pdc_stable.c

linux 内核源代码

		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 */
	write_lock(&entry->rw_lock);
	
	/* 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 */
	pdcspath_store(entry);
	write_unlock(&entry->rw_lock);
	
	printk(KERN_INFO PDCS_PREFIX ": 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 (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, 0644, pdcspath_hwpath_read, pdcspath_hwpath_write);
static PATHS_ATTR(layer, 0644, 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,
};


/* For more insight of what's going on here, refer to PDC Procedures doc,
 * Section PDC_STABLE */

/**
 * pdcs_size_read - Stable Storage size output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 */
static ssize_t
pdcs_size_read(struct kset *kset, char *buf)
{
	char *out = buf;

	if (!kset || !buf)
		return -EINVAL;

	/* show the size of the stable storage */
	out += sprintf(out, "%ld\n", pdcs_size);

	return out - buf;
}

/**
 * pdcs_auto_read - Stable Storage autoboot/search flag output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 * @knob: The PF_AUTOBOOT or PF_AUTOSEARCH flag
 */
static ssize_t
pdcs_auto_read(struct kset *kset, char *buf, int knob)
{
	char *out = buf;
	struct pdcspath_entry *pathentry;

	if (!kset || !buf)
		return -EINVAL;

	/* Current flags are stored in primary boot path entry */
	pathentry = &pdcspath_entry_primary;

	read_lock(&pathentry->rw_lock);
	out += sprintf(out, "%s\n", (pathentry->devpath.flags & knob) ?
					"On" : "Off");
	read_unlock(&pathentry->rw_lock);

	return out - buf;
}

/**
 * pdcs_autoboot_read - Stable Storage autoboot flag output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 */
static inline ssize_t
pdcs_autoboot_read(struct kset *kset, char *buf)
{
	return pdcs_auto_read(kset, buf, PF_AUTOBOOT);
}

/**
 * pdcs_autosearch_read - Stable Storage autoboot flag output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 */
static inline ssize_t
pdcs_autosearch_read(struct kset *kset, char *buf)
{
	return pdcs_auto_read(kset, buf, PF_AUTOSEARCH);
}

/**
 * pdcs_timer_read - Stable Storage timer count output (in seconds).
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 *
 * The value of the timer field correponds to a number of seconds in powers of 2.
 */
static ssize_t
pdcs_timer_read(struct kset *kset, char *buf)
{
	char *out = buf;
	struct pdcspath_entry *pathentry;

	if (!kset || !buf)
		return -EINVAL;

	/* Current flags are stored in primary boot path entry */
	pathentry = &pdcspath_entry_primary;

	/* print the timer value in seconds */
	read_lock(&pathentry->rw_lock);
	out += sprintf(out, "%u\n", (pathentry->devpath.flags & PF_TIMER) ?
				(1 << (pathentry->devpath.flags & PF_TIMER)) : 0);
	read_unlock(&pathentry->rw_lock);

	return out - buf;
}

/**
 * pdcs_osid_read - Stable Storage OS ID register output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 */
static ssize_t
pdcs_osid_read(struct kset *kset, char *buf)
{
	char *out = buf;

	if (!kset || !buf)
		return -EINVAL;

	out += sprintf(out, "%s dependent data (0x%.4x)\n",
		os_id_to_string(pdcs_osid), pdcs_osid);

	return out - buf;
}

/**
 * pdcs_osdep1_read - Stable Storage OS-Dependent data area 1 output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 *
 * This can hold 16 bytes of OS-Dependent data.
 */
static ssize_t
pdcs_osdep1_read(struct kset *kset, char *buf)
{
	char *out = buf;
	u32 result[4];

	if (!kset || !buf)
		return -EINVAL;

	if (pdc_stable_read(PDCS_ADDR_OSD1, &result, sizeof(result)) != PDC_OK)
		return -EIO;

	out += sprintf(out, "0x%.8x\n", result[0]);
	out += sprintf(out, "0x%.8x\n", result[1]);
	out += sprintf(out, "0x%.8x\n", result[2]);
	out += sprintf(out, "0x%.8x\n", result[3]);

	return out - buf;
}

/**
 * pdcs_diagnostic_read - Stable Storage Diagnostic register output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 *
 * I have NFC how to interpret the content of that register ;-).
 */
static ssize_t
pdcs_diagnostic_read(struct kset *kset, char *buf)
{
	char *out = buf;
	u32 result;

	if (!kset || !buf)
		return -EINVAL;

	/* get diagnostic */
	if (pdc_stable_read(PDCS_ADDR_DIAG, &result, sizeof(result)) != PDC_OK)
		return -EIO;

	out += sprintf(out, "0x%.4x\n", (result >> 16));

	return out - buf;
}

/**
 * pdcs_fastsize_read - Stable Storage FastSize register output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 *
 * This register holds the amount of system RAM to be tested during boot sequence.
 */
static ssize_t
pdcs_fastsize_read(struct kset *kset, char *buf)
{
	char *out = buf;
	u32 result;

	if (!kset || !buf)
		return -EINVAL;

	/* get fast-size */
	if (pdc_stable_read(PDCS_ADDR_FSIZ, &result, sizeof(result)) != PDC_OK)
		return -EIO;

	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_osdep2_read - Stable Storage OS-Dependent data area 2 output.
 * @kset: An allocated and populated struct kset. We don't use it tho.
 * @buf: The output buffer to write to.
 *
 * This can hold pdcs_size - 224 bytes of OS-Dependent data, when available.
 */
static ssize_t
pdcs_osdep2_read(struct kset *kset, char *buf)
{
	char *out = buf;
	unsigned long size;
	unsigned short i;
	u32 result;

	if (unlikely(pdcs_size <= 224))
		return -ENODATA;

	size = pdcs_size - 224;

	if (!kset || !buf)
		return -EINVAL;