IB/hfi1: Protect context array set/clear with spinlock
The rcd array can be accessed from user context or during interrupts.
Protecting this with a mutex isn't a good idea because the mutex should
not be used from an IRQ.
Protect the allocation and freeing of rcd array elements with a
spinlock.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/hw/hfi1/init.c b/drivers/infiniband/hw/hfi1/init.c
index da7cd5b..23f0bbc 100644
--- a/drivers/infiniband/hw/hfi1/init.c
+++ b/drivers/infiniband/hw/hfi1/init.c
@@ -126,71 +126,67 @@ static struct idr hfi1_unit_table;
u32 hfi1_cpulist_count;
unsigned long *hfi1_cpulist;
-/*
- * Common code for creating the receive context array.
- */
-int hfi1_create_ctxts(struct hfi1_devdata *dd)
+static int hfi1_create_kctxt(struct hfi1_devdata *dd,
+ struct hfi1_pportdata *ppd)
{
- u16 i;
+ struct hfi1_ctxtdata *rcd;
int ret;
/* Control context has to be always 0 */
BUILD_BUG_ON(HFI1_CTRL_CTXT != 0);
- dd->rcd = kzalloc_node(dd->num_rcv_contexts * sizeof(*dd->rcd),
- GFP_KERNEL, dd->node);
- if (!dd->rcd)
- goto nomem;
-
- /* create one or more kernel contexts */
- for (i = 0; i < dd->first_dyn_alloc_ctxt; ++i) {
- struct hfi1_pportdata *ppd;
- struct hfi1_ctxtdata *rcd;
-
- ppd = dd->pport + (i % dd->num_pports);
-
- /* dd->rcd[i] gets assigned inside the callee */
- rcd = hfi1_create_ctxtdata(ppd, i, dd->node);
- if (!rcd) {
- dd_dev_err(dd,
- "Unable to allocate kernel receive context, failing\n");
- goto nomem;
- }
- /*
- * Set up the kernel context flags here and now because they
- * use default values for all receive side memories. User
- * contexts will be handled as they are created.
- */
- rcd->flags = HFI1_CAP_KGET(MULTI_PKT_EGR) |
- HFI1_CAP_KGET(NODROP_RHQ_FULL) |
- HFI1_CAP_KGET(NODROP_EGR_FULL) |
- HFI1_CAP_KGET(DMA_RTAIL);
-
- /* Control context must use DMA_RTAIL */
- if (rcd->ctxt == HFI1_CTRL_CTXT)
- rcd->flags |= HFI1_CAP_DMA_RTAIL;
- rcd->seq_cnt = 1;
-
- rcd->sc = sc_alloc(dd, SC_ACK, rcd->rcvhdrqentsize, dd->node);
- if (!rcd->sc) {
- dd_dev_err(dd,
- "Unable to allocate kernel send context, failing\n");
- goto nomem;
- }
-
- hfi1_init_ctxt(rcd->sc);
+ ret = hfi1_create_ctxtdata(ppd, dd->node, &rcd);
+ if (ret < 0) {
+ dd_dev_err(dd, "Kernel receive context allocation failed\n");
+ return ret;
}
/*
- * Initialize aspm, to be done after gen3 transition and setting up
- * contexts and before enabling interrupts
+ * Set up the kernel context flags here and now because they use
+ * default values for all receive side memories. User contexts will
+ * be handled as they are created.
*/
- aspm_init(dd);
+ rcd->flags = HFI1_CAP_KGET(MULTI_PKT_EGR) |
+ HFI1_CAP_KGET(NODROP_RHQ_FULL) |
+ HFI1_CAP_KGET(NODROP_EGR_FULL) |
+ HFI1_CAP_KGET(DMA_RTAIL);
+
+ /* Control context must use DMA_RTAIL */
+ if (rcd->ctxt == HFI1_CTRL_CTXT)
+ rcd->flags |= HFI1_CAP_DMA_RTAIL;
+ rcd->seq_cnt = 1;
+
+ rcd->sc = sc_alloc(dd, SC_ACK, rcd->rcvhdrqentsize, dd->node);
+ if (!rcd->sc) {
+ dd_dev_err(dd, "Kernel send context allocation failed\n");
+ return -ENOMEM;
+ }
+ hfi1_init_ctxt(rcd->sc);
return 0;
-nomem:
- ret = -ENOMEM;
+}
+/*
+ * Create the receive context array and one or more kernel contexts
+ */
+int hfi1_create_kctxts(struct hfi1_devdata *dd)
+{
+ u16 i;
+ int ret;
+
+ dd->rcd = kzalloc_node(dd->num_rcv_contexts * sizeof(*dd->rcd),
+ GFP_KERNEL, dd->node);
+ if (!dd->rcd)
+ return -ENOMEM;
+
+ for (i = 0; i < dd->first_dyn_alloc_ctxt; ++i) {
+ ret = hfi1_create_kctxt(dd, dd->pport);
+ if (ret)
+ goto bail;
+ }
+
+ return 0;
+bail:
for (i = 0; dd->rcd && i < dd->first_dyn_alloc_ctxt; ++i)
hfi1_rcd_put(dd->rcd[i]);
@@ -208,6 +204,11 @@ static void hfi1_rcd_init(struct hfi1_ctxtdata *rcd)
kref_init(&rcd->kref);
}
+/**
+ * hfi1_rcd_free - When reference is zero clean up.
+ * @kref: pointer to an initialized rcd data structure
+ *
+ */
static void hfi1_rcd_free(struct kref *kref)
{
struct hfi1_ctxtdata *rcd =
@@ -217,6 +218,12 @@ static void hfi1_rcd_free(struct kref *kref)
kfree(rcd);
}
+/**
+ * hfi1_rcd_put - decrement reference for rcd
+ * @rcd: pointer to an initialized rcd data structure
+ *
+ * Use this to put a reference after the init.
+ */
int hfi1_rcd_put(struct hfi1_ctxtdata *rcd)
{
if (rcd)
@@ -225,16 +232,58 @@ int hfi1_rcd_put(struct hfi1_ctxtdata *rcd)
return 0;
}
+/**
+ * hfi1_rcd_get - increment reference for rcd
+ * @rcd: pointer to an initialized rcd data structure
+ *
+ * Use this to get a reference after the init.
+ */
void hfi1_rcd_get(struct hfi1_ctxtdata *rcd)
{
kref_get(&rcd->kref);
}
+/**
+ * allocate_rcd_index - allocate an rcd index from the rcd array
+ * @dd: pointer to a valid devdata structure
+ * @rcd: rcd data structure to assign
+ * @index: pointer to index that is allocated
+ *
+ * Find an empty index in the rcd array, and assign the given rcd to it.
+ * If the array is full, we are EBUSY.
+ *
+ */
+static u16 allocate_rcd_index(struct hfi1_devdata *dd,
+ struct hfi1_ctxtdata *rcd, u16 *index)
+{
+ unsigned long flags;
+ u16 ctxt;
+
+ spin_lock_irqsave(&dd->uctxt_lock, flags);
+ for (ctxt = 0; ctxt < dd->num_rcv_contexts; ctxt++)
+ if (!dd->rcd[ctxt])
+ break;
+
+ if (ctxt < dd->num_rcv_contexts) {
+ rcd->ctxt = ctxt;
+ dd->rcd[ctxt] = rcd;
+ hfi1_rcd_init(rcd);
+ }
+ spin_unlock_irqrestore(&dd->uctxt_lock, flags);
+
+ if (ctxt >= dd->num_rcv_contexts)
+ return -EBUSY;
+
+ *index = ctxt;
+
+ return 0;
+}
+
/*
* Common code for user and kernel context setup.
*/
-struct hfi1_ctxtdata *hfi1_create_ctxtdata(struct hfi1_pportdata *ppd, u16 ctxt,
- int numa)
+int hfi1_create_ctxtdata(struct hfi1_pportdata *ppd, int numa,
+ struct hfi1_ctxtdata **context)
{
struct hfi1_devdata *dd = ppd->dd;
struct hfi1_ctxtdata *rcd;
@@ -248,9 +297,18 @@ struct hfi1_ctxtdata *hfi1_create_ctxtdata(struct hfi1_pportdata *ppd, u16 ctxt,
rcd = kzalloc_node(sizeof(*rcd), GFP_KERNEL, numa);
if (rcd) {
u32 rcvtids, max_entries;
+ u16 ctxt;
+ int ret;
hfi1_cdbg(PROC, "setting up context %u\n", ctxt);
+ ret = allocate_rcd_index(dd, rcd, &ctxt);
+ if (ret) {
+ *context = NULL;
+ kfree(rcd);
+ return ret;
+ }
+
INIT_LIST_HEAD(&rcd->qp_wait_list);
hfi1_exp_tid_group_init(&rcd->tid_group_list);
hfi1_exp_tid_group_init(&rcd->tid_used_list);
@@ -258,8 +316,6 @@ struct hfi1_ctxtdata *hfi1_create_ctxtdata(struct hfi1_pportdata *ppd, u16 ctxt,
rcd->ppd = ppd;
rcd->dd = dd;
__set_bit(0, rcd->in_use_ctxts);
- rcd->ctxt = ctxt;
- dd->rcd[ctxt] = rcd;
rcd->numa_id = numa;
rcd->rcv_array_groups = dd->rcv_entries.ngroups;
@@ -363,15 +419,34 @@ struct hfi1_ctxtdata *hfi1_create_ctxtdata(struct hfi1_pportdata *ppd, u16 ctxt,
goto bail;
}
- hfi1_rcd_init(rcd);
+ *context = rcd;
+ return 0;
}
- return rcd;
+
bail:
- dd->rcd[ctxt] = NULL;
- kfree(rcd->egrbufs.rcvtids);
- kfree(rcd->egrbufs.buffers);
- kfree(rcd);
- return NULL;
+ *context = NULL;
+ hfi1_free_ctxt(dd, rcd);
+ return -ENOMEM;
+}
+
+/**
+ * hfi1_free_ctxt
+ * @dd: Pointer to a valid device
+ * @rcd: pointer to an initialized rcd data structure
+ *
+ * This is the "free" to match the _create_ctxtdata (alloc) function.
+ * This is the final "put" for the kref.
+ */
+void hfi1_free_ctxt(struct hfi1_devdata *dd, struct hfi1_ctxtdata *rcd)
+{
+ unsigned long flags;
+
+ if (rcd) {
+ spin_lock_irqsave(&dd->uctxt_lock, flags);
+ dd->rcd[rcd->ctxt] = NULL;
+ spin_unlock_irqrestore(&dd->uctxt_lock, flags);
+ hfi1_rcd_put(rcd);
+ }
}
/*