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Diffstat (limited to 'net/caif/cfmuxl.c')
-rw-r--r--net/caif/cfmuxl.c119
1 files changed, 75 insertions, 44 deletions
diff --git a/net/caif/cfmuxl.c b/net/caif/cfmuxl.c
index fc249746857..2a56df7e0a4 100644
--- a/net/caif/cfmuxl.c
+++ b/net/caif/cfmuxl.c
@@ -9,6 +9,7 @@
#include <linux/stddef.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
+#include <linux/rculist.h>
#include <net/caif/cfpkt.h>
#include <net/caif/cfmuxl.h>
#include <net/caif/cfsrvl.h>
@@ -64,31 +65,31 @@ struct cflayer *cfmuxl_create(void)
int cfmuxl_set_uplayer(struct cflayer *layr, struct cflayer *up, u8 linkid)
{
struct cfmuxl *muxl = container_obj(layr);
- spin_lock(&muxl->receive_lock);
- cfsrvl_get(up);
- list_add(&up->node, &muxl->srvl_list);
- spin_unlock(&muxl->receive_lock);
+
+ spin_lock_bh(&muxl->receive_lock);
+ list_add_rcu(&up->node, &muxl->srvl_list);
+ spin_unlock_bh(&muxl->receive_lock);
return 0;
}
int cfmuxl_set_dnlayer(struct cflayer *layr, struct cflayer *dn, u8 phyid)
{
struct cfmuxl *muxl = (struct cfmuxl *) layr;
- spin_lock(&muxl->transmit_lock);
- list_add(&dn->node, &muxl->frml_list);
- spin_unlock(&muxl->transmit_lock);
+
+ spin_lock_bh(&muxl->transmit_lock);
+ list_add_rcu(&dn->node, &muxl->frml_list);
+ spin_unlock_bh(&muxl->transmit_lock);
return 0;
}
static struct cflayer *get_from_id(struct list_head *list, u16 id)
{
- struct list_head *node;
- struct cflayer *layer;
- list_for_each(node, list) {
- layer = list_entry(node, struct cflayer, node);
- if (layer->id == id)
- return layer;
+ struct cflayer *lyr;
+ list_for_each_entry_rcu(lyr, list, node) {
+ if (lyr->id == id)
+ return lyr;
}
+
return NULL;
}
@@ -96,41 +97,45 @@ struct cflayer *cfmuxl_remove_dnlayer(struct cflayer *layr, u8 phyid)
{
struct cfmuxl *muxl = container_obj(layr);
struct cflayer *dn;
- spin_lock(&muxl->transmit_lock);
- memset(muxl->dn_cache, 0, sizeof(muxl->dn_cache));
+ int idx = phyid % DN_CACHE_SIZE;
+
+ spin_lock_bh(&muxl->transmit_lock);
+ rcu_assign_pointer(muxl->dn_cache[idx], NULL);
dn = get_from_id(&muxl->frml_list, phyid);
- if (dn == NULL) {
- spin_unlock(&muxl->transmit_lock);
- return NULL;
- }
- list_del(&dn->node);
+ if (dn == NULL)
+ goto out;
+
+ list_del_rcu(&dn->node);
caif_assert(dn != NULL);
- spin_unlock(&muxl->transmit_lock);
+out:
+ spin_unlock_bh(&muxl->transmit_lock);
return dn;
}
-/* Invariant: lock is taken */
static struct cflayer *get_up(struct cfmuxl *muxl, u16 id)
{
struct cflayer *up;
int idx = id % UP_CACHE_SIZE;
- up = muxl->up_cache[idx];
+ up = rcu_dereference(muxl->up_cache[idx]);
if (up == NULL || up->id != id) {
+ spin_lock_bh(&muxl->receive_lock);
up = get_from_id(&muxl->srvl_list, id);
- muxl->up_cache[idx] = up;
+ rcu_assign_pointer(muxl->up_cache[idx], up);
+ spin_unlock_bh(&muxl->receive_lock);
}
return up;
}
-/* Invariant: lock is taken */
static struct cflayer *get_dn(struct cfmuxl *muxl, struct dev_info *dev_info)
{
struct cflayer *dn;
int idx = dev_info->id % DN_CACHE_SIZE;
- dn = muxl->dn_cache[idx];
+ dn = rcu_dereference(muxl->dn_cache[idx]);
if (dn == NULL || dn->id != dev_info->id) {
+ spin_lock_bh(&muxl->transmit_lock);
dn = get_from_id(&muxl->frml_list, dev_info->id);
- muxl->dn_cache[idx] = dn;
+ rcu_assign_pointer(muxl->dn_cache[idx], dn);
+ spin_unlock_bh(&muxl->transmit_lock);
}
return dn;
}
@@ -139,15 +144,17 @@ struct cflayer *cfmuxl_remove_uplayer(struct cflayer *layr, u8 id)
{
struct cflayer *up;
struct cfmuxl *muxl = container_obj(layr);
- spin_lock(&muxl->receive_lock);
- up = get_up(muxl, id);
+ int idx = id % UP_CACHE_SIZE;
+
+ spin_lock_bh(&muxl->receive_lock);
+ up = get_from_id(&muxl->srvl_list, id);
if (up == NULL)
goto out;
- memset(muxl->up_cache, 0, sizeof(muxl->up_cache));
- list_del(&up->node);
- cfsrvl_put(up);
+
+ rcu_assign_pointer(muxl->up_cache[idx], NULL);
+ list_del_rcu(&up->node);
out:
- spin_unlock(&muxl->receive_lock);
+ spin_unlock_bh(&muxl->receive_lock);
return up;
}
@@ -162,22 +169,28 @@ static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
cfpkt_destroy(pkt);
return -EPROTO;
}
-
- spin_lock(&muxl->receive_lock);
+ rcu_read_lock();
up = get_up(muxl, id);
- spin_unlock(&muxl->receive_lock);
+
if (up == NULL) {
- pr_info("Received data on unknown link ID = %d (0x%x) up == NULL",
- id, id);
+ pr_debug("Received data on unknown link ID = %d (0x%x)"
+ " up == NULL", id, id);
cfpkt_destroy(pkt);
/*
* Don't return ERROR, since modem misbehaves and sends out
* flow on before linksetup response.
*/
+
+ rcu_read_unlock();
return /* CFGLU_EPROT; */ 0;
}
+
+ /* We can't hold rcu_lock during receive, so take a ref count instead */
cfsrvl_get(up);
+ rcu_read_unlock();
+
ret = up->receive(up, pkt);
+
cfsrvl_put(up);
return ret;
}
@@ -185,31 +198,49 @@ static int cfmuxl_receive(struct cflayer *layr, struct cfpkt *pkt)
static int cfmuxl_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
struct cfmuxl *muxl = container_obj(layr);
+ int err;
u8 linkid;
struct cflayer *dn;
struct caif_payload_info *info = cfpkt_info(pkt);
BUG_ON(!info);
+
+ rcu_read_lock();
+
dn = get_dn(muxl, info->dev_info);
if (dn == NULL) {
- pr_warn("Send data on unknown phy ID = %d (0x%x)\n",
+ pr_debug("Send data on unknown phy ID = %d (0x%x)\n",
info->dev_info->id, info->dev_info->id);
+ rcu_read_unlock();
+ cfpkt_destroy(pkt);
return -ENOTCONN;
}
+
info->hdr_len += 1;
linkid = info->channel_id;
cfpkt_add_head(pkt, &linkid, 1);
- return dn->transmit(dn, pkt);
+
+ /* We can't hold rcu_lock during receive, so take a ref count instead */
+ cffrml_hold(dn);
+
+ rcu_read_unlock();
+
+ err = dn->transmit(dn, pkt);
+
+ cffrml_put(dn);
+ return err;
}
static void cfmuxl_ctrlcmd(struct cflayer *layr, enum caif_ctrlcmd ctrl,
int phyid)
{
struct cfmuxl *muxl = container_obj(layr);
- struct list_head *node, *next;
struct cflayer *layer;
- list_for_each_safe(node, next, &muxl->srvl_list) {
- layer = list_entry(node, struct cflayer, node);
- if (cfsrvl_phyid_match(layer, phyid))
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(layer, &muxl->srvl_list, node) {
+ if (cfsrvl_phyid_match(layer, phyid) && layer->ctrlcmd)
+ /* NOTE: ctrlcmd is not allowed to block */
layer->ctrlcmd(layer, ctrl, phyid);
}
+ rcu_read_unlock();
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-29 19:01:26 +0000