qcacmn: Add QDF cpu hotplug APIs

Currently, there are two consumers of the Linux kernel CPU hotplug APIs.
Besides being problematic for not being operating system agnostic,
different versions of the Linux kernel export different CPU hotplug
APIs. In order to consolidate the various abstractions for different
operating systems and API versions, create a CPU hotplug abstraction in
QDF.

Change-Id: Ib17c6e3ed3a87a90a82d909a6c493360cab27855
CRs-Fixed: 2132632

qdf/src/qdf_cpuhp.c

@@ -0,0 +1,157 @@
+/*
+ * Copyright (c) 2017 The Linux Foundation. All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for
+ * any purpose with or without fee is hereby granted, provided that the
+ * above copyright notice and this permission notice appear in all
+ * copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/**
+ * DOC: qdf_cpuhp (CPU hotplug)
+ * QCA driver framework (QDF) CPU hotplug APIs
+ */
+
+#include "qdf_cpuhp.h"
+#include "i_qdf_cpuhp.h"
+#include "qdf_list.h"
+#include "qdf_lock.h"
+
+static qdf_mutex_t qdf_cpuhp_lock;
+static qdf_list_t qdf_cpuhp_handlers;
+
+struct qdf_cpuhp_handler {
+	qdf_list_node_t node;
+	void *context;
+	qdf_cpuhp_callback up_callback;
+	qdf_cpuhp_callback down_callback;
+};
+
+static void qdf_cpuhp_on_up(uint32_t cpu)
+{
+	QDF_STATUS status;
+	qdf_list_node_t *node;
+
+	qdf_mutex_acquire(&qdf_cpuhp_lock);
+
+	status = qdf_list_peek_front(&qdf_cpuhp_handlers, &node);
+	while (QDF_IS_STATUS_SUCCESS(status)) {
+		struct qdf_cpuhp_handler *handler =
+			qdf_container_of(node, struct qdf_cpuhp_handler, node);
+		if (handler->up_callback)
+			handler->up_callback(handler->context, cpu);
+
+		status = qdf_list_peek_next(&qdf_cpuhp_handlers, node, &node);
+	}
+
+	qdf_mutex_release(&qdf_cpuhp_lock);
+}
+
+static void qdf_cpuhp_on_down(uint32_t cpu)
+{
+	QDF_STATUS status;
+	qdf_list_node_t *node;
+
+	qdf_mutex_acquire(&qdf_cpuhp_lock);
+
+	status = qdf_list_peek_front(&qdf_cpuhp_handlers, &node);
+	while (QDF_IS_STATUS_SUCCESS(status)) {
+		struct qdf_cpuhp_handler *handler =
+			qdf_container_of(node, struct qdf_cpuhp_handler, node);
+		if (handler->down_callback)
+			handler->down_callback(handler->context, cpu);
+
+		status = qdf_list_peek_next(&qdf_cpuhp_handlers, node, &node);
+	}
+
+	qdf_mutex_release(&qdf_cpuhp_lock);
+}
+
+QDF_STATUS qdf_cpuhp_init(void)
+{
+	QDF_STATUS status;
+
+	status = qdf_mutex_create(&qdf_cpuhp_lock);
+	if (QDF_IS_STATUS_ERROR(status))
+		return status;
+
+	qdf_list_create(&qdf_cpuhp_handlers, 0);
+
+	__qdf_cpuhp_os_init(qdf_cpuhp_on_up, qdf_cpuhp_on_down);
+
+	return QDF_STATUS_SUCCESS;
+}
+
+QDF_STATUS qdf_cpuhp_deinit(void)
+{
+	__qdf_cpuhp_os_deinit();
+	qdf_list_destroy(&qdf_cpuhp_handlers);
+	return qdf_mutex_destroy(&qdf_cpuhp_lock);
+}
+
+QDF_STATUS qdf_cpuhp_register(struct qdf_cpuhp_handler **out_handler,
+			      void *context,
+			      qdf_cpuhp_callback up_callback,
+			      qdf_cpuhp_callback down_callback)
+{
+	QDF_STATUS status;
+	struct qdf_cpuhp_handler *handler;
+
+	*out_handler = NULL;
+
+	handler = qdf_mem_malloc(sizeof(*handler));
+	if (!handler)
+		return QDF_STATUS_E_NOMEM;
+
+	handler->context = context;
+	handler->up_callback = up_callback;
+	handler->down_callback = down_callback;
+
+	status = qdf_mutex_acquire(&qdf_cpuhp_lock);
+	if (QDF_IS_STATUS_ERROR(status))
+		goto free_handler;
+
+	status = qdf_list_insert_back(&qdf_cpuhp_handlers, &handler->node);
+	if (QDF_IS_STATUS_ERROR(status))
+		goto release_lock;
+
+	/* this can fail, but there isn't a good way to recover... */
+	qdf_mutex_release(&qdf_cpuhp_lock);
+
+	*out_handler = handler;
+
+	return QDF_STATUS_SUCCESS;
+
+release_lock:
+	qdf_mutex_release(&qdf_cpuhp_lock);
+
+free_handler:
+	qdf_mem_free(handler);
+
+	return status;
+}
+
+void qdf_cpuhp_unregister(struct qdf_cpuhp_handler **out_handler)
+{
+	struct qdf_cpuhp_handler *handler = *out_handler;
+
+	QDF_BUG(handler);
+	if (!handler)
+		return;
+
+	qdf_mutex_acquire(&qdf_cpuhp_lock);
+	qdf_list_remove_node(&qdf_cpuhp_handlers, &handler->node);
+	qdf_mutex_release(&qdf_cpuhp_lock);
+
+	*out_handler = NULL;
+}
+