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

4 files changed, 358 insertions, 21 deletions

diff --git a/lib/libkse/arch/i386/Makefile.inc b/lib/libkse/arch/i386/Makefile.inc
index c5cbe18..73a9a8a 100644
--- a/lib/libkse/arch/i386/Makefile.inc
+++ b/lib/libkse/arch/i386/Makefile.inc
@@ -2,4 +2,4 @@
 
 .PATH:	${.CURDIR}/arch/${MACHINE_ARCH}/${MACHINE_ARCH}
 
-SRCS+=	ksd.c thr_enter_uts.S thr_getcontext.S
+SRCS+=	thr_enter_uts.S thr_getcontext.S pthread_md.c
diff --git a/lib/libkse/arch/i386/i386/pthread_md.c b/lib/libkse/arch/i386/i386/pthread_md.c
new file mode 100644
index 0000000..aeaa649
--- /dev/null
+++ b/lib/libkse/arch/i386/i386/pthread_md.c
@@ -0,0 +1,171 @@
+/*-
+ * Copyright (C) 2003 David Xu <davidxu@freebsd.org>
+ * Copyright (c) 2001,2003 Daniel Eischen <deischen@freebsd.org>
+ * 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. Neither the name of the author nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/types.h>
+#include <machine/cpufunc.h>
+#include <machine/segments.h>
+#include <machine/sysarch.h>
+
+#include <unistd.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <ucontext.h>
+
+#include "pthread_md.h"
+
+#define LDT_ENTRIES 8192
+#define LDT_WORDS   (8192/sizeof(unsigned int))
+#define LDT_RESERVED NLDT
+
+static unsigned int ldt_mask[LDT_WORDS];
+static int initialized = 0;
+
+static void	initialize(void);
+
+static void
+initialize(void)
+{
+	int i, j;
+
+	memset(ldt_mask, 0xFF, sizeof(ldt_mask));
+	/* Reserve system predefined LDT entries */
+	for (i = 0; i < LDT_RESERVED; ++i) {
+		j = i / 32;
+		ldt_mask[j] &= ~(1 << (i % 32));
+	}
+	initialized = 1;
+}
+
+static u_int
+alloc_ldt_entry(void)
+{
+	u_int i, j, index;
+	
+	index = 0;
+	for (i = 0; i < LDT_WORDS; ++i) {
+		if (ldt_mask[i] != 0) {
+			j = bsfl(ldt_mask[i]);
+			ldt_mask[i] &= ~(1 << j);
+			index = i * 32 + j;
+			break;
+		}
+	}
+	return (index);
+}
+
+static void
+free_ldt_entry(u_int index)
+{
+	u_int i, j;
+
+	if (index < LDT_RESERVED || index >= LDT_ENTRIES)
+		return;
+	i = index / 32;
+	j = index % 32;
+	ldt_mask[i] |= (1 << j);
+}
+
+struct tcb *
+_tcb_ctor(struct pthread *thread)
+{
+	struct tcb *tcb;
+	void *addr;
+
+	addr = malloc(sizeof(struct tcb) + 15);
+	if (addr == NULL)
+		tcb = NULL;
+	else {
+		tcb = (struct tcb *)(((uintptr_t)(addr) + 15) & ~15);
+		bzero(tcb, sizeof(struct tcb));
+		tcb->tcb_addr = addr;
+		tcb->tcb_thread = thread;
+		/* XXX - Allocate tdv/tls */
+	}
+	return (tcb);
+}
+
+void
+_tcb_dtor(struct tcb *tcb)
+{
+	void *addr;
+
+	addr = tcb->tcb_addr;
+	tcb->tcb_addr = NULL;
+	free(addr);
+}
+
+/*
+ * Initialize KSD.  This also includes setting up the LDT.
+ */
+struct kcb *
+_kcb_ctor(struct kse *kse)
+{
+	union descriptor ldt;
+	struct kcb *kcb;
+
+	if (initialized == 0)
+		initialize();
+	kcb = malloc(sizeof(struct kcb));
+	if (kcb != NULL) {
+		bzero(kcb, sizeof(struct kcb));
+		kcb->kcb_self = kcb;
+		kcb->kcb_kse = kse;
+		kcb->kcb_ldt = alloc_ldt_entry();
+		if (kcb->kcb_ldt == 0) {
+			free(kcb);
+			return (NULL);
+		}
+		ldt.sd.sd_hibase = (unsigned int)kcb >> 24;
+		ldt.sd.sd_lobase = (unsigned int)kcb & 0xFFFFFF;
+		ldt.sd.sd_hilimit = (sizeof(struct kcb) >> 16) & 0xF;
+		ldt.sd.sd_lolimit = sizeof(struct kcb) & 0xFFFF;
+		ldt.sd.sd_type = SDT_MEMRWA;
+		ldt.sd.sd_dpl = SEL_UPL;
+		ldt.sd.sd_p = 1;
+		ldt.sd.sd_xx = 0;
+		ldt.sd.sd_def32 = 1;
+		ldt.sd.sd_gran = 0;	/* no more than 1M */
+		if (i386_set_ldt(kcb->kcb_ldt, &ldt, 1) < 0) {
+			free_ldt_entry(kcb->kcb_ldt);
+			free(kcb);
+			return (NULL);
+		}
+	}
+	return (kcb);
+}
+
+void
+_kcb_dtor(struct kcb *kcb)
+{
+	if (kcb->kcb_ldt != -1)
+		free_ldt_entry(kcb->kcb_ldt);
+	free(kcb);
+}
diff --git a/lib/libkse/arch/i386/i386/thr_getcontext.S b/lib/libkse/arch/i386/i386/thr_getcontext.S
index 19afd06..7f58dce 100644
--- a/lib/libkse/arch/i386/i386/thr_getcontext.S
+++ b/lib/libkse/arch/i386/i386/thr_getcontext.S
@@ -74,7 +74,7 @@ ENTRY(__thr_setcontext)
 	movl	72(%edx), %esp		/* switch to context defined stack */
 	pushl	60(%edx)		/* push return address on stack */
 	pushl	44(%edx)		/* push ecx on stack */
-	push	48(%edx)		/* push eax on stack */
+	pushl	48(%edx)		/* push eax on stack */
 	/*
 	 * if (mc_fpowned == MC_OWNEDFP_FPU || mc_fpowned == MC_OWNEDFP_PCB) {
 	 *    if (mc_fpformat == MC_FPFMT_387)
diff --git a/lib/libkse/arch/i386/include/pthread_md.h b/lib/libkse/arch/i386/include/pthread_md.h
index 980680a..9718562 100644
--- a/lib/libkse/arch/i386/include/pthread_md.h
+++ b/lib/libkse/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);
 }