Linux 3.3-rc6

[linux/fpc-iii.git] / drivers / crypto / caam / jr.c

/*
 * CAAM/SEC 4.x transport/backend driver
 * JobR backend functionality
 *
 * Copyright 2008-2011 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[smp_processor_id()]);
        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;
        unsigned long flags;

        spin_lock_irqsave(&jrp->outlock, flags);

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

        while (CIRC_CNT(head, tail, JOBR_DEPTH) >= 1 &&
               rd_reg32(&jrp->rregs->outring_used)) {

                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;

                smp_mb();

                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;
                }

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

                spin_unlock_irqrestore(&jrp->outlock, flags);

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

                spin_lock_irqsave(&jrp->outlock, flags);

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

        spin_unlock_irqrestore(&jrp->outlock, flags);

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

/**
 * caam_jr_register() - Alloc a ring for someone to use as needed. Returns
 * an ordinal of the rings allocated, else returns -ENODEV if no rings
 * are available.
 * @ctrldev: points to the controller level dev (parent) that
 *           owns rings available for use.
 * @dev:     points to where a pointer to the newly allocated queue's
 *           dev can be written to if successful.
 **/
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;
        unsigned long flags;
        int ring;

        /* Lock, if free ring - assign, unlock */
        spin_lock_irqsave(&ctrlpriv->jr_alloc_lock, flags);
        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_irqrestore(&ctrlpriv->jr_alloc_lock, flags);
                        return ring;
                }
        }

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

        return -ENODEV;
}
EXPORT_SYMBOL(caam_jr_register);

/**
 * caam_jr_deregister() - Deregister an API and release the queue.
 * Returns 0 if OK, -EBUSY if queue still contains pending entries
 * or unprocessed results at the time of the call
 * @dev     - points to the dev that identifies the queue to
 *            be released.
 **/
int caam_jr_deregister(struct device *rdev)
{
        struct caam_drv_private_jr *jrpriv = dev_get_drvdata(rdev);
        struct caam_drv_private *ctrlpriv;
        unsigned long flags;

        /* 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_irqsave(&ctrlpriv->jr_alloc_lock, flags);
        jrpriv->assign = JOBR_UNASSIGNED;
        spin_unlock_irqrestore(&ctrlpriv->jr_alloc_lock, flags);

        return 0;
}
EXPORT_SYMBOL(caam_jr_deregister);

/**
 * caam_jr_enqueue() - Enqueue a job descriptor head. Returns 0 if OK,
 * -EBUSY if the queue is full, -EIO if it cannot map the caller's
 * descriptor.
 * @dev:  device of the job ring to be used. This device should have
 *        been assigned prior by caam_jr_register().
 * @desc: points to a job descriptor that execute our request. All
 *        descriptors (and all referenced data) must be in a DMAable
 *        region, and all data references must be physical addresses
 *        accessible to CAAM (i.e. within a PAMU window granted
 *        to it).
 * @cbk:  pointer to a callback function to be invoked upon completion
 *        of this request. This has the form:
 *        callback(struct device *dev, u32 *desc, u32 stat, void *arg)
 *        where:
 *        @dev:    contains the job ring device that processed this
 *                 response.
 *        @desc:   descriptor that initiated the request, same as
 *                 "desc" being argued to caam_jr_enqueue().
 *        @status: untranslated status received from CAAM. See the
 *                 reference manual for a detailed description of
 *                 error meaning, or see the JRSTA definitions in the
 *                 register header file
 *        @areq:   optional pointer to an argument passed with the
 *                 original request
 * @areq: optional pointer to a user argument for use at callback
 *        time.
 **/
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;
        unsigned long flags;
        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_irqsave(&jrp->inplock, flags);

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

        if (!rd_reg32(&jrp->rregs->inpring_avail) ||
            CIRC_SPACE(head, tail, JOBR_DEPTH) <= 0) {
                spin_unlock_irqrestore(&jrp->inplock, flags);
                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);

        wmb();

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

        spin_unlock_irqrestore(&jrp->inplock, flags);

        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);

        /* Connect job ring interrupt handler. */
        for_each_possible_cpu(i)
                tasklet_init(&jrp->irqtask[i], caam_jr_dequeue,
                             (unsigned long)dev);

        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 = kzalloc(sizeof(dma_addr_t) * JOBR_DEPTH,
                               GFP_KERNEL | GFP_DMA);
        jrp->outring = kzalloc(sizeof(struct jr_outentry) *
                               JOBR_DEPTH, GFP_KERNEL | GFP_DMA);

        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 */
        inpbusaddr = dma_map_single(dev, jrp->inpring,
                                    sizeof(u32 *) * JOBR_DEPTH,
                                    DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, inpbusaddr)) {
                dev_err(dev, "caam_jr_init(): can't map input ring\n");
                kfree(jrp->inpring);
                kfree(jrp->outring);
                kfree(jrp->entinfo);
                return -EIO;
        }

        outbusaddr = dma_map_single(dev, jrp->outring,
                                    sizeof(struct jr_outentry) * JOBR_DEPTH,
                                    DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, outbusaddr)) {
                dev_err(dev, "caam_jr_init(): can't map output ring\n");
                        dma_unmap_single(dev, inpbusaddr,
                                         sizeof(u32 *) * JOBR_DEPTH,
                                         DMA_BIDIRECTIONAL);
                kfree(jrp->inpring);
                kfree(jrp->outring);
                kfree(jrp->entinfo);
                return -EIO;
        }

        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, i;

        ret = caam_reset_hw_jr(dev);

        for_each_possible_cpu(i)
                tasklet_kill(&jrp->irqtask[i]);

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

        /* Free rings */
        inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
        outbusaddr = rd_reg64(&jrp->rregs->outring_base);
        dma_unmap_single(dev, outbusaddr,
                         sizeof(struct jr_outentry) * JOBR_DEPTH,
                         DMA_BIDIRECTIONAL);
        dma_unmap_single(dev, inpbusaddr, sizeof(u32 *) * JOBR_DEPTH,
                         DMA_BIDIRECTIONAL);
        kfree(jrp->outring);
        kfree(jrp->inpring);
        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;

        /* 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;
}