/*
* Interfaces to retrieve and set PDC Stable options (firmware)
*
* Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* DEV NOTE: the PDC Procedures reference states that:
* "A minimum of 96 bytes of Stable Storage is required. Providing more than
* 96 bytes of Stable Storage is optional [...]. Failure to provide the
* optional locations from 96 to 192 results in the loss of certain
* functionality during boot."
*
* Since locations between 96 and 192 are the various paths, most (if not
* all) PA-RISC machines should have them. Anyway, for safety reasons, the
* following code can deal with only 96 bytes of Stable Storage, and all
* sizes between 96 and 192 bytes (provided they are multiple of struct
* device_path size, eg: 128, 160 and 192) to provide full information.
* The code makes no use of data above 192 bytes. One last word: there's one
* path we can always count on: the primary path.
*/
#undef PDCS_DEBUG
#ifdef PDCS_DEBUG
#define DPRINTK(fmt, args...) printk(KERN_DEBUG fmt, ## args)
#else
#define DPRINTK(fmt, args...)
#endif
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/capability.h>
#include <linux/ctype.h>
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <asm/pdc.h>
#include <asm/page.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#define PDCS_VERSION "0.10"
#define PDCS_ADDR_PPRI 0x00
#define PDCS_ADDR_OSID 0x40
#define PDCS_ADDR_FSIZ 0x5C
#define PDCS_ADDR_PCON 0x60
#define PDCS_ADDR_PALT 0x80
#define PDCS_ADDR_PKBD 0xA0
MODULE_AUTHOR("Thibaut VARENE <varenet@parisc-linux.org>");
MODULE_DESCRIPTION("sysfs interface to HP PDC Stable Storage data");
MODULE_LICENSE("GPL");
MODULE_VERSION(PDCS_VERSION);
static unsigned long pdcs_size __read_mostly;
/* This struct defines what we need to deal with a parisc pdc path entry */
struct pdcspath_entry {
short ready; /* entry record is valid if != 0 */
unsigned long addr; /* entry address in stable storage */
char *name; /* entry name */
struct device_path devpath; /* device path in parisc representation */
struct device *dev; /* corresponding device */
struct kobject kobj;
};
struct pdcspath_attribute {
struct attribute attr;
ssize_t (*show)(struct pdcspath_entry *entry, char *buf);
ssize_t (*store)(struct pdcspath_entry *entry, const char *buf, size_t count);
};
#define PDCSPATH_ENTRY(_addr, _name) \
struct pdcspath_entry pdcspath_entry_##_name = { \
.ready = 0, \
.addr = _addr, \
.name = __stringify(_name), \
};
#define PDCS_ATTR(_name, _mode, _show, _store) \
struct subsys_attribute pdcs_attr_##_name = { \
.attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
.show = _show, \
.store = _store, \
};
#define PATHS_ATTR(_name, _mode, _show, _store) \
struct pdcspath_attribute paths_attr_##_name = { \
.attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE}, \
.show = _show, \
.store = _store, \
};
#define to_pdcspath_attribute(_attr) container_of(_attr, struct pdcspath_attribute, attr)
#define to_pdcspath_entry(obj) container_of(obj, struct pdcspath_entry, kobj)
/**
* pdcspath_fetch - This function populates the path entry structs.
* @entry: A pointer to an allocated pdcspath_entry.
*
* The general idea is that you don't read from the Stable Storage every time
* you access the files provided by the facilites. We store a copy of the
* content of the stable storage WRT various paths in these structs. We read
* these structs when reading the files, and we will write to these structs when
* writing to the files, and only then write them back to the Stable Storage.
*/
static int
pdcspath_fetch(struct pdcspath_entry *entry)
{
struct device_path *devpath;
if (!entry)
return -EINVAL;
devpath = &entry->devpath;
DPRINTK("%s: fetch: 0x%p, 0x%p, addr: 0x%lx\n", __func__,
entry, devpath, entry->addr);
/* addr, devpath and count must be word aligned */
if (pdc_stable_read(entry->addr, devpath, sizeof(*devpath)) != PDC_OK)
return -EIO;
/* Find the matching device.
NOTE: hardware_path overlays with device_path, so the nice cast can
be used */
entry->dev = hwpath_to_device((struct hardware_path *)devpath);
entry->ready = 1;
DPRINTK("%s: device: 0x%p\n", __func__, entry->dev);
return 0;
}
/**
* pdcspath_store - This function writes a path to stable storage.
* @entry: A pointer to an allocated pdcspath_entry.
*
* It can be used in two ways: either by passing it a preset devpath struct
* containing an already computed hardware path, or by passing it a device
* pointer, from which it'll find out the corresponding hardware path.
* For now we do not handle the case where there's an error in writing to the
* Stable Storage area, so you'd better not mess up the data :P
*/
static int
pdcspath_store(struct pdcspath_entry *entry)
{
struct device_path *devpath;
if (!entry)
return -EINVAL;
devpath = &entry->devpath;
/* We expect the caller to set the ready flag to 0 if the hardware
path struct provided is invalid, so that we know we have to fill it.
First case, we don't have a preset hwpath... */
if (!entry->ready) {
/* ...but we have a device, map it */
if (entry->dev)
device_to_hwpath(entry->dev, (struct hardware_path *)devpath);
else
return -EINVAL;
}
/* else, we expect the provided hwpath to be valid. */
DPRINTK("%s: store: 0x%p, 0x%p, addr: 0x%lx\n", __func__,
entry, devpath, entry->addr);
/* addr, devpath and count must be word aligned */
if (pdc_stable_write(entry->addr, devpath, sizeof(*devpath)) != PDC_OK) {
printk(KERN_ERR "%s: an error occured when writing to PDC.\n"
"It is likely that the Stable Storage data has been corrupted.\n"
"Please check it carefully upon next reboot.\n", __func__);
return -EIO;
}
/* kobject is already registered */
entry->ready = 2;
DPRINTK("%s: device: 0x%p\n", __func__, entry->dev);
return 0;
}
/**
* pdcspath_hwpath_read - This function handles hardware path pretty printing.
* @entry: An allocated and populated pdscpath_entry struct.
* @buf: The output buffer to write to.
*
* We will call this function to format the output of the hwpath attribute file.
*/
static ssize_t
pdcspath_hwpath_read(struct pdcspath_entry *entry, char *buf)
{
char *out = buf;
struct device_path *devpath;
unsigned short i;
if (!entry || !buf)
return -EINVAL;
devpath = &entry->devpath;
if (!entry->ready)
return -ENODATA;
for (i = 0; i < 6; i++) {
if (devpath->bc[i] >= 128)
continue;
out += sprintf(out, "%u/", (unsigned char)devpath->bc[i]);
}
out += sprintf(out, "%u\n", (unsigned char)devpath->mod);
return out - buf;
}
/**
* pdcspath_hwpath_write - This function handles hardware path modifying.
* @entry: An allocated and populated pdscpath_entry struct.
* @buf: The input buffer to read from.
* @count: The number of bytes to be read.
*
* We will call this function to change the current hardware path.
* Hardware paths are to be given '/'-delimited, without brackets.
* We take care to make sure that the provided path actually maps to an existing
* device, BUT nothing would prevent some foolish user to set the path to some
* PCI bridge or even a CPU...
* A better work around would be to make sure we are at the end of a device tree
* for instance, but it would be IMHO beyond the simple scope of that driver.
* The aim is to provide a facility. Data correctness is left to userland.
*/
static ssize_t
pdcspath_hwpath_write(struct pdcspath_entry *entry, const char *buf, size_t count)
{
struct hardware_path hwpath;
unsigned short i;
char in[count+1], *temp;
struct device *dev;
if (!entry || !buf || !count)
return -EINVAL;
/* We'll use a local copy of buf */
memset(in, 0, count+1);
strncpy(in, buf, count);
/* Let's clean up the target. 0xff is a blank pattern */
memset(&hwpath, 0xff, sizeof(hwpath));
/* First, pick the mod field (the last one of the input string) */
if (!(temp = strrchr(in, '/')))
return -EINVAL;
hwpath.mod = simple_strtoul(temp+1, NULL, 10);
in[temp-in] = '\0'; /* truncate the remaining string. just precaution */
DPRINTK("%s: mod: %d\n", __func__, hwpath.mod);
/* Then, loop for each delimiter, making sure we don't have too many.
we write the bc fields in a down-top way. No matter what, we stop
before writing the last field. If there are too many fields anyway,
then the user is a moron and it'll be caught up later when we'll
check the consistency of the given hwpath. */
for (i=5; ((temp = strrchr(in, '/'))) && (temp-in > 0) && (likely(i)); i--) {
hwpath.bc[i] = simple_strtoul(temp+1, NULL, 10);
in[temp-in] = '\0';
DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]);
}
/* Store the final field */
hwpath.bc[i] = simple_strtoul(in, NULL, 10);
DPRINTK("%s: bc[%d]: %d\n", __func__, i, hwpath.bc[i]);
/* Now we check that the user isn't trying to lure us */
if (!(dev = hwpath_to_device((struct hardware_path *)&hwpath))) {
printk(KERN_WARNING "%s: attempt to set invalid \"%s\" "
"hardware path: %s\n", __func__, entry->name, buf);
return -EINVAL;
}
/* So far so good, let's get in deep */
entry->ready = 0;
entry->dev = dev;
/* Now, dive in. Write back to the hardware */
WARN_ON(pdcspath_store(entry)); /* this warn should *NEVER* happen */
/* Update the symlink to the real device */
sysfs_remove_link(&entry->kobj, "device");
sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device");
printk(KERN_INFO "PDC Stable Storage: changed \"%s\" path to \"%s\"\n",
entry->name, buf);
return count;
}
/**
* pdcspath_layer_read - Extended layer (eg. SCSI ids) pretty printing.
* @entry: An allocated and populated pdscpath_entry struct.
* @buf: The output buffer to write to.
*
* We will call this function to format the output of the layer attribute file.
*/
static ssize_t
pdcspath_layer_read(struct pdcspath_entry *entry, char *buf)
{
char *out = buf;
struct device_path *devpath;
unsigned short i;
if (!entry || !buf)
return -EINVAL;
devpath = &entry->devpath;
if (!entry->ready)
return -ENODATA;
for (i = 0; devpath->layers[i] && (likely(i < 6)); i++)
out += sprintf(out, "%u ", devpath->layers[i]);
out += sprintf(out, "\n");
return out - buf;
}
/**
* pdcspath_layer_write - This function handles extended layer modifying.
* @entry: An allocated and populated pdscpath_entry struct.
* @buf: The input buffer to read from.
* @count: The number of bytes to be read.
*
* We will call this function to change the current layer value.
* Layers are to be given '.'-delimited, without brackets.
* XXX beware we are far less checky WRT input data provided than for hwpath.
* Potential harm can be done, since there's no way to check the validity of
* the layer fields.
*/
static ssize_t
pdcspath_layer_write(struct pdcspath_entry *entry, const char *buf, size_t count)
{
unsigned int layers[6]; /* device-specific info (ctlr#, unit#, ...) */
unsigned short i;
char in[count+1], *temp;
if (!entry || !buf || !count)
return -EINVAL;
/* We'll use a local copy of buf */
memset(in, 0, count+1);
strncpy(in, buf, count);
/* Let's clean up the target. 0 is a blank pattern */
memset(&layers, 0, sizeof(layers));
/* First, pick the first layer */
if (unlikely(!isdigit(*in)))
return -EINVAL;
layers[0] = simple_strtoul(in, NULL, 10);
DPRINTK("%s: layer[0]: %d\n", __func__, layers[0]);
temp = in;
for (i=1; ((temp = strchr(temp, '.'))) && (likely(i<6)); i++) {
if (unlikely(!isdigit(*(++temp))))
return -EINVAL;
layers[i] = simple_strtoul(temp, NULL, 10);
DPRINTK("%s: layer[%d]: %d\n", __func__, i, layers[i]);
}
/* So far so good, let's get in deep */
/* First, overwrite the current layers with the new ones, not touching
the hardware path. */
memcpy(&entry->devpath.layers, &layers, sizeof(layers));
/* Now, dive in. Write back to the hardware */
WARN_ON(pdcspath_store(entry)); /* this warn should *NEVER* happen */
printk(KERN_INFO "PDC Stable Storage: changed \"%s\" layers to \"%s\"\n",
entry->name, buf);
return count;
}
/**
* pdcspath_attr_show - Generic read function call wrapper.
* @kobj: The kobject to get info from.
* @attr: The attribute looked upon.
* @buf: The output buffer.
*/
static ssize_t
pdcspath_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
{
struct pdcspath_entry *entry = to_pdcspath_entry(kobj);
struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr);
ssize_t ret = 0;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (pdcs_attr->show)
ret = pdcs_attr->show(entry, buf);
return ret;
}
/**
* pdcspath_attr_store - Generic write function call wrapper.
* @kobj: The kobject to write info to.
* @attr: The attribute to be modified.
* @buf: The input buffer.
* @count: The size of the buffer.
*/
static ssize_t
pdcspath_attr_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t count)
{
struct pdcspath_entry *entry = to_pdcspath_entry(kobj);
struct pdcspath_attribute *pdcs_attr = to_pdcspath_attribute(attr);
ssize_t ret = 0;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (pdcs_attr->store)
ret = pdcs_attr->store(entry, buf, count);
return ret;
}
static struct sysfs_ops pdcspath_attr_ops = {
.show = pdcspath_attr_show,
.store = pdcspath_attr_store,
};
/* These are the two attributes of any PDC path. */
static PATHS_ATTR(hwpath, 0600, pdcspath_hwpath_read, pdcspath_hwpath_write);
static PATHS_ATTR(layer, 0600, pdcspath_layer_read, pdcspath_layer_write);
static struct attribute *paths_subsys_attrs[] = {
&paths_attr_hwpath.attr,
&paths_attr_layer.attr,
NULL,
};
/* Specific kobject type for our PDC paths */
static struct kobj_type ktype_pdcspath = {
.sysfs_ops = &pdcspath_attr_ops,
.default_attrs = paths_subsys_attrs,
};
/* We hard define the 4 types of path we expect to find */
static PDCSPATH_ENTRY(PDCS_ADDR_PPRI, primary);
static PDCSPATH_ENTRY(PDCS_ADDR_PCON, console);
static PDCSPATH_ENTRY(PDCS_ADDR_PALT, alternative);
static PDCSPATH_ENTRY(PDCS_ADDR_PKBD, keyboard);
/* An array containing all PDC paths we will deal with */
static struct pdcspath_entry *pdcspath_entries[] = {
&pdcspath_entry_primary,
&pdcspath_entry_alternative,
&pdcspath_entry_console,
&pdcspath_entry_keyboard,
NULL,
};
/**
* pdcs_info_read - Pretty printing of the remaining useful data.
* @entry: An allocated and populated subsytem struct. We don't use it tho.
* @buf: The output buffer to write to.
*
* We will call this function to format the output of the 'info' attribute file.
* Please refer to PDC Procedures documentation, section PDC_STABLE to get a
* better insight of what we're doing here.
*/
static ssize_t
pdcs_info_read(struct subsystem *entry, char *buf)
{
char *out = buf;
__u32 result;
struct device_path devpath;
char *tmpstr = NULL;
if (!entry || !buf)
return -EINVAL;
/* show the size of the stable storage */
out += sprintf(out, "Stable Storage size: %ld bytes\n", pdcs_size);
/* deal with flags */
if (pdc_stable_read(PDCS_ADDR_PPRI, &devpath, sizeof(devpath)) != PDC_OK)
return -EIO;
out += sprintf(out, "Autoboot: %s\n", (devpath.flags & PF_AUTOBOOT) ? "On" : "Off");
out += sprintf(out, "Autosearch: %s\n", (devpath.flags & PF_AUTOSEARCH) ? "On" : "Off");
out += sprintf(out, "Timer: %u s\n", (devpath.flags & PF_TIMER) ? (1 << (devpath.flags & PF_TIMER)) : 0);
/* get OSID */
if (pdc_stable_read(PDCS_ADDR_OSID, &result, sizeof(result)) != PDC_OK)
return -EIO;
/* the actual result is 16 bits away */
switch (result >> 16) {
case 0x0000: tmpstr = "No OS-dependent data"; break;
case 0x0001: tmpstr = "HP-UX dependent data"; break;
case 0x0002: tmpstr = "MPE-iX dependent data"; break;
case 0x0003: tmpstr = "OSF dependent data"; break;
case 0x0004: tmpstr = "HP-RT dependent data"; break;
case 0x0005: tmpstr = "Novell Netware dependent data"; break;
default: tmpstr = "Unknown"; break;
}
out += sprintf(out, "OS ID: %s (0x%.4x)\n", tmpstr, (result >> 16));
/* get fast-size */
if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK)
return -EIO;
out += sprintf(out, "Memory tested: ");
if ((result & 0x0F) < 0x0E)
out += sprintf(out, "%d kB", (1<<(result & 0x0F))*256);
else
out += sprintf(out, "All");
out += sprintf(out, "\n");
return out - buf;
}
/**
* pdcs_info_write - This function handles boot flag modifying.
* @entry: An allocated and populated subsytem struct. We don't use it tho.
* @buf: The input buffer to read from.
* @count: The number of bytes to be read.
*
* We will call this function to change the current boot flags.
* We expect a precise syntax:
* \"n n\" (n == 0 or 1) to toggle respectively AutoBoot and AutoSearch
*
* As of now there is no incentive on my side to provide more "knobs" to that
* interface, since modifying the rest of the data is pretty meaningless when
* the machine is running and for the expected use of that facility, such as
* PALO setting up the boot disk when installing a Linux distribution...
*/
static ssize_t
pdcs_info_write(struct subsystem *entry, const char *buf, size_t count)
{
struct pdcspath_entry *pathentry;
unsigned char flags;
char in[count+1], *temp;
char c;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (!entry || !buf || !count)
return -EINVAL;
/* We'll use a local copy of buf */
memset(in, 0, count+1);
strncpy(in, buf, count);
/* Current flags are stored in primary boot path entry */
pathentry = &pdcspath_entry_primary;
/* Be nice to the existing flag record */
flags = pathentry->devpath.flags;
DPRINTK("%s: flags before: 0x%X\n", __func__, flags);
temp = in;
while (*temp && isspace(*temp))
temp++;
c = *temp++ - '0';
if ((c != 0) && (c != 1))
goto parse_error;
if (c == 0)
flags &= ~PF_AUTOBOOT;
else
flags |= PF_AUTOBOOT;
if (*temp++ != ' ')
goto parse_error;
c = *temp++ - '0';
if ((c != 0) && (c != 1))
goto parse_error;
if (c == 0)
flags &= ~PF_AUTOSEARCH;
else
flags |= PF_AUTOSEARCH;
DPRINTK("%s: flags after: 0x%X\n", __func__, flags);
/* So far so good, let's get in deep */
/* Change the path entry flags first */
pathentry->devpath.flags = flags;
/* Now, dive in. Write back to the hardware */
WARN_ON(pdcspath_store(pathentry)); /* this warn should *NEVER* happen */
printk(KERN_INFO "PDC Stable Storage: changed flags to \"%s\"\n", buf);
return count;
parse_error:
printk(KERN_WARNING "%s: Parse error: expect \"n n\" (n == 0 or 1) for AB and AS\n", __func__);
return -EINVAL;
}
/* The last attribute (the 'root' one actually) with all remaining data. */
static PDCS_ATTR(info, 0600, pdcs_info_read, pdcs_info_write);
static struct subsys_attribute *pdcs_subsys_attrs[] = {
&pdcs_attr_info,
NULL, /* maybe more in the future? */
};
static decl_subsys(paths, &ktype_pdcspath, NULL);
static decl_subsys(pdc, NULL, NULL);
/**
* pdcs_register_pathentries - Prepares path entries kobjects for sysfs usage.
*
* It creates kobjects corresponding to each path entry with nice sysfs
* links to the real device. This is where the magic takes place: when
* registering the subsystem attributes during module init, each kobject hereby
* created will show in the sysfs tree as a folder containing files as defined
* by path_subsys_attr[].
*/
static inline int __init
pdcs_register_pathentries(void)
{
unsigned short i;
struct pdcspath_entry *entry;
int err;
for (i = 0; (entry = pdcspath_entries[i]); i++) {
if (pdcspath_fetch(entry) < 0)
continue;
if ((err = kobject_set_name(&entry->kobj, "%s", entry->name)))
return err;
kobj_set_kset_s(entry, paths_subsys);
if ((err = kobject_register(&entry->kobj)))
return err;
/* kobject is now registered */
entry->ready = 2;
if (!entry->dev)
continue;
/* Add a nice symlink to the real device */
sysfs_create_link(&entry->kobj, &entry->dev->kobj, "device");
}
return 0;
}
/**
* pdcs_unregister_pathentries - Routine called when unregistering the module.
*/
static inline void
pdcs_unregister_pathentries(void)
{
unsigned short i;
struct pdcspath_entry *entry;
for (i = 0; (entry = pdcspath_entries[i]); i++)
if (entry->ready >= 2)
kobject_unregister(&entry->kobj);
}
/*
* For now we register the pdc subsystem with the firmware subsystem
* and the paths subsystem with the pdc subsystem
*/
static int __init
pdc_stable_init(void)
{
struct subsys_attribute *attr;
int i, rc = 0, error = 0;
/* find the size of the stable storage */
if (pdc_stable_get_size(&pdcs_size) != PDC_OK)
return -ENODEV;
printk(KERN_INFO "PDC Stable Storage facility v%s\n", PDCS_VERSION);
/* For now we'll register the pdc subsys within this driver */
if ((rc = firmware_register(&pdc_subsys)))
goto fail_firmreg;
/* Don't forget the info entry */
for (i = 0; (attr = pdcs_subsys_attrs[i]) && !error; i++)
if (attr->show)
error = subsys_create_file(&pdc_subsys, attr);
/* register the paths subsys as a subsystem of pdc subsys */
kset_set_kset_s(&paths_subsys, pdc_subsys);
if ((rc= subsystem_register(&paths_subsys)))
goto fail_subsysreg;
/* now we create all "files" for the paths subsys */
if ((rc = pdcs_register_pathentries()))
goto fail_pdcsreg;
return rc;
fail_pdcsreg:
pdcs_unregister_pathentries();
subsystem_unregister(&paths_subsys);
fail_subsysreg:
firmware_unregister(&pdc_subsys);
fail_firmreg:
printk(KERN_INFO "PDC Stable Storage bailing out\n");
return rc;
}
static void __exit
pdc_stable_exit(void)
{
pdcs_unregister_pathentries();
subsystem_unregister(&paths_subsys);
firmware_unregister(&pdc_subsys);
}
module_init(pdc_stable_init);
module_exit(pdc_stable_exit);
