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-rw-r--r--sys/alpha/include/mutex.h563
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diff --git a/sys/alpha/include/mutex.h b/sys/alpha/include/mutex.h
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+/*-
+ * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Berkeley Software Design Inc's name may not be used to endorse or
+ * promote products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * from BSDI $Id: mutex.h,v 2.7.2.35 2000/04/27 03:10:26 cp Exp $
+ * $FreeBSD$
+ */
+
+
+#ifndef _MACHINE_MUTEX_H_
+#define _MACHINE_MUTEX_H_
+
+#ifndef LOCORE
+
+#include <sys/queue.h>
+#include <machine/atomic.h>
+#include <machine/cpufunc.h>
+#include <machine/globaldata.h>
+
+/*
+ * Mutex flags
+ *
+ * Types
+ */
+#define MTX_DEF 0x1 /* Default (spin/sleep) */
+#define MTX_SPIN 0x2 /* Spin only lock */
+
+/* Options */
+#define MTX_RLIKELY 0x4 /* (opt) Recursion likely */
+#define MTX_NORECURSE 0x8 /* No recursion possible */
+#define MTX_NOSPIN 0x10 /* Don't spin before sleeping */
+#define MTX_NOSWITCH 0x20 /* Do not switch on release */
+#define MTX_FIRST 0x40 /* First spin lock holder */
+#define MTX_TOPHALF 0x80 /* Interrupts not disabled on spin */
+
+/* options that should be passed on to mtx_enter_hard, mtx_exit_hard */
+#define MTX_HARDOPTS (MTX_DEF | MTX_SPIN | MTX_FIRST | MTX_TOPHALF | MTX_NOSWITCH)
+
+/* Flags/value used in mtx_lock */
+#define MTX_RECURSE 0x01 /* (non-spin) lock held recursively */
+#define MTX_CONTESTED 0x02 /* (non-spin) lock contested */
+#define MTX_FLAGMASK ~(MTX_RECURSE | MTX_CONTESTED)
+#define MTX_UNOWNED 0x8 /* Cookie for free mutex */
+
+struct proc; /* XXX */
+
+/*
+ * Sleep/spin mutex
+ */
+struct mtx {
+ volatile u_int64_t mtx_lock; /* lock owner/gate/flags */
+ volatile u_int32_t mtx_recurse; /* number of recursive holds */
+ u_int32_t mtx_saveipl; /* saved ipl (for spin locks) */
+ char *mtx_description;
+ TAILQ_HEAD(, proc) mtx_blocked;
+ LIST_ENTRY(mtx) mtx_contested;
+ struct mtx *mtx_next; /* all locks in system */
+ struct mtx *mtx_prev;
+#ifdef SMP_DEBUG
+ /* If you add anything here, adjust the mtxf_t definition below */
+ struct witness *mtx_witness;
+ LIST_ENTRY(mtx) mtx_held;
+ char *mtx_file;
+ int mtx_line;
+#endif /* SMP_DEBUG */
+};
+
+typedef struct mtx mtx_t;
+
+/*
+ * Filler for structs which need to remain the same size
+ * whether or not SMP_DEBUG is turned on.
+ */
+typedef struct mtxf {
+#ifdef SMP_DEBUG
+ char mtxf_data[0];
+#else
+ char mtxf_data[4*sizeof(void *) + sizeof(int)];
+#endif
+} mtxf_t;
+
+#define mp_fixme(string)
+
+#ifdef _KERNEL
+/* Misc */
+#define CURTHD ((u_int64_t)CURPROC) /* Current thread ID */
+
+/* Prototypes */
+void mtx_init(mtx_t *m, char *description, int flag);
+void mtx_enter_hard(mtx_t *, int type, int ipl);
+void mtx_exit_hard(mtx_t *, int type);
+void mtx_destroy(mtx_t *m);
+
+/* Global locks */
+extern mtx_t sched_lock;
+extern mtx_t Giant;
+
+/*
+ * Used to replace return with an exit Giant and return.
+ */
+
+#define EGAR(a) \
+do { \
+ mtx_exit(&Giant, MTX_DEF); \
+ return (a); \
+} while (0)
+
+#define VEGAR \
+do { \
+ mtx_exit(&Giant, MTX_DEF); \
+ return; \
+} while (0)
+
+#define DROP_GIANT() \
+do { \
+ int _giantcnt; \
+ WITNESS_SAVE_DECL(Giant); \
+ \
+ WITNESS_SAVE(&Giant, Giant); \
+ for (_giantcnt = 0; mtx_owned(&Giant); _giantcnt++) \
+ mtx_exit(&Giant, MTX_DEF)
+
+#define PICKUP_GIANT() \
+ mtx_assert(&Giant, MA_NOTOWNED); \
+ while (_giantcnt--) \
+ mtx_enter(&Giant, MTX_DEF); \
+ WITNESS_RESTORE(&Giant, Giant); \
+} while (0)
+
+#define PARTIAL_PICKUP_GIANT() \
+ mtx_assert(&Giant, MA_NOTOWNED); \
+ while (_giantcnt--) \
+ mtx_enter(&Giant, MTX_DEF); \
+ WITNESS_RESTORE(&Giant, Giant)
+
+
+/*
+ * Debugging
+ */
+#ifndef SMP_DEBUG
+#define mtx_assert(m, what)
+#else /* SMP_DEBUG */
+
+#define MA_OWNED 1
+#define MA_NOTOWNED 2
+#define mtx_assert(m, what) { \
+ switch ((what)) { \
+ case MA_OWNED: \
+ ASS(mtx_owned((m))); \
+ break; \
+ case MA_NOTOWNED: \
+ ASS(!mtx_owned((m))); \
+ break; \
+ default: \
+ panic("unknown mtx_assert at %s:%d", __FILE__, __LINE__); \
+ } \
+}
+
+#ifdef INVARIANTS
+#define ASS(ex) MPASS(ex)
+#define MPASS(ex) if (!(ex)) panic("Assertion %s failed at %s:%d", \
+ #ex, __FILE__, __LINE__)
+#define MPASS2(ex, what) if (!(ex)) panic("Assertion %s failed at %s:%d", \
+ what, __FILE__, __LINE__)
+
+#ifdef MTX_STRS
+char STR_IEN[] = "fl & 0x200";
+char STR_IDIS[] = "!(fl & 0x200)";
+#else /* MTX_STRS */
+extern char STR_IEN[];
+extern char STR_IDIS[];
+#endif /* MTX_STRS */
+#define ASS_IEN MPASS2((alpha_pal_rdps & ALPHA_PSL_IPL_MASK)
+ == ALPHA_PSL_IPL_HIGH, STR_IEN)
+#define ASS_IDIS MPASS2((alpha_pal_rdps & ALPHA_PSL_IPL_MASK)
+ != ALPHA_PSL_IPL_HIGH, STR_IDIS)
+#endif /* INVARIANTS */
+
+#endif /* SMP_DEBUG */
+
+#if !defined(SMP_DEBUG) || !defined(INVARIANTS)
+#define ASS(ex)
+#define MPASS(ex)
+#define MPASS2(ex, where)
+#define ASS_IEN
+#define ASS_IDIS
+#endif /* !defined(SMP_DEBUG) || !defined(INVARIANTS) */
+
+#ifdef WITNESS
+#ifndef SMP_DEBUG
+#error WITNESS requires SMP_DEBUG
+#endif /* SMP_DEBUG */
+#define WITNESS_ENTER(m, f) \
+ if ((m)->mtx_witness != NULL) \
+ witness_enter((m), (f), __FILE__, __LINE__)
+#define WITNESS_EXIT(m, f) \
+ if ((m)->mtx_witness != NULL) \
+ witness_exit((m), (f), __FILE__, __LINE__)
+
+#define WITNESS_SLEEP(check, m) witness_sleep(check, (m), __FILE__, __LINE__)
+#define WITNESS_SAVE_DECL(n) \
+ char * __CONCAT(n, __wf); \
+ int __CONCAT(n, __wl)
+
+#define WITNESS_SAVE(m, n) \
+do { \
+ if ((m)->mtx_witness != NULL) \
+ witness_save(m, &__CONCAT(n, __wf), &__CONCAT(n, __wl)); \
+} while (0)
+
+#define WITNESS_RESTORE(m, n) \
+do { \
+ if ((m)->mtx_witness != NULL) \
+ witness_restore(m, __CONCAT(n, __wf), __CONCAT(n, __wl)); \
+} while (0)
+
+void witness_init(mtx_t *, int flag);
+void witness_destroy(mtx_t *);
+void witness_enter(mtx_t *, int, char *, int);
+void witness_try_enter(mtx_t *, int, char *, int);
+void witness_exit(mtx_t *, int, char *, int);
+void witness_display(void(*)(const char *fmt, ...));
+void witness_list(struct proc *);
+int witness_sleep(int, mtx_t *, char *, int);
+void witness_save(mtx_t *, char **, int *);
+void witness_restore(mtx_t *, char *, int);
+#else /* WITNESS */
+#define WITNESS_ENTER(m, flag)
+#define WITNESS_EXIT(m, flag)
+#define WITNESS_SLEEP(check, m)
+#define WITNESS_SAVE_DECL(n)
+#define WITNESS_SAVE(m, n)
+#define WITNESS_RESTORE(m, n)
+
+/*
+ * flag++ is slezoid way of shutting up unused parameter warning
+ * in mtx_init()
+ */
+#define witness_init(m, flag) flag++
+#define witness_destroy(m)
+#define witness_enter(m, flag, f, l)
+#define witness_try_enter(m, flag, f, l )
+#define witness_exit(m, flag, f, l)
+#endif /* WITNESS */
+
+/*
+ * Assembly macros (for internal use only)
+ *--------------------------------------------------------------------------
+ */
+
+/*
+ * Get a sleep lock, deal with recursion inline
+ */
+
+#define _V(x) __STRING(x)
+
+#define _getlock_sleep(mp, tid, type) do { \
+ if (atomic_cmpset_64(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) == 0) { \
+ if (((mp)->mtx_lock & MTX_FLAGMASK) != (tid)) \
+ mtx_enter_hard(mp, (type) & MTX_HARDOPTS, 0); \
+ else { \
+ if (((mp)->mtx_lock & MTX_RECURSE) == 0) \
+ atomic_set_64(&(mp)->mtx_lock, MTX_RECURSE); \
+ (mp)->mtx_recurse++; \
+ } \
+ } else { \
+ alpha_mb(); \
+ } \
+} while (0)
+
+/*
+ * Get a spin lock, handle recusion inline (as the less common case)
+ */
+
+#define _getlock_spin_block(mp, tid, type) do { \
+ u_int _ipl = alpha_pal_rdps() & ALPHA_PSL_IPL_MASK; \
+ if (atomic_cmpset_64(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) == 0) \
+ mtx_enter_hard(mp, (type) & MTX_HARDOPTS, _ipl); \
+ else { \
+ alpha_mb(); \
+ (mp)->mtx_saveipl = _ipl; \
+ } \
+} while (0)
+
+/*
+ * Get a lock without any recursion handling. Calls the hard enter
+ * function if we can't get it inline.
+ */
+
+#define _getlock_norecurse(mp, tid, type) do { \
+ if (atomic_cmpset_64(&(mp)->mtx_lock, MTX_UNOWNED, (tid)) == 0) \
+ mtx_enter_hard((mp), (type) & MTX_HARDOPTS, 0); \
+ else \
+ alpha_mb(); \
+} while (0)
+
+/*
+ * Release a sleep lock assuming we haven't recursed on it, recursion is
+ * handled in the hard function.
+ */
+
+#define _exitlock_norecurse(mp, tid, type) do { \
+ alpha_mb(); \
+ if (atomic_cmpset_64(&(mp)->mtx_lock, (tid), MTX_UNOWNED) == 0) \
+ mtx_exit_hard((mp), (type) & MTX_HARDOPTS); \
+} while (0)
+
+/*
+ * Release a sleep lock when its likely we recursed (the code to
+ * deal with simple recursion is inline).
+ */
+
+#define _exitlock(mp, tid, type) do { \
+ alpha_mb(); \
+ if (atomic_cmpset_64(&(mp)->mtx_lock, (tid), MTX_UNOWNED) == 0) {\
+ if (((mp)->mtx_lock & MTX_RECURSE) && \
+ (--(mp)->mtx_recurse == 0)) \
+ atomic_clear_64(&(mp)->mtx_lock, MTX_RECURSE); \
+ else \
+ mtx_exit_hard((mp), (type) & MTX_HARDOPTS); \
+ } \
+} while (0)
+
+/*
+ * Release a spin lock (with possible recursion)
+ */
+
+#define _exitlock_spin(mp) do { \
+ int _ipl = (mp)->mtx_saveipl; \
+ alpha_mb(); \
+ if ((mp)->mtx_recurse == 0 || (--(mp)->mtx_recurse) == 0) \
+ atomic_cmpset_64(&(mp)->mtx_lock, (mp)->mtx_lock, \
+ MTX_UNOWNED); \
+ alpha_pal_swpipl(_ipl); \
+} while (0)
+
+/*
+ * Externally visible mutex functions
+ *------------------------------------------------------------------------
+ */
+
+/*
+ * Return non-zero if a mutex is already owned by the current thread
+ */
+#define mtx_owned(m) (((m)->mtx_lock & MTX_FLAGMASK) == CURTHD)
+
+/* Common strings */
+#ifdef MTX_STRS
+char STR_mtx_enter_fmt[] = "GOT %s [%p] at %s:%d r=%d";
+char STR_mtx_bad_type[] = "((type) & (MTX_NORECURSE | MTX_NOSWITCH)) == 0";
+char STR_mtx_exit_fmt[] = "REL %s [%p] at %s:%d r=%d";
+char STR_mtx_owned[] = "mtx_owned(_mpp)";
+char STR_mtx_recurse[] = "_mpp->mtx_recurse == 0";
+char STR_mtx_try_enter_fmt[] = "TRY_ENTER %s [%p] at %s:%d result=%d";
+#else /* MTX_STRS */
+extern char STR_mtx_enter_fmt[];
+extern char STR_mtx_bad_type[];
+extern char STR_mtx_exit_fmt[];
+extern char STR_mtx_owned[];
+extern char STR_mtx_recurse[];
+extern char STR_mtx_try_enter_fmt[];
+#endif /* MTX_STRS */
+
+/*
+ * Get lock 'm', the macro handles the easy (and most common cases) and
+ * leaves the slow stuff to the mtx_enter_hard() function.
+ *
+ * Note: since type is usually a constant much of this code is optimized out
+ */
+#define mtx_enter(mtxp, type) do { \
+ mtx_t * _mpp = mtxp; \
+ \
+ /* bits only valid on mtx_exit() */ \
+ MPASS2(((type) & (MTX_NORECURSE | MTX_NOSWITCH)) == 0, STR_mtx_bad_type); \
+ \
+ do { \
+ if ((type) & MTX_SPIN) { \
+ /* \
+ * Easy cases of spin locks: \
+ * \
+ * 1) We already own the lock and will simply \
+ * recurse on it (if RLIKELY) \
+ * \
+ * 2) The lock is free, we just get it \
+ */ \
+ if ((type) & MTX_RLIKELY) { \
+ /* \
+ * Check for recursion, if we already \
+ * have this lock we just bump the \
+ * recursion count. \
+ */ \
+ if (_mpp->mtx_lock == CURTHD) { \
+ _mpp->mtx_recurse++; \
+ break; /* Done */ \
+ } \
+ } \
+ \
+ if (((type) & MTX_TOPHALF) == 0) \
+ /* \
+ * If an interrupt thread uses this \
+ * we must block interrupts here. \
+ */ \
+ _getlock_spin_block(_mpp, CURTHD, \
+ (type) & MTX_HARDOPTS); \
+ else \
+ _getlock_norecurse(_mpp, CURTHD, \
+ (type) & MTX_HARDOPTS); \
+ } else { \
+ /* Sleep locks */ \
+ if ((type) & MTX_RLIKELY) \
+ _getlock_sleep(_mpp, CURTHD, \
+ (type) & MTX_HARDOPTS); \
+ else \
+ _getlock_norecurse(_mpp, CURTHD, \
+ (type) & MTX_HARDOPTS); \
+ } \
+ } while (0); \
+ WITNESS_ENTER(_mpp, type); \
+ CTR5(KTR_LOCK, STR_mtx_enter_fmt, \
+ (_mpp)->mtx_description, (_mpp), __FILE__, __LINE__, \
+ (_mpp)->mtx_recurse); \
+} while (0)
+
+/*
+ * Attempt to get MTX_DEF lock, return non-zero if lock acquired
+ *
+ * XXX DOES NOT HANDLE RECURSION
+ */
+#ifdef SMP_DEBUG
+#define mtx_try_enter(mtxp, type) ({ \
+ mtx_t *const _mpp = mtxp; \
+ int _rval; \
+ \
+ _rval = atomic_cmpset_int(&_mpp->mtx_lock, MTX_UNOWNED, CURTHD);\
+ if (_rval && (_mpp)->mtx_witness != NULL) { \
+ ASS((_mpp)->mtx_recurse == 0); \
+ witness_try_enter(_mpp, type, __FILE__, __LINE__); \
+ } \
+ CTR5(KTR_LOCK, STR_mtx_try_enter_fmt, \
+ (_mpp)->mtx_description, (_mpp), __FILE__, __LINE__, \
+ _rval); \
+ _rval; \
+})
+
+#else /* SMP_DEBUG */
+
+#define mtx_try_enter(mtxp, type) ({ \
+ mtx_t *const _mpp = mtxp; \
+ int _rval; \
+ \
+ _rval = atomic_cmpset_int(&_mpp->mtx_lock, MTX_UNOWNED, CURTHD);\
+ CTR5(KTR_LOCK, STR_mtx_try_enter_fmt, \
+ (_mpp)->mtx_description, (_mpp), __FILE__, __LINE__, \
+ _rval); \
+ _rval; \
+})
+
+#endif /* SMP_DEBUG */
+
+#if 0
+#define mtx_legal2block() ({ \
+ register int _l2b; \
+ __asm __volatile ( \
+" pushfl;" \
+" popl %%eax;" \
+" andl $0x200, %%eax;" \
+ : "=a" (_l2b) \
+ : \
+ : "cc"); \
+ _l2b; \
+})
+#endif
+
+#define mtx_legal2block() (read_eflags() & 0x200)
+
+/*
+ * Release lock m
+ */
+#define mtx_exit(mtxp, type) do { \
+ mtx_t *const _mpp = mtxp; \
+ \
+ MPASS2(mtx_owned(_mpp), STR_mtx_owned); \
+ WITNESS_EXIT(_mpp, type); \
+ CTR5(KTR_LOCK, STR_mtx_exit_fmt, \
+ (_mpp)->mtx_description, (_mpp), __FILE__, __LINE__, \
+ (_mpp)->mtx_recurse); \
+ if ((type) & MTX_SPIN) { \
+ if ((type) & MTX_NORECURSE) { \
+ MPASS2(_mpp->mtx_recurse == 0, STR_mtx_recurse); \
+ atomic_cmpset_64(&_mpp->mtx_lock, _mpp->mtx_lock, \
+ MTX_UNOWNED); \
+ if (((type) & MTX_TOPHALF) == 0) { \
+ splx(_mpp->mtx_saveipl); \
+ } \
+ } else \
+ if ((type) & MTX_TOPHALF) \
+ _exitlock_norecurse(_mpp, CURTHD, \
+ (type) & MTX_HARDOPTS); \
+ else \
+ _exitlock_spin(_mpp); \
+ } else { \
+ /* Handle sleep locks */ \
+ if ((type) & MTX_RLIKELY) \
+ _exitlock(_mpp, CURTHD, (type) & MTX_HARDOPTS); \
+ else \
+ _exitlock_norecurse(_mpp, CURTHD, \
+ (type) & MTX_HARDOPTS); \
+ } \
+} while (0)
+#endif /* _KERNEL */
+
+#else /* !LOCORE */
+
+/*
+ * Simple assembly macros to get and release non-recursive spin locks
+ */
+#define MTX_ENTER(lck) \
+ call_pal PAL_OSF1_rdps; \
+ and v0, ALPHA_PSL_IPL_MASK, v0; \
+1: ldq_l a0, lck+MTX_LOCK; \
+ cmpeq a0, MTX_UNOWNED, a1; \
+ beq a1, 1b; \
+ ldq a0, PC_CURPROC(globalp); \
+ stq_c a0, lck+MTX_LOCK; \
+ beq a0, 1b; \
+ mb; \
+ stl v0, lck+MTX_SAVEIPL; \
+ ldq a0, ALPHA_PSL_IPL_HIGH; \
+ call_pal PSL_OSF1_swpipl
+
+#define MTX_EXIT(lck) \
+ mb; \
+ ldiq a0, MTX_UNOWNED; \
+ stq a0, lck+MTX_LOCK; \
+ ldl a0, lck+MTX_SAVEIPL; \
+ call_pal PAL_OSF1_swpipl
+
+#endif /* !LOCORE */
+
+#endif /* __MACHINE_MUTEX_H */
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