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1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/slab.h>
3#include <linux/kernel.h>
4#include <linux/module.h>
5#include <linux/device.h>
6#include <linux/workqueue.h>
7#include <linux/kfifo.h>
8#include <linux/mutex.h>
9#include <linux/iio/iio.h>
10#include <linux/iio/buffer.h>
11#include <linux/iio/kfifo_buf.h>
12#include <linux/iio/buffer_impl.h>
13#include <linux/sched.h>
14#include <linux/poll.h>
15
16struct iio_kfifo {
17 struct iio_buffer buffer;
18 struct kfifo kf;
19 struct mutex user_lock;
20 int update_needed;
21};
22
23#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
24
25static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
26 size_t bytes_per_datum, unsigned int length)
27{
28 if ((length == 0) || (bytes_per_datum == 0))
29 return -EINVAL;
30
31 /*
32 * Make sure we don't overflow an unsigned int after kfifo rounds up to
33 * the next power of 2.
34 */
35 if (roundup_pow_of_two(length) > UINT_MAX / bytes_per_datum)
36 return -EINVAL;
37
38 return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
39 bytes_per_datum, GFP_KERNEL);
40}
41
42static int iio_request_update_kfifo(struct iio_buffer *r)
43{
44 int ret = 0;
45 struct iio_kfifo *buf = iio_to_kfifo(r);
46
47 mutex_lock(&buf->user_lock);
48 if (buf->update_needed) {
49 kfifo_free(&buf->kf);
50 ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
51 buf->buffer.length);
52 if (ret >= 0)
53 buf->update_needed = false;
54 } else {
55 kfifo_reset_out(&buf->kf);
56 }
57 mutex_unlock(&buf->user_lock);
58
59 return ret;
60}
61
62static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
63{
64 struct iio_kfifo *kf = iio_to_kfifo(r);
65 kf->update_needed = true;
66 return 0;
67}
68
69static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
70{
71 if (r->bytes_per_datum != bpd) {
72 r->bytes_per_datum = bpd;
73 iio_mark_update_needed_kfifo(r);
74 }
75 return 0;
76}
77
78static int iio_set_length_kfifo(struct iio_buffer *r, unsigned int length)
79{
80 /* Avoid an invalid state */
81 if (length < 2)
82 length = 2;
83 if (r->length != length) {
84 r->length = length;
85 iio_mark_update_needed_kfifo(r);
86 }
87 return 0;
88}
89
90static int iio_store_to_kfifo(struct iio_buffer *r,
91 const void *data)
92{
93 int ret;
94 struct iio_kfifo *kf = iio_to_kfifo(r);
95 ret = kfifo_in(&kf->kf, data, 1);
96 if (ret != 1)
97 return -EBUSY;
98 return 0;
99}
100
101static int iio_read_first_n_kfifo(struct iio_buffer *r,
102 size_t n, char __user *buf)
103{
104 int ret, copied;
105 struct iio_kfifo *kf = iio_to_kfifo(r);
106
107 if (mutex_lock_interruptible(&kf->user_lock))
108 return -ERESTARTSYS;
109
110 if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
111 ret = -EINVAL;
112 else
113 ret = kfifo_to_user(&kf->kf, buf, n, &copied);
114 mutex_unlock(&kf->user_lock);
115 if (ret < 0)
116 return ret;
117
118 return copied;
119}
120
121static size_t iio_kfifo_buf_data_available(struct iio_buffer *r)
122{
123 struct iio_kfifo *kf = iio_to_kfifo(r);
124 size_t samples;
125
126 mutex_lock(&kf->user_lock);
127 samples = kfifo_len(&kf->kf);
128 mutex_unlock(&kf->user_lock);
129
130 return samples;
131}
132
133static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
134{
135 struct iio_kfifo *kf = iio_to_kfifo(buffer);
136
137 mutex_destroy(&kf->user_lock);
138 kfifo_free(&kf->kf);
139 kfree(kf);
140}
141
142static const struct iio_buffer_access_funcs kfifo_access_funcs = {
143 .store_to = &iio_store_to_kfifo,
144 .read_first_n = &iio_read_first_n_kfifo,
145 .data_available = iio_kfifo_buf_data_available,
146 .request_update = &iio_request_update_kfifo,
147 .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
148 .set_length = &iio_set_length_kfifo,
149 .release = &iio_kfifo_buffer_release,
150
151 .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
152};
153
154struct iio_buffer *iio_kfifo_allocate(void)
155{
156 struct iio_kfifo *kf;
157
158 kf = kzalloc(sizeof(*kf), GFP_KERNEL);
159 if (!kf)
160 return NULL;
161
162 kf->update_needed = true;
163 iio_buffer_init(&kf->buffer);
164 kf->buffer.access = &kfifo_access_funcs;
165 kf->buffer.length = 2;
166 mutex_init(&kf->user_lock);
167
168 return &kf->buffer;
169}
170EXPORT_SYMBOL(iio_kfifo_allocate);
171
172void iio_kfifo_free(struct iio_buffer *r)
173{
174 iio_buffer_put(r);
175}
176EXPORT_SYMBOL(iio_kfifo_free);
177
178static void devm_iio_kfifo_release(struct device *dev, void *res)
179{
180 iio_kfifo_free(*(struct iio_buffer **)res);
181}
182
183static int devm_iio_kfifo_match(struct device *dev, void *res, void *data)
184{
185 struct iio_buffer **r = res;
186
187 if (WARN_ON(!r || !*r))
188 return 0;
189
190 return *r == data;
191}
192
193/**
194 * devm_iio_fifo_allocate - Resource-managed iio_kfifo_allocate()
195 * @dev: Device to allocate kfifo buffer for
196 *
197 * RETURNS:
198 * Pointer to allocated iio_buffer on success, NULL on failure.
199 */
200struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
201{
202 struct iio_buffer **ptr, *r;
203
204 ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
205 if (!ptr)
206 return NULL;
207
208 r = iio_kfifo_allocate();
209 if (r) {
210 *ptr = r;
211 devres_add(dev, ptr);
212 } else {
213 devres_free(ptr);
214 }
215
216 return r;
217}
218EXPORT_SYMBOL(devm_iio_kfifo_allocate);
219
220/**
221 * devm_iio_fifo_free - Resource-managed iio_kfifo_free()
222 * @dev: Device the buffer belongs to
223 * @r: The buffer associated with the device
224 */
225void devm_iio_kfifo_free(struct device *dev, struct iio_buffer *r)
226{
227 WARN_ON(devres_release(dev, devm_iio_kfifo_release,
228 devm_iio_kfifo_match, r));
229}
230EXPORT_SYMBOL(devm_iio_kfifo_free);
231
232MODULE_LICENSE("GPL");
1#include <linux/slab.h>
2#include <linux/kernel.h>
3#include <linux/module.h>
4#include <linux/device.h>
5#include <linux/workqueue.h>
6#include <linux/kfifo.h>
7#include <linux/mutex.h>
8#include <linux/iio/kfifo_buf.h>
9#include <linux/sched.h>
10#include <linux/poll.h>
11
12struct iio_kfifo {
13 struct iio_buffer buffer;
14 struct kfifo kf;
15 struct mutex user_lock;
16 int update_needed;
17};
18
19#define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer)
20
21static inline int __iio_allocate_kfifo(struct iio_kfifo *buf,
22 int bytes_per_datum, int length)
23{
24 if ((length == 0) || (bytes_per_datum == 0))
25 return -EINVAL;
26
27 return __kfifo_alloc((struct __kfifo *)&buf->kf, length,
28 bytes_per_datum, GFP_KERNEL);
29}
30
31static int iio_request_update_kfifo(struct iio_buffer *r)
32{
33 int ret = 0;
34 struct iio_kfifo *buf = iio_to_kfifo(r);
35
36 mutex_lock(&buf->user_lock);
37 if (buf->update_needed) {
38 kfifo_free(&buf->kf);
39 ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum,
40 buf->buffer.length);
41 if (ret >= 0)
42 buf->update_needed = false;
43 } else {
44 kfifo_reset_out(&buf->kf);
45 }
46 mutex_unlock(&buf->user_lock);
47
48 return ret;
49}
50
51static int iio_mark_update_needed_kfifo(struct iio_buffer *r)
52{
53 struct iio_kfifo *kf = iio_to_kfifo(r);
54 kf->update_needed = true;
55 return 0;
56}
57
58static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd)
59{
60 if (r->bytes_per_datum != bpd) {
61 r->bytes_per_datum = bpd;
62 iio_mark_update_needed_kfifo(r);
63 }
64 return 0;
65}
66
67static int iio_set_length_kfifo(struct iio_buffer *r, int length)
68{
69 /* Avoid an invalid state */
70 if (length < 2)
71 length = 2;
72 if (r->length != length) {
73 r->length = length;
74 iio_mark_update_needed_kfifo(r);
75 }
76 return 0;
77}
78
79static int iio_store_to_kfifo(struct iio_buffer *r,
80 const void *data)
81{
82 int ret;
83 struct iio_kfifo *kf = iio_to_kfifo(r);
84 ret = kfifo_in(&kf->kf, data, 1);
85 if (ret != 1)
86 return -EBUSY;
87 return 0;
88}
89
90static int iio_read_first_n_kfifo(struct iio_buffer *r,
91 size_t n, char __user *buf)
92{
93 int ret, copied;
94 struct iio_kfifo *kf = iio_to_kfifo(r);
95
96 if (mutex_lock_interruptible(&kf->user_lock))
97 return -ERESTARTSYS;
98
99 if (!kfifo_initialized(&kf->kf) || n < kfifo_esize(&kf->kf))
100 ret = -EINVAL;
101 else
102 ret = kfifo_to_user(&kf->kf, buf, n, &copied);
103 mutex_unlock(&kf->user_lock);
104 if (ret < 0)
105 return ret;
106
107 return copied;
108}
109
110static size_t iio_kfifo_buf_data_available(struct iio_buffer *r)
111{
112 struct iio_kfifo *kf = iio_to_kfifo(r);
113 size_t samples;
114
115 mutex_lock(&kf->user_lock);
116 samples = kfifo_len(&kf->kf);
117 mutex_unlock(&kf->user_lock);
118
119 return samples;
120}
121
122static void iio_kfifo_buffer_release(struct iio_buffer *buffer)
123{
124 struct iio_kfifo *kf = iio_to_kfifo(buffer);
125
126 mutex_destroy(&kf->user_lock);
127 kfifo_free(&kf->kf);
128 kfree(kf);
129}
130
131static const struct iio_buffer_access_funcs kfifo_access_funcs = {
132 .store_to = &iio_store_to_kfifo,
133 .read_first_n = &iio_read_first_n_kfifo,
134 .data_available = iio_kfifo_buf_data_available,
135 .request_update = &iio_request_update_kfifo,
136 .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo,
137 .set_length = &iio_set_length_kfifo,
138 .release = &iio_kfifo_buffer_release,
139
140 .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED,
141};
142
143struct iio_buffer *iio_kfifo_allocate(void)
144{
145 struct iio_kfifo *kf;
146
147 kf = kzalloc(sizeof(*kf), GFP_KERNEL);
148 if (!kf)
149 return NULL;
150
151 kf->update_needed = true;
152 iio_buffer_init(&kf->buffer);
153 kf->buffer.access = &kfifo_access_funcs;
154 kf->buffer.length = 2;
155 mutex_init(&kf->user_lock);
156
157 return &kf->buffer;
158}
159EXPORT_SYMBOL(iio_kfifo_allocate);
160
161void iio_kfifo_free(struct iio_buffer *r)
162{
163 iio_buffer_put(r);
164}
165EXPORT_SYMBOL(iio_kfifo_free);
166
167static void devm_iio_kfifo_release(struct device *dev, void *res)
168{
169 iio_kfifo_free(*(struct iio_buffer **)res);
170}
171
172static int devm_iio_kfifo_match(struct device *dev, void *res, void *data)
173{
174 struct iio_buffer **r = res;
175
176 if (WARN_ON(!r || !*r))
177 return 0;
178
179 return *r == data;
180}
181
182/**
183 * devm_iio_fifo_allocate - Resource-managed iio_kfifo_allocate()
184 * @dev: Device to allocate kfifo buffer for
185 *
186 * RETURNS:
187 * Pointer to allocated iio_buffer on success, NULL on failure.
188 */
189struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
190{
191 struct iio_buffer **ptr, *r;
192
193 ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
194 if (!ptr)
195 return NULL;
196
197 r = iio_kfifo_allocate();
198 if (r) {
199 *ptr = r;
200 devres_add(dev, ptr);
201 } else {
202 devres_free(ptr);
203 }
204
205 return r;
206}
207EXPORT_SYMBOL(devm_iio_kfifo_allocate);
208
209/**
210 * devm_iio_fifo_free - Resource-managed iio_kfifo_free()
211 * @dev: Device the buffer belongs to
212 * @r: The buffer associated with the device
213 */
214void devm_iio_kfifo_free(struct device *dev, struct iio_buffer *r)
215{
216 WARN_ON(devres_release(dev, devm_iio_kfifo_release,
217 devm_iio_kfifo_match, r));
218}
219EXPORT_SYMBOL(devm_iio_kfifo_free);
220
221MODULE_LICENSE("GPL");