527 lines
15 KiB
C
527 lines
15 KiB
C
/*
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* Linux WiMAX
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* Collection of tools to manage debug operations.
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*
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*
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* Copyright (C) 2005-2007 Intel Corporation
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* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301, USA.
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*
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*
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* Don't #include this file directly, read on!
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*
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*
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* EXECUTING DEBUGGING ACTIONS OR NOT
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*
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* The main thing this framework provides is decission power to take a
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* debug action (like printing a message) if the current debug level
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* allows it.
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*
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* The decission power is at two levels: at compile-time (what does
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* not make it is compiled out) and at run-time. The run-time
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* selection is done per-submodule (as they are declared by the user
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* of the framework).
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*
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* A call to d_test(L) (L being the target debug level) returns true
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* if the action should be taken because the current debug levels
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* allow it (both compile and run time).
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*
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* It follows that a call to d_test() that can be determined to be
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* always false at compile time will get the code depending on it
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* compiled out by optimization.
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*
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*
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* DEBUG LEVELS
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*
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* It is up to the caller to define how much a debugging level is.
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*
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* Convention sets 0 as "no debug" (so an action marked as debug level 0
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* will always be taken). The increasing debug levels are used for
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* increased verbosity.
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*
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*
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* USAGE
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*
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* Group the code in modules and submodules inside each module [which
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* in most cases maps to Linux modules and .c files that compose
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* those].
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*
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*
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* For each module, there is:
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*
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* - a MODULENAME (single word, legal C identifier)
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*
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* - a debug-levels.h header file that declares the list of
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* submodules and that is included by all .c files that use
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* the debugging tools. The file name can be anything.
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*
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* - some (optional) .c code to manipulate the runtime debug levels
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* through debugfs.
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*
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* The debug-levels.h file would look like:
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*
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* #ifndef __debug_levels__h__
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* #define __debug_levels__h__
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*
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* #define D_MODULENAME modulename
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* #define D_MASTER 10
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*
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* #include <linux/wimax/debug.h>
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*
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* enum d_module {
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* D_SUBMODULE_DECLARE(submodule_1),
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* D_SUBMODULE_DECLARE(submodule_2),
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* ...
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* D_SUBMODULE_DECLARE(submodule_N)
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* };
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*
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* #endif
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*
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* D_MASTER is the maximum compile-time debug level; any debug actions
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* above this will be out. D_MODULENAME is the module name (legal C
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* identifier), which has to be unique for each module (to avoid
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* namespace collisions during linkage). Note those #defines need to
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* be done before #including debug.h
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*
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* We declare N different submodules whose debug level can be
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* independently controlled during runtime.
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*
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* In a .c file of the module (and only in one of them), define the
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* following code:
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*
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* struct d_level D_LEVEL[] = {
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* D_SUBMODULE_DEFINE(submodule_1),
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* D_SUBMODULE_DEFINE(submodule_2),
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* ...
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* D_SUBMODULE_DEFINE(submodule_N),
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* };
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* size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
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*
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* Externs for d_level_MODULENAME and d_level_size_MODULENAME are used
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* and declared in this file using the D_LEVEL and D_LEVEL_SIZE macros
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* #defined also in this file.
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*
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* To manipulate from user space the levels, create a debugfs dentry
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* and then register each submodule with:
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*
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* result = d_level_register_debugfs("PREFIX_", submodule_X, parent);
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* if (result < 0)
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* goto error;
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*
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* Where PREFIX_ is a name of your chosing. This will create debugfs
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* file with a single numeric value that can be use to tweak it. To
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* remove the entires, just use debugfs_remove_recursive() on 'parent'.
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*
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* NOTE: remember that even if this will show attached to some
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* particular instance of a device, the settings are *global*.
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*
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*
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* On each submodule (for example, .c files), the debug infrastructure
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* should be included like this:
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*
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* #define D_SUBMODULE submodule_x // matches one in debug-levels.h
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* #include "debug-levels.h"
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*
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* after #including all your include files.
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*
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*
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* Now you can use the d_*() macros below [d_test(), d_fnstart(),
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* d_fnend(), d_printf(), d_dump()].
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*
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* If their debug level is greater than D_MASTER, they will be
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* compiled out.
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*
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* If their debug level is lower or equal than D_MASTER but greater
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* than the current debug level of their submodule, they'll be
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* ignored.
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*
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* Otherwise, the action will be performed.
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*/
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#ifndef __debug__h__
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#define __debug__h__
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#include <linux/types.h>
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#include <linux/slab.h>
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struct device;
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/* Backend stuff */
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/*
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* Debug backend: generate a message header from a 'struct device'
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*
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* @head: buffer where to place the header
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* @head_size: length of @head
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* @dev: pointer to device used to generate a header from. If NULL,
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* an empty ("") header is generated.
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*/
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static inline
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void __d_head(char *head, size_t head_size,
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struct device *dev)
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{
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if (dev == NULL)
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head[0] = 0;
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else if ((unsigned long)dev < 4096) {
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printk(KERN_ERR "E: Corrupt dev %p\n", dev);
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WARN_ON(1);
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} else
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snprintf(head, head_size, "%s %s: ",
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dev_driver_string(dev), dev_name(dev));
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}
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/*
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* Debug backend: log some message if debugging is enabled
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*
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* @l: intended debug level
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* @tag: tag to prefix the message with
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* @dev: 'struct device' associated to this message
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* @f: printf-like format and arguments
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*
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* Note this is optimized out if it doesn't pass the compile-time
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* check; however, it is *always* compiled. This is useful to make
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* sure the printf-like formats and variables are always checked and
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* they don't get bit rot if you have all the debugging disabled.
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*/
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#define _d_printf(l, tag, dev, f, a...) \
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do { \
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char head[64]; \
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if (!d_test(l)) \
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break; \
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__d_head(head, sizeof(head), dev); \
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printk(KERN_ERR "%s%s%s: " f, head, __func__, tag, ##a); \
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} while (0)
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/*
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* CPP sintatic sugar to generate A_B like symbol names when one of
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* the arguments is a a preprocessor #define.
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*/
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#define __D_PASTE__(varname, modulename) varname##_##modulename
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#define __D_PASTE(varname, modulename) (__D_PASTE__(varname, modulename))
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#define _D_SUBMODULE_INDEX(_name) (D_SUBMODULE_DECLARE(_name))
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/*
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* Store a submodule's runtime debug level and name
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*/
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struct d_level {
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u8 level;
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const char *name;
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};
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/*
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* List of available submodules and their debug levels
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*
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* We call them d_level_MODULENAME and d_level_size_MODULENAME; the
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* macros D_LEVEL and D_LEVEL_SIZE contain the name already for
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* convenience.
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*
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* This array and the size are defined on some .c file that is part of
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* the current module.
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*/
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#define D_LEVEL __D_PASTE(d_level, D_MODULENAME)
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#define D_LEVEL_SIZE __D_PASTE(d_level_size, D_MODULENAME)
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extern struct d_level D_LEVEL[];
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extern size_t D_LEVEL_SIZE;
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/*
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* Frontend stuff
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*
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*
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* Stuff you need to declare prior to using the actual "debug" actions
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* (defined below).
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*/
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#ifndef D_MODULENAME
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#error D_MODULENAME is not defined in your debug-levels.h file
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/**
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* D_MODULE - Name of the current module
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*
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* #define in your module's debug-levels.h, making sure it is
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* unique. This has to be a legal C identifier.
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*/
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#define D_MODULENAME undefined_modulename
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#endif
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#ifndef D_MASTER
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#warning D_MASTER not defined, but debug.h included! [see docs]
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/**
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* D_MASTER - Compile time maximum debug level
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*
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* #define in your debug-levels.h file to the maximum debug level the
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* runtime code will be allowed to have. This allows you to provide a
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* main knob.
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*
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* Anything above that level will be optimized out of the compile.
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*
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* Defaults to zero (no debug code compiled in).
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*
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* Maximum one definition per module (at the debug-levels.h file).
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*/
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#define D_MASTER 0
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#endif
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#ifndef D_SUBMODULE
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#error D_SUBMODULE not defined, but debug.h included! [see docs]
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/**
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* D_SUBMODULE - Name of the current submodule
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*
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* #define in your submodule .c file before #including debug-levels.h
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* to the name of the current submodule as previously declared and
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* defined with D_SUBMODULE_DECLARE() (in your module's
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* debug-levels.h) and D_SUBMODULE_DEFINE().
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*
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* This is used to provide runtime-control over the debug levels.
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*
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* Maximum one per .c file! Can be shared among different .c files
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* (meaning they belong to the same submodule categorization).
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*/
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#define D_SUBMODULE undefined_module
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#endif
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/**
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* D_SUBMODULE_DECLARE - Declare a submodule for runtime debug level control
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*
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* @_name: name of the submodule, restricted to the chars that make up a
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* valid C identifier ([a-zA-Z0-9_]).
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*
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* Declare in the module's debug-levels.h header file as:
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*
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* enum d_module {
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* D_SUBMODULE_DECLARE(submodule_1),
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* D_SUBMODULE_DECLARE(submodule_2),
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* D_SUBMODULE_DECLARE(submodule_3),
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* };
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*
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* Some corresponding .c file needs to have a matching
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* D_SUBMODULE_DEFINE().
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*/
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#define D_SUBMODULE_DECLARE(_name) __D_SUBMODULE_##_name
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/**
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* D_SUBMODULE_DEFINE - Define a submodule for runtime debug level control
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*
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* @_name: name of the submodule, restricted to the chars that make up a
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* valid C identifier ([a-zA-Z0-9_]).
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*
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* Use once per module (in some .c file) as:
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*
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* static
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* struct d_level d_level_SUBMODULENAME[] = {
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* D_SUBMODULE_DEFINE(submodule_1),
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* D_SUBMODULE_DEFINE(submodule_2),
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* D_SUBMODULE_DEFINE(submodule_3),
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* };
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* size_t d_level_size_SUBDMODULENAME = ARRAY_SIZE(d_level_SUBDMODULENAME);
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*
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* Matching D_SUBMODULE_DECLARE()s have to be present in a
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* debug-levels.h header file.
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*/
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#define D_SUBMODULE_DEFINE(_name) \
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[__D_SUBMODULE_##_name] = { \
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.level = 0, \
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.name = #_name \
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}
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/* The actual "debug" operations */
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/**
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* d_test - Returns true if debugging should be enabled
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*
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* @l: intended debug level (unsigned)
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*
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* If the master debug switch is enabled and the current settings are
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* higher or equal to the requested level, then debugging
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* output/actions should be enabled.
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*
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* NOTE:
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*
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* This needs to be coded so that it can be evaluated in compile
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* time; this is why the ugly BUG_ON() is placed in there, so the
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* D_MASTER evaluation compiles all out if it is compile-time false.
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*/
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#define d_test(l) \
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({ \
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unsigned __l = l; /* type enforcer */ \
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(D_MASTER) >= __l \
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&& ({ \
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BUG_ON(_D_SUBMODULE_INDEX(D_SUBMODULE) >= D_LEVEL_SIZE);\
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D_LEVEL[_D_SUBMODULE_INDEX(D_SUBMODULE)].level >= __l; \
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}); \
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})
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/**
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* d_fnstart - log message at function start if debugging enabled
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*
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* @l: intended debug level
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* @_dev: 'struct device' pointer, NULL if none (for context)
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* @f: printf-like format and arguments
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*/
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#define d_fnstart(l, _dev, f, a...) _d_printf(l, " FNSTART", _dev, f, ## a)
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/**
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* d_fnend - log message at function end if debugging enabled
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*
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* @l: intended debug level
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* @_dev: 'struct device' pointer, NULL if none (for context)
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* @f: printf-like format and arguments
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*/
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#define d_fnend(l, _dev, f, a...) _d_printf(l, " FNEND", _dev, f, ## a)
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/**
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* d_printf - log message if debugging enabled
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*
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* @l: intended debug level
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* @_dev: 'struct device' pointer, NULL if none (for context)
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* @f: printf-like format and arguments
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*/
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#define d_printf(l, _dev, f, a...) _d_printf(l, "", _dev, f, ## a)
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/**
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* d_dump - log buffer hex dump if debugging enabled
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*
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* @l: intended debug level
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* @_dev: 'struct device' pointer, NULL if none (for context)
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* @f: printf-like format and arguments
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*/
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#define d_dump(l, dev, ptr, size) \
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do { \
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char head[64]; \
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if (!d_test(l)) \
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break; \
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__d_head(head, sizeof(head), dev); \
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print_hex_dump(KERN_ERR, head, 0, 16, 1, \
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((void *) ptr), (size), 0); \
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} while (0)
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/**
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* Export a submodule's debug level over debugfs as PREFIXSUBMODULE
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*
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* @prefix: string to prefix the name with
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* @submodule: name of submodule (not a string, just the name)
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* @dentry: debugfs parent dentry
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*
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* Returns: 0 if ok, < 0 errno on error.
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*
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* For removing, just use debugfs_remove_recursive() on the parent.
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*/
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#define d_level_register_debugfs(prefix, name, parent) \
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({ \
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int rc; \
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struct dentry *fd; \
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struct dentry *verify_parent_type = parent; \
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fd = debugfs_create_u8( \
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prefix #name, 0600, verify_parent_type, \
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&(D_LEVEL[__D_SUBMODULE_ ## name].level)); \
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rc = PTR_ERR(fd); \
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if (IS_ERR(fd) && rc != -ENODEV) \
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printk(KERN_ERR "%s: Can't create debugfs entry %s: " \
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"%d\n", __func__, prefix #name, rc); \
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else \
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rc = 0; \
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rc; \
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})
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static inline
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void d_submodule_set(struct d_level *d_level, size_t d_level_size,
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const char *submodule, u8 level, const char *tag)
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{
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struct d_level *itr, *top;
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int index = -1;
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for (itr = d_level, top = itr + d_level_size; itr < top; itr++) {
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index++;
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if (itr->name == NULL) {
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printk(KERN_ERR "%s: itr->name NULL?? (%p, #%d)\n",
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tag, itr, index);
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continue;
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}
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if (!strcmp(itr->name, submodule)) {
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itr->level = level;
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return;
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}
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}
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printk(KERN_ERR "%s: unknown submodule %s\n", tag, submodule);
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}
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/**
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* d_parse_params - Parse a string with debug parameters from the
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* command line
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*
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* @d_level: level structure (D_LEVEL)
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* @d_level_size: number of items in the level structure
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* (D_LEVEL_SIZE).
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* @_params: string with the parameters; this is a space (not tab!)
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* separated list of NAME:VALUE, where value is the debug level
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* and NAME is the name of the submodule.
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* @tag: string for error messages (example: MODULE.ARGNAME).
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*/
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static inline
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void d_parse_params(struct d_level *d_level, size_t d_level_size,
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const char *_params, const char *tag)
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{
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char submodule[130], *params, *params_orig, *token, *colon;
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unsigned level, tokens;
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if (_params == NULL)
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return;
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params_orig = kstrdup(_params, GFP_KERNEL);
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params = params_orig;
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while (1) {
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token = strsep(¶ms, " ");
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if (token == NULL)
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break;
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if (*token == '\0') /* eat joint spaces */
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continue;
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/* kernel's sscanf %s eats until whitespace, so we
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* replace : by \n so it doesn't get eaten later by
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* strsep */
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colon = strchr(token, ':');
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if (colon != NULL)
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*colon = '\n';
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tokens = sscanf(token, "%s\n%u", submodule, &level);
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if (colon != NULL)
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*colon = ':'; /* set back, for error messages */
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if (tokens == 2)
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d_submodule_set(d_level, d_level_size,
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submodule, level, tag);
|
|
else
|
|
printk(KERN_ERR "%s: can't parse '%s' as a "
|
|
"SUBMODULE:LEVEL (%d tokens)\n",
|
|
tag, token, tokens);
|
|
}
|
|
kfree(params_orig);
|
|
}
|
|
|
|
#endif /* #ifndef __debug__h__ */
|