xref: /openbmc/linux/drivers/misc/ocxl/sysfs.c (revision e2c75e76)
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 ssize_t global_mmio_size_show(struct device *device,
7 				struct device_attribute *attr,
8 				char *buf)
9 {
10 	struct ocxl_afu *afu = to_ocxl_afu(device);
11 
12 	return scnprintf(buf, PAGE_SIZE, "%d\n",
13 			afu->config.global_mmio_size);
14 }
15 
16 static ssize_t pp_mmio_size_show(struct device *device,
17 				struct device_attribute *attr,
18 				char *buf)
19 {
20 	struct ocxl_afu *afu = to_ocxl_afu(device);
21 
22 	return scnprintf(buf, PAGE_SIZE, "%d\n",
23 			afu->config.pp_mmio_stride);
24 }
25 
26 static ssize_t afu_version_show(struct device *device,
27 				struct device_attribute *attr,
28 				char *buf)
29 {
30 	struct ocxl_afu *afu = to_ocxl_afu(device);
31 
32 	return scnprintf(buf, PAGE_SIZE, "%hhu:%hhu\n",
33 			afu->config.version_major,
34 			afu->config.version_minor);
35 }
36 
37 static ssize_t contexts_show(struct device *device,
38 		struct device_attribute *attr,
39 		char *buf)
40 {
41 	struct ocxl_afu *afu = to_ocxl_afu(device);
42 
43 	return scnprintf(buf, PAGE_SIZE, "%d/%d\n",
44 			afu->pasid_count, afu->pasid_max);
45 }
46 
47 static struct device_attribute afu_attrs[] = {
48 	__ATTR_RO(global_mmio_size),
49 	__ATTR_RO(pp_mmio_size),
50 	__ATTR_RO(afu_version),
51 	__ATTR_RO(contexts),
52 };
53 
54 static ssize_t global_mmio_read(struct file *filp, struct kobject *kobj,
55 				struct bin_attribute *bin_attr, char *buf,
56 				loff_t off, size_t count)
57 {
58 	struct ocxl_afu *afu = to_ocxl_afu(kobj_to_dev(kobj));
59 
60 	if (count == 0 || off < 0 ||
61 		off >= afu->config.global_mmio_size)
62 		return 0;
63 	memcpy_fromio(buf, afu->global_mmio_ptr + off, count);
64 	return count;
65 }
66 
67 static int global_mmio_fault(struct vm_fault *vmf)
68 {
69 	struct vm_area_struct *vma = vmf->vma;
70 	struct ocxl_afu *afu = vma->vm_private_data;
71 	unsigned long offset;
72 
73 	if (vmf->pgoff >= (afu->config.global_mmio_size >> PAGE_SHIFT))
74 		return VM_FAULT_SIGBUS;
75 
76 	offset = vmf->pgoff;
77 	offset += (afu->global_mmio_start >> PAGE_SHIFT);
78 	vm_insert_pfn(vma, vmf->address, offset);
79 	return VM_FAULT_NOPAGE;
80 }
81 
82 static const struct vm_operations_struct global_mmio_vmops = {
83 	.fault = global_mmio_fault,
84 };
85 
86 static int global_mmio_mmap(struct file *filp, struct kobject *kobj,
87 			struct bin_attribute *bin_attr,
88 			struct vm_area_struct *vma)
89 {
90 	struct ocxl_afu *afu = to_ocxl_afu(kobj_to_dev(kobj));
91 
92 	if ((vma_pages(vma) + vma->vm_pgoff) >
93 		(afu->config.global_mmio_size >> PAGE_SHIFT))
94 		return -EINVAL;
95 
96 	vma->vm_flags |= VM_IO | VM_PFNMAP;
97 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
98 	vma->vm_ops = &global_mmio_vmops;
99 	vma->vm_private_data = afu;
100 	return 0;
101 }
102 
103 int ocxl_sysfs_add_afu(struct ocxl_afu *afu)
104 {
105 	int i, rc;
106 
107 	for (i = 0; i < ARRAY_SIZE(afu_attrs); i++) {
108 		rc = device_create_file(&afu->dev, &afu_attrs[i]);
109 		if (rc)
110 			goto err;
111 	}
112 
113 	sysfs_attr_init(&afu->attr_global_mmio.attr);
114 	afu->attr_global_mmio.attr.name = "global_mmio_area";
115 	afu->attr_global_mmio.attr.mode = 0600;
116 	afu->attr_global_mmio.size = afu->config.global_mmio_size;
117 	afu->attr_global_mmio.read = global_mmio_read;
118 	afu->attr_global_mmio.mmap = global_mmio_mmap;
119 	rc = device_create_bin_file(&afu->dev, &afu->attr_global_mmio);
120 	if (rc) {
121 		dev_err(&afu->dev,
122 			"Unable to create global mmio attr for afu: %d\n",
123 			rc);
124 		goto err;
125 	}
126 
127 	return 0;
128 
129 err:
130 	for (i--; i >= 0; i--)
131 		device_remove_file(&afu->dev, &afu_attrs[i]);
132 	return rc;
133 }
134 
135 void ocxl_sysfs_remove_afu(struct ocxl_afu *afu)
136 {
137 	int i;
138 
139 	for (i = 0; i < ARRAY_SIZE(afu_attrs); i++)
140 		device_remove_file(&afu->dev, &afu_attrs[i]);
141 	device_remove_bin_file(&afu->dev, &afu->attr_global_mmio);
142 }
143