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
nubus_devices_proc_show(struct seq_file * m,void * v)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  
nubus_proc_add_board(struct nubus_board * board)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  
nubus_proc_add_rsrc_dir(struct proc_dir_entry * procdir,const struct nubus_dirent * ent,struct nubus_board * board)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 *
nubus_proc_alloc_pde_data(unsigned char * ptr,unsigned int size)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  
nubus_proc_rsrc_show(struct seq_file * m,void * v)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  
nubus_proc_add_rsrc_mem(struct proc_dir_entry * procdir,const struct nubus_dirent * ent,unsigned int size)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  
nubus_proc_add_rsrc(struct proc_dir_entry * procdir,const struct nubus_dirent * ent)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  
nubus_proc_init(void)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