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/inc/qdf_cpuhp.h

@@ -0,0 +1,106 @@
+/*
+ * 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
+ */
+
+#ifndef __QDF_CPUHP_H
+#define __QDF_CPUHP_H
+
+#include "qdf_status.h"
+#include "qdf_types.h"
+
+/**
+ * struct qdf_cpuhp_handler - an opaque hotplug event registration handle
+ */
+struct qdf_cpuhp_handler;
+
+typedef void (*qdf_cpuhp_callback)(void *context, uint32_t cpu);
+
+#ifdef QCA_CONFIG_SMP
+/**
+ * qdf_cpuhp_init() - Initialize the CPU hotplug event infrastructure
+ *
+ * To be called once, globally.
+ *
+ * Return: None
+ */
+QDF_STATUS qdf_cpuhp_init(void);
+
+/**
+ * qdf_cpuhp_deinit() - De-initialize the CPU hotplug event infrastructure
+ *
+ * To be called once, globally.
+ *
+ * Return: None
+ */
+QDF_STATUS qdf_cpuhp_deinit(void);
+
+/**
+ * qdf_cpuhp_register() - Register for CPU up/down event notifications
+ * @handler: a double pointer to the event registration handle to allocate
+ * @context: an opaque context to pass back to event listeners
+ * @up_callback: the function pointer to invoke for CPU up events
+ * @down_callback: the function pointer to invoke for CPU down events
+ *
+ * "Up" happens just after the CPU is up. Inversely, "down" happens just before
+ * the CPU goes down.
+ *
+ * @handler will point to a valid memory address on success, or NULL on failure.
+ *
+ * Return: QDF_STATUS
+ */
+QDF_STATUS qdf_cpuhp_register(struct qdf_cpuhp_handler **handler,
+			      void *context,
+			      qdf_cpuhp_callback up_callback,
+			      qdf_cpuhp_callback down_callback);
+
+/**
+ * qdf_cpuhp_unregister() - Un-register for CPU up/down event notifications
+ * @handler: a double pointer to the event registration handle to de-allocate
+ *
+ * @handler point to NULL upon completion
+ *
+ * Return: None
+ */
+void qdf_cpuhp_unregister(struct qdf_cpuhp_handler **handler);
+#else
+QDF_STATUS qdf_cpuhp_init(void)
+{
+	return QDF_STATUS_SUCCESS;
+}
+
+QDF_STATUS qdf_cpuhp_deinit(void)
+{
+	return QDF_STATUS_SUCCESS;
+}
+
+QDF_STATUS qdf_cpuhp_register(struct qdf_cpuhp_handler **handler,
+			      void *context,
+			      qdf_cpuhp_callback up_callback,
+			      qdf_cpuhp_callback down_callback)
+{
+	return QDF_STATUS_SUCCESS;
+}
+
+void qdf_cpuhp_unregister(struct qdf_cpuhp_handler **handler) {}
+#endif /* QCA_CONFIG_SMP */
+
+#endif /* __QDF_CPUHP_H */

qdf/linux/src/i_qdf_cpuhp.h

@@ -0,0 +1,34 @@
+/*
+ * 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: i_qdf_cpuhp.h (CPU hotplug)
+ * Linux-specific definitions for QDF CPU hotplug API's
+ */
+
+#ifndef __I_QDF_CPUHP_H
+#define __I_QDF_CPUHP_H
+
+#include "linux/types.h"
+
+typedef void (*__qdf_cpuhp_emit)(uint32_t cpu);
+
+void __qdf_cpuhp_os_init(__qdf_cpuhp_emit on_up, __qdf_cpuhp_emit on_down);
+void __qdf_cpuhp_os_deinit(void);
+
+#endif /* __I_QDF_CPUHP_H */

qdf/linux/src/qdf_cpuhp.c

@@ -0,0 +1,119 @@
+/*
+ * 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
+ * This file provides OS dependent QDF CPU hotplug APIs
+ */
+
+#include "i_qdf_cpuhp.h"
+#include "qdf_trace.h"
+#include "linux/cpu.h"
+#include "linux/notifier.h"
+#include "linux/version.h"
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 6, 0)
+#include "linux/cpuhotplug.h"
+#endif
+
+static __qdf_cpuhp_emit __qdf_cpuhp_on_up;
+static __qdf_cpuhp_emit __qdf_cpuhp_on_down;
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 6, 0)
+static int qdf_cpuhp_legacy_handler(struct notifier_block *block,
+				    unsigned long state,
+				    void *hcpu)
+{
+	unsigned long cpu = (unsigned long)hcpu;
+
+	switch (state) {
+	case CPU_ONLINE:
+		__qdf_cpuhp_on_up(cpu);
+		break;
+
+	case CPU_DOWN_PREPARE:
+	case CPU_DOWN_PREPARE_FROZEN:
+		__qdf_cpuhp_on_down(cpu);
+		break;
+
+	default:
+		break;
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block qdf_cpuhp_notifier_block = {
+	.notifier_call = qdf_cpuhp_legacy_handler,
+};
+
+static inline void qdf_cpuhp_register_callbacks(void)
+{
+	register_hotcpu_notifier(&qdf_cpuhp_notifier_block);
+}
+
+static inline void qdf_cpuhp_unregister_callbacks(void)
+{
+	unregister_hotcpu_notifier(&qdf_cpuhp_notifier_block);
+}
+#else
+static enum cpuhp_state registered_hotplug_state;
+
+static int qdf_cpuhp_up_handler(unsigned int cpu)
+{
+	__qdf_cpuhp_on_up(cpu);
+
+	return 0;
+}
+
+static int qdf_cpuhp_down_handler(unsigned int cpu)
+{
+	__qdf_cpuhp_on_down(cpu);
+
+	return 0;
+}
+
+static inline void qdf_cpuhp_register_callbacks(void)
+{
+	registered_hotplug_state = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
+						     "wlan/qca-qdf:online",
+						     qdf_cpuhp_up_handler,
+						     qdf_cpuhp_down_handler);
+}
+
+static inline void qdf_cpuhp_unregister_callbacks(void)
+{
+	QDF_BUG(registered_hotplug_state);
+	if (registered_hotplug_state)
+		cpuhp_remove_state(registered_hotplug_state);
+}
+#endif /* KERNEL_VERSION(4, 6, 0) */
+
+void __qdf_cpuhp_os_init(__qdf_cpuhp_emit on_up, __qdf_cpuhp_emit on_down)
+{
+	__qdf_cpuhp_on_up = on_up;
+	__qdf_cpuhp_on_down = on_down;
+
+	qdf_cpuhp_register_callbacks();
+}
+
+void __qdf_cpuhp_os_deinit(void)
+{
+	qdf_cpuhp_unregister_callbacks();
+}
+

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;
+}
+