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-rw-r--r--net/smc/smc_ism.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
new file mode 100644
index 000000000000..cfade7fdcc6d
--- /dev/null
+++ b/net/smc/smc_ism.c
@@ -0,0 +1,314 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Shared Memory Communications Direct over ISM devices (SMC-D)
+ *
+ * Functions for ISM device.
+ *
+ * Copyright IBM Corp. 2018
+ */
+
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <asm/page.h>
+
+#include "smc.h"
+#include "smc_core.h"
+#include "smc_ism.h"
+#include "smc_pnet.h"
+
+struct smcd_dev_list smcd_dev_list = {
+ .list = LIST_HEAD_INIT(smcd_dev_list.list),
+ .lock = __SPIN_LOCK_UNLOCKED(smcd_dev_list.lock)
+};
+
+/* Test if an ISM communication is possible. */
+int smc_ism_cantalk(u64 peer_gid, unsigned short vlan_id, struct smcd_dev *smcd)
+{
+ return smcd->ops->query_remote_gid(smcd, peer_gid, vlan_id ? 1 : 0,
+ vlan_id);
+}
+
+int smc_ism_write(struct smcd_dev *smcd, const struct smc_ism_position *pos,
+ void *data, size_t len)
+{
+ int rc;
+
+ rc = smcd->ops->move_data(smcd, pos->token, pos->index, pos->signal,
+ pos->offset, data, len);
+
+ return rc < 0 ? rc : 0;
+}
+
+/* Set a connection using this DMBE. */
+void smc_ism_set_conn(struct smc_connection *conn)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
+ conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = conn;
+ spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
+}
+
+/* Unset a connection using this DMBE. */
+void smc_ism_unset_conn(struct smc_connection *conn)
+{
+ unsigned long flags;
+
+ if (!conn->rmb_desc)
+ return;
+
+ spin_lock_irqsave(&conn->lgr->smcd->lock, flags);
+ conn->lgr->smcd->conn[conn->rmb_desc->sba_idx] = NULL;
+ spin_unlock_irqrestore(&conn->lgr->smcd->lock, flags);
+}
+
+/* Register a VLAN identifier with the ISM device. Use a reference count
+ * and add a VLAN identifier only when the first DMB using this VLAN is
+ * registered.
+ */
+int smc_ism_get_vlan(struct smcd_dev *smcd, unsigned short vlanid)
+{
+ struct smc_ism_vlanid *new_vlan, *vlan;
+ unsigned long flags;
+ int rc = 0;
+
+ if (!vlanid) /* No valid vlan id */
+ return -EINVAL;
+
+ /* create new vlan entry, in case we need it */
+ new_vlan = kzalloc(sizeof(*new_vlan), GFP_KERNEL);
+ if (!new_vlan)
+ return -ENOMEM;
+ new_vlan->vlanid = vlanid;
+ refcount_set(&new_vlan->refcnt, 1);
+
+ /* if there is an existing entry, increase count and return */
+ spin_lock_irqsave(&smcd->lock, flags);
+ list_for_each_entry(vlan, &smcd->vlan, list) {
+ if (vlan->vlanid == vlanid) {
+ refcount_inc(&vlan->refcnt);
+ kfree(new_vlan);
+ goto out;
+ }
+ }
+
+ /* no existing entry found.
+ * add new entry to device; might fail, e.g., if HW limit reached
+ */
+ if (smcd->ops->add_vlan_id(smcd, vlanid)) {
+ kfree(new_vlan);
+ rc = -EIO;
+ goto out;
+ }
+ list_add_tail(&new_vlan->list, &smcd->vlan);
+out:
+ spin_unlock_irqrestore(&smcd->lock, flags);
+ return rc;
+}
+
+/* Unregister a VLAN identifier with the ISM device. Use a reference count
+ * and remove a VLAN identifier only when the last DMB using this VLAN is
+ * unregistered.
+ */
+int smc_ism_put_vlan(struct smcd_dev *smcd, unsigned short vlanid)
+{
+ struct smc_ism_vlanid *vlan;
+ unsigned long flags;
+ bool found = false;
+ int rc = 0;
+
+ if (!vlanid) /* No valid vlan id */
+ return -EINVAL;
+
+ spin_lock_irqsave(&smcd->lock, flags);
+ list_for_each_entry(vlan, &smcd->vlan, list) {
+ if (vlan->vlanid == vlanid) {
+ if (!refcount_dec_and_test(&vlan->refcnt))
+ goto out;
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ rc = -ENOENT;
+ goto out; /* VLAN id not in table */
+ }
+
+ /* Found and the last reference just gone */
+ if (smcd->ops->del_vlan_id(smcd, vlanid))
+ rc = -EIO;
+ list_del(&vlan->list);
+ kfree(vlan);
+out:
+ spin_unlock_irqrestore(&smcd->lock, flags);
+ return rc;
+}
+
+int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
+{
+ struct smcd_dmb dmb;
+
+ memset(&dmb, 0, sizeof(dmb));
+ dmb.dmb_tok = dmb_desc->token;
+ dmb.sba_idx = dmb_desc->sba_idx;
+ dmb.cpu_addr = dmb_desc->cpu_addr;
+ dmb.dma_addr = dmb_desc->dma_addr;
+ dmb.dmb_len = dmb_desc->len;
+ return smcd->ops->unregister_dmb(smcd, &dmb);
+}
+
+int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
+ struct smc_buf_desc *dmb_desc)
+{
+ struct smcd_dmb dmb;
+ int rc;
+
+ memset(&dmb, 0, sizeof(dmb));
+ dmb.dmb_len = dmb_len;
+ dmb.sba_idx = dmb_desc->sba_idx;
+ dmb.vlan_id = lgr->vlan_id;
+ dmb.rgid = lgr->peer_gid;
+ rc = lgr->smcd->ops->register_dmb(lgr->smcd, &dmb);
+ if (!rc) {
+ dmb_desc->sba_idx = dmb.sba_idx;
+ dmb_desc->token = dmb.dmb_tok;
+ dmb_desc->cpu_addr = dmb.cpu_addr;
+ dmb_desc->dma_addr = dmb.dma_addr;
+ dmb_desc->len = dmb.dmb_len;
+ }
+ return rc;
+}
+
+struct smc_ism_event_work {
+ struct work_struct work;
+ struct smcd_dev *smcd;
+ struct smcd_event event;
+};
+
+/* worker for SMC-D events */
+static void smc_ism_event_work(struct work_struct *work)
+{
+ struct smc_ism_event_work *wrk =
+ container_of(work, struct smc_ism_event_work, work);
+
+ switch (wrk->event.type) {
+ case ISM_EVENT_GID: /* GID event, token is peer GID */
+ smc_smcd_terminate(wrk->smcd, wrk->event.tok);
+ break;
+ case ISM_EVENT_DMB:
+ break;
+ }
+ kfree(wrk);
+}
+
+static void smcd_release(struct device *dev)
+{
+ struct smcd_dev *smcd = container_of(dev, struct smcd_dev, dev);
+
+ kfree(smcd->conn);
+ kfree(smcd);
+}
+
+struct smcd_dev *smcd_alloc_dev(struct device *parent, const char *name,
+ const struct smcd_ops *ops, int max_dmbs)
+{
+ struct smcd_dev *smcd;
+
+ smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
+ if (!smcd)
+ return NULL;
+ smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
+ GFP_KERNEL);
+ if (!smcd->conn) {
+ kfree(smcd);
+ return NULL;
+ }
+
+ smcd->dev.parent = parent;
+ smcd->dev.release = smcd_release;
+ device_initialize(&smcd->dev);
+ dev_set_name(&smcd->dev, name);
+ smcd->ops = ops;
+ smc_pnetid_by_dev_port(parent, 0, smcd->pnetid);
+
+ spin_lock_init(&smcd->lock);
+ INIT_LIST_HEAD(&smcd->vlan);
+ smcd->event_wq = alloc_ordered_workqueue("ism_evt_wq-%s)",
+ WQ_MEM_RECLAIM, name);
+ return smcd;
+}
+EXPORT_SYMBOL_GPL(smcd_alloc_dev);
+
+int smcd_register_dev(struct smcd_dev *smcd)
+{
+ spin_lock(&smcd_dev_list.lock);
+ list_add_tail(&smcd->list, &smcd_dev_list.list);
+ spin_unlock(&smcd_dev_list.lock);
+
+ return device_add(&smcd->dev);
+}
+EXPORT_SYMBOL_GPL(smcd_register_dev);
+
+void smcd_unregister_dev(struct smcd_dev *smcd)
+{
+ spin_lock(&smcd_dev_list.lock);
+ list_del(&smcd->list);
+ spin_unlock(&smcd_dev_list.lock);
+ flush_workqueue(smcd->event_wq);
+ destroy_workqueue(smcd->event_wq);
+ smc_smcd_terminate(smcd, 0);
+
+ device_del(&smcd->dev);
+}
+EXPORT_SYMBOL_GPL(smcd_unregister_dev);
+
+void smcd_free_dev(struct smcd_dev *smcd)
+{
+ put_device(&smcd->dev);
+}
+EXPORT_SYMBOL_GPL(smcd_free_dev);
+
+/* SMCD Device event handler. Called from ISM device interrupt handler.
+ * Parameters are smcd device pointer,
+ * - event->type (0 --> DMB, 1 --> GID),
+ * - event->code (event code),
+ * - event->tok (either DMB token when event type 0, or GID when event type 1)
+ * - event->time (time of day)
+ * - event->info (debug info).
+ *
+ * Context:
+ * - Function called in IRQ context from ISM device driver event handler.
+ */
+void smcd_handle_event(struct smcd_dev *smcd, struct smcd_event *event)
+{
+ struct smc_ism_event_work *wrk;
+
+ /* copy event to event work queue, and let it be handled there */
+ wrk = kmalloc(sizeof(*wrk), GFP_ATOMIC);
+ if (!wrk)
+ return;
+ INIT_WORK(&wrk->work, smc_ism_event_work);
+ wrk->smcd = smcd;
+ wrk->event = *event;
+ queue_work(smcd->event_wq, &wrk->work);
+}
+EXPORT_SYMBOL_GPL(smcd_handle_event);
+
+/* SMCD Device interrupt handler. Called from ISM device interrupt handler.
+ * Parameters are smcd device pointer and DMB number. Find the connection and
+ * schedule the tasklet for this connection.
+ *
+ * Context:
+ * - Function called in IRQ context from ISM device driver IRQ handler.
+ */
+void smcd_handle_irq(struct smcd_dev *smcd, unsigned int dmbno)
+{
+ struct smc_connection *conn = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&smcd->lock, flags);
+ conn = smcd->conn[dmbno];
+ if (conn)
+ tasklet_schedule(&conn->rx_tsklet);
+ spin_unlock_irqrestore(&smcd->lock, flags);
+}
+EXPORT_SYMBOL_GPL(smcd_handle_irq);