xref: /linux/drivers/misc/ocxl/sysfs.c (revision d2912cb15bdda8ba4a5dd73396ad62641af2f520)
1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
3 #include <linux/sysfs.h>
4 #include "ocxl_internal.h"
5 
6 static inline struct ocxl_afu *to_afu(struct device *device)
7 {
8 	struct ocxl_file_info *info = container_of(device, struct ocxl_file_info, dev);
9 
10 	return info->afu;
11 }
12 
13 static ssize_t global_mmio_size_show(struct device *device,
14 				struct device_attribute *attr,
15 				char *buf)
16 {
17 	struct ocxl_afu *afu = to_afu(device);
18 
19 	return scnprintf(buf, PAGE_SIZE, "%d\n",
20 			afu->config.global_mmio_size);
21 }
22 
23 static ssize_t pp_mmio_size_show(struct device *device,
24 				struct device_attribute *attr,
25 				char *buf)
26 {
27 	struct ocxl_afu *afu = to_afu(device);
28 
29 	return scnprintf(buf, PAGE_SIZE, "%d\n",
30 			afu->config.pp_mmio_stride);
31 }
32 
33 static ssize_t afu_version_show(struct device *device,
34 				struct device_attribute *attr,
35 				char *buf)
36 {
37 	struct ocxl_afu *afu = to_afu(device);
38 
39 	return scnprintf(buf, PAGE_SIZE, "%hhu:%hhu\n",
40 			afu->config.version_major,
41 			afu->config.version_minor);
42 }
43 
44 static ssize_t contexts_show(struct device *device,
45 		struct device_attribute *attr,
46 		char *buf)
47 {
48 	struct ocxl_afu *afu = to_afu(device);
49 
50 	return scnprintf(buf, PAGE_SIZE, "%d/%d\n",
51 			afu->pasid_count, afu->pasid_max);
52 }
53 
54 static struct device_attribute afu_attrs[] = {
55 	__ATTR_RO(global_mmio_size),
56 	__ATTR_RO(pp_mmio_size),
57 	__ATTR_RO(afu_version),
58 	__ATTR_RO(contexts),
59 };
60 
61 static ssize_t global_mmio_read(struct file *filp, struct kobject *kobj,
62 				struct bin_attribute *bin_attr, char *buf,
63 				loff_t off, size_t count)
64 {
65 	struct ocxl_afu *afu = to_afu(kobj_to_dev(kobj));
66 
67 	if (count == 0 || off < 0 ||
68 		off >= afu->config.global_mmio_size)
69 		return 0;
70 	memcpy_fromio(buf, afu->global_mmio_ptr + off, count);
71 	return count;
72 }
73 
74 static vm_fault_t global_mmio_fault(struct vm_fault *vmf)
75 {
76 	struct vm_area_struct *vma = vmf->vma;
77 	struct ocxl_afu *afu = vma->vm_private_data;
78 	unsigned long offset;
79 
80 	if (vmf->pgoff >= (afu->config.global_mmio_size >> PAGE_SHIFT))
81 		return VM_FAULT_SIGBUS;
82 
83 	offset = vmf->pgoff;
84 	offset += (afu->global_mmio_start >> PAGE_SHIFT);
85 	return vmf_insert_pfn(vma, vmf->address, offset);
86 }
87 
88 static const struct vm_operations_struct global_mmio_vmops = {
89 	.fault = global_mmio_fault,
90 };
91 
92 static int global_mmio_mmap(struct file *filp, struct kobject *kobj,
93 			struct bin_attribute *bin_attr,
94 			struct vm_area_struct *vma)
95 {
96 	struct ocxl_afu *afu = to_afu(kobj_to_dev(kobj));
97 
98 	if ((vma_pages(vma) + vma->vm_pgoff) >
99 		(afu->config.global_mmio_size >> PAGE_SHIFT))
100 		return -EINVAL;
101 
102 	vma->vm_flags |= VM_IO | VM_PFNMAP;
103 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
104 	vma->vm_ops = &global_mmio_vmops;
105 	vma->vm_private_data = afu;
106 	return 0;
107 }
108 
109 int ocxl_sysfs_register_afu(struct ocxl_file_info *info)
110 {
111 	int i, rc;
112 
113 	for (i = 0; i < ARRAY_SIZE(afu_attrs); i++) {
114 		rc = device_create_file(&info->dev, &afu_attrs[i]);
115 		if (rc)
116 			goto err;
117 	}
118 
119 	sysfs_attr_init(&info->attr_global_mmio.attr);
120 	info->attr_global_mmio.attr.name = "global_mmio_area";
121 	info->attr_global_mmio.attr.mode = 0600;
122 	info->attr_global_mmio.size = info->afu->config.global_mmio_size;
123 	info->attr_global_mmio.read = global_mmio_read;
124 	info->attr_global_mmio.mmap = global_mmio_mmap;
125 	rc = device_create_bin_file(&info->dev, &info->attr_global_mmio);
126 	if (rc) {
127 		dev_err(&info->dev, "Unable to create global mmio attr for afu: %d\n", rc);
128 		goto err;
129 	}
130 
131 	return 0;
132 
133 err:
134 	for (i--; i >= 0; i--)
135 		device_remove_file(&info->dev, &afu_attrs[i]);
136 
137 	return rc;
138 }
139 
140 void ocxl_sysfs_unregister_afu(struct ocxl_file_info *info)
141 {
142 	int i;
143 
144 	/*
145 	 * device_remove_bin_file is safe to call if the file is not added as
146 	 * the files are removed by name, and early exit if not found
147 	 */
148 	for (i = 0; i < ARRAY_SIZE(afu_attrs); i++)
149 		device_remove_file(&info->dev, &afu_attrs[i]);
150 	device_remove_bin_file(&info->dev, &info->attr_global_mmio);
151 }
152