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/file_ops.c b/drivers/infiniband/hw/hfi1/file_ops.c
index a0c13fa..7361366 100644
--- a/drivers/infiniband/hw/hfi1/file_ops.c
+++ b/drivers/infiniband/hw/hfi1/file_ops.c
@@ -79,8 +79,8 @@ static int hfi1_file_mmap(struct file *fp, struct vm_area_struct *vma);
static u64 kvirt_to_phys(void *addr);
static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo);
-static int init_subctxts(struct hfi1_ctxtdata *uctxt,
- const struct hfi1_user_info *uinfo);
+static void init_subctxts(struct hfi1_ctxtdata *uctxt,
+ const struct hfi1_user_info *uinfo);
static int init_user_ctxt(struct hfi1_filedata *fd,
struct hfi1_ctxtdata *uctxt);
static void user_init(struct hfi1_ctxtdata *uctxt);
@@ -758,7 +758,6 @@ static int hfi1_file_close(struct inode *inode, struct file *fp)
goto done;
hfi1_cdbg(PROC, "freeing ctxt %u:%u", uctxt->ctxt, fdata->subctxt);
- mutex_lock(&hfi1_mutex);
flush_wc();
/* drain user sdma queue */
@@ -778,6 +777,7 @@ static int hfi1_file_close(struct inode *inode, struct file *fp)
HFI1_MAX_SHARED_CTXTS) + fdata->subctxt;
*ev = 0;
+ mutex_lock(&hfi1_mutex);
__clear_bit(fdata->subctxt, uctxt->in_use_ctxts);
fdata->uctxt = NULL;
hfi1_rcd_put(uctxt); /* fdata reference */
@@ -844,6 +844,38 @@ static u64 kvirt_to_phys(void *addr)
return paddr;
}
+static int complete_subctxt(struct hfi1_filedata *fd)
+{
+ int ret;
+
+ /*
+ * sub-context info can only be set up after the base context
+ * has been completed.
+ */
+ ret = wait_event_interruptible(
+ fd->uctxt->wait,
+ !test_bit(HFI1_CTXT_BASE_UNINIT, &fd->uctxt->event_flags));
+
+ if (test_bit(HFI1_CTXT_BASE_FAILED, &fd->uctxt->event_flags))
+ ret = -ENOMEM;
+
+ /* The only thing a sub context needs is the user_xxx stuff */
+ if (!ret) {
+ fd->rec_cpu_num = hfi1_get_proc_affinity(fd->uctxt->numa_id);
+ ret = init_user_ctxt(fd, fd->uctxt);
+ }
+
+ if (ret) {
+ hfi1_rcd_put(fd->uctxt);
+ fd->uctxt = NULL;
+ mutex_lock(&hfi1_mutex);
+ __clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
+ mutex_unlock(&hfi1_mutex);
+ }
+
+ return ret;
+}
+
static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
{
int ret;
@@ -854,24 +886,25 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
if (swmajor != HFI1_USER_SWMAJOR)
return -ENODEV;
+ if (uinfo->subctxt_cnt > HFI1_MAX_SHARED_CTXTS)
+ return -EINVAL;
+
swminor = uinfo->userversion & 0xffff;
+ /*
+ * Acquire the mutex to protect against multiple creations of what
+ * could be a shared base context.
+ */
mutex_lock(&hfi1_mutex);
/*
- * Get a sub context if necessary.
+ * Get a sub context if available (fd->uctxt will be set).
* ret < 0 error, 0 no context, 1 sub-context found
*/
- ret = 0;
- if (uinfo->subctxt_cnt) {
- ret = find_sub_ctxt(fd, uinfo);
- if (ret > 0)
- fd->rec_cpu_num =
- hfi1_get_proc_affinity(fd->uctxt->numa_id);
- }
+ ret = find_sub_ctxt(fd, uinfo);
/*
- * Allocate a base context if context sharing is not required or we
- * couldn't find a sub context.
+ * Allocate a base context if context sharing is not required or a
+ * sub context wasn't found.
*/
if (!ret)
ret = allocate_ctxt(fd, fd->dd, uinfo, &uctxt);
@@ -879,31 +912,10 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
mutex_unlock(&hfi1_mutex);
/* Depending on the context type, do the appropriate init */
- if (ret > 0) {
- /*
- * sub-context info can only be set up after the base
- * context has been completed.
- */
- ret = wait_event_interruptible(fd->uctxt->wait, !test_bit(
- HFI1_CTXT_BASE_UNINIT,
- &fd->uctxt->event_flags));
- if (test_bit(HFI1_CTXT_BASE_FAILED, &fd->uctxt->event_flags))
- ret = -ENOMEM;
-
- /* The only thing a sub context needs is the user_xxx stuff */
- if (!ret)
- ret = init_user_ctxt(fd, fd->uctxt);
-
- if (ret)
- clear_bit(fd->subctxt, fd->uctxt->in_use_ctxts);
-
- } else if (!ret) {
+ switch (ret) {
+ case 0:
ret = setup_base_ctxt(fd, uctxt);
if (uctxt->subctxt_cnt) {
- /* If there is an error, set the failed bit. */
- if (ret)
- set_bit(HFI1_CTXT_BASE_FAILED,
- &uctxt->event_flags);
/*
* Base context is done, notify anybody using a
* sub-context that is waiting for this completion
@@ -911,14 +923,12 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
clear_bit(HFI1_CTXT_BASE_UNINIT, &uctxt->event_flags);
wake_up(&uctxt->wait);
}
- if (ret)
- deallocate_ctxt(uctxt);
- }
-
- /* If an error occurred, clear the reference */
- if (ret && fd->uctxt) {
- hfi1_rcd_put(fd->uctxt);
- fd->uctxt = NULL;
+ break;
+ case 1:
+ ret = complete_subctxt(fd);
+ break;
+ default:
+ break;
}
return ret;
@@ -926,7 +936,7 @@ static int assign_ctxt(struct hfi1_filedata *fd, struct hfi1_user_info *uinfo)
/*
* The hfi1_mutex must be held when this function is called. It is
- * necessary to ensure serialized access to the bitmask in_use_ctxts.
+ * necessary to ensure serialized creation of shared contexts.
*/
static int find_sub_ctxt(struct hfi1_filedata *fd,
const struct hfi1_user_info *uinfo)
@@ -935,6 +945,9 @@ static int find_sub_ctxt(struct hfi1_filedata *fd,
struct hfi1_devdata *dd = fd->dd;
u16 subctxt;
+ if (!uinfo->subctxt_cnt)
+ return 0;
+
for (i = dd->first_dyn_alloc_ctxt; i < dd->num_rcv_contexts; i++) {
struct hfi1_ctxtdata *uctxt = dd->rcd[i];
@@ -983,7 +996,6 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
struct hfi1_ctxtdata **cd)
{
struct hfi1_ctxtdata *uctxt;
- u16 ctxt;
int ret, numa;
if (dd->flags & HFI1_FROZEN) {
@@ -997,22 +1009,9 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
return -EIO;
}
- /*
- * This check is sort of redundant to the next EBUSY error. It would
- * also indicate an inconsistancy in the driver if this value was
- * zero, but there were still contexts available.
- */
if (!dd->freectxts)
return -EBUSY;
- for (ctxt = dd->first_dyn_alloc_ctxt;
- ctxt < dd->num_rcv_contexts; ctxt++)
- if (!dd->rcd[ctxt])
- break;
-
- if (ctxt == dd->num_rcv_contexts)
- return -EBUSY;
-
/*
* If we don't have a NUMA node requested, preference is towards
* device NUMA node.
@@ -1022,11 +1021,10 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
numa = cpu_to_node(fd->rec_cpu_num);
else
numa = numa_node_id();
- uctxt = hfi1_create_ctxtdata(dd->pport, ctxt, numa);
- if (!uctxt) {
- dd_dev_err(dd,
- "Unable to allocate ctxtdata memory, failing open\n");
- return -ENOMEM;
+ ret = hfi1_create_ctxtdata(dd->pport, numa, &uctxt);
+ if (ret < 0) {
+ dd_dev_err(dd, "user ctxtdata allocation failed\n");
+ return ret;
}
hfi1_cdbg(PROC, "[%u:%u] pid %u assigned to CPU %d (NUMA %u)",
uctxt->ctxt, fd->subctxt, current->pid, fd->rec_cpu_num,
@@ -1035,8 +1033,7 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
/*
* Allocate and enable a PIO send context.
*/
- uctxt->sc = sc_alloc(dd, SC_USER, uctxt->rcvhdrqentsize,
- uctxt->dd->node);
+ uctxt->sc = sc_alloc(dd, SC_USER, uctxt->rcvhdrqentsize, dd->node);
if (!uctxt->sc) {
ret = -ENOMEM;
goto ctxdata_free;
@@ -1048,20 +1045,13 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
goto ctxdata_free;
/*
- * Setup sub context resources if the user-level has requested
+ * Setup sub context information if the user-level has requested
* sub contexts.
* This has to be done here so the rest of the sub-contexts find the
- * proper master.
+ * proper base context.
*/
- if (uinfo->subctxt_cnt) {
- ret = init_subctxts(uctxt, uinfo);
- /*
- * On error, we don't need to disable and de-allocate the
- * send context because it will be done during file close
- */
- if (ret)
- goto ctxdata_free;
- }
+ if (uinfo->subctxt_cnt)
+ init_subctxts(uctxt, uinfo);
uctxt->userversion = uinfo->userversion;
uctxt->flags = hfi1_cap_mask; /* save current flag state */
init_waitqueue_head(&uctxt->wait);
@@ -1081,9 +1071,7 @@ static int allocate_ctxt(struct hfi1_filedata *fd, struct hfi1_devdata *dd,
return 0;
ctxdata_free:
- *cd = NULL;
- dd->rcd[ctxt] = NULL;
- hfi1_rcd_put(uctxt);
+ hfi1_free_ctxt(dd, uctxt);
return ret;
}
@@ -1093,28 +1081,17 @@ static void deallocate_ctxt(struct hfi1_ctxtdata *uctxt)
hfi1_stats.sps_ctxts--;
if (++uctxt->dd->freectxts == uctxt->dd->num_user_contexts)
aspm_enable_all(uctxt->dd);
-
- /* _rcd_put() should be done after releasing mutex */
- uctxt->dd->rcd[uctxt->ctxt] = NULL;
mutex_unlock(&hfi1_mutex);
- hfi1_rcd_put(uctxt); /* dd reference */
+
+ hfi1_free_ctxt(uctxt->dd, uctxt);
}
-static int init_subctxts(struct hfi1_ctxtdata *uctxt,
- const struct hfi1_user_info *uinfo)
+static void init_subctxts(struct hfi1_ctxtdata *uctxt,
+ const struct hfi1_user_info *uinfo)
{
- u16 num_subctxts;
-
- num_subctxts = uinfo->subctxt_cnt;
- if (num_subctxts > HFI1_MAX_SHARED_CTXTS)
- return -EINVAL;
-
uctxt->subctxt_cnt = uinfo->subctxt_cnt;
uctxt->subctxt_id = uinfo->subctxt_id;
- uctxt->redirect_seq_cnt = 1;
set_bit(HFI1_CTXT_BASE_UNINIT, &uctxt->event_flags);
-
- return 0;
}
static int setup_subctxt(struct hfi1_ctxtdata *uctxt)
@@ -1302,8 +1279,8 @@ static int setup_base_ctxt(struct hfi1_filedata *fd,
return 0;
setup_failed:
- /* Call _free_ctxtdata, not _rcd_put(). We still need the context. */
- hfi1_free_ctxtdata(dd, uctxt);
+ set_bit(HFI1_CTXT_BASE_FAILED, &uctxt->event_flags);
+ deallocate_ctxt(uctxt);
return ret;
}