salinfo.c

linux 内核源代码

	.open  = salinfo_event_open,
	.read  = salinfo_event_read,
};

static int
salinfo_log_open(struct inode *inode, struct file *file)
{
	struct proc_dir_entry *entry = PDE(inode);
	struct salinfo_data *data = entry->data;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;

	spin_lock(&data_lock);
	if (data->open) {
		spin_unlock(&data_lock);
		return -EBUSY;
	}
	data->open = 1;
	spin_unlock(&data_lock);

	if (data->state == STATE_NO_DATA &&
	    !(data->log_buffer = vmalloc(ia64_sal_get_state_info_size(data->type)))) {
		data->open = 0;
		return -ENOMEM;
	}

	return 0;
}

static int
salinfo_log_release(struct inode *inode, struct file *file)
{
	struct proc_dir_entry *entry = PDE(inode);
	struct salinfo_data *data = entry->data;

	if (data->state == STATE_NO_DATA) {
		vfree(data->log_buffer);
		vfree(data->oemdata);
		data->log_buffer = NULL;
		data->oemdata = NULL;
	}
	spin_lock(&data_lock);
	data->open = 0;
	spin_unlock(&data_lock);
	return 0;
}

static void
call_on_cpu(int cpu, void (*fn)(void *), void *arg)
{
	cpumask_t save_cpus_allowed = current->cpus_allowed;
	cpumask_t new_cpus_allowed = cpumask_of_cpu(cpu);
	set_cpus_allowed(current, new_cpus_allowed);
	(*fn)(arg);
	set_cpus_allowed(current, save_cpus_allowed);
}

static void
salinfo_log_read_cpu(void *context)
{
	struct salinfo_data *data = context;
	sal_log_record_header_t *rh;
	data->log_size = ia64_sal_get_state_info(data->type, (u64 *) data->log_buffer);
	rh = (sal_log_record_header_t *)(data->log_buffer);
	/* Clear corrected errors as they are read from SAL */
	if (rh->severity == sal_log_severity_corrected)
		ia64_sal_clear_state_info(data->type);
}

static void
salinfo_log_new_read(int cpu, struct salinfo_data *data)
{
	struct salinfo_data_saved *data_saved;
	unsigned long flags;
	int i;
	int saved_size = ARRAY_SIZE(data->data_saved);

	data->saved_num = 0;
	spin_lock_irqsave(&data_saved_lock, flags);
retry:
	for (i = 0, data_saved = data->data_saved; i < saved_size; ++i, ++data_saved) {
		if (data_saved->buffer && data_saved->cpu == cpu) {
			sal_log_record_header_t *rh = (sal_log_record_header_t *)(data_saved->buffer);
			data->log_size = data_saved->size;
			memcpy(data->log_buffer, rh, data->log_size);
			barrier();	/* id check must not be moved */
			if (rh->id == data_saved->id) {
				data->saved_num = i+1;
				break;
			}
			/* saved record changed by mca.c since interrupt, discard it */
			shift1_data_saved(data, i);
			goto retry;
		}
	}
	spin_unlock_irqrestore(&data_saved_lock, flags);

	if (!data->saved_num)
		call_on_cpu(cpu, salinfo_log_read_cpu, data);
	if (!data->log_size) {
		data->state = STATE_NO_DATA;
		cpu_clear(cpu, data->cpu_event);
	} else {
		data->state = STATE_LOG_RECORD;
	}
}

static ssize_t
salinfo_log_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct proc_dir_entry *entry = PDE(inode);
	struct salinfo_data *data = entry->data;
	u8 *buf;
	u64 bufsize;

	if (data->state == STATE_LOG_RECORD) {
		buf = data->log_buffer;
		bufsize = data->log_size;
	} else if (data->state == STATE_OEMDATA) {
		buf = data->oemdata;
		bufsize = data->oemdata_size;
	} else {
		buf = NULL;
		bufsize = 0;
	}
	return simple_read_from_buffer(buffer, count, ppos, buf, bufsize);
}

static void
salinfo_log_clear_cpu(void *context)
{
	struct salinfo_data *data = context;
	ia64_sal_clear_state_info(data->type);
}

static int
salinfo_log_clear(struct salinfo_data *data, int cpu)
{
	sal_log_record_header_t *rh;
	unsigned long flags;
	spin_lock_irqsave(&data_saved_lock, flags);
	data->state = STATE_NO_DATA;
	if (!cpu_isset(cpu, data->cpu_event)) {
		spin_unlock_irqrestore(&data_saved_lock, flags);
		return 0;
	}
	cpu_clear(cpu, data->cpu_event);
	if (data->saved_num) {
		shift1_data_saved(data, data->saved_num - 1);
		data->saved_num = 0;
	}
	spin_unlock_irqrestore(&data_saved_lock, flags);
	rh = (sal_log_record_header_t *)(data->log_buffer);
	/* Corrected errors have already been cleared from SAL */
	if (rh->severity != sal_log_severity_corrected)
		call_on_cpu(cpu, salinfo_log_clear_cpu, data);
	/* clearing a record may make a new record visible */
	salinfo_log_new_read(cpu, data);
	if (data->state == STATE_LOG_RECORD) {
		spin_lock_irqsave(&data_saved_lock, flags);
		cpu_set(cpu, data->cpu_event);
		salinfo_work_to_do(data);
		spin_unlock_irqrestore(&data_saved_lock, flags);
	}
	return 0;
}

static ssize_t
salinfo_log_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
	struct inode *inode = file->f_path.dentry->d_inode;
	struct proc_dir_entry *entry = PDE(inode);
	struct salinfo_data *data = entry->data;
	char cmd[32];
	size_t size;
	u32 offset;
	int cpu;

	size = sizeof(cmd);
	if (count < size)
		size = count;
	if (copy_from_user(cmd, buffer, size))
		return -EFAULT;

	if (sscanf(cmd, "read %d", &cpu) == 1) {
		salinfo_log_new_read(cpu, data);
	} else if (sscanf(cmd, "clear %d", &cpu) == 1) {
		int ret;
		if ((ret = salinfo_log_clear(data, cpu)))
			count = ret;
	} else if (sscanf(cmd, "oemdata %d %d", &cpu, &offset) == 2) {
		if (data->state != STATE_LOG_RECORD && data->state != STATE_OEMDATA)
			return -EINVAL;
		if (offset > data->log_size - sizeof(efi_guid_t))
			return -EINVAL;
		data->state = STATE_OEMDATA;
		if (salinfo_platform_oemdata) {
			struct salinfo_platform_oemdata_parms parms = {
				.efi_guid = data->log_buffer + offset,
				.oemdata = &data->oemdata,
				.oemdata_size = &data->oemdata_size
			};
			call_on_cpu(cpu, salinfo_platform_oemdata_cpu, &parms);
			if (parms.ret)
				count = parms.ret;
		} else
			data->oemdata_size = 0;
	} else
		return -EINVAL;

	return count;
}

static const struct file_operations salinfo_data_fops = {
	.open    = salinfo_log_open,
	.release = salinfo_log_release,
	.read    = salinfo_log_read,
	.write   = salinfo_log_write,
};

static int __cpuinit
salinfo_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
{
	unsigned int i, cpu = (unsigned long)hcpu;
	unsigned long flags;
	struct salinfo_data *data;
	switch (action) {
	case CPU_ONLINE:
	case CPU_ONLINE_FROZEN:
		spin_lock_irqsave(&data_saved_lock, flags);
		for (i = 0, data = salinfo_data;
		     i < ARRAY_SIZE(salinfo_data);
		     ++i, ++data) {
			cpu_set(cpu, data->cpu_event);
			salinfo_work_to_do(data);
		}
		spin_unlock_irqrestore(&data_saved_lock, flags);
		break;
	case CPU_DEAD:
	case CPU_DEAD_FROZEN:
		spin_lock_irqsave(&data_saved_lock, flags);
		for (i = 0, data = salinfo_data;
		     i < ARRAY_SIZE(salinfo_data);
		     ++i, ++data) {
			struct salinfo_data_saved *data_saved;
			int j;
			for (j = ARRAY_SIZE(data->data_saved) - 1, data_saved = data->data_saved + j;
			     j >= 0;
			     --j, --data_saved) {
				if (data_saved->buffer && data_saved->cpu == cpu) {
					shift1_data_saved(data, j);
				}
			}
			cpu_clear(cpu, data->cpu_event);
		}
		spin_unlock_irqrestore(&data_saved_lock, flags);
		break;
	}
	return NOTIFY_OK;
}

static struct notifier_block salinfo_cpu_notifier __cpuinitdata =
{
	.notifier_call = salinfo_cpu_callback,
	.priority = 0,
};

static int __init
salinfo_init(void)
{
	struct proc_dir_entry *salinfo_dir; /* /proc/sal dir entry */
	struct proc_dir_entry **sdir = salinfo_proc_entries; /* keeps track of every entry */
	struct proc_dir_entry *dir, *entry;
	struct salinfo_data *data;
	int i, j;

	salinfo_dir = proc_mkdir("sal", NULL);
	if (!salinfo_dir)
		return 0;

	for (i=0; i < NR_SALINFO_ENTRIES; i++) {
		/* pass the feature bit in question as misc data */
		*sdir++ = create_proc_read_entry (salinfo_entries[i].name, 0, salinfo_dir,
						  salinfo_read, (void *)salinfo_entries[i].feature);
	}

	for (i = 0; i < ARRAY_SIZE(salinfo_log_name); i++) {
		data = salinfo_data + i;
		data->type = i;
		init_MUTEX(&data->mutex);
		dir = proc_mkdir(salinfo_log_name[i], salinfo_dir);
		if (!dir)
			continue;

		entry = create_proc_entry("event", S_IRUSR, dir);
		if (!entry)
			continue;
		entry->data = data;
		entry->proc_fops = &salinfo_event_fops;
		*sdir++ = entry;

		entry = create_proc_entry("data", S_IRUSR | S_IWUSR, dir);
		if (!entry)
			continue;
		entry->data = data;
		entry->proc_fops = &salinfo_data_fops;
		*sdir++ = entry;

		/* we missed any events before now */
		for_each_online_cpu(j)
			cpu_set(j, data->cpu_event);

		*sdir++ = dir;
	}

	*sdir++ = salinfo_dir;

	init_timer(&salinfo_timer);
	salinfo_timer.expires = jiffies + SALINFO_TIMER_DELAY;
	salinfo_timer.function = &salinfo_timeout;
	add_timer(&salinfo_timer);

	register_hotcpu_notifier(&salinfo_cpu_notifier);

	return 0;
}

/*
 * 'data' contains an integer that corresponds to the feature we're
 * testing
 */
static int
salinfo_read(char *page, char **start, off_t off, int count, int *eof, void *data)
{
	int len = 0;

	len = sprintf(page, (sal_platform_features & (unsigned long)data) ? "1\n" : "0\n");

	if (len <= off+count) *eof = 1;

	*start = page + off;
	len   -= off;

	if (len>count) len = count;
	if (len<0) len = 0;

	return len;
}

module_init(salinfo_init);