/*
 * 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.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * 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.
 */

#ifndef __LIBCFS_TRACEFILE_H__
#define __LIBCFS_TRACEFILE_H__

#include <linux/libcfs/libcfs.h>

#include "linux/linux-tracefile.h"

/* trace file lock routines */

#define TRACEFILE_NAME_SIZE 1024
extern char      cfs_tracefile[TRACEFILE_NAME_SIZE];
extern long long cfs_tracefile_size;

extern void libcfs_run_debug_log_upcall(char *file);

int  cfs_tracefile_init_arch(void);
void cfs_tracefile_fini_arch(void);

void cfs_tracefile_read_lock(void);
void cfs_tracefile_read_unlock(void);
void cfs_tracefile_write_lock(void);
void cfs_tracefile_write_unlock(void);

int cfs_tracefile_dump_all_pages(char *filename);
void cfs_trace_debug_print(void);
void cfs_trace_flush_pages(void);
int cfs_trace_start_thread(void);
void cfs_trace_stop_thread(void);
int cfs_tracefile_init(int max_pages);
void cfs_tracefile_exit(void);



int cfs_trace_copyin_string(char *knl_buffer, int knl_buffer_nob,
                            const char *usr_buffer, int usr_buffer_nob);
int cfs_trace_copyout_string(char *usr_buffer, int usr_buffer_nob,
                             const char *knl_str, char *append);
int cfs_trace_allocate_string_buffer(char **str, int nob);
void cfs_trace_free_string_buffer(char *str, int nob);
int cfs_trace_dump_debug_buffer_usrstr(void *usr_str, int usr_str_nob);
int cfs_trace_daemon_command(char *str);
int cfs_trace_daemon_command_usrstr(void *usr_str, int usr_str_nob);
int cfs_trace_set_debug_mb(int mb);
int cfs_trace_set_debug_mb_usrstr(void *usr_str, int usr_str_nob);
int cfs_trace_get_debug_mb(void);

extern void libcfs_debug_dumplog_internal(void *arg);
extern void libcfs_register_panic_notifier(void);
extern void libcfs_unregister_panic_notifier(void);
extern int  libcfs_panic_in_progress;
extern int  cfs_trace_max_debug_mb(void);

#define TCD_MAX_PAGES (5 << (20 - PAGE_CACHE_SHIFT))
#define TCD_STOCK_PAGES (TCD_MAX_PAGES)
#define CFS_TRACEFILE_SIZE (500 << 20)

#ifdef LUSTRE_TRACEFILE_PRIVATE

/*
 * Private declare for tracefile
 */
#define TCD_MAX_PAGES (5 << (20 - PAGE_CACHE_SHIFT))
#define TCD_STOCK_PAGES (TCD_MAX_PAGES)

#define CFS_TRACEFILE_SIZE (500 << 20)

/* Size of a buffer for sprinting console messages if we can't get a page
 * from system */
#define CFS_TRACE_CONSOLE_BUFFER_SIZE   1024

union cfs_trace_data_union {
        struct cfs_trace_cpu_data {
                /*
                 * Even though this structure is meant to be per-CPU, locking
                 * is needed because in some places the data may be accessed
                 * from other CPUs. This lock is directly used in trace_get_tcd
                 * and trace_put_tcd, which are called in libcfs_debug_vmsg2 and
                 * tcd_for_each_type_lock
                 */
                spinlock_t              tcd_lock;
                unsigned long      tcd_lock_flags;

                /*
                 * pages with trace records not yet processed by tracefiled.
                 */
                struct list_head              tcd_pages;
                /* number of pages on ->tcd_pages */
                unsigned long      tcd_cur_pages;

                /*
                 * pages with trace records already processed by
                 * tracefiled. These pages are kept in memory, so that some
                 * portion of log can be written in the event of LBUG. This
                 * list is maintained in LRU order.
                 *
                 * Pages are moved to ->tcd_daemon_pages by tracefiled()
                 * (put_pages_on_daemon_list()). LRU pages from this list are
                 * discarded when list grows too large.
                 */
                struct list_head              tcd_daemon_pages;
                /* number of pages on ->tcd_daemon_pages */
                unsigned long      tcd_cur_daemon_pages;

                /*
                 * Maximal number of pages allowed on ->tcd_pages and
                 * ->tcd_daemon_pages each.
                 * Always TCD_MAX_PAGES * tcd_pages_factor / 100 in current
                 * implementation.
                 */
                unsigned long      tcd_max_pages;

                /*
                 * preallocated pages to write trace records into. Pages from
                 * ->tcd_stock_pages are moved to ->tcd_pages by
                 * portals_debug_msg().
                 *
                 * This list is necessary, because on some platforms it's
                 * impossible to perform efficient atomic page allocation in a
                 * non-blockable context.
                 *
                 * Such platforms fill ->tcd_stock_pages "on occasion", when
                 * tracing code is entered in blockable context.
                 *
                 * trace_get_tage_try() tries to get a page from
                 * ->tcd_stock_pages first and resorts to atomic page
                 * allocation only if this queue is empty. ->tcd_stock_pages
                 * is replenished when tracing code is entered in blocking
                 * context (darwin-tracefile.c:trace_get_tcd()). We try to
                 * maintain TCD_STOCK_PAGES (40 by default) pages in this
                 * queue. Atomic allocation is only required if more than
                 * TCD_STOCK_PAGES pagesful are consumed by trace records all
                 * emitted in non-blocking contexts. Which is quite unlikely.
                 */
                struct list_head              tcd_stock_pages;
                /* number of pages on ->tcd_stock_pages */
                unsigned long      tcd_cur_stock_pages;

                unsigned short    tcd_shutting_down;
                unsigned short    tcd_cpu;
                unsigned short    tcd_type;
                /* The factors to share debug memory. */
                unsigned short    tcd_pages_factor;
        } tcd;
        char __pad[L1_CACHE_ALIGN(sizeof(struct cfs_trace_cpu_data))];
};

#define TCD_MAX_TYPES      8
extern union cfs_trace_data_union (*cfs_trace_data[TCD_MAX_TYPES])[NR_CPUS];

#define cfs_tcd_for_each(tcd, i, j)                                    \
    for (i = 0; cfs_trace_data[i] != NULL; i++)                    \
        for (j = 0, ((tcd) = &(*cfs_trace_data[i])[j].tcd);            \
             j < num_possible_cpus();                            \
             j++, (tcd) = &(*cfs_trace_data[i])[j].tcd)

#define cfs_tcd_for_each_type_lock(tcd, i, cpu)                    \
    for (i = 0; cfs_trace_data[i] &&                                  \
         (tcd = &(*cfs_trace_data[i])[cpu].tcd) &&                      \
         cfs_trace_lock_tcd(tcd, 1); cfs_trace_unlock_tcd(tcd, 1), i++)

/* XXX nikita: this declaration is internal to tracefile.c and should probably
 * be moved there */
struct page_collection {
        struct list_head        pc_pages;
        /*
         * spin-lock protecting ->pc_pages. It is taken by smp_call_function()
         * call-back functions. XXX nikita: Which is horrible: all processors
         * receive NMI at the same time only to be serialized by this
         * lock. Probably ->pc_pages should be replaced with an array of
         * NR_CPUS elements accessed locklessly.
         */
        spinlock_t      pc_lock;
        /*
         * if this flag is set, collect_pages() will spill both
         * ->tcd_daemon_pages and ->tcd_pages to the ->pc_pages. Otherwise,
         * only ->tcd_pages are spilled.
         */
        int             pc_want_daemon_pages;
};

/* XXX nikita: this declaration is internal to tracefile.c and should probably
 * be moved there */
struct tracefiled_ctl {
        struct completion       tctl_start;
        struct completion       tctl_stop;
        wait_queue_head_t               tctl_waitq;
        pid_t                   tctl_pid;
        atomic_t                tctl_shutdown;
};

/*
 * small data-structure for each page owned by tracefiled.
 */
/* XXX nikita: this declaration is internal to tracefile.c and should probably
 * be moved there */
struct cfs_trace_page {
        /*
         * page itself
         */
        struct page       *page;
        /*
         * linkage into one of the lists in trace_data_union or
         * page_collection
         */
        struct list_head           linkage;
        /*
         * number of bytes used within this page
         */
        unsigned int     used;
        /*
         * cpu that owns this page
         */
        unsigned short       cpu;
        /*
         * type(context) of this page
         */
        unsigned short       type;
};

extern void cfs_set_ptldebug_header(struct ptldebug_header *header,
                                    struct libcfs_debug_msg_data *m,
                                    unsigned long stack);
extern void cfs_print_to_console(struct ptldebug_header *hdr, int mask,
                                 const char *buf, int len, const char *file,
                                 const char *fn);

extern int cfs_trace_lock_tcd(struct cfs_trace_cpu_data *tcd, int walking);
extern void cfs_trace_unlock_tcd(struct cfs_trace_cpu_data *tcd, int walking);

/**
 * trace_buf_type_t, trace_buf_idx_get() and trace_console_buffers[][]
 * are not public libcfs API; they should be defined in
 * platform-specific tracefile include files
 * (see, for example, linux-tracefile.h).
 */

extern char *cfs_trace_console_buffers[NR_CPUS][CFS_TCD_TYPE_MAX];
extern cfs_trace_buf_type_t cfs_trace_buf_idx_get(void);

static inline char *
cfs_trace_get_console_buffer(void)
{
        unsigned int i = get_cpu();
        unsigned int j = cfs_trace_buf_idx_get();

        return cfs_trace_console_buffers[i][j];
}

static inline void
cfs_trace_put_console_buffer(char *buffer)
{
        put_cpu();
}

static inline struct cfs_trace_cpu_data *
cfs_trace_get_tcd(void)
{
        struct cfs_trace_cpu_data *tcd =
                &(*cfs_trace_data[cfs_trace_buf_idx_get()])[get_cpu()].tcd;

        cfs_trace_lock_tcd(tcd, 0);

        return tcd;
}

static inline void
cfs_trace_put_tcd (struct cfs_trace_cpu_data *tcd)
{
        cfs_trace_unlock_tcd(tcd, 0);

        put_cpu();
}

int cfs_trace_refill_stock(struct cfs_trace_cpu_data *tcd, int gfp,
                           struct list_head *stock);


int cfs_tcd_owns_tage(struct cfs_trace_cpu_data *tcd,
                      struct cfs_trace_page *tage);

extern void cfs_trace_assertion_failed(const char *str,
                                       struct libcfs_debug_msg_data *m);

/* ASSERTION that is safe to use within the debug system */
#define __LASSERT(cond)                                          \
do {                                                                \
        if (unlikely(!(cond))) {                                        \
                LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_EMERG, NULL);     \
                cfs_trace_assertion_failed("ASSERTION("#cond") failed", \
                                           &msgdata);              \
        }                                                              \
} while (0)

#define __LASSERT_TAGE_INVARIANT(tage)                            \
do {                                                                \
        __LASSERT(tage != NULL);                                        \
        __LASSERT(tage->page != NULL);                            \
        __LASSERT(tage->used <= PAGE_CACHE_SIZE);                        \
        __LASSERT(page_count(tage->page) > 0);                \
} while (0)

#endif  /* LUSTRE_TRACEFILE_PRIVATE */

#endif /* __LIBCFS_TRACEFILE_H__ */