[PATCH 05/17] drm/amdkfd: Clean up kfd_wait_on_events
Felix Kuehling
Felix.Kuehling at amd.com
Fri Oct 27 23:35:22 UTC 2017
Cleaned up the code while resolving some potential bugs and
inconsistencies in the process.
Clean-ups:
* Remove enum kfd_event_wait_result, which duplicates
KFD_IOC_EVENT_RESULT definitions
* alloc_event_waiters can be called without holding p->event_mutex
* Return an error code from copy_signaled_event_data instead of bool
* Clean up error handling code paths to minimize duplication in
kfd_wait_on_events
Fixes:
* Consistently return an error code from kfd_wait_on_events and set
wait_result to KFD_IOC_WAIT_RESULT_FAIL in all failure cases.
* Always call free_waiters while holding p->event_mutex
* copy_signaled_event_data might sleep. Don't call it while the task state
is TASK_INTERRUPTIBLE.
Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
Acked-by: Oded Gabbay <oded.gabbay at gmail.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 5 +--
drivers/gpu/drm/amd/amdkfd/kfd_events.c | 71 ++++++++++++++------------------
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 8 +---
3 files changed, 32 insertions(+), 52 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 0ef82b2..a25321f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -835,15 +835,12 @@ static int kfd_ioctl_wait_events(struct file *filp, struct kfd_process *p,
void *data)
{
struct kfd_ioctl_wait_events_args *args = data;
- enum kfd_event_wait_result wait_result;
int err;
err = kfd_wait_on_events(p, args->num_events,
(void __user *)args->events_ptr,
(args->wait_for_all != 0),
- args->timeout, &wait_result);
-
- args->wait_result = wait_result;
+ args->timeout, &args->wait_result);
return err;
}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
index 1efd6a8..33cafbb 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
@@ -668,7 +668,7 @@ static bool test_event_condition(bool all, uint32_t num_events,
* Copy event specific data, if defined.
* Currently only memory exception events have additional data to copy to user
*/
-static bool copy_signaled_event_data(uint32_t num_events,
+static int copy_signaled_event_data(uint32_t num_events,
struct kfd_event_waiter *event_waiters,
struct kfd_event_data __user *data)
{
@@ -686,11 +686,11 @@ static bool copy_signaled_event_data(uint32_t num_events,
src = &event->memory_exception_data;
if (copy_to_user(dst, src,
sizeof(struct kfd_hsa_memory_exception_data)))
- return false;
+ return -EFAULT;
}
}
- return true;
+ return 0;
}
@@ -727,7 +727,7 @@ static void free_waiters(uint32_t num_events, struct kfd_event_waiter *waiters)
int kfd_wait_on_events(struct kfd_process *p,
uint32_t num_events, void __user *data,
bool all, uint32_t user_timeout_ms,
- enum kfd_event_wait_result *wait_result)
+ uint32_t *wait_result)
{
struct kfd_event_data __user *events =
(struct kfd_event_data __user *) data;
@@ -737,18 +737,18 @@ int kfd_wait_on_events(struct kfd_process *p,
struct kfd_event_waiter *event_waiters = NULL;
long timeout = user_timeout_to_jiffies(user_timeout_ms);
+ event_waiters = alloc_event_waiters(num_events);
+ if (!event_waiters) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
mutex_lock(&p->event_mutex);
/* Set to something unreasonable - this is really
* just a bool for now.
*/
- *wait_result = KFD_WAIT_TIMEOUT;
-
- event_waiters = alloc_event_waiters(num_events);
- if (!event_waiters) {
- ret = -ENOMEM;
- goto fail;
- }
+ *wait_result = KFD_IOC_WAIT_RESULT_TIMEOUT;
for (i = 0; i < num_events; i++) {
struct kfd_event_data event_data;
@@ -756,23 +756,21 @@ int kfd_wait_on_events(struct kfd_process *p,
if (copy_from_user(&event_data, &events[i],
sizeof(struct kfd_event_data))) {
ret = -EFAULT;
- goto fail;
+ goto out_unlock;
}
ret = init_event_waiter_get_status(p, &event_waiters[i],
event_data.event_id, i);
if (ret)
- goto fail;
+ goto out_unlock;
}
/* Check condition once. */
if (test_event_condition(all, num_events, event_waiters)) {
- if (copy_signaled_event_data(num_events,
- event_waiters, events))
- *wait_result = KFD_WAIT_COMPLETE;
- else
- *wait_result = KFD_WAIT_ERROR;
- free_waiters(num_events, event_waiters);
+ *wait_result = KFD_IOC_WAIT_RESULT_COMPLETE;
+ ret = copy_signaled_event_data(num_events,
+ event_waiters, events);
+ goto out_unlock;
} else {
/* Add to wait lists if we need to wait. */
for (i = 0; i < num_events; i++)
@@ -781,12 +779,6 @@ int kfd_wait_on_events(struct kfd_process *p,
mutex_unlock(&p->event_mutex);
- /* Return if all waits were already satisfied. */
- if (*wait_result != KFD_WAIT_TIMEOUT) {
- __set_current_state(TASK_RUNNING);
- return ret;
- }
-
while (true) {
if (fatal_signal_pending(current)) {
ret = -EINTR;
@@ -818,16 +810,12 @@ int kfd_wait_on_events(struct kfd_process *p,
set_current_state(TASK_INTERRUPTIBLE);
if (test_event_condition(all, num_events, event_waiters)) {
- if (copy_signaled_event_data(num_events,
- event_waiters, events))
- *wait_result = KFD_WAIT_COMPLETE;
- else
- *wait_result = KFD_WAIT_ERROR;
+ *wait_result = KFD_IOC_WAIT_RESULT_COMPLETE;
break;
}
if (timeout <= 0) {
- *wait_result = KFD_WAIT_TIMEOUT;
+ *wait_result = KFD_IOC_WAIT_RESULT_TIMEOUT;
break;
}
@@ -835,19 +823,20 @@ int kfd_wait_on_events(struct kfd_process *p,
}
__set_current_state(TASK_RUNNING);
+ /* copy_signaled_event_data may sleep. So this has to happen
+ * after the task state is set back to RUNNING.
+ */
+ if (!ret && *wait_result == KFD_IOC_WAIT_RESULT_COMPLETE)
+ ret = copy_signaled_event_data(num_events,
+ event_waiters, events);
+
mutex_lock(&p->event_mutex);
+out_unlock:
free_waiters(num_events, event_waiters);
mutex_unlock(&p->event_mutex);
-
- return ret;
-
-fail:
- if (event_waiters)
- free_waiters(num_events, event_waiters);
-
- mutex_unlock(&p->event_mutex);
-
- *wait_result = KFD_WAIT_ERROR;
+out:
+ if (ret)
+ *wait_result = KFD_IOC_WAIT_RESULT_FAIL;
return ret;
}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index 1a483a7..d3cf53a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -726,19 +726,13 @@ uint64_t kfd_get_number_elems(struct kfd_dev *kfd);
extern const struct kfd_event_interrupt_class event_interrupt_class_cik;
extern const struct kfd_device_global_init_class device_global_init_class_cik;
-enum kfd_event_wait_result {
- KFD_WAIT_COMPLETE,
- KFD_WAIT_TIMEOUT,
- KFD_WAIT_ERROR
-};
-
void kfd_event_init_process(struct kfd_process *p);
void kfd_event_free_process(struct kfd_process *p);
int kfd_event_mmap(struct kfd_process *process, struct vm_area_struct *vma);
int kfd_wait_on_events(struct kfd_process *p,
uint32_t num_events, void __user *data,
bool all, uint32_t user_timeout_ms,
- enum kfd_event_wait_result *wait_result);
+ uint32_t *wait_result);
void kfd_signal_event_interrupt(unsigned int pasid, uint32_t partial_id,
uint32_t valid_id_bits);
void kfd_signal_iommu_event(struct kfd_dev *dev,
--
2.7.4
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