PERFORCE change 49012 for review

[Juli Mallett]

http://perforce.freebsd.org/chv.cgi?CH=49012

Change 49012 by jmallett at jmallett_oingo on 2004/03/15 00:00:18

	Put the stack pointer in the trapframe.

Affected files ...

.. //depot/projects/mips/sys/mips/include/cpu.h#16 edit
.. //depot/projects/mips/sys/mips/include/frame.h#4 edit
.. //depot/projects/mips/sys/mips/mips/exception.S#23 edit
.. //depot/projects/mips/sys/mips/mips/genassym.c#11 edit

Differences ...

==== //depot/projects/mips/sys/mips/include/cpu.h#16 (text+ko) ====

@@ -47,13 +47,8 @@
 #define TRAPF_PC(tframe)	((tframe)->tf_regs[TF_EPC])
 #define	TRAPF_USERMODE(tframe)	((tframe)->tf_regs[TF_SR] & MIPS_SR_KSU_USER)
 
-#if notyet /* XXX */
 #define	cpu_getstack(p)		((p)->td_frame->tf_regs[TF_SP])
 #define	cpu_setstack(p,sp)	((p)->td_frame->tf_regs[TF_SP] = (sp))
-#else
-#define	cpu_getstack(p)		(0)
-#define	cpu_setstack(p,sp)	(0)
-#endif
 
 /*
  * Arrange to handle pending profiling ticks before returning to user mode.

==== //depot/projects/mips/sys/mips/include/frame.h#4 (text+ko) ====

@@ -65,7 +65,9 @@
 #define	TF_MULHI	20
 #define	TF_EPC		21		/* may be changed by trap() call */
 
-#define	TF_NREGS	22
+#define	TF_SP		22
+
+#define	TF_NREGS	23
 
 struct trapframe {
 	__register_t	tf_regs[TF_NREGS];

==== //depot/projects/mips/sys/mips/mips/exception.S#23 (text+ko) ====

@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $P4: //depot/projects/mips/sys/mips/mips/exception.S#22 $
+ * $P4: //depot/projects/mips/sys/mips/mips/exception.S#23 $
  */
 
 #include "opt_ddb.h"
@@ -316,6 +316,12 @@
 	ld	v0, TF_REG_V0(k1)
 
 	/*
+	 * Restore the stack minus TF_SIZE, to account for sp twiddle.
+	 */
+	ld	sp, TF_REG_SP(k1)
+	dsubu	sp, TF_SIZE
+
+	/*
 	 * We are done with the assembler temporary, restore it, and
 	 * return with it disabled, just in case.
 	 */
@@ -379,6 +385,16 @@
 	sd	a1, TF_REG_EPC(k1)
 
 	/*
+	 * When restore returns, TF_SIZE gets added to the SP for
+	 * return.  So in restore, we subtract TF_SIZE, which means
+	 * the value stored herein will be the value returned to.
+	 * To accomodate this, we add TF_SIZE, which makes up for the
+	 * initial subtraction for the trapframe.
+	 */
+	daddu	t0, sp, TF_SIZE
+	sd	t0, TF_REG_SP(k1)
+
+	/*
 	 * All done.
 	 */
 	jr	k0

==== //depot/projects/mips/sys/mips/mips/genassym.c#11 (text+ko) ====

@@ -163,6 +163,7 @@
 ASSYM(TF_REG_MULLO, offsetof(struct trapframe, tf_regs[TF_MULLO]));
 ASSYM(TF_REG_MULHI, offsetof(struct trapframe, tf_regs[TF_MULHI]));
 ASSYM(TF_REG_EPC, offsetof(struct trapframe, tf_regs[TF_EPC]));
+ASSYM(TF_REG_SP, offsetof(struct trapframe, tf_regs[TF_SP]));
 ASSYM(TF_PPL, offsetof(struct trapframe, tf_ppl));
 
 ASSYM(CTXSWFRAME_SIZ, sizeof(label_t));