/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2016-2019 Ruslan Bukin <br@bsdpad.com>
 *
 * This software was developed by SRI International and the University of
 * Cambridge Computer Laboratory under DARPA/AFRL contract FA8750-10-C-0237
 * ("CTSRD"), as part of the DARPA CRASH research programme.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/epoch.h>
#include <sys/kernel.h>
#include <sys/queue.h>
#include <sys/kobj.h>
#include <sys/malloc.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

#include <machine/bus.h>

#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif

#include <dev/xdma/xdma.h>

#include <xdma_if.h>

/*
 * Multiple xDMA controllers may work with single DMA device,
 * so we have global lock for physical channel management.
 */
static struct mtx xdma_mtx;

#define XDMA_LOCK()                     mtx_lock(&xdma_mtx)
#define XDMA_UNLOCK()                   mtx_unlock(&xdma_mtx)
#define XDMA_ASSERT_LOCKED()            mtx_assert(&xdma_mtx, MA_OWNED)

#define FDT_REG_CELLS   4

#ifdef FDT
static int
xdma_get_iommu_fdt(xdma_controller_t *xdma, xdma_channel_t *xchan)
{
        struct xdma_iommu *xio;
        phandle_t node;
        pcell_t prop;
        size_t len;

        node = ofw_bus_get_node(xdma->dma_dev);
        if (OF_getproplen(node, "xdma,iommu") <= 0)
                return (0);

        len = OF_getencprop(node, "xdma,iommu", &prop, sizeof(prop));
        if (len != sizeof(prop)) {
                device_printf(xdma->dev,
                    "%s: Can't get iommu device node\n", __func__);
                return (0);
        }

        xio = &xchan->xio;
        xio->dev = OF_device_from_xref(prop);
        if (xio->dev == NULL) {
                device_printf(xdma->dev,
                    "%s: Can't get iommu device\n", __func__);
                return (0);
        }

        /* Found */
        return (1);
}
#endif

/*
 * Allocate virtual xDMA channel.
 */
xdma_channel_t *
xdma_channel_alloc(xdma_controller_t *xdma, uint32_t caps)
{
        xdma_channel_t *xchan;
        int ret;

        xchan = malloc(sizeof(xdma_channel_t), M_XDMA, M_WAITOK | M_ZERO);
        xchan->xdma = xdma;

#ifdef FDT
        /* Check if this DMA controller supports IOMMU. */
        if (xdma_get_iommu_fdt(xdma, xchan))
                caps |= XCHAN_CAP_IOMMU | XCHAN_CAP_NOSEG;
#endif

        xchan->caps = caps;

        XDMA_LOCK();

        /* Request a real channel from hardware driver. */
        ret = XDMA_CHANNEL_ALLOC(xdma->dma_dev, xchan);
        if (ret != 0) {
                device_printf(xdma->dev,
                    "%s: Can't request hardware channel.\n", __func__);
                XDMA_UNLOCK();
                free(xchan, M_XDMA);

                return (NULL);
        }

        TAILQ_INIT(&xchan->ie_handlers);

        mtx_init(&xchan->mtx_lock, "xDMA chan", NULL, MTX_DEF);
        mtx_init(&xchan->mtx_qin_lock, "xDMA qin", NULL, MTX_DEF);
        mtx_init(&xchan->mtx_qout_lock, "xDMA qout", NULL, MTX_DEF);
        mtx_init(&xchan->mtx_bank_lock, "xDMA bank", NULL, MTX_DEF);
        mtx_init(&xchan->mtx_proc_lock, "xDMA proc", NULL, MTX_DEF);

        TAILQ_INIT(&xchan->bank);
        TAILQ_INIT(&xchan->queue_in);
        TAILQ_INIT(&xchan->queue_out);
        TAILQ_INIT(&xchan->processing);

        if (xchan->caps & XCHAN_CAP_IOMMU)
                xdma_iommu_init(&xchan->xio);

        TAILQ_INSERT_TAIL(&xdma->channels, xchan, xchan_next);

        XDMA_UNLOCK();

        return (xchan);
}

int
xdma_channel_free(xdma_channel_t *xchan)
{
        xdma_controller_t *xdma;
        int err;

        xdma = xchan->xdma;
        KASSERT(xdma != NULL, ("xdma is NULL"));

        XDMA_LOCK();

        /* Free the real DMA channel. */
        err = XDMA_CHANNEL_FREE(xdma->dma_dev, xchan);
        if (err != 0) {
                device_printf(xdma->dev,
                    "%s: Can't free real hw channel.\n", __func__);
                XDMA_UNLOCK();
                return (-1);
        }

        if (xchan->flags & XCHAN_TYPE_SG)
                xdma_channel_free_sg(xchan);

        if (xchan->caps & XCHAN_CAP_IOMMU)
                xdma_iommu_release(&xchan->xio);

        xdma_teardown_all_intr(xchan);

        mtx_destroy(&xchan->mtx_lock);
        mtx_destroy(&xchan->mtx_qin_lock);
        mtx_destroy(&xchan->mtx_qout_lock);
        mtx_destroy(&xchan->mtx_bank_lock);
        mtx_destroy(&xchan->mtx_proc_lock);

        TAILQ_REMOVE(&xdma->channels, xchan, xchan_next);

        free(xchan, M_XDMA);

        XDMA_UNLOCK();

        return (0);
}

int
xdma_setup_intr(xdma_channel_t *xchan, int flags,
    int (*cb)(void *, xdma_transfer_status_t *),
    void *arg, void **ihandler)
{
        struct xdma_intr_handler *ih;
        xdma_controller_t *xdma;

        xdma = xchan->xdma;
        KASSERT(xdma != NULL, ("xdma is NULL"));

        /* Sanity check. */
        if (cb == NULL) {
                device_printf(xdma->dev,
                    "%s: Can't setup interrupt handler.\n",
                    __func__);

                return (-1);
        }

        ih = malloc(sizeof(struct xdma_intr_handler),
            M_XDMA, M_WAITOK | M_ZERO);
        ih->flags = flags;
        ih->cb = cb;
        ih->cb_user = arg;

        XCHAN_LOCK(xchan);
        TAILQ_INSERT_TAIL(&xchan->ie_handlers, ih, ih_next);
        XCHAN_UNLOCK(xchan);

        if (ihandler != NULL)
                *ihandler = ih;

        return (0);
}

int
xdma_teardown_intr(xdma_channel_t *xchan, struct xdma_intr_handler *ih)
{
        xdma_controller_t *xdma;

        xdma = xchan->xdma;
        KASSERT(xdma != NULL, ("xdma is NULL"));

        /* Sanity check. */
        if (ih == NULL) {
                device_printf(xdma->dev,
                    "%s: Can't teardown interrupt.\n", __func__);
                return (-1);
        }

        TAILQ_REMOVE(&xchan->ie_handlers, ih, ih_next);
        free(ih, M_XDMA);

        return (0);
}

int
xdma_teardown_all_intr(xdma_channel_t *xchan)
{
        struct xdma_intr_handler *ih_tmp;
        struct xdma_intr_handler *ih;

        KASSERT(xchan->xdma != NULL, ("xdma is NULL"));

        TAILQ_FOREACH_SAFE(ih, &xchan->ie_handlers, ih_next, ih_tmp) {
                TAILQ_REMOVE(&xchan->ie_handlers, ih, ih_next);
                free(ih, M_XDMA);
        }

        return (0);
}

int
xdma_request(xdma_channel_t *xchan, struct xdma_request *req)
{
        xdma_controller_t *xdma;
        int ret;

        xdma = xchan->xdma;

        KASSERT(xdma != NULL, ("xdma is NULL"));

        XCHAN_LOCK(xchan);
        ret = XDMA_CHANNEL_REQUEST(xdma->dma_dev, xchan, req);
        if (ret != 0) {
                device_printf(xdma->dev,
                    "%s: Can't request a transfer.\n", __func__);
                XCHAN_UNLOCK(xchan);

                return (-1);
        }
        XCHAN_UNLOCK(xchan);

        return (0);
}

int
xdma_control(xdma_channel_t *xchan, enum xdma_command cmd)
{
        xdma_controller_t *xdma;
        int ret;

        xdma = xchan->xdma;
        KASSERT(xdma != NULL, ("xdma is NULL"));

        ret = XDMA_CHANNEL_CONTROL(xdma->dma_dev, xchan, cmd);
        if (ret != 0) {
                device_printf(xdma->dev,
                    "%s: Can't process command.\n", __func__);
                return (-1);
        }

        return (0);
}

void
xdma_callback(xdma_channel_t *xchan, xdma_transfer_status_t *status)
{
        struct xdma_intr_handler *ih_tmp;
        struct xdma_intr_handler *ih;
        struct epoch_tracker et;

        KASSERT(xchan->xdma != NULL, ("xdma is NULL"));

        TAILQ_FOREACH_SAFE(ih, &xchan->ie_handlers, ih_next, ih_tmp) {
                if (ih->cb != NULL) {
                        if (ih->flags & XDMA_INTR_NET)
                                NET_EPOCH_ENTER(et);
                        ih->cb(ih->cb_user, status);
                        if (ih->flags & XDMA_INTR_NET)
                                NET_EPOCH_EXIT(et);
                }
        }

        if (xchan->flags & XCHAN_TYPE_SG)
                xdma_queue_submit(xchan);
}

#ifdef FDT
/*
 * Notify the DMA driver we have machine-dependent data in FDT.
 */
static int
xdma_ofw_md_data(xdma_controller_t *xdma, pcell_t *cells, int ncells)
{
        uint32_t ret;

        ret = XDMA_OFW_MD_DATA(xdma->dma_dev,
            cells, ncells, (void **)&xdma->data);

        return (ret);
}

int
xdma_handle_mem_node(vmem_t *vmem, phandle_t memory)
{
        pcell_t reg[FDT_REG_CELLS * FDT_MEM_REGIONS];
        pcell_t *regp;
        int addr_cells, size_cells;
        int i, reg_len, ret, tuple_size, tuples;
        u_long mem_start, mem_size;

        if ((ret = fdt_addrsize_cells(OF_parent(memory), &addr_cells,
            &size_cells)) != 0)
                return (ret);

        if (addr_cells > 2)
                return (ERANGE);

        tuple_size = sizeof(pcell_t) * (addr_cells + size_cells);
        reg_len = OF_getproplen(memory, "reg");
        if (reg_len <= 0 || reg_len > sizeof(reg))
                return (ERANGE);

        if (OF_getprop(memory, "reg", reg, reg_len) <= 0)
                return (ENXIO);

        tuples = reg_len / tuple_size;
        regp = (pcell_t *)&reg;
        for (i = 0; i < tuples; i++) {
                ret = fdt_data_to_res(regp, addr_cells, size_cells,
                    &mem_start, &mem_size);
                if (ret != 0)
                        return (ret);

                vmem_add(vmem, mem_start, mem_size, 0);
                regp += addr_cells + size_cells;
        }

        return (0);
}

vmem_t *
xdma_get_memory(device_t dev)
{
        phandle_t mem_node, node;
        pcell_t mem_handle;
        vmem_t *vmem;

        node = ofw_bus_get_node(dev);
        if (node <= 0) {
                device_printf(dev,
                    "%s called on not ofw based device.\n", __func__);
                return (NULL);
        }

        if (!OF_hasprop(node, "memory-region"))
                return (NULL);

        if (OF_getencprop(node, "memory-region", (void *)&mem_handle,
            sizeof(mem_handle)) <= 0)
                return (NULL);

        vmem = vmem_create("xDMA vmem", 0, 0, PAGE_SIZE,
            PAGE_SIZE, M_BESTFIT | M_WAITOK);
        if (vmem == NULL)
                return (NULL);

        mem_node = OF_node_from_xref(mem_handle);
        if (xdma_handle_mem_node(vmem, mem_node) != 0) {
                vmem_destroy(vmem);
                return (NULL);
        }

        return (vmem);
}

void
xdma_put_memory(vmem_t *vmem)
{

        vmem_destroy(vmem);
}

void
xchan_set_memory(xdma_channel_t *xchan, vmem_t *vmem)
{

        xchan->vmem = vmem;
}

/*
 * Allocate xdma controller.
 */
xdma_controller_t *
xdma_ofw_get(device_t dev, const char *prop)
{
        phandle_t node, parent;
        xdma_controller_t *xdma;
        device_t dma_dev;
        pcell_t *cells;
        int ncells;
        int error;
        int ndmas;
        int idx;

        node = ofw_bus_get_node(dev);
        if (node <= 0)
                device_printf(dev,
                    "%s called on not ofw based device.\n", __func__);

        error = ofw_bus_parse_xref_list_get_length(node,
            "dmas", "#dma-cells", &ndmas);
        if (error) {
                device_printf(dev,
                    "%s can't get dmas list.\n", __func__);
                return (NULL);
        }

        if (ndmas == 0) {
                device_printf(dev,
                    "%s dmas list is empty.\n", __func__);
                return (NULL);
        }

        error = ofw_bus_find_string_index(node, "dma-names", prop, &idx);
        if (error != 0) {
                device_printf(dev,
                    "%s can't find string index.\n", __func__);
                return (NULL);
        }

        error = ofw_bus_parse_xref_list_alloc(node, "dmas", "#dma-cells",
            idx, &parent, &ncells, &cells);
        if (error != 0) {
                device_printf(dev,
                    "%s can't get dma device xref.\n", __func__);
                return (NULL);
        }

        dma_dev = OF_device_from_xref(parent);
        if (dma_dev == NULL) {
                device_printf(dev,
                    "%s can't get dma device.\n", __func__);
                return (NULL);
        }

        xdma = malloc(sizeof(struct xdma_controller),
            M_XDMA, M_WAITOK | M_ZERO);
        xdma->dev = dev;
        xdma->dma_dev = dma_dev;

        TAILQ_INIT(&xdma->channels);

        xdma_ofw_md_data(xdma, cells, ncells);
        free(cells, M_OFWPROP);

        return (xdma);
}
#endif

/*
 * Allocate xdma controller.
 */
xdma_controller_t *
xdma_get(device_t dev, device_t dma_dev)
{
        xdma_controller_t *xdma;

        xdma = malloc(sizeof(struct xdma_controller),
            M_XDMA, M_WAITOK | M_ZERO);
        xdma->dev = dev;
        xdma->dma_dev = dma_dev;

        TAILQ_INIT(&xdma->channels);

        return (xdma);
}

/*
 * Free xDMA controller object.
 */
int
xdma_put(xdma_controller_t *xdma)
{

        XDMA_LOCK();

        /* Ensure no channels allocated. */
        if (!TAILQ_EMPTY(&xdma->channels)) {
                device_printf(xdma->dev, "%s: Can't free xDMA\n", __func__);
                return (-1);
        }

        free(xdma->data, M_DEVBUF);
        free(xdma, M_XDMA);

        XDMA_UNLOCK();

        return (0);
}

static void
xdma_init(void *dummy __unused)
{

        mtx_init(&xdma_mtx, "xDMA", NULL, MTX_DEF);
}

SYSINIT(xdma, SI_SUB_DRIVERS, SI_ORDER_FIRST, xdma_init, NULL);