1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for FPGA Accelerated Function Unit (AFU) MMIO Region Management
4  *
5  * Copyright (C) 2017-2018 Intel Corporation, Inc.
6  *
7  * Authors:
8  *   Wu Hao <hao.wu@intel.com>
9  *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
10  */
11 #include "dfl-afu.h"
12 
13 /**
14  * afu_mmio_region_init - init function for afu mmio region support
15  * @pdata: afu platform device's pdata.
16  */
afu_mmio_region_init(struct dfl_feature_platform_data * pdata)17 void afu_mmio_region_init(struct dfl_feature_platform_data *pdata)
18 {
19 	struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata);
20 
21 	INIT_LIST_HEAD(&afu->regions);
22 }
23 
24 #define for_each_region(region, afu)	\
25 	list_for_each_entry((region), &(afu)->regions, node)
26 
get_region_by_index(struct dfl_afu * afu,u32 region_index)27 static struct dfl_afu_mmio_region *get_region_by_index(struct dfl_afu *afu,
28 						       u32 region_index)
29 {
30 	struct dfl_afu_mmio_region *region;
31 
32 	for_each_region(region, afu)
33 		if (region->index == region_index)
34 			return region;
35 
36 	return NULL;
37 }
38 
39 /**
40  * afu_mmio_region_add - add a mmio region to given feature dev.
41  *
42  * @region_index: region index.
43  * @region_size: region size.
44  * @phys: region's physical address of this region.
45  * @flags: region flags (access permission).
46  *
47  * Return: 0 on success, negative error code otherwise.
48  */
afu_mmio_region_add(struct dfl_feature_platform_data * pdata,u32 region_index,u64 region_size,u64 phys,u32 flags)49 int afu_mmio_region_add(struct dfl_feature_platform_data *pdata,
50 			u32 region_index, u64 region_size, u64 phys, u32 flags)
51 {
52 	struct dfl_afu_mmio_region *region;
53 	struct dfl_afu *afu;
54 	int ret = 0;
55 
56 	region = devm_kzalloc(&pdata->dev->dev, sizeof(*region), GFP_KERNEL);
57 	if (!region)
58 		return -ENOMEM;
59 
60 	region->index = region_index;
61 	region->size = region_size;
62 	region->phys = phys;
63 	region->flags = flags;
64 
65 	mutex_lock(&pdata->lock);
66 
67 	afu = dfl_fpga_pdata_get_private(pdata);
68 
69 	/* check if @index already exists */
70 	if (get_region_by_index(afu, region_index)) {
71 		mutex_unlock(&pdata->lock);
72 		ret = -EEXIST;
73 		goto exit;
74 	}
75 
76 	region_size = PAGE_ALIGN(region_size);
77 	region->offset = afu->region_cur_offset;
78 	list_add(&region->node, &afu->regions);
79 
80 	afu->region_cur_offset += region_size;
81 	afu->num_regions++;
82 	mutex_unlock(&pdata->lock);
83 
84 	return 0;
85 
86 exit:
87 	devm_kfree(&pdata->dev->dev, region);
88 	return ret;
89 }
90 
91 /**
92  * afu_mmio_region_destroy - destroy all mmio regions under given feature dev.
93  * @pdata: afu platform device's pdata.
94  */
afu_mmio_region_destroy(struct dfl_feature_platform_data * pdata)95 void afu_mmio_region_destroy(struct dfl_feature_platform_data *pdata)
96 {
97 	struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata);
98 	struct dfl_afu_mmio_region *tmp, *region;
99 
100 	list_for_each_entry_safe(region, tmp, &afu->regions, node)
101 		devm_kfree(&pdata->dev->dev, region);
102 }
103 
104 /**
105  * afu_mmio_region_get_by_index - find an afu region by index.
106  * @pdata: afu platform device's pdata.
107  * @region_index: region index.
108  * @pregion: ptr to region for result.
109  *
110  * Return: 0 on success, negative error code otherwise.
111  */
afu_mmio_region_get_by_index(struct dfl_feature_platform_data * pdata,u32 region_index,struct dfl_afu_mmio_region * pregion)112 int afu_mmio_region_get_by_index(struct dfl_feature_platform_data *pdata,
113 				 u32 region_index,
114 				 struct dfl_afu_mmio_region *pregion)
115 {
116 	struct dfl_afu_mmio_region *region;
117 	struct dfl_afu *afu;
118 	int ret = 0;
119 
120 	mutex_lock(&pdata->lock);
121 	afu = dfl_fpga_pdata_get_private(pdata);
122 	region = get_region_by_index(afu, region_index);
123 	if (!region) {
124 		ret = -EINVAL;
125 		goto exit;
126 	}
127 	*pregion = *region;
128 exit:
129 	mutex_unlock(&pdata->lock);
130 	return ret;
131 }
132 
133 /**
134  * afu_mmio_region_get_by_offset - find an afu mmio region by offset and size
135  *
136  * @pdata: afu platform device's pdata.
137  * @offset: region offset from start of the device fd.
138  * @size: region size.
139  * @pregion: ptr to region for result.
140  *
141  * Find the region which fully contains the region described by input
142  * parameters (offset and size) from the feature dev's region linked list.
143  *
144  * Return: 0 on success, negative error code otherwise.
145  */
afu_mmio_region_get_by_offset(struct dfl_feature_platform_data * pdata,u64 offset,u64 size,struct dfl_afu_mmio_region * pregion)146 int afu_mmio_region_get_by_offset(struct dfl_feature_platform_data *pdata,
147 				  u64 offset, u64 size,
148 				  struct dfl_afu_mmio_region *pregion)
149 {
150 	struct dfl_afu_mmio_region *region;
151 	struct dfl_afu *afu;
152 	int ret = 0;
153 
154 	mutex_lock(&pdata->lock);
155 	afu = dfl_fpga_pdata_get_private(pdata);
156 	for_each_region(region, afu)
157 		if (region->offset <= offset &&
158 		    region->offset + region->size >= offset + size) {
159 			*pregion = *region;
160 			goto exit;
161 		}
162 	ret = -EINVAL;
163 exit:
164 	mutex_unlock(&pdata->lock);
165 	return ret;
166 }
167