text: /*
   * 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 "../../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 __user *usr_buffer, int usr_buffer_nob);
  int cfs_trace_copyout_string(char __user *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 __user *usr_str, int usr_str_nob);
  int cfs_trace_daemon_command(char *str);
  int cfs_trace_daemon_command_usrstr(void __user *usr_str, int usr_str_nob);
  int cfs_trace_set_debug_mb(int mb);
  int cfs_trace_set_debug_mb_usrstr(void __user *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, gfp_t 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__ */
  