nx.c

Go to the documentation of this file.

#include <crypto/internal/hash.h>
#include <crypto/hash.h>
#include <crypto/aes.h>
#include <crypto/sha.h>
#include <crypto/algapi.h>
#include <crypto/scatterwalk.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include <linux/device.h>
#include <linux/of.h>
#include <asm/pSeries_reconfig.h>
#include <asm/hvcall.h>
#include <asm/vio.h>

#include "nx_csbcpb.h"
#include "nx.h"


int nx_hcall_sync(struct nx_crypto_ctx *nx_ctx,
          struct vio_pfo_op    *op,
          u32                   may_sleep)
{
    int rc, retries = 10;
    struct vio_dev *viodev = nx_driver.viodev;

    atomic_inc(&(nx_ctx->stats->sync_ops));

    do {
        rc = vio_h_cop_sync(viodev, op);
    } while ((rc == -EBUSY && !may_sleep && retries--) ||
             (rc == -EBUSY && may_sleep && cond_resched()));

    if (rc) {
        dev_dbg(&viodev->dev, "vio_h_cop_sync failed: rc: %d "
            "hcall rc: %ld\n", rc, op->hcall_err);
        atomic_inc(&(nx_ctx->stats->errors));
        atomic_set(&(nx_ctx->stats->last_error), op->hcall_err);
        atomic_set(&(nx_ctx->stats->last_error_pid), current->pid);
    }

    return rc;
}

struct nx_sg *nx_build_sg_list(struct nx_sg *sg_head,
                   u8           *start_addr,
                   unsigned int  len,
                   u32           sgmax)
{
    unsigned int sg_len = 0;
    struct nx_sg *sg;
    u64 sg_addr = (u64)start_addr;
    u64 end_addr;

    /* determine the start and end for this address range - slightly
     * different if this is in VMALLOC_REGION */
    if (is_vmalloc_addr(start_addr))
        sg_addr = page_to_phys(vmalloc_to_page(start_addr))
              + offset_in_page(sg_addr);
    else
        sg_addr = __pa(sg_addr);

    end_addr = sg_addr + len;

    /* each iteration will write one struct nx_sg element and add the
     * length of data described by that element to sg_len. Once @len bytes
     * have been described (or @sgmax elements have been written), the
     * loop ends. min_t is used to ensure @end_addr falls on the same page
     * as sg_addr, if not, we need to create another nx_sg element for the
     * data on the next page */
    for (sg = sg_head; sg_len < len; sg++) {
        sg->addr = sg_addr;
        sg_addr = min_t(u64, NX_PAGE_NUM(sg_addr + NX_PAGE_SIZE), end_addr);
        sg->len = sg_addr - sg->addr;
        sg_len += sg->len;

        if ((sg - sg_head) == sgmax) {
            pr_err("nx: scatter/gather list overflow, pid: %d\n",
                   current->pid);
            return NULL;
        }
    }

    /* return the moved sg_head pointer */
    return sg;
}

struct nx_sg *nx_walk_and_build(struct nx_sg       *nx_dst,
                unsigned int        sglen,
                struct scatterlist *sg_src,
                unsigned int        start,
                unsigned int        src_len)
{
    struct scatter_walk walk;
    struct nx_sg *nx_sg = nx_dst;
    unsigned int n, offset = 0, len = src_len;
    char *dst;

    /* we need to fast forward through @start bytes first */
    for (;;) {
        scatterwalk_start(&walk, sg_src);

        if (start < offset + sg_src->length)
            break;

        offset += sg_src->length;
        sg_src = scatterwalk_sg_next(sg_src);
    }

    /* start - offset is the number of bytes to advance in the scatterlist
     * element we're currently looking at */
    scatterwalk_advance(&walk, start - offset);

    while (len && nx_sg) {
        n = scatterwalk_clamp(&walk, len);
        if (!n) {
            scatterwalk_start(&walk, sg_next(walk.sg));
            n = scatterwalk_clamp(&walk, len);
        }
        dst = scatterwalk_map(&walk);

        nx_sg = nx_build_sg_list(nx_sg, dst, n, sglen);
        len -= n;

        scatterwalk_unmap(dst);
        scatterwalk_advance(&walk, n);
        scatterwalk_done(&walk, SCATTERWALK_FROM_SG, len);
    }

    /* return the moved destination pointer */
    return nx_sg;
}

int nx_build_sg_lists(struct nx_crypto_ctx  *nx_ctx,
              struct blkcipher_desc *desc,
              struct scatterlist    *dst,
              struct scatterlist    *src,
              unsigned int           nbytes,
              u8                    *iv)
{
    struct nx_sg *nx_insg = nx_ctx->in_sg;
    struct nx_sg *nx_outsg = nx_ctx->out_sg;
    struct blkcipher_walk walk;
    int rc;

    blkcipher_walk_init(&walk, dst, src, nbytes);
    rc = blkcipher_walk_virt_block(desc, &walk, AES_BLOCK_SIZE);
    if (rc)
        goto out;

    if (iv)
        memcpy(iv, walk.iv, AES_BLOCK_SIZE);

    while (walk.nbytes) {
        nx_insg = nx_build_sg_list(nx_insg, walk.src.virt.addr,
                       walk.nbytes, nx_ctx->ap->sglen);
        nx_outsg = nx_build_sg_list(nx_outsg, walk.dst.virt.addr,
                        walk.nbytes, nx_ctx->ap->sglen);

        rc = blkcipher_walk_done(desc, &walk, 0);
        if (rc)
            break;
    }

    if (walk.nbytes) {
        nx_insg = nx_build_sg_list(nx_insg, walk.src.virt.addr,
                       walk.nbytes, nx_ctx->ap->sglen);
        nx_outsg = nx_build_sg_list(nx_outsg, walk.dst.virt.addr,
                        walk.nbytes, nx_ctx->ap->sglen);

        rc = 0;
    }

    /* these lengths should be negative, which will indicate to phyp that
     * the input and output parameters are scatterlists, not linear
     * buffers */
    nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * sizeof(struct nx_sg);
    nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * sizeof(struct nx_sg);
out:
    return rc;
}

void nx_ctx_init(struct nx_crypto_ctx *nx_ctx, unsigned int function)
{
    memset(nx_ctx->kmem, 0, nx_ctx->kmem_len);
    nx_ctx->csbcpb->csb.valid |= NX_CSB_VALID_BIT;

    nx_ctx->op.flags = function;
    nx_ctx->op.csbcpb = __pa(nx_ctx->csbcpb);
    nx_ctx->op.in = __pa(nx_ctx->in_sg);
    nx_ctx->op.out = __pa(nx_ctx->out_sg);

    if (nx_ctx->csbcpb_aead) {
        nx_ctx->csbcpb_aead->csb.valid |= NX_CSB_VALID_BIT;

        nx_ctx->op_aead.flags = function;
        nx_ctx->op_aead.csbcpb = __pa(nx_ctx->csbcpb_aead);
        nx_ctx->op_aead.in = __pa(nx_ctx->in_sg);
        nx_ctx->op_aead.out = __pa(nx_ctx->out_sg);
    }
}

static void nx_of_update_status(struct device   *dev,
                   struct property *p,
                   struct nx_of    *props)
{
    if (!strncmp(p->value, "okay", p->length)) {
        props->status = NX_WAITING;
        props->flags |= NX_OF_FLAG_STATUS_SET;
    } else {
        dev_info(dev, "%s: status '%s' is not 'okay'\n", __func__,
             (char *)p->value);
    }
}

static void nx_of_update_sglen(struct device   *dev,
                   struct property *p,
                   struct nx_of    *props)
{
    if (p->length != sizeof(props->max_sg_len)) {
        dev_err(dev, "%s: unexpected format for "
            "ibm,max-sg-len property\n", __func__);
        dev_dbg(dev, "%s: ibm,max-sg-len is %d bytes "
            "long, expected %zd bytes\n", __func__,
            p->length, sizeof(props->max_sg_len));
        return;
    }

    props->max_sg_len = *(u32 *)p->value;
    props->flags |= NX_OF_FLAG_MAXSGLEN_SET;
}

static void nx_of_update_msc(struct device   *dev,
                 struct property *p,
                 struct nx_of    *props)
{
    struct msc_triplet *trip;
    struct max_sync_cop *msc;
    unsigned int bytes_so_far, i, lenp;

    msc = (struct max_sync_cop *)p->value;
    lenp = p->length;

    /* You can't tell if the data read in for this property is sane by its
     * size alone. This is because there are sizes embedded in the data
     * structure. The best we can do is check lengths as we parse and bail
     * as soon as a length error is detected. */
    bytes_so_far = 0;

    while ((bytes_so_far + sizeof(struct max_sync_cop)) <= lenp) {
        bytes_so_far += sizeof(struct max_sync_cop);

        trip = msc->trip;

        for (i = 0;
             ((bytes_so_far + sizeof(struct msc_triplet)) <= lenp) &&
             i < msc->triplets;
             i++) {
            if (msc->fc > NX_MAX_FC || msc->mode > NX_MAX_MODE) {
                dev_err(dev, "unknown function code/mode "
                    "combo: %d/%d (ignored)\n", msc->fc,
                    msc->mode);
                goto next_loop;
            }

            switch (trip->keybitlen) {
            case 128:
            case 160:
                props->ap[msc->fc][msc->mode][0].databytelen =
                    trip->databytelen;
                props->ap[msc->fc][msc->mode][0].sglen =
                    trip->sglen;
                break;
            case 192:
                props->ap[msc->fc][msc->mode][1].databytelen =
                    trip->databytelen;
                props->ap[msc->fc][msc->mode][1].sglen =
                    trip->sglen;
                break;
            case 256:
                if (msc->fc == NX_FC_AES) {
                    props->ap[msc->fc][msc->mode][2].
                        databytelen = trip->databytelen;
                    props->ap[msc->fc][msc->mode][2].sglen =
                        trip->sglen;
                } else if (msc->fc == NX_FC_AES_HMAC ||
                       msc->fc == NX_FC_SHA) {
                    props->ap[msc->fc][msc->mode][1].
                        databytelen = trip->databytelen;
                    props->ap[msc->fc][msc->mode][1].sglen =
                        trip->sglen;
                } else {
                    dev_warn(dev, "unknown function "
                        "code/key bit len combo"
                        ": (%u/256)\n", msc->fc);
                }
                break;
            case 512:
                props->ap[msc->fc][msc->mode][2].databytelen =
                    trip->databytelen;
                props->ap[msc->fc][msc->mode][2].sglen =
                    trip->sglen;
                break;
            default:
                dev_warn(dev, "unknown function code/key bit "
                     "len combo: (%u/%u)\n", msc->fc,
                     trip->keybitlen);
                break;
            }
next_loop:
            bytes_so_far += sizeof(struct msc_triplet);
            trip++;
        }

        msc = (struct max_sync_cop *)trip;
    }

    props->flags |= NX_OF_FLAG_MAXSYNCCOP_SET;
}

static void nx_of_init(struct device *dev, struct nx_of *props)
{
    struct device_node *base_node = dev->of_node;
    struct property *p;

    p = of_find_property(base_node, "status", NULL);
    if (!p)
        dev_info(dev, "%s: property 'status' not found\n", __func__);
    else
        nx_of_update_status(dev, p, props);

    p = of_find_property(base_node, "ibm,max-sg-len", NULL);
    if (!p)
        dev_info(dev, "%s: property 'ibm,max-sg-len' not found\n",
             __func__);
    else
        nx_of_update_sglen(dev, p, props);

    p = of_find_property(base_node, "ibm,max-sync-cop", NULL);
    if (!p)
        dev_info(dev, "%s: property 'ibm,max-sync-cop' not found\n",
             __func__);
    else
        nx_of_update_msc(dev, p, props);
}

static int nx_register_algs(void)
{
    int rc = -1;

    if (nx_driver.of.flags != NX_OF_FLAG_MASK_READY)
        goto out;

    memset(&nx_driver.stats, 0, sizeof(struct nx_stats));

    rc = NX_DEBUGFS_INIT(&nx_driver);
    if (rc)
        goto out;

    rc = crypto_register_alg(&nx_ecb_aes_alg);
    if (rc)
        goto out;

    rc = crypto_register_alg(&nx_cbc_aes_alg);
    if (rc)
        goto out_unreg_ecb;

    rc = crypto_register_alg(&nx_ctr_aes_alg);
    if (rc)
        goto out_unreg_cbc;

    rc = crypto_register_alg(&nx_ctr3686_aes_alg);
    if (rc)
        goto out_unreg_ctr;

    rc = crypto_register_alg(&nx_gcm_aes_alg);
    if (rc)
        goto out_unreg_ctr3686;

    rc = crypto_register_alg(&nx_gcm4106_aes_alg);
    if (rc)
        goto out_unreg_gcm;

    rc = crypto_register_alg(&nx_ccm_aes_alg);
    if (rc)
        goto out_unreg_gcm4106;

    rc = crypto_register_alg(&nx_ccm4309_aes_alg);
    if (rc)
        goto out_unreg_ccm;

    rc = crypto_register_shash(&nx_shash_sha256_alg);
    if (rc)
        goto out_unreg_ccm4309;

    rc = crypto_register_shash(&nx_shash_sha512_alg);
    if (rc)
        goto out_unreg_s256;

    rc = crypto_register_shash(&nx_shash_aes_xcbc_alg);
    if (rc)
        goto out_unreg_s512;

    nx_driver.of.status = NX_OKAY;

    goto out;

out_unreg_s512:
    crypto_unregister_shash(&nx_shash_sha512_alg);
out_unreg_s256:
    crypto_unregister_shash(&nx_shash_sha256_alg);
out_unreg_ccm4309:
    crypto_unregister_alg(&nx_ccm4309_aes_alg);
out_unreg_ccm:
    crypto_unregister_alg(&nx_ccm_aes_alg);
out_unreg_gcm4106:
    crypto_unregister_alg(&nx_gcm4106_aes_alg);
out_unreg_gcm:
    crypto_unregister_alg(&nx_gcm_aes_alg);
out_unreg_ctr3686:
    crypto_unregister_alg(&nx_ctr3686_aes_alg);
out_unreg_ctr:
    crypto_unregister_alg(&nx_ctr_aes_alg);
out_unreg_cbc:
    crypto_unregister_alg(&nx_cbc_aes_alg);
out_unreg_ecb:
    crypto_unregister_alg(&nx_ecb_aes_alg);
out:
    return rc;
}

static int nx_crypto_ctx_init(struct nx_crypto_ctx *nx_ctx, u32 fc, u32 mode)
{
    if (nx_driver.of.status != NX_OKAY) {
        pr_err("Attempt to initialize NX crypto context while device "
               "is not available!\n");
        return -ENODEV;
    }

    /* we need an extra page for csbcpb_aead for these modes */
    if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
        nx_ctx->kmem_len = (4 * NX_PAGE_SIZE) +
                   sizeof(struct nx_csbcpb);
    else
        nx_ctx->kmem_len = (3 * NX_PAGE_SIZE) +
                   sizeof(struct nx_csbcpb);

    nx_ctx->kmem = kmalloc(nx_ctx->kmem_len, GFP_KERNEL);
    if (!nx_ctx->kmem)
        return -ENOMEM;

    /* the csbcpb and scatterlists must be 4K aligned pages */
    nx_ctx->csbcpb = (struct nx_csbcpb *)(round_up((u64)nx_ctx->kmem,
                               (u64)NX_PAGE_SIZE));
    nx_ctx->in_sg = (struct nx_sg *)((u8 *)nx_ctx->csbcpb + NX_PAGE_SIZE);
    nx_ctx->out_sg = (struct nx_sg *)((u8 *)nx_ctx->in_sg + NX_PAGE_SIZE);

    if (mode == NX_MODE_AES_GCM || mode == NX_MODE_AES_CCM)
        nx_ctx->csbcpb_aead =
            (struct nx_csbcpb *)((u8 *)nx_ctx->out_sg +
                         NX_PAGE_SIZE);

    /* give each context a pointer to global stats and their OF
     * properties */
    nx_ctx->stats = &nx_driver.stats;
    memcpy(nx_ctx->props, nx_driver.of.ap[fc][mode],
           sizeof(struct alg_props) * 3);

    return 0;
}

/* entry points from the crypto tfm initializers */
int nx_crypto_ctx_aes_ccm_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
                  NX_MODE_AES_CCM);
}

int nx_crypto_ctx_aes_gcm_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
                  NX_MODE_AES_GCM);
}

int nx_crypto_ctx_aes_ctr_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
                  NX_MODE_AES_CTR);
}

int nx_crypto_ctx_aes_cbc_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
                  NX_MODE_AES_CBC);
}

int nx_crypto_ctx_aes_ecb_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
                  NX_MODE_AES_ECB);
}

int nx_crypto_ctx_sha_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_SHA, NX_MODE_SHA);
}

int nx_crypto_ctx_aes_xcbc_init(struct crypto_tfm *tfm)
{
    return nx_crypto_ctx_init(crypto_tfm_ctx(tfm), NX_FC_AES,
                  NX_MODE_AES_XCBC_MAC);
}

void nx_crypto_ctx_exit(struct crypto_tfm *tfm)
{
    struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(tfm);

    kzfree(nx_ctx->kmem);
    nx_ctx->csbcpb = NULL;
    nx_ctx->csbcpb_aead = NULL;
    nx_ctx->in_sg = NULL;
    nx_ctx->out_sg = NULL;
}

static int __devinit nx_probe(struct vio_dev *viodev,
                  const struct vio_device_id *id)
{
    dev_dbg(&viodev->dev, "driver probed: %s resource id: 0x%x\n",
        viodev->name, viodev->resource_id);

    if (nx_driver.viodev) {
        dev_err(&viodev->dev, "%s: Attempt to register more than one "
            "instance of the hardware\n", __func__);
        return -EINVAL;
    }

    nx_driver.viodev = viodev;

    nx_of_init(&viodev->dev, &nx_driver.of);

    return nx_register_algs();
}

static int __devexit nx_remove(struct vio_dev *viodev)
{
    dev_dbg(&viodev->dev, "entering nx_remove for UA 0x%x\n",
        viodev->unit_address);

    if (nx_driver.of.status == NX_OKAY) {
        NX_DEBUGFS_FINI(&nx_driver);

        crypto_unregister_alg(&nx_ccm_aes_alg);
        crypto_unregister_alg(&nx_ccm4309_aes_alg);
        crypto_unregister_alg(&nx_gcm_aes_alg);
        crypto_unregister_alg(&nx_gcm4106_aes_alg);
        crypto_unregister_alg(&nx_ctr_aes_alg);
        crypto_unregister_alg(&nx_ctr3686_aes_alg);
        crypto_unregister_alg(&nx_cbc_aes_alg);
        crypto_unregister_alg(&nx_ecb_aes_alg);
        crypto_unregister_shash(&nx_shash_sha256_alg);
        crypto_unregister_shash(&nx_shash_sha512_alg);
        crypto_unregister_shash(&nx_shash_aes_xcbc_alg);
    }

    return 0;
}


/* module wide initialization/cleanup */
static int __init nx_init(void)
{
    return vio_register_driver(&nx_driver.viodriver);
}

static void __exit nx_fini(void)
{
    vio_unregister_driver(&nx_driver.viodriver);
}

static struct vio_device_id nx_crypto_driver_ids[] __devinitdata = {
    { "ibm,sym-encryption-v1", "ibm,sym-encryption" },
    { "", "" }
};
MODULE_DEVICE_TABLE(vio, nx_crypto_driver_ids);

/* driver state structure */
struct nx_crypto_driver nx_driver = {
    .viodriver = {
        .id_table = nx_crypto_driver_ids,
        .probe = nx_probe,
        .remove = nx_remove,
        .name  = NX_NAME,
    },
};

module_init(nx_init);
module_exit(nx_fini);

MODULE_AUTHOR("Kent Yoder <[email protected]>");
MODULE_DESCRIPTION(NX_STRING);
MODULE_LICENSE("GPL");
MODULE_VERSION(NX_VERSION);