diff options
Diffstat (limited to 'drivers/misc/mic/scif/scif_nodeqp.c')
| -rw-r--r-- | drivers/misc/mic/scif/scif_nodeqp.c | 1312 |
1 files changed, 1312 insertions, 0 deletions
diff --git a/drivers/misc/mic/scif/scif_nodeqp.c b/drivers/misc/mic/scif/scif_nodeqp.c new file mode 100644 index 000000000000..41e3bdb10061 --- /dev/null +++ b/drivers/misc/mic/scif/scif_nodeqp.c @@ -0,0 +1,1312 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * Copyright(c) 2014 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Intel SCIF driver. + * + */ +#include "../bus/scif_bus.h" +#include "scif_peer_bus.h" +#include "scif_main.h" +#include "scif_nodeqp.h" +#include "scif_map.h" + +/* + ************************************************************************ + * SCIF node Queue Pair (QP) setup flow: + * + * 1) SCIF driver gets probed with a scif_hw_dev via the scif_hw_bus + * 2) scif_setup_qp(..) allocates the local qp and calls + * scif_setup_qp_connect(..) which allocates and maps the local + * buffer for the inbound QP + * 3) The local node updates the device page with the DMA address of the QP + * 4) A delayed work is scheduled (qp_dwork) which periodically reads if + * the peer node has updated its QP DMA address + * 5) Once a valid non zero address is found in the QP DMA address field + * in the device page, the local node maps the remote node's QP, + * updates its outbound QP and sends a SCIF_INIT message to the peer + * 6) The SCIF_INIT message is received by the peer node QP interrupt bottom + * half handler by calling scif_init(..) + * 7) scif_init(..) registers a new SCIF peer node by calling + * scif_peer_register_device(..) which signifies the addition of a new + * SCIF node + * 8) On the mgmt node, P2P network setup/teardown is initiated if all the + * remote nodes are online via scif_p2p_setup(..) + * 9) For P2P setup, the host maps the remote nodes' aperture and memory + * bars and sends a SCIF_NODE_ADD message to both nodes + * 10) As part of scif_nodeadd, both nodes set up their local inbound + * QPs and send a SCIF_NODE_ADD_ACK to the mgmt node + * 11) As part of scif_node_add_ack(..) the mgmt node forwards the + * SCIF_NODE_ADD_ACK to the remote nodes + * 12) As part of scif_node_add_ack(..) the remote nodes update their + * outbound QPs, make sure they can access memory on the remote node + * and then add a new SCIF peer node by calling + * scif_peer_register_device(..) which signifies the addition of a new + * SCIF node. + * 13) The SCIF network is now established across all nodes. + * + ************************************************************************ + * SCIF node QP teardown flow (initiated by non mgmt node): + * + * 1) SCIF driver gets a remove callback with a scif_hw_dev via the scif_hw_bus + * 2) The device page QP DMA address field is updated with 0x0 + * 3) A non mgmt node now cleans up all local data structures and sends a + * SCIF_EXIT message to the peer and waits for a SCIF_EXIT_ACK + * 4) As part of scif_exit(..) handling scif_disconnect_node(..) is called + * 5) scif_disconnect_node(..) sends a SCIF_NODE_REMOVE message to all the + * peers and waits for a SCIF_NODE_REMOVE_ACK + * 6) As part of scif_node_remove(..) a remote node unregisters the peer + * node from the SCIF network and sends a SCIF_NODE_REMOVE_ACK + * 7) When the mgmt node has received all the SCIF_NODE_REMOVE_ACKs + * it sends itself a node remove message whose handling cleans up local + * data structures and unregisters the peer node from the SCIF network + * 8) The mgmt node sends a SCIF_EXIT_ACK + * 9) Upon receipt of the SCIF_EXIT_ACK the node initiating the teardown + * completes the SCIF remove routine + * 10) The SCIF network is now torn down for the node initiating the + * teardown sequence + * + ************************************************************************ + * SCIF node QP teardown flow (initiated by mgmt node): + * + * 1) SCIF driver gets a remove callback with a scif_hw_dev via the scif_hw_bus + * 2) The device page QP DMA address field is updated with 0x0 + * 3) The mgmt node calls scif_disconnect_node(..) + * 4) scif_disconnect_node(..) sends a SCIF_NODE_REMOVE message to all the peers + * and waits for a SCIF_NODE_REMOVE_ACK + * 5) As part of scif_node_remove(..) a remote node unregisters the peer + * node from the SCIF network and sends a SCIF_NODE_REMOVE_ACK + * 6) When the mgmt node has received all the SCIF_NODE_REMOVE_ACKs + * it unregisters the peer node from the SCIF network + * 7) The mgmt node sends a SCIF_EXIT message and waits for a SCIF_EXIT_ACK. + * 8) A non mgmt node upon receipt of a SCIF_EXIT message calls scif_stop(..) + * which would clean up local data structures for all SCIF nodes and + * then send a SCIF_EXIT_ACK back to the mgmt node + * 9) Upon receipt of the SCIF_EXIT_ACK the the mgmt node sends itself a node + * remove message whose handling cleans up local data structures and + * destroys any P2P mappings. + * 10) The SCIF hardware device for which a remove callback was received is now + * disconnected from the SCIF network. + */ +/* + * Initializes "local" data structures for the QP. Allocates the QP + * ring buffer (rb) and initializes the "in bound" queue. + */ +int scif_setup_qp_connect(struct scif_qp *qp, dma_addr_t *qp_offset, + int local_size, struct scif_dev *scifdev) +{ + void *local_q = NULL; + int err = 0; + u32 tmp_rd = 0; + + spin_lock_init(&qp->send_lock); + spin_lock_init(&qp->recv_lock); + + local_q = kzalloc(local_size, GFP_KERNEL); + if (!local_q) { + err = -ENOMEM; + return err; + } + err = scif_map_single(&qp->local_buf, local_q, scifdev, local_size); + if (err) + goto kfree; + /* + * To setup the inbound_q, the buffer lives locally, the read pointer + * is remote and the write pointer is local. + */ + scif_rb_init(&qp->inbound_q, + &tmp_rd, + &qp->local_write, + local_q, get_count_order(local_size)); + /* + * The read pointer is NULL initially and it is unsafe to use the ring + * buffer til this changes! + */ + qp->inbound_q.read_ptr = NULL; + err = scif_map_single(qp_offset, qp, + scifdev, sizeof(struct scif_qp)); + if (err) + goto unmap; + qp->local_qp = *qp_offset; + return err; +unmap: + scif_unmap_single(qp->local_buf, scifdev, local_size); + qp->local_buf = 0; +kfree: + kfree(local_q); + return err; +} + +/* When the other side has already done it's allocation, this is called */ +int scif_setup_qp_accept(struct scif_qp *qp, dma_addr_t *qp_offset, + dma_addr_t phys, int local_size, + struct scif_dev *scifdev) +{ + void *local_q; + void *remote_q; + struct scif_qp *remote_qp; + int remote_size; + int err = 0; + + spin_lock_init(&qp->send_lock); + spin_lock_init(&qp->recv_lock); + /* Start by figuring out where we need to point */ + remote_qp = scif_ioremap(phys, sizeof(struct scif_qp), scifdev); + if (!remote_qp) + return -EIO; + qp->remote_qp = remote_qp; + if (qp->remote_qp->magic != SCIFEP_MAGIC) { + err = -EIO; + goto iounmap; + } + qp->remote_buf = remote_qp->local_buf; + remote_size = qp->remote_qp->inbound_q.size; + remote_q = scif_ioremap(qp->remote_buf, remote_size, scifdev); + if (!remote_q) { + err = -EIO; + goto iounmap; + } + qp->remote_qp->local_write = 0; + /* + * To setup the outbound_q, the buffer lives in remote memory, + * the read pointer is local, the write pointer is remote + */ + scif_rb_init(&qp->outbound_q, + &qp->local_read, + &qp->remote_qp->local_write, + remote_q, + get_count_order(remote_size)); + local_q = kzalloc(local_size, GFP_KERNEL); + if (!local_q) { + err = -ENOMEM; + goto iounmap_1; + } + err = scif_map_single(&qp->local_buf, local_q, scifdev, local_size); + if (err) + goto kfree; + qp->remote_qp->local_read = 0; + /* + * To setup the inbound_q, the buffer lives locally, the read pointer + * is remote and the write pointer is local + */ + scif_rb_init(&qp->inbound_q, + &qp->remote_qp->local_read, + &qp->local_write, + local_q, get_count_order(local_size)); + err = scif_map_single(qp_offset, qp, scifdev, + sizeof(struct scif_qp)); + if (err) + goto unmap; + qp->local_qp = *qp_offset; + return err; +unmap: + scif_unmap_single(qp->local_buf, scifdev, local_size); + qp->local_buf = 0; +kfree: + kfree(local_q); +iounmap_1: + scif_iounmap(remote_q, remote_size, scifdev); + qp->outbound_q.rb_base = NULL; +iounmap: + scif_iounmap(qp->remote_qp, sizeof(struct scif_qp), scifdev); + qp->remote_qp = NULL; + return err; +} + +int scif_setup_qp_connect_response(struct scif_dev *scifdev, + struct scif_qp *qp, u64 payload) +{ + int err = 0; + void *r_buf; + int remote_size; + phys_addr_t tmp_phys; + + qp->remote_qp = scif_ioremap(payload, sizeof(struct scif_qp), scifdev); + + if (!qp->remote_qp) { + err = -ENOMEM; + goto error; + } + + if (qp->remote_qp->magic != SCIFEP_MAGIC) { + dev_err(&scifdev->sdev->dev, + "SCIFEP_MAGIC mismatch between self %d remote %d\n", + scif_dev[scif_info.nodeid].node, scifdev->node); + err = -ENODEV; + goto error; + } + + tmp_phys = qp->remote_qp->local_buf; + remote_size = qp->remote_qp->inbound_q.size; + r_buf = scif_ioremap(tmp_phys, remote_size, scifdev); + + if (!r_buf) + return -EIO; + + qp->local_read = 0; + scif_rb_init(&qp->outbound_q, + &qp->local_read, + &qp->remote_qp->local_write, + r_buf, + get_count_order(remote_size)); + /* + * resetup the inbound_q now that we know where the + * inbound_read really is. + */ + scif_rb_init(&qp->inbound_q, + &qp->remote_qp->local_read, + &qp->local_write, + qp->inbound_q.rb_base, + get_count_order(qp->inbound_q.size)); +error: + return err; +} + +static __always_inline void +scif_send_msg_intr(struct scif_dev *scifdev) +{ + struct scif_hw_dev *sdev = scifdev->sdev; + + if (scifdev_is_p2p(scifdev)) + sdev->hw_ops->send_p2p_intr(sdev, scifdev->rdb, &scifdev->mmio); + else + sdev->hw_ops->send_intr(sdev, scifdev->rdb); +} + +int scif_qp_response(phys_addr_t phys, struct scif_dev *scifdev) +{ + int err = 0; + struct scifmsg msg; + + err = scif_setup_qp_connect_response(scifdev, scifdev->qpairs, phys); + if (!err) { + /* + * Now that everything is setup and mapped, we're ready + * to tell the peer about our queue's location + */ + msg.uop = SCIF_INIT; + msg.dst.node = scifdev->node; + err = scif_nodeqp_send(scifdev, &msg); + } + return err; +} + +void scif_send_exit(struct scif_dev *scifdev) +{ + struct scifmsg msg; + int ret; + + scifdev->exit = OP_IN_PROGRESS; + msg.uop = SCIF_EXIT; + msg.src.node = scif_info.nodeid; + msg.dst.node = scifdev->node; + ret = scif_nodeqp_send(scifdev, &msg); + if (ret) + goto done; + /* Wait for a SCIF_EXIT_ACK message */ + wait_event_timeout(scif_info.exitwq, scifdev->exit == OP_COMPLETED, + SCIF_NODE_ALIVE_TIMEOUT); +done: + scifdev->exit = OP_IDLE; +} + +int scif_setup_qp(struct scif_dev *scifdev) +{ + int err = 0; + int local_size; + struct scif_qp *qp; + + local_size = SCIF_NODE_QP_SIZE; + + qp = kzalloc(sizeof(*qp), GFP_KERNEL); + if (!qp) { + err = -ENOMEM; + return err; + } + qp->magic = SCIFEP_MAGIC; + scifdev->qpairs = qp; + err = scif_setup_qp_connect(qp, &scifdev->qp_dma_addr, + local_size, scifdev); + if (err) + goto free_qp; + /* + * We're as setup as we can be. The inbound_q is setup, w/o a usable + * outbound q. When we get a message, the read_ptr will be updated, + * and we will pull the message. + */ + return err; +free_qp: + kfree(scifdev->qpairs); + scifdev->qpairs = NULL; + return err; +} + +static void scif_p2p_freesg(struct scatterlist *sg) +{ + kfree(sg); +} + +static struct scatterlist * +scif_p2p_setsg(void __iomem *va, int page_size, int page_cnt) +{ + struct scatterlist *sg; + struct page *page; + int i; + + sg = kcalloc(page_cnt, sizeof(struct scatterlist), GFP_KERNEL); + if (!sg) + return NULL; + sg_init_table(sg, page_cnt); + for (i = 0; i < page_cnt; i++) { + page = vmalloc_to_page((void __force *)va); + if (!page) + goto p2p_sg_err; + sg_set_page(&sg[i], page, page_size, 0); + va += page_size; + } + return sg; +p2p_sg_err: + kfree(sg); + return NULL; +} + +/* Init p2p mappings required to access peerdev from scifdev */ +static struct scif_p2p_info * +scif_init_p2p_info(struct scif_dev *scifdev, struct scif_dev *peerdev) +{ + struct scif_p2p_info *p2p; + int num_mmio_pages, num_aper_pages, sg_page_shift, err, num_aper_chunks; + struct scif_hw_dev *psdev = peerdev->sdev; + struct scif_hw_dev *sdev = scifdev->sdev; + + num_mmio_pages = psdev->mmio->len >> PAGE_SHIFT; + num_aper_pages = psdev->aper->len >> PAGE_SHIFT; + + p2p = kzalloc(sizeof(*p2p), GFP_KERNEL); + if (!p2p) + return NULL; + p2p->ppi_sg[SCIF_PPI_MMIO] = scif_p2p_setsg(psdev->mmio->va, + PAGE_SIZE, num_mmio_pages); + if (!p2p->ppi_sg[SCIF_PPI_MMIO]) + goto free_p2p; + p2p->sg_nentries[SCIF_PPI_MMIO] = num_mmio_pages; + sg_page_shift = get_order(min(psdev->aper->len, (u64)(1 << 30))); + num_aper_chunks = num_aper_pages >> (sg_page_shift - PAGE_SHIFT); + p2p->ppi_sg[SCIF_PPI_APER] = scif_p2p_setsg(psdev->aper->va, + 1 << sg_page_shift, + num_aper_chunks); + p2p->sg_nentries[SCIF_PPI_APER] = num_aper_chunks; + err = dma_map_sg(&sdev->dev, p2p->ppi_sg[SCIF_PPI_MMIO], + num_mmio_pages, PCI_DMA_BIDIRECTIONAL); + if (err != num_mmio_pages) + goto scif_p2p_free; + err = dma_map_sg(&sdev->dev, p2p->ppi_sg[SCIF_PPI_APER], + num_aper_chunks, PCI_DMA_BIDIRECTIONAL); + if (err != num_aper_chunks) + goto dma_unmap; + p2p->ppi_da[SCIF_PPI_MMIO] = sg_dma_address(p2p->ppi_sg[SCIF_PPI_MMIO]); + p2p->ppi_da[SCIF_PPI_APER] = sg_dma_address(p2p->ppi_sg[SCIF_PPI_APER]); + p2p->ppi_len[SCIF_PPI_MMIO] = num_mmio_pages; + p2p->ppi_len[SCIF_PPI_APER] = num_aper_pages; + p2p->ppi_peer_id = peerdev->node; + return p2p; +dma_unmap: + dma_unmap_sg(&sdev->dev, p2p->ppi_sg[SCIF_PPI_MMIO], + p2p->sg_nentries[SCIF_PPI_MMIO], DMA_BIDIRECTIONAL); +scif_p2p_free: + scif_p2p_freesg(p2p->ppi_sg[SCIF_PPI_MMIO]); + scif_p2p_freesg(p2p->ppi_sg[SCIF_PPI_APER]); +free_p2p: + kfree(p2p); + return NULL; +} + +/** + * scif_node_connect: Respond to SCIF_NODE_CONNECT interrupt message + * @dst: Destination node + * + * Connect the src and dst node by setting up the p2p connection + * between them. Management node here acts like a proxy. + */ +static void scif_node_connect(struct scif_dev *scifdev, int dst) +{ + struct scif_dev *dev_j = scifdev; + struct scif_dev *dev_i = NULL; + struct scif_p2p_info *p2p_ij = NULL; /* bus addr for j from i */ + struct scif_p2p_info *p2p_ji = NULL; /* bus addr for i from j */ + struct scif_p2p_info *p2p; + struct list_head *pos, *tmp; + struct scifmsg msg; + int err; + u64 tmppayload; + + if (dst < 1 || dst > scif_info.maxid) + return; + + dev_i = &scif_dev[dst]; + + if (!_scifdev_alive(dev_i)) + return; + /* + * If the p2p connection is already setup or in the process of setting + * up then just ignore this request. The requested node will get + * informed by SCIF_NODE_ADD_ACK or SCIF_NODE_ADD_NACK + */ + if (!list_empty(&dev_i->p2p)) { + list_for_each_safe(pos, tmp, &dev_i->p2p) { + p2p = list_entry(pos, struct scif_p2p_info, ppi_list); + if (p2p->ppi_peer_id == dev_j->node) + return; + } + } + p2p_ij = scif_init_p2p_info(dev_i, dev_j); + if (!p2p_ij) + return; + p2p_ji = scif_init_p2p_info(dev_j, dev_i); + if (!p2p_ji) + return; + list_add_tail(&p2p_ij->ppi_list, &dev_i->p2p); + list_add_tail(&p2p_ji->ppi_list, &dev_j->p2p); + + /* + * Send a SCIF_NODE_ADD to dev_i, pass it its bus address + * as seen from dev_j + */ + msg.uop = SCIF_NODE_ADD; + msg.src.node = dev_j->node; + msg.dst.node = dev_i->node; + + msg.payload[0] = p2p_ji->ppi_da[SCIF_PPI_APER]; + msg.payload[1] = p2p_ij->ppi_da[SCIF_PPI_MMIO]; + msg.payload[2] = p2p_ij->ppi_da[SCIF_PPI_APER]; + msg.payload[3] = p2p_ij->ppi_len[SCIF_PPI_APER] << PAGE_SHIFT; + + err = scif_nodeqp_send(dev_i, &msg); + if (err) { + dev_err(&scifdev->sdev->dev, + "%s %d error %d\n", __func__, __LINE__, err); + return; + } + + /* Same as above but to dev_j */ + msg.uop = SCIF_NODE_ADD; + msg.src.node = dev_i->node; + msg.dst.node = dev_j->node; + + tmppayload = msg.payload[0]; + msg.payload[0] = msg.payload[2]; + msg.payload[2] = tmppayload; + msg.payload[1] = p2p_ji->ppi_da[SCIF_PPI_MMIO]; + msg.payload[3] = p2p_ji->ppi_len[SCIF_PPI_APER] << PAGE_SHIFT; + + scif_nodeqp_send(dev_j, &msg); +} + +static void scif_p2p_setup(void) +{ + int i, j; + + if (!scif_info.p2p_enable) + return; + + for (i = 1; i <= scif_info.maxid; i++) + if (!_scifdev_alive(&scif_dev[i])) + return; + + for (i = 1; i <= scif_info.maxid; i++) { + for (j = 1; j <= scif_info.maxid; j++) { + struct scif_dev *scifdev = &scif_dev[i]; + + if (i == j) + continue; + scif_node_connect(scifdev, j); + } + } +} + +void scif_qp_response_ack(struct work_struct *work) +{ + struct scif_dev *scifdev = container_of(work, struct scif_dev, + init_msg_work); + struct scif_peer_dev *spdev; + + /* Drop the INIT message if it has already been received */ + if (_scifdev_alive(scifdev)) + return; + + spdev = scif_peer_register_device(scifdev); + if (IS_ERR(spdev)) + return; + + if (scif_is_mgmt_node()) { + mutex_lock(&scif_info.conflock); + scif_p2p_setup(); + mutex_unlock(&scif_info.conflock); + } +} + +static char *message_types[] = {"BAD", + "INIT", + "EXIT", + "SCIF_EXIT_ACK", + "SCIF_NODE_ADD", + "SCIF_NODE_ADD_ACK", + "SCIF_NODE_ADD_NACK", + "REMOVE_NODE", + "REMOVE_NODE_ACK", + "CNCT_REQ", + "CNCT_GNT", + "CNCT_GNTACK", + "CNCT_GNTNACK", + "CNCT_REJ", + "DISCNCT", + "DISCNT_ACK", + "CLIENT_SENT", + "CLIENT_RCVD", + "SCIF_GET_NODE_INFO"}; + +static void +scif_display_message(struct scif_dev *scifdev, struct scifmsg *msg, + const char *label) +{ + if (!scif_info.en_msg_log) + return; + if (msg->uop > SCIF_MAX_MSG) { + dev_err(&scifdev->sdev->dev, + "%s: unknown msg type %d\n", label, msg->uop); + return; + } + dev_info(&scifdev->sdev->dev, + "%s: msg type %s, src %d:%d, dest %d:%d payload 0x%llx:0x%llx:0x%llx:0x%llx\n", + label, message_types[msg->uop], msg->src.node, msg->src.port, + msg->dst.node, msg->dst.port, msg->payload[0], msg->payload[1], + msg->payload[2], msg->payload[3]); +} + +int _scif_nodeqp_send(struct scif_dev *scifdev, struct scifmsg *msg) +{ + struct scif_qp *qp = scifdev->qpairs; + int err = -ENOMEM, loop_cnt = 0; + + scif_display_message(scifdev, msg, "Sent"); + if (!qp) { + err = -EINVAL; + goto error; + } + spin_lock(&qp->send_lock); + + while ((err = scif_rb_write(&qp->outbound_q, + msg, sizeof(struct scifmsg)))) { + mdelay(1); +#define SCIF_NODEQP_SEND_TO_MSEC (3 * 1000) + if (loop_cnt++ > (SCIF_NODEQP_SEND_TO_MSEC)) { + err = -ENODEV; + break; + } + } + if (!err) + scif_rb_commit(&qp->outbound_q); + spin_unlock(&qp->send_lock); + if (!err) { + if (scifdev_self(scifdev)) + /* + * For loopback we need to emulate an interrupt by + * queuing work for the queue handling real node + * Qp interrupts. + */ + queue_work(scifdev->intr_wq, &scifdev->intr_bh); + else + scif_send_msg_intr(scifdev); + } +error: + if (err) + dev_dbg(&scifdev->sdev->dev, + "%s %d error %d uop %d\n", + __func__, __LINE__, err, msg->uop); + return err; +} + +/** + * scif_nodeqp_send - Send a message on the node queue pair + * @scifdev: Scif Device. + * @msg: The message to be sent. + */ +int scif_nodeqp_send(struct scif_dev *scifdev, struct scifmsg *msg) +{ + int err; + struct device *spdev = NULL; + + if (msg->uop > SCIF_EXIT_ACK) { + /* Dont send messages once the exit flow has begun */ + if (OP_IDLE != scifdev->exit) + return -ENODEV; + spdev = scif_get_peer_dev(scifdev); + if (IS_ERR(spdev)) { + err = PTR_ERR(spdev); + return err; + } + } + err = _scif_nodeqp_send(scifdev, msg); + if (msg->uop > SCIF_EXIT_ACK) + scif_put_peer_dev(spdev); + return err; +} + +/* + * scif_misc_handler: + * + * Work queue handler for servicing miscellaneous SCIF tasks. + * Examples include: + * 1) Cleanup of zombie endpoints. + */ +void scif_misc_handler(struct work_struct *work) +{ + scif_cleanup_zombie_epd(); +} + +/** + * scif_init() - Respond to SCIF_INIT interrupt message + * @scifdev: Remote SCIF device node + * @msg: Interrupt message + */ +static __always_inline void +scif_init(struct scif_dev *scifdev, struct scifmsg *msg) +{ + /* + * Allow the thread waiting for device page updates for the peer QP DMA + * address to complete initializing the inbound_q. + */ + flush_delayed_work(&scifdev->qp_dwork); + /* + * Delegate the peer device registration to a workqueue, otherwise if + * SCIF client probe (called during peer device registration) calls + * scif_connect(..), it will block the message processing thread causing + * a deadlock. + */ + schedule_work(&scifdev->init_msg_work); +} + +/** + * scif_exit() - Respond to SCIF_EXIT interrupt message + * @scifdev: Remote SCIF device node + * @msg: Interrupt message + * + * This function stops the SCIF interface for the node which sent + * the SCIF_EXIT message and starts waiting for that node to + * resetup the queue pair again. + */ +static __always_inline void +scif_exit(struct scif_dev *scifdev, struct scifmsg *unused) +{ + scifdev->exit_ack_pending = true; + if (scif_is_mgmt_node()) + scif_disconnect_node(scifdev->node, false); + else + scif_stop(scifdev); + schedule_delayed_work(&scifdev->qp_dwork, + msecs_to_jiffies(1000)); +} + +/** + * scif_exitack() - Respond to SCIF_EXIT_ACK interrupt message + * @scifdev: Remote SCIF device node + * @msg: Interrupt message + * + */ +static __always_inline void +scif_exit_ack(struct scif_dev *scifdev, struct scifmsg *unused) +{ + scifdev->exit = OP_COMPLETED; + wake_up(&scif_info.exitwq); +} + +/** + * scif_node_add() - Respond to SCIF_NODE_ADD interrupt message + * @scifdev: Remote SCIF device node + * @msg: Interrupt message + * + * When the mgmt node driver has finished initializing a MIC node queue pair it + * marks the node as online. It then looks for all currently online MIC cards + * and send a SCIF_NODE_ADD message to identify the ID of the new card for + * peer to peer initialization + * + * The local node allocates its incoming queue and sends its address in the + * SCIF_NODE_ADD_ACK message back to the mgmt node, the mgmt node "reflects" + * this message to the new node + */ +static __always_inline void +scif_node_add(struct scif_dev *scifdev, struct scifmsg *msg) +{ + struct scif_dev *newdev; + dma_addr_t qp_offset; + int qp_connect; + struct scif_hw_dev *sdev; + + dev_dbg(&scifdev->sdev->dev, + "Scifdev %d:%d received NODE_ADD msg for node %d\n", + scifdev->node, msg->dst.node, msg->src.node); + dev_dbg(&scifdev->sdev->dev, + "Remote address for this node's aperture %llx\n", + msg->payload[0]); + newdev = &scif_dev[msg->src.node]; + newdev->node = msg->src.node; + newdev->sdev = scif_dev[SCIF_MGMT_NODE].sdev; + sdev = newdev->sdev; + + if (scif_setup_intr_wq(newdev)) { + dev_err(&scifdev->sdev->dev, + "failed to setup interrupts for %d\n", msg->src.node); + goto interrupt_setup_error; + } + newdev->mmio.va = ioremap_nocache(msg->payload[1], sdev->mmio->len); + if (!newdev->mmio.va) { + dev_err(&scifdev->sdev->dev, + "failed to map mmio for %d\n", msg->src.node); + goto mmio_map_error; + } + newdev->qpairs = kzalloc(sizeof(*newdev->qpairs), GFP_KERNEL); + if (!newdev->qpairs) + goto qp_alloc_error; + /* + * Set the base address of the remote node's memory since it gets + * added to qp_offset + */ + newdev->base_addr = msg->payload[0]; + + qp_connect = scif_setup_qp_connect(newdev->qpairs, &qp_offset, + SCIF_NODE_QP_SIZE, newdev); + if (qp_connect) { + dev_err(&scifdev->sdev->dev, + "failed to setup qp_connect %d\n", qp_connect); + goto qp_connect_error; + } + + newdev->db = sdev->hw_ops->next_db(sdev); + newdev->cookie = sdev->hw_ops->request_irq(sdev, scif_intr_handler, + "SCIF_INTR", newdev, + newdev->db); + if (IS_ERR(newdev->cookie)) + goto qp_connect_error; + newdev->qpairs->magic = SCIFEP_MAGIC; + newdev->qpairs->qp_state = SCIF_QP_OFFLINE; + + msg->uop = SCIF_NODE_ADD_ACK; + msg->dst.node = msg->src.node; + msg->src.node = scif_info.nodeid; + msg->payload[0] = qp_offset; + msg->payload[2] = newdev->db; + scif_nodeqp_send(&scif_dev[SCIF_MGMT_NODE], msg); + return; +qp_connect_error: + kfree(newdev->qpairs); + newdev->qpairs = NULL; +qp_alloc_error: + iounmap(newdev->mmio.va); + newdev->mmio.va = NULL; +mmio_map_error: +interrupt_setup_error: + dev_err(&scifdev->sdev->dev, + "node add failed for node %d\n", msg->src.node); + msg->uop = SCIF_NODE_ADD_NACK; + msg->dst.node = msg->src.node; + msg->src.node = scif_info.nodeid; + scif_nodeqp_send(&scif_dev[SCIF_MGMT_NODE], msg); +} + +void scif_poll_qp_state(struct work_struct *work) +{ +#define SCIF_NODE_QP_RETRY 100 +#define SCIF_NODE_QP_TIMEOUT 100 + struct scif_dev *peerdev = container_of(work, struct scif_dev, + p2p_dwork.work); + struct scif_qp *qp = &peerdev->qpairs[0]; + + if (qp->qp_state != SCIF_QP_ONLINE || + qp->remote_qp->qp_state != SCIF_QP_ONLINE) { + if (peerdev->p2p_retry++ == SCIF_NODE_QP_RETRY) { + dev_err(&peerdev->sdev->dev, + "Warning: QP check timeout with state %d\n", + qp->qp_state); + goto timeout; + } + schedule_delayed_work(&peerdev->p2p_dwork, + msecs_to_jiffies(SCIF_NODE_QP_TIMEOUT)); + return; + } + scif_peer_register_device(peerdev); + return; +timeout: + dev_err(&peerdev->sdev->dev, + "%s %d remote node %d offline, state = 0x%x\n", + __func__, __LINE__, peerdev->node, qp->qp_state); + qp->remote_qp->qp_state = SCIF_QP_OFFLINE; + scif_cleanup_scifdev(peerdev); +} + +/** + * scif_node_add_ack() - Respond to SCIF_NODE_ADD_ACK interrupt message + * @scifdev: Remote SCIF device node + * @msg: Interrupt message + * + * After a MIC node receives the SCIF_NODE_ADD_ACK message it send this + * message to the mgmt node to confirm the sequence is finished. + * + */ +static __always_inline void +scif_node_add_ack(struct scif_dev *scifdev, struct scifmsg *msg) +{ + struct scif_dev *peerdev; + struct scif_qp *qp; + struct scif_dev *dst_dev = &scif_dev[msg->dst.node]; + + dev_dbg(&scifdev->sdev->dev, + "Scifdev %d received SCIF_NODE_ADD_ACK msg src %d dst %d\n", + scifdev->node, msg->src.node, msg->dst.node); + dev_dbg(&scifdev->sdev->dev, + "payload %llx %llx %llx %llx\n", msg->payload[0], + msg->payload[1], msg->payload[2], msg->payload[3]); + if (scif_is_mgmt_node()) { + /* + * the lock serializes with scif_qp_response_ack. The mgmt node + * is forwarding the NODE_ADD_ACK message from src to dst we + * need to make sure that the dst has already received a + * NODE_ADD for src and setup its end of the qp to dst + */ + mutex_lock(&scif_info.conflock); + msg->payload[1] = scif_info.maxid; + scif_nodeqp_send(dst_dev, msg); + mutex_unlock(&scif_info.conflock); + return; + } + peerdev = &scif_dev[msg->src.node]; + peerdev->sdev = scif_dev[SCIF_MGMT_NODE].sdev; + peerdev->node = msg->src.node; + + qp = &peerdev->qpairs[0]; + + if ((scif_setup_qp_connect_response(peerdev, &peerdev->qpairs[0], + msg->payload[0]))) + goto local_error; + peerdev->rdb = msg->payload[2]; + qp->remote_qp->qp_state = SCIF_QP_ONLINE; + schedule_delayed_work(&peerdev->p2p_dwork, 0); + return; +local_error: + scif_cleanup_scifdev(peerdev); +} + +/** + * scif_node_add_nack: Respond to SCIF_NODE_ADD_NACK interrupt message + * @msg: Interrupt message + * + * SCIF_NODE_ADD failed, so inform the waiting wq. + */ +static __always_inline void +scif_node_add_nack(struct scif_dev *scifdev, struct scifmsg *msg) +{ + if (scif_is_mgmt_node()) { + struct scif_dev *dst_dev = &scif_dev[msg->dst.node]; + + dev_dbg(&scifdev->sdev->dev, + "SCIF_NODE_ADD_NACK received from %d\n", scifdev->node); + scif_nodeqp_send(dst_dev, msg); + } +} + +/* + * scif_node_remove: Handle SCIF_NODE_REMOVE message + * @msg: Interrupt message + * + * Handle node removal. + */ +static __always_inline void +scif_node_remove(struct scif_dev *scifdev, struct scifmsg *msg) +{ + int node = msg->payload[0]; + struct scif_dev *scdev = &scif_dev[node]; + + scdev->node_remove_ack_pending = true; + scif_handle_remove_node(node); +} + +/* + * scif_node_remove_ack: Handle SCIF_NODE_REMOVE_ACK message + * @msg: Interrupt message + * + * The peer has acked a SCIF_NODE_REMOVE message. + */ +static __always_inline void +scif_node_remove_ack(struct scif_dev *scifdev, struct scifmsg *msg) +{ + struct scif_dev *sdev = &scif_dev[msg->payload[0]]; + + atomic_inc(&sdev->disconn_rescnt); + wake_up(&sdev->disconn_wq); +} + +/** + * scif_get_node_info: Respond to SCIF_GET_NODE_INFO interrupt message + * @msg: Interrupt message + * + * Retrieve node info i.e maxid and total from the mgmt node. + */ +static __always_inline void +scif_get_node_info_resp(struct scif_dev *scifdev, struct scifmsg *msg) +{ + if (scif_is_mgmt_node()) { + swap(msg->dst.node, msg->src.node); + mutex_lock(&scif_info.conflock); + msg->payload[1] = scif_info.maxid; + msg->payload[2] = scif_info.total; + mutex_unlock(&scif_info.conflock); + scif_nodeqp_send(scifdev, msg); + } else { + struct completion *node_info = + (struct completion *)msg->payload[3]; + + mutex_lock(&scif_info.conflock); + scif_info.maxid = msg->payload[1]; + scif_info.total = msg->payload[2]; + complete_all(node_info); + mutex_unlock(&scif_info.conflock); + } +} + +static void +scif_msg_unknown(struct scif_dev *scifdev, struct scifmsg *msg) +{ + /* Bogus Node Qp Message? */ + dev_err(&scifdev->sdev->dev, + "Unknown message 0x%xn scifdev->node 0x%x\n", + msg->uop, scifdev->node); +} + +static void (*scif_intr_func[SCIF_MAX_MSG + 1]) + (struct scif_dev *, struct scifmsg *msg) = { + scif_msg_unknown, /* Error */ + scif_init, /* SCIF_INIT */ + scif_exit, /* SCIF_EXIT */ + scif_exit_ack, /* SCIF_EXIT_ACK */ + scif_node_add, /* SCIF_NODE_ADD */ + scif_node_add_ack, /* SCIF_NODE_ADD_ACK */ + scif_node_add_nack, /* SCIF_NODE_ADD_NACK */ + scif_node_remove, /* SCIF_NODE_REMOVE */ + scif_node_remove_ack, /* SCIF_NODE_REMOVE_ACK */ + scif_cnctreq, /* SCIF_CNCT_REQ */ + scif_cnctgnt, /* SCIF_CNCT_GNT */ + scif_cnctgnt_ack, /* SCIF_CNCT_GNTACK */ + scif_cnctgnt_nack, /* SCIF_CNCT_GNTNACK */ + scif_cnctrej, /* SCIF_CNCT_REJ */ + scif_discnct, /* SCIF_DISCNCT */ + scif_discnt_ack, /* SCIF_DISCNT_ACK */ + scif_clientsend, /* SCIF_CLIENT_SENT */ + scif_clientrcvd, /* SCIF_CLIENT_RCVD */ + scif_get_node_info_resp,/* SCIF_GET_NODE_INFO */ +}; + +/** + * scif_nodeqp_msg_handler() - Common handler for node messages + * @scifdev: Remote device to respond to + * @qp: Remote memory pointer + * @msg: The message to be handled. + * + * This routine calls the appropriate routine to handle a Node Qp + * message receipt + */ +static int scif_max_msg_id = SCIF_MAX_MSG; + +static void +scif_nodeqp_msg_handler(struct scif_dev *scifdev, + struct scif_qp *qp, struct scifmsg *msg) +{ + scif_display_message(scifdev, msg, "Rcvd"); + + if (msg->uop > (u32)scif_max_msg_id) { + /* Bogus Node Qp Message? */ + dev_err(&scifdev->sdev->dev, + "Unknown message 0x%xn scifdev->node 0x%x\n", + msg->uop, scifdev->node); + return; + } + + scif_intr_func[msg->uop](scifdev, msg); +} + +/** + * scif_nodeqp_intrhandler() - Interrupt handler for node messages + * @scifdev: Remote device to respond to + * @qp: Remote memory pointer + * + * This routine is triggered by the interrupt mechanism. It reads + * messages from the node queue RB and calls the Node QP Message handling + * routine. + */ +void scif_nodeqp_intrhandler(struct scif_dev *scifdev, struct scif_qp *qp) +{ + struct scifmsg msg; + int read_size; + + do { + read_size = scif_rb_get_next(&qp->inbound_q, &msg, sizeof(msg)); + if (!read_size) + break; + scif_nodeqp_msg_handler(scifdev, qp, &msg); + /* + * The node queue pair is unmapped so skip the read pointer + * update after receipt of a SCIF_EXIT_ACK + */ + if (SCIF_EXIT_ACK == msg.uop) + break; + scif_rb_update_read_ptr(&qp->inbound_q); + } while (1); +} + +/** + * scif_loopb_wq_handler - Loopback Workqueue Handler. + * @work: loop back work + * + * This work queue routine is invoked by the loopback work queue handler. + * It grabs the recv lock, dequeues any available messages from the head + * of the loopback message list, calls the node QP message handler, + * waits for it to return, then frees up this message and dequeues more + * elements of the list if available. + */ +static void scif_loopb_wq_handler(struct work_struct *unused) +{ + struct scif_dev *scifdev = scif_info.loopb_dev; + struct scif_qp *qp = scifdev->qpairs; + struct scif_loopb_msg *msg; + + do { + msg = NULL; + spin_lock(&qp->recv_lock); + if (!list_empty(&scif_info.loopb_recv_q)) { + msg = list_first_entry(&scif_info.loopb_recv_q, + struct scif_loopb_msg, + list); + list_del(&msg->list); + } + spin_unlock(&qp->recv_lock); + + if (msg) { + scif_nodeqp_msg_handler(scifdev, qp, &msg->msg); + kfree(msg); + } + } while (msg); +} + +/** + * scif_loopb_msg_handler() - Workqueue handler for loopback messages. + * @scifdev: SCIF device + * @qp: Queue pair. + * + * This work queue routine is triggered when a loopback message is received. + * + * We need special handling for receiving Node Qp messages on a loopback SCIF + * device via two workqueues for receiving messages. + * + * The reason we need the extra workqueue which is not required with *normal* + * non-loopback SCIF devices is the potential classic deadlock described below: + * + * Thread A tries to send a message on a loopback SCIF device and blocks since + * there is no space in the RB while it has the send_lock held or another + * lock called lock X for example. + * + * Thread B: The Loopback Node QP message receive workqueue receives the message + * and tries to send a message (eg an ACK) to the loopback SCIF device. It tries + * to grab the send lock again or lock X and deadlocks with Thread A. The RB + * cannot be drained any further due to this classic deadlock. + * + * In order to avoid deadlocks as mentioned above we have an extra level of + * indirection achieved by having two workqueues. + * 1) The first workqueue whose handler is scif_loopb_msg_handler reads + * messages from the Node QP RB, adds them to a list and queues work for the + * second workqueue. + * + * 2) The second workqueue whose handler is scif_loopb_wq_handler dequeues + * messages from the list, handles them, frees up the memory and dequeues + * more elements from the list if possible. + */ +int +scif_loopb_msg_handler(struct scif_dev *scifdev, struct scif_qp *qp) +{ + int read_size; + struct scif_loopb_msg *msg; + + do { + msg = kmalloc(sizeof(*msg), GFP_KERNEL); + if (!msg) + return -ENOMEM; + read_size = scif_rb_get_next(&qp->inbound_q, &msg->msg, + sizeof(struct scifmsg)); + if (read_size != sizeof(struct scifmsg)) { + kfree(msg); + scif_rb_update_read_ptr(&qp->inbound_q); + break; + } + spin_lock(&qp->recv_lock); + list_add_tail(&msg->list, &scif_info.loopb_recv_q); + spin_unlock(&qp->recv_lock); + queue_work(scif_info.loopb_wq, &scif_info.loopb_work); + scif_rb_update_read_ptr(&qp->inbound_q); + } while (read_size == sizeof(struct scifmsg)); + return read_size; +} + +/** + * scif_setup_loopback_qp - One time setup work for Loopback Node Qp. + * @scifdev: SCIF device + * + * Sets up the required loopback workqueues, queue pairs and ring buffers + */ +int scif_setup_loopback_qp(struct scif_dev *scifdev) +{ + int err = 0; + void *local_q; + struct scif_qp *qp; + struct scif_peer_dev *spdev; + + err = scif_setup_intr_wq(scifdev); + if (err) + goto exit; + INIT_LIST_HEAD(&scif_info.loopb_recv_q); + snprintf(scif_info.loopb_wqname, sizeof(scif_info.loopb_wqname), + "SCIF LOOPB %d", scifdev->node); + scif_info.loopb_wq = + alloc_ordered_workqueue(scif_info.loopb_wqname, 0); + if (!scif_info.loopb_wq) { + err = -ENOMEM; + goto destroy_intr; + } + INIT_WORK(&scif_info.loopb_work, scif_loopb_wq_handler); + /* Allocate Self Qpair */ + scifdev->qpairs = kzalloc(sizeof(*scifdev->qpairs), GFP_KERNEL); + if (!scifdev->qpairs) { + err = -ENOMEM; + goto destroy_loopb_wq; + } + + qp = scifdev->qpairs; + qp->magic = SCIFEP_MAGIC; + spin_lock_init(&qp->send_lock); + spin_lock_init(&qp->recv_lock); + + local_q = kzalloc(SCIF_NODE_QP_SIZE, GFP_KERNEL); + if (!local_q) { + err = -ENOMEM; + goto free_qpairs; + } + /* + * For loopback the inbound_q and outbound_q are essentially the same + * since the Node sends a message on the loopback interface to the + * outbound_q which is then received on the inbound_q. + */ + scif_rb_init(&qp->outbound_q, + &qp->local_read, + &qp->local_write, + local_q, get_count_order(SCIF_NODE_QP_SIZE)); + + scif_rb_init(&qp->inbound_q, + &qp->local_read, + &qp->local_write, + local_q, get_count_order(SCIF_NODE_QP_SIZE)); + scif_info.nodeid = scifdev->node; + spdev = scif_peer_register_device(scifdev); + if (IS_ERR(spdev)) { + err = PTR_ERR(spdev); + goto free_local_q; + } + scif_info.loopb_dev = scifdev; + return err; +free_local_q: + kfree(local_q); +free_qpairs: + kfree(scifdev->qpairs); +destroy_loopb_wq: + destroy_workqueue(scif_info.loopb_wq); +destroy_intr: + scif_destroy_intr_wq(scifdev); +exit: + return err; +} + +/** + * scif_destroy_loopback_qp - One time uninit work for Loopback Node Qp + * @scifdev: SCIF device + * + * Destroys the workqueues and frees up the Ring Buffer and Queue Pair memory. + */ +int scif_destroy_loopback_qp(struct scif_dev *scifdev) +{ + struct scif_peer_dev *spdev; + + rcu_read_lock(); + spdev = rcu_dereference(scifdev->spdev); + rcu_read_unlock(); + if (spdev) + scif_peer_unregister_device(spdev); + destroy_workqueue(scif_info.loopb_wq); + scif_destroy_intr_wq(scifdev); + kfree(scifdev->qpairs->outbound_q.rb_base); + kfree(scifdev->qpairs); + scifdev->sdev = NULL; + scif_info.loopb_dev = NULL; + return 0; +} + +void scif_destroy_p2p(struct scif_dev *scifdev) +{ + struct scif_dev *peer_dev; + struct scif_p2p_info *p2p; + struct list_head *pos, *tmp; + int bd; + + mutex_lock(&scif_info.conflock); + /* Free P2P mappings in the given node for all its peer nodes */ + list_for_each_safe(pos, tmp, &scifdev->p2p) { + p2p = list_entry(pos, struct scif_p2p_info, ppi_list); + dma_unmap_sg(&scifdev->sdev->dev, p2p->ppi_sg[SCIF_PPI_MMIO], + p2p->sg_nentries[SCIF_PPI_MMIO], + DMA_BIDIRECTIONAL); + dma_unmap_sg(&scifdev->sdev->dev, p2p->ppi_sg[SCIF_PPI_APER], + p2p->sg_nentries[SCIF_PPI_APER], + DMA_BIDIRECTIONAL); + scif_p2p_freesg(p2p->ppi_sg[SCIF_PPI_MMIO]); + scif_p2p_freesg(p2p->ppi_sg[SCIF_PPI_APER]); + list_del(pos); + kfree(p2p); + } + + /* Free P2P mapping created in the peer nodes for the given node */ + for (bd = SCIF_MGMT_NODE + 1; bd <= scif_info.maxid; bd++) { + peer_dev = &scif_dev[bd]; + list_for_each_safe(pos, tmp, &peer_dev->p2p) { + p2p = list_entry(pos, struct scif_p2p_info, ppi_list); + if (p2p->ppi_peer_id == scifdev->node) { + dma_unmap_sg(&peer_dev->sdev->dev, + p2p->ppi_sg[SCIF_PPI_MMIO], + p2p->sg_nentries[SCIF_PPI_MMIO], + DMA_BIDIRECTIONAL); + dma_unmap_sg(&peer_dev->sdev->dev, + p2p->ppi_sg[SCIF_PPI_APER], + p2p->sg_nentries[SCIF_PPI_APER], + DMA_BIDIRECTIONAL); + scif_p2p_freesg(p2p->ppi_sg[SCIF_PPI_MMIO]); + scif_p2p_freesg(p2p->ppi_sg[SCIF_PPI_APER]); + list_del(pos); + kfree(p2p); + } + } + } + mutex_unlock(&scif_info.conflock); +} |