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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
b174baf4 JC |
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> | |
19a5a8a5 | 9 | #include <linux/iio/iio.h> |
8abd5ba5 | 10 | #include <linux/iio/buffer.h> |
06458e27 | 11 | #include <linux/iio/kfifo_buf.h> |
33dd94cb | 12 | #include <linux/iio/buffer_impl.h> |
7c388ec1 | 13 | #include <linux/sched.h> |
623c334c | 14 | #include <linux/poll.h> |
b174baf4 | 15 | |
a710cc77 | 16 | struct iio_kfifo { |
14555b14 | 17 | struct iio_buffer buffer; |
a710cc77 | 18 | struct kfifo kf; |
0894d80d | 19 | struct mutex user_lock; |
a710cc77 | 20 | int update_needed; |
a710cc77 JC |
21 | }; |
22 | ||
14555b14 | 23 | #define iio_to_kfifo(r) container_of(r, struct iio_kfifo, buffer) |
5565a450 | 24 | |
b174baf4 | 25 | static inline int __iio_allocate_kfifo(struct iio_kfifo *buf, |
c043ec1c | 26 | size_t bytes_per_datum, unsigned int length) |
b174baf4 JC |
27 | { |
28 | if ((length == 0) || (bytes_per_datum == 0)) | |
29 | return -EINVAL; | |
30 | ||
3d13de4b MK |
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 | ||
c559afbf JC |
38 | return __kfifo_alloc((struct __kfifo *)&buf->kf, length, |
39 | bytes_per_datum, GFP_KERNEL); | |
b174baf4 JC |
40 | } |
41 | ||
14555b14 | 42 | static int iio_request_update_kfifo(struct iio_buffer *r) |
b174baf4 JC |
43 | { |
44 | int ret = 0; | |
45 | struct iio_kfifo *buf = iio_to_kfifo(r); | |
46 | ||
0894d80d | 47 | mutex_lock(&buf->user_lock); |
5b78e513 LPC |
48 | if (buf->update_needed) { |
49 | kfifo_free(&buf->kf); | |
50 | ret = __iio_allocate_kfifo(buf, buf->buffer.bytes_per_datum, | |
14555b14 | 51 | buf->buffer.length); |
e5f1efb9 GM |
52 | if (ret >= 0) |
53 | buf->update_needed = false; | |
5b78e513 LPC |
54 | } else { |
55 | kfifo_reset_out(&buf->kf); | |
56 | } | |
0894d80d | 57 | mutex_unlock(&buf->user_lock); |
5b78e513 | 58 | |
b174baf4 JC |
59 | return ret; |
60 | } | |
b174baf4 | 61 | |
869871b5 | 62 | static int iio_mark_update_needed_kfifo(struct iio_buffer *r) |
b174baf4 | 63 | { |
869871b5 LPC |
64 | struct iio_kfifo *kf = iio_to_kfifo(r); |
65 | kf->update_needed = true; | |
b174baf4 JC |
66 | return 0; |
67 | } | |
b174baf4 | 68 | |
869871b5 | 69 | static int iio_set_bytes_per_datum_kfifo(struct iio_buffer *r, size_t bpd) |
b174baf4 | 70 | { |
869871b5 LPC |
71 | if (r->bytes_per_datum != bpd) { |
72 | r->bytes_per_datum = bpd; | |
73 | iio_mark_update_needed_kfifo(r); | |
74 | } | |
b174baf4 JC |
75 | return 0; |
76 | } | |
b174baf4 | 77 | |
c043ec1c | 78 | static int iio_set_length_kfifo(struct iio_buffer *r, unsigned int length) |
b174baf4 | 79 | { |
7c388ec1 JC |
80 | /* Avoid an invalid state */ |
81 | if (length < 2) | |
82 | length = 2; | |
b174baf4 JC |
83 | if (r->length != length) { |
84 | r->length = length; | |
869871b5 | 85 | iio_mark_update_needed_kfifo(r); |
b174baf4 JC |
86 | } |
87 | return 0; | |
88 | } | |
b174baf4 | 89 | |
14555b14 | 90 | static int iio_store_to_kfifo(struct iio_buffer *r, |
5d65d920 | 91 | const void *data) |
b174baf4 JC |
92 | { |
93 | int ret; | |
94 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
c559afbf JC |
95 | ret = kfifo_in(&kf->kf, data, 1); |
96 | if (ret != 1) | |
b174baf4 | 97 | return -EBUSY; |
b174baf4 JC |
98 | return 0; |
99 | } | |
b174baf4 | 100 | |
14555b14 | 101 | static int iio_read_first_n_kfifo(struct iio_buffer *r, |
b26a2188 | 102 | size_t n, char __user *buf) |
b174baf4 JC |
103 | { |
104 | int ret, copied; | |
105 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
106 | ||
0894d80d LPC |
107 | if (mutex_lock_interruptible(&kf->user_lock)) |
108 | return -ERESTARTSYS; | |
8fe64955 | 109 | |
0894d80d LPC |
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); | |
0894d80d LPC |
114 | mutex_unlock(&kf->user_lock); |
115 | if (ret < 0) | |
116 | return ret; | |
117 | ||
b174baf4 JC |
118 | return copied; |
119 | } | |
5565a450 | 120 | |
37d34556 | 121 | static size_t iio_kfifo_buf_data_available(struct iio_buffer *r) |
355c1a14 LPC |
122 | { |
123 | struct iio_kfifo *kf = iio_to_kfifo(r); | |
37d34556 | 124 | size_t samples; |
355c1a14 LPC |
125 | |
126 | mutex_lock(&kf->user_lock); | |
37d34556 | 127 | samples = kfifo_len(&kf->kf); |
355c1a14 LPC |
128 | mutex_unlock(&kf->user_lock); |
129 | ||
37d34556 | 130 | return samples; |
355c1a14 LPC |
131 | } |
132 | ||
9e69c935 LPC |
133 | static void iio_kfifo_buffer_release(struct iio_buffer *buffer) |
134 | { | |
f6c23f48 LPC |
135 | struct iio_kfifo *kf = iio_to_kfifo(buffer); |
136 | ||
0894d80d | 137 | mutex_destroy(&kf->user_lock); |
f6c23f48 LPC |
138 | kfifo_free(&kf->kf); |
139 | kfree(kf); | |
9e69c935 LPC |
140 | } |
141 | ||
7e632344 | 142 | static const struct iio_buffer_access_funcs kfifo_access_funcs = { |
5565a450 JC |
143 | .store_to = &iio_store_to_kfifo, |
144 | .read_first_n = &iio_read_first_n_kfifo, | |
355c1a14 | 145 | .data_available = iio_kfifo_buf_data_available, |
5565a450 | 146 | .request_update = &iio_request_update_kfifo, |
5565a450 | 147 | .set_bytes_per_datum = &iio_set_bytes_per_datum_kfifo, |
5565a450 | 148 | .set_length = &iio_set_length_kfifo, |
9e69c935 | 149 | .release = &iio_kfifo_buffer_release, |
225d59ad LPC |
150 | |
151 | .modes = INDIO_BUFFER_SOFTWARE | INDIO_BUFFER_TRIGGERED, | |
5565a450 | 152 | }; |
7e632344 | 153 | |
7ab374a0 | 154 | struct iio_buffer *iio_kfifo_allocate(void) |
7e632344 LPC |
155 | { |
156 | struct iio_kfifo *kf; | |
157 | ||
7ab374a0 | 158 | kf = kzalloc(sizeof(*kf), GFP_KERNEL); |
7e632344 LPC |
159 | if (!kf) |
160 | return NULL; | |
7ab374a0 | 161 | |
7e632344 LPC |
162 | kf->update_needed = true; |
163 | iio_buffer_init(&kf->buffer); | |
7e632344 | 164 | kf->buffer.access = &kfifo_access_funcs; |
7c388ec1 | 165 | kf->buffer.length = 2; |
0894d80d | 166 | mutex_init(&kf->user_lock); |
7ab374a0 | 167 | |
7e632344 LPC |
168 | return &kf->buffer; |
169 | } | |
170 | EXPORT_SYMBOL(iio_kfifo_allocate); | |
171 | ||
172 | void iio_kfifo_free(struct iio_buffer *r) | |
173 | { | |
9e69c935 | 174 | iio_buffer_put(r); |
7e632344 LPC |
175 | } |
176 | EXPORT_SYMBOL(iio_kfifo_free); | |
5565a450 | 177 | |
780103fe KW |
178 | static void devm_iio_kfifo_release(struct device *dev, void *res) |
179 | { | |
180 | iio_kfifo_free(*(struct iio_buffer **)res); | |
181 | } | |
182 | ||
183 | static 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 | */ | |
200 | struct 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 | } | |
218 | EXPORT_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 | */ | |
225 | void 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 | } | |
230 | EXPORT_SYMBOL(devm_iio_kfifo_free); | |
231 | ||
b174baf4 | 232 | MODULE_LICENSE("GPL"); |