linux/drivers/parport/procfs.c
Joel Granados 2f2665c13a sysctl: replace child with an enumeration
This is part of the effort to remove the empty element at the end of
ctl_table structs. "child" was a deprecated elem in this struct and was
being used to differentiate between two types of ctl_tables: "normal"
and "permanently emtpy".

What changed?:
* Replace "child" with an enumeration that will have two values: the
  default (0) and the permanently empty (1). The latter is left at zero
  so when struct ctl_table is created with kzalloc or in a local
  context, it will have the zero value by default. We document the
  new enum with kdoc.
* Remove the "empty child" check from sysctl_check_table
* Remove count_subheaders function as there is no longer a need to
  calculate how many headers there are for every child
* Remove the recursive call to unregister_sysctl_table as there is no
  need to traverse down the child tree any longer
* Add a new SYSCTL_PERM_EMPTY_DIR binary flag
* Remove the last remanence of child from partport/procfs.c

Signed-off-by: Joel Granados <j.granados@samsung.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
2023-06-18 02:32:54 -07:00

639 lines
13 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Sysctl interface for parport devices.
*
* Authors: David Campbell
* Tim Waugh <tim@cyberelk.demon.co.uk>
* Philip Blundell <philb@gnu.org>
* Andrea Arcangeli
* Riccardo Facchetti <fizban@tin.it>
*
* based on work by Grant Guenther <grant@torque.net>
* and Philip Blundell
*
* Cleaned up include files - Russell King <linux@arm.uk.linux.org>
*/
#include <linux/string.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/parport.h>
#include <linux/ctype.h>
#include <linux/sysctl.h>
#include <linux/device.h>
#include <linux/uaccess.h>
#if defined(CONFIG_SYSCTL) && defined(CONFIG_PROC_FS)
#define PARPORT_MIN_TIMESLICE_VALUE 1ul
#define PARPORT_MAX_TIMESLICE_VALUE ((unsigned long) HZ)
#define PARPORT_MIN_SPINTIME_VALUE 1
#define PARPORT_MAX_SPINTIME_VALUE 1000
/*
* PARPORT_BASE_* is the size of the known parts of the sysctl path
* in dev/partport/%s/devices/%s. "dev/parport/"(12), "/devices/"(9
* and null char(1).
*/
#define PARPORT_BASE_PATH_SIZE 13
#define PARPORT_BASE_DEVICES_PATH_SIZE 22
static int do_active_device(struct ctl_table *table, int write,
void *result, size_t *lenp, loff_t *ppos)
{
struct parport *port = (struct parport *)table->extra1;
char buffer[256];
struct pardevice *dev;
int len = 0;
if (write) /* can't happen anyway */
return -EACCES;
if (*ppos) {
*lenp = 0;
return 0;
}
for (dev = port->devices; dev ; dev = dev->next) {
if(dev == port->cad) {
len += sprintf(buffer, "%s\n", dev->name);
}
}
if(!len) {
len += sprintf(buffer, "%s\n", "none");
}
if (len > *lenp)
len = *lenp;
else
*lenp = len;
*ppos += len;
memcpy(result, buffer, len);
return 0;
}
#ifdef CONFIG_PARPORT_1284
static int do_autoprobe(struct ctl_table *table, int write,
void *result, size_t *lenp, loff_t *ppos)
{
struct parport_device_info *info = table->extra2;
const char *str;
char buffer[256];
int len = 0;
if (write) /* permissions stop this */
return -EACCES;
if (*ppos) {
*lenp = 0;
return 0;
}
if ((str = info->class_name) != NULL)
len += sprintf (buffer + len, "CLASS:%s;\n", str);
if ((str = info->model) != NULL)
len += sprintf (buffer + len, "MODEL:%s;\n", str);
if ((str = info->mfr) != NULL)
len += sprintf (buffer + len, "MANUFACTURER:%s;\n", str);
if ((str = info->description) != NULL)
len += sprintf (buffer + len, "DESCRIPTION:%s;\n", str);
if ((str = info->cmdset) != NULL)
len += sprintf (buffer + len, "COMMAND SET:%s;\n", str);
if (len > *lenp)
len = *lenp;
else
*lenp = len;
*ppos += len;
memcpy(result, buffer, len);
return 0;
}
#endif /* IEEE1284.3 support. */
static int do_hardware_base_addr(struct ctl_table *table, int write,
void *result, size_t *lenp, loff_t *ppos)
{
struct parport *port = (struct parport *)table->extra1;
char buffer[20];
int len = 0;
if (*ppos) {
*lenp = 0;
return 0;
}
if (write) /* permissions prevent this anyway */
return -EACCES;
len += sprintf (buffer, "%lu\t%lu\n", port->base, port->base_hi);
if (len > *lenp)
len = *lenp;
else
*lenp = len;
*ppos += len;
memcpy(result, buffer, len);
return 0;
}
static int do_hardware_irq(struct ctl_table *table, int write,
void *result, size_t *lenp, loff_t *ppos)
{
struct parport *port = (struct parport *)table->extra1;
char buffer[20];
int len = 0;
if (*ppos) {
*lenp = 0;
return 0;
}
if (write) /* permissions prevent this anyway */
return -EACCES;
len += sprintf (buffer, "%d\n", port->irq);
if (len > *lenp)
len = *lenp;
else
*lenp = len;
*ppos += len;
memcpy(result, buffer, len);
return 0;
}
static int do_hardware_dma(struct ctl_table *table, int write,
void *result, size_t *lenp, loff_t *ppos)
{
struct parport *port = (struct parport *)table->extra1;
char buffer[20];
int len = 0;
if (*ppos) {
*lenp = 0;
return 0;
}
if (write) /* permissions prevent this anyway */
return -EACCES;
len += sprintf (buffer, "%d\n", port->dma);
if (len > *lenp)
len = *lenp;
else
*lenp = len;
*ppos += len;
memcpy(result, buffer, len);
return 0;
}
static int do_hardware_modes(struct ctl_table *table, int write,
void *result, size_t *lenp, loff_t *ppos)
{
struct parport *port = (struct parport *)table->extra1;
char buffer[40];
int len = 0;
if (*ppos) {
*lenp = 0;
return 0;
}
if (write) /* permissions prevent this anyway */
return -EACCES;
{
#define printmode(x) \
do { \
if (port->modes & PARPORT_MODE_##x) \
len += sprintf(buffer + len, "%s%s", f++ ? "," : "", #x); \
} while (0)
int f = 0;
printmode(PCSPP);
printmode(TRISTATE);
printmode(COMPAT);
printmode(EPP);
printmode(ECP);
printmode(DMA);
#undef printmode
}
buffer[len++] = '\n';
if (len > *lenp)
len = *lenp;
else
*lenp = len;
*ppos += len;
memcpy(result, buffer, len);
return 0;
}
static const unsigned long parport_min_timeslice_value =
PARPORT_MIN_TIMESLICE_VALUE;
static const unsigned long parport_max_timeslice_value =
PARPORT_MAX_TIMESLICE_VALUE;
static const int parport_min_spintime_value =
PARPORT_MIN_SPINTIME_VALUE;
static const int parport_max_spintime_value =
PARPORT_MAX_SPINTIME_VALUE;
struct parport_sysctl_table {
struct ctl_table_header *port_header;
struct ctl_table_header *devices_header;
struct ctl_table vars[12];
struct ctl_table device_dir[2];
};
static const struct parport_sysctl_table parport_sysctl_template = {
.port_header = NULL,
.devices_header = NULL,
{
{
.procname = "spintime",
.data = NULL,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = (void*) &parport_min_spintime_value,
.extra2 = (void*) &parport_max_spintime_value
},
{
.procname = "base-addr",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_hardware_base_addr
},
{
.procname = "irq",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_hardware_irq
},
{
.procname = "dma",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_hardware_dma
},
{
.procname = "modes",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_hardware_modes
},
#ifdef CONFIG_PARPORT_1284
{
.procname = "autoprobe",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_autoprobe
},
{
.procname = "autoprobe0",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_autoprobe
},
{
.procname = "autoprobe1",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_autoprobe
},
{
.procname = "autoprobe2",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_autoprobe
},
{
.procname = "autoprobe3",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_autoprobe
},
#endif /* IEEE 1284 support */
{}
},
{
{
.procname = "active",
.data = NULL,
.maxlen = 0,
.mode = 0444,
.proc_handler = do_active_device
},
{}
},
};
struct parport_device_sysctl_table
{
struct ctl_table_header *sysctl_header;
struct ctl_table vars[2];
struct ctl_table device_dir[2];
struct ctl_table devices_root_dir[2];
struct ctl_table port_dir[2];
struct ctl_table parport_dir[2];
struct ctl_table dev_dir[2];
};
static const struct parport_device_sysctl_table
parport_device_sysctl_template = {
.sysctl_header = NULL,
{
{
.procname = "timeslice",
.data = NULL,
.maxlen = sizeof(unsigned long),
.mode = 0644,
.proc_handler = proc_doulongvec_ms_jiffies_minmax,
.extra1 = (void*) &parport_min_timeslice_value,
.extra2 = (void*) &parport_max_timeslice_value
},
{}
},
{
{
.procname = NULL,
.data = NULL,
.maxlen = 0,
.mode = 0555,
},
{}
}
};
struct parport_default_sysctl_table
{
struct ctl_table_header *sysctl_header;
struct ctl_table vars[3];
struct ctl_table default_dir[2];
struct ctl_table parport_dir[2];
struct ctl_table dev_dir[2];
};
static struct parport_default_sysctl_table
parport_default_sysctl_table = {
.sysctl_header = NULL,
{
{
.procname = "timeslice",
.data = &parport_default_timeslice,
.maxlen = sizeof(parport_default_timeslice),
.mode = 0644,
.proc_handler = proc_doulongvec_ms_jiffies_minmax,
.extra1 = (void*) &parport_min_timeslice_value,
.extra2 = (void*) &parport_max_timeslice_value
},
{
.procname = "spintime",
.data = &parport_default_spintime,
.maxlen = sizeof(parport_default_spintime),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = (void*) &parport_min_spintime_value,
.extra2 = (void*) &parport_max_spintime_value
},
{}
}
};
int parport_proc_register(struct parport *port)
{
struct parport_sysctl_table *t;
char *tmp_dir_path;
size_t tmp_path_len, port_name_len;
int bytes_written, i, err = 0;
t = kmemdup(&parport_sysctl_template, sizeof(*t), GFP_KERNEL);
if (t == NULL)
return -ENOMEM;
t->device_dir[0].extra1 = port;
t->vars[0].data = &port->spintime;
for (i = 0; i < 5; i++) {
t->vars[i].extra1 = port;
t->vars[5 + i].extra2 = &port->probe_info[i];
}
port_name_len = strnlen(port->name, PARPORT_NAME_MAX_LEN);
/*
* Allocate a buffer for two paths: dev/parport/PORT and dev/parport/PORT/devices.
* We calculate for the second as that will give us enough for the first.
*/
tmp_path_len = PARPORT_BASE_DEVICES_PATH_SIZE + port_name_len;
tmp_dir_path = kzalloc(tmp_path_len, GFP_KERNEL);
if (!tmp_dir_path) {
err = -ENOMEM;
goto exit_free_t;
}
bytes_written = snprintf(tmp_dir_path, tmp_path_len,
"dev/parport/%s/devices", port->name);
if (tmp_path_len <= bytes_written) {
err = -ENOENT;
goto exit_free_tmp_dir_path;
}
t->devices_header = register_sysctl(tmp_dir_path, t->device_dir);
if (t->devices_header == NULL) {
err = -ENOENT;
goto exit_free_tmp_dir_path;
}
tmp_path_len = PARPORT_BASE_PATH_SIZE + port_name_len;
bytes_written = snprintf(tmp_dir_path, tmp_path_len,
"dev/parport/%s", port->name);
if (tmp_path_len <= bytes_written) {
err = -ENOENT;
goto unregister_devices_h;
}
t->port_header = register_sysctl(tmp_dir_path, t->vars);
if (t->port_header == NULL) {
err = -ENOENT;
goto unregister_devices_h;
}
port->sysctl_table = t;
kfree(tmp_dir_path);
return 0;
unregister_devices_h:
unregister_sysctl_table(t->devices_header);
exit_free_tmp_dir_path:
kfree(tmp_dir_path);
exit_free_t:
kfree(t);
return err;
}
int parport_proc_unregister(struct parport *port)
{
if (port->sysctl_table) {
struct parport_sysctl_table *t = port->sysctl_table;
port->sysctl_table = NULL;
unregister_sysctl_table(t->devices_header);
unregister_sysctl_table(t->port_header);
kfree(t);
}
return 0;
}
int parport_device_proc_register(struct pardevice *device)
{
int bytes_written, err = 0;
struct parport_device_sysctl_table *t;
struct parport * port = device->port;
size_t port_name_len, device_name_len, tmp_dir_path_len;
char *tmp_dir_path;
t = kmemdup(&parport_device_sysctl_template, sizeof(*t), GFP_KERNEL);
if (t == NULL)
return -ENOMEM;
port_name_len = strnlen(port->name, PARPORT_NAME_MAX_LEN);
device_name_len = strnlen(device->name, PATH_MAX);
/* Allocate a buffer for two paths: dev/parport/PORT/devices/DEVICE. */
tmp_dir_path_len = PARPORT_BASE_DEVICES_PATH_SIZE + port_name_len + device_name_len;
tmp_dir_path = kzalloc(tmp_dir_path_len, GFP_KERNEL);
if (!tmp_dir_path) {
err = -ENOMEM;
goto exit_free_t;
}
bytes_written = snprintf(tmp_dir_path, tmp_dir_path_len, "dev/parport/%s/devices/%s",
port->name, device->name);
if (tmp_dir_path_len <= bytes_written) {
err = -ENOENT;
goto exit_free_path;
}
t->vars[0].data = &device->timeslice;
t->sysctl_header = register_sysctl(tmp_dir_path, t->vars);
if (t->sysctl_header == NULL) {
kfree(t);
t = NULL;
}
device->sysctl_table = t;
kfree(tmp_dir_path);
return 0;
exit_free_path:
kfree(tmp_dir_path);
exit_free_t:
kfree(t);
return err;
}
int parport_device_proc_unregister(struct pardevice *device)
{
if (device->sysctl_table) {
struct parport_device_sysctl_table *t = device->sysctl_table;
device->sysctl_table = NULL;
unregister_sysctl_table(t->sysctl_header);
kfree(t);
}
return 0;
}
static int __init parport_default_proc_register(void)
{
int ret;
parport_default_sysctl_table.sysctl_header =
register_sysctl("dev/parport/default", parport_default_sysctl_table.vars);
if (!parport_default_sysctl_table.sysctl_header)
return -ENOMEM;
ret = parport_bus_init();
if (ret) {
unregister_sysctl_table(parport_default_sysctl_table.
sysctl_header);
return ret;
}
return 0;
}
static void __exit parport_default_proc_unregister(void)
{
if (parport_default_sysctl_table.sysctl_header) {
unregister_sysctl_table(parport_default_sysctl_table.
sysctl_header);
parport_default_sysctl_table.sysctl_header = NULL;
}
parport_bus_exit();
}
#else /* no sysctl or no procfs*/
int parport_proc_register(struct parport *pp)
{
return 0;
}
int parport_proc_unregister(struct parport *pp)
{
return 0;
}
int parport_device_proc_register(struct pardevice *device)
{
return 0;
}
int parport_device_proc_unregister(struct pardevice *device)
{
return 0;
}
static int __init parport_default_proc_register (void)
{
return parport_bus_init();
}
static void __exit parport_default_proc_unregister (void)
{
parport_bus_exit();
}
#endif
subsys_initcall(parport_default_proc_register)
module_exit(parport_default_proc_unregister)