uboot/drivers/virtio/virtio_mmio.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2018, Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
   4 * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
   5 *
   6 * VirtIO memory-maped I/O transport driver
   7 * Ported from Linux drivers/virtio/virtio_mmio.c
   8 */
   9
  10#include <common.h>
  11#include <dm.h>
  12#include <virtio_types.h>
  13#include <virtio.h>
  14#include <virtio_ring.h>
  15#include <linux/compat.h>
  16#include <linux/err.h>
  17#include <linux/io.h>
  18#include "virtio_mmio.h"
  19
  20static int virtio_mmio_get_config(struct udevice *udev, unsigned int offset,
  21                                  void *buf, unsigned int len)
  22{
  23        struct virtio_mmio_priv *priv = dev_get_priv(udev);
  24        void __iomem *base = priv->base + VIRTIO_MMIO_CONFIG;
  25        u8 b;
  26        __le16 w;
  27        __le32 l;
  28
  29        if (priv->version == 1) {
  30                u8 *ptr = buf;
  31                int i;
  32
  33                for (i = 0; i < len; i++)
  34                        ptr[i] = readb(base + offset + i);
  35
  36                return 0;
  37        }
  38
  39        switch (len) {
  40        case 1:
  41                b = readb(base + offset);
  42                memcpy(buf, &b, sizeof(b));
  43                break;
  44        case 2:
  45                w = cpu_to_le16(readw(base + offset));
  46                memcpy(buf, &w, sizeof(w));
  47                break;
  48        case 4:
  49                l = cpu_to_le32(readl(base + offset));
  50                memcpy(buf, &l, sizeof(l));
  51                break;
  52        case 8:
  53                l = cpu_to_le32(readl(base + offset));
  54                memcpy(buf, &l, sizeof(l));
  55                l = cpu_to_le32(readl(base + offset + sizeof(l)));
  56                memcpy(buf + sizeof(l), &l, sizeof(l));
  57                break;
  58        default:
  59                WARN_ON(true);
  60        }
  61
  62        return 0;
  63}
  64
  65static int virtio_mmio_set_config(struct udevice *udev, unsigned int offset,
  66                                  const void *buf, unsigned int len)
  67{
  68        struct virtio_mmio_priv *priv = dev_get_priv(udev);
  69        void __iomem *base = priv->base + VIRTIO_MMIO_CONFIG;
  70        u8 b;
  71        __le16 w;
  72        __le32 l;
  73
  74        if (priv->version == 1) {
  75                const u8 *ptr = buf;
  76                int i;
  77
  78                for (i = 0; i < len; i++)
  79                        writeb(ptr[i], base + offset + i);
  80
  81                return 0;
  82        }
  83
  84        switch (len) {
  85        case 1:
  86                memcpy(&b, buf, sizeof(b));
  87                writeb(b, base + offset);
  88                break;
  89        case 2:
  90                memcpy(&w, buf, sizeof(w));
  91                writew(le16_to_cpu(w), base + offset);
  92                break;
  93        case 4:
  94                memcpy(&l, buf, sizeof(l));
  95                writel(le32_to_cpu(l), base + offset);
  96                break;
  97        case 8:
  98                memcpy(&l, buf, sizeof(l));
  99                writel(le32_to_cpu(l), base + offset);
 100                memcpy(&l, buf + sizeof(l), sizeof(l));
 101                writel(le32_to_cpu(l), base + offset + sizeof(l));
 102                break;
 103        default:
 104                WARN_ON(true);
 105        }
 106
 107        return 0;
 108}
 109
 110static int virtio_mmio_generation(struct udevice *udev, u32 *counter)
 111{
 112        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 113
 114        if (priv->version == 1)
 115                *counter = 0;
 116        else
 117                *counter = readl(priv->base + VIRTIO_MMIO_CONFIG_GENERATION);
 118
 119        return 0;
 120}
 121
 122static int virtio_mmio_get_status(struct udevice *udev, u8 *status)
 123{
 124        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 125
 126        *status = readl(priv->base + VIRTIO_MMIO_STATUS) & 0xff;
 127
 128        return 0;
 129}
 130
 131static int virtio_mmio_set_status(struct udevice *udev, u8 status)
 132{
 133        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 134
 135        /* We should never be setting status to 0 */
 136        WARN_ON(status == 0);
 137
 138        writel(status, priv->base + VIRTIO_MMIO_STATUS);
 139
 140        return 0;
 141}
 142
 143static int virtio_mmio_reset(struct udevice *udev)
 144{
 145        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 146
 147        /* 0 status means a reset */
 148        writel(0, priv->base + VIRTIO_MMIO_STATUS);
 149
 150        return 0;
 151}
 152
 153static int virtio_mmio_get_features(struct udevice *udev, u64 *features)
 154{
 155        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 156
 157        writel(1, priv->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
 158        *features = readl(priv->base + VIRTIO_MMIO_DEVICE_FEATURES);
 159        *features <<= 32;
 160
 161        writel(0, priv->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
 162        *features |= readl(priv->base + VIRTIO_MMIO_DEVICE_FEATURES);
 163
 164        return 0;
 165}
 166
 167static int virtio_mmio_set_features(struct udevice *udev)
 168{
 169        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 170        struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
 171
 172        /* Make sure there is are no mixed devices */
 173        if (priv->version == 2 && uc_priv->legacy) {
 174                debug("New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
 175                return -EINVAL;
 176        }
 177
 178        writel(1, priv->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
 179        writel((u32)(uc_priv->features >> 32),
 180               priv->base + VIRTIO_MMIO_DRIVER_FEATURES);
 181
 182        writel(0, priv->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
 183        writel((u32)uc_priv->features,
 184               priv->base + VIRTIO_MMIO_DRIVER_FEATURES);
 185
 186        return 0;
 187}
 188
 189static struct virtqueue *virtio_mmio_setup_vq(struct udevice *udev,
 190                                              unsigned int index)
 191{
 192        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 193        struct virtqueue *vq;
 194        unsigned int num;
 195        int err;
 196
 197        /* Select the queue we're interested in */
 198        writel(index, priv->base + VIRTIO_MMIO_QUEUE_SEL);
 199
 200        /* Queue shouldn't already be set up */
 201        if (readl(priv->base + (priv->version == 1 ?
 202            VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
 203                err = -ENOENT;
 204                goto error_available;
 205        }
 206
 207        num = readl(priv->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
 208        if (num == 0) {
 209                err = -ENOENT;
 210                goto error_new_virtqueue;
 211        }
 212
 213        /* Create the vring */
 214        vq = vring_create_virtqueue(index, num, VIRTIO_MMIO_VRING_ALIGN, udev);
 215        if (!vq) {
 216                err = -ENOMEM;
 217                goto error_new_virtqueue;
 218        }
 219
 220        /* Activate the queue */
 221        writel(virtqueue_get_vring_size(vq),
 222               priv->base + VIRTIO_MMIO_QUEUE_NUM);
 223        if (priv->version == 1) {
 224                u64 q_pfn = virtqueue_get_desc_addr(vq) >> PAGE_SHIFT;
 225
 226                /*
 227                 * virtio-mmio v1 uses a 32bit QUEUE PFN. If we have something
 228                 * that doesn't fit in 32bit, fail the setup rather than
 229                 * pretending to be successful.
 230                 */
 231                if (q_pfn >> 32) {
 232                        debug("platform bug: legacy virtio-mmio must not be used with RAM above 0x%llxGB\n",
 233                              0x1ULL << (32 + PAGE_SHIFT - 30));
 234                        err = -E2BIG;
 235                        goto error_bad_pfn;
 236                }
 237
 238                writel(PAGE_SIZE, priv->base + VIRTIO_MMIO_QUEUE_ALIGN);
 239                writel(q_pfn, priv->base + VIRTIO_MMIO_QUEUE_PFN);
 240        } else {
 241                u64 addr;
 242
 243                addr = virtqueue_get_desc_addr(vq);
 244                writel((u32)addr, priv->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
 245                writel((u32)(addr >> 32),
 246                       priv->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
 247
 248                addr = virtqueue_get_avail_addr(vq);
 249                writel((u32)addr, priv->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
 250                writel((u32)(addr >> 32),
 251                       priv->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
 252
 253                addr = virtqueue_get_used_addr(vq);
 254                writel((u32)addr, priv->base + VIRTIO_MMIO_QUEUE_USED_LOW);
 255                writel((u32)(addr >> 32),
 256                       priv->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
 257
 258                writel(1, priv->base + VIRTIO_MMIO_QUEUE_READY);
 259        }
 260
 261        return vq;
 262
 263error_bad_pfn:
 264        vring_del_virtqueue(vq);
 265
 266error_new_virtqueue:
 267        if (priv->version == 1) {
 268                writel(0, priv->base + VIRTIO_MMIO_QUEUE_PFN);
 269        } else {
 270                writel(0, priv->base + VIRTIO_MMIO_QUEUE_READY);
 271                WARN_ON(readl(priv->base + VIRTIO_MMIO_QUEUE_READY));
 272        }
 273
 274error_available:
 275        return ERR_PTR(err);
 276}
 277
 278static void virtio_mmio_del_vq(struct virtqueue *vq)
 279{
 280        struct virtio_mmio_priv *priv = dev_get_priv(vq->vdev);
 281        unsigned int index = vq->index;
 282
 283        /* Select and deactivate the queue */
 284        writel(index, priv->base + VIRTIO_MMIO_QUEUE_SEL);
 285        if (priv->version == 1) {
 286                writel(0, priv->base + VIRTIO_MMIO_QUEUE_PFN);
 287        } else {
 288                writel(0, priv->base + VIRTIO_MMIO_QUEUE_READY);
 289                WARN_ON(readl(priv->base + VIRTIO_MMIO_QUEUE_READY));
 290        }
 291
 292        vring_del_virtqueue(vq);
 293}
 294
 295static int virtio_mmio_del_vqs(struct udevice *udev)
 296{
 297        struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
 298        struct virtqueue *vq, *n;
 299
 300        list_for_each_entry_safe(vq, n, &uc_priv->vqs, list)
 301                virtio_mmio_del_vq(vq);
 302
 303        return 0;
 304}
 305
 306static int virtio_mmio_find_vqs(struct udevice *udev, unsigned int nvqs,
 307                                struct virtqueue *vqs[])
 308{
 309        int i;
 310
 311        for (i = 0; i < nvqs; ++i) {
 312                vqs[i] = virtio_mmio_setup_vq(udev, i);
 313                if (IS_ERR(vqs[i])) {
 314                        virtio_mmio_del_vqs(udev);
 315                        return PTR_ERR(vqs[i]);
 316                }
 317        }
 318
 319        return 0;
 320}
 321
 322static int virtio_mmio_notify(struct udevice *udev, struct virtqueue *vq)
 323{
 324        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 325
 326        /*
 327         * We write the queue's selector into the notification register
 328         * to signal the other end
 329         */
 330        writel(vq->index, priv->base + VIRTIO_MMIO_QUEUE_NOTIFY);
 331
 332        return 0;
 333}
 334
 335static int virtio_mmio_ofdata_to_platdata(struct udevice *udev)
 336{
 337        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 338
 339        priv->base = (void __iomem *)(ulong)dev_read_addr(udev);
 340        if (priv->base == (void __iomem *)FDT_ADDR_T_NONE)
 341                return -EINVAL;
 342
 343        return 0;
 344}
 345
 346static int virtio_mmio_probe(struct udevice *udev)
 347{
 348        struct virtio_mmio_priv *priv = dev_get_priv(udev);
 349        struct virtio_dev_priv *uc_priv = dev_get_uclass_priv(udev);
 350        u32 magic;
 351
 352        /* Check magic value */
 353        magic = readl(priv->base + VIRTIO_MMIO_MAGIC_VALUE);
 354        if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24)) {
 355                debug("(%s): wrong magic value 0x%08x!\n", udev->name, magic);
 356                return 0;
 357        }
 358
 359        /* Check device version */
 360        priv->version = readl(priv->base + VIRTIO_MMIO_VERSION);
 361        if (priv->version < 1 || priv->version > 2) {
 362                debug("(%s): version %d not supported!\n",
 363                      udev->name, priv->version);
 364                return 0;
 365        }
 366
 367        /* Check device ID */
 368        uc_priv->device = readl(priv->base + VIRTIO_MMIO_DEVICE_ID);
 369        if (uc_priv->device == 0) {
 370                /*
 371                 * virtio-mmio device with an ID 0 is a (dummy) placeholder
 372                 * with no function. End probing now with no error reported.
 373                 */
 374                return 0;
 375        }
 376        uc_priv->vendor = readl(priv->base + VIRTIO_MMIO_VENDOR_ID);
 377
 378        if (priv->version == 1)
 379                writel(PAGE_SIZE, priv->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
 380
 381        debug("(%s): device (%d) vendor (%08x) version (%d)\n", udev->name,
 382              uc_priv->device, uc_priv->vendor, priv->version);
 383
 384        return 0;
 385}
 386
 387static const struct dm_virtio_ops virtio_mmio_ops = {
 388        .get_config     = virtio_mmio_get_config,
 389        .set_config     = virtio_mmio_set_config,
 390        .generation     = virtio_mmio_generation,
 391        .get_status     = virtio_mmio_get_status,
 392        .set_status     = virtio_mmio_set_status,
 393        .reset          = virtio_mmio_reset,
 394        .get_features   = virtio_mmio_get_features,
 395        .set_features   = virtio_mmio_set_features,
 396        .find_vqs       = virtio_mmio_find_vqs,
 397        .del_vqs        = virtio_mmio_del_vqs,
 398        .notify         = virtio_mmio_notify,
 399};
 400
 401static const struct udevice_id virtio_mmio_ids[] = {
 402        { .compatible = "virtio,mmio" },
 403        { }
 404};
 405
 406U_BOOT_DRIVER(virtio_mmio) = {
 407        .name   = "virtio-mmio",
 408        .id     = UCLASS_VIRTIO,
 409        .of_match = virtio_mmio_ids,
 410        .ops    = &virtio_mmio_ops,
 411        .probe  = virtio_mmio_probe,
 412        .ofdata_to_platdata = virtio_mmio_ofdata_to_platdata,
 413        .priv_auto_alloc_size = sizeof(struct virtio_mmio_priv),
 414};
 415