/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright 2025 Oxide Computer Company
 */

#include <sys/types.h>
#include <sys/file.h>
#include <sys/errno.h>
#include <sys/open.h>
#include <sys/cred.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/policy.h>
#include <sys/processor.h>
#include <sys/kmem.h>
#include <sys/modctl.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

#include <sys/auxv.h>
#include <sys/ucode.h>
#include <sys/systeminfo.h>
#include <sys/x86_archext.h>

static dev_info_t *ucode_devi;
static uint32_t ucode_max_combined_size;
static kmutex_t ucode_update_lock;

static int
ucode_getinfo(dev_info_t *devi, ddi_info_cmd_t cmd, void *arg, void **result)
{
        switch (cmd) {
        case DDI_INFO_DEVT2DEVINFO:
        case DDI_INFO_DEVT2INSTANCE:
                break;
        default:
                return (DDI_FAILURE);
        }

        switch (getminor((dev_t)arg)) {
        case UCODE_MINOR:
                break;
        default:
                return (DDI_FAILURE);
        }

        if (cmd == DDI_INFO_DEVT2INSTANCE)
                *result = 0;
        else
                *result = ucode_devi;
        return (DDI_SUCCESS);
}

static int
ucode_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
        ASSERT(cmd != DDI_RESUME);

        switch (cmd) {
        case DDI_RESUME:
                return (DDI_SUCCESS);

        case DDI_ATTACH:
                ucode_devi = devi;
                ucode_max_combined_size = UCODE_MAX_COMBINED_SIZE;

                if (ddi_create_minor_node(devi, UCODE_NODE_NAME, S_IFCHR,
                    UCODE_MINOR, DDI_PSEUDO, 0) != DDI_SUCCESS) {
                        cmn_err(CE_WARN, "%s: Unable to create minor node",
                            UCODE_NODE_NAME);
                        return (DDI_FAILURE);
                }
                ddi_report_dev(devi);
                return (DDI_SUCCESS);

        default:
                return (DDI_FAILURE);
        }
}

static int
ucode_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
        /*
         * The power management and DR framework should never invoke this
         * driver with DDI_SUSPEND because the ucode pseudo device does not
         * have a reg property or hardware binding.  However, we will return
         * DDI_SUCCESS so that in the unlikely event that it does get
         * called, the system will still suspend and resume.
         */
        ASSERT(cmd != DDI_SUSPEND);

        switch (cmd) {
        case DDI_SUSPEND:
                return (DDI_SUCCESS);

        case DDI_DETACH:
                ddi_remove_minor_node(devi, NULL);
                ucode_devi = NULL;
                return (DDI_SUCCESS);

        default:
                return (DDI_FAILURE);
        }
}

static int
ucode_open(dev_t *dev, int flag, int otyp, cred_t *cr)
{
        return (getminor(*dev) == UCODE_MINOR ? 0 : ENXIO);
}

static int
ucode_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *cr, int *rval)
{
        switch (cmd) {
        case UCODE_GET_VERSION: {
                int size;
                uint32_t *revp, *rev_array;
                size_t bufsz = NCPU * sizeof (*revp);
                ucode_errno_t rc = EM_OK;

                STRUCT_DECL(ucode_get_rev_struct, h);
                STRUCT_INIT(h, mode);
                if (ddi_copyin((void *)arg,
                    STRUCT_BUF(h), STRUCT_SIZE(h), mode))
                        return (EFAULT);

                if ((size = STRUCT_FGET(h, ugv_size)) > NCPU || size < 0)
                        return (EINVAL);

                if (size == 0)
                        return (0);

                if ((rev_array = STRUCT_FGETP(h, ugv_rev)) == NULL)
                        return (EINVAL);

                size *= sizeof (uint32_t);

                /* Can't rely on caller for kernel's buffer size. */
                revp = kmem_zalloc(bufsz, KM_SLEEP);
                if (ddi_copyin((void *)rev_array, revp, size, mode) != 0) {
                        kmem_free(revp, bufsz);
                        return (EINVAL);
                }

                rc = ucode_get_rev(revp);

                STRUCT_FSET(h, ugv_errno, rc);

                if (ddi_copyout(revp, (void *)rev_array, size, mode) != 0) {
                        kmem_free(revp, bufsz);
                        return (EFAULT);
                }

                kmem_free(revp, bufsz);

                if (ddi_copyout(STRUCT_BUF(h), (void *)arg,
                    STRUCT_SIZE(h), mode))
                        return (EFAULT);

                return (0);
        }

        case UCODE_UPDATE: {
                size_t size;
                uint8_t *ucodep, *uw_ucode;
                ucode_errno_t rc = EM_OK;

                /*
                 * Requires all privilege.
                 */
                if (cr && secpolicy_ucode_update(cr))
                        return (EPERM);

                STRUCT_DECL(ucode_write_struct, h);

                STRUCT_INIT(h, mode);
                if (ddi_copyin((void *)arg, STRUCT_BUF(h), STRUCT_SIZE(h),
                    mode))
                        return (EFAULT);

                /*
                 * We allow the size of the combined microcode file to be up to
                 * ucode_max_combined_size.  It is initialized to
                 * UCODE_MAX_COMBINED_SIZE, and can be patched if necessary.
                 */
                size = STRUCT_FGET(h, uw_size);
                if (size > ucode_max_combined_size || size == 0)
                        return (EINVAL);

                if ((uw_ucode = STRUCT_FGETP(h, uw_ucode)) == NULL)
                        return (EINVAL);

                ucodep = kmem_zalloc(size, KM_SLEEP);
                if (ddi_copyin((void *)uw_ucode, ucodep, size, mode) != 0) {
                        kmem_free(ucodep, size);
                        return (EFAULT);
                }

                if ((rc = ucode_validate(ucodep, size)) != EM_OK) {
                        kmem_free(ucodep, size);
                        STRUCT_FSET(h, uw_errno, rc);
                        if (ddi_copyout(STRUCT_BUF(h), (void *)arg,
                            STRUCT_SIZE(h), mode))
                                return (EFAULT);
                        return (0);
                }

                mutex_enter(&ucode_update_lock);
                rc = ucode_update(ucodep, size);
                mutex_exit(&ucode_update_lock);

                kmem_free(ucodep, size);

                STRUCT_FSET(h, uw_errno, rc);
                if (ddi_copyout(STRUCT_BUF(h), (void *)arg,
                    STRUCT_SIZE(h), mode))
                        return (EFAULT);

                /*
                 * Even if rc is not EM_OK, it is a successful operation
                 * from ioctl()'s perspective.  We return the detailed error
                 * code via the ucode_write_struct data structure.
                 */
                return (0);
        }


        default:
                return (ENOTTY);
        }
}

static struct cb_ops ucode_cb_ops = {
        ucode_open,
        nulldev,        /* close */
        nodev,          /* strategy */
        nodev,          /* print */
        nodev,          /* dump */
        nodev,          /* read */
        nodev,          /* write */
        ucode_ioctl,
        nodev,          /* devmap */
        nodev,          /* mmap */
        nodev,          /* segmap */
        nochpoll,       /* poll */
        ddi_prop_op,
        NULL,
        D_64BIT | D_NEW | D_MP
};

static struct dev_ops ucode_dv_ops = {
        DEVO_REV,
        0,
        ucode_getinfo,
        nulldev,                /* identify */
        nulldev,                /* probe */
        ucode_attach,
        ucode_detach,
        nodev,                  /* reset */
        &ucode_cb_ops,
        (struct bus_ops *)0,
        NULL,                   /* power */
        ddi_quiesce_not_needed,         /* quiesce */
};

static struct modldrv modldrv = {
        &mod_driverops,
        "ucode driver",
        &ucode_dv_ops
};

static struct modlinkage modl = {
        MODREV_1,
        &modldrv
};

int
_init(void)
{
        int rc;

        if ((rc = mod_install(&modl)) != 0)
                return (rc);

        mutex_init(&ucode_update_lock, NULL, MUTEX_DRIVER, NULL);

        return (0);
}

int
_fini(void)
{
        int rc;

        if ((rc = mod_remove(&modl)) != 0)
                return (rc);

        mutex_destroy(&ucode_update_lock);

        return (0);
}

int
_info(struct modinfo *modinfo)
{
        return (mod_info(&modl, modinfo));
}