDP_ECODE_T_INVALID_STAG;194		goto error;195	}196	if (unlikely(srx->ddp_to != sink_to)) {197		pr_warn("siw: [QP %u]: rresp off: %016llx != %016llx\n",198			qp_id(rx_qp(srx)), (unsigned long long)sink_to,199			(unsigned long long)srx->ddp_to);200		ecode = DDP_ECODE_T_BASE_BOUNDS;201		goto error;202	}203	if (unlikely(!frx->more_ddp_segs &&204		     (wqe->processed + srx->fpdu_part_rem != wqe->bytes))) {205		pr_warn("siw: [QP %u]: rresp len: %d != %d\n",206			qp_id(rx_qp(srx)),207			wqe->processed + srx->fpdu_part_rem, wqe->bytes);208		ecode = DDP_ECODE_T_BASE_BOUNDS;209		goto error;210	}211	return 0;212error:213	siw_init_terminate(rx_qp(srx), TERM_ERROR_LAYER_DDP,214			   DDP_ETYPE_TAGGED_BUF, ecode, 0);215	return -EINVAL;216}217 218/*219 * siw_write_check_ntoh()220 *221 * Check incoming WRITE fragment header against expected222 * header values and update expected values for potential next223 * fragment224 *225 * NOTE: This function must be called only if a WRITE DDP segment226 *       starts but not for fragmented consecutive pieces of an227 *       already started DDP segment.228 */229static int siw_write_check_ntoh(struct siw_rx_stream *srx,230				struct siw_rx_fpdu *frx)231{232	struct iwarp_rdma_write *write = &srx->hdr.rwrite;233	enum ddp_ecode ecode;234 235	u32 sink_stag = be32_to_cpu(write->sink_stag);236	u64 sink_to = be64_to_cpu(write->sink_to);237 238	if (frx->first_ddp_seg) {239		srx->ddp_stag = sink_stag;240		srx->ddp_to = sink_to;241		frx->pbl_idx = 0;242	} else {243		if (unlikely(srx->ddp_stag != sink_stag)) {244			pr_warn("siw: [QP %u]: write stag: %08x != %08x\n",245				qp_id(rx_qp(srx)), sink_stag,246				srx->ddp_stag);247			ecode = DDP_ECODE_T_INVALID_STAG;248			goto error;249		}250		if (unlikely(srx->ddp_to != sink_to)) {251			pr_warn("siw: [QP %u]: write off: %016llx != %016llx\n",252				qp_id(rx_qp(srx)),253				(unsigned long long)sink_to,254				(unsigned long long)srx->ddp_to);255			ecode = DDP_ECODE_T_BASE_BOUNDS;256			goto error;257		}258	}259	return 0;260error:261	siw_init_terminate(rx_qp(srx), TERM_ERROR_LAYER_DDP,262			   DDP_ETYPE_TAGGED_BUF, ecode, 0);263	return -EINVAL;264}265 266/*267 * siw_send_check_ntoh()268 *269 * Check incoming SEND fragment header against expected270 * header values and update expected MSN if no next271 * fragment expected272 *273 * NOTE: This function must be called only if a SEND DDP segment274 *       starts but not for fragmented consecutive pieces of an275 *       already started DDP segment.276 */277static int siw_send_check_ntoh(struct siw_rx_stream *srx,278			       struct siw_rx_fpdu *frx)279{280	struct iwarp_send_inv *send = &srx->hdr.send_inv;281	struct siw_wqe *wqe = &frx->wqe_active;282	enum ddp_ecode ecode;283 284	u32 ddp_msn = be32_to_cpu(send->ddp_msn);285	u32 ddp_mo = be32_to_cpu(send->ddp_mo);286	u32 ddp_qn = be32_to_cpu(send->ddp_qn);287 288	if (unlikely(ddp_qn != RDMAP_UNTAGGED_QN_SEND)) {289		pr_warn("siw: [QP %u]: invalid ddp qn %d for send\n",290			qp_id(rx_qp(srx)), ddp_qn);291		ecode = DDP_ECODE_UT_INVALID_QN;292		goto error;293	}294	if (unlikely(ddp_msn != srx->ddp_msn[RDMAP_UNTAGGED_QN_SEND])) {295		pr_warn("siw: [QP %u]: send msn: %u != %u\n",296			qp_id(rx_qp(srx)), ddp_msn,297			srx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]);298		ecode = DDP_ECODE_UT_INVALID_MSN_RANGE;299		goto error;300	}301	if (unlikely(ddp_mo != wqe->processed)) {302		pr_warn("siw: [QP %u], send mo: %u != %u\n",303			qp_id(rx_qp(srx)), ddp_mo, wqe->processed);304		ecode = DDP_ECODE_UT_INVALID_MO;305		goto error;306	}307	if (frx->first_ddp_seg) {308		/* initialize user memory write position */309		frx->sge_idx = 0;310		frx->sge_off = 0;311		frx->pbl_idx = 0;312 313		/* only valid for SEND_INV and SEND_SE_INV operations */314		srx->inval_stag = be32_to_cpu(send->inval_stag);315	}316	if (unlikely(wqe->bytes < wqe->processed + srx->fpdu_part_rem)) {317		siw_dbg_qp(rx_qp(srx), "receive space short: %d - %d < %d\n",318			   wqe->bytes, wqe->processed, srx->fpdu_part_rem);319		wqe->wc_status = SIW_WC_LOC_LEN_ERR;320		ecode = DDP_ECODE_UT_INVALID_MSN_NOBUF;321		goto error;322	}323	return 0;324error:325	siw_init_terminate(rx_qp(srx), TERM_ERROR_LAYER_DDP,326			   DDP_ETYPE_UNTAGGED_BUF, ecode, 0);327	return -EINVAL;328}329 330static struct siw_wqe *siw_rqe_get(struct siw_qp *qp)331{332	struct siw_rqe *rqe;333	struct siw_srq *srq;334	struct siw_wqe *wqe = NULL;335	bool srq_event = false;336	unsigned long flags;337 338	srq = qp->srq;339	if (srq) {340		spin_lock_irqsave(&srq->lock, flags);341		if (unlikely(!srq->num_rqe))342			goto out;343 344		rqe = &srq->recvq[srq->rq_get % srq->num_rqe];345	} else {346		if (unlikely(!qp->recvq))347			goto out;348 349		rqe = &qp->recvq[qp->rq_get % qp->attrs.rq_size];350	}351	if (likely(rqe->flags == SIW_WQE_VALID)) {352		int num_sge = rqe->num_sge;353 354		if (likely(num_sge <= SIW_MAX_SGE)) {355			int i = 0;356 357			wqe = rx_wqe(&qp->rx_untagged);358			rx_type(wqe) = SIW_OP_RECEIVE;359			wqe->wr_status = SIW_WR_INPROGRESS;360			wqe->bytes = 0;361			wqe->processed = 0;362 363			wqe->rqe.id = rqe->id;364			wqe->rqe.num_sge = num_sge;365 366			while (i < num_sge) {367				wqe->rqe.sge[i].laddr = rqe->sge[i].laddr;368				wqe->rqe.sge[i].lkey = rqe->sge[i].lkey;369				wqe->rqe.sge[i].length = rqe->sge[i].length;370				wqe->bytes += wqe->rqe.sge[i].length;371				wqe->mem[i] = NULL;372				i++;373			}374			/* can be re-used by appl */375			smp_store_mb(rqe->flags, 0);376		} else {377			siw_dbg_qp(qp, "too many sge's: %d\n", rqe->num_sge);378			if (srq)379				spin_unlock_irqrestore(&srq->lock, flags);380			return NULL;381		}382		if (!srq) {383			qp->rq_get++;384		} else {385			if (srq->armed) {386				/* Test SRQ limit */387				u32 off = (srq->rq_get + srq->limit) %388					  srq->num_rqe;389				struct siw_rqe *rqe2 = &srq->recvq[off];390 391				if (!(rqe2->flags & SIW_WQE_VALID)) {392					srq->armed = false;393					srq_event = true;394				}395			}396			srq->rq_get++;397		}398	}399out:400	if (srq) {401		spin_unlock_irqrestore(&srq->lock, flags);402		if (srq_event)403			siw_srq_event(srq, IB_EVENT_SRQ_LIMIT_REACHED);404	}405	return wqe;406}407 408static int siw_rx_data(struct siw_mem *mem_p, struct siw_rx_stream *srx,409		       unsigned int *pbl_idx, u64 addr, int bytes)410{411	int rv;412 413	if (mem_p->mem_obj == NULL)414		rv = siw_rx_kva(srx, ib_virt_dma_to_ptr(addr), bytes);415	else if (!mem_p->is_pbl)416		rv = siw_rx_umem(srx, mem_p->umem, addr, bytes);417	else418		rv = siw_rx_pbl(srx, pbl_idx, mem_p, addr, bytes);419	return rv;420}421 422/*423 * siw_proc_send:424 *425 * Process one incoming SEND and place data into memory referenced by426 * receive wqe.427 *428 * Function supports partially received sends (suspending/resuming429 * current receive wqe processing)430 *431 * return value:432 *	0:       reached the end of a DDP segment433 *	-EAGAIN: to be called again to finish the DDP segment434 */435int siw_proc_send(struct siw_qp *qp)436{437	struct siw_rx_stream *srx = &qp->rx_stream;438	struct siw_rx_fpdu *frx = &qp->rx_untagged;439	struct siw_wqe *wqe;440	u32 data_bytes; /* all data bytes available */441	u32 rcvd_bytes; /* sum of data bytes rcvd */442	int rv = 0;443 444	if (frx->first_ddp_seg) {445		wqe = siw_rqe_get(qp);446		if (unlikely(!wqe)) {447			siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,448					   DDP_ETYPE_UNTAGGED_BUF,449					   DDP_ECODE_UT_INVALID_MSN_NOBUF, 0);450			return -ENOENT;451		}452	} else {453		wqe = rx_wqe(frx);454	}455	if (srx->state == SIW_GET_DATA_START) {456		rv = siw_send_check_ntoh(srx, frx);457		if (unlikely(rv)) {458			siw_qp_event(qp, IB_EVENT_QP_FATAL);459			return rv;460		}461		if (!srx->fpdu_part_rem) /* zero length SEND */462			return 0;463	}464	data_bytes = min(srx->fpdu_part_rem, srx->skb_new);465	rcvd_bytes = 0;466 467	/* A zero length SEND will skip below loop */468	while (data_bytes) {469		struct ib_pd *pd;470		struct siw_mem **mem, *mem_p;471		struct siw_sge *sge;472		u32 sge_bytes; /* data bytes avail for SGE */473 474		sge = &wqe->rqe.sge[frx->sge_idx];475 476		if (!sge->length) {477			/* just skip empty sge's */478			frx->sge_idx++;479			frx->sge_off = 0;480			frx->pbl_idx = 0;481			continue;482		}483		sge_bytes = min(data_bytes, sge->length - frx->sge_off);484		mem = &wqe->mem[frx->sge_idx];485 486		/*487		 * check with QP's PD if no SRQ present, SRQ's PD otherwise488		 */489		pd = qp->srq == NULL ? qp->pd : qp->srq->base_srq.pd;490 491		rv = siw_check_sge(pd, sge, mem, IB_ACCESS_LOCAL_WRITE,492				   frx->sge_off, sge_bytes);493		if (unlikely(rv)) {494			siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,495					   DDP_ETYPE_CATASTROPHIC,496					   DDP_ECODE_CATASTROPHIC, 0);497 498			siw_qp_event(qp, IB_EVENT_QP_ACCESS_ERR);499			break;500		}501		mem_p = *mem;502		rv = siw_rx_data(mem_p, srx, &frx->pbl_idx,503				 sge->laddr + frx->sge_off, sge_bytes);504		if (unlikely(rv != sge_bytes)) {505			wqe->processed += rcvd_bytes;506 507			siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,508					   DDP_ETYPE_CATASTROPHIC,509					   DDP_ECODE_CATASTROPHIC, 0);510			return -EINVAL;511		}512		frx->sge_off += rv;513 514		if (frx->sge_off == sge->length) {515			frx->sge_idx++;516			frx->sge_off = 0;517			frx->pbl_idx = 0;518		}519		data_bytes -= rv;520		rcvd_bytes += rv;521 522		srx->fpdu_part_rem -= rv;523		srx->fpdu_part_rcvd += rv;524	}525	wqe->processed += rcvd_bytes;526 527	if (!srx->fpdu_part_rem)528		return 0;529 530	return (rv < 0) ? rv : -EAGAIN;531}532 533/*534 * siw_proc_write:535 *536 * Place incoming WRITE after referencing and checking target buffer537 538 * Function supports partially received WRITEs (suspending/resuming539 * current receive processing)540 *541 * return value:542 *	0:       reached the end of a DDP segment543 *	-EAGAIN: to be called again to finish the DDP segment544 */545int siw_proc_write(struct siw_qp *qp)546{547	struct siw_rx_stream *srx = &qp->rx_stream;548	struct siw_rx_fpdu *frx = &qp->rx_tagged;549	struct siw_mem *mem;550	int bytes, rv;551 552	if (srx->state == SIW_GET_DATA_START) {553		if (!srx->fpdu_part_rem) /* zero length WRITE */554			return 0;555 556		rv = siw_write_check_ntoh(srx, frx);557		if (unlikely(rv)) {558			siw_qp_event(qp, IB_EVENT_QP_FATAL);559			return rv;560		}561	}562	bytes = min(srx->fpdu_part_rem, srx->skb_new);563 564	if (frx->first_ddp_seg) {565		struct siw_wqe *wqe = rx_wqe(frx);566 567		rx_mem(frx) = siw_mem_id2obj(qp->sdev, srx->ddp_stag >> 8);568		if (unlikely(!rx_mem(frx))) {569			siw_dbg_qp(qp,570				   "sink stag not found/invalid, stag 0x%08x\n",571				   srx->ddp_stag);572 573			siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,574					   DDP_ETYPE_TAGGED_BUF,575					   DDP_ECODE_T_INVALID_STAG, 0);576			return -EINVAL;577		}578		wqe->rqe.num_sge = 1;579		rx_type(wqe) = SIW_OP_WRITE;580		wqe->wr_status = SIW_WR_INPROGRESS;581	}582	mem = rx_mem(frx);583 584	/*585	 * Check if application re-registered memory with different586	 * key field of STag.587	 */588	if (unlikely(mem->stag != srx->ddp_stag)) {589		siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,590				   DDP_ETYPE_TAGGED_BUF,591				   DDP_ECODE_T_INVALID_STAG, 0);592		return -EINVAL;593	}594	rv = siw_check_mem(qp->pd, mem, srx->ddp_to + srx->fpdu_part_rcvd,595			   IB_ACCESS_REMOTE_WRITE, bytes);596	if (unlikely(rv)) {597		siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,598				   DDP_ETYPE_TAGGED_BUF, siw_tagged_error(-rv),599				   0);600 601		siw_qp_event(qp, IB_EVENT_QP_ACCESS_ERR);602 603		return -EINVAL;604	}605 606	rv = siw_rx_data(mem, srx, &frx->pbl_idx,607			 srx->ddp_to + srx->fpdu_part_rcvd, bytes);608	if (unlikely(rv != bytes)) {609		siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,610				   DDP_ETYPE_CATASTROPHIC,611				   DDP_ECODE_CATASTROPHIC, 0);612		return -EINVAL;613	}614	srx->fpdu_part_rem -= rv;615	srx->fpdu_part_rcvd += rv;616 617	if (!srx->fpdu_part_rem) {618		srx->ddp_to += srx->fpdu_part_rcvd;619		return 0;620	}621	return -EAGAIN;622}623 624/*625 * Inbound RREQ's cannot carry user data.626 */627int siw_proc_rreq(struct siw_qp *qp)628{629	struct siw_rx_stream *srx = &qp->rx_stream;630 631	if (!srx->fpdu_part_rem)632		return 0;633 634	pr_warn("siw: [QP %u]: rreq with mpa len %d\n", qp_id(qp),635		be16_to_cpu(srx->hdr.ctrl.mpa_len));636 637	return -EPROTO;638}639 640/*641 * siw_init_rresp:642 *643 * Process inbound RDMA READ REQ. Produce a pseudo READ RESPONSE WQE.644 * Put it at the tail of the IRQ, if there is another WQE currently in645 * transmit processing. If not, make it the current WQE to be processed646 * and schedule transmit processing.647 *648 * Can be called from softirq context and from process649 * context (RREAD socket loopback case!)650 *651 * return value:652 *	0:      success,653 *		failure code otherwise654 */655 656static int siw_init_rresp(struct siw_qp *qp, struct siw_rx_stream *srx)657{658	struct siw_wqe *tx_work = tx_wqe(qp);659	struct siw_sqe *resp;660 661	uint64_t raddr = be64_to_cpu(srx->hdr.rreq.sink_to),662		 laddr = be64_to_cpu(srx->hdr.rreq.source_to);663	uint32_t length = be32_to_cpu(srx->hdr.rreq.read_size),664		 lkey = be32_to_cpu(srx->hdr.rreq.source_stag),665		 rkey = be32_to_cpu(srx->hdr.rreq.sink_stag),666		 msn = be32_to_cpu(srx->hdr.rreq.ddp_msn);667 668	int run_sq = 1, rv = 0;669	unsigned long flags;670 671	if (unlikely(msn != srx->ddp_msn[RDMAP_UNTAGGED_QN_RDMA_READ])) {672		siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,673				   DDP_ETYPE_UNTAGGED_BUF,674				   DDP_ECODE_UT_INVALID_MSN_RANGE, 0);675		return -EPROTO;676	}677	spin_lock_irqsave(&qp->sq_lock, flags);678 679	if (unlikely(!qp->attrs.irq_size)) {680		run_sq = 0;681		goto error_irq;682	}683	if (tx_work->wr_status == SIW_WR_IDLE) {684		/*685		 * immediately schedule READ response w/o686		 * consuming IRQ entry: IRQ must be empty.687		 */688		tx_work->processed = 0;689		tx_work->mem[0] = NULL;690		tx_work->wr_status = SIW_WR_QUEUED;691		resp = &tx_work->sqe;692	} else {693		resp = irq_alloc_free(qp);694		run_sq = 0;695	}696	if (likely(resp)) {697		resp->opcode = SIW_OP_READ_RESPONSE;698 699		resp->sge[0].length = length;700		resp->sge[0].laddr = laddr;701		resp->sge[0].lkey = lkey;702 703		/* Keep aside message sequence number for potential704		 * error reporting during Read Response generation.705		 */706		resp->sge[1].length = msn;707 708		resp->raddr = raddr;709		resp->rkey = rkey;710		resp->num_sge = length ? 1 : 0;711 712		/* RRESP now valid as current TX wqe or placed into IRQ */713		smp_store_mb(resp->flags, SIW_WQE_VALID);714	} else {715error_irq:716		pr_warn("siw: [QP %u]: IRQ exceeded or null, size %d\n",717			qp_id(qp), qp->attrs.irq_size);718 719		siw_init_terminate(qp, TERM_ERROR_LAYER_RDMAP,720				   RDMAP_ETYPE_REMOTE_OPERATION,721				   RDMAP_ECODE_CATASTROPHIC_STREAM, 0);722		rv = -EPROTO;723	}724 725	spin_unlock_irqrestore(&qp->sq_lock, flags);726 727	if (run_sq)728		rv = siw_sq_start(qp);729 730	return rv;731}732 733/*734 * Only called at start of Read.Resonse processing.735 * Transfer pending Read from tip of ORQ into currrent rx wqe,736 * but keep ORQ entry valid until Read.Response processing done.737 * No Queue locking needed.738 */739static int siw_orqe_start_rx(struct siw_qp *qp)740{741	struct siw_sqe *orqe;742	struct siw_wqe *wqe = NULL;743 744	if (unlikely(!qp->attrs.orq_size))745		return -EPROTO;746 747	/* make sure ORQ indices are current */748	smp_mb();749 750	orqe = orq_get_current(qp);751	if (READ_ONCE(orqe->flags) & SIW_WQE_VALID) {752		/* RRESP is a TAGGED RDMAP operation */753		wqe = rx_wqe(&qp->rx_tagged);754		wqe->sqe.id = orqe->id;755		wqe->sqe.opcode = orqe->opcode;756		wqe->sqe.sge[0].laddr = orqe->sge[0].laddr;757		wqe->sqe.sge[0].lkey = orqe->sge[0].lkey;758		wqe->sqe.sge[0].length = orqe->sge[0].length;759		wqe->sqe.flags = orqe->flags;760		wqe->sqe.num_sge = 1;761		wqe->bytes = orqe->sge[0].length;762		wqe->processed = 0;763		wqe->mem[0] = NULL;764		/* make sure WQE is completely written before valid */765		smp_wmb();766		wqe->wr_status = SIW_WR_INPROGRESS;767 768		return 0;769	}770	return -EPROTO;771}772 773/*774 * siw_proc_rresp:775 *776 * Place incoming RRESP data into memory referenced by RREQ WQE777 * which is at the tip of the ORQ778 *779 * Function supports partially received RRESP's (suspending/resuming780 * current receive processing)781 */782int siw_proc_rresp(struct siw_qp *qp)783{784	struct siw_rx_stream *srx = &qp->rx_stream;785	struct siw_rx_fpdu *frx = &qp->rx_tagged;786	struct siw_wqe *wqe = rx_wqe(frx);787	struct siw_mem **mem, *mem_p;788	struct siw_sge *sge;789	int bytes, rv;790 791	if (frx->first_ddp_seg) {792		if (unlikely(wqe->wr_status != SIW_WR_IDLE)) {793			pr_warn("siw: [QP %u]: proc RRESP: status %d, op %d\n",794				qp_id(qp), wqe->wr_status, wqe->sqe.opcode);795			rv = -EPROTO;796			goto error_term;797		}798		/*799		 * fetch pending RREQ from orq800		 */801		rv = siw_orqe_start_rx(qp);802		if (rv) {803			pr_warn("siw: [QP %u]: ORQ empty, size %d\n",804				qp_id(qp), qp->attrs.orq_size);805			goto error_term;806		}807		rv = siw_rresp_check_ntoh(srx, frx);808		if (unlikely(rv)) {809			siw_qp_event(qp, IB_EVENT_QP_FATAL);810			return rv;811		}812	} else {813		if (unlikely(wqe->wr_status != SIW_WR_INPROGRESS)) {814			pr_warn("siw: [QP %u]: resume RRESP: status %d\n",815				qp_id(qp), wqe->wr_status);816			rv = -EPROTO;817			goto error_term;818		}819	}820	if (!srx->fpdu_part_rem) /* zero length RRESPONSE */821		return 0;822 823	sge = wqe->sqe.sge; /* there is only one */824	mem = &wqe->mem[0];825 826	if (!(*mem)) {827		/*828		 * check target memory which resolves memory on first fragment829		 */830		rv = siw_check_sge(qp->pd, sge, mem, IB_ACCESS_LOCAL_WRITE, 0,831				   wqe->bytes);832		if (unlikely(rv)) {833			siw_dbg_qp(qp, "target mem check: %d\n", rv);834			wqe->wc_status = SIW_WC_LOC_PROT_ERR;835 836			siw_init_terminate(qp, TERM_ERROR_LAYER_DDP,837					   DDP_ETYPE_TAGGED_BUF,838					   siw_tagged_error(-rv), 0);839 840			siw_qp_event(qp, IB_EVENT_QP_ACCESS_ERR);841 842			return -EINVAL;843		}844	}845	mem_p = *mem;846 847	bytes = min(srx->fpdu_part_rem, srx->skb_new);848	rv = siw_rx_data(mem_p, srx, &frx->pbl_idx,849			 sge->laddr + wqe->processed, bytes);850	if (rv != bytes) {851		wqe->wc_status = SIW_WC_GENERAL_ERR;852		rv = -EINVAL;853		goto error_term;854	}855	srx->fpdu_part_rem -= rv;856	srx->fpdu_part_rcvd += rv;857	wqe->processed += rv;858 859	if (!srx->fpdu_part_rem) {860		srx->ddp_to += srx->fpdu_part_rcvd;861		return 0;862	}863	return -EAGAIN;864 865error_term:866	siw_init_terminate(qp, TERM_ERROR_LAYER_DDP, DDP_ETYPE_CATASTROPHIC,867			   DDP_ECODE_CATASTROPHIC, 0);868	return rv;869}870 871static void siw_update_skb_rcvd(struct siw_rx_stream *srx, u16 length)872{873	srx->skb_offset += length;874	srx->skb_new -= length;875	srx->skb_copied += length;876}877 878int siw_proc_terminate(struct siw_qp *qp)879{880	struct siw_rx_stream *srx = &qp->rx_stream;881	struct sk_buff *skb = srx->skb;882	struct iwarp_terminate *term = &srx->hdr.terminate;883	union iwarp_hdr term_info;884	u8 *infop = (u8 *)&term_info;885	enum rdma_opcode op;886	u16 to_copy = sizeof(struct iwarp_ctrl);887 888	pr_warn("siw: got TERMINATE. layer %d, type %d, code %d\n",889		__rdmap_term_layer(term), __rdmap_term_etype(term),890		__rdmap_term_ecode(term));891 892	if (be32_to_cpu(term->ddp_qn) != RDMAP_UNTAGGED_QN_TERMINATE ||893	    be32_to_cpu(term->ddp_msn) !=894		    qp->rx_stream.ddp_msn[RDMAP_UNTAGGED_QN_TERMINATE] ||895	    be32_to_cpu(term->ddp_mo) != 0) {896		pr_warn("siw: rx bogus TERM [QN x%08x, MSN x%08x, MO x%08x]\n",897			be32_to_cpu(term->ddp_qn), be32_to_cpu(term->ddp_msn),898			be32_to_cpu(term->ddp_mo));899		return -ECONNRESET;900	}901	/*902	 * Receive remaining pieces of TERM if indicated903	 */904	if (!term->flag_m)905		return -ECONNRESET;906 907	/* Do not take the effort to reassemble a network fragmented908	 * TERM message909	 */910	if (srx->skb_new < sizeof(struct iwarp_ctrl_tagged))911		return -ECONNRESET;912 913	memset(infop, 0, sizeof(term_info));914 915	skb_copy_bits(skb, srx->skb_offset, infop, to_copy);916 917	op = __rdmap_get_opcode(&term_info.ctrl);918	if (op >= RDMAP_TERMINATE)919		goto out;920 921	infop += to_copy;922	siw_update_skb_rcvd(srx, to_copy);923	srx->fpdu_part_rcvd += to_copy;924	srx->fpdu_part_rem -= to_copy;925 926	to_copy = iwarp_pktinfo[op].hdr_len - to_copy;927 928	/* Again, no network fragmented TERM's */929	if (to_copy + MPA_CRC_SIZE > srx->skb_new)930		return -ECONNRESET;931 932	skb_copy_bits(skb, srx->skb_offset, infop, to_copy);933 934	if (term->flag_r) {935		siw_dbg_qp(qp, "TERM reports RDMAP hdr type %u, len %u (%s)\n",936			   op, be16_to_cpu(term_info.ctrl.mpa_len),937			   term->flag_m ? "valid" : "invalid");938	} else if (term->flag_d) {939		siw_dbg_qp(qp, "TERM reports DDP hdr type %u, len %u (%s)\n",940			   op, be16_to_cpu(term_info.ctrl.mpa_len),941			   term->flag_m ? "valid" : "invalid");942	}943out:944	siw_update_skb_rcvd(srx, to_copy);945	srx->fpdu_part_rcvd += to_copy;946	srx->fpdu_part_rem -= to_copy;947 948	return -ECONNRESET;949}950 951static int siw_get_trailer(struct siw_qp *qp, struct siw_rx_stream *srx)952{953	struct sk_buff *skb = srx->skb;954	int avail = min(srx->skb_new, srx->fpdu_part_rem);955	u8 *tbuf = (u8 *)&srx->trailer.crc - srx->pad;956	__wsum crc_in, crc_own = 0;957 958	siw_dbg_qp(qp, "expected %d, available %d, pad %u\n",959		   srx->fpdu_part_rem, srx->skb_new, srx->pad);960 961	skb_copy_bits(skb, srx->skb_offset, tbuf, avail);962 963	siw_update_skb_rcvd(srx, avail);964	srx->fpdu_part_rem -= avail;965 966	if (srx->fpdu_part_rem)967		return -EAGAIN;968 969	if (!srx->mpa_crc_hd)970		return 0;971 972	if (srx->pad)973		crypto_shash_update(srx->mpa_crc_hd, tbuf, srx->pad);974	/*975	 * CRC32 is computed, transmitted and received directly in NBO,976	 * so there's never a reason to convert byte order.977	 */978	crypto_shash_final(srx->mpa_crc_hd, (u8 *)&crc_own);979	crc_in = (__force __wsum)srx->trailer.crc;980 981	if (unlikely(crc_in != crc_own)) {982		pr_warn("siw: crc error. in: %08x, own %08x, op %u\n",983			crc_in, crc_own, qp->rx_stream.rdmap_op);984 985		siw_init_terminate(qp, TERM_ERROR_LAYER_LLP,986				   LLP_ETYPE_MPA,987				   LLP_ECODE_RECEIVED_CRC, 0);988		return -EINVAL;989	}990	return 0;991}992 993#define MIN_DDP_HDR sizeof(struct iwarp_ctrl_tagged)994 995static int siw_get_hdr(struct siw_rx_stream *srx)996{997	struct sk_buff *skb = srx->skb;998	struct siw_qp *qp = rx_qp(srx);999	struct iwarp_ctrl *c_hdr = &srx->hdr.ctrl;1000	struct siw_rx_fpdu *frx;1001	u8 opcode;1002	int bytes;1003 1004	if (srx->fpdu_part_rcvd < MIN_DDP_HDR) {1005		/*1006		 * copy a mimimum sized (tagged) DDP frame control part1007		 */1008		bytes = min_t(int, srx->skb_new,1009			      MIN_DDP_HDR - srx->fpdu_part_rcvd);1010 1011		skb_copy_bits(skb, srx->skb_offset,1012			      (char *)c_hdr + srx->fpdu_part_rcvd, bytes);1013 1014		siw_update_skb_rcvd(srx, bytes);1015		srx->fpdu_part_rcvd += bytes;1016		if (srx->fpdu_part_rcvd < MIN_DDP_HDR)1017			return -EAGAIN;1018 1019		if (unlikely(__ddp_get_version(c_hdr) != DDP_VERSION)) {1020			enum ddp_etype etype;1021			enum ddp_ecode ecode;1022 1023			pr_warn("siw: received ddp version unsupported %d\n",1024				__ddp_get_version(c_hdr));1025 1026			if (c_hdr->ddp_rdmap_ctrl & DDP_FLAG_TAGGED) {1027				etype = DDP_ETYPE_TAGGED_BUF;1028				ecode = DDP_ECODE_T_VERSION;1029			} else {1030				etype = DDP_ETYPE_UNTAGGED_BUF;1031				ecode = DDP_ECODE_UT_VERSION;1032			}1033			siw_init_terminate(rx_qp(srx), TERM_ERROR_LAYER_DDP,1034					   etype, ecode, 0);1035			return -EINVAL;1036		}1037		if (unlikely(__rdmap_get_version(c_hdr) != RDMAP_VERSION)) {1038			pr_warn("siw: received rdmap version unsupported %d\n",1039				__rdmap_get_version(c_hdr));1040 1041			siw_init_terminate(rx_qp(srx), TERM_ERROR_LAYER_RDMAP,1042					   RDMAP_ETYPE_REMOTE_OPERATION,1043					   RDMAP_ECODE_VERSION, 0);1044			return -EINVAL;1045		}1046		opcode = __rdmap_get_opcode(c_hdr);1047 1048		if (opcode > RDMAP_TERMINATE) {1049			pr_warn("siw: received unknown packet type %u\n",1050				opcode);1051 1052			siw_init_terminate(rx_qp(srx), TERM_ERROR_LAYER_RDMAP,1053					   RDMAP_ETYPE_REMOTE_OPERATION,1054					   RDMAP_ECODE_OPCODE, 0);1055			return -EINVAL;1056		}1057		siw_dbg_qp(rx_qp(srx), "new header, opcode %u\n", opcode);1058	} else {1059		opcode = __rdmap_get_opcode(c_hdr);1060	}1061	set_rx_fpdu_context(qp, opcode);1062	frx = qp->rx_fpdu;1063 1064	/*1065	 * Figure out len of current hdr: variable length of1066	 * iwarp hdr may force us to copy hdr information in1067	 * two steps. Only tagged DDP messages are already1068	 * completely received.1069	 */1070	if (iwarp_pktinfo[opcode].hdr_len > sizeof(struct iwarp_ctrl_tagged)) {1071		int hdrlen = iwarp_pktinfo[opcode].hdr_len;1072 1073		bytes = min_t(int, hdrlen - MIN_DDP_HDR, srx->skb_new);1074 1075		skb_copy_bits(skb, srx->skb_offset,1076			      (char *)c_hdr + srx->fpdu_part_rcvd, bytes);1077 1078		siw_update_skb_rcvd(srx, bytes);1079		srx->fpdu_part_rcvd += bytes;1080		if (srx->fpdu_part_rcvd < hdrlen)1081			return -EAGAIN;1082	}1083 1084	/*1085	 * DDP/RDMAP header receive completed. Check if the current1086	 * DDP segment starts a new RDMAP message or continues a previously1087	 * started RDMAP message.1088	 *1089	 * Alternating reception of DDP segments (or FPDUs) from incomplete1090	 * tagged and untagged RDMAP messages is supported, as long as1091	 * the current tagged or untagged message gets eventually completed1092	 * w/o intersection from another message of the same type1093	 * (tagged/untagged). E.g., a WRITE can get intersected by a SEND,1094	 * but not by a READ RESPONSE etc.1095	 */1096	if (srx->mpa_crc_hd) {1097		/*1098		 * Restart CRC computation1099		 */1100		crypto_shash_init(srx->mpa_crc_hd);1101		crypto_shash_update(srx->mpa_crc_hd, (u8 *)c_hdr,1102				    srx->fpdu_part_rcvd);1103	}1104	if (frx->more_ddp_segs) {1105		frx->first_ddp_seg = 0;1106		if (frx->prev_rdmap_op != opcode) {1107			pr_warn("siw: packet intersection: %u : %u\n",1108				frx->prev_rdmap_op, opcode);1109			/*1110			 * The last inbound RDMA operation of same type1111			 * (tagged or untagged) is left unfinished.1112			 * To complete it in error, make it the current1113			 * operation again, even with the header already1114			 * overwritten. For error handling, only the opcode1115			 * and current rx context are relevant.1116			 */1117			set_rx_fpdu_context(qp, frx->prev_rdmap_op);1118			__rdmap_set_opcode(c_hdr, frx->prev_rdmap_op);1119			return -EPROTO;1120		}1121	} else {1122		frx->prev_rdmap_op = opcode;1123		frx->first_ddp_seg = 1;1124	}1125	frx->more_ddp_segs = c_hdr->ddp_rdmap_ctrl & DDP_FLAG_LAST ? 0 : 1;1126 1127	return 0;1128}1129 1130static int siw_check_tx_fence(struct siw_qp *qp)1131{1132	struct siw_wqe *tx_waiting = tx_wqe(qp);1133	struct siw_sqe *rreq;1134	int resume_tx = 0, rv = 0;1135	unsigned long flags;1136 1137	spin_lock_irqsave(&qp->orq_lock, flags);1138 1139	/* free current orq entry */1140	rreq = orq_get_current(qp);1141	WRITE_ONCE(rreq->flags, 0);1142 1143	qp->orq_get++;1144 1145	if (qp->tx_ctx.orq_fence) {1146		if (unlikely(tx_waiting->wr_status != SIW_WR_QUEUED)) {1147			pr_warn("siw: [QP %u]: fence resume: bad status %d\n",1148				qp_id(qp), tx_waiting->wr_status);1149			rv = -EPROTO;1150			goto out;1151		}1152		/* resume SQ processing, if possible */1153		if (tx_waiting->sqe.opcode == SIW_OP_READ ||1154		    tx_waiting->sqe.opcode == SIW_OP_READ_LOCAL_INV) {1155 1156			/* SQ processing was stopped because of a full ORQ */1157			rreq = orq_get_free(qp);1158			if (unlikely(!rreq)) {1159				pr_warn("siw: [QP %u]: no ORQE\n", qp_id(qp));1160				rv = -EPROTO;1161				goto out;1162			}1163			siw_read_to_orq(rreq, &tx_waiting->sqe);1164 1165			qp->orq_put++;1166			qp->tx_ctx.orq_fence = 0;1167			resume_tx = 1;1168 1169		} else if (siw_orq_empty(qp)) {1170			/*1171			 * SQ processing was stopped by fenced work request.1172			 * Resume since all previous Read's are now completed.1173			 */1174			qp->tx_ctx.orq_fence = 0;1175			resume_tx = 1;1176		}1177	}1178out:1179	spin_unlock_irqrestore(&qp->orq_lock, flags);1180 1181	if (resume_tx)1182		rv = siw_sq_start(qp);1183 1184	return rv;1185}1186 1187/*1188 * siw_rdmap_complete()1189 *1190 * Complete processing of an RDMA message after receiving all1191 * DDP segmens or ABort processing after encountering error case.1192 *1193 *   o SENDs + RRESPs will need for completion,1194 *   o RREQs need for  READ RESPONSE initialization1195 *   o WRITEs need memory dereferencing1196 *1197 * TODO: Failed WRITEs need local error to be surfaced.1198 */1199static int siw_rdmap_complete(struct siw_qp *qp, int error)1200{1201	struct siw_rx_stream *srx = &qp->rx_stream;1202	struct siw_wqe *wqe = rx_wqe(qp->rx_fpdu);1203	enum siw_wc_status wc_status = wqe->wc_status;1204	u8 opcode = __rdmap_get_opcode(&srx->hdr.ctrl);1205	int rv = 0;1206 1207	switch (opcode) {1208	case RDMAP_SEND_SE:1209	case RDMAP_SEND_SE_INVAL:1210		wqe->rqe.flags |= SIW_WQE_SOLICITED;1211		fallthrough;1212 1213	case RDMAP_SEND:1214	case RDMAP_SEND_INVAL:1215		if (wqe->wr_status == SIW_WR_IDLE)1216			break;1217 1218		srx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]++;1219 1220		if (error != 0 && wc_status == SIW_WC_SUCCESS)1221			wc_status = SIW_WC_GENERAL_ERR;1222		/*1223		 * Handle STag invalidation request1224		 */1225		if (wc_status == SIW_WC_SUCCESS &&1226		    (opcode == RDMAP_SEND_INVAL ||1227		     opcode == RDMAP_SEND_SE_INVAL)) {1228			rv = siw_invalidate_stag(qp->pd, srx->inval_stag);1229			if (rv) {1230				siw_init_terminate(1231					qp, TERM_ERROR_LAYER_RDMAP,1232					rv == -EACCES ?1233						RDMAP_ETYPE_REMOTE_PROTECTION :1234						RDMAP_ETYPE_REMOTE_OPERATION,1235					RDMAP_ECODE_CANNOT_INVALIDATE, 0);1236 1237				wc_status = SIW_WC_REM_INV_REQ_ERR;1238			}1239			rv = siw_rqe_complete(qp, &wqe->rqe, wqe->processed,1240					      rv ? 0 : srx->inval_stag,1241					      wc_status);1242		} else {1243			rv = siw_rqe_complete(qp, &wqe->rqe, wqe->processed,1244					      0, wc_status);1245		}1246		siw_wqe_put_mem(wqe, SIW_OP_RECEIVE);1247		break;1248 1249	case RDMAP_RDMA_READ_RESP:1250		if (wqe->wr_status == SIW_WR_IDLE)1251			break;1252 1253		if (error != 0) {1254			if ((srx->state == SIW_GET_HDR &&1255			     qp->rx_fpdu->first_ddp_seg) || error == -ENODATA)1256				/* possible RREQ in ORQ left untouched */1257				break;1258 1259			if (wc_status == SIW_WC_SUCCESS)1260				wc_status = SIW_WC_GENERAL_ERR;1261		} else if (rdma_is_kernel_res(&qp->base_qp.res) &&1262			   rx_type(wqe) == SIW_OP_READ_LOCAL_INV) {1263			/*1264			 * Handle any STag invalidation request1265			 */1266			rv = siw_invalidate_stag(qp->pd, wqe->sqe.sge[0].lkey);1267			if (rv) {1268				siw_init_terminate(qp, TERM_ERROR_LAYER_RDMAP,1269						   RDMAP_ETYPE_CATASTROPHIC,1270						   RDMAP_ECODE_UNSPECIFIED, 0);1271 1272				if (wc_status == SIW_WC_SUCCESS) {1273					wc_status = SIW_WC_GENERAL_ERR;1274					error = rv;1275				}1276			}1277		}1278		/*1279		 * All errors turn the wqe into signalled.1280		 */1281		if ((wqe->sqe.flags & SIW_WQE_SIGNALLED) || error != 0)1282			rv = siw_sqe_complete(qp, &wqe->sqe, wqe->processed,1283					      wc_status);1284		siw_wqe_put_mem(wqe, SIW_OP_READ);1285 1286		if (!error) {1287			rv = siw_check_tx_fence(qp);1288		} else {1289			/* Disable current ORQ element */1290			if (qp->attrs.orq_size)1291				WRITE_ONCE(orq_get_current(qp)->flags, 0);1292		}1293		break;1294 1295	case RDMAP_RDMA_READ_REQ:1296		if (!error) {1297			rv = siw_init_rresp(qp, srx);1298			srx->ddp_msn[RDMAP_UNTAGGED_QN_RDMA_READ]++;1299		}1300		break;1301 1302	case RDMAP_RDMA_WRITE:1303		if (wqe->wr_status == SIW_WR_IDLE)1304			break;1305 1306		/*1307		 * Free References from memory object if1308		 * attached to receive context (inbound WRITE).1309		 * While a zero-length WRITE is allowed,1310		 * no memory reference got created.1311		 */1312		if (rx_mem(&qp->rx_tagged)) {1313			siw_mem_put(rx_mem(&qp->rx_tagged));1314			rx_mem(&qp->rx_tagged) = NULL;1315		}1316		break;1317 1318	default:1319		break;1320	}1321	wqe->wr_status = SIW_WR_IDLE;1322 1323	return rv;1324}1325 1326/*1327 * siw_tcp_rx_data()1328 *1329 * Main routine to consume inbound TCP payload1330 *1331 * @rd_desc:	read descriptor1332 * @skb:	socket buffer1333 * @off:	offset in skb1334 * @len:	skb->len - offset : payload in skb1335 */1336int siw_tcp_rx_data(read_descriptor_t *rd_desc, struct sk_buff *skb,1337		    unsigned int off, size_t len)1338{1339	struct siw_qp *qp = rd_desc->arg.data;1340	struct siw_rx_stream *srx = &qp->rx_stream;1341	int rv;1342 1343	srx->skb = skb;1344	srx->skb_new = skb->len - off;1345	srx->skb_offset = off;1346	srx->skb_copied = 0;1347 1348	siw_dbg_qp(qp, "new data, len %d\n", srx->skb_new);1349 1350	while (srx->skb_new) {1351		int run_completion = 1;1352 1353		if (unlikely(srx->rx_suspend)) {1354			/* Do not process any more data */1355			srx->skb_copied += srx->skb_new;1356			break;1357		}1358		switch (srx->state) {1359		case SIW_GET_HDR:1360			rv = siw_get_hdr(srx);1361			if (!rv) {1362				srx->fpdu_part_rem =1363					be16_to_cpu(srx->hdr.ctrl.mpa_len) -1364					srx->fpdu_part_rcvd + MPA_HDR_SIZE;1365 1366				if (srx->fpdu_part_rem)1367					srx->pad = -srx->fpdu_part_rem & 0x3;1368				else1369					srx->pad = 0;1370 1371				srx->state = SIW_GET_DATA_START;1372				srx->fpdu_part_rcvd = 0;1373			}1374			break;1375 1376		case SIW_GET_DATA_MORE:1377			/*1378			 * Another data fragment of the same DDP segment.1379			 * Setting first_ddp_seg = 0 avoids repeating1380			 * initializations that shall occur only once per1381			 * DDP segment.1382			 */1383			qp->rx_fpdu->first_ddp_seg = 0;1384			fallthrough;1385 1386		case SIW_GET_DATA_START:1387			/*1388			 * Headers will be checked by the opcode-specific1389			 * data receive function below.1390			 */1391			rv = iwarp_pktinfo[qp->rx_stream.rdmap_op].rx_data(qp);1392			if (!rv) {1393				int mpa_len =1394					be16_to_cpu(srx->hdr.ctrl.mpa_len)1395					+ MPA_HDR_SIZE;1396 1397				srx->fpdu_part_rem = (-mpa_len & 0x3)1398						      + MPA_CRC_SIZE;1399				srx->fpdu_part_rcvd = 0;1400				srx->state = SIW_GET_TRAILER;1401			} else {1402				if (unlikely(rv == -ECONNRESET))1403					run_completion = 0;1404				else1405					srx->state = SIW_GET_DATA_MORE;1406			}1407			break;1408 1409		case SIW_GET_TRAILER:1410			/*1411			 * read CRC + any padding1412			 */1413			rv = siw_get_trailer(qp, srx);1414			if (likely(!rv)) {1415				/*1416				 * FPDU completed.1417				 * complete RDMAP message if last fragment1418				 */1419				srx->state = SIW_GET_HDR;1420				srx->fpdu_part_rcvd = 0;1421 1422				if (!(srx->hdr.ctrl.ddp_rdmap_ctrl &1423				      DDP_FLAG_LAST))1424					/* more frags */1425					break;1426 1427				rv = siw_rdmap_complete(qp, 0);1428				run_completion = 0;1429			}1430			break;1431 1432		default:1433			pr_warn("QP[%u]: RX out of state\n", qp_id(qp));1434			rv = -EPROTO;1435			run_completion = 0;1436		}1437		if (unlikely(rv != 0 && rv != -EAGAIN)) {1438			if ((srx->state > SIW_GET_HDR ||1439			     qp->rx_fpdu->more_ddp_segs) && run_completion)1440				siw_rdmap_complete(qp, rv);1441 1442			siw_dbg_qp(qp, "rx error %d, rx state %d\n", rv,1443				   srx->state);1444 1445			siw_qp_cm_drop(qp, 1);1446 1447			break;1448		}1449		if (rv) {1450			siw_dbg_qp(qp, "fpdu fragment, state %d, missing %d\n",1451				   srx->state, srx->fpdu_part_rem);1452			break;1453		}1454	}1455	return srx->skb_copied;1456}1457