@@ -200,23 +200,24 @@ static int hfi1_file_open(struct inode *inode, struct file *fp)
fd = kzalloc(sizeof(*fd), GFP_KERNEL);
- if (fd) {
- fd->rec_cpu_num = -1; /* no cpu affinity by default */
- fd->mm = current->mm;
- mmgrab(fd->mm);
- fd->dd = dd;
- kobject_get(&fd->dd->kobj);
- fp->private_data = fd;
- } else {
- fp->private_data = NULL;
-
- if (atomic_dec_and_test(&dd->user_refcount))
- complete(&dd->user_comp);
-
- return -ENOMEM;
- }
-
+ if (!fd || init_srcu_struct(&fd->pq_srcu))
+ goto nomem;
+ spin_lock_init(&fd->pq_rcu_lock);
+ spin_lock_init(&fd->tid_lock);
+ spin_lock_init(&fd->invalid_lock);
+ fd->rec_cpu_num = -1; /* no cpu affinity by default */
+ fd->mm = current->mm;
+ mmgrab(fd->mm);
+ fd->dd = dd;
+ kobject_get(&fd->dd->kobj);
+ fp->private_data = fd;
return 0;
+nomem:
+ kfree(fd);
+ fp->private_data = NULL;
+ if (atomic_dec_and_test(&dd->user_refcount))
+ complete(&dd->user_comp);
+ return -ENOMEM;
}
static long hfi1_file_ioctl(struct file *fp, unsigned int cmd,
@@ -301,21 +302,30 @@ static long hfi1_file_ioctl(struct file *fp, unsigned int cmd,
static ssize_t hfi1_write_iter(struct kiocb *kiocb, struct iov_iter *from)
{
struct hfi1_filedata *fd = kiocb->ki_filp->private_data;
- struct hfi1_user_sdma_pkt_q *pq = fd->pq;
+ struct hfi1_user_sdma_pkt_q *pq;
struct hfi1_user_sdma_comp_q *cq = fd->cq;
int done = 0, reqs = 0;
unsigned long dim = from->nr_segs;
+ int idx;
- if (!cq || !pq)
+ idx = srcu_read_lock(&fd->pq_srcu);
+ pq = srcu_dereference(fd->pq, &fd->pq_srcu);
+ if (!cq || !pq) {
+ srcu_read_unlock(&fd->pq_srcu, idx);
return -EIO;
+ }
- if (!iter_is_iovec(from) || !dim)
+ if (!iter_is_iovec(from) || !dim) {
+ srcu_read_unlock(&fd->pq_srcu, idx);
return -EINVAL;
+ }
trace_hfi1_sdma_request(fd->dd, fd->uctxt->ctxt, fd->subctxt, dim);
- if (atomic_read(&pq->n_reqs) == pq->n_max_reqs)
+ if (atomic_read(&pq->n_reqs) == pq->n_max_reqs) {
+ srcu_read_unlock(&fd->pq_srcu, idx);
return -ENOSPC;
+ }
while (dim) {
int ret;
@@ -333,6 +343,7 @@ static ssize_t hfi1_write_iter(struct kiocb *kiocb, struct iov_iter *from)
reqs++;
}
+ srcu_read_unlock(&fd->pq_srcu, idx);
return reqs;
}
@@ -707,6 +718,7 @@ static int hfi1_file_close(struct inode *inode, struct file *fp)
if (atomic_dec_and_test(&dd->user_refcount))
complete(&dd->user_comp);
+ cleanup_srcu_struct(&fdata->pq_srcu);
kfree(fdata);
return 0;
}
@@ -1444,10 +1444,13 @@ static inline bool hfi1_vnic_is_rsm_full(struct hfi1_devdata *dd, int spare)
/* Private data for file operations */
struct hfi1_filedata {
+ struct srcu_struct pq_srcu;
struct hfi1_devdata *dd;
struct hfi1_ctxtdata *uctxt;
struct hfi1_user_sdma_comp_q *cq;
- struct hfi1_user_sdma_pkt_q *pq;
+ /* update side lock for SRCU */
+ spinlock_t pq_rcu_lock;
+ struct hfi1_user_sdma_pkt_q __rcu *pq;
u16 subctxt;
/* for cpu affinity; -1 if none */
int rec_cpu_num;
@@ -87,9 +87,6 @@ int hfi1_user_exp_rcv_init(struct hfi1_filedata *fd,
{
int ret = 0;
- spin_lock_init(&fd->tid_lock);
- spin_lock_init(&fd->invalid_lock);
-
fd->entry_to_rb = kcalloc(uctxt->expected_count,
sizeof(struct rb_node *),
GFP_KERNEL);
@@ -179,7 +179,6 @@ int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
pq = kzalloc(sizeof(*pq), GFP_KERNEL);
if (!pq)
return -ENOMEM;
-
pq->dd = dd;
pq->ctxt = uctxt->ctxt;
pq->subctxt = fd->subctxt;
@@ -236,7 +235,7 @@ int hfi1_user_sdma_alloc_queues(struct hfi1_ctxtdata *uctxt,
goto pq_mmu_fail;
}
- fd->pq = pq;
+ rcu_assign_pointer(fd->pq, pq);
fd->cq = cq;
return 0;
@@ -264,8 +263,14 @@ int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd,
trace_hfi1_sdma_user_free_queues(uctxt->dd, uctxt->ctxt, fd->subctxt);
- pq = fd->pq;
+ spin_lock(&fd->pq_rcu_lock);
+ pq = srcu_dereference_check(fd->pq, &fd->pq_srcu,
+ lockdep_is_held(&fd->pq_rcu_lock));
if (pq) {
+ rcu_assign_pointer(fd->pq, NULL);
+ spin_unlock(&fd->pq_rcu_lock);
+ synchronize_srcu(&fd->pq_srcu);
+ /* at this point there can be no more new requests */
if (pq->handler)
hfi1_mmu_rb_unregister(pq->handler);
iowait_sdma_drain(&pq->busy);
@@ -277,7 +282,8 @@ int hfi1_user_sdma_free_queues(struct hfi1_filedata *fd,
kfree(pq->req_in_use);
kmem_cache_destroy(pq->txreq_cache);
kfree(pq);
- fd->pq = NULL;
+ } else {
+ spin_unlock(&fd->pq_rcu_lock);
}
if (fd->cq) {
vfree(fd->cq->comps);
@@ -321,7 +327,8 @@ int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
{
int ret = 0, i;
struct hfi1_ctxtdata *uctxt = fd->uctxt;
- struct hfi1_user_sdma_pkt_q *pq = fd->pq;
+ struct hfi1_user_sdma_pkt_q *pq =
+ srcu_dereference(fd->pq, &fd->pq_srcu);
struct hfi1_user_sdma_comp_q *cq = fd->cq;
struct hfi1_devdata *dd = pq->dd;
unsigned long idx = 0;