// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for FPGA Accelerated Function Unit (AFU) MMIO Region Management
 *
 * Copyright (C) 2017-2018 Intel Corporation, Inc.
 *
 * Authors:
 *   Wu Hao <hao.wu@intel.com>
 *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
 */
#include "dfl-afu.h"

/**
 * afu_mmio_region_init - init function for afu mmio region support
 * @fdata: afu feature dev data
 */
void afu_mmio_region_init(struct dfl_feature_dev_data *fdata)
{
        struct dfl_afu *afu = dfl_fpga_fdata_get_private(fdata);

        INIT_LIST_HEAD(&afu->regions);
}

#define for_each_region(region, afu)    \
        list_for_each_entry((region), &(afu)->regions, node)

static struct dfl_afu_mmio_region *get_region_by_index(struct dfl_afu *afu,
                                                       u32 region_index)
{
        struct dfl_afu_mmio_region *region;

        for_each_region(region, afu)
                if (region->index == region_index)
                        return region;

        return NULL;
}

/**
 * afu_mmio_region_add - add a mmio region to given feature dev.
 *
 * @fdata: afu feature dev data
 * @region_index: region index.
 * @region_size: region size.
 * @phys: region's physical address of this region.
 * @flags: region flags (access permission).
 *
 * Return: 0 on success, negative error code otherwise.
 */
int afu_mmio_region_add(struct dfl_feature_dev_data *fdata,
                        u32 region_index, u64 region_size, u64 phys, u32 flags)
{
        struct device *dev = &fdata->dev->dev;
        struct dfl_afu_mmio_region *region;
        struct dfl_afu *afu;
        int ret = 0;

        region = devm_kzalloc(dev, sizeof(*region), GFP_KERNEL);
        if (!region)
                return -ENOMEM;

        region->index = region_index;
        region->size = region_size;
        region->phys = phys;
        region->flags = flags;

        mutex_lock(&fdata->lock);

        afu = dfl_fpga_fdata_get_private(fdata);

        /* check if @index already exists */
        if (get_region_by_index(afu, region_index)) {
                mutex_unlock(&fdata->lock);
                ret = -EEXIST;
                goto exit;
        }

        region_size = PAGE_ALIGN(region_size);
        region->offset = afu->region_cur_offset;
        list_add(&region->node, &afu->regions);

        afu->region_cur_offset += region_size;
        afu->num_regions++;
        mutex_unlock(&fdata->lock);

        return 0;

exit:
        devm_kfree(dev, region);
        return ret;
}

/**
 * afu_mmio_region_destroy - destroy all mmio regions under given feature dev.
 * @fdata: afu feature dev data
 */
void afu_mmio_region_destroy(struct dfl_feature_dev_data *fdata)
{
        struct dfl_afu *afu = dfl_fpga_fdata_get_private(fdata);
        struct dfl_afu_mmio_region *tmp, *region;

        list_for_each_entry_safe(region, tmp, &afu->regions, node)
                devm_kfree(&fdata->dev->dev, region);
}

/**
 * afu_mmio_region_get_by_index - find an afu region by index.
 * @fdata: afu feature dev data
 * @region_index: region index.
 * @pregion: ptr to region for result.
 *
 * Return: 0 on success, negative error code otherwise.
 */
int afu_mmio_region_get_by_index(struct dfl_feature_dev_data *fdata,
                                 u32 region_index,
                                 struct dfl_afu_mmio_region *pregion)
{
        struct dfl_afu_mmio_region *region;
        struct dfl_afu *afu;
        int ret = 0;

        mutex_lock(&fdata->lock);
        afu = dfl_fpga_fdata_get_private(fdata);
        region = get_region_by_index(afu, region_index);
        if (!region) {
                ret = -EINVAL;
                goto exit;
        }
        *pregion = *region;
exit:
        mutex_unlock(&fdata->lock);
        return ret;
}

/**
 * afu_mmio_region_get_by_offset - find an afu mmio region by offset and size
 *
 * @fdata: afu feature dev data
 * @offset: region offset from start of the device fd.
 * @size: region size.
 * @pregion: ptr to region for result.
 *
 * Find the region which fully contains the region described by input
 * parameters (offset and size) from the feature dev's region linked list.
 *
 * Return: 0 on success, negative error code otherwise.
 */
int afu_mmio_region_get_by_offset(struct dfl_feature_dev_data *fdata,
                                  u64 offset, u64 size,
                                  struct dfl_afu_mmio_region *pregion)
{
        struct dfl_afu_mmio_region *region;
        struct dfl_afu *afu;
        int ret = 0;

        mutex_lock(&fdata->lock);
        afu = dfl_fpga_fdata_get_private(fdata);
        for_each_region(region, afu)
                if (region->offset <= offset &&
                    region->offset + region->size >= offset + size) {
                        *pregion = *region;
                        goto exit;
                }
        ret = -EINVAL;
exit:
        mutex_unlock(&fdata->lock);
        return ret;
}