linux/drivers/crypto/caam/jr.c
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   1/*
   2 * CAAM/SEC 4.x transport/backend driver
   3 * JobR backend functionality
   4 *
   5 * Copyright 2008-2012 Freescale Semiconductor, Inc.
   6 */
   7
   8#include <linux/of_irq.h>
   9#include <linux/of_address.h>
  10
  11#include "compat.h"
  12#include "regs.h"
  13#include "jr.h"
  14#include "desc.h"
  15#include "intern.h"
  16
  17struct jr_driver_data {
  18        /* List of Physical JobR's with the Driver */
  19        struct list_head        jr_list;
  20        spinlock_t              jr_alloc_lock;  /* jr_list lock */
  21} ____cacheline_aligned;
  22
  23static struct jr_driver_data driver_data;
  24
  25static int caam_reset_hw_jr(struct device *dev)
  26{
  27        struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
  28        unsigned int timeout = 100000;
  29
  30        /*
  31         * mask interrupts since we are going to poll
  32         * for reset completion status
  33         */
  34        setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
  35
  36        /* initiate flush (required prior to reset) */
  37        wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
  38        while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
  39                JRINT_ERR_HALT_INPROGRESS) && --timeout)
  40                cpu_relax();
  41
  42        if ((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) !=
  43            JRINT_ERR_HALT_COMPLETE || timeout == 0) {
  44                dev_err(dev, "failed to flush job ring %d\n", jrp->ridx);
  45                return -EIO;
  46        }
  47
  48        /* initiate reset */
  49        timeout = 100000;
  50        wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
  51        while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
  52                cpu_relax();
  53
  54        if (timeout == 0) {
  55                dev_err(dev, "failed to reset job ring %d\n", jrp->ridx);
  56                return -EIO;
  57        }
  58
  59        /* unmask interrupts */
  60        clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
  61
  62        return 0;
  63}
  64
  65/*
  66 * Shutdown JobR independent of platform property code
  67 */
  68static int caam_jr_shutdown(struct device *dev)
  69{
  70        struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
  71        dma_addr_t inpbusaddr, outbusaddr;
  72        int ret;
  73
  74        ret = caam_reset_hw_jr(dev);
  75
  76        tasklet_kill(&jrp->irqtask);
  77
  78        /* Release interrupt */
  79        free_irq(jrp->irq, dev);
  80
  81        /* Free rings */
  82        inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
  83        outbusaddr = rd_reg64(&jrp->rregs->outring_base);
  84        dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
  85                          jrp->inpring, inpbusaddr);
  86        dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
  87                          jrp->outring, outbusaddr);
  88        kfree(jrp->entinfo);
  89
  90        return ret;
  91}
  92
  93static int caam_jr_remove(struct platform_device *pdev)
  94{
  95        int ret;
  96        struct device *jrdev;
  97        struct caam_drv_private_jr *jrpriv;
  98
  99        jrdev = &pdev->dev;
 100        jrpriv = dev_get_drvdata(jrdev);
 101
 102        /*
 103         * Return EBUSY if job ring already allocated.
 104         */
 105        if (atomic_read(&jrpriv->tfm_count)) {
 106                dev_err(jrdev, "Device is busy\n");
 107                return -EBUSY;
 108        }
 109
 110        /* Remove the node from Physical JobR list maintained by driver */
 111        spin_lock(&driver_data.jr_alloc_lock);
 112        list_del(&jrpriv->list_node);
 113        spin_unlock(&driver_data.jr_alloc_lock);
 114
 115        /* Release ring */
 116        ret = caam_jr_shutdown(jrdev);
 117        if (ret)
 118                dev_err(jrdev, "Failed to shut down job ring\n");
 119        irq_dispose_mapping(jrpriv->irq);
 120
 121        return ret;
 122}
 123
 124/* Main per-ring interrupt handler */
 125static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
 126{
 127        struct device *dev = st_dev;
 128        struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
 129        u32 irqstate;
 130
 131        /*
 132         * Check the output ring for ready responses, kick
 133         * tasklet if jobs done.
 134         */
 135        irqstate = rd_reg32(&jrp->rregs->jrintstatus);
 136        if (!irqstate)
 137                return IRQ_NONE;
 138
 139        /*
 140         * If JobR error, we got more development work to do
 141         * Flag a bug now, but we really need to shut down and
 142         * restart the queue (and fix code).
 143         */
 144        if (irqstate & JRINT_JR_ERROR) {
 145                dev_err(dev, "job ring error: irqstate: %08x\n", irqstate);
 146                BUG();
 147        }
 148
 149        /* mask valid interrupts */
 150        setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
 151
 152        /* Have valid interrupt at this point, just ACK and trigger */
 153        wr_reg32(&jrp->rregs->jrintstatus, irqstate);
 154
 155        preempt_disable();
 156        tasklet_schedule(&jrp->irqtask);
 157        preempt_enable();
 158
 159        return IRQ_HANDLED;
 160}
 161
 162/* Deferred service handler, run as interrupt-fired tasklet */
 163static void caam_jr_dequeue(unsigned long devarg)
 164{
 165        int hw_idx, sw_idx, i, head, tail;
 166        struct device *dev = (struct device *)devarg;
 167        struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
 168        void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
 169        u32 *userdesc, userstatus;
 170        void *userarg;
 171
 172        while (rd_reg32(&jrp->rregs->outring_used)) {
 173
 174                head = ACCESS_ONCE(jrp->head);
 175
 176                spin_lock(&jrp->outlock);
 177
 178                sw_idx = tail = jrp->tail;
 179                hw_idx = jrp->out_ring_read_index;
 180
 181                for (i = 0; CIRC_CNT(head, tail + i, JOBR_DEPTH) >= 1; i++) {
 182                        sw_idx = (tail + i) & (JOBR_DEPTH - 1);
 183
 184                        if (jrp->outring[hw_idx].desc ==
 185                            jrp->entinfo[sw_idx].desc_addr_dma)
 186                                break; /* found */
 187                }
 188                /* we should never fail to find a matching descriptor */
 189                BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);
 190
 191                /* Unmap just-run descriptor so we can post-process */
 192                dma_unmap_single(dev, jrp->outring[hw_idx].desc,
 193                                 jrp->entinfo[sw_idx].desc_size,
 194                                 DMA_TO_DEVICE);
 195
 196                /* mark completed, avoid matching on a recycled desc addr */
 197                jrp->entinfo[sw_idx].desc_addr_dma = 0;
 198
 199                /* Stash callback params for use outside of lock */
 200                usercall = jrp->entinfo[sw_idx].callbk;
 201                userarg = jrp->entinfo[sw_idx].cbkarg;
 202                userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
 203                userstatus = jrp->outring[hw_idx].jrstatus;
 204
 205                /*
 206                 * Make sure all information from the job has been obtained
 207                 * before telling CAAM that the job has been removed from the
 208                 * output ring.
 209                 */
 210                mb();
 211
 212                /* set done */
 213                wr_reg32(&jrp->rregs->outring_rmvd, 1);
 214
 215                jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
 216                                           (JOBR_DEPTH - 1);
 217
 218                /*
 219                 * if this job completed out-of-order, do not increment
 220                 * the tail.  Otherwise, increment tail by 1 plus the
 221                 * number of subsequent jobs already completed out-of-order
 222                 */
 223                if (sw_idx == tail) {
 224                        do {
 225                                tail = (tail + 1) & (JOBR_DEPTH - 1);
 226                        } while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
 227                                 jrp->entinfo[tail].desc_addr_dma == 0);
 228
 229                        jrp->tail = tail;
 230                }
 231
 232                spin_unlock(&jrp->outlock);
 233
 234                /* Finally, execute user's callback */
 235                usercall(dev, userdesc, userstatus, userarg);
 236        }
 237
 238        /* reenable / unmask IRQs */
 239        clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
 240}
 241
 242/**
 243 * caam_jr_alloc() - Alloc a job ring for someone to use as needed.
 244 *
 245 * returns :  pointer to the newly allocated physical
 246 *            JobR dev can be written to if successful.
 247 **/
 248struct device *caam_jr_alloc(void)
 249{
 250        struct caam_drv_private_jr *jrpriv, *min_jrpriv = NULL;
 251        struct device *dev = ERR_PTR(-ENODEV);
 252        int min_tfm_cnt = INT_MAX;
 253        int tfm_cnt;
 254
 255        spin_lock(&driver_data.jr_alloc_lock);
 256
 257        if (list_empty(&driver_data.jr_list)) {
 258                spin_unlock(&driver_data.jr_alloc_lock);
 259                return ERR_PTR(-ENODEV);
 260        }
 261
 262        list_for_each_entry(jrpriv, &driver_data.jr_list, list_node) {
 263                tfm_cnt = atomic_read(&jrpriv->tfm_count);
 264                if (tfm_cnt < min_tfm_cnt) {
 265                        min_tfm_cnt = tfm_cnt;
 266                        min_jrpriv = jrpriv;
 267                }
 268                if (!min_tfm_cnt)
 269                        break;
 270        }
 271
 272        if (min_jrpriv) {
 273                atomic_inc(&min_jrpriv->tfm_count);
 274                dev = min_jrpriv->dev;
 275        }
 276        spin_unlock(&driver_data.jr_alloc_lock);
 277
 278        return dev;
 279}
 280EXPORT_SYMBOL(caam_jr_alloc);
 281
 282/**
 283 * caam_jr_free() - Free the Job Ring
 284 * @rdev     - points to the dev that identifies the Job ring to
 285 *             be released.
 286 **/
 287void caam_jr_free(struct device *rdev)
 288{
 289        struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
 290
 291        atomic_dec(&jrpriv->tfm_count);
 292}
 293EXPORT_SYMBOL(caam_jr_free);
 294
 295/**
 296 * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
 297 * -EBUSY if the queue is full, -EIO if it cannot map the caller's
 298 * descriptor.
 299 * @dev:  device of the job ring to be used. This device should have
 300 *        been assigned prior by caam_jr_register().
 301 * @desc: points to a job descriptor that execute our request. All
 302 *        descriptors (and all referenced data) must be in a DMAable
 303 *        region, and all data references must be physical addresses
 304 *        accessible to CAAM (i.e. within a PAMU window granted
 305 *        to it).
 306 * @cbk:  pointer to a callback function to be invoked upon completion
 307 *        of this request. This has the form:
 308 *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
 309 *        where:
 310 *        @dev:    contains the job ring device that processed this
 311 *                 response.
 312 *        @desc:   descriptor that initiated the request, same as
 313 *                 "desc" being argued to caam_jr_enqueue().
 314 *        @status: untranslated status received from CAAM. See the
 315 *                 reference manual for a detailed description of
 316 *                 error meaning, or see the JRSTA definitions in the
 317 *                 register header file
 318 *        @areq:   optional pointer to an argument passed with the
 319 *                 original request
 320 * @areq: optional pointer to a user argument for use at callback
 321 *        time.
 322 **/
 323int caam_jr_enqueue(struct device *dev, u32 *desc,
 324                    void (*cbk)(struct device *dev, u32 *desc,
 325                                u32 status, void *areq),
 326                    void *areq)
 327{
 328        struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
 329        struct caam_jrentry_info *head_entry;
 330        int head, tail, desc_size;
 331        dma_addr_t desc_dma;
 332
 333        desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32);
 334        desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
 335        if (dma_mapping_error(dev, desc_dma)) {
 336                dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
 337                return -EIO;
 338        }
 339
 340        spin_lock_bh(&jrp->inplock);
 341
 342        head = jrp->head;
 343        tail = ACCESS_ONCE(jrp->tail);
 344
 345        if (!rd_reg32(&jrp->rregs->inpring_avail) ||
 346            CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
 347                spin_unlock_bh(&jrp->inplock);
 348                dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
 349                return -EBUSY;
 350        }
 351
 352        head_entry = &jrp->entinfo[head];
 353        head_entry->desc_addr_virt = desc;
 354        head_entry->desc_size = desc_size;
 355        head_entry->callbk = (void *)cbk;
 356        head_entry->cbkarg = areq;
 357        head_entry->desc_addr_dma = desc_dma;
 358
 359        jrp->inpring[jrp->inp_ring_write_index] = desc_dma;
 360
 361        /*
 362         * Guarantee that the descriptor's DMA address has been written to
 363         * the next slot in the ring before the write index is updated, since
 364         * other cores may update this index independently.
 365         */
 366        smp_wmb();
 367
 368        jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
 369                                    (JOBR_DEPTH - 1);
 370        jrp->head = (head + 1) & (JOBR_DEPTH - 1);
 371
 372        /*
 373         * Ensure that all job information has been written before
 374         * notifying CAAM that a new job was added to the input ring.
 375         */
 376        wmb();
 377
 378        wr_reg32(&jrp->rregs->inpring_jobadd, 1);
 379
 380        spin_unlock_bh(&jrp->inplock);
 381
 382        return 0;
 383}
 384EXPORT_SYMBOL(caam_jr_enqueue);
 385
 386/*
 387 * Init JobR independent of platform property detection
 388 */
 389static int caam_jr_init(struct device *dev)
 390{
 391        struct caam_drv_private_jr *jrp;
 392        dma_addr_t inpbusaddr, outbusaddr;
 393        int i, error;
 394
 395        jrp = dev_get_drvdata(dev);
 396
 397        tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);
 398
 399        /* Connect job ring interrupt handler. */
 400        error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
 401                            dev_name(dev), dev);
 402        if (error) {
 403                dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
 404                        jrp->ridx, jrp->irq);
 405                goto out_kill_deq;
 406        }
 407
 408        error = caam_reset_hw_jr(dev);
 409        if (error)
 410                goto out_free_irq;
 411
 412        error = -ENOMEM;
 413        jrp->inpring = dma_alloc_coherent(dev, sizeof(*jrp->inpring) *
 414                                          JOBR_DEPTH, &inpbusaddr, GFP_KERNEL);
 415        if (!jrp->inpring)
 416                goto out_free_irq;
 417
 418        jrp->outring = dma_alloc_coherent(dev, sizeof(*jrp->outring) *
 419                                          JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
 420        if (!jrp->outring)
 421                goto out_free_inpring;
 422
 423        jrp->entinfo = kcalloc(JOBR_DEPTH, sizeof(*jrp->entinfo), GFP_KERNEL);
 424        if (!jrp->entinfo)
 425                goto out_free_outring;
 426
 427        for (i = 0; i < JOBR_DEPTH; i++)
 428                jrp->entinfo[i].desc_addr_dma = !0;
 429
 430        /* Setup rings */
 431        jrp->inp_ring_write_index = 0;
 432        jrp->out_ring_read_index = 0;
 433        jrp->head = 0;
 434        jrp->tail = 0;
 435
 436        wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
 437        wr_reg64(&jrp->rregs->outring_base, outbusaddr);
 438        wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
 439        wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);
 440
 441        jrp->ringsize = JOBR_DEPTH;
 442
 443        spin_lock_init(&jrp->inplock);
 444        spin_lock_init(&jrp->outlock);
 445
 446        /* Select interrupt coalescing parameters */
 447        setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
 448                  (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
 449                  (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));
 450
 451        return 0;
 452
 453out_free_outring:
 454        dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
 455                          jrp->outring, outbusaddr);
 456out_free_inpring:
 457        dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
 458                          jrp->inpring, inpbusaddr);
 459        dev_err(dev, "can't allocate job rings for %d\n", jrp->ridx);
 460out_free_irq:
 461        free_irq(jrp->irq, dev);
 462out_kill_deq:
 463        tasklet_kill(&jrp->irqtask);
 464        return error;
 465}
 466
 467
 468/*
 469 * Probe routine for each detected JobR subsystem.
 470 */
 471static int caam_jr_probe(struct platform_device *pdev)
 472{
 473        struct device *jrdev;
 474        struct device_node *nprop;
 475        struct caam_job_ring __iomem *ctrl;
 476        struct caam_drv_private_jr *jrpriv;
 477        static int total_jobrs;
 478        int error;
 479
 480        jrdev = &pdev->dev;
 481        jrpriv = devm_kmalloc(jrdev, sizeof(*jrpriv), GFP_KERNEL);
 482        if (!jrpriv)
 483                return -ENOMEM;
 484
 485        dev_set_drvdata(jrdev, jrpriv);
 486
 487        /* save ring identity relative to detection */
 488        jrpriv->ridx = total_jobrs++;
 489
 490        nprop = pdev->dev.of_node;
 491        /* Get configuration properties from device tree */
 492        /* First, get register page */
 493        ctrl = of_iomap(nprop, 0);
 494        if (!ctrl) {
 495                dev_err(jrdev, "of_iomap() failed\n");
 496                return -ENOMEM;
 497        }
 498
 499        jrpriv->rregs = (struct caam_job_ring __force *)ctrl;
 500
 501        if (sizeof(dma_addr_t) == sizeof(u64))
 502                if (of_device_is_compatible(nprop, "fsl,sec-v5.0-job-ring"))
 503                        dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(40));
 504                else
 505                        dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(36));
 506        else
 507                dma_set_mask_and_coherent(jrdev, DMA_BIT_MASK(32));
 508
 509        /* Identify the interrupt */
 510        jrpriv->irq = irq_of_parse_and_map(nprop, 0);
 511
 512        /* Now do the platform independent part */
 513        error = caam_jr_init(jrdev); /* now turn on hardware */
 514        if (error) {
 515                irq_dispose_mapping(jrpriv->irq);
 516                return error;
 517        }
 518
 519        jrpriv->dev = jrdev;
 520        spin_lock(&driver_data.jr_alloc_lock);
 521        list_add_tail(&jrpriv->list_node, &driver_data.jr_list);
 522        spin_unlock(&driver_data.jr_alloc_lock);
 523
 524        atomic_set(&jrpriv->tfm_count, 0);
 525
 526        return 0;
 527}
 528
 529static struct of_device_id caam_jr_match[] = {
 530        {
 531                .compatible = "fsl,sec-v4.0-job-ring",
 532        },
 533        {
 534                .compatible = "fsl,sec4.0-job-ring",
 535        },
 536        {},
 537};
 538MODULE_DEVICE_TABLE(of, caam_jr_match);
 539
 540static struct platform_driver caam_jr_driver = {
 541        .driver = {
 542                .name = "caam_jr",
 543                .of_match_table = caam_jr_match,
 544        },
 545        .probe       = caam_jr_probe,
 546        .remove      = caam_jr_remove,
 547};
 548
 549static int __init jr_driver_init(void)
 550{
 551        spin_lock_init(&driver_data.jr_alloc_lock);
 552        INIT_LIST_HEAD(&driver_data.jr_list);
 553        return platform_driver_register(&caam_jr_driver);
 554}
 555
 556static void __exit jr_driver_exit(void)
 557{
 558        platform_driver_unregister(&caam_jr_driver);
 559}
 560
 561module_init(jr_driver_init);
 562module_exit(jr_driver_exit);
 563
 564MODULE_LICENSE("GPL");
 565MODULE_DESCRIPTION("FSL CAAM JR request backend");
 566MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");
 567
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