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linux/net/smc/smc_ism.c
Hans Wippel 0512f69e38 net/smc: add SMC-D shutdown signal 
When a SMC-D link group is freed, a shutdown signal should be sent to
the peer to indicate that the link group is invalid. This patch adds the
shutdown signal to the SMC code.

Signed-off-by: Hans Wippel <hwippel@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-21 16:14:56 -08:00

370 lines
9.1 KiB
C
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// 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;
};
#define ISM_EVENT_REQUEST 0x0001
#define ISM_EVENT_RESPONSE 0x0002
#define ISM_EVENT_REQUEST_IR 0x00000001
#define ISM_EVENT_CODE_SHUTDOWN 0x80
#define ISM_EVENT_CODE_TESTLINK 0x83
union smcd_sw_event_info {
u64 info;
struct {
u8 uid[SMC_LGR_ID_SIZE];
unsigned short vlan_id;
u16 code;
};
};
static void smcd_handle_sw_event(struct smc_ism_event_work *wrk)
{
union smcd_sw_event_info ev_info;
ev_info.info = wrk->event.info;
switch (wrk->event.code) {
case ISM_EVENT_CODE_SHUTDOWN: /* Peer shut down DMBs */
smc_smcd_terminate(wrk->smcd, wrk->event.tok, ev_info.vlan_id);
break;
case ISM_EVENT_CODE_TESTLINK: /* Activity timer */
if (ev_info.code == ISM_EVENT_REQUEST) {
ev_info.code = ISM_EVENT_RESPONSE;
wrk->smcd->ops->signal_event(wrk->smcd,
wrk->event.tok,
ISM_EVENT_REQUEST_IR,
ISM_EVENT_CODE_TESTLINK,
ev_info.info);
}
break;
}
}
int smc_ism_signal_shutdown(struct smc_link_group *lgr)
{
int rc;
union smcd_sw_event_info ev_info;
memcpy(ev_info.uid, lgr->id, SMC_LGR_ID_SIZE);
ev_info.vlan_id = lgr->vlan_id;
ev_info.code = ISM_EVENT_REQUEST;
rc = lgr->smcd->ops->signal_event(lgr->smcd, lgr->peer_gid,
ISM_EVENT_REQUEST_IR,
ISM_EVENT_CODE_SHUTDOWN,
ev_info.info);
return rc;
}
/* 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, VLAN_VID_MASK);
break;
case ISM_EVENT_DMB:
break;
case ISM_EVENT_SWR: /* Software defined event */
smcd_handle_sw_event(wrk);
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, VLAN_VID_MASK);
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);
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