ctrl.c

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/*
 * CAAM control-plane driver backend
 * Controller-level driver, kernel property detection, initialization
 *
 * Copyright 2008-2012 Freescale Semiconductor, Inc.
 */

#include "compat.h"
#include "regs.h"
#include "intern.h"
#include "jr.h"
#include "desc_constr.h"
#include "error.h"
#include "ctrl.h"

static int caam_remove(struct platform_device *pdev)
{
    struct device *ctrldev;
    struct caam_drv_private *ctrlpriv;
    struct caam_drv_private_jr *jrpriv;
    struct caam_full __iomem *topregs;
    int ring, ret = 0;

    ctrldev = &pdev->dev;
    ctrlpriv = dev_get_drvdata(ctrldev);
    topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;

    /* shut down JobRs */
    for (ring = 0; ring < ctrlpriv->total_jobrs; ring++) {
        ret |= caam_jr_shutdown(ctrlpriv->jrdev[ring]);
        jrpriv = dev_get_drvdata(ctrlpriv->jrdev[ring]);
        irq_dispose_mapping(jrpriv->irq);
    }

    /* Shut down debug views */
#ifdef CONFIG_DEBUG_FS
    debugfs_remove_recursive(ctrlpriv->dfs_root);
#endif

    /* Unmap controller region */
    iounmap(&topregs->ctrl);

    kfree(ctrlpriv->jrdev);
    kfree(ctrlpriv);

    return ret;
}

/*
 * Descriptor to instantiate RNG State Handle 0 in normal mode and
 * load the JDKEK, TDKEK and TDSK registers
 */
static void build_instantiation_desc(u32 *desc)
{
    u32 *jump_cmd;

    init_job_desc(desc, 0);

    /* INIT RNG in non-test mode */
    append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
             OP_ALG_AS_INIT);

    /* wait for done */
    jump_cmd = append_jump(desc, JUMP_CLASS_CLASS1);
    set_jump_tgt_here(desc, jump_cmd);

    /*
     * load 1 to clear written reg:
     * resets the done interrrupt and returns the RNG to idle.
     */
    append_load_imm_u32(desc, 1, LDST_SRCDST_WORD_CLRW);

    /* generate secure keys (non-test) */
    append_operation(desc, OP_TYPE_CLASS1_ALG | OP_ALG_ALGSEL_RNG |
             OP_ALG_RNG4_SK);
}

struct instantiate_result {
    struct completion completion;
    int err;
};

static void rng4_init_done(struct device *dev, u32 *desc, u32 err,
               void *context)
{
    struct instantiate_result *instantiation = context;

    if (err) {
        char tmp[CAAM_ERROR_STR_MAX];

        dev_err(dev, "%08x: %s\n", err, caam_jr_strstatus(tmp, err));
    }

    instantiation->err = err;
    complete(&instantiation->completion);
}

static int instantiate_rng(struct device *jrdev)
{
    struct instantiate_result instantiation;

    dma_addr_t desc_dma;
    u32 *desc;
    int ret;

    desc = kmalloc(CAAM_CMD_SZ * 6, GFP_KERNEL | GFP_DMA);
    if (!desc) {
        dev_err(jrdev, "cannot allocate RNG init descriptor memory\n");
        return -ENOMEM;
    }

    build_instantiation_desc(desc);
    desc_dma = dma_map_single(jrdev, desc, desc_bytes(desc), DMA_TO_DEVICE);
    init_completion(&instantiation.completion);
    ret = caam_jr_enqueue(jrdev, desc, rng4_init_done, &instantiation);
    if (!ret) {
        wait_for_completion_interruptible(&instantiation.completion);
        ret = instantiation.err;
        if (ret)
            dev_err(jrdev, "unable to instantiate RNG\n");
    }

    dma_unmap_single(jrdev, desc_dma, desc_bytes(desc), DMA_TO_DEVICE);

    kfree(desc);

    return ret;
}

/*
 * By default, the TRNG runs for 200 clocks per sample;
 * 1600 clocks per sample generates better entropy.
 */
static void kick_trng(struct platform_device *pdev)
{
    struct device *ctrldev = &pdev->dev;
    struct caam_drv_private *ctrlpriv = dev_get_drvdata(ctrldev);
    struct caam_full __iomem *topregs;
    struct rng4tst __iomem *r4tst;
    u32 val;

    topregs = (struct caam_full __iomem *)ctrlpriv->ctrl;
    r4tst = &topregs->ctrl.r4tst[0];

    /* put RNG4 into program mode */
    setbits32(&r4tst->rtmctl, RTMCTL_PRGM);
    /* 1600 clocks per sample */
    val = rd_reg32(&r4tst->rtsdctl);
    val = (val & ~RTSDCTL_ENT_DLY_MASK) | (1600 << RTSDCTL_ENT_DLY_SHIFT);
    wr_reg32(&r4tst->rtsdctl, val);
    /* min. freq. count */
    wr_reg32(&r4tst->rtfrqmin, 400);
    /* max. freq. count */
    wr_reg32(&r4tst->rtfrqmax, 6400);
    /* put RNG4 into run mode */
    clrbits32(&r4tst->rtmctl, RTMCTL_PRGM);
}

int caam_get_era(u64 caam_id)
{
    struct sec_vid *sec_vid = (struct sec_vid *)&caam_id;
    static const struct {
        u16 ip_id;
        u8 maj_rev;
        u8 era;
    } caam_eras[] = {
        {0x0A10, 1, 1},
        {0x0A10, 2, 2},
        {0x0A12, 1, 3},
        {0x0A14, 1, 3},
        {0x0A14, 2, 4},
        {0x0A16, 1, 4},
        {0x0A11, 1, 4}
    };
    int i;

    for (i = 0; i < ARRAY_SIZE(caam_eras); i++)
        if (caam_eras[i].ip_id == sec_vid->ip_id &&
            caam_eras[i].maj_rev == sec_vid->maj_rev)
                return caam_eras[i].era;

    return -ENOTSUPP;
}
EXPORT_SYMBOL(caam_get_era);

/* Probe routine for CAAM top (controller) level */
static int caam_probe(struct platform_device *pdev)
{
    int ret, ring, rspec;
    u64 caam_id;
    struct device *dev;
    struct device_node *nprop, *np;
    struct caam_ctrl __iomem *ctrl;
    struct caam_full __iomem *topregs;
    struct caam_drv_private *ctrlpriv;
#ifdef CONFIG_DEBUG_FS
    struct caam_perfmon *perfmon;
#endif

    ctrlpriv = kzalloc(sizeof(struct caam_drv_private), GFP_KERNEL);
    if (!ctrlpriv)
        return -ENOMEM;

    dev = &pdev->dev;
    dev_set_drvdata(dev, ctrlpriv);
    ctrlpriv->pdev = pdev;
    nprop = pdev->dev.of_node;

    /* Get configuration properties from device tree */
    /* First, get register page */
    ctrl = of_iomap(nprop, 0);
    if (ctrl == NULL) {
        dev_err(dev, "caam: of_iomap() failed\n");
        return -ENOMEM;
    }
    ctrlpriv->ctrl = (struct caam_ctrl __force *)ctrl;

    /* topregs used to derive pointers to CAAM sub-blocks only */
    topregs = (struct caam_full __iomem *)ctrl;

    /* Get the IRQ of the controller (for security violations only) */
    ctrlpriv->secvio_irq = of_irq_to_resource(nprop, 0, NULL);

    /*
     * Enable DECO watchdogs and, if this is a PHYS_ADDR_T_64BIT kernel,
     * long pointers in master configuration register
     */
    setbits32(&topregs->ctrl.mcr, MCFGR_WDENABLE |
          (sizeof(dma_addr_t) == sizeof(u64) ? MCFGR_LONG_PTR : 0));

    if (sizeof(dma_addr_t) == sizeof(u64))
        if (of_device_is_compatible(nprop, "fsl,sec-v5.0"))
            dma_set_mask(dev, DMA_BIT_MASK(40));
        else
            dma_set_mask(dev, DMA_BIT_MASK(36));
    else
        dma_set_mask(dev, DMA_BIT_MASK(32));

    /*
     * Detect and enable JobRs
     * First, find out how many ring spec'ed, allocate references
     * for all, then go probe each one.
     */
    rspec = 0;
    for_each_compatible_node(np, NULL, "fsl,sec-v4.0-job-ring")
        rspec++;
    if (!rspec) {
        /* for backward compatible with device trees */
        for_each_compatible_node(np, NULL, "fsl,sec4.0-job-ring")
            rspec++;
    }

    ctrlpriv->jrdev = kzalloc(sizeof(struct device *) * rspec, GFP_KERNEL);
    if (ctrlpriv->jrdev == NULL) {
        iounmap(&topregs->ctrl);
        return -ENOMEM;
    }

    ring = 0;
    ctrlpriv->total_jobrs = 0;
    for_each_compatible_node(np, NULL, "fsl,sec-v4.0-job-ring") {
        caam_jr_probe(pdev, np, ring);
        ctrlpriv->total_jobrs++;
        ring++;
    }
    if (!ring) {
        for_each_compatible_node(np, NULL, "fsl,sec4.0-job-ring") {
            caam_jr_probe(pdev, np, ring);
            ctrlpriv->total_jobrs++;
            ring++;
        }
    }

    /* Check to see if QI present. If so, enable */
    ctrlpriv->qi_present = !!(rd_reg64(&topregs->ctrl.perfmon.comp_parms) &
                  CTPR_QI_MASK);
    if (ctrlpriv->qi_present) {
        ctrlpriv->qi = (struct caam_queue_if __force *)&topregs->qi;
        /* This is all that's required to physically enable QI */
        wr_reg32(&topregs->qi.qi_control_lo, QICTL_DQEN);
    }

    /* If no QI and no rings specified, quit and go home */
    if ((!ctrlpriv->qi_present) && (!ctrlpriv->total_jobrs)) {
        dev_err(dev, "no queues configured, terminating\n");
        caam_remove(pdev);
        return -ENOMEM;
    }

    /*
     * RNG4 based SECs (v5+) need special initialization prior
     * to executing any descriptors
     */
    if (of_device_is_compatible(nprop, "fsl,sec-v5.0")) {
        kick_trng(pdev);
        ret = instantiate_rng(ctrlpriv->jrdev[0]);
        if (ret) {
            caam_remove(pdev);
            return ret;
        }
    }

    /* NOTE: RTIC detection ought to go here, around Si time */

    /* Initialize queue allocator lock */
    spin_lock_init(&ctrlpriv->jr_alloc_lock);

    caam_id = rd_reg64(&topregs->ctrl.perfmon.caam_id);

    /* Report "alive" for developer to see */
    dev_info(dev, "device ID = 0x%016llx (Era %d)\n", caam_id,
         caam_get_era(caam_id));
    dev_info(dev, "job rings = %d, qi = %d\n",
         ctrlpriv->total_jobrs, ctrlpriv->qi_present);

#ifdef CONFIG_DEBUG_FS
    /*
     * FIXME: needs better naming distinction, as some amalgamation of
     * "caam" and nprop->full_name. The OF name isn't distinctive,
     * but does separate instances
     */
    perfmon = (struct caam_perfmon __force *)&ctrl->perfmon;

    ctrlpriv->dfs_root = debugfs_create_dir("caam", NULL);
    ctrlpriv->ctl = debugfs_create_dir("ctl", ctrlpriv->dfs_root);

    /* Controller-level - performance monitor counters */
    ctrlpriv->ctl_rq_dequeued =
        debugfs_create_u64("rq_dequeued",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->req_dequeued);
    ctrlpriv->ctl_ob_enc_req =
        debugfs_create_u64("ob_rq_encrypted",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->ob_enc_req);
    ctrlpriv->ctl_ib_dec_req =
        debugfs_create_u64("ib_rq_decrypted",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->ib_dec_req);
    ctrlpriv->ctl_ob_enc_bytes =
        debugfs_create_u64("ob_bytes_encrypted",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->ob_enc_bytes);
    ctrlpriv->ctl_ob_prot_bytes =
        debugfs_create_u64("ob_bytes_protected",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->ob_prot_bytes);
    ctrlpriv->ctl_ib_dec_bytes =
        debugfs_create_u64("ib_bytes_decrypted",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->ib_dec_bytes);
    ctrlpriv->ctl_ib_valid_bytes =
        debugfs_create_u64("ib_bytes_validated",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->ib_valid_bytes);

    /* Controller level - global status values */
    ctrlpriv->ctl_faultaddr =
        debugfs_create_u64("fault_addr",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->faultaddr);
    ctrlpriv->ctl_faultdetail =
        debugfs_create_u32("fault_detail",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->faultdetail);
    ctrlpriv->ctl_faultstatus =
        debugfs_create_u32("fault_status",
                   S_IRUSR | S_IRGRP | S_IROTH,
                   ctrlpriv->ctl, &perfmon->status);

    /* Internal covering keys (useful in non-secure mode only) */
    ctrlpriv->ctl_kek_wrap.data = &ctrlpriv->ctrl->kek[0];
    ctrlpriv->ctl_kek_wrap.size = KEK_KEY_SIZE * sizeof(u32);
    ctrlpriv->ctl_kek = debugfs_create_blob("kek",
                        S_IRUSR |
                        S_IRGRP | S_IROTH,
                        ctrlpriv->ctl,
                        &ctrlpriv->ctl_kek_wrap);

    ctrlpriv->ctl_tkek_wrap.data = &ctrlpriv->ctrl->tkek[0];
    ctrlpriv->ctl_tkek_wrap.size = KEK_KEY_SIZE * sizeof(u32);
    ctrlpriv->ctl_tkek = debugfs_create_blob("tkek",
                         S_IRUSR |
                         S_IRGRP | S_IROTH,
                         ctrlpriv->ctl,
                         &ctrlpriv->ctl_tkek_wrap);

    ctrlpriv->ctl_tdsk_wrap.data = &ctrlpriv->ctrl->tdsk[0];
    ctrlpriv->ctl_tdsk_wrap.size = KEK_KEY_SIZE * sizeof(u32);
    ctrlpriv->ctl_tdsk = debugfs_create_blob("tdsk",
                         S_IRUSR |
                         S_IRGRP | S_IROTH,
                         ctrlpriv->ctl,
                         &ctrlpriv->ctl_tdsk_wrap);
#endif
    return 0;
}

static struct of_device_id caam_match[] = {
    {
        .compatible = "fsl,sec-v4.0",
    },
    {
        .compatible = "fsl,sec4.0",
    },
    {},
};
MODULE_DEVICE_TABLE(of, caam_match);

static struct platform_driver caam_driver = {
    .driver = {
        .name = "caam",
        .owner = THIS_MODULE,
        .of_match_table = caam_match,
    },
    .probe       = caam_probe,
    .remove      = __devexit_p(caam_remove),
};

module_platform_driver(caam_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("FSL CAAM request backend");
MODULE_AUTHOR("Freescale Semiconductor - NMG/STC");