1 /*
2 * Copyright (C) 2010-2014, 2016-2017 ARM Limited. All rights reserved.
3 *
4 * This program is free software and is provided to you under the terms of the GNU General Public License version 2
5 * as published by the Free Software Foundation, and any use by you of this program is subject to the terms of such GNU licence.
6 *
7 * A copy of the licence is included with the program, and can also be obtained from Free Software
8 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
9 */
10
11 /**
12 * @file mali_osk_notification.c
13 * Implementation of the OS abstraction layer for the kernel device driver
14 */
15
16 #include "mali_osk.h"
17 #include "mali_kernel_common.h"
18
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22
23 /**
24 * Declaration of the notification queue object type
25 * Contains a linked list of notification pending delivery to user space.
26 * It also contains a wait queue of exclusive waiters blocked in the ioctl
27 * When a new notification is posted a single thread is resumed.
28 */
29 struct _mali_osk_notification_queue_t_struct {
30 spinlock_t mutex; /**< Mutex protecting the list */
31 wait_queue_head_t receive_queue; /**< Threads waiting for new entries to the queue */
32 struct list_head head; /**< List of notifications waiting to be picked up */
33 };
34
35 typedef struct _mali_osk_notification_wrapper_t_struct {
36 struct list_head list; /**< Internal linked list variable */
37 _mali_osk_notification_t data; /**< Notification data */
38 } _mali_osk_notification_wrapper_t;
39
_mali_osk_notification_queue_init(void)40 _mali_osk_notification_queue_t *_mali_osk_notification_queue_init(void)
41 {
42 _mali_osk_notification_queue_t *result;
43
44 result = (_mali_osk_notification_queue_t *)kmalloc(sizeof(_mali_osk_notification_queue_t), GFP_KERNEL);
45 if (NULL == result) return NULL;
46
47 spin_lock_init(&result->mutex);
48 init_waitqueue_head(&result->receive_queue);
49 INIT_LIST_HEAD(&result->head);
50
51 return result;
52 }
53
_mali_osk_notification_create(u32 type,u32 size)54 _mali_osk_notification_t *_mali_osk_notification_create(u32 type, u32 size)
55 {
56 /* OPT Recycling of notification objects */
57 _mali_osk_notification_wrapper_t *notification;
58
59 notification = (_mali_osk_notification_wrapper_t *)kmalloc(sizeof(_mali_osk_notification_wrapper_t) + size,
60 GFP_KERNEL | __GFP_HIGH | __GFP_RETRY_MAYFAIL);
61 if (NULL == notification) {
62 MALI_DEBUG_PRINT(1, ("Failed to create a notification object\n"));
63 return NULL;
64 }
65
66 /* Init the list */
67 INIT_LIST_HEAD(¬ification->list);
68
69 if (0 != size) {
70 notification->data.result_buffer = ((u8 *)notification) + sizeof(_mali_osk_notification_wrapper_t);
71 } else {
72 notification->data.result_buffer = NULL;
73 }
74
75 /* set up the non-allocating fields */
76 notification->data.notification_type = type;
77 notification->data.result_buffer_size = size;
78
79 /* all ok */
80 return &(notification->data);
81 }
82
_mali_osk_notification_delete(_mali_osk_notification_t * object)83 void _mali_osk_notification_delete(_mali_osk_notification_t *object)
84 {
85 _mali_osk_notification_wrapper_t *notification;
86 MALI_DEBUG_ASSERT_POINTER(object);
87
88 notification = container_of(object, _mali_osk_notification_wrapper_t, data);
89
90 /* Free the container */
91 kfree(notification);
92 }
93
_mali_osk_notification_queue_term(_mali_osk_notification_queue_t * queue)94 void _mali_osk_notification_queue_term(_mali_osk_notification_queue_t *queue)
95 {
96 _mali_osk_notification_t *result;
97 MALI_DEBUG_ASSERT_POINTER(queue);
98
99 while (_MALI_OSK_ERR_OK == _mali_osk_notification_queue_dequeue(queue, &result)) {
100 _mali_osk_notification_delete(result);
101 }
102
103 /* not much to do, just free the memory */
104 kfree(queue);
105 }
_mali_osk_notification_queue_send(_mali_osk_notification_queue_t * queue,_mali_osk_notification_t * object)106 void _mali_osk_notification_queue_send(_mali_osk_notification_queue_t *queue, _mali_osk_notification_t *object)
107 {
108 #if defined(MALI_UPPER_HALF_SCHEDULING)
109 unsigned long irq_flags;
110 #endif
111
112 _mali_osk_notification_wrapper_t *notification;
113 MALI_DEBUG_ASSERT_POINTER(queue);
114 MALI_DEBUG_ASSERT_POINTER(object);
115
116 notification = container_of(object, _mali_osk_notification_wrapper_t, data);
117
118 #if defined(MALI_UPPER_HALF_SCHEDULING)
119 spin_lock_irqsave(&queue->mutex, irq_flags);
120 #else
121 spin_lock(&queue->mutex);
122 #endif
123
124 list_add_tail(¬ification->list, &queue->head);
125
126 #if defined(MALI_UPPER_HALF_SCHEDULING)
127 spin_unlock_irqrestore(&queue->mutex, irq_flags);
128 #else
129 spin_unlock(&queue->mutex);
130 #endif
131
132 /* and wake up one possible exclusive waiter */
133 wake_up(&queue->receive_queue);
134 }
135
_mali_osk_notification_queue_dequeue(_mali_osk_notification_queue_t * queue,_mali_osk_notification_t ** result)136 _mali_osk_errcode_t _mali_osk_notification_queue_dequeue(_mali_osk_notification_queue_t *queue, _mali_osk_notification_t **result)
137 {
138 #if defined(MALI_UPPER_HALF_SCHEDULING)
139 unsigned long irq_flags;
140 #endif
141
142 _mali_osk_errcode_t ret = _MALI_OSK_ERR_ITEM_NOT_FOUND;
143 _mali_osk_notification_wrapper_t *wrapper_object;
144
145 #if defined(MALI_UPPER_HALF_SCHEDULING)
146 spin_lock_irqsave(&queue->mutex, irq_flags);
147 #else
148 spin_lock(&queue->mutex);
149 #endif
150
151 if (!list_empty(&queue->head)) {
152 wrapper_object = list_entry(queue->head.next, _mali_osk_notification_wrapper_t, list);
153 *result = &(wrapper_object->data);
154 list_del_init(&wrapper_object->list);
155 ret = _MALI_OSK_ERR_OK;
156 }
157
158 #if defined(MALI_UPPER_HALF_SCHEDULING)
159 spin_unlock_irqrestore(&queue->mutex, irq_flags);
160 #else
161 spin_unlock(&queue->mutex);
162 #endif
163
164 return ret;
165 }
166
_mali_osk_notification_queue_receive(_mali_osk_notification_queue_t * queue,_mali_osk_notification_t ** result)167 _mali_osk_errcode_t _mali_osk_notification_queue_receive(_mali_osk_notification_queue_t *queue, _mali_osk_notification_t **result)
168 {
169 /* check input */
170 MALI_DEBUG_ASSERT_POINTER(queue);
171 MALI_DEBUG_ASSERT_POINTER(result);
172
173 /* default result */
174 *result = NULL;
175
176 if (wait_event_interruptible(queue->receive_queue,
177 _MALI_OSK_ERR_OK == _mali_osk_notification_queue_dequeue(queue, result))) {
178 return _MALI_OSK_ERR_RESTARTSYSCALL;
179 }
180
181 return _MALI_OSK_ERR_OK; /* all ok */
182 }
183