Date: Thu, 9 Mar 2017 17:01:00 +0000 (UTC) From: Hans Petter Selasky <hselasky@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r314965 - head/sys/compat/linuxkpi/common/include/linux Message-ID: <201703091701.v29H103o051559@repo.freebsd.org>
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Author: hselasky Date: Thu Mar 9 17:01:00 2017 New Revision: 314965 URL: https://svnweb.freebsd.org/changeset/base/314965 Log: Cleanup the LinuxKPI mutex wrappers. Add support for using mutexes during KDB and shutdown. This is also required for doing mode-switching during panic for drm-next. Add new mutex functions mutex_init_witness() and mutex_destroy() allowing LinuxKPI mutexes to be tracked by witness. Declare mutex_is_locked() and mutex_is_owned() like inline functions to get cleaner warnings. These functions are used inside WARN_ON() statements which might look a bit odd if these functions get fully expanded. Give mutexes better debug names through the mutex_name() macro when WITNESS_ALL is defined. The mutex_name() macro can prefix parts of the filename and line number before the mutex name. MFC after: 1 week Sponsored by: Mellanox Technologies Modified: head/sys/compat/linuxkpi/common/include/linux/mutex.h Modified: head/sys/compat/linuxkpi/common/include/linux/mutex.h ============================================================================== --- head/sys/compat/linuxkpi/common/include/linux/mutex.h Thu Mar 9 16:34:55 2017 (r314964) +++ head/sys/compat/linuxkpi/common/include/linux/mutex.h Thu Mar 9 17:01:00 2017 (r314965) @@ -2,7 +2,7 @@ * Copyright (c) 2010 Isilon Systems, Inc. * Copyright (c) 2010 iX Systems, Inc. * Copyright (c) 2010 Panasas, Inc. - * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. + * Copyright (c) 2013-2017 Mellanox Technologies, Ltd. * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -32,6 +32,7 @@ #define _LINUX_MUTEX_H_ #include <sys/param.h> +#include <sys/proc.h> #include <sys/lock.h> #include <sys/sx.h> @@ -41,24 +42,90 @@ typedef struct mutex { struct sx sx; } mutex_t; -#define mutex_lock(_m) sx_xlock(&(_m)->sx) +/* + * By defining CONFIG_NO_MUTEX_SKIP LinuxKPI mutexes and asserts will + * not be skipped during panic(). + */ +#ifdef CONFIG_NO_MUTEX_SKIP +#define MUTEX_SKIP(void) 0 +#else +#define MUTEX_SKIP(void) unlikely(SCHEDULER_STOPPED() || kdb_active) +#endif + +#define mutex_lock(_m) do { \ + if (MUTEX_SKIP()) \ + break; \ + sx_xlock(&(_m)->sx); \ +} while (0) + #define mutex_lock_nested(_m, _s) mutex_lock(_m) -#define mutex_lock_interruptible(_m) ({ mutex_lock((_m)); 0; }) -#define mutex_unlock(_m) sx_xunlock(&(_m)->sx) -#define mutex_trylock(_m) !!sx_try_xlock(&(_m)->sx) +#define mutex_lock_nest_lock(_m, _s) mutex_lock(_m) + +#define mutex_lock_interruptible(_m) ({ \ + MUTEX_SKIP() ? 0 : \ + (sx_xlock_sig(&(_m)->sx) ? -EINTR : 0); \ +}) + +#define mutex_unlock(_m) do { \ + if (MUTEX_SKIP()) \ + break; \ + sx_xunlock(&(_m)->sx); \ +} while (0) + +#define mutex_trylock(_m) ({ \ + MUTEX_SKIP() ? 1 : \ + !!sx_try_xlock(&(_m)->sx); \ +}) + +#define mutex_init(_m) \ + linux_mutex_init(_m, mutex_name(#_m), SX_NOWITNESS) + +#define mutex_init_witness(_m) \ + linux_mutex_init(_m, mutex_name(#_m), SX_DUPOK) + +#define mutex_destroy(_m) \ + linux_mutex_destroy(_m) + +static inline bool +mutex_is_locked(mutex_t *m) +{ + return ((struct thread *)SX_OWNER(m->sx.sx_lock) != NULL); +} -#define DEFINE_MUTEX(lock) \ +static inline bool +mutex_is_owned(mutex_t *m) +{ + return (sx_xlocked(&m->sx)); +} + +#ifdef WITNESS_ALL +/* NOTE: the maximum WITNESS name is 64 chars */ +#define __mutex_name(name, file, line) \ + (((const char *){file ":" #line "-" name}) + \ + (sizeof(file) > 16 ? sizeof(file) - 16 : 0)) +#else +#define __mutex_name(name, file, line) name +#endif +#define _mutex_name(...) __mutex_name(__VA_ARGS__) +#define mutex_name(name) _mutex_name(name, __FILE__, __LINE__) + +#define DEFINE_MUTEX(lock) \ mutex_t lock; \ - SX_SYSINIT_FLAGS(lock, &(lock).sx, "lnxmtx", SX_NOWITNESS) + SX_SYSINIT_FLAGS(lock, &(lock).sx, mutex_name(#lock), SX_DUPOK) static inline void -linux_mutex_init(mutex_t *m) +linux_mutex_init(mutex_t *m, const char *name, int flags) { - - memset(&m->sx, 0, sizeof(m->sx)); - sx_init_flags(&m->sx, "lnxmtx", SX_NOWITNESS); + memset(m, 0, sizeof(*m)); + sx_init_flags(&m->sx, name, flags); } -#define mutex_init(m) linux_mutex_init(m) +static inline void +linux_mutex_destroy(mutex_t *m) +{ + if (mutex_is_owned(m)) + mutex_unlock(m); + sx_destroy(&m->sx); +} -#endif /* _LINUX_MUTEX_H_ */ +#endif /* _LINUX_MUTEX_H_ */
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