/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_LNET
#define LUSTRE_TRACEFILE_PRIVATE

#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/poll.h>
#include <linux/mm.h>
#include "tracefile.h"

/* percents to share the total debug memory for each type */
static unsigned int pages_factor[CFS_TCD_TYPE_MAX] = {
	80,  /* 80% pages for CFS_TCD_TYPE_PROC */
	10,  /* 10% pages for CFS_TCD_TYPE_SOFTIRQ */
	10   /* 10% pages for CFS_TCD_TYPE_IRQ */
};

char *cfs_trace_console_buffers[NR_CPUS][CFS_TCD_TYPE_MAX];

static DECLARE_RWSEM(cfs_tracefile_sem);

int cfs_tracefile_init_arch(void)
{
	int i;
	int j;
	struct cfs_trace_cpu_data *tcd;

	/* initialize trace_data */
	memset(cfs_trace_data, 0, sizeof(cfs_trace_data));
	for (i = 0; i < CFS_TCD_TYPE_MAX; i++) {
		cfs_trace_data[i] =
			kmalloc_array(num_possible_cpus(),
				      sizeof(union cfs_trace_data_union),
				      GFP_KERNEL);
		if (!cfs_trace_data[i])
			goto out;
	}

	/* arch related info initialized */
	cfs_tcd_for_each(tcd, i, j) {
		spin_lock_init(&tcd->tcd_lock);
		tcd->tcd_pages_factor = pages_factor[i];
		tcd->tcd_type = i;
		tcd->tcd_cpu = j;
	}

	for (i = 0; i < num_possible_cpus(); i++)
		for (j = 0; j < 3; j++) {
			cfs_trace_console_buffers[i][j] =
				kmalloc(CFS_TRACE_CONSOLE_BUFFER_SIZE,
					GFP_KERNEL);

			if (!cfs_trace_console_buffers[i][j])
				goto out;
		}

	return 0;

out:
	cfs_tracefile_fini_arch();
	pr_err("lnet: Not enough memory\n");
	return -ENOMEM;
}

void cfs_tracefile_fini_arch(void)
{
	int i;
	int j;

	for (i = 0; i < num_possible_cpus(); i++)
		for (j = 0; j < 3; j++) {
			kfree(cfs_trace_console_buffers[i][j]);
			cfs_trace_console_buffers[i][j] = NULL;
		}

	for (i = 0; cfs_trace_data[i]; i++) {
		kfree(cfs_trace_data[i]);
		cfs_trace_data[i] = NULL;
	}
}

void cfs_tracefile_read_lock(void)
{
	down_read(&cfs_tracefile_sem);
}

void cfs_tracefile_read_unlock(void)
{
	up_read(&cfs_tracefile_sem);
}

void cfs_tracefile_write_lock(void)
{
	down_write(&cfs_tracefile_sem);
}

void cfs_tracefile_write_unlock(void)
{
	up_write(&cfs_tracefile_sem);
}

enum cfs_trace_buf_type cfs_trace_buf_idx_get(void)
{
	if (in_irq())
		return CFS_TCD_TYPE_IRQ;
	if (in_softirq())
		return CFS_TCD_TYPE_SOFTIRQ;
	return CFS_TCD_TYPE_PROC;
}

/*
 * The walking argument indicates the locking comes from all tcd types
 * iterator and we must lock it and dissable local irqs to avoid deadlocks
 * with other interrupt locks that might be happening. See LU-1311
 * for details.
 */
int cfs_trace_lock_tcd(struct cfs_trace_cpu_data *tcd, int walking)
	__acquires(&tcd->tcd_lock)
{
	__LASSERT(tcd->tcd_type < CFS_TCD_TYPE_MAX);
	if (tcd->tcd_type == CFS_TCD_TYPE_IRQ)
		spin_lock_irqsave(&tcd->tcd_lock, tcd->tcd_lock_flags);
	else if (tcd->tcd_type == CFS_TCD_TYPE_SOFTIRQ)
		spin_lock_bh(&tcd->tcd_lock);
	else if (unlikely(walking))
		spin_lock_irq(&tcd->tcd_lock);
	else
		spin_lock(&tcd->tcd_lock);
	return 1;
}

void cfs_trace_unlock_tcd(struct cfs_trace_cpu_data *tcd, int walking)
	__releases(&tcd->tcd_lock)
{
	__LASSERT(tcd->tcd_type < CFS_TCD_TYPE_MAX);
	if (tcd->tcd_type == CFS_TCD_TYPE_IRQ)
		spin_unlock_irqrestore(&tcd->tcd_lock, tcd->tcd_lock_flags);
	else if (tcd->tcd_type == CFS_TCD_TYPE_SOFTIRQ)
		spin_unlock_bh(&tcd->tcd_lock);
	else if (unlikely(walking))
		spin_unlock_irq(&tcd->tcd_lock);
	else
		spin_unlock(&tcd->tcd_lock);
}

int cfs_tcd_owns_tage(struct cfs_trace_cpu_data *tcd,
		      struct cfs_trace_page *tage)
{
	/*
	 * XXX nikita: do NOT call portals_debug_msg() (CDEBUG/ENTRY/EXIT)
	 * from here: this will lead to infinite recursion.
	 */
	return tcd->tcd_cpu == tage->cpu;
}

void
cfs_set_ptldebug_header(struct ptldebug_header *header,
			struct libcfs_debug_msg_data *msgdata,
			unsigned long stack)
{
	struct timespec64 ts;

	ktime_get_real_ts64(&ts);

	header->ph_subsys = msgdata->msg_subsys;
	header->ph_mask = msgdata->msg_mask;
	header->ph_cpu_id = smp_processor_id();
	header->ph_type = cfs_trace_buf_idx_get();
	/* y2038 safe since all user space treats this as unsigned, but
	 * will overflow in 2106
	 */
	header->ph_sec = (u32)ts.tv_sec;
	header->ph_usec = ts.tv_nsec / NSEC_PER_USEC;
	header->ph_stack = stack;
	header->ph_pid = current->pid;
	header->ph_line_num = msgdata->msg_line;
	header->ph_extern_pid = 0;
}

/**
 * tty_write_msg - write a message to a certain tty, not just the console.
 * @tty: the destination tty_struct
 * @msg: the message to write
 *
 * tty_write_message is not exported, so write a same function for it
 *
 */
static void tty_write_msg(struct tty_struct *tty, const char *msg)
{
	mutex_lock(&tty->atomic_write_lock);
	tty_lock(tty);
	if (tty->ops->write && tty->count > 0)
		tty->ops->write(tty, msg, strlen(msg));
	tty_unlock(tty);
	mutex_unlock(&tty->atomic_write_lock);
	wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
}

static void cfs_tty_write_message(const char *prefix, int mask, const char *msg)
{
	struct tty_struct *tty;

	tty = get_current_tty();
	if (!tty)
		return;

	tty_write_msg(tty, prefix);
	if ((mask & D_EMERG) || (mask & D_ERROR))
		tty_write_msg(tty, "Error");
	tty_write_msg(tty, ": ");
	tty_write_msg(tty, msg);
	tty_kref_put(tty);
}

void cfs_print_to_console(struct ptldebug_header *hdr, int mask,
			  const char *buf, int len, const char *file,
			  const char *fn)
{
	char *prefix = "Lustre";

	if (hdr->ph_subsys == S_LND || hdr->ph_subsys == S_LNET)
		prefix = "LNet";

	if (mask & D_CONSOLE) {
		if (mask & D_EMERG)
			pr_emerg("%sError: %.*s", prefix, len, buf);
		else if (mask & D_ERROR)
			pr_err("%sError: %.*s", prefix, len, buf);
		else if (mask & D_WARNING)
			pr_warn("%s: %.*s", prefix, len, buf);
		else if (mask & libcfs_printk)
			pr_info("%s: %.*s", prefix, len, buf);
	} else {
		if (mask & D_EMERG)
			pr_emerg("%sError: %d:%d:(%s:%d:%s()) %.*s", prefix,
				 hdr->ph_pid, hdr->ph_extern_pid, file,
				 hdr->ph_line_num, fn, len, buf);
		else if (mask & D_ERROR)
			pr_err("%sError: %d:%d:(%s:%d:%s()) %.*s", prefix,
			       hdr->ph_pid, hdr->ph_extern_pid, file,
			       hdr->ph_line_num, fn, len, buf);
		else if (mask & D_WARNING)
			pr_warn("%s: %d:%d:(%s:%d:%s()) %.*s", prefix,
				hdr->ph_pid, hdr->ph_extern_pid, file,
				hdr->ph_line_num, fn, len, buf);
			else if (mask & (D_CONSOLE | libcfs_printk))
				pr_info("%s: %.*s", prefix, len, buf);
	}

	if (mask & D_TTY)
		cfs_tty_write_message(prefix, mask, buf);
}

int cfs_trace_max_debug_mb(void)
{
	int total_mb = (cfs_totalram_pages() >> (20 - PAGE_SHIFT));

	return max(512, (total_mb * 80) / 100);
}