drivers/rpmsg/qcom_glink_smem.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016, Linaro Ltd
   4  */
   5
   6 #include <linux/io.h>
   7 #include <linux/module.h>
   8 #include <linux/of.h>
   9 #include <linux/of_address.h>
  10 #include <linux/of_irq.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/platform_device.h>
  13 #include <linux/mailbox_client.h>
  14 #include <linux/mfd/syscon.h>
  15 #include <linux/slab.h>
  16 #include <linux/rpmsg.h>
  17 #include <linux/idr.h>
  18 #include <linux/circ_buf.h>
  19 #include <linux/soc/qcom/smem.h>
  20 #include <linux/sizes.h>
  21 #include <linux/delay.h>
  22 #include <linux/regmap.h>
  23 #include <linux/workqueue.h>
  24 #include <linux/list.h>
  25
  26 #include <linux/rpmsg/qcom_glink.h>
  27
  28 #include "qcom_glink_native.h"
  29
  30 #define FIFO_FULL_RESERVE 8
  31 #define FIFO_ALIGNMENT 8
  32 #define TX_BLOCKED_CMD_RESERVE 8 /* size of struct read_notif_request */
  33
  34 #define SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR       478
  35 #define SMEM_GLINK_NATIVE_XPRT_FIFO_0           479
  36 #define SMEM_GLINK_NATIVE_XPRT_FIFO_1           480
  37
  38 struct qcom_glink_smem {
  39         struct device dev;
  40
  41         int irq;
  42         struct qcom_glink *glink;
  43
  44         struct mbox_client mbox_client;
  45         struct mbox_chan *mbox_chan;
  46
  47         u32 remote_pid;
  48 };
  49
  50 struct glink_smem_pipe {
  51         struct qcom_glink_pipe native;
  52
  53         __le32 *tail;
  54         __le32 *head;
  55
  56         void *fifo;
  57
  58         struct qcom_glink_smem *smem;
  59 };
  60
  61 #define to_smem_pipe(p) container_of(p, struct glink_smem_pipe, native)
  62
  63 static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
  64 {
  65         struct glink_smem_pipe *pipe = to_smem_pipe(np);
  66         struct qcom_glink_smem *smem = pipe->smem;
  67         size_t len;
  68         void *fifo;
  69         u32 head;
  70         u32 tail;
  71
  72         if (!pipe->fifo) {
  73                 fifo = qcom_smem_get(smem->remote_pid,
  74                                      SMEM_GLINK_NATIVE_XPRT_FIFO_1, &len);
  75                 if (IS_ERR(fifo)) {
  76                         pr_err("failed to acquire RX fifo handle: %ld\n",
  77                                PTR_ERR(fifo));
  78                         return 0;
  79                 }
  80
  81                 pipe->fifo = fifo;
  82                 pipe->native.length = len;
  83         }
  84
  85         head = le32_to_cpu(*pipe->head);
  86         tail = le32_to_cpu(*pipe->tail);
  87
  88         if (head < tail)
  89                 return pipe->native.length - tail + head;
  90         else
  91                 return head - tail;
  92 }
  93
  94 static void glink_smem_rx_peek(struct qcom_glink_pipe *np,
  95                                void *data, unsigned int offset, size_t count)
  96 {
  97         struct glink_smem_pipe *pipe = to_smem_pipe(np);
  98         size_t len;
  99         u32 tail;
 100
 101         tail = le32_to_cpu(*pipe->tail);
 102         tail += offset;
 103         if (tail >= pipe->native.length)
 104                 tail -= pipe->native.length;
 105
 106         len = min_t(size_t, count, pipe->native.length - tail);
 107         if (len)
 108                 memcpy_fromio(data, pipe->fifo + tail, len);
 109
 110         if (len != count)
 111                 memcpy_fromio(data + len, pipe->fifo, (count - len));
 112 }
 113
 114 static void glink_smem_rx_advance(struct qcom_glink_pipe *np,
 115                                   size_t count)
 116 {
 117         struct glink_smem_pipe *pipe = to_smem_pipe(np);
 118         u32 tail;
 119
 120         tail = le32_to_cpu(*pipe->tail);
 121
 122         tail += count;
 123         if (tail >= pipe->native.length)
 124                 tail -= pipe->native.length;
 125
 126         *pipe->tail = cpu_to_le32(tail);
 127 }
 128
 129 static size_t glink_smem_tx_avail(struct qcom_glink_pipe *np)
 130 {
 131         struct glink_smem_pipe *pipe = to_smem_pipe(np);
 132         u32 head;
 133         u32 tail;
 134         u32 avail;
 135
 136         head = le32_to_cpu(*pipe->head);
 137         tail = le32_to_cpu(*pipe->tail);
 138
 139         if (tail <= head)
 140                 avail = pipe->native.length - head + tail;
 141         else
 142                 avail = tail - head;
 143
 144         if (avail < (FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE))
 145                 avail = 0;
 146         else
 147                 avail -= FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE;
 148
 149         return avail;
 150 }
 151
 152 static unsigned int glink_smem_tx_write_one(struct glink_smem_pipe *pipe,
 153                                             unsigned int head,
 154                                             const void *data, size_t count)
 155 {
 156         size_t len;
 157
 158         len = min_t(size_t, count, pipe->native.length - head);
 159         if (len)
 160                 memcpy(pipe->fifo + head, data, len);
 161
 162         if (len != count)
 163                 memcpy(pipe->fifo, data + len, count - len);
 164
 165         head += count;
 166         if (head >= pipe->native.length)
 167                 head -= pipe->native.length;
 168
 169         return head;
 170 }
 171
 172 static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
 173                                 const void *hdr, size_t hlen,
 174                                 const void *data, size_t dlen)
 175 {
 176         struct glink_smem_pipe *pipe = to_smem_pipe(glink_pipe);
 177         unsigned int head;
 178
 179         head = le32_to_cpu(*pipe->head);
 180
 181         head = glink_smem_tx_write_one(pipe, head, hdr, hlen);
 182         head = glink_smem_tx_write_one(pipe, head, data, dlen);
 183
 184         /* Ensure head is always aligned to 8 bytes */
 185         head = ALIGN(head, 8);
 186         if (head >= pipe->native.length)
 187                 head -= pipe->native.length;
 188
 189         /* Ensure ordering of fifo and head update */
 190         wmb();
 191
 192         *pipe->head = cpu_to_le32(head);
 193 }
 194
 195 static void glink_smem_tx_kick(struct qcom_glink_pipe *glink_pipe)
 196 {
 197         struct glink_smem_pipe *pipe = to_smem_pipe(glink_pipe);
 198         struct qcom_glink_smem *smem = pipe->smem;
 199
 200         mbox_send_message(smem->mbox_chan, NULL);
 201         mbox_client_txdone(smem->mbox_chan, 0);
 202 }
 203
 204 static irqreturn_t qcom_glink_smem_intr(int irq, void *data)
 205 {
 206         struct qcom_glink_smem *smem = data;
 207
 208         qcom_glink_native_rx(smem->glink);
 209
 210         return IRQ_HANDLED;
 211 }
 212
 213 static void qcom_glink_smem_release(struct device *dev)
 214 {
 215         struct qcom_glink_smem *smem = container_of(dev, struct qcom_glink_smem, dev);
 216
 217         kfree(smem);
 218 }
 219
 220 struct qcom_glink_smem *qcom_glink_smem_register(struct device *parent,
 221                                                  struct device_node *node)
 222 {
 223         struct glink_smem_pipe *rx_pipe;
 224         struct glink_smem_pipe *tx_pipe;
 225         struct qcom_glink_smem *smem;
 226         struct qcom_glink *glink;
 227         struct device *dev;
 228         u32 remote_pid;
 229         __le32 *descs;
 230         size_t size;
 231         int ret;
 232
 233         smem = kzalloc(sizeof(*smem), GFP_KERNEL);
 234         if (!smem)
 235                 return ERR_PTR(-ENOMEM);
 236
 237         dev = &smem->dev;
 238
 239         dev->parent = parent;
 240         dev->of_node = node;
 241         dev->release = qcom_glink_smem_release;
 242         dev_set_name(dev, "%s:%pOFn", dev_name(parent->parent), node);
 243         ret = device_register(dev);
 244         if (ret) {
 245                 pr_err("failed to register glink edge\n");
 246                 put_device(dev);
 247                 return ERR_PTR(ret);
 248         }
 249
 250         ret = of_property_read_u32(dev->of_node, "qcom,remote-pid",
 251                                    &remote_pid);
 252         if (ret) {
 253                 dev_err(dev, "failed to parse qcom,remote-pid\n");
 254                 goto err_put_dev;
 255         }
 256
 257         smem->remote_pid = remote_pid;
 258
 259         rx_pipe = devm_kzalloc(dev, sizeof(*rx_pipe), GFP_KERNEL);
 260         tx_pipe = devm_kzalloc(dev, sizeof(*tx_pipe), GFP_KERNEL);
 261         if (!rx_pipe || !tx_pipe) {
 262                 ret = -ENOMEM;
 263                 goto err_put_dev;
 264         }
 265
 266         ret = qcom_smem_alloc(remote_pid,
 267                               SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, 32);
 268         if (ret && ret != -EEXIST) {
 269                 dev_err(dev, "failed to allocate glink descriptors\n");
 270                 goto err_put_dev;
 271         }
 272
 273         descs = qcom_smem_get(remote_pid,
 274                               SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, &size);
 275         if (IS_ERR(descs)) {
 276                 dev_err(dev, "failed to acquire xprt descriptor\n");
 277                 ret = PTR_ERR(descs);
 278                 goto err_put_dev;
 279         }
 280
 281         if (size != 32) {
 282                 dev_err(dev, "glink descriptor of invalid size\n");
 283                 ret = -EINVAL;
 284                 goto err_put_dev;
 285         }
 286
 287         tx_pipe->tail = &descs[0];
 288         tx_pipe->head = &descs[1];
 289         rx_pipe->tail = &descs[2];
 290         rx_pipe->head = &descs[3];
 291
 292         ret = qcom_smem_alloc(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
 293                               SZ_16K);
 294         if (ret && ret != -EEXIST) {
 295                 dev_err(dev, "failed to allocate TX fifo\n");
 296                 goto err_put_dev;
 297         }
 298
 299         tx_pipe->fifo = qcom_smem_get(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
 300                                       &tx_pipe->native.length);
 301         if (IS_ERR(tx_pipe->fifo)) {
 302                 dev_err(dev, "failed to acquire TX fifo\n");
 303                 ret = PTR_ERR(tx_pipe->fifo);
 304                 goto err_put_dev;
 305         }
 306
 307         smem->irq = of_irq_get(smem->dev.of_node, 0);
 308         ret = devm_request_irq(&smem->dev, smem->irq, qcom_glink_smem_intr,
 309                                IRQF_NO_SUSPEND | IRQF_NO_AUTOEN,
 310                                "glink-smem", smem);
 311         if (ret) {
 312                 dev_err(&smem->dev, "failed to request IRQ\n");
 313                 goto err_put_dev;
 314         }
 315
 316         smem->mbox_client.dev = &smem->dev;
 317         smem->mbox_client.knows_txdone = true;
 318         smem->mbox_chan = mbox_request_channel(&smem->mbox_client, 0);
 319         if (IS_ERR(smem->mbox_chan)) {
 320                 ret = dev_err_probe(&smem->dev, PTR_ERR(smem->mbox_chan),
 321                                     "failed to acquire IPC channel\n");
 322                 goto err_put_dev;
 323         }
 324
 325         rx_pipe->smem = smem;
 326         rx_pipe->native.avail = glink_smem_rx_avail;
 327         rx_pipe->native.peek = glink_smem_rx_peek;
 328         rx_pipe->native.advance = glink_smem_rx_advance;
 329
 330         tx_pipe->smem = smem;
 331         tx_pipe->native.avail = glink_smem_tx_avail;
 332         tx_pipe->native.write = glink_smem_tx_write;
 333         tx_pipe->native.kick = glink_smem_tx_kick;
 334
 335         *rx_pipe->tail = 0;
 336         *tx_pipe->head = 0;
 337
 338         glink = qcom_glink_native_probe(dev,
 339                                         GLINK_FEATURE_INTENT_REUSE,
 340                                         &rx_pipe->native, &tx_pipe->native,
 341                                         false);
 342         if (IS_ERR(glink)) {
 343                 ret = PTR_ERR(glink);
 344                 goto err_free_mbox;
 345         }
 346
 347         smem->glink = glink;
 348
 349         enable_irq(smem->irq);
 350
 351         return smem;
 352
 353 err_free_mbox:
 354         mbox_free_channel(smem->mbox_chan);
 355
 356 err_put_dev:
 357         device_unregister(dev);
 358
 359         return ERR_PTR(ret);
 360 }
 361 EXPORT_SYMBOL_GPL(qcom_glink_smem_register);
 362
 363 void qcom_glink_smem_unregister(struct qcom_glink_smem *smem)
 364 {
 365         struct qcom_glink *glink = smem->glink;
 366
 367         disable_irq(smem->irq);
 368
 369         qcom_glink_native_remove(glink);
 370
 371         mbox_free_channel(smem->mbox_chan);
 372         device_unregister(&smem->dev);
 373 }
 374 EXPORT_SYMBOL_GPL(qcom_glink_smem_unregister);
 375
 376 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@linaro.org>");
 377 MODULE_DESCRIPTION("Qualcomm GLINK SMEM driver");
 378 MODULE_LICENSE("GPL v2");