xref: /openbmc/linux/drivers/nubus/proc.c (revision e2c75e76)
1 // SPDX-License-Identifier: GPL-2.0
2 /* drivers/nubus/proc.c: Proc FS interface for NuBus.
3 
4    By David Huggins-Daines <dhd@debian.org>
5 
6    Much code and many ideas from drivers/pci/proc.c:
7    Copyright (c) 1997, 1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
8 
9    This is initially based on the Zorro and PCI interfaces.  However,
10    it works somewhat differently.  The intent is to provide a
11    structure in /proc analogous to the structure of the NuBus ROM
12    resources.
13 
14    Therefore each board function gets a directory, which may in turn
15    contain subdirectories.  Each slot resource is a file.  Unrecognized
16    resources are empty files, since every resource ID requires a special
17    case (e.g. if the resource ID implies a directory or block, then its
18    value has to be interpreted as a slot ROM pointer etc.).
19  */
20 
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/nubus.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/slab.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/uaccess.h>
30 #include <asm/byteorder.h>
31 
32 /*
33  * /proc/bus/nubus/devices stuff
34  */
35 
36 static int
37 nubus_devices_proc_show(struct seq_file *m, void *v)
38 {
39 	struct nubus_rsrc *fres;
40 
41 	for_each_func_rsrc(fres)
42 		seq_printf(m, "%x\t%04x %04x %04x %04x\t%08lx\n",
43 			   fres->board->slot, fres->category, fres->type,
44 			   fres->dr_sw, fres->dr_hw, fres->board->slot_addr);
45 	return 0;
46 }
47 
48 static int nubus_devices_proc_open(struct inode *inode, struct file *file)
49 {
50 	return single_open(file, nubus_devices_proc_show, NULL);
51 }
52 
53 static const struct file_operations nubus_devices_proc_fops = {
54 	.open		= nubus_devices_proc_open,
55 	.read		= seq_read,
56 	.llseek		= seq_lseek,
57 	.release	= single_release,
58 };
59 
60 static struct proc_dir_entry *proc_bus_nubus_dir;
61 
62 /*
63  * /proc/bus/nubus/x/ stuff
64  */
65 
66 struct proc_dir_entry *nubus_proc_add_board(struct nubus_board *board)
67 {
68 	char name[2];
69 
70 	if (!proc_bus_nubus_dir)
71 		return NULL;
72 	snprintf(name, sizeof(name), "%x", board->slot);
73 	return proc_mkdir(name, proc_bus_nubus_dir);
74 }
75 
76 /* The PDE private data for any directory under /proc/bus/nubus/x/
77  * is the bytelanes value for the board in slot x.
78  */
79 
80 struct proc_dir_entry *nubus_proc_add_rsrc_dir(struct proc_dir_entry *procdir,
81 					       const struct nubus_dirent *ent,
82 					       struct nubus_board *board)
83 {
84 	char name[9];
85 	int lanes = board->lanes;
86 
87 	if (!procdir)
88 		return NULL;
89 	snprintf(name, sizeof(name), "%x", ent->type);
90 	return proc_mkdir_data(name, 0555, procdir, (void *)lanes);
91 }
92 
93 /* The PDE private data for a file under /proc/bus/nubus/x/ is a pointer to
94  * an instance of the following structure, which gives the location and size
95  * of the resource data in the slot ROM. For slot resources which hold only a
96  * small integer, this integer value is stored directly and size is set to 0.
97  * A NULL private data pointer indicates an unrecognized resource.
98  */
99 
100 struct nubus_proc_pde_data {
101 	unsigned char *res_ptr;
102 	unsigned int res_size;
103 };
104 
105 static struct nubus_proc_pde_data *
106 nubus_proc_alloc_pde_data(unsigned char *ptr, unsigned int size)
107 {
108 	struct nubus_proc_pde_data *pde_data;
109 
110 	pde_data = kmalloc(sizeof(*pde_data), GFP_KERNEL);
111 	if (!pde_data)
112 		return NULL;
113 
114 	pde_data->res_ptr = ptr;
115 	pde_data->res_size = size;
116 	return pde_data;
117 }
118 
119 static int nubus_proc_rsrc_show(struct seq_file *m, void *v)
120 {
121 	struct inode *inode = m->private;
122 	struct nubus_proc_pde_data *pde_data;
123 
124 	pde_data = PDE_DATA(inode);
125 	if (!pde_data)
126 		return 0;
127 
128 	if (pde_data->res_size > m->size)
129 		return -EFBIG;
130 
131 	if (pde_data->res_size) {
132 		int lanes = (int)proc_get_parent_data(inode);
133 		struct nubus_dirent ent;
134 
135 		if (!lanes)
136 			return 0;
137 
138 		ent.mask = lanes;
139 		ent.base = pde_data->res_ptr;
140 		ent.data = 0;
141 		nubus_seq_write_rsrc_mem(m, &ent, pde_data->res_size);
142 	} else {
143 		unsigned int data = (unsigned int)pde_data->res_ptr;
144 
145 		seq_putc(m, data >> 16);
146 		seq_putc(m, data >> 8);
147 		seq_putc(m, data >> 0);
148 	}
149 	return 0;
150 }
151 
152 static int nubus_proc_rsrc_open(struct inode *inode, struct file *file)
153 {
154 	return single_open(file, nubus_proc_rsrc_show, inode);
155 }
156 
157 static const struct file_operations nubus_proc_rsrc_fops = {
158 	.open		= nubus_proc_rsrc_open,
159 	.read		= seq_read,
160 	.llseek		= seq_lseek,
161 	.release	= single_release,
162 };
163 
164 void nubus_proc_add_rsrc_mem(struct proc_dir_entry *procdir,
165 			     const struct nubus_dirent *ent,
166 			     unsigned int size)
167 {
168 	char name[9];
169 	struct nubus_proc_pde_data *pde_data;
170 
171 	if (!procdir)
172 		return;
173 
174 	snprintf(name, sizeof(name), "%x", ent->type);
175 	if (size)
176 		pde_data = nubus_proc_alloc_pde_data(nubus_dirptr(ent), size);
177 	else
178 		pde_data = NULL;
179 	proc_create_data(name, S_IFREG | 0444, procdir,
180 			 &nubus_proc_rsrc_fops, pde_data);
181 }
182 
183 void nubus_proc_add_rsrc(struct proc_dir_entry *procdir,
184 			 const struct nubus_dirent *ent)
185 {
186 	char name[9];
187 	unsigned char *data = (unsigned char *)ent->data;
188 
189 	if (!procdir)
190 		return;
191 
192 	snprintf(name, sizeof(name), "%x", ent->type);
193 	proc_create_data(name, S_IFREG | 0444, procdir,
194 			 &nubus_proc_rsrc_fops,
195 			 nubus_proc_alloc_pde_data(data, 0));
196 }
197 
198 /*
199  * /proc/nubus stuff
200  */
201 
202 static int nubus_proc_open(struct inode *inode, struct file *file)
203 {
204 	return single_open(file, nubus_proc_show, NULL);
205 }
206 
207 static const struct file_operations nubus_proc_fops = {
208 	.open		= nubus_proc_open,
209 	.read		= seq_read,
210 	.llseek		= seq_lseek,
211 	.release	= single_release,
212 };
213 
214 void __init nubus_proc_init(void)
215 {
216 	proc_create("nubus", 0, NULL, &nubus_proc_fops);
217 	proc_bus_nubus_dir = proc_mkdir("bus/nubus", NULL);
218 	if (!proc_bus_nubus_dir)
219 		return;
220 	proc_create("devices", 0, proc_bus_nubus_dir, &nubus_devices_proc_fops);
221 }
222