Add kernel support needed for the KSE-aware libpthread:

	- Maintain fpu state across signals.
	- Save and restore FPU state properly in ucontext_t's.

Reviewed by:	deischen, julian
Approved by:	-arch

4 files changed, 35 insertions, 14 deletions

diff --git a/sys/i386/include/npx.h b/sys/i386/include/npx.h
index 4746f5c..0b66265 100644
--- a/sys/i386/include/npx.h
+++ b/sys/i386/include/npx.h
@@ -73,7 +73,7 @@ struct fpacc87 {
 struct save87 {
 	struct	env87 sv_env;	/* floating point control/status */
 	struct	fpacc87	sv_ac[8];	/* accumulator contents, 0-7 */
-	u_long	sv_ex_sw;	/* status word for last exception */
+	u_char	sv_pad0[4];	/* padding for (now unused) saved status word */
 	/*
 	 * Bogus padding for emulators.  Emulators should use their own
 	 * struct and arrange to store into this struct (ending here)
@@ -112,8 +112,7 @@ struct  savexmm {
 		u_char		fp_pad[6];      /* padding */
 	} sv_fp[8];
 	struct xmmacc	sv_xmm[8];
-	u_long sv_ex_sw;	/* status word for last exception */
-	u_char sv_pad[220];
+	u_char sv_pad[224];
 } __attribute__((aligned(16)));
 
 union	savefpu {
@@ -142,9 +141,13 @@ union	savefpu {
 
 #ifdef _KERNEL
 int	npxdna(void);
+void	npxdrop(void);
 void	npxexit(struct thread *td);
-void	npxinit(int control);
+int	npxformat(void);
+int	npxgetregs(struct thread *td, union savefpu *addr);
+void	npxinit(u_short control);
 void	npxsave(union savefpu *addr);
+void	npxsetregs(struct thread *td, union savefpu *addr);
 int	npxtrap(void);
 #endif
 
diff --git a/sys/i386/include/pcb.h b/sys/i386/include/pcb.h
index 860b3b5..50cff07 100644
--- a/sys/i386/include/pcb.h
+++ b/sys/i386/include/pcb.h
@@ -66,6 +66,7 @@ struct pcb {
 #define	FP_SOFTFP	0x01	/* process using software fltng pnt emulator */
 #define	PCB_DBREGS	0x02	/* process using debug registers */
 #define	PCB_NPXTRAP	0x04	/* npx trap pending */
+#define	PCB_NPXINITDONE	0x08	/* fpu state is initialized */
 	caddr_t	pcb_onfault;	/* copyin/out fault recovery */
 	int	pcb_gs;
 	struct	pcb_ext	*pcb_ext;	/* optional pcb extension */
diff --git a/sys/i386/include/signal.h b/sys/i386/include/signal.h
index 603a14f..bf76791 100644
--- a/sys/i386/include/signal.h
+++ b/sys/i386/include/signal.h
@@ -117,13 +117,16 @@ struct sigcontext {
 	int	sc_efl;
 	int	sc_esp;
 	int	sc_ss;
+	int	sc_len;			/* sizeof(struct mcontext_t) */
 	/*
-	 * XXX FPU state is 27 * 4 bytes h/w, 1 * 4 bytes s/w (probably not
-	 * needed here), or that + 16 * 4 bytes for emulators (probably all
-	 * needed here).  The "spare" bytes are mostly not spare.
+	 * XXX - See <machine/ucontext.h> and <machine/npx.h> for
+	 *       the following fields.
 	 */
-	int	sc_fpregs[28];		/* machine state (FPU): */
-	int	sc_spare[17];
+	int	sc_fpformat;
+	int	sc_ownedfp;
+	int	sc_spare1[1];
+	int	sc_fpregs[128];
+	int	sc_spare2[8];
 };
 
 #define	sc_sp		sc_esp
diff --git a/sys/i386/include/ucontext.h b/sys/i386/include/ucontext.h
index a84a2cb..1739818 100644
--- a/sys/i386/include/ucontext.h
+++ b/sys/i386/include/ucontext.h
@@ -58,11 +58,25 @@ typedef struct __mcontext {
 	int	mc_esp;			/* machine state */
 	int	mc_ss;
 
-	int	mc_fpregs[28];		/* env87 + fpacc87 + u_long */
-#define	__UC_MC_VALID	0x0001		/* mcontext register state is valid */
-#define	__UC_FP_VALID	0x0002		/* FP registers have been saved */
-	int	mc_flags;
-	int	__spare__[16];
+	int	mc_len;			/* sizeof(mcontext_t) */
+#define	_MC_FPFMT_NODEV		0	/* device not present or configured */
+#define	_MC_FPFMT_387		1
+#define	_MC_FPFMT_XMM		2
+	int	mc_fpformat;
+#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 */
+	int	mc_ownedfp;
+	int	mc_spare1[1];		/* align next field to 16 bytes */
+	int	mc_fpstate[128];	/* must be multiple of 16 bytes */
+	int	mc_spare2[8];
 } mcontext_t;
 
+#ifdef _KERNEL
+struct thread;
+
+void	get_mcontext(struct thread *td, mcontext_t *mcp);
+int	set_mcontext(struct thread *td, const mcontext_t *mcp);
+#endif
+
 #endif /* !_MACHINE_UCONTEXT_H_ */