jr.c

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/*
 * CAAM/SEC 4.x transport/backend driver
 * JobR backend functionality
 *
 * Copyright 2008-2012 Freescale Semiconductor, Inc.
 */

#include "compat.h"
#include "regs.h"
#include "jr.h"
#include "desc.h"
#include "intern.h"

/* Main per-ring interrupt handler */
static irqreturn_t caam_jr_interrupt(int irq, void *st_dev)
{
    struct device *dev = st_dev;
    struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
    u32 irqstate;

    /*
     * Check the output ring for ready responses, kick
     * tasklet if jobs done.
     */
    irqstate = rd_reg32(&jrp->rregs->jrintstatus);
    if (!irqstate)
        return IRQ_NONE;

    /*
     * If JobR error, we got more development work to do
     * Flag a bug now, but we really need to shut down and
     * restart the queue (and fix code).
     */
    if (irqstate & JRINT_JR_ERROR) {
        dev_err(dev, "job ring error: irqstate: %08x\n", irqstate);
        BUG();
    }

    /* mask valid interrupts */
    setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);

    /* Have valid interrupt at this point, just ACK and trigger */
    wr_reg32(&jrp->rregs->jrintstatus, irqstate);

    preempt_disable();
    tasklet_schedule(&jrp->irqtask);
    preempt_enable();

    return IRQ_HANDLED;
}

/* Deferred service handler, run as interrupt-fired tasklet */
static void caam_jr_dequeue(unsigned long devarg)
{
    int hw_idx, sw_idx, i, head, tail;
    struct device *dev = (struct device *)devarg;
    struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
    void (*usercall)(struct device *dev, u32 *desc, u32 status, void *arg);
    u32 *userdesc, userstatus;
    void *userarg;

    while (rd_reg32(&jrp->rregs->outring_used)) {

        head = ACCESS_ONCE(jrp->head);

        spin_lock(&jrp->outlock);

        sw_idx = tail = jrp->tail;
        hw_idx = jrp->out_ring_read_index;

        for (i = 0; CIRC_CNT(head, tail + i, JOBR_DEPTH) >= 1; i++) {
            sw_idx = (tail + i) & (JOBR_DEPTH - 1);

            smp_read_barrier_depends();

            if (jrp->outring[hw_idx].desc ==
                jrp->entinfo[sw_idx].desc_addr_dma)
                break; /* found */
        }
        /* we should never fail to find a matching descriptor */
        BUG_ON(CIRC_CNT(head, tail + i, JOBR_DEPTH) <= 0);

        /* Unmap just-run descriptor so we can post-process */
        dma_unmap_single(dev, jrp->outring[hw_idx].desc,
                 jrp->entinfo[sw_idx].desc_size,
                 DMA_TO_DEVICE);

        /* mark completed, avoid matching on a recycled desc addr */
        jrp->entinfo[sw_idx].desc_addr_dma = 0;

        /* Stash callback params for use outside of lock */
        usercall = jrp->entinfo[sw_idx].callbk;
        userarg = jrp->entinfo[sw_idx].cbkarg;
        userdesc = jrp->entinfo[sw_idx].desc_addr_virt;
        userstatus = jrp->outring[hw_idx].jrstatus;

        /* set done */
        wr_reg32(&jrp->rregs->outring_rmvd, 1);

        jrp->out_ring_read_index = (jrp->out_ring_read_index + 1) &
                       (JOBR_DEPTH - 1);

        /*
         * if this job completed out-of-order, do not increment
         * the tail.  Otherwise, increment tail by 1 plus the
         * number of subsequent jobs already completed out-of-order
         */
        if (sw_idx == tail) {
            do {
                tail = (tail + 1) & (JOBR_DEPTH - 1);
                smp_read_barrier_depends();
            } while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
                 jrp->entinfo[tail].desc_addr_dma == 0);

            jrp->tail = tail;
        }

        spin_unlock(&jrp->outlock);

        /* Finally, execute user's callback */
        usercall(dev, userdesc, userstatus, userarg);
    }

    /* reenable / unmask IRQs */
    clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);
}

int caam_jr_register(struct device *ctrldev, struct device **rdev)
{
    struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
    struct caam_drv_private_jr *jrpriv = NULL;
    int ring;

    /* Lock, if free ring - assign, unlock */
    spin_lock(&ctrlpriv->jr_alloc_lock);
    for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
        jrpriv = dev_get_drvdata(ctrlpriv->jrdev[ring]);
        if (jrpriv->assign == JOBR_UNASSIGNED) {
            jrpriv->assign = JOBR_ASSIGNED;
            *rdev = ctrlpriv->jrdev[ring];
            spin_unlock(&ctrlpriv->jr_alloc_lock);
            return ring;
        }
    }

    /* If assigned, write dev where caller needs it */
    spin_unlock(&ctrlpriv->jr_alloc_lock);
    *rdev = NULL;

    return -ENODEV;
}
EXPORT_SYMBOL(caam_jr_register);

int caam_jr_deregister(struct device *rdev)
{
    struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
    struct caam_drv_private *ctrlpriv;

    /* Get the owning controller's private space */
    ctrlpriv = dev_get_drvdata(jrpriv->parentdev);

    /*
     * Make sure ring empty before release
     */
    if (rd_reg32(&jrpriv->rregs->outring_used) ||
        (rd_reg32(&jrpriv->rregs->inpring_avail) != JOBR_DEPTH))
        return -EBUSY;

    /* Release ring */
    spin_lock(&ctrlpriv->jr_alloc_lock);
    jrpriv->assign = JOBR_UNASSIGNED;
    spin_unlock(&ctrlpriv->jr_alloc_lock);

    return 0;
}
EXPORT_SYMBOL(caam_jr_deregister);

int caam_jr_enqueue(struct device *dev, u32 *desc,
            void (*cbk)(struct device *dev, u32 *desc,
                u32 status, void *areq),
            void *areq)
{
    struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
    struct caam_jrentry_info *head_entry;
    int head, tail, desc_size;
    dma_addr_t desc_dma;

    desc_size = (*desc & HDR_JD_LENGTH_MASK) * sizeof(u32);
    desc_dma = dma_map_single(dev, desc, desc_size, DMA_TO_DEVICE);
    if (dma_mapping_error(dev, desc_dma)) {
        dev_err(dev, "caam_jr_enqueue(): can't map jobdesc\n");
        return -EIO;
    }

    spin_lock_bh(&jrp->inplock);

    head = jrp->head;
    tail = ACCESS_ONCE(jrp->tail);

    if (!rd_reg32(&jrp->rregs->inpring_avail) ||
        CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
        spin_unlock_bh(&jrp->inplock);
        dma_unmap_single(dev, desc_dma, desc_size, DMA_TO_DEVICE);
        return -EBUSY;
    }

    head_entry = &jrp->entinfo[head];
    head_entry->desc_addr_virt = desc;
    head_entry->desc_size = desc_size;
    head_entry->callbk = (void *)cbk;
    head_entry->cbkarg = areq;
    head_entry->desc_addr_dma = desc_dma;

    jrp->inpring[jrp->inp_ring_write_index] = desc_dma;

    smp_wmb();

    jrp->inp_ring_write_index = (jrp->inp_ring_write_index + 1) &
                    (JOBR_DEPTH - 1);
    jrp->head = (head + 1) & (JOBR_DEPTH - 1);

    wr_reg32(&jrp->rregs->inpring_jobadd, 1);

    spin_unlock_bh(&jrp->inplock);

    return 0;
}
EXPORT_SYMBOL(caam_jr_enqueue);

static int caam_reset_hw_jr(struct device *dev)
{
    struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
    unsigned int timeout = 100000;

    /*
     * mask interrupts since we are going to poll
     * for reset completion status
     */
    setbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);

    /* initiate flush (required prior to reset) */
    wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
    while (((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) ==
        JRINT_ERR_HALT_INPROGRESS) && --timeout)
        cpu_relax();

    if ((rd_reg32(&jrp->rregs->jrintstatus) & JRINT_ERR_HALT_MASK) !=
        JRINT_ERR_HALT_COMPLETE || timeout == 0) {
        dev_err(dev, "failed to flush job ring %d\n", jrp->ridx);
        return -EIO;
    }

    /* initiate reset */
    timeout = 100000;
    wr_reg32(&jrp->rregs->jrcommand, JRCR_RESET);
    while ((rd_reg32(&jrp->rregs->jrcommand) & JRCR_RESET) && --timeout)
        cpu_relax();

    if (timeout == 0) {
        dev_err(dev, "failed to reset job ring %d\n", jrp->ridx);
        return -EIO;
    }

    /* unmask interrupts */
    clrbits32(&jrp->rregs->rconfig_lo, JRCFG_IMSK);

    return 0;
}

/*
 * Init JobR independent of platform property detection
 */
static int caam_jr_init(struct device *dev)
{
    struct caam_drv_private_jr *jrp;
    dma_addr_t inpbusaddr, outbusaddr;
    int i, error;

    jrp = dev_get_drvdata(dev);

    tasklet_init(&jrp->irqtask, caam_jr_dequeue, (unsigned long)dev);

    /* Connect job ring interrupt handler. */
    error = request_irq(jrp->irq, caam_jr_interrupt, IRQF_SHARED,
                "caam-jobr", dev);
    if (error) {
        dev_err(dev, "can't connect JobR %d interrupt (%d)\n",
            jrp->ridx, jrp->irq);
        irq_dispose_mapping(jrp->irq);
        jrp->irq = 0;
        return -EINVAL;
    }

    error = caam_reset_hw_jr(dev);
    if (error)
        return error;

    jrp->inpring = dma_alloc_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
                      &inpbusaddr, GFP_KERNEL);

    jrp->outring = dma_alloc_coherent(dev, sizeof(struct jr_outentry) *
                      JOBR_DEPTH, &outbusaddr, GFP_KERNEL);

    jrp->entinfo = kzalloc(sizeof(struct caam_jrentry_info) * JOBR_DEPTH,
                   GFP_KERNEL);

    if ((jrp->inpring == NULL) || (jrp->outring == NULL) ||
        (jrp->entinfo == NULL)) {
        dev_err(dev, "can't allocate job rings for %d\n",
            jrp->ridx);
        return -ENOMEM;
    }

    for (i = 0; i < JOBR_DEPTH; i++)
        jrp->entinfo[i].desc_addr_dma = !0;

    /* Setup rings */
    jrp->inp_ring_write_index = 0;
    jrp->out_ring_read_index = 0;
    jrp->head = 0;
    jrp->tail = 0;

    wr_reg64(&jrp->rregs->inpring_base, inpbusaddr);
    wr_reg64(&jrp->rregs->outring_base, outbusaddr);
    wr_reg32(&jrp->rregs->inpring_size, JOBR_DEPTH);
    wr_reg32(&jrp->rregs->outring_size, JOBR_DEPTH);

    jrp->ringsize = JOBR_DEPTH;

    spin_lock_init(&jrp->inplock);
    spin_lock_init(&jrp->outlock);

    /* Select interrupt coalescing parameters */
    setbits32(&jrp->rregs->rconfig_lo, JOBR_INTC |
          (JOBR_INTC_COUNT_THLD << JRCFG_ICDCT_SHIFT) |
          (JOBR_INTC_TIME_THLD << JRCFG_ICTT_SHIFT));

    jrp->assign = JOBR_UNASSIGNED;
    return 0;
}

/*
 * Shutdown JobR independent of platform property code
 */
int caam_jr_shutdown(struct device *dev)
{
    struct caam_drv_private_jr *jrp = dev_get_drvdata(dev);
    dma_addr_t inpbusaddr, outbusaddr;
    int ret;

    ret = caam_reset_hw_jr(dev);

    tasklet_kill(&jrp->irqtask);

    /* Release interrupt */
    free_irq(jrp->irq, dev);

    /* Free rings */
    inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
    outbusaddr = rd_reg64(&jrp->rregs->outring_base);
    dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
              jrp->inpring, inpbusaddr);
    dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
              jrp->outring, outbusaddr);
    kfree(jrp->entinfo);

    return ret;
}

/*
 * Probe routine for each detected JobR subsystem. It assumes that
 * property detection was picked up externally.
 */
int caam_jr_probe(struct platform_device *pdev, struct device_node *np,
          int ring)
{
    struct device *ctrldev, *jrdev;
    struct platform_device *jr_pdev;
    struct caam_drv_private *ctrlpriv;
    struct caam_drv_private_jr *jrpriv;
    u32 *jroffset;
    int error;

    ctrldev = &pdev->dev;
    ctrlpriv = dev_get_drvdata(ctrldev);

    jrpriv = kmalloc(sizeof(struct caam_drv_private_jr),
             GFP_KERNEL);
    if (jrpriv == NULL) {
        dev_err(ctrldev, "can't alloc private mem for job ring %d\n",
            ring);
        return -ENOMEM;
    }
    jrpriv->parentdev = ctrldev; /* point back to parent */
    jrpriv->ridx = ring; /* save ring identity relative to detection */

    /*
     * Derive a pointer to the detected JobRs regs
     * Driver has already iomapped the entire space, we just
     * need to add in the offset to this JobR. Don't know if I
     * like this long-term, but it'll run
     */
    jroffset = (u32 *)of_get_property(np, "reg", NULL);
    jrpriv->rregs = (struct caam_job_ring __iomem *)((void *)ctrlpriv->ctrl
                             + *jroffset);

    /* Build a local dev for each detected queue */
    jr_pdev = of_platform_device_create(np, NULL, ctrldev);
    if (jr_pdev == NULL) {
        kfree(jrpriv);
        return -EINVAL;
    }
    jrdev = &jr_pdev->dev;
    dev_set_drvdata(jrdev, jrpriv);
    ctrlpriv->jrdev[ring] = jrdev;

    if (sizeof(dma_addr_t) == sizeof(u64))
        if (of_device_is_compatible(np, "fsl,sec-v5.0-job-ring"))
            dma_set_mask(jrdev, DMA_BIT_MASK(40));
        else
            dma_set_mask(jrdev, DMA_BIT_MASK(36));
    else
        dma_set_mask(jrdev, DMA_BIT_MASK(32));

    /* Identify the interrupt */
    jrpriv->irq = of_irq_to_resource(np, 0, NULL);

    /* Now do the platform independent part */
    error = caam_jr_init(jrdev); /* now turn on hardware */
    if (error) {
        kfree(jrpriv);
        return error;
    }

    return error;
}