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2001-05-07 Joel Sherrill <joel@OARcorp.com>

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* cpu_asm.S: Merged patches from Gregory Menke
	<Gregory.D.Menke.1@gsfc.nasa.gov> that clean up
	stack usage and include nops in the delay slots.
This commit is contained in:
Joel Sherrill
2001-05-07 13:06:56 +00:00
parent 65e6b542fa
commit c556d0bacc
4 changed files with 190 additions and 134 deletions
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6
c/src/exec/score/cpu/mips/ChangeLog
View File

@@ -1,3 +1,9 @@
2001-05-07 Joel Sherrill <joel@OARcorp.com>
* cpu_asm.S: Merged patches from Gregory Menke
<Gregory.D.Menke.1@gsfc.nasa.gov> that clean up
stack usage and include nops in the delay slots.
2001-04-20 Joel Sherrill <joel@OARcorp.com>
* cpu_asm.S: Added code to save and restore SR and EPC to

156
c/src/exec/score/cpu/mips/cpu_asm.S
View File

@@ -38,48 +38,50 @@
#include "iregdef.h"
#include "idtcpu.h"
#define EXCP_STACK_SIZE (NREGS*R_SZ)
#define ISR_VEC_SIZE 4
/* Ifdefs prevent the duplication of code for MIPS ISA Level 3 ( R4xxx )
* and MIPS ISA Level 1 (R3xxx).
*/
#if __mips == 3
/* 64 bit register operations */
#define ADD dadd
#define STREG sd
#define LDREG ld
#define MFCO dmfc0
#define MTCO dmtc0
#define ADDU addu
#define ADDIU addiu
#define R_SZ 8
#define F_SZ 8
#define SZ_INT 8
#define NOP
#define ADD dadd
#define STREG sd
#define LDREG ld
#define MFCO dmfc0
#define MTCO dmtc0
#define ADDU addu
#define ADDIU addiu
#define R_SZ 8
#define F_SZ 8
#define SZ_INT 8
#define SZ_INT_POW2 3
/* XXX if we don't always want 64 bit register ops, then another ifdef */
#elif __mips == 1
/* 32 bit register operations*/
#define ADD add
#define STREG sw
#define LDREG lw
#define MFCO mfc0
#define MTCO mtc0
#define ADDU add
#define ADDIU addi
#define R_SZ 4
#define F_SZ 4
#define SZ_INT 4
#define NOP nop
#define ADD add
#define STREG sw
#define LDREG lw
#define MFCO mfc0
#define MTCO mtc0
#define ADDU add
#define ADDIU addi
#define R_SZ 4
#define F_SZ 4
#define SZ_INT 4
#define SZ_INT_POW2 2
#else
#error "mips assembly: what size registers do I deal with?"
#endif
#define ISR_VEC_SIZE 4
#define EXCP_STACK_SIZE (NREGS*R_SZ)
#ifdef __GNUC__
#define ASM_EXTERN(x,size) .extern x,size
#else
@@ -158,6 +160,7 @@
FRAME(_CPU_Context_save_fp,sp,0,ra)
.set noat
ld a1,(a0)
NOP
swc1 $f0,FP0_OFFSET*F_SZ(a1)
swc1 $f1,FP1_OFFSET*F_SZ(a1)
swc1 $f2,FP2_OFFSET*F_SZ(a1)
@@ -218,6 +221,7 @@ ENDFRAME(_CPU_Context_save_fp)
FRAME(_CPU_Context_restore_fp,sp,0,ra)
.set noat
ld a1,(a0)
NOP
lwc1 $f0,FP0_OFFSET*4(a1)
lwc1 $f1,FP1_OFFSET*4(a1)
lwc1 $f2,FP2_OFFSET*4(a1)
@@ -269,14 +273,14 @@ ENDFRAME(_CPU_Context_restore_fp)
FRAME(_CPU_Context_switch,sp,0,ra)
mfc0 t0,C0_SR
MFC0 t0,C0_SR
li t1,~(SR_INTERRUPT_ENABLE_BITS)
STREG t0,C0_SR_OFFSET*4(a0) /* save status register */
and t0,t1
mtc0 t0,C0_SR /* first disable ie bit (recommended) */
MTC0 t0,C0_SR /* first disable ie bit (recommended) */
#if __mips == 3
ori t0,SR_EXL|SR_IE /* enable exception level to disable interrupts */
mtc0 t0,C0_SR
ori t0,SR_EXL|SR_IE /* enable exception level to disable interrupts */
MTC0 t0,C0_SR
#endif
STREG ra,RA_OFFSET*R_SZ(a0) /* save current context */
@@ -292,9 +296,13 @@ FRAME(_CPU_Context_switch,sp,0,ra)
STREG s7,S7_OFFSET*R_SZ(a0)
MFC0 t0,C0_EPC
NOP
STREG t0,C0_EPC_OFFSET*R_SZ(a0)
_CPU_Context_switch_restore:
LDREG ra,RA_OFFSET*R_SZ(a1)
LDREG sp,SP_OFFSET*R_SZ(a1)
LDREG fp,FP_OFFSET*R_SZ(a1)
LDREG s0,S0_OFFSET*R_SZ(a1) /* restore context */
LDREG s1,S1_OFFSET*R_SZ(a1)
LDREG s2,S2_OFFSET*R_SZ(a1)
@@ -303,34 +311,34 @@ _CPU_Context_switch_restore:
LDREG s5,S5_OFFSET*R_SZ(a1)
LDREG s6,S6_OFFSET*R_SZ(a1)
LDREG s7,S7_OFFSET*R_SZ(a1)
LDREG fp,FP_OFFSET*R_SZ(a1)
LDREG sp,SP_OFFSET*R_SZ(a1)
LDREG ra,RA_OFFSET*R_SZ(a1)
LDREG t0,C0_EPC_OFFSET*R_SZ(a1)
NOP
MTC0 t0,C0_EPC
LDREG t0, C0_SR_OFFSET*R_SZ(a1)
NOP
#if __mips == 3
andi t0,SR_EXL
bnez t0,_CPU_Context_1 /* set exception level from restore context */
li t0,~SR_EXL
mfc0 t1,C0_SR
nop
MFC0 t1,C0_SR
NOP
and t1,t0
mtc0 t1,C0_SR
MTC0 t1,C0_SR
#elif __mips == 1
andi t0,(SR_INTERRUPT_ENABLE_BITS) /* we know 0 disabled */
beq t0,$0,_CPU_Context_1 /* set level from restore context */
mfc0 t0,C0_SR
nop
MFC0 t0,C0_SR
NOP
or t0,(SR_INTERRUPT_ENABLE_BITS) /* new_sr = old sr with enabled */
mtc0 t0,C0_SR /* set with enabled */
MTC0 t0,C0_SR /* set with enabled */
#endif
_CPU_Context_1:
j ra
nop
NOP
ENDFRAME(_CPU_Context_switch)
/*
@@ -349,7 +357,7 @@ ENDFRAME(_CPU_Context_switch)
FRAME(_CPU_Context_restore,sp,0,ra)
ADD a1,a0,zero
j _CPU_Context_switch_restore
nop
NOP
ENDFRAME(_CPU_Context_restore)
ASM_EXTERN(_ISR_Nest_level, SZ_INT)
@@ -416,38 +424,34 @@ FRAME(_ISR_Handler,sp,0,ra)
STREG t9, R_T9*R_SZ(sp)
mfhi k0
STREG gp, R_GP*R_SZ(sp)
STREG fp, R_FP*R_SZ(sp)
STREG k0, R_MDHI*R_SZ(sp)
STREG fp, R_FP*R_SZ(sp)
.set noat
STREG AT, R_AT*R_SZ(sp)
.set at
/* Q: Why hardcode -40 for stack add??? */
/* This needs to be figured out.........*/
ADDIU sp,sp,-40
STREG ra,32(sp) /* store ra on the stack */
MFC0 t0, C0_EPC /* XXX */
STREG t0,16(sp) /* XXX store EPC on the stack */
mfc0 t0,C0_SR
STREG t0,24(sp) /* XXX store SR on the stack */
MFC0 t0,C0_EPC /* XXX */
MFC0 t1,C0_SR
STREG t0,R_EPC*R_SZ(sp) /* XXX store EPC on the stack */
STREG t1,R_SR*R_SZ(sp) /* XXX store SR on the stack */
/* determine if an interrupt generated this exception */
mfc0 k0,C0_CAUSE
MFC0 k0,C0_CAUSE
NOP
and k1,k0,CAUSE_EXCMASK
beq k1, 0, _ISR_Handler_1
nop
_ISR_Handler_Exception:
nop
b _ISR_Handler_Exception /* Jump to the exception code */
jal mips_vector_exceptions
nop
_ISR_Handler_1:
mfc0 k1,C0_SR
and k0,k1
MFC0 k1,C0_SR
and k0,CAUSE_IPMASK
and k0,k1
beq k0,zero,_ISR_Handler_exit
/* external interrupt not enabled, ignore */
/* but if it's not an exception or an interrupt, */
@@ -468,12 +472,14 @@ _ISR_Handler_1:
* _ISR_Nest_level++;
*/
LDREG t0,_ISR_Nest_level
NOP
ADD t0,t0,1
STREG t0,_ISR_Nest_level
/*
* _Thread_Dispatch_disable_level++;
*/
LDREG t1,_Thread_Dispatch_disable_level
NOP
ADD t1,t1,1
STREG t1,_Thread_Dispatch_disable_level
@@ -489,12 +495,14 @@ _ISR_Handler_1:
* --_ISR_Nest_level;
*/
LDREG t2,_ISR_Nest_level
NOP
ADD t2,t2,-1
STREG t2,_ISR_Nest_level
/*
* --_Thread_Dispatch_disable_level;
*/
LDREG t1,_Thread_Dispatch_disable_level
NOP
ADD t1,t1,-1
STREG t1,_Thread_Dispatch_disable_level
/*
@@ -514,39 +522,53 @@ _ISR_Handler_1:
*/
LDREG t0,_Context_Switch_necessary
LDREG t1,_ISR_Signals_to_thread_executing
NOP
or t0,t0,t1
beq t0,zero,_ISR_Handler_exit
nop
/*
* call _Thread_Dispatch() or prepare to return to _ISR_Dispatch
*/
LDREG t0,R_SR*R_SZ(sp) /* XXX restore SR on the stack */
NOP
MTC0 t0,C0_SR
la t0,_ISR_Dispatch
MTC0 t0, C0_EPC /* XXX */
NOP
j t0
rfe /* go to _ISR_Dispatch in task mode */
_ISR_Dispatch:
jal _Thread_Dispatch
nop
li t0,0x10011001
sw t0,0x8001ff00
nop
/*
* prepare to get out of interrupt
* return from interrupt (maybe to _ISR_Dispatch)
*
* LABEL "exit interrupt (simple case):
* LABEL "exit interrupt (simple case):"
* prepare to get out of interrupt
* return from interrupt
*/
_ISR_Handler_exit:
LDREG ra,32(sp)
LDREG t0,16(sp) /* XXX restore EPC on the stack */
LDREG t0, R_EPC*R_SZ(sp) /* XXX restore EPC on the stack */
LDREG t1, R_SR*R_SZ(sp) /* XXX restore SR on the stack */
MTC0 t0, C0_EPC /* XXX */
LDREG t0,24(sp) /* XXX restore SR on the stack */
mtc0 t0,C0_SR
ADDIU sp,sp,40 /* Q: Again with the 40...Is this needed? */
MTC0 t1, C0_SR
/* restore interrupt context from stack */
LDREG k0, R_MDLO*R_SZ(sp)
LDREG k0, R_MDLO*R_SZ(sp)
LDREG a2, R_A2*R_SZ(sp)
mtlo k0
LDREG k0, R_MDHI*R_SZ(sp)
LDREG a2, R_A2*R_SZ(sp)
mthi k0
LDREG a3, R_A3*R_SZ(sp)
mthi k0
LDREG t0, R_T0*R_SZ(sp)
LDREG t1, R_T1*R_SZ(sp)
LDREG t2, R_T2*R_SZ(sp)
@@ -568,13 +590,12 @@ _ISR_Handler_exit:
LDREG AT, R_AT*R_SZ(sp)
.set at
ADDIU sp,sp,EXCP_STACK_SIZE
ADDIU sp,sp,EXCP_STACK_SIZE
MFC0 k0, C0_EPC
nop
rfe /* Might not need to do RFE here... */
NOP
j k0
rfe /* Might not need to do RFE here... */
nop
.set reorder
@@ -590,3 +611,4 @@ FRAME(mips_break,sp,0,ra)
nop
ENDFRAME(mips_break)