// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
/*
 * Copyright 2013-2016 Freescale Semiconductor Inc.
 * Copyright 2016-2017,2019-2020 NXP
 */

#include <linux/device.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/vfio.h>
#include <linux/fsl/mc.h>
#include <linux/delay.h>
#include <linux/io-64-nonatomic-hi-lo.h>

#include "vfio_fsl_mc_private.h"

static struct fsl_mc_driver vfio_fsl_mc_driver;

static int vfio_fsl_mc_open_device(struct vfio_device *core_vdev)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        int count = mc_dev->obj_desc.region_count;
        int i;

        vdev->regions = kzalloc_objs(struct vfio_fsl_mc_region, count,
                                     GFP_KERNEL_ACCOUNT);
        if (!vdev->regions)
                return -ENOMEM;

        for (i = 0; i < count; i++) {
                struct resource *res = &mc_dev->regions[i];
                int no_mmap = is_fsl_mc_bus_dprc(mc_dev);

                vdev->regions[i].addr = res->start;
                vdev->regions[i].size = resource_size(res);
                vdev->regions[i].type = mc_dev->regions[i].flags & IORESOURCE_BITS;
                /*
                 * Only regions addressed with PAGE granularity may be
                 * MMAPed securely.
                 */
                if (!no_mmap && !(vdev->regions[i].addr & ~PAGE_MASK) &&
                                !(vdev->regions[i].size & ~PAGE_MASK))
                        vdev->regions[i].flags |=
                                        VFIO_REGION_INFO_FLAG_MMAP;
                vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_READ;
                if (!(mc_dev->regions[i].flags & IORESOURCE_READONLY))
                        vdev->regions[i].flags |= VFIO_REGION_INFO_FLAG_WRITE;
        }

        return 0;
}

static void vfio_fsl_mc_regions_cleanup(struct vfio_fsl_mc_device *vdev)
{
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        int i;

        for (i = 0; i < mc_dev->obj_desc.region_count; i++)
                iounmap(vdev->regions[i].ioaddr);
        kfree(vdev->regions);
}

static int vfio_fsl_mc_reset_device(struct vfio_fsl_mc_device *vdev)
{
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        int ret = 0;

        if (is_fsl_mc_bus_dprc(vdev->mc_dev)) {
                return dprc_reset_container(mc_dev->mc_io, 0,
                                        mc_dev->mc_handle,
                                        mc_dev->obj_desc.id,
                                        DPRC_RESET_OPTION_NON_RECURSIVE);
        } else {
                u16 token;

                ret = fsl_mc_obj_open(mc_dev->mc_io, 0, mc_dev->obj_desc.id,
                                      mc_dev->obj_desc.type,
                                      &token);
                if (ret)
                        goto out;
                ret = fsl_mc_obj_reset(mc_dev->mc_io, 0, token);
                if (ret) {
                        fsl_mc_obj_close(mc_dev->mc_io, 0, token);
                        goto out;
                }
                ret = fsl_mc_obj_close(mc_dev->mc_io, 0, token);
        }
out:
        return ret;
}

static void vfio_fsl_mc_close_device(struct vfio_device *core_vdev)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        struct device *cont_dev = fsl_mc_cont_dev(&mc_dev->dev);
        struct fsl_mc_device *mc_cont = to_fsl_mc_device(cont_dev);
        int ret;

        vfio_fsl_mc_regions_cleanup(vdev);

        /* reset the device before cleaning up the interrupts */
        ret = vfio_fsl_mc_reset_device(vdev);

        if (ret)
                dev_warn(&mc_cont->dev,
                         "VFIO_FSL_MC: reset device has failed (%d)\n", ret);

        vfio_fsl_mc_irqs_cleanup(vdev);

        fsl_mc_cleanup_irq_pool(mc_cont);
}

static int vfio_fsl_mc_ioctl_get_region_info(struct vfio_device *core_vdev,
                                             struct vfio_region_info *info,
                                             struct vfio_info_cap *caps)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        struct fsl_mc_device *mc_dev = vdev->mc_dev;

        if (info->index >= mc_dev->obj_desc.region_count)
                return -EINVAL;

        /* map offset to the physical address  */
        info->offset = VFIO_FSL_MC_INDEX_TO_OFFSET(info->index);
        info->size = vdev->regions[info->index].size;
        info->flags = vdev->regions[info->index].flags;
        return 0;
}

static long vfio_fsl_mc_ioctl(struct vfio_device *core_vdev,
                              unsigned int cmd, unsigned long arg)
{
        unsigned long minsz;
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        struct fsl_mc_device *mc_dev = vdev->mc_dev;

        switch (cmd) {
        case VFIO_DEVICE_GET_INFO:
        {
                struct vfio_device_info info;

                minsz = offsetofend(struct vfio_device_info, num_irqs);

                if (copy_from_user(&info, (void __user *)arg, minsz))
                        return -EFAULT;

                if (info.argsz < minsz)
                        return -EINVAL;

                info.flags = VFIO_DEVICE_FLAGS_FSL_MC;

                if (is_fsl_mc_bus_dprc(mc_dev))
                        info.flags |= VFIO_DEVICE_FLAGS_RESET;

                info.num_regions = mc_dev->obj_desc.region_count;
                info.num_irqs = mc_dev->obj_desc.irq_count;

                return copy_to_user((void __user *)arg, &info, minsz) ?
                        -EFAULT : 0;
        }
        case VFIO_DEVICE_GET_IRQ_INFO:
        {
                struct vfio_irq_info info;

                minsz = offsetofend(struct vfio_irq_info, count);
                if (copy_from_user(&info, (void __user *)arg, minsz))
                        return -EFAULT;

                if (info.argsz < minsz)
                        return -EINVAL;

                if (info.index >= mc_dev->obj_desc.irq_count)
                        return -EINVAL;

                info.flags = VFIO_IRQ_INFO_EVENTFD;
                info.count = 1;

                if (copy_to_user((void __user *)arg, &info, minsz))
                        return -EFAULT;
                return 0;
        }
        case VFIO_DEVICE_SET_IRQS:
        {
                struct vfio_irq_set hdr;
                u8 *data = NULL;
                int ret = 0;
                size_t data_size = 0;

                minsz = offsetofend(struct vfio_irq_set, count);

                if (copy_from_user(&hdr, (void __user *)arg, minsz))
                        return -EFAULT;

                ret = vfio_set_irqs_validate_and_prepare(&hdr, mc_dev->obj_desc.irq_count,
                                        mc_dev->obj_desc.irq_count, &data_size);
                if (ret)
                        return ret;

                if (data_size) {
                        data = memdup_user((void __user *)(arg + minsz),
                                   data_size);
                        if (IS_ERR(data))
                                return PTR_ERR(data);
                }

                mutex_lock(&vdev->igate);
                ret = vfio_fsl_mc_set_irqs_ioctl(vdev, hdr.flags,
                                                 hdr.index, hdr.start,
                                                 hdr.count, data);
                mutex_unlock(&vdev->igate);
                kfree(data);

                return ret;
        }
        case VFIO_DEVICE_RESET:
        {
                return vfio_fsl_mc_reset_device(vdev);

        }
        default:
                return -ENOTTY;
        }
}

static ssize_t vfio_fsl_mc_read(struct vfio_device *core_vdev, char __user *buf,
                                size_t count, loff_t *ppos)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        unsigned int index = VFIO_FSL_MC_OFFSET_TO_INDEX(*ppos);
        loff_t off = *ppos & VFIO_FSL_MC_OFFSET_MASK;
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        struct vfio_fsl_mc_region *region;
        u64 data[8];
        int i;

        if (index >= mc_dev->obj_desc.region_count)
                return -EINVAL;

        region = &vdev->regions[index];

        if (!(region->flags & VFIO_REGION_INFO_FLAG_READ))
                return -EINVAL;

        if (!region->ioaddr) {
                region->ioaddr = ioremap(region->addr, region->size);
                if (!region->ioaddr)
                        return -ENOMEM;
        }

        if (count != 64 || off != 0)
                return -EINVAL;

        for (i = 7; i >= 0; i--)
                data[i] = readq(region->ioaddr + i * sizeof(uint64_t));

        if (copy_to_user(buf, data, 64))
                return -EFAULT;

        return count;
}

#define MC_CMD_COMPLETION_TIMEOUT_MS    5000
#define MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS    500

static int vfio_fsl_mc_send_command(void __iomem *ioaddr, uint64_t *cmd_data)
{
        int i;
        enum mc_cmd_status status;
        unsigned long timeout_usecs = MC_CMD_COMPLETION_TIMEOUT_MS * 1000;

        /* Write at command parameter into portal */
        for (i = 7; i >= 1; i--)
                writeq_relaxed(cmd_data[i], ioaddr + i * sizeof(uint64_t));

        /* Write command header in the end */
        writeq(cmd_data[0], ioaddr);

        /* Wait for response before returning to user-space
         * This can be optimized in future to even prepare response
         * before returning to user-space and avoid read ioctl.
         */
        for (;;) {
                u64 header;
                struct mc_cmd_header *resp_hdr;

                header = cpu_to_le64(readq_relaxed(ioaddr));

                resp_hdr = (struct mc_cmd_header *)&header;
                status = (enum mc_cmd_status)resp_hdr->status;
                if (status != MC_CMD_STATUS_READY)
                        break;

                udelay(MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS);
                timeout_usecs -= MC_CMD_COMPLETION_POLLING_MAX_SLEEP_USECS;
                if (timeout_usecs == 0)
                        return -ETIMEDOUT;
        }

        return 0;
}

static ssize_t vfio_fsl_mc_write(struct vfio_device *core_vdev,
                                 const char __user *buf, size_t count,
                                 loff_t *ppos)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        unsigned int index = VFIO_FSL_MC_OFFSET_TO_INDEX(*ppos);
        loff_t off = *ppos & VFIO_FSL_MC_OFFSET_MASK;
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        struct vfio_fsl_mc_region *region;
        u64 data[8];
        int ret;

        if (index >= mc_dev->obj_desc.region_count)
                return -EINVAL;

        region = &vdev->regions[index];

        if (!(region->flags & VFIO_REGION_INFO_FLAG_WRITE))
                return -EINVAL;

        if (!region->ioaddr) {
                region->ioaddr = ioremap(region->addr, region->size);
                if (!region->ioaddr)
                        return -ENOMEM;
        }

        if (count != 64 || off != 0)
                return -EINVAL;

        if (copy_from_user(&data, buf, 64))
                return -EFAULT;

        ret = vfio_fsl_mc_send_command(region->ioaddr, data);
        if (ret)
                return ret;

        return count;

}

static int vfio_fsl_mc_mmap_mmio(struct vfio_fsl_mc_region region,
                                 struct vm_area_struct *vma)
{
        u64 size = vma->vm_end - vma->vm_start;
        u64 pgoff, base;
        u8 region_cacheable;

        pgoff = vma->vm_pgoff &
                ((1U << (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
        base = pgoff << PAGE_SHIFT;

        if (region.size < PAGE_SIZE || base + size > region.size)
                return -EINVAL;

        region_cacheable = (region.type & FSL_MC_REGION_CACHEABLE) &&
                           (region.type & FSL_MC_REGION_SHAREABLE);
        if (!region_cacheable)
                vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);

        vma->vm_pgoff = (region.addr >> PAGE_SHIFT) + pgoff;

        return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                               size, vma->vm_page_prot);
}

static int vfio_fsl_mc_mmap(struct vfio_device *core_vdev,
                            struct vm_area_struct *vma)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        unsigned int index;

        index = vma->vm_pgoff >> (VFIO_FSL_MC_OFFSET_SHIFT - PAGE_SHIFT);

        if (vma->vm_end < vma->vm_start)
                return -EINVAL;
        if (vma->vm_start & ~PAGE_MASK)
                return -EINVAL;
        if (vma->vm_end & ~PAGE_MASK)
                return -EINVAL;
        if (!(vma->vm_flags & VM_SHARED))
                return -EINVAL;
        if (index >= mc_dev->obj_desc.region_count)
                return -EINVAL;

        if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_MMAP))
                return -EINVAL;

        if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_READ)
                        && (vma->vm_flags & VM_READ))
                return -EINVAL;

        if (!(vdev->regions[index].flags & VFIO_REGION_INFO_FLAG_WRITE)
                        && (vma->vm_flags & VM_WRITE))
                return -EINVAL;

        vma->vm_private_data = mc_dev;

        return vfio_fsl_mc_mmap_mmio(vdev->regions[index], vma);
}

static const struct vfio_device_ops vfio_fsl_mc_ops;
static int vfio_fsl_mc_bus_notifier(struct notifier_block *nb,
                                    unsigned long action, void *data)
{
        struct vfio_fsl_mc_device *vdev = container_of(nb,
                                        struct vfio_fsl_mc_device, nb);
        struct device *dev = data;
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(dev);
        struct fsl_mc_device *mc_cont = to_fsl_mc_device(mc_dev->dev.parent);

        if (action == BUS_NOTIFY_ADD_DEVICE &&
            vdev->mc_dev == mc_cont) {
                mc_dev->driver_override = kasprintf(GFP_KERNEL, "%s",
                                                    vfio_fsl_mc_ops.name);
                if (!mc_dev->driver_override)
                        dev_warn(dev, "VFIO_FSL_MC: Setting driver override for device in dprc %s failed\n",
                                 dev_name(&mc_cont->dev));
                else
                        dev_info(dev, "VFIO_FSL_MC: Setting driver override for device in dprc %s\n",
                                 dev_name(&mc_cont->dev));
        } else if (action == BUS_NOTIFY_BOUND_DRIVER &&
                vdev->mc_dev == mc_cont) {
                struct fsl_mc_driver *mc_drv = to_fsl_mc_driver(dev->driver);

                if (mc_drv && mc_drv != &vfio_fsl_mc_driver)
                        dev_warn(dev, "VFIO_FSL_MC: Object %s bound to driver %s while DPRC bound to vfio-fsl-mc\n",
                                 dev_name(dev), mc_drv->driver.name);
        }

        return 0;
}

static int vfio_fsl_mc_init_device(struct vfio_fsl_mc_device *vdev)
{
        struct fsl_mc_device *mc_dev = vdev->mc_dev;
        int ret;

        /* Non-dprc devices share mc_io from parent */
        if (!is_fsl_mc_bus_dprc(mc_dev)) {
                struct fsl_mc_device *mc_cont = to_fsl_mc_device(mc_dev->dev.parent);

                mc_dev->mc_io = mc_cont->mc_io;
                return 0;
        }

        vdev->nb.notifier_call = vfio_fsl_mc_bus_notifier;
        ret = bus_register_notifier(&fsl_mc_bus_type, &vdev->nb);
        if (ret)
                return ret;

        /* open DPRC, allocate a MC portal */
        ret = dprc_setup(mc_dev);
        if (ret) {
                dev_err(&mc_dev->dev, "VFIO_FSL_MC: Failed to setup DPRC (%d)\n", ret);
                goto out_nc_unreg;
        }
        return 0;

out_nc_unreg:
        bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
        return ret;
}

static int vfio_fsl_mc_scan_container(struct fsl_mc_device *mc_dev)
{
        int ret;

        /* non dprc devices do not scan for other devices */
        if (!is_fsl_mc_bus_dprc(mc_dev))
                return 0;
        ret = dprc_scan_container(mc_dev, false);
        if (ret) {
                dev_err(&mc_dev->dev,
                        "VFIO_FSL_MC: Container scanning failed (%d)\n", ret);
                dprc_remove_devices(mc_dev, NULL, 0);
                return ret;
        }
        return 0;
}

static void vfio_fsl_uninit_device(struct vfio_fsl_mc_device *vdev)
{
        struct fsl_mc_device *mc_dev = vdev->mc_dev;

        if (!is_fsl_mc_bus_dprc(mc_dev))
                return;

        dprc_cleanup(mc_dev);
        bus_unregister_notifier(&fsl_mc_bus_type, &vdev->nb);
}

static int vfio_fsl_mc_init_dev(struct vfio_device *core_vdev)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);
        struct fsl_mc_device *mc_dev = to_fsl_mc_device(core_vdev->dev);
        int ret;

        vdev->mc_dev = mc_dev;
        mutex_init(&vdev->igate);

        if (is_fsl_mc_bus_dprc(mc_dev))
                ret = vfio_assign_device_set(core_vdev, &mc_dev->dev);
        else
                ret = vfio_assign_device_set(core_vdev, mc_dev->dev.parent);

        if (ret)
                return ret;

        /* device_set is released by vfio core if @init fails */
        return vfio_fsl_mc_init_device(vdev);
}

static int vfio_fsl_mc_probe(struct fsl_mc_device *mc_dev)
{
        struct vfio_fsl_mc_device *vdev;
        struct device *dev = &mc_dev->dev;
        int ret;

        vdev = vfio_alloc_device(vfio_fsl_mc_device, vdev, dev,
                                 &vfio_fsl_mc_ops);
        if (IS_ERR(vdev))
                return PTR_ERR(vdev);

        ret = vfio_register_group_dev(&vdev->vdev);
        if (ret) {
                dev_err(dev, "VFIO_FSL_MC: Failed to add to vfio group\n");
                goto out_put_vdev;
        }

        ret = vfio_fsl_mc_scan_container(mc_dev);
        if (ret)
                goto out_group_dev;
        dev_set_drvdata(dev, vdev);
        return 0;

out_group_dev:
        vfio_unregister_group_dev(&vdev->vdev);
out_put_vdev:
        vfio_put_device(&vdev->vdev);
        return ret;
}

static void vfio_fsl_mc_release_dev(struct vfio_device *core_vdev)
{
        struct vfio_fsl_mc_device *vdev =
                container_of(core_vdev, struct vfio_fsl_mc_device, vdev);

        vfio_fsl_uninit_device(vdev);
        mutex_destroy(&vdev->igate);
}

static void vfio_fsl_mc_remove(struct fsl_mc_device *mc_dev)
{
        struct device *dev = &mc_dev->dev;
        struct vfio_fsl_mc_device *vdev = dev_get_drvdata(dev);

        vfio_unregister_group_dev(&vdev->vdev);
        dprc_remove_devices(mc_dev, NULL, 0);
        vfio_put_device(&vdev->vdev);
}

static const struct vfio_device_ops vfio_fsl_mc_ops = {
        .name           = "vfio-fsl-mc",
        .init           = vfio_fsl_mc_init_dev,
        .release        = vfio_fsl_mc_release_dev,
        .open_device    = vfio_fsl_mc_open_device,
        .close_device   = vfio_fsl_mc_close_device,
        .ioctl          = vfio_fsl_mc_ioctl,
        .get_region_info_caps = vfio_fsl_mc_ioctl_get_region_info,
        .read           = vfio_fsl_mc_read,
        .write          = vfio_fsl_mc_write,
        .mmap           = vfio_fsl_mc_mmap,
        .bind_iommufd   = vfio_iommufd_physical_bind,
        .unbind_iommufd = vfio_iommufd_physical_unbind,
        .attach_ioas    = vfio_iommufd_physical_attach_ioas,
        .detach_ioas    = vfio_iommufd_physical_detach_ioas,
};

static struct fsl_mc_driver vfio_fsl_mc_driver = {
        .probe          = vfio_fsl_mc_probe,
        .remove         = vfio_fsl_mc_remove,
        .driver = {
                .name   = "vfio-fsl-mc",
        },
        .driver_managed_dma = true,
};

module_fsl_mc_driver(vfio_fsl_mc_driver);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("VFIO for FSL-MC devices - User Level meta-driver");