@@ -65,6 +65,20 @@ void buffer_zero_batch_task_init(struct buffer_zero_batch_task *task,
*/
void buffer_zero_batch_task_destroy(struct buffer_zero_batch_task *task);
+/**
+ * @brief Performs buffer zero comparison on a DSA batch task asynchronously.
+ *
+ * @param batch_task A pointer to the batch task.
+ * @param buf An array of memory buffers.
+ * @param count The number of buffers in the array.
+ * @param len The buffer length.
+ *
+ * @return Zero if successful, otherwise non-zero.
+ */
+int
+buffer_is_zero_dsa_batch_async(struct buffer_zero_batch_task *batch_task,
+ const void **buf, size_t count, size_t len);
+
/**
* @brief Initializes DSA devices.
*
@@ -470,6 +470,41 @@ poll_completion(struct dsa_completion_record *completion,
return 0;
}
+/**
+ * @brief Use CPU to complete a single zero page checking task.
+ *
+ * @param task A pointer to the task.
+ */
+static void
+task_cpu_fallback(struct buffer_zero_batch_task *task)
+{
+ assert(task->task_type == DSA_TASK);
+
+ struct dsa_completion_record *completion = &task->completions[0];
+ const uint8_t *buf;
+ size_t len;
+
+ if (completion->status == DSA_COMP_SUCCESS) {
+ return;
+ }
+
+ /*
+ * DSA was able to partially complete the operation. Check the
+ * result. If we already know this is not a zero page, we can
+ * return now.
+ */
+ if (completion->bytes_completed != 0 && completion->result != 0) {
+ task->results[0] = false;
+ return;
+ }
+
+ /* Let's fallback to use CPU to complete it. */
+ buf = (const uint8_t *)task->descriptors[0].src_addr;
+ len = task->descriptors[0].xfer_size;
+ task->results[0] = buffer_is_zero(buf + completion->bytes_completed,
+ len - completion->bytes_completed);
+}
+
/**
* @brief Complete a single DSA task in the batch task.
*
@@ -548,6 +583,62 @@ poll_batch_task_completion(struct buffer_zero_batch_task *batch_task)
}
}
+/**
+ * @brief Use CPU to complete the zero page checking batch task.
+ *
+ * @param batch_task A pointer to the batch task.
+ */
+static void
+batch_task_cpu_fallback(struct buffer_zero_batch_task *batch_task)
+{
+ assert(batch_task->task_type == DSA_BATCH_TASK);
+
+ struct dsa_completion_record *batch_completion =
+ &batch_task->batch_completion;
+ struct dsa_completion_record *completion;
+ uint8_t status;
+ const uint8_t *buf;
+ size_t len;
+ bool *results = batch_task->results;
+ uint32_t count = batch_task->batch_descriptor.desc_count;
+
+ // DSA is able to complete the entire batch task.
+ if (batch_completion->status == DSA_COMP_SUCCESS) {
+ assert(count == batch_completion->bytes_completed);
+ return;
+ }
+
+ /*
+ * DSA encounters some error and is not able to complete
+ * the entire batch task. Use CPU fallback.
+ */
+ for (int i = 0; i < count; i++) {
+ completion = &batch_task->completions[i];
+ status = completion->status;
+ if (status == DSA_COMP_SUCCESS) {
+ continue;
+ }
+ assert(status == DSA_COMP_PAGE_FAULT_NOBOF);
+
+ /*
+ * DSA was able to partially complete the operation. Check the
+ * result. If we already know this is not a zero page, we can
+ * return now.
+ */
+ if (completion->bytes_completed != 0 && completion->result != 0) {
+ results[i] = false;
+ continue;
+ }
+
+ /* Let's fallback to use CPU to complete it. */
+ buf = (uint8_t *)batch_task->descriptors[i].src_addr;
+ len = batch_task->descriptors[i].xfer_size;
+ results[i] =
+ buffer_is_zero(buf + completion->bytes_completed,
+ len - completion->bytes_completed);
+ }
+}
+
/**
* @brief Handles an asynchronous DSA batch task completion.
*
@@ -825,7 +916,6 @@ buffer_zero_batch_task_set(struct buffer_zero_batch_task *batch_task,
*
* @return int Zero if successful, otherwise an appropriate error code.
*/
-__attribute__((unused))
static int
buffer_zero_dsa_async(struct buffer_zero_batch_task *task,
const void *buf, size_t len)
@@ -844,7 +934,6 @@ buffer_zero_dsa_async(struct buffer_zero_batch_task *task,
* @param count The number of buffers.
* @param len The buffer length.
*/
-__attribute__((unused))
static int
buffer_zero_dsa_batch_async(struct buffer_zero_batch_task *batch_task,
const void **buf, size_t count, size_t len)
@@ -876,13 +965,29 @@ buffer_zero_dsa_completion(void *context)
*
* @param batch_task A pointer to the buffer zero comparison batch task.
*/
-__attribute__((unused))
static void
buffer_zero_dsa_wait(struct buffer_zero_batch_task *batch_task)
{
qemu_sem_wait(&batch_task->sem_task_complete);
}
+/**
+ * @brief Use CPU to complete the zero page checking task if DSA
+ * is not able to complete it.
+ *
+ * @param batch_task A pointer to the batch task.
+ */
+static void
+buffer_zero_cpu_fallback(struct buffer_zero_batch_task *batch_task)
+{
+ if (batch_task->task_type == DSA_TASK) {
+ task_cpu_fallback(batch_task);
+ } else {
+ assert(batch_task->task_type == DSA_BATCH_TASK);
+ batch_task_cpu_fallback(batch_task);
+ }
+}
+
/**
* @brief Check if DSA is running.
*
@@ -956,6 +1061,41 @@ void dsa_cleanup(void)
dsa_device_group_cleanup(&dsa_group);
}
+/**
+ * @brief Performs buffer zero comparison on a DSA batch task asynchronously.
+ *
+ * @param batch_task A pointer to the batch task.
+ * @param buf An array of memory buffers.
+ * @param count The number of buffers in the array.
+ * @param len The buffer length.
+ *
+ * @return Zero if successful, otherwise non-zero.
+ */
+int
+buffer_is_zero_dsa_batch_async(struct buffer_zero_batch_task *batch_task,
+ const void **buf, size_t count, size_t len)
+{
+ if (count <= 0 || count > batch_task->batch_size) {
+ return -1;
+ }
+
+ assert(batch_task != NULL);
+ assert(len != 0);
+ assert(buf != NULL);
+
+ if (count == 1) {
+ // DSA doesn't take batch operation with only 1 task.
+ buffer_zero_dsa_async(batch_task, buf[0], len);
+ } else {
+ buffer_zero_dsa_batch_async(batch_task, buf, count, len);
+ }
+
+ buffer_zero_dsa_wait(batch_task);
+ buffer_zero_cpu_fallback(batch_task);
+
+ return 0;
+}
+
#else
void buffer_zero_batch_task_init(struct buffer_zero_batch_task *task,
@@ -981,5 +1121,12 @@ void dsa_stop(void) {}
void dsa_cleanup(void) {}
+int
+buffer_is_zero_dsa_batch_async(struct buffer_zero_batch_task *batch_task,
+ const void **buf, size_t count, size_t len)
+{
+ exit(1);
+}
+
#endif