Add getcontext, setcontext, and swapcontext as system calls.

Previously these were libc functions but were requested to
be made into system calls for atomicity and to coalesce what
might be two entrances into the kernel (signal mask setting
and floating point trap) into one.

A few style nits and comments from bde are also included.

Tested on alpha by: gallatin

4 files changed, 14 insertions, 14 deletions

diff --git a/sys/alpha/include/cpu.h b/sys/alpha/include/cpu.h
index 9d05765..0e39182 100644
--- a/sys/alpha/include/cpu.h
+++ b/sys/alpha/include/cpu.h
@@ -115,11 +115,11 @@ void	XentRestart(void);					/* MAGIC */
 void	XentSys(u_int64_t, u_int64_t, u_int64_t);		/* MAGIC */
 void	XentUna(u_int64_t, u_int64_t, u_int64_t);		/* MAGIC */
 void	alpha_init(u_long, u_long, u_long, u_long, u_long);
+void	alpha_fpstate_check(struct thread *td);
+void	alpha_fpstate_drop(struct thread *td);
+void	alpha_fpstate_save(struct thread *td, int write);
+void	alpha_fpstate_switch(struct thread *td);
 int	alpha_pa_access(u_long);
-void	alpha_fpstate_check(struct thread *p);
-void	alpha_fpstate_save(struct thread *p, int write);
-void	alpha_fpstate_drop(struct thread *p);
-void	alpha_fpstate_switch(struct thread *p);
 int	badaddr	(void *, size_t);
 int	badaddr_read(void *, size_t, void *);
 u_int64_t console_restart(u_int64_t, u_int64_t, u_int64_t);
diff --git a/sys/alpha/include/fpu.h b/sys/alpha/include/fpu.h
index 712a1f9..9f4800f 100644
--- a/sys/alpha/include/fpu.h
+++ b/sys/alpha/include/fpu.h
@@ -116,9 +116,7 @@
 	__asm__("trapb")
 
 #ifdef _KERNEL
-
-extern int fp_software_completion(u_int64_t regmask, struct thread *p);
-
+extern int fp_software_completion(u_int64_t regmask, struct thread *td);
 #endif
 
 #endif /* ! _MACHINE_FPU_H_ */
diff --git a/sys/alpha/include/signal.h b/sys/alpha/include/signal.h
index 2a1f17b..37a969e 100644
--- a/sys/alpha/include/signal.h
+++ b/sys/alpha/include/signal.h
@@ -94,10 +94,9 @@ struct sigcontext {
 	unsigned long sc_fpregs[32];	/* FP register set (see above) */
 	unsigned long sc_fpcr;		/* FP control register (see above) */
 	unsigned long sc_fp_control;	/* FP software control word */
-	long	sc_ownedfp;		/* fp has been used */
-	long	sc_xxx1[2];		/* sc_ssize, sc_sbase on DUX */
-	long	sc_xxx2[3];		/* sc_fp_trap_pc, sc_fp_trigger_sum, sc_fp_trigger_inst */
-	long	sc_reserved[2];		/* XXX */
+	long	sc_ownedfp;		/* fp has been used; see mcontext_t */
+	long	sc_format;		/* see mcontext_t */
+	long	sc_spare[6];		/* XXX */
 };
 
 #define	sc_sp	sc_regs[R_SP]
diff --git a/sys/alpha/include/ucontext.h b/sys/alpha/include/ucontext.h
index bfc18df..2c3ed70 100644
--- a/sys/alpha/include/ucontext.h
+++ b/sys/alpha/include/ucontext.h
@@ -43,11 +43,14 @@ typedef struct __mcontext {
 	unsigned long mc_fpregs[32];
 	unsigned long mc_fpcr;
 	unsigned long mc_fp_control;
+#define	_MC_FPOWNED_NONE	0	/* FP state not used */
+#define	_MC_FPOWNED_FPU		1	/* FP state came from FPU */
+#define	_MC_FPOWNED_PCB		2	/* FP state came from PCB */
 	long	mc_ownedfp;
-#define	__UC_REV0_SIGFRAME	1	/* context is a signal frame */
-#define	__UC_REV0_TRAPFRAME	2	/* context is a trap frame */
+#define	_MC_REV0_SIGFRAME	1	/* context is a signal frame */
+#define	_MC_REV0_TRAPFRAME	2	/* context is a trap frame */
 	long	mc_format;
-	long	__spare__[6];
+	long	mc_spare[6];
 } mcontext_t;
 
 #if defined(_KERNEL) && defined(COMPAT_FREEBSD4)