drivers/rpmsg/qcom_glink_smem.c

   1 /*
   2  * Copyright (c) 2016, Linaro Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/io.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/mfd/syscon.h>
  21 #include <linux/slab.h>
  22 #include <linux/rpmsg.h>
  23 #include <linux/idr.h>
  24 #include <linux/circ_buf.h>
  25 #include <linux/soc/qcom/smem.h>
  26 #include <linux/sizes.h>
  27 #include <linux/delay.h>
  28 #include <linux/regmap.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/list.h>
  31
  32 #include <linux/rpmsg/qcom_glink.h>
  33
  34 #include "qcom_glink_native.h"
  35
  36 #define FIFO_FULL_RESERVE 8
  37 #define FIFO_ALIGNMENT 8
  38 #define TX_BLOCKED_CMD_RESERVE 8 /* size of struct read_notif_request */
  39
  40 #define SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR       478
  41 #define SMEM_GLINK_NATIVE_XPRT_FIFO_0           479
  42 #define SMEM_GLINK_NATIVE_XPRT_FIFO_1           480
  43
  44 struct glink_smem_pipe {
  45         struct qcom_glink_pipe native;
  46
  47         __le32 *tail;
  48         __le32 *head;
  49
  50         void *fifo;
  51
  52         int remote_pid;
  53 };
  54
  55 #define to_smem_pipe(p) container_of(p, struct glink_smem_pipe, native)
  56
  57 static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
  58 {
  59         struct glink_smem_pipe *pipe = to_smem_pipe(np);
  60         size_t len;
  61         void *fifo;
  62         u32 head;
  63         u32 tail;
  64
  65         if (!pipe->fifo) {
  66                 fifo = qcom_smem_get(pipe->remote_pid,
  67                                      SMEM_GLINK_NATIVE_XPRT_FIFO_1, &len);
  68                 if (IS_ERR(fifo)) {
  69                         pr_err("failed to acquire RX fifo handle: %ld\n",
  70                                PTR_ERR(fifo));
  71                         return 0;
  72                 }
  73
  74                 pipe->fifo = fifo;
  75                 pipe->native.length = len;
  76         }
  77
  78         head = le32_to_cpu(*pipe->head);
  79         tail = le32_to_cpu(*pipe->tail);
  80
  81         if (head < tail)
  82                 return pipe->native.length - tail + head;
  83         else
  84                 return head - tail;
  85 }
  86
  87 static void glink_smem_rx_peak(struct qcom_glink_pipe *np,
  88                                void *data, unsigned int offset, size_t count)
  89 {
  90         struct glink_smem_pipe *pipe = to_smem_pipe(np);
  91         size_t len;
  92         u32 tail;
  93
  94         tail = le32_to_cpu(*pipe->tail);
  95         tail += offset;
  96         if (tail >= pipe->native.length)
  97                 tail -= pipe->native.length;
  98
  99         len = min_t(size_t, count, pipe->native.length - tail);
 100         if (len) {
 101                 __ioread32_copy(data, pipe->fifo + tail,
 102                                 len / sizeof(u32));
 103         }
 104
 105         if (len != count) {
 106                 __ioread32_copy(data + len, pipe->fifo,
 107                                 (count - len) / sizeof(u32));
 108         }
 109 }
 110
 111 static void glink_smem_rx_advance(struct qcom_glink_pipe *np,
 112                                   size_t count)
 113 {
 114         struct glink_smem_pipe *pipe = to_smem_pipe(np);
 115         u32 tail;
 116
 117         tail = le32_to_cpu(*pipe->tail);
 118
 119         tail += count;
 120         if (tail > pipe->native.length)
 121                 tail -= pipe->native.length;
 122
 123         *pipe->tail = cpu_to_le32(tail);
 124 }
 125
 126 static size_t glink_smem_tx_avail(struct qcom_glink_pipe *np)
 127 {
 128         struct glink_smem_pipe *pipe = to_smem_pipe(np);
 129         u32 head;
 130         u32 tail;
 131         u32 avail;
 132
 133         head = le32_to_cpu(*pipe->head);
 134         tail = le32_to_cpu(*pipe->tail);
 135
 136         if (tail <= head)
 137                 avail = pipe->native.length - head + tail;
 138         else
 139                 avail = tail - head;
 140
 141         if (avail < (FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE))
 142                 avail = 0;
 143         else
 144                 avail -= FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE;
 145
 146         return avail;
 147 }
 148
 149 static unsigned int glink_smem_tx_write_one(struct glink_smem_pipe *pipe,
 150                                             unsigned int head,
 151                                             const void *data, size_t count)
 152 {
 153         size_t len;
 154
 155         len = min_t(size_t, count, pipe->native.length - head);
 156         if (len)
 157                 memcpy(pipe->fifo + head, data, len);
 158
 159         if (len != count)
 160                 memcpy(pipe->fifo, data + len, count - len);
 161
 162         head += count;
 163         if (head >= pipe->native.length)
 164                 head -= pipe->native.length;
 165
 166         return head;
 167 }
 168
 169 static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
 170                                 const void *hdr, size_t hlen,
 171                                 const void *data, size_t dlen)
 172 {
 173         struct glink_smem_pipe *pipe = to_smem_pipe(glink_pipe);
 174         unsigned int head;
 175
 176         head = le32_to_cpu(*pipe->head);
 177
 178         head = glink_smem_tx_write_one(pipe, head, hdr, hlen);
 179         head = glink_smem_tx_write_one(pipe, head, data, dlen);
 180
 181         /* Ensure head is always aligned to 8 bytes */
 182         head = ALIGN(head, 8);
 183         if (head >= pipe->native.length)
 184                 head -= pipe->native.length;
 185
 186         /* Ensure ordering of fifo and head update */
 187         wmb();
 188
 189         *pipe->head = cpu_to_le32(head);
 190 }
 191
 192 static void qcom_glink_smem_release(struct device *dev)
 193 {
 194         kfree(dev);
 195 }
 196
 197 struct qcom_glink *qcom_glink_smem_register(struct device *parent,
 198                                             struct device_node *node)
 199 {
 200         struct glink_smem_pipe *rx_pipe;
 201         struct glink_smem_pipe *tx_pipe;
 202         struct qcom_glink *glink;
 203         struct device *dev;
 204         u32 remote_pid;
 205         __le32 *descs;
 206         size_t size;
 207         int ret;
 208
 209         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 210         if (!dev)
 211                 return ERR_PTR(-ENOMEM);
 212
 213         dev->parent = parent;
 214         dev->of_node = node;
 215         dev->release = qcom_glink_smem_release;
 216         dev_set_name(dev, "%s:%s", node->parent->name, node->name);
 217         ret = device_register(dev);
 218         if (ret) {
 219                 pr_err("failed to register glink edge\n");
 220                 return ERR_PTR(ret);
 221         }
 222
 223         ret = of_property_read_u32(dev->of_node, "qcom,remote-pid",
 224                                    &remote_pid);
 225         if (ret) {
 226                 dev_err(dev, "failed to parse qcom,remote-pid\n");
 227                 goto err_put_dev;
 228         }
 229
 230         rx_pipe = devm_kzalloc(dev, sizeof(*rx_pipe), GFP_KERNEL);
 231         tx_pipe = devm_kzalloc(dev, sizeof(*tx_pipe), GFP_KERNEL);
 232         if (!rx_pipe || !tx_pipe) {
 233                 ret = -ENOMEM;
 234                 goto err_put_dev;
 235         }
 236
 237         ret = qcom_smem_alloc(remote_pid,
 238                               SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, 32);
 239         if (ret && ret != -EEXIST) {
 240                 dev_err(dev, "failed to allocate glink descriptors\n");
 241                 goto err_put_dev;
 242         }
 243
 244         descs = qcom_smem_get(remote_pid,
 245                               SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, &size);
 246         if (IS_ERR(descs)) {
 247                 dev_err(dev, "failed to acquire xprt descriptor\n");
 248                 ret = PTR_ERR(descs);
 249                 goto err_put_dev;
 250         }
 251
 252         if (size != 32) {
 253                 dev_err(dev, "glink descriptor of invalid size\n");
 254                 ret = -EINVAL;
 255                 goto err_put_dev;
 256         }
 257
 258         tx_pipe->tail = &descs[0];
 259         tx_pipe->head = &descs[1];
 260         rx_pipe->tail = &descs[2];
 261         rx_pipe->head = &descs[3];
 262
 263         ret = qcom_smem_alloc(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
 264                               SZ_16K);
 265         if (ret && ret != -EEXIST) {
 266                 dev_err(dev, "failed to allocate TX fifo\n");
 267                 goto err_put_dev;
 268         }
 269
 270         tx_pipe->fifo = qcom_smem_get(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
 271                                       &tx_pipe->native.length);
 272         if (IS_ERR(tx_pipe->fifo)) {
 273                 dev_err(dev, "failed to acquire TX fifo\n");
 274                 ret = PTR_ERR(tx_pipe->fifo);
 275                 goto err_put_dev;
 276         }
 277
 278         rx_pipe->native.avail = glink_smem_rx_avail;
 279         rx_pipe->native.peak = glink_smem_rx_peak;
 280         rx_pipe->native.advance = glink_smem_rx_advance;
 281         rx_pipe->remote_pid = remote_pid;
 282
 283         tx_pipe->native.avail = glink_smem_tx_avail;
 284         tx_pipe->native.write = glink_smem_tx_write;
 285         tx_pipe->remote_pid = remote_pid;
 286
 287         *rx_pipe->tail = 0;
 288         *tx_pipe->head = 0;
 289
 290         glink = qcom_glink_native_probe(dev,
 291                                         GLINK_FEATURE_INTENT_REUSE,
 292                                         &rx_pipe->native, &tx_pipe->native,
 293                                         false);
 294         if (IS_ERR(glink)) {
 295                 ret = PTR_ERR(glink);
 296                 goto err_put_dev;
 297         }
 298
 299         return glink;
 300
 301 err_put_dev:
 302         put_device(dev);
 303
 304         return ERR_PTR(ret);
 305 }
 306 EXPORT_SYMBOL_GPL(qcom_glink_smem_register);
 307
 308 void qcom_glink_smem_unregister(struct qcom_glink *glink)
 309 {
 310         qcom_glink_native_remove(glink);
 311         qcom_glink_native_unregister(glink);
 312 }
 313 EXPORT_SYMBOL_GPL(qcom_glink_smem_unregister);
 314
 315 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
 316 MODULE_DESCRIPTION("Qualcomm GLINK SMEM driver");
 317 MODULE_LICENSE("GPL v2");