Rethink the MD interfaces for libpthread to account for

archs that can (or are required to) have per-thread registers.

Tested on i386, amd64; marcel is testing on ia64 and will
have some follow-up commits.

Reviewed by:	davidxu

1 files changed, 185 insertions, 19 deletions

diff --git a/lib/libpthread/arch/i386/include/pthread_md.h b/lib/libpthread/arch/i386/include/pthread_md.h
index 980680a..9718562 100644
--- a/lib/libpthread/arch/i386/include/pthread_md.h
+++ b/lib/libpthread/arch/i386/include/pthread_md.h
@@ -37,34 +37,193 @@
 extern int _thr_setcontext(mcontext_t *, intptr_t, intptr_t *);
 extern int _thr_getcontext(mcontext_t *);
 
-#define	THR_GETCONTEXT(ucp)	_thr_getcontext(&(ucp)->uc_mcontext);
-#define	THR_SETCONTEXT(ucp)	_thr_setcontext(&(ucp)->uc_mcontext, NULL, NULL);
+#define	THR_GETCONTEXT(ucp)	_thr_getcontext(&(ucp)->uc_mcontext)
+#define	THR_SETCONTEXT(ucp)	_thr_setcontext(&(ucp)->uc_mcontext, 0, NULL)
 
-#define	THR_ALIGNBYTES	15
-#define	THR_ALIGN(td)	(((unsigned)(td) + THR_ALIGNBYTES) & ~THR_ALIGNBYTES)
+#define	PER_KSE
+#undef	PER_THREAD
+
+struct kse;
+struct pthread;
+struct tdv;
 
 /*
- * KSE Specific Data.
+ * %gs points to a struct kcb.
  */
-struct ksd {
-	int	ldt;
-#define	KSDF_INITIALIZED	0x01
-	long	flags;
-	void	*base;
-	long	size;
+struct kcb {
+	struct tcb		*kcb_curtcb;
+	struct kcb		*kcb_self;	/* self reference */
+	int			kcb_ldt;
+	struct kse		*kcb_kse;
+	struct kse_mailbox	kcb_kmbx;
+};
+
+struct tcb {
+	struct tdv		*tcb_tdv;
+	struct pthread		*tcb_thread;
+	void			*tcb_addr;	/* allocated tcb address */
+	void			*tcb_spare;	/* align tcb_tmbx to 16 bytes */
+	struct kse_thr_mailbox	tcb_tmbx;
 };
 
-extern void _i386_enter_uts(struct kse_mailbox *, kse_func_t, void *, long);
+/*
+ * Evaluates to the byte offset of the per-kse variable name.
+ */
+#define	__kcb_offset(name)	__offsetof(struct kcb, name)
+
+/*
+ * Evaluates to the type of the per-kse variable name.
+ */
+#define	__kcb_type(name)	__typeof(((struct kcb *)0)->name)
+
+/*
+ * Evaluates to the value of the per-kse variable name.
+ */
+#define	KCB_GET32(name) ({					\
+	__kcb_type(name) __result;				\
+								\
+	u_int __i;						\
+	__asm __volatile("movl %%gs:%1, %0"			\
+	    : "=r" (__i)					\
+	    : "m" (*(u_int *)(__kcb_offset(name))));		\
+	__result = *(__kcb_type(name) *)&__i;			\
+								\
+	__result;						\
+})
+
+/*
+ * Sets the value of the per-kse variable name to value val.
+ */
+#define	KCB_SET32(name, val) ({					\
+	__kcb_type(name) __val = (val);				\
+								\
+	u_int __i;						\
+	__i = *(u_int *)&__val;					\
+	__asm __volatile("movl %1,%%gs:%0"			\
+	    : "=m" (*(u_int *)(__kcb_offset(name)))		\
+	    : "r" (__i));					\
+})
+
+static __inline u_long
+__kcb_readandclear32(volatile u_long *addr)
+{
+	u_long result;
+
+	__asm __volatile (
+	    "	xorl	%0, %0;"
+	    "	xchgl	%%gs:%1, %0;"
+	    "# __kcb_readandclear32"
+	    : "=&r" (result)
+	    : "m" (*addr));
+	return (result);
+}
+
+#define	KCB_READANDCLEAR32(name) ({				\
+	__kcb_type(name) __result;				\
+								\
+	__result = (__kcb_type(name))				\
+	    __kcb_readandclear32((u_long *)__kcb_offset(name)); \
+	__result;						\
+})
+
+
+#define	_kcb_curkcb()		KCB_GET32(kcb_self)
+#define	_kcb_curtcb()		KCB_GET32(kcb_curtcb)
+#define	_kcb_curkse()		((struct kse *)KCB_GET32(kcb_kmbx.km_udata))
+#define	_kcb_get_tmbx()		KCB_GET32(kcb_kmbx.km_curthread)
+#define	_kcb_set_tmbx(value)	KCB_SET32(kcb_kmbx.km_curthread, (void *)value)
+#define	_kcb_readandclear_tmbx() KCB_READANDCLEAR32(kcb_kmbx.km_curthread)
+
+
+/*
+ * The constructors.
+ */
+struct tcb	*_tcb_ctor(struct pthread *);
+void		_tcb_dtor(struct tcb *tcb);
+struct kcb	*_kcb_ctor(struct kse *);
+void		_kcb_dtor(struct kcb *);
+
+/* Called from the KSE to set its private data. */
+static __inline void
+_kcb_set(struct kcb *kcb)
+{
+	int val;
+
+	val = (kcb->kcb_ldt << 3) | 7;
+	__asm __volatile("movl %0, %%gs" : : "r" (val));
+}
+
+/* Get the current kcb. */
+static __inline struct kcb *
+_kcb_get(void)
+{
+	return (_kcb_curkcb());
+}
+
+static __inline struct kse_thr_mailbox *
+_kcb_critical_enter(void)
+{
+	struct kse_thr_mailbox *crit;
+
+	crit = _kcb_readandclear_tmbx();
+	return (crit);
+}
+
+static __inline void
+_kcb_critical_leave(struct kse_thr_mailbox *crit)
+{
+	_kcb_set_tmbx(crit);
+}
 
 static __inline int
-_thread_enter_uts(struct kse_thr_mailbox *tmbx, struct kse_mailbox *kmbx)
+_kcb_in_critical(void)
+{
+	return (_kcb_get_tmbx() == NULL);
+}
+
+static __inline void
+_tcb_set(struct kcb *kcb, struct tcb *tcb)
+{
+	kcb->kcb_curtcb = tcb;
+}
+
+static __inline struct tcb *
+_tcb_get(void)
+{
+	return (_kcb_curtcb());
+}
+
+static __inline struct pthread *
+_get_curthread(void)
+{
+	struct tcb *tcb;
+
+	tcb = _kcb_curtcb();
+	if (tcb != NULL)
+		return (tcb->tcb_thread);
+	else
+		return (NULL);
+}
+
+static __inline struct kse *
+_get_curkse(void)
+{
+	return ((struct kse *)_kcb_curkse());
+}
+
+void	_i386_enter_uts(struct kse_mailbox *km, kse_func_t uts, void *stack,
+    size_t stacksz);
+
+static __inline int
+_thread_enter_uts(struct tcb *tcb, struct kcb *kcb)
 {
 	int ret;
 
-	ret = _thr_getcontext(&tmbx->tm_context.uc_mcontext);
+	ret = _thr_getcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext);
 	if (ret == 0) {
-		_i386_enter_uts(kmbx, kmbx->km_func,
-		    kmbx->km_stack.ss_sp, kmbx->km_stack.ss_size);
+		_i386_enter_uts(&kcb->kcb_kmbx, kcb->kcb_kmbx.km_func,
+		    kcb->kcb_kmbx.km_stack.ss_sp,
+		    kcb->kcb_kmbx.km_stack.ss_size);
 		/* We should not reach here. */
 		return (-1);
 	}
@@ -74,10 +233,17 @@ _thread_enter_uts(struct kse_thr_mailbox *tmbx, struct kse_mailbox *kmbx)
 }
 
 static __inline int
-_thread_switch(struct kse_thr_mailbox *tmbx, struct kse_thr_mailbox **loc)
+_thread_switch(struct kcb *kcb, struct tcb *tcb, int setmbox)
 {
-	_thr_setcontext(&tmbx->tm_context.uc_mcontext,
-	    (intptr_t)tmbx, (intptr_t *)loc);
+	if ((kcb == NULL) || (tcb == NULL))
+		return (-1);
+	kcb->kcb_curtcb = tcb;
+	if (setmbox != 0)
+		_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
+		    (intptr_t)&tcb->tcb_tmbx,
+		    (intptr_t *)&kcb->kcb_kmbx.km_curthread);
+	else
+		_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext, 0, NULL);
 	/* We should not reach here. */
 	return (-1);
 }