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
36static int
37nubus_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
48static struct proc_dir_entry *proc_bus_nubus_dir;
49
50/*
51 * /proc/bus/nubus/x/ stuff
52 */
53
54struct proc_dir_entry *nubus_proc_add_board(struct nubus_board *board)
55{
56	char name[2];
57
58	if (!proc_bus_nubus_dir || !nubus_populate_procfs)
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
68struct 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 || !nubus_populate_procfs)
76		return NULL;
77	snprintf(name, sizeof(name), "%x", ent->type);
78	remove_proc_subtree(name, procdir);
79	return proc_mkdir_data(name, 0555, procdir, (void *)lanes);
80}
81
82/* The PDE private data for a file under /proc/bus/nubus/x/ is a pointer to
83 * an instance of the following structure, which gives the location and size
84 * of the resource data in the slot ROM. For slot resources which hold only a
85 * small integer, this integer value is stored directly and size is set to 0.
86 * A NULL private data pointer indicates an unrecognized resource.
87 */
88
89struct nubus_proc_pde_data {
90	unsigned char *res_ptr;
91	unsigned int res_size;
92};
93
94static struct nubus_proc_pde_data *
95nubus_proc_alloc_pde_data(unsigned char *ptr, unsigned int size)
96{
97	struct nubus_proc_pde_data *pded;
98
99	pded = kmalloc(sizeof(*pded), GFP_KERNEL);
100	if (!pded)
101		return NULL;
102
103	pded->res_ptr = ptr;
104	pded->res_size = size;
105	return pded;
106}
107
108static int nubus_proc_rsrc_show(struct seq_file *m, void *v)
109{
110	struct inode *inode = m->private;
111	struct nubus_proc_pde_data *pded;
112
113	pded = pde_data(inode);
114	if (!pded)
115		return 0;
116
117	if (pded->res_size > m->size)
118		return -EFBIG;
119
120	if (pded->res_size) {
121		int lanes = (int)proc_get_parent_data(inode);
122		struct nubus_dirent ent;
123
124		if (!lanes)
125			return 0;
126
127		ent.mask = lanes;
128		ent.base = pded->res_ptr;
129		ent.data = 0;
130		nubus_seq_write_rsrc_mem(m, &ent, pded->res_size);
131	} else {
132		unsigned int data = (unsigned int)pded->res_ptr;
133
134		seq_putc(m, data >> 16);
135		seq_putc(m, data >> 8);
136		seq_putc(m, data >> 0);
137	}
138	return 0;
139}
140
141static int nubus_rsrc_proc_open(struct inode *inode, struct file *file)
142{
143	return single_open(file, nubus_proc_rsrc_show, inode);
144}
145
146static const struct proc_ops nubus_rsrc_proc_ops = {
147	.proc_open	= nubus_rsrc_proc_open,
148	.proc_read	= seq_read,
149	.proc_lseek	= seq_lseek,
150	.proc_release	= single_release,
151};
152
153void nubus_proc_add_rsrc_mem(struct proc_dir_entry *procdir,
154			     const struct nubus_dirent *ent,
155			     unsigned int size)
156{
157	char name[9];
158	struct nubus_proc_pde_data *pded;
159
160	if (!procdir || !nubus_populate_procfs)
161		return;
162
163	snprintf(name, sizeof(name), "%x", ent->type);
164	if (size)
165		pded = nubus_proc_alloc_pde_data(nubus_dirptr(ent), size);
166	else
167		pded = NULL;
168	remove_proc_subtree(name, procdir);
169	proc_create_data(name, S_IFREG | 0444, procdir,
170			 &nubus_rsrc_proc_ops, pded);
171}
172
173void nubus_proc_add_rsrc(struct proc_dir_entry *procdir,
174			 const struct nubus_dirent *ent)
175{
176	char name[9];
177	unsigned char *data = (unsigned char *)ent->data;
178
179	if (!procdir || !nubus_populate_procfs)
180		return;
181
182	snprintf(name, sizeof(name), "%x", ent->type);
183	remove_proc_subtree(name, procdir);
184	proc_create_data(name, S_IFREG | 0444, procdir,
185			 &nubus_rsrc_proc_ops,
186			 nubus_proc_alloc_pde_data(data, 0));
187}
188
189/*
190 * /proc/nubus stuff
191 */
192
193void __init nubus_proc_init(void)
194{
195	proc_create_single("nubus", 0, NULL, nubus_proc_show);
196	proc_bus_nubus_dir = proc_mkdir("bus/nubus", NULL);
197	if (!proc_bus_nubus_dir)
198		return;
199	proc_create_single("devices", 0, proc_bus_nubus_dir,
200			nubus_devices_proc_show);
201}
202