linux/drivers/nubus/proc.c
Finn Thain 72b44f6577 nubus: Don't list slot resources by default
Some Nubus card ROMs contain many slot resources. A single Radius video
card produced well over a thousand entries under /proc/bus/nubus/.
Populating /proc/bus/nubus/ on a slow machine with several such cards
installed takes long enough that the user may think that the system is
wedged. All those procfs entries also consume significant RAM though
they are not normally needed (except by developers).
Omit these resources from /proc/bus/nubus/ by default and add a kernel
parameter to enable them when needed.
On the test machine, this saved 300 kB and 10 seconds.

Cc: Brad Boyer <flar@allandria.com>
Reviewed-by: Brad Boyer <flar@allandria.com>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/71ed7fb234a5f7381a50253b0d841a656d53e64c.1684200125.git.fthain@linux-m68k.org
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2023-05-22 13:51:56 +02:00

202 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* drivers/nubus/proc.c: Proc FS interface for NuBus.
By David Huggins-Daines <dhd@debian.org>
Much code and many ideas from drivers/pci/proc.c:
Copyright (c) 1997, 1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
This is initially based on the Zorro and PCI interfaces. However,
it works somewhat differently. The intent is to provide a
structure in /proc analogous to the structure of the NuBus ROM
resources.
Therefore each board function gets a directory, which may in turn
contain subdirectories. Each slot resource is a file. Unrecognized
resources are empty files, since every resource ID requires a special
case (e.g. if the resource ID implies a directory or block, then its
value has to be interpreted as a slot ROM pointer etc.).
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/nubus.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/byteorder.h>
/*
* /proc/bus/nubus/devices stuff
*/
static int
nubus_devices_proc_show(struct seq_file *m, void *v)
{
struct nubus_rsrc *fres;
for_each_func_rsrc(fres)
seq_printf(m, "%x\t%04x %04x %04x %04x\t%08lx\n",
fres->board->slot, fres->category, fres->type,
fres->dr_sw, fres->dr_hw, fres->board->slot_addr);
return 0;
}
static struct proc_dir_entry *proc_bus_nubus_dir;
/*
* /proc/bus/nubus/x/ stuff
*/
struct proc_dir_entry *nubus_proc_add_board(struct nubus_board *board)
{
char name[2];
if (!proc_bus_nubus_dir || !nubus_populate_procfs)
return NULL;
snprintf(name, sizeof(name), "%x", board->slot);
return proc_mkdir(name, proc_bus_nubus_dir);
}
/* The PDE private data for any directory under /proc/bus/nubus/x/
* is the bytelanes value for the board in slot x.
*/
struct proc_dir_entry *nubus_proc_add_rsrc_dir(struct proc_dir_entry *procdir,
const struct nubus_dirent *ent,
struct nubus_board *board)
{
char name[9];
int lanes = board->lanes;
if (!procdir || !nubus_populate_procfs)
return NULL;
snprintf(name, sizeof(name), "%x", ent->type);
remove_proc_subtree(name, procdir);
return proc_mkdir_data(name, 0555, procdir, (void *)lanes);
}
/* The PDE private data for a file under /proc/bus/nubus/x/ is a pointer to
* an instance of the following structure, which gives the location and size
* of the resource data in the slot ROM. For slot resources which hold only a
* small integer, this integer value is stored directly and size is set to 0.
* A NULL private data pointer indicates an unrecognized resource.
*/
struct nubus_proc_pde_data {
unsigned char *res_ptr;
unsigned int res_size;
};
static struct nubus_proc_pde_data *
nubus_proc_alloc_pde_data(unsigned char *ptr, unsigned int size)
{
struct nubus_proc_pde_data *pded;
pded = kmalloc(sizeof(*pded), GFP_KERNEL);
if (!pded)
return NULL;
pded->res_ptr = ptr;
pded->res_size = size;
return pded;
}
static int nubus_proc_rsrc_show(struct seq_file *m, void *v)
{
struct inode *inode = m->private;
struct nubus_proc_pde_data *pded;
pded = pde_data(inode);
if (!pded)
return 0;
if (pded->res_size > m->size)
return -EFBIG;
if (pded->res_size) {
int lanes = (int)proc_get_parent_data(inode);
struct nubus_dirent ent;
if (!lanes)
return 0;
ent.mask = lanes;
ent.base = pded->res_ptr;
ent.data = 0;
nubus_seq_write_rsrc_mem(m, &ent, pded->res_size);
} else {
unsigned int data = (unsigned int)pded->res_ptr;
seq_putc(m, data >> 16);
seq_putc(m, data >> 8);
seq_putc(m, data >> 0);
}
return 0;
}
static int nubus_rsrc_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, nubus_proc_rsrc_show, inode);
}
static const struct proc_ops nubus_rsrc_proc_ops = {
.proc_open = nubus_rsrc_proc_open,
.proc_read = seq_read,
.proc_lseek = seq_lseek,
.proc_release = single_release,
};
void nubus_proc_add_rsrc_mem(struct proc_dir_entry *procdir,
const struct nubus_dirent *ent,
unsigned int size)
{
char name[9];
struct nubus_proc_pde_data *pded;
if (!procdir || !nubus_populate_procfs)
return;
snprintf(name, sizeof(name), "%x", ent->type);
if (size)
pded = nubus_proc_alloc_pde_data(nubus_dirptr(ent), size);
else
pded = NULL;
remove_proc_subtree(name, procdir);
proc_create_data(name, S_IFREG | 0444, procdir,
&nubus_rsrc_proc_ops, pded);
}
void nubus_proc_add_rsrc(struct proc_dir_entry *procdir,
const struct nubus_dirent *ent)
{
char name[9];
unsigned char *data = (unsigned char *)ent->data;
if (!procdir || !nubus_populate_procfs)
return;
snprintf(name, sizeof(name), "%x", ent->type);
remove_proc_subtree(name, procdir);
proc_create_data(name, S_IFREG | 0444, procdir,
&nubus_rsrc_proc_ops,
nubus_proc_alloc_pde_data(data, 0));
}
/*
* /proc/nubus stuff
*/
void __init nubus_proc_init(void)
{
proc_create_single("nubus", 0, NULL, nubus_proc_show);
proc_bus_nubus_dir = proc_mkdir("bus/nubus", NULL);
if (!proc_bus_nubus_dir)
return;
proc_create_single("devices", 0, proc_bus_nubus_dir,
nubus_devices_proc_show);
}