linux/drivers/fpga/dfl-afu-dma-region.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for FPGA Accelerated Function Unit (AFU) DMA Region Management
 *
 * Copyright (C) 2017-2018 Intel Corporation, Inc.
 *
 * Authors:
 *   Wu Hao <[email protected]>
 *   Xiao Guangrong <[email protected]>
 */

#include <linux/dma-mapping.h>
#include <linux/sched/signal.h>
#include <linux/uaccess.h>
#include <linux/mm.h>

#include "dfl-afu.h"

void afu_dma_region_init(struct dfl_feature_platform_data *pdata)
{ … }

/**
 * afu_dma_pin_pages - pin pages of given dma memory region
 * @pdata: feature device platform data
 * @region: dma memory region to be pinned
 *
 * Pin all the pages of given dfl_afu_dma_region.
 * Return 0 for success or negative error code.
 */
static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata,
			     struct dfl_afu_dma_region *region)
{ … }

/**
 * afu_dma_unpin_pages - unpin pages of given dma memory region
 * @pdata: feature device platform data
 * @region: dma memory region to be unpinned
 *
 * Unpin all the pages of given dfl_afu_dma_region.
 * Return 0 for success or negative error code.
 */
static void afu_dma_unpin_pages(struct dfl_feature_platform_data *pdata,
				struct dfl_afu_dma_region *region)
{ … }

/**
 * afu_dma_check_continuous_pages - check if pages are continuous
 * @region: dma memory region
 *
 * Return true if pages of given dma memory region have continuous physical
 * address, otherwise return false.
 */
static bool afu_dma_check_continuous_pages(struct dfl_afu_dma_region *region)
{ … }

/**
 * dma_region_check_iova - check if memory area is fully contained in the region
 * @region: dma memory region
 * @iova: address of the dma memory area
 * @size: size of the dma memory area
 *
 * Compare the dma memory area defined by @iova and @size with given dma region.
 * Return true if memory area is fully contained in the region, otherwise false.
 */
static bool dma_region_check_iova(struct dfl_afu_dma_region *region,
				  u64 iova, u64 size)
{ … }

/**
 * afu_dma_region_add - add given dma region to rbtree
 * @pdata: feature device platform data
 * @region: dma region to be added
 *
 * Return 0 for success, -EEXIST if dma region has already been added.
 *
 * Needs to be called with pdata->lock heold.
 */
static int afu_dma_region_add(struct dfl_feature_platform_data *pdata,
			      struct dfl_afu_dma_region *region)
{ … }

/**
 * afu_dma_region_remove - remove given dma region from rbtree
 * @pdata: feature device platform data
 * @region: dma region to be removed
 *
 * Needs to be called with pdata->lock heold.
 */
static void afu_dma_region_remove(struct dfl_feature_platform_data *pdata,
				  struct dfl_afu_dma_region *region)
{ … }

/**
 * afu_dma_region_destroy - destroy all regions in rbtree
 * @pdata: feature device platform data
 *
 * Needs to be called with pdata->lock heold.
 */
void afu_dma_region_destroy(struct dfl_feature_platform_data *pdata)
{ … }

/**
 * afu_dma_region_find - find the dma region from rbtree based on iova and size
 * @pdata: feature device platform data
 * @iova: address of the dma memory area
 * @size: size of the dma memory area
 *
 * It finds the dma region from the rbtree based on @iova and @size:
 * - if @size == 0, it finds the dma region which starts from @iova
 * - otherwise, it finds the dma region which fully contains
 *   [@iova, @iova+size)
 * If nothing is matched returns NULL.
 *
 * Needs to be called with pdata->lock held.
 */
struct dfl_afu_dma_region *
afu_dma_region_find(struct dfl_feature_platform_data *pdata, u64 iova, u64 size)
{ … }

/**
 * afu_dma_region_find_iova - find the dma region from rbtree by iova
 * @pdata: feature device platform data
 * @iova: address of the dma region
 *
 * Needs to be called with pdata->lock held.
 */
static struct dfl_afu_dma_region *
afu_dma_region_find_iova(struct dfl_feature_platform_data *pdata, u64 iova)
{ … }

/**
 * afu_dma_map_region - map memory region for dma
 * @pdata: feature device platform data
 * @user_addr: address of the memory region
 * @length: size of the memory region
 * @iova: pointer of iova address
 *
 * Map memory region defined by @user_addr and @length, and return dma address
 * of the memory region via @iova.
 * Return 0 for success, otherwise error code.
 */
int afu_dma_map_region(struct dfl_feature_platform_data *pdata,
		       u64 user_addr, u64 length, u64 *iova)
{ … }

/**
 * afu_dma_unmap_region - unmap dma memory region
 * @pdata: feature device platform data
 * @iova: dma address of the region
 *
 * Unmap dma memory region based on @iova.
 * Return 0 for success, otherwise error code.
 */
int afu_dma_unmap_region(struct dfl_feature_platform_data *pdata, u64 iova)
{ … }