xref: /openbmc/linux/drivers/nubus/proc.c (revision fb574682)
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 struct proc_dir_entry *proc_bus_nubus_dir;
49 
50 /*
51  * /proc/bus/nubus/x/ stuff
52  */
53 
54 struct proc_dir_entry *nubus_proc_add_board(struct nubus_board *board)
55 {
56 	char name[2];
57 
58 	if (!proc_bus_nubus_dir)
59 		return NULL;
60 	snprintf(name, sizeof(name), "%x", board->slot);
61 	return proc_mkdir(name, proc_bus_nubus_dir);
62 }
63 
64 /* The PDE private data for any directory under /proc/bus/nubus/x/
65  * is the bytelanes value for the board in slot x.
66  */
67 
68 struct proc_dir_entry *nubus_proc_add_rsrc_dir(struct proc_dir_entry *procdir,
69 					       const struct nubus_dirent *ent,
70 					       struct nubus_board *board)
71 {
72 	char name[9];
73 	int lanes = board->lanes;
74 
75 	if (!procdir)
76 		return NULL;
77 	snprintf(name, sizeof(name), "%x", ent->type);
78 	return proc_mkdir_data(name, 0555, procdir, (void *)lanes);
79 }
80 
81 /* The PDE private data for a file under /proc/bus/nubus/x/ is a pointer to
82  * an instance of the following structure, which gives the location and size
83  * of the resource data in the slot ROM. For slot resources which hold only a
84  * small integer, this integer value is stored directly and size is set to 0.
85  * A NULL private data pointer indicates an unrecognized resource.
86  */
87 
88 struct nubus_proc_pde_data {
89 	unsigned char *res_ptr;
90 	unsigned int res_size;
91 };
92 
93 static struct nubus_proc_pde_data *
94 nubus_proc_alloc_pde_data(unsigned char *ptr, unsigned int size)
95 {
96 	struct nubus_proc_pde_data *pde_data;
97 
98 	pde_data = kmalloc(sizeof(*pde_data), GFP_KERNEL);
99 	if (!pde_data)
100 		return NULL;
101 
102 	pde_data->res_ptr = ptr;
103 	pde_data->res_size = size;
104 	return pde_data;
105 }
106 
107 static int nubus_proc_rsrc_show(struct seq_file *m, void *v)
108 {
109 	struct inode *inode = m->private;
110 	struct nubus_proc_pde_data *pde_data;
111 
112 	pde_data = PDE_DATA(inode);
113 	if (!pde_data)
114 		return 0;
115 
116 	if (pde_data->res_size > m->size)
117 		return -EFBIG;
118 
119 	if (pde_data->res_size) {
120 		int lanes = (int)proc_get_parent_data(inode);
121 		struct nubus_dirent ent;
122 
123 		if (!lanes)
124 			return 0;
125 
126 		ent.mask = lanes;
127 		ent.base = pde_data->res_ptr;
128 		ent.data = 0;
129 		nubus_seq_write_rsrc_mem(m, &ent, pde_data->res_size);
130 	} else {
131 		unsigned int data = (unsigned int)pde_data->res_ptr;
132 
133 		seq_putc(m, data >> 16);
134 		seq_putc(m, data >> 8);
135 		seq_putc(m, data >> 0);
136 	}
137 	return 0;
138 }
139 
140 void nubus_proc_add_rsrc_mem(struct proc_dir_entry *procdir,
141 			     const struct nubus_dirent *ent,
142 			     unsigned int size)
143 {
144 	char name[9];
145 	struct nubus_proc_pde_data *pde_data;
146 
147 	if (!procdir)
148 		return;
149 
150 	snprintf(name, sizeof(name), "%x", ent->type);
151 	if (size)
152 		pde_data = nubus_proc_alloc_pde_data(nubus_dirptr(ent), size);
153 	else
154 		pde_data = NULL;
155 	proc_create_single_data(name, S_IFREG | 0444, procdir,
156 			nubus_proc_rsrc_show, pde_data);
157 }
158 
159 void nubus_proc_add_rsrc(struct proc_dir_entry *procdir,
160 			 const struct nubus_dirent *ent)
161 {
162 	char name[9];
163 	unsigned char *data = (unsigned char *)ent->data;
164 
165 	if (!procdir)
166 		return;
167 
168 	snprintf(name, sizeof(name), "%x", ent->type);
169 	proc_create_single_data(name, S_IFREG | 0444, procdir,
170 			nubus_proc_rsrc_show,
171 			nubus_proc_alloc_pde_data(data, 0));
172 }
173 
174 /*
175  * /proc/nubus stuff
176  */
177 
178 void __init nubus_proc_init(void)
179 {
180 	proc_create_single("nubus", 0, NULL, nubus_proc_show);
181 	proc_bus_nubus_dir = proc_mkdir("bus/nubus", NULL);
182 	if (!proc_bus_nubus_dir)
183 		return;
184 	proc_create_single("devices", 0, proc_bus_nubus_dir,
185 			nubus_devices_proc_show);
186 }
187