/* * Copyright (c) 2006 Chelsio, Inc. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU * General Public License (GPL) Version 2, available from the file * COPYING in the main directory of this source tree, or the * OpenIB.org BSD license below: * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * - Redistributions of source code must retain the above * copyright notice, this list of conditions and the following * disclaimer. * * - Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials * provided with the distribution. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ #include #include #include #include #include #include #include #include #include "cxio_resource.h" #include "cxio_hal.h" #include "cxgb3_offload.h" #include "sge_defs.h" static LIST_HEAD(rdev_list); static cxio_hal_ev_callback_func_t cxio_ev_cb = NULL; static struct cxio_rdev *cxio_hal_find_rdev_by_name(char *dev_name) { struct cxio_rdev *rdev; list_for_each_entry(rdev, &rdev_list, entry) if (!strcmp(rdev->dev_name, dev_name)) return rdev; return NULL; } static struct cxio_rdev *cxio_hal_find_rdev_by_t3cdev(struct t3cdev *tdev) { struct cxio_rdev *rdev; list_for_each_entry(rdev, &rdev_list, entry) if (rdev->t3cdev_p == tdev) return rdev; return NULL; } int cxio_hal_cq_op(struct cxio_rdev *rdev_p, struct t3_cq *cq, enum t3_cq_opcode op, u32 credit) { int ret; struct t3_cqe *cqe; u32 rptr; struct rdma_cq_op setup; setup.id = cq->cqid; setup.credits = (op == CQ_CREDIT_UPDATE) ? credit : 0; setup.op = op; ret = rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, RDMA_CQ_OP, &setup); if ((ret < 0) || (op == CQ_CREDIT_UPDATE)) return ret; /* * If the rearm returned an index other than our current index, * then there might be CQE's in flight (being DMA'd). We must wait * here for them to complete or the consumer can miss a notification. */ if (Q_PTR2IDX((cq->rptr), cq->size_log2) != ret) { int i=0; rptr = cq->rptr; /* * Keep the generation correct by bumping rptr until it * matches the index returned by the rearm - 1. */ while (Q_PTR2IDX((rptr+1), cq->size_log2) != ret) rptr++; /* * Now rptr is the index for the (last) cqe that was * in-flight at the time the HW rearmed the CQ. We * spin until that CQE is valid. */ cqe = cq->queue + Q_PTR2IDX(rptr, cq->size_log2); while (!CQ_VLD_ENTRY(rptr, cq->size_log2, cqe)) { udelay(1); if (i++ > 1000000) { BUG_ON(1); printk(KERN_ERR "%s: stalled rnic\n", rdev_p->dev_name); return -EIO; } } return 1; } return 0; } static int cxio_hal_clear_cq_ctx(struct cxio_rdev *rdev_p, u32 cqid) { struct rdma_cq_setup setup; setup.id = cqid; setup.base_addr = 0; /* NULL address */ setup.size = 0; /* disaable the CQ */ setup.credits = 0; setup.credit_thres = 0; setup.ovfl_mode = 0; return (rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, RDMA_CQ_SETUP, &setup)); } static int cxio_hal_clear_qp_ctx(struct cxio_rdev *rdev_p, u32 qpid) { u64 sge_cmd; struct t3_modify_qp_wr *wqe; struct sk_buff *skb = alloc_skb(sizeof(*wqe), GFP_KERNEL); if (!skb) { PDBG("%s alloc_skb failed\n", __FUNCTION__); return -ENOMEM; } wqe = (struct t3_modify_qp_wr *) skb_put(skb, sizeof(*wqe)); memset(wqe, 0, sizeof(*wqe)); build_fw_riwrh((struct fw_riwrh *) wqe, T3_WR_QP_MOD, 3, 0, qpid, 7); wqe->flags = cpu_to_be32(MODQP_WRITE_EC); sge_cmd = qpid << 8 | 3; wqe->sge_cmd = cpu_to_be64(sge_cmd); skb->priority = CPL_PRIORITY_CONTROL; return (cxgb3_ofld_send(rdev_p->t3cdev_p, skb)); } int cxio_create_cq(struct cxio_rdev *rdev_p, struct t3_cq *cq) { struct rdma_cq_setup setup; int size = (1UL << (cq->size_log2)) * sizeof(struct t3_cqe); cq->cqid = cxio_hal_get_cqid(rdev_p->rscp); if (!cq->cqid) return -ENOMEM; cq->sw_queue = kzalloc(size, GFP_KERNEL); if (!cq->sw_queue) return -ENOMEM; cq->queue = dma_alloc_coherent(&(rdev_p->rnic_info.pdev->dev), (1UL << (cq->size_log2)) * sizeof(struct t3_cqe), &(cq->dma_addr), GFP_KERNEL); if (!cq->queue) { kfree(cq->sw_queue); return -ENOMEM; } pci_unmap_addr_set(cq, mapping, cq->dma_addr); memset(cq->queue, 0, size); setup.id = cq->cqid; setup.base_addr = (u64) (cq->dma_addr); setup.size = 1UL << cq->size_log2; setup.credits = 65535; setup.credit_thres = 1; if (rdev_p->t3cdev_p->type == T3B) setup.ovfl_mode = 0; else setup.ovfl_mode = 1; return (rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, RDMA_CQ_SETUP, &setup)); } int cxio_resize_cq(struct cxio_rdev *rdev_p, struct t3_cq *cq) { struct rdma_cq_setup setup; setup.id = cq->cqid; setup.base_addr = (u64) (cq->dma_addr); setup.size = 1UL << cq->size_log2; setup.credits = setup.size; setup.credit_thres = setup.size; /* TBD: overflow recovery */ setup.ovfl_mode = 1; return (rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, RDMA_CQ_SETUP, &setup)); } static u32 get_qpid(struct cxio_rdev *rdev_p, struct cxio_ucontext *uctx) { struct cxio_qpid_list *entry; u32 qpid; int i; mutex_lock(&uctx->lock); if (!list_empty(&uctx->qpids)) { entry = list_entry(uctx->qpids.next, struct cxio_qpid_list, entry); list_del(&entry->entry); qpid = entry->qpid; kfree(entry); } else { qpid = cxio_hal_get_qpid(rdev_p->rscp); if (!qpid) goto out; for (i = qpid+1; i & rdev_p->qpmask; i++) { entry = kmalloc(sizeof *entry, GFP_KERNEL); if (!entry) break; entry->qpid = i; list_add_tail(&entry->entry, &uctx->qpids); } } out: mutex_unlock(&uctx->lock); PDBG("%s qpid 0x%x\n", __FUNCTION__, qpid); return qpid; } static void put_qpid(struct cxio_rdev *rdev_p, u32 qpid, struct cxio_ucontext *uctx) { struct cxio_qpid_list *entry; entry = kmalloc(sizeof *entry, GFP_KERNEL); if (!entry) return; PDBG("%s qpid 0x%x\n", __FUNCTION__, qpid); entry->qpid = qpid; mutex_lock(&uctx->lock); list_add_tail(&entry->entry, &uctx->qpids); mutex_unlock(&uctx->lock); } void cxio_release_ucontext(struct cxio_rdev *rdev_p, struct cxio_ucontext *uctx) { struct list_head *pos, *nxt; struct cxio_qpid_list *entry; mutex_lock(&uctx->lock); list_for_each_safe(pos, nxt, &uctx->qpids) { entry = list_entry(pos, struct cxio_qpid_list, entry); list_del_init(&entry->entry); if (!(entry->qpid & rdev_p->qpmask)) cxio_hal_put_qpid(rdev_p->rscp, entry->qpid); kfree(entry); } mutex_unlock(&uctx->lock); } void cxio_init_ucontext(struct cxio_rdev *rdev_p, struct cxio_ucontext *uctx) { INIT_LIST_HEAD(&uctx->qpids); mutex_init(&uctx->lock); } int cxio_create_qp(struct cxio_rdev *rdev_p, u32 kernel_domain, struct t3_wq *wq, struct cxio_ucontext *uctx) { int depth = 1UL << wq->size_log2; int rqsize = 1UL << wq->rq_size_log2; wq->qpid = get_qpid(rdev_p, uctx); if (!wq->qpid) return -ENOMEM; wq->rq = kzalloc(depth * sizeof(u64), GFP_KERNEL); if (!wq->rq) goto err1; wq->rq_addr = cxio_hal_rqtpool_alloc(rdev_p, rqsize); if (!wq->rq_addr) goto err2; wq->sq = kzalloc(depth * sizeof(struct t3_swsq), GFP_KERNEL); if (!wq->sq) goto err3; wq->queue = dma_alloc_coherent(&(rdev_p->rnic_info.pdev->dev), depth * sizeof(union t3_wr), &(wq->dma_addr), GFP_KERNEL); if (!wq->queue) goto err4; memset(wq->queue, 0, depth * sizeof(union t3_wr)); pci_unmap_addr_set(wq, mapping, wq->dma_addr); wq->doorbell = (void __iomem *)rdev_p->rnic_info.kdb_addr; if (!kernel_domain) wq->udb = (u64)rdev_p->rnic_info.udbell_physbase + (wq->qpid << rdev_p->qpshift); PDBG("%s qpid 0x%x doorbell 0x%p udb 0x%llx\n", __FUNCTION__, wq->qpid, wq->doorbell, (unsigned long long) wq->udb); return 0; err4: kfree(wq->sq); err3: cxio_hal_rqtpool_free(rdev_p, wq->rq_addr, rqsize); err2: kfree(wq->rq); err1: put_qpid(rdev_p, wq->qpid, uctx); return -ENOMEM; } int cxio_destroy_cq(struct cxio_rdev *rdev_p, struct t3_cq *cq) { int err; err = cxio_hal_clear_cq_ctx(rdev_p, cq->cqid); kfree(cq->sw_queue); dma_free_coherent(&(rdev_p->rnic_info.pdev->dev), (1UL << (cq->size_log2)) * sizeof(struct t3_cqe), cq->queue, pci_unmap_addr(cq, mapping)); cxio_hal_put_cqid(rdev_p->rscp, cq->cqid); return err; } int cxio_destroy_qp(struct cxio_rdev *rdev_p, struct t3_wq *wq, struct cxio_ucontext *uctx) { dma_free_coherent(&(rdev_p->rnic_info.pdev->dev), (1UL << (wq->size_log2)) * sizeof(union t3_wr), wq->queue, pci_unmap_addr(wq, mapping)); kfree(wq->sq); cxio_hal_rqtpool_free(rdev_p, wq->rq_addr, (1UL << wq->rq_size_log2)); kfree(wq->rq); put_qpid(rdev_p, wq->qpid, uctx); return 0; } static void insert_recv_cqe(struct t3_wq *wq, struct t3_cq *cq) { struct t3_cqe cqe; PDBG("%s wq %p cq %p sw_rptr 0x%x sw_wptr 0x%x\n", __FUNCTION__, wq, cq, cq->sw_rptr, cq->sw_wptr); memset(&cqe, 0, sizeof(cqe)); cqe.header = cpu_to_be32(V_CQE_STATUS(TPT_ERR_SWFLUSH) | V_CQE_OPCODE(T3_SEND) | V_CQE_TYPE(0) | V_CQE_SWCQE(1) | V_CQE_QPID(wq->qpid) | V_CQE_GENBIT(Q_GENBIT(cq->sw_wptr, cq->size_log2))); *(cq->sw_queue + Q_PTR2IDX(cq->sw_wptr, cq->size_log2)) = cqe; cq->sw_wptr++; } void cxio_flush_rq(struct t3_wq *wq, struct t3_cq *cq, int count) { u32 ptr; PDBG("%s wq %p cq %p\n", __FUNCTION__, wq, cq); /* flush RQ */ PDBG("%s rq_rptr %u rq_wptr %u skip count %u\n", __FUNCTION__, wq->rq_rptr, wq->rq_wptr, count); ptr = wq->rq_rptr + count; while (ptr++ != wq->rq_wptr) insert_recv_cqe(wq, cq); } static void insert_sq_cqe(struct t3_wq *wq, struct t3_cq *cq, struct t3_swsq *sqp) { struct t3_cqe cqe; PDBG("%s wq %p cq %p sw_rptr 0x%x sw_wptr 0x%x\n", __FUNCTION__, wq, cq, cq->sw_rptr, cq->sw_wptr); memset(&cqe, 0, sizeof(cqe)); cqe.header = cpu_to_be32(V_CQE_STATUS(TPT_ERR_SWFLUSH) | V_CQE_OPCODE(sqp->opcode) | V_CQE_TYPE(1) | V_CQE_SWCQE(1) | V_CQE_QPID(wq->qpid) | V_CQE_GENBIT(Q_GENBIT(cq->sw_wptr, cq->size_log2))); cqe.u.scqe.wrid_hi = sqp->sq_wptr; *(cq->sw_queue + Q_PTR2IDX(cq->sw_wptr, cq->size_log2)) = cqe; cq->sw_wptr++; } void cxio_flush_sq(struct t3_wq *wq, struct t3_cq *cq, int count) { __u32 ptr; struct t3_swsq *sqp = wq->sq + Q_PTR2IDX(wq->sq_rptr, wq->sq_size_log2); ptr = wq->sq_rptr + count; sqp += count; while (ptr != wq->sq_wptr) { insert_sq_cqe(wq, cq, sqp); sqp++; ptr++; } } /* * Move all CQEs from the HWCQ into the SWCQ. */ void cxio_flush_hw_cq(struct t3_cq *cq) { struct t3_cqe *cqe, *swcqe; PDBG("%s cq %p cqid 0x%x\n", __FUNCTION__, cq, cq->cqid); cqe = cxio_next_hw_cqe(cq); while (cqe) { PDBG("%s flushing hwcq rptr 0x%x to swcq wptr 0x%x\n", __FUNCTION__, cq->rptr, cq->sw_wptr); swcqe = cq->sw_queue + Q_PTR2IDX(cq->sw_wptr, cq->size_log2); *swcqe = *cqe; swcqe->header |= cpu_to_be32(V_CQE_SWCQE(1)); cq->sw_wptr++; cq->rptr++; cqe = cxio_next_hw_cqe(cq); } } static int cqe_completes_wr(struct t3_cqe *cqe, struct t3_wq *wq) { if (CQE_OPCODE(*cqe) == T3_TERMINATE) return 0; if ((CQE_OPCODE(*cqe) == T3_RDMA_WRITE) && RQ_TYPE(*cqe)) return 0; if ((CQE_OPCODE(*cqe) == T3_READ_RESP) && SQ_TYPE(*cqe)) return 0; if ((CQE_OPCODE(*cqe) == T3_SEND) && RQ_TYPE(*cqe) && Q_EMPTY(wq->rq_rptr, wq->rq_wptr)) return 0; return 1; } void cxio_count_scqes(struct t3_cq *cq, struct t3_wq *wq, int *count) { struct t3_cqe *cqe; u32 ptr; *count = 0; ptr = cq->sw_rptr; while (!Q_EMPTY(ptr, cq->sw_wptr)) { cqe = cq->sw_queue + (Q_PTR2IDX(ptr, cq->size_log2)); if ((SQ_TYPE(*cqe) || (CQE_OPCODE(*cqe) == T3_READ_RESP)) && (CQE_QPID(*cqe) == wq->qpid)) (*count)++; ptr++; } PDBG("%s cq %p count %d\n", __FUNCTION__, cq, *count); } void cxio_count_rcqes(struct t3_cq *cq, struct t3_wq *wq, int *count) { struct t3_cqe *cqe; u32 ptr; *count = 0; PDBG("%s count zero %d\n", __FUNCTION__, *count); ptr = cq->sw_rptr; while (!Q_EMPTY(ptr, cq->sw_wptr)) { cqe = cq->sw_queue + (Q_PTR2IDX(ptr, cq->size_log2)); if (RQ_TYPE(*cqe) && (CQE_OPCODE(*cqe) != T3_READ_RESP) && (CQE_QPID(*cqe) == wq->qpid) && cqe_completes_wr(cqe, wq)) (*count)++; ptr++; } PDBG("%s cq %p count %d\n", __FUNCTION__, cq, *count); } static int cxio_hal_init_ctrl_cq(struct cxio_rdev *rdev_p) { struct rdma_cq_setup setup; setup.id = 0; setup.base_addr = 0; /* NULL address */ setup.size = 1; /* enable the CQ */ setup.credits = 0; /* force SGE to redirect to RspQ and interrupt */ setup.credit_thres = 0; setup.ovfl_mode = 1; return (rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, RDMA_CQ_SETUP, &setup)); } static int cxio_hal_init_ctrl_qp(struct cxio_rdev *rdev_p) { int err; u64 sge_cmd, ctx0, ctx1; u64 base_addr; struct t3_modify_qp_wr *wqe; struct sk_buff *skb; skb = alloc_skb(sizeof(*wqe), GFP_KERNEL); if (!skb) { PDBG("%s alloc_skb failed\n", __FUNCTION__); return -ENOMEM; } err = cxio_hal_init_ctrl_cq(rdev_p); if (err) { PDBG("%s err %d initializing ctrl_cq\n", __FUNCTION__, err); goto err; } rdev_p->ctrl_qp.workq = dma_alloc_coherent( &(rdev_p->rnic_info.pdev->dev), (1 << T3_CTRL_QP_SIZE_LOG2) * sizeof(union t3_wr), &(rdev_p->ctrl_qp.dma_addr), GFP_KERNEL); if (!rdev_p->ctrl_qp.workq) { PDBG("%s dma_alloc_coherent failed\n", __FUNCTION__); err = -ENOMEM; goto err; } pci_unmap_addr_set(&rdev_p->ctrl_qp, mapping, rdev_p->ctrl_qp.dma_addr); rdev_p->ctrl_qp.doorbell = (void __iomem *)rdev_p->rnic_info.kdb_addr; memset(rdev_p->ctrl_qp.workq, 0, (1 << T3_CTRL_QP_SIZE_LOG2) * sizeof(union t3_wr)); mutex_init(&rdev_p->ctrl_qp.lock); init_waitqueue_head(&rdev_p->ctrl_qp.waitq); /* update HW Ctrl QP context */ base_addr = rdev_p->ctrl_qp.dma_addr; base_addr >>= 12; ctx0 = (V_EC_SIZE((1 << T3_CTRL_QP_SIZE_LOG2)) | V_EC_BASE_LO((u32) base_addr & 0xffff)); ctx0 <<= 32; ctx0 |= V_EC_CREDITS(FW_WR_NUM); base_addr >>= 16; ctx1 = (u32) base_addr; base_addr >>= 32; ctx1 |= ((u64) (V_EC_BASE_HI((u32) base_addr & 0xf) | V_EC_RESPQ(0) | V_EC_TYPE(0) | V_EC_GEN(1) | V_EC_UP_TOKEN(T3_CTL_QP_TID) | F_EC_VALID)) << 32; wqe = (struct t3_modify_qp_wr *) skb_put(skb, sizeof(*wqe)); memset(wqe, 0, sizeof(*wqe)); build_fw_riwrh((struct fw_riwrh *) wqe, T3_WR_QP_MOD, 0, 0, T3_CTL_QP_TID, 7); wqe->flags = cpu_to_be32(MODQP_WRITE_EC); sge_cmd = (3ULL << 56) | FW_RI_SGEEC_START << 8 | 3; wqe->sge_cmd = cpu_to_be64(sge_cmd); wqe->ctx1 = cpu_to_be64(ctx1); wqe->ctx0 = cpu_to_be64(ctx0); PDBG("CtrlQP dma_addr 0x%llx workq %p size %d\n", (unsigned long long) rdev_p->ctrl_qp.dma_addr, rdev_p->ctrl_qp.workq, 1 << T3_CTRL_QP_SIZE_LOG2); skb->priority = CPL_PRIORITY_CONTROL; return (cxgb3_ofld_send(rdev_p->t3cdev_p, skb)); err: kfree_skb(skb); return err; } static int cxio_hal_destroy_ctrl_qp(struct cxio_rdev *rdev_p) { dma_free_coherent(&(rdev_p->rnic_info.pdev->dev), (1UL << T3_CTRL_QP_SIZE_LOG2) * sizeof(union t3_wr), rdev_p->ctrl_qp.workq, pci_unmap_addr(&rdev_p->ctrl_qp, mapping)); return cxio_hal_clear_qp_ctx(rdev_p, T3_CTRL_QP_ID); } /* write len bytes of data into addr (32B aligned address) * If data is NULL, clear len byte of memory to zero. * caller aquires the ctrl_qp lock before the call */ static int cxio_hal_ctrl_qp_write_mem(struct cxio_rdev *rdev_p, u32 addr, u32 len, void *data, int completion) { u32 i, nr_wqe, copy_len; u8 *copy_data; u8 wr_len, utx_len; /* length in 8 byte flit */ enum t3_wr_flags flag; __be64 *wqe; u64 utx_cmd; addr &= 0x7FFFFFF; nr_wqe = len % 96 ? len / 96 + 1 : len / 96; /* 96B max per WQE */ PDBG("%s wptr 0x%x rptr 0x%x len %d, nr_wqe %d data %p addr 0x%0x\n", __FUNCTION__, rdev_p->ctrl_qp.wptr, rdev_p->ctrl_qp.rptr, len, nr_wqe, data, addr); utx_len = 3; /* in 32B unit */ for (i = 0; i < nr_wqe; i++) { if (Q_FULL(rdev_p->ctrl_qp.rptr, rdev_p->ctrl_qp.wptr, T3_CTRL_QP_SIZE_LOG2)) { PDBG("%s ctrl_qp full wtpr 0x%0x rptr 0x%0x, " "wait for more space i %d\n", __FUNCTION__, rdev_p->ctrl_qp.wptr, rdev_p->ctrl_qp.rptr, i); if (wait_event_interruptible(rdev_p->ctrl_qp.waitq, !Q_FULL(rdev_p->ctrl_qp.rptr, rdev_p->ctrl_qp.wptr, T3_CTRL_QP_SIZE_LOG2))) { PDBG("%s ctrl_qp workq interrupted\n", __FUNCTION__); return -ERESTARTSYS; } PDBG("%s ctrl_qp wakeup, continue posting work request " "i %d\n", __FUNCTION__, i); } wqe = (__be64 *)(rdev_p->ctrl_qp.workq + (rdev_p->ctrl_qp.wptr % (1 << T3_CTRL_QP_SIZE_LOG2))); flag = 0; if (i == (nr_wqe - 1)) { /* last WQE */ flag = completion ? T3_COMPLETION_FLAG : 0; if (len % 32) utx_len = len / 32 + 1; else utx_len = len / 32; } /* * Force a CQE to return the credit to the workq in case * we posted more than half the max QP size of WRs */ if ((i != 0) && (i % (((1 << T3_CTRL_QP_SIZE_LOG2)) >> 1) == 0)) { flag = T3_COMPLETION_FLAG; PDBG("%s force completion at i %d\n", __FUNCTION__, i); } /* build the utx mem command */ wqe += (sizeof(struct t3_bypass_wr) >> 3); utx_cmd = (T3_UTX_MEM_WRITE << 28) | (addr + i * 3); utx_cmd <<= 32; utx_cmd |= (utx_len << 28) | ((utx_len << 2) + 1); *wqe = cpu_to_be64(utx_cmd); wqe++; copy_data = (u8 *) data + i * 96; copy_len = len > 96 ? 96 : len; /* clear memory content if data is NULL */ if (data) memcpy(wqe, copy_data, copy_len); else memset(wqe, 0, copy_len); if (copy_len % 32) memset(((u8 *) wqe) + copy_len, 0, 32 - (copy_len % 32)); wr_len = ((sizeof(struct t3_bypass_wr)) >> 3) + 1 + (utx_len << 2); wqe = (__be64 *)(rdev_p->ctrl_qp.workq + (rdev_p->ctrl_qp.wptr % (1 << T3_CTRL_QP_SIZE_LOG2))); /* wptr in the WRID[31:0] */ ((union t3_wrid *)(wqe+1))->id0.low = rdev_p->ctrl_qp.wptr; /* * This must be the last write with a memory barrier * for the genbit */ build_fw_riwrh((struct fw_riwrh *) wqe, T3_WR_BP, flag, Q_GENBIT(rdev_p->ctrl_qp.wptr, T3_CTRL_QP_SIZE_LOG2), T3_CTRL_QP_ID, wr_len); if (flag == T3_COMPLETION_FLAG) ring_doorbell(rdev_p->ctrl_qp.doorbell, T3_CTRL_QP_ID); len -= 96; rdev_p->ctrl_qp.wptr++; } return 0; } /* IN: stag key, pdid, perm, zbva, to, len, page_size, pbl, and pbl_size * OUT: stag index, actual pbl_size, pbl_addr allocated. * TBD: shared memory region support */ static int __cxio_tpt_op(struct cxio_rdev *rdev_p, u32 reset_tpt_entry, u32 *stag, u8 stag_state, u32 pdid, enum tpt_mem_type type, enum tpt_mem_perm perm, u32 zbva, u64 to, u32 len, u8 page_size, __be64 *pbl, u32 *pbl_size, u32 *pbl_addr) { int err; struct tpt_entry tpt; u32 stag_idx; u32 wptr; int rereg = (*stag != T3_STAG_UNSET); stag_state = stag_state > 0; stag_idx = (*stag) >> 8; if ((!reset_tpt_entry) && !(*stag != T3_STAG_UNSET)) { stag_idx = cxio_hal_get_stag(rdev_p->rscp); if (!stag_idx) return -ENOMEM; *stag = (stag_idx << 8) | ((*stag) & 0xFF); } PDBG("%s stag_state 0x%0x type 0x%0x pdid 0x%0x, stag_idx 0x%x\n", __FUNCTION__, stag_state, type, pdid, stag_idx); if (reset_tpt_entry) cxio_hal_pblpool_free(rdev_p, *pbl_addr, *pbl_size << 3); else if (!rereg) { *pbl_addr = cxio_hal_pblpool_alloc(rdev_p, *pbl_size << 3); if (!*pbl_addr) { return -ENOMEM; } } mutex_lock(&rdev_p->ctrl_qp.lock); /* write PBL first if any - update pbl only if pbl list exist */ if (pbl) { PDBG("%s *pdb_addr 0x%x, pbl_base 0x%x, pbl_size %d\n", __FUNCTION__, *pbl_addr, rdev_p->rnic_info.pbl_base, *pbl_size); err = cxio_hal_ctrl_qp_write_mem(rdev_p, (*pbl_addr >> 5), (*pbl_size << 3), pbl, 0); if (err) goto ret; } /* write TPT entry */ if (reset_tpt_entry) memset(&tpt, 0, sizeof(tpt)); else { tpt.valid_stag_pdid = cpu_to_be32(F_TPT_VALID | V_TPT_STAG_KEY((*stag) & M_TPT_STAG_KEY) | V_TPT_STAG_STATE(stag_state) | V_TPT_STAG_TYPE(type) | V_TPT_PDID(pdid)); BUG_ON(page_size >= 28); tpt.flags_pagesize_qpid = cpu_to_be32(V_TPT_PERM(perm) | F_TPT_MW_BIND_ENABLE | V_TPT_ADDR_TYPE((zbva ? TPT_ZBTO : TPT_VATO)) | V_TPT_PAGE_SIZE(page_size)); tpt.rsvd_pbl_addr = reset_tpt_entry ? 0 : cpu_to_be32(V_TPT_PBL_ADDR(PBL_OFF(rdev_p, *pbl_addr)>>3)); tpt.len = cpu_to_be32(len); tpt.va_hi = cpu_to_be32((u32) (to >> 32)); tpt.va_low_or_fbo = cpu_to_be32((u32) (to & 0xFFFFFFFFULL)); tpt.rsvd_bind_cnt_or_pstag = 0; tpt.rsvd_pbl_size = reset_tpt_entry ? 0 : cpu_to_be32(V_TPT_PBL_SIZE((*pbl_size) >> 2)); } err = cxio_hal_ctrl_qp_write_mem(rdev_p, stag_idx + (rdev_p->rnic_info.tpt_base >> 5), sizeof(tpt), &tpt, 1); /* release the stag index to free pool */ if (reset_tpt_entry) cxio_hal_put_stag(rdev_p->rscp, stag_idx); ret: wptr = rdev_p->ctrl_qp.wptr; mutex_unlock(&rdev_p->ctrl_qp.lock); if (!err) if (wait_event_interruptible(rdev_p->ctrl_qp.waitq, SEQ32_GE(rdev_p->ctrl_qp.rptr, wptr))) return -ERESTARTSYS; return err; } int cxio_register_phys_mem(struct cxio_rdev *rdev_p, u32 *stag, u32 pdid, enum tpt_mem_perm perm, u32 zbva, u64 to, u32 len, u8 page_size, __be64 *pbl, u32 *pbl_size, u32 *pbl_addr) { *stag = T3_STAG_UNSET; return __cxio_tpt_op(rdev_p, 0, stag, 1, pdid, TPT_NON_SHARED_MR, perm, zbva, to, len, page_size, pbl, pbl_size, pbl_addr); } int cxio_reregister_phys_mem(struct cxio_rdev *rdev_p, u32 *stag, u32 pdid, enum tpt_mem_perm perm, u32 zbva, u64 to, u32 len, u8 page_size, __be64 *pbl, u32 *pbl_size, u32 *pbl_addr) { return __cxio_tpt_op(rdev_p, 0, stag, 1, pdid, TPT_NON_SHARED_MR, perm, zbva, to, len, page_size, pbl, pbl_size, pbl_addr); } int cxio_dereg_mem(struct cxio_rdev *rdev_p, u32 stag, u32 pbl_size, u32 pbl_addr) { return __cxio_tpt_op(rdev_p, 1, &stag, 0, 0, 0, 0, 0, 0ULL, 0, 0, NULL, &pbl_size, &pbl_addr); } int cxio_allocate_window(struct cxio_rdev *rdev_p, u32 * stag, u32 pdid) { u32 pbl_size = 0; *stag = T3_STAG_UNSET; return __cxio_tpt_op(rdev_p, 0, stag, 0, pdid, TPT_MW, 0, 0, 0ULL, 0, 0, NULL, &pbl_size, NULL); } int cxio_deallocate_window(struct cxio_rdev *rdev_p, u32 stag) { return __cxio_tpt_op(rdev_p, 1, &stag, 0, 0, 0, 0, 0, 0ULL, 0, 0, NULL, NULL, NULL); } int cxio_rdma_init(struct cxio_rdev *rdev_p, struct t3_rdma_init_attr *attr) { struct t3_rdma_init_wr *wqe; struct sk_buff *skb = alloc_skb(sizeof(*wqe), GFP_ATOMIC); if (!skb) return -ENOMEM; PDBG("%s rdev_p %p\n", __FUNCTION__, rdev_p); wqe = (struct t3_rdma_init_wr *) __skb_put(skb, sizeof(*wqe)); wqe->wrh.op_seop_flags = cpu_to_be32(V_FW_RIWR_OP(T3_WR_INIT)); wqe->wrh.gen_tid_len = cpu_to_be32(V_FW_RIWR_TID(attr->tid) | V_FW_RIWR_LEN(sizeof(*wqe) >> 3)); wqe->wrid.id1 = 0; wqe->qpid = cpu_to_be32(attr->qpid); wqe->pdid = cpu_to_be32(attr->pdid); wqe->scqid = cpu_to_be32(attr->scqid); wqe->rcqid = cpu_to_be32(attr->rcqid); wqe->rq_addr = cpu_to_be32(attr->rq_addr - rdev_p->rnic_info.rqt_base); wqe->rq_size = cpu_to_be32(attr->rq_size); wqe->mpaattrs = attr->mpaattrs; wqe->qpcaps = attr->qpcaps; wqe->ulpdu_size = cpu_to_be16(attr->tcp_emss); wqe->flags = cpu_to_be32(attr->flags); wqe->ord = cpu_to_be32(attr->ord); wqe->ird = cpu_to_be32(attr->ird); wqe->qp_dma_addr = cpu_to_be64(attr->qp_dma_addr); wqe->qp_dma_size = cpu_to_be32(attr->qp_dma_size); wqe->irs = cpu_to_be32(attr->irs); skb->priority = 0; /* 0=>ToeQ; 1=>CtrlQ */ return (cxgb3_ofld_send(rdev_p->t3cdev_p, skb)); } void cxio_register_ev_cb(cxio_hal_ev_callback_func_t ev_cb) { cxio_ev_cb = ev_cb; } void cxio_unregister_ev_cb(cxio_hal_ev_callback_func_t ev_cb) { cxio_ev_cb = NULL; } static int cxio_hal_ev_handler(struct t3cdev *t3cdev_p, struct sk_buff *skb) { static int cnt; struct cxio_rdev *rdev_p = NULL; struct respQ_msg_t *rsp_msg = (struct respQ_msg_t *) skb->data; PDBG("%d: %s cq_id 0x%x cq_ptr 0x%x genbit %0x overflow %0x an %0x" " se %0x notify %0x cqbranch %0x creditth %0x\n", cnt, __FUNCTION__, RSPQ_CQID(rsp_msg), RSPQ_CQPTR(rsp_msg), RSPQ_GENBIT(rsp_msg), RSPQ_OVERFLOW(rsp_msg), RSPQ_AN(rsp_msg), RSPQ_SE(rsp_msg), RSPQ_NOTIFY(rsp_msg), RSPQ_CQBRANCH(rsp_msg), RSPQ_CREDIT_THRESH(rsp_msg)); PDBG("CQE: QPID 0x%0x genbit %0x type 0x%0x status 0x%0x opcode %d " "len 0x%0x wrid_hi_stag 0x%x wrid_low_msn 0x%x\n", CQE_QPID(rsp_msg->cqe), CQE_GENBIT(rsp_msg->cqe), CQE_TYPE(rsp_msg->cqe), CQE_STATUS(rsp_msg->cqe), CQE_OPCODE(rsp_msg->cqe), CQE_LEN(rsp_msg->cqe), CQE_WRID_HI(rsp_msg->cqe), CQE_WRID_LOW(rsp_msg->cqe)); rdev_p = (struct cxio_rdev *)t3cdev_p->ulp; if (!rdev_p) { PDBG("%s called by t3cdev %p with null ulp\n", __FUNCTION__, t3cdev_p); return 0; } if (CQE_QPID(rsp_msg->cqe) == T3_CTRL_QP_ID) { rdev_p->ctrl_qp.rptr = CQE_WRID_LOW(rsp_msg->cqe) + 1; wake_up_interruptible(&rdev_p->ctrl_qp.waitq); dev_kfree_skb_irq(skb); } else if (CQE_QPID(rsp_msg->cqe) == 0xfff8) dev_kfree_skb_irq(skb); else if (cxio_ev_cb) (*cxio_ev_cb) (rdev_p, skb); else dev_kfree_skb_irq(skb); cnt++; return 0; } /* Caller takes care of locking if needed */ int cxio_rdev_open(struct cxio_rdev *rdev_p) { struct net_device *netdev_p = NULL; int err = 0; if (strlen(rdev_p->dev_name)) { if (cxio_hal_find_rdev_by_name(rdev_p->dev_name)) { return -EBUSY; } netdev_p = dev_get_by_name(&init_net, rdev_p->dev_name); if (!netdev_p) { return -EINVAL; } dev_put(netdev_p); } else if (rdev_p->t3cdev_p) { if (cxio_hal_find_rdev_by_t3cdev(rdev_p->t3cdev_p)) { return -EBUSY; } netdev_p = rdev_p->t3cdev_p->lldev; strncpy(rdev_p->dev_name, rdev_p->t3cdev_p->name, T3_MAX_DEV_NAME_LEN); } else { PDBG("%s t3cdev_p or dev_name must be set\n", __FUNCTION__); return -EINVAL; } list_add_tail(&rdev_p->entry, &rdev_list); PDBG("%s opening rnic dev %s\n", __FUNCTION__, rdev_p->dev_name); memset(&rdev_p->ctrl_qp, 0, sizeof(rdev_p->ctrl_qp)); if (!rdev_p->t3cdev_p) rdev_p->t3cdev_p = dev2t3cdev(netdev_p); rdev_p->t3cdev_p->ulp = (void *) rdev_p; err = rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, RDMA_GET_PARAMS, &(rdev_p->rnic_info)); if (err) { printk(KERN_ERR "%s t3cdev_p(%p)->ctl returned error %d.\n", __FUNCTION__, rdev_p->t3cdev_p, err); goto err1; } err = rdev_p->t3cdev_p->ctl(rdev_p->t3cdev_p, GET_PORTS, &(rdev_p->port_info)); if (err) { printk(KERN_ERR "%s t3cdev_p(%p)->ctl returned error %d.\n", __FUNCTION__, rdev_p->t3cdev_p, err); goto err1; } /* * qpshift is the number of bits to shift the qpid left in order * to get the correct address of the doorbell for that qp. */ cxio_init_ucontext(rdev_p, &rdev_p->uctx); rdev_p->qpshift = PAGE_SHIFT - ilog2(65536 >> ilog2(rdev_p->rnic_info.udbell_len >> PAGE_SHIFT)); rdev_p->qpnr = rdev_p->rnic_info.udbell_len >> PAGE_SHIFT; rdev_p->qpmask = (65536 >> ilog2(rdev_p->qpnr)) - 1; PDBG("%s rnic %s info: tpt_base 0x%0x tpt_top 0x%0x num stags %d " "pbl_base 0x%0x pbl_top 0x%0x rqt_base 0x%0x, rqt_top 0x%0x\n", __FUNCTION__, rdev_p->dev_name, rdev_p->rnic_info.tpt_base, rdev_p->rnic_info.tpt_top, cxio_num_stags(rdev_p), rdev_p->rnic_info.pbl_base, rdev_p->rnic_info.pbl_top, rdev_p->rnic_info.rqt_base, rdev_p->rnic_info.rqt_top); PDBG("udbell_len 0x%0x udbell_physbase 0x%lx kdb_addr %p qpshift %lu " "qpnr %d qpmask 0x%x\n", rdev_p->rnic_info.udbell_len, rdev_p->rnic_info.udbell_physbase, rdev_p->rnic_info.kdb_addr, rdev_p->qpshift, rdev_p->qpnr, rdev_p->qpmask); err = cxio_hal_init_ctrl_qp(rdev_p); if (err) { printk(KERN_ERR "%s error %d initializing ctrl_qp.\n", __FUNCTION__, err); goto err1; } err = cxio_hal_init_resource(rdev_p, cxio_num_stags(rdev_p), 0, 0, T3_MAX_NUM_QP, T3_MAX_NUM_CQ, T3_MAX_NUM_PD); if (err) { printk(KERN_ERR "%s error %d initializing hal resources.\n", __FUNCTION__, err); goto err2; } err = cxio_hal_pblpool_create(rdev_p); if (err) { printk(KERN_ERR "%s error %d initializing pbl mem pool.\n", __FUNCTION__, err); goto err3; } err = cxio_hal_rqtpool_create(rdev_p); if (err) { printk(KERN_ERR "%s error %d initializing rqt mem pool.\n", __FUNCTION__, err); goto err4; } return 0; err4: cxio_hal_pblpool_destroy(rdev_p); err3: cxio_hal_destroy_resource(rdev_p->rscp); err2: cxio_hal_destroy_ctrl_qp(rdev_p); err1: list_del(&rdev_p->entry); return err; } void cxio_rdev_close(struct cxio_rdev *rdev_p) { if (rdev_p) { cxio_hal_pblpool_destroy(rdev_p); cxio_hal_rqtpool_destroy(rdev_p); list_del(&rdev_p->entry); rdev_p->t3cdev_p->ulp = NULL; cxio_hal_destroy_ctrl_qp(rdev_p); cxio_hal_destroy_resource(rdev_p->rscp); } } int __init cxio_hal_init(void) { if (cxio_hal_init_rhdl_resource(T3_MAX_NUM_RI)) return -ENOMEM; t3_register_cpl_handler(CPL_ASYNC_NOTIF, cxio_hal_ev_handler); return 0; } void __exit cxio_hal_exit(void) { struct cxio_rdev *rdev, *tmp; t3_register_cpl_handler(CPL_ASYNC_NOTIF, NULL); list_for_each_entry_safe(rdev, tmp, &rdev_list, entry) cxio_rdev_close(rdev); cxio_hal_destroy_rhdl_resource(); } static void flush_completed_wrs(struct t3_wq *wq, struct t3_cq *cq) { struct t3_swsq *sqp; __u32 ptr = wq->sq_rptr; int count = Q_COUNT(wq->sq_rptr, wq->sq_wptr); sqp = wq->sq + Q_PTR2IDX(ptr, wq->sq_size_log2); while (count--) if (!sqp->signaled) { ptr++; sqp = wq->sq + Q_PTR2IDX(ptr, wq->sq_size_log2); } else if (sqp->complete) { /* * Insert this completed cqe into the swcq. */ PDBG("%s moving cqe into swcq sq idx %ld cq idx %ld\n", __FUNCTION__, Q_PTR2IDX(ptr, wq->sq_size_log2), Q_PTR2IDX(cq->sw_wptr, cq->size_log2)); sqp->cqe.header |= htonl(V_CQE_SWCQE(1)); *(cq->sw_queue + Q_PTR2IDX(cq->sw_wptr, cq->size_log2)) = sqp->cqe; cq->sw_wptr++; sqp->signaled = 0; break; } else break; } static void create_read_req_cqe(struct t3_wq *wq, struct t3_cqe *hw_cqe, struct t3_cqe *read_cqe) { read_cqe->u.scqe.wrid_hi = wq->oldest_read->sq_wptr; read_cqe->len = wq->oldest_read->read_len; read_cqe->header = htonl(V_CQE_QPID(CQE_QPID(*hw_cqe)) | V_CQE_SWCQE(SW_CQE(*hw_cqe)) | V_CQE_OPCODE(T3_READ_REQ) | V_CQE_TYPE(1)); } /* * Return a ptr to the next read wr in the SWSQ or NULL. */ static void advance_oldest_read(struct t3_wq *wq) { u32 rptr = wq->oldest_read - wq->sq + 1; u32 wptr = Q_PTR2IDX(wq->sq_wptr, wq->sq_size_log2); while (Q_PTR2IDX(rptr, wq->sq_size_log2) != wptr) { wq->oldest_read = wq->sq + Q_PTR2IDX(rptr, wq->sq_size_log2); if (wq->oldest_read->opcode == T3_READ_REQ) return; rptr++; } wq->oldest_read = NULL; } /* * cxio_poll_cq * * Caller must: * check the validity of the first CQE, * supply the wq assicated with the qpid. * * credit: cq credit to return to sge. * cqe_flushed: 1 iff the CQE is flushed. * cqe: copy of the polled CQE. * * return value: * 0 CQE returned, * -1 CQE skipped, try again. */ int cxio_poll_cq(struct t3_wq *wq, struct t3_cq *cq, struct t3_cqe *cqe, u8 *cqe_flushed, u64 *cookie, u32 *credit) { int ret = 0; struct t3_cqe *hw_cqe, read_cqe; *cqe_flushed = 0; *credit = 0; hw_cqe = cxio_next_cqe(cq); PDBG("%s CQE OOO %d qpid 0x%0x genbit %d type %d status 0x%0x" " opcode 0x%0x len 0x%0x wrid_hi_stag 0x%x wrid_low_msn 0x%x\n", __FUNCTION__, CQE_OOO(*hw_cqe), CQE_QPID(*hw_cqe), CQE_GENBIT(*hw_cqe), CQE_TYPE(*hw_cqe), CQE_STATUS(*hw_cqe), CQE_OPCODE(*hw_cqe), CQE_LEN(*hw_cqe), CQE_WRID_HI(*hw_cqe), CQE_WRID_LOW(*hw_cqe)); /* * skip cqe's not affiliated with a QP. */ if (wq == NULL) { ret = -1; goto skip_cqe; } /* * Gotta tweak READ completions: * 1) the cqe doesn't contain the sq_wptr from the wr. * 2) opcode not reflected from the wr. * 3) read_len not reflected from the wr. * 4) cq_type is RQ_TYPE not SQ_TYPE. */ if (RQ_TYPE(*hw_cqe) && (CQE_OPCODE(*hw_cqe) == T3_READ_RESP)) { /* * Don't write to the HWCQ, so create a new read req CQE * in local memory. */ create_read_req_cqe(wq, hw_cqe, &read_cqe); hw_cqe = &read_cqe; advance_oldest_read(wq); } /* * T3A: Discard TERMINATE CQEs. */ if (CQE_OPCODE(*hw_cqe) == T3_TERMINATE) { ret = -1; wq->error = 1; goto skip_cqe; } if (CQE_STATUS(*hw_cqe) || wq->error) { *cqe_flushed = wq->error; wq->error = 1; /* * T3A inserts errors into the CQE. We cannot return * these as work completions. */ /* incoming write failures */ if ((CQE_OPCODE(*hw_cqe) == T3_RDMA_WRITE) && RQ_TYPE(*hw_cqe)) { ret = -1; goto skip_cqe; } /* incoming read request failures */ if ((CQE_OPCODE(*hw_cqe) == T3_READ_RESP) && SQ_TYPE(*hw_cqe)) { ret = -1; goto skip_cqe; } /* incoming SEND with no receive posted failures */ if ((CQE_OPCODE(*hw_cqe) == T3_SEND) && RQ_TYPE(*hw_cqe) && Q_EMPTY(wq->rq_rptr, wq->rq_wptr)) { ret = -1; goto skip_cqe; } goto proc_cqe; } /* * RECV completion. */ if (RQ_TYPE(*hw_cqe)) { /* * HW only validates 4 bits of MSN. So we must validate that * the MSN in the SEND is the next expected MSN. If its not, * then we complete this with TPT_ERR_MSN and mark the wq in * error. */ if (unlikely((CQE_WRID_MSN(*hw_cqe) != (wq->rq_rptr + 1)))) { wq->error = 1; hw_cqe->header |= htonl(V_CQE_STATUS(TPT_ERR_MSN)); goto proc_cqe; } goto proc_cqe; } /* * If we get here its a send completion. * * Handle out of order completion. These get stuffed * in the SW SQ. Then the SW SQ is walked to move any * now in-order completions into the SW CQ. This handles * 2 cases: * 1) reaping unsignaled WRs when the first subsequent * signaled WR is completed. * 2) out of order read completions. */ if (!SW_CQE(*hw_cqe) && (CQE_WRID_SQ_WPTR(*hw_cqe) != wq->sq_rptr)) { struct t3_swsq *sqp; PDBG("%s out of order completion going in swsq at idx %ld\n", __FUNCTION__, Q_PTR2IDX(CQE_WRID_SQ_WPTR(*hw_cqe), wq->sq_size_log2)); sqp = wq->sq + Q_PTR2IDX(CQE_WRID_SQ_WPTR(*hw_cqe), wq->sq_size_log2); sqp->cqe = *hw_cqe; sqp->complete = 1; ret = -1; goto flush_wq; } proc_cqe: *cqe = *hw_cqe; /* * Reap the associated WR(s) that are freed up with this * completion. */ if (SQ_TYPE(*hw_cqe)) { wq->sq_rptr = CQE_WRID_SQ_WPTR(*hw_cqe); PDBG("%s completing sq idx %ld\n", __FUNCTION__, Q_PTR2IDX(wq->sq_rptr, wq->sq_size_log2)); *cookie = (wq->sq + Q_PTR2IDX(wq->sq_rptr, wq->sq_size_log2))->wr_id; wq->sq_rptr++; } else { PDBG("%s completing rq idx %ld\n", __FUNCTION__, Q_PTR2IDX(wq->rq_rptr, wq->rq_size_log2)); *cookie = *(wq->rq + Q_PTR2IDX(wq->rq_rptr, wq->rq_size_log2)); wq->rq_rptr++; } flush_wq: /* * Flush any completed cqes that are now in-order. */ flush_completed_wrs(wq, cq); skip_cqe: if (SW_CQE(*hw_cqe)) { PDBG("%s cq %p cqid 0x%x skip sw cqe sw_rptr 0x%x\n", __FUNCTION__, cq, cq->cqid, cq->sw_rptr); ++cq->sw_rptr; } else { PDBG("%s cq %p cqid 0x%x skip hw cqe rptr 0x%x\n", __FUNCTION__, cq, cq->cqid, cq->rptr); ++cq->rptr; /* * T3A: compute credits. */ if (((cq->rptr - cq->wptr) > (1 << (cq->size_log2 - 1))) || ((cq->rptr - cq->wptr) >= 128)) { *credit = cq->rptr - cq->wptr; cq->wptr = cq->rptr; } } return ret; }