/*
 *  Copyright IBM Corp. 2001, 2009
 *  Author(s): Ulrich Weigand <Ulrich.Weigand@de.ibm.com>,
 *	       Martin Schwidefsky <schwidefsky@de.ibm.com>,
 */

#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <asm/ebcdic.h>
#include <asm/debug.h>
#include <asm/sysinfo.h>
#include <asm/cpcmd.h>
#include <asm/topology.h>
#include <asm/fpu/api.h>

int topology_max_mnest;

static inline int __stsi(void *sysinfo, int fc, int sel1, int sel2, int *lvl)
{
	register int r0 asm("0") = (fc << 28) | sel1;
	register int r1 asm("1") = sel2;
	int rc = 0;

	asm volatile(
		"	stsi	0(%3)\n"
		"0:	jz	2f\n"
		"1:	lhi	%1,%4\n"
		"2:\n"
		EX_TABLE(0b, 1b)
		: "+d" (r0), "+d" (rc)
		: "d" (r1), "a" (sysinfo), "K" (-EOPNOTSUPP)
		: "cc", "memory");
	*lvl = ((unsigned int) r0) >> 28;
	return rc;
}

/*
 * stsi - store system information
 *
 * Returns the current configuration level if function code 0 was specified.
 * Otherwise returns 0 on success or a negative value on error.
 */
int stsi(void *sysinfo, int fc, int sel1, int sel2)
{
	int lvl, rc;

	rc = __stsi(sysinfo, fc, sel1, sel2, &lvl);
	if (rc)
		return rc;
	return fc ? 0 : lvl;
}
EXPORT_SYMBOL(stsi);

static bool convert_ext_name(unsigned char encoding, char *name, size_t len)
{
	switch (encoding) {
	case 1: /* EBCDIC */
		EBCASC(name, len);
		break;
	case 2:	/* UTF-8 */
		break;
	default:
		return false;
	}
	return true;
}

static void stsi_1_1_1(struct seq_file *m, struct sysinfo_1_1_1 *info)
{
	int i;

	if (stsi(info, 1, 1, 1))
		return;
	EBCASC(info->manufacturer, sizeof(info->manufacturer));
	EBCASC(info->type, sizeof(info->type));
	EBCASC(info->model, sizeof(info->model));
	EBCASC(info->sequence, sizeof(info->sequence));
	EBCASC(info->plant, sizeof(info->plant));
	EBCASC(info->model_capacity, sizeof(info->model_capacity));
	EBCASC(info->model_perm_cap, sizeof(info->model_perm_cap));
	EBCASC(info->model_temp_cap, sizeof(info->model_temp_cap));
	seq_printf(m, "Manufacturer:         %-16.16s\n", info->manufacturer);
	seq_printf(m, "Type:                 %-4.4s\n", info->type);
	/*
	 * Sigh: the model field has been renamed with System z9
	 * to model_capacity and a new model field has been added
	 * after the plant field. To avoid confusing older programs
	 * the "Model:" prints "model_capacity model" or just
	 * "model_capacity" if the model string is empty .
	 */
	seq_printf(m, "Model:                %-16.16s", info->model_capacity);
	if (info->model[0] != '\0')
		seq_printf(m, " %-16.16s", info->model);
	seq_putc(m, '\n');
	seq_printf(m, "Sequence Code:        %-16.16s\n", info->sequence);
	seq_printf(m, "Plant:                %-4.4s\n", info->plant);
	seq_printf(m, "Model Capacity:       %-16.16s %08u\n",
		   info->model_capacity, info->model_cap_rating);
	if (info->model_perm_cap_rating)
		seq_printf(m, "Model Perm. Capacity: %-16.16s %08u\n",
			   info->model_perm_cap,
			   info->model_perm_cap_rating);
	if (info->model_temp_cap_rating)
		seq_printf(m, "Model Temp. Capacity: %-16.16s %08u\n",
			   info->model_temp_cap,
			   info->model_temp_cap_rating);
	if (info->ncr)
		seq_printf(m, "Nominal Cap. Rating:  %08u\n", info->ncr);
	if (info->npr)
		seq_printf(m, "Nominal Perm. Rating: %08u\n", info->npr);
	if (info->ntr)
		seq_printf(m, "Nominal Temp. Rating: %08u\n", info->ntr);
	if (info->cai) {
		seq_printf(m, "Capacity Adj. Ind.:   %d\n", info->cai);
		seq_printf(m, "Capacity Ch. Reason:  %d\n", info->ccr);
		seq_printf(m, "Capacity Transient:   %d\n", info->t);
	}
	if (info->p) {
		for (i = 1; i <= ARRAY_SIZE(info->typepct); i++) {
			seq_printf(m, "Type %d Percentage:    %d\n",
				   i, info->typepct[i - 1]);
		}
	}
}

static void stsi_15_1_x(struct seq_file *m, struct sysinfo_15_1_x *info)
{
	int i;

	seq_putc(m, '\n');
	if (!MACHINE_HAS_TOPOLOGY)
		return;
	if (stsi(info, 15, 1, topology_max_mnest))
		return;
	seq_printf(m, "CPU Topology HW:     ");
	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
		seq_printf(m, " %d", info->mag[i]);
	seq_putc(m, '\n');
#ifdef CONFIG_SCHED_TOPOLOGY
	store_topology(info);
	seq_printf(m, "CPU Topology SW:     ");
	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
		seq_printf(m, " %d", info->mag[i]);
	seq_putc(m, '\n');
#endif
}

static void stsi_1_2_2(struct seq_file *m, struct sysinfo_1_2_2 *info)
{
	struct sysinfo_1_2_2_extension *ext;
	int i;

	if (stsi(info, 1, 2, 2))
		return;
	ext = (struct sysinfo_1_2_2_extension *)
		((unsigned long) info + info->acc_offset);
	seq_printf(m, "CPUs Total:           %d\n", info->cpus_total);
	seq_printf(m, "CPUs Configured:      %d\n", info->cpus_configured);
	seq_printf(m, "CPUs Standby:         %d\n", info->cpus_standby);
	seq_printf(m, "CPUs Reserved:        %d\n", info->cpus_reserved);
	if (info->mt_installed) {
		seq_printf(m, "CPUs G-MTID:          %d\n", info->mt_gtid);
		seq_printf(m, "CPUs S-MTID:          %d\n", info->mt_stid);
	}
	/*
	 * Sigh 2. According to the specification the alternate
	 * capability field is a 32 bit floating point number
	 * if the higher order 8 bits are not zero. Printing
	 * a floating point number in the kernel is a no-no,
	 * always print the number as 32 bit unsigned integer.
	 * The user-space needs to know about the strange
	 * encoding of the alternate cpu capability.
	 */
	seq_printf(m, "Capability:           %u", info->capability);
	if (info->format == 1)
		seq_printf(m, " %u", ext->alt_capability);
	seq_putc(m, '\n');
	if (info->nominal_cap)
		seq_printf(m, "Nominal Capability:   %d\n", info->nominal_cap);
	if (info->secondary_cap)
		seq_printf(m, "Secondary Capability: %d\n", info->secondary_cap);
	for (i = 2; i <= info->cpus_total; i++) {
		seq_printf(m, "Adjustment %02d-way:    %u",
			   i, info->adjustment[i-2]);
		if (info->format == 1)
			seq_printf(m, " %u", ext->alt_adjustment[i-2]);
		seq_putc(m, '\n');
	}
}

static void stsi_2_2_2(struct seq_file *m, struct sysinfo_2_2_2 *info)
{
	if (stsi(info, 2, 2, 2))
		return;
	EBCASC(info->name, sizeof(info->name));
	seq_putc(m, '\n');
	seq_printf(m, "LPAR Number:          %d\n", info->lpar_number);
	seq_printf(m, "LPAR Characteristics: ");
	if (info->characteristics & LPAR_CHAR_DEDICATED)
		seq_printf(m, "Dedicated ");
	if (info->characteristics & LPAR_CHAR_SHARED)
		seq_printf(m, "Shared ");
	if (info->characteristics & LPAR_CHAR_LIMITED)
		seq_printf(m, "Limited ");
	seq_putc(m, '\n');
	seq_printf(m, "LPAR Name:            %-8.8s\n", info->name);
	seq_printf(m, "LPAR Adjustment:      %d\n", info->caf);
	seq_printf(m, "LPAR CPUs Total:      %d\n", info->cpus_total);
	seq_printf(m, "LPAR CPUs Configured: %d\n", info->cpus_configured);
	seq_printf(m, "LPAR CPUs Standby:    %d\n", info->cpus_standby);
	seq_printf(m, "LPAR CPUs Reserved:   %d\n", info->cpus_reserved);
	seq_printf(m, "LPAR CPUs Dedicated:  %d\n", info->cpus_dedicated);
	seq_printf(m, "LPAR CPUs Shared:     %d\n", info->cpus_shared);
	if (info->mt_installed) {
		seq_printf(m, "LPAR CPUs G-MTID:     %d\n", info->mt_gtid);
		seq_printf(m, "LPAR CPUs S-MTID:     %d\n", info->mt_stid);
		seq_printf(m, "LPAR CPUs PS-MTID:    %d\n", info->mt_psmtid);
	}
	if (convert_ext_name(info->vsne, info->ext_name, sizeof(info->ext_name))) {
		seq_printf(m, "LPAR Extended Name:   %-.256s\n", info->ext_name);
		seq_printf(m, "LPAR UUID:            %pUb\n", &info->uuid);
	}
}

static void print_ext_name(struct seq_file *m, int lvl,
			   struct sysinfo_3_2_2 *info)
{
	size_t len = sizeof(info->ext_names[lvl]);

	if (!convert_ext_name(info->vm[lvl].evmne, info->ext_names[lvl], len))
		return;
	seq_printf(m, "VM%02d Extended Name:   %-.256s\n", lvl,
		   info->ext_names[lvl]);
}

static void print_uuid(struct seq_file *m, int i, struct sysinfo_3_2_2 *info)
{
	if (!memcmp(&info->vm[i].uuid, &NULL_UUID_BE, sizeof(uuid_be)))
		return;
	seq_printf(m, "VM%02d UUID:            %pUb\n", i, &info->vm[i].uuid);
}

static void stsi_3_2_2(struct seq_file *m, struct sysinfo_3_2_2 *info)
{
	int i;

	if (stsi(info, 3, 2, 2))
		return;
	for (i = 0; i < info->count; i++) {
		EBCASC(info->vm[i].name, sizeof(info->vm[i].name));
		EBCASC(info->vm[i].cpi, sizeof(info->vm[i].cpi));
		seq_putc(m, '\n');
		seq_printf(m, "VM%02d Name:            %-8.8s\n", i, info->vm[i].name);
		seq_printf(m, "VM%02d Control Program: %-16.16s\n", i, info->vm[i].cpi);
		seq_printf(m, "VM%02d Adjustment:      %d\n", i, info->vm[i].caf);
		seq_printf(m, "VM%02d CPUs Total:      %d\n", i, info->vm[i].cpus_total);
		seq_printf(m, "VM%02d CPUs Configured: %d\n", i, info->vm[i].cpus_configured);
		seq_printf(m, "VM%02d CPUs Standby:    %d\n", i, info->vm[i].cpus_standby);
		seq_printf(m, "VM%02d CPUs Reserved:   %d\n", i, info->vm[i].cpus_reserved);
		print_ext_name(m, i, info);
		print_uuid(m, i, info);
	}
}

static int sysinfo_show(struct seq_file *m, void *v)
{
	void *info = (void *)get_zeroed_page(GFP_KERNEL);
	int level;

	if (!info)
		return 0;
	level = stsi(NULL, 0, 0, 0);
	if (level >= 1)
		stsi_1_1_1(m, info);
	if (level >= 1)
		stsi_15_1_x(m, info);
	if (level >= 1)
		stsi_1_2_2(m, info);
	if (level >= 2)
		stsi_2_2_2(m, info);
	if (level >= 3)
		stsi_3_2_2(m, info);
	free_page((unsigned long)info);
	return 0;
}

static int sysinfo_open(struct inode *inode, struct file *file)
{
	return single_open(file, sysinfo_show, NULL);
}

static const struct file_operations sysinfo_fops = {
	.open		= sysinfo_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int __init sysinfo_create_proc(void)
{
	proc_create("sysinfo", 0444, NULL, &sysinfo_fops);
	return 0;
}
device_initcall(sysinfo_create_proc);

/*
 * Service levels interface.
 */

static DECLARE_RWSEM(service_level_sem);
static LIST_HEAD(service_level_list);

int register_service_level(struct service_level *slr)
{
	struct service_level *ptr;

	down_write(&service_level_sem);
	list_for_each_entry(ptr, &service_level_list, list)
		if (ptr == slr) {
			up_write(&service_level_sem);
			return -EEXIST;
		}
	list_add_tail(&slr->list, &service_level_list);
	up_write(&service_level_sem);
	return 0;
}
EXPORT_SYMBOL(register_service_level);

int unregister_service_level(struct service_level *slr)
{
	struct service_level *ptr, *next;
	int rc = -ENOENT;

	down_write(&service_level_sem);
	list_for_each_entry_safe(ptr, next, &service_level_list, list) {
		if (ptr != slr)
			continue;
		list_del(&ptr->list);
		rc = 0;
		break;
	}
	up_write(&service_level_sem);
	return rc;
}
EXPORT_SYMBOL(unregister_service_level);

static void *service_level_start(struct seq_file *m, loff_t *pos)
{
	down_read(&service_level_sem);
	return seq_list_start(&service_level_list, *pos);
}

static void *service_level_next(struct seq_file *m, void *p, loff_t *pos)
{
	return seq_list_next(p, &service_level_list, pos);
}

static void service_level_stop(struct seq_file *m, void *p)
{
	up_read(&service_level_sem);
}

static int service_level_show(struct seq_file *m, void *p)
{
	struct service_level *slr;

	slr = list_entry(p, struct service_level, list);
	slr->seq_print(m, slr);
	return 0;
}

static const struct seq_operations service_level_seq_ops = {
	.start		= service_level_start,
	.next		= service_level_next,
	.stop		= service_level_stop,
	.show		= service_level_show
};

static int service_level_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &service_level_seq_ops);
}

static const struct file_operations service_level_ops = {
	.open		= service_level_open,
	.read		= seq_read,
	.llseek 	= seq_lseek,
	.release	= seq_release
};

static void service_level_vm_print(struct seq_file *m,
				   struct service_level *slr)
{
	char *query_buffer, *str;

	query_buffer = kmalloc(1024, GFP_KERNEL | GFP_DMA);
	if (!query_buffer)
		return;
	cpcmd("QUERY CPLEVEL", query_buffer, 1024, NULL);
	str = strchr(query_buffer, '\n');
	if (str)
		*str = 0;
	seq_printf(m, "VM: %s\n", query_buffer);
	kfree(query_buffer);
}

static struct service_level service_level_vm = {
	.seq_print = service_level_vm_print
};

static __init int create_proc_service_level(void)
{
	proc_create("service_levels", 0, NULL, &service_level_ops);
	if (MACHINE_IS_VM)
		register_service_level(&service_level_vm);
	return 0;
}
subsys_initcall(create_proc_service_level);

/*
 * CPU capability might have changed. Therefore recalculate loops_per_jiffy.
 */
void s390_adjust_jiffies(void)
{
	struct sysinfo_1_2_2 *info;
	unsigned long capability;
	struct kernel_fpu fpu;

	info = (void *) get_zeroed_page(GFP_KERNEL);
	if (!info)
		return;

	if (stsi(info, 1, 2, 2) == 0) {
		/*
		 * Major sigh. The cpu capability encoding is "special".
		 * If the first 9 bits of info->capability are 0 then it
		 * is a 32 bit unsigned integer in the range 0 .. 2^23.
		 * If the first 9 bits are != 0 then it is a 32 bit float.
		 * In addition a lower value indicates a proportionally
		 * higher cpu capacity. Bogomips are the other way round.
		 * To get to a halfway suitable number we divide 1e7
		 * by the cpu capability number. Yes, that means a floating
		 * point division ..
		 */
		kernel_fpu_begin(&fpu, KERNEL_FPR);
		asm volatile(
			"	sfpc	%3\n"
			"	l	%0,%1\n"
			"	tmlh	%0,0xff80\n"
			"	jnz	0f\n"
			"	cefbr	%%f2,%0\n"
			"	j	1f\n"
			"0:	le	%%f2,%1\n"
			"1:	cefbr	%%f0,%2\n"
			"	debr	%%f0,%%f2\n"
			"	cgebr	%0,5,%%f0\n"
			: "=&d" (capability)
			: "Q" (info->capability), "d" (10000000), "d" (0)
			: "cc"
			);
		kernel_fpu_end(&fpu, KERNEL_FPR);
	} else
		/*
		 * Really old machine without stsi block for basic
		 * cpu information. Report 42.0 bogomips.
		 */
		capability = 42;
	loops_per_jiffy = capability * (500000/HZ);
	free_page((unsigned long) info);
}

/*
 * calibrate the delay loop
 */
void calibrate_delay(void)
{
	s390_adjust_jiffies();
	/* Print the good old Bogomips line .. */
	printk(KERN_DEBUG "Calibrating delay loop (skipped)... "
	       "%lu.%02lu BogoMIPS preset\n", loops_per_jiffy/(500000/HZ),
	       (loops_per_jiffy/(5000/HZ)) % 100);
}

#ifdef CONFIG_DEBUG_FS

#define STSI_FILE(fc, s1, s2)						       \
static int stsi_open_##fc##_##s1##_##s2(struct inode *inode, struct file *file)\
{									       \
	file->private_data = (void *) get_zeroed_page(GFP_KERNEL);	       \
	if (!file->private_data)					       \
		return -ENOMEM;						       \
	if (stsi(file->private_data, fc, s1, s2)) {			       \
		free_page((unsigned long)file->private_data);		       \
		file->private_data = NULL;				       \
		return -EACCES;						       \
	}								       \
	return nonseekable_open(inode, file);				       \
}									       \
									       \
static const struct file_operations stsi_##fc##_##s1##_##s2##_fs_ops = {       \
	.open		= stsi_open_##fc##_##s1##_##s2,			       \
	.release	= stsi_release,					       \
	.read		= stsi_read,					       \
	.llseek		= no_llseek,					       \
};

static int stsi_release(struct inode *inode, struct file *file)
{
	free_page((unsigned long)file->private_data);
	return 0;
}

static ssize_t stsi_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
{
	return simple_read_from_buffer(buf, size, ppos, file->private_data, PAGE_SIZE);
}

STSI_FILE(15, 1, 2);
STSI_FILE(15, 1, 3);
STSI_FILE(15, 1, 4);
STSI_FILE(15, 1, 5);
STSI_FILE(15, 1, 6);

struct stsi_file {
	const struct file_operations *fops;
	char *name;
};

static struct stsi_file stsi_file[] __initdata = {
	{.fops = &stsi_15_1_2_fs_ops, .name = "15_1_2"},
	{.fops = &stsi_15_1_3_fs_ops, .name = "15_1_3"},
	{.fops = &stsi_15_1_4_fs_ops, .name = "15_1_4"},
	{.fops = &stsi_15_1_5_fs_ops, .name = "15_1_5"},
	{.fops = &stsi_15_1_6_fs_ops, .name = "15_1_6"},
};

static __init int stsi_init_debugfs(void)
{
	struct dentry *stsi_root;
	struct stsi_file *sf;
	int i;

	stsi_root = debugfs_create_dir("stsi", arch_debugfs_dir);
	if (IS_ERR_OR_NULL(stsi_root))
		return 0;
	for (i = 0; i < ARRAY_SIZE(stsi_file); i++) {
		sf = &stsi_file[i];
		debugfs_create_file(sf->name, 0400, stsi_root, NULL, sf->fops);
	}
	if (IS_ENABLED(CONFIG_SCHED_TOPOLOGY) && MACHINE_HAS_TOPOLOGY) {
		char link_to[10];

		sprintf(link_to, "15_1_%d", topology_mnest_limit());
		debugfs_create_symlink("topology", stsi_root, link_to);
	}
	return 0;
}
device_initcall(stsi_init_debugfs);

#endif /* CONFIG_DEBUG_FS */