Module Name: src
Committed By: matt
Date: Tue Mar 31 06:47:47 UTC 2015
Modified Files:
src/sys/arch/riscv/include: proc.h
src/sys/arch/riscv/riscv: genassym.cf locore.S
Log Message:
Optimize the exception handle a little bit more.
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 src/sys/arch/riscv/include/proc.h
cvs rdiff -u -r1.2 -r1.3 src/sys/arch/riscv/riscv/genassym.cf \
src/sys/arch/riscv/riscv/locore.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/riscv/include/proc.h
diff -u src/sys/arch/riscv/include/proc.h:1.2 src/sys/arch/riscv/include/proc.h:1.3
--- src/sys/arch/riscv/include/proc.h:1.2 Tue Mar 31 01:12:29 2015
+++ src/sys/arch/riscv/include/proc.h Tue Mar 31 06:47:47 2015
@@ -1,4 +1,4 @@
-/* $NetBSD: proc.h,v 1.2 2015/03/31 01:12:29 matt Exp $ */
+/* $NetBSD: proc.h,v 1.3 2015/03/31 06:47:47 matt Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -46,7 +46,7 @@ struct mdlwp {
struct trapframe *md_utf; /* trapframe from userspace */
struct trapframe *md_ktf; /* trapframe from userspace */
struct faultbuf *md_onfault; /* registers to store on fault */
- register_t md_tp; /* for locore.S */
+ register_t md_usp; /* for locore.S */
vaddr_t md_ss_addr; /* single step address for ptrace */
int md_ss_instr; /* single step instruction for ptrace */
volatile int md_astpending; /* AST pending on return to userland */
Index: src/sys/arch/riscv/riscv/genassym.cf
diff -u src/sys/arch/riscv/riscv/genassym.cf:1.2 src/sys/arch/riscv/riscv/genassym.cf:1.3
--- src/sys/arch/riscv/riscv/genassym.cf:1.2 Tue Mar 31 01:12:47 2015
+++ src/sys/arch/riscv/riscv/genassym.cf Tue Mar 31 06:47:47 2015
@@ -1,4 +1,4 @@
-# $NetBSD: genassym.cf,v 1.2 2015/03/31 01:12:47 matt Exp $
+# $NetBSD: genassym.cf,v 1.3 2015/03/31 06:47:47 matt Exp $
#-
# Copyright (c) 2014 The NetBSD Foundation, Inc.
# All rights reserved.
@@ -114,7 +114,7 @@ define L_CPU offsetof(struct lwp, l_cpu
define L_CTXSWTCH offsetof(struct lwp, l_ctxswtch)
define L_MD_ASTPENDING offsetof(struct lwp, l_md.md_astpending)
define L_MD_ONFAULT offsetof(struct lwp, l_md.md_onfault)
-define L_MD_TP offsetof(struct lwp, l_md.md_tp)
+define L_MD_USP offsetof(struct lwp, l_md.md_usp)
define L_MD_UTF offsetof(struct lwp, l_md.md_utf)
define L_MD_KTF offsetof(struct lwp, l_md.md_ktf)
define L_PCB offsetof(struct lwp, l_addr)
Index: src/sys/arch/riscv/riscv/locore.S
diff -u src/sys/arch/riscv/riscv/locore.S:1.2 src/sys/arch/riscv/riscv/locore.S:1.3
--- src/sys/arch/riscv/riscv/locore.S:1.2 Tue Mar 31 01:30:50 2015
+++ src/sys/arch/riscv/riscv/locore.S Tue Mar 31 06:47:47 2015
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.S,v 1.2 2015/03/31 01:30:50 matt Exp $ */
+/* $NetBSD: locore.S,v 1.3 2015/03/31 06:47:47 matt Exp $ */
/*-
* Copyright (c) 2014 The NetBSD Foundation, Inc.
* All rights reserved.
@@ -306,8 +306,8 @@ END(cpu_fast_switchto)
// RISCV only has a simple exception handler handles both synchronous traps
// and interrupts.
ENTRY_NP(cpu_exception_handler)
- csrrw sp, sscratch, sp // swap scratch and stack pointer
- beqz sp, .Lexception_kernel // sp == 0, already on kernel stack
+ csrrw tp, sscratch, tp // swap scratch and thread pointer
+ beqz tp, .Lexception_kernel // tp == 0, already on kernel stack
//
// The execption happened while user code was executing. We need to
// get the pointer to the user trapframe from the LWP md area. Then we
@@ -315,14 +315,14 @@ ENTRY_NP(cpu_exception_handler)
// into tp. We also save the saved SP into the trapframe.
// Upon entry on an exception from user, sscratch will contain curlwp.
//
- REG_S tp, L_MD_TP(sp) // save thread pointer temporarily
- mv tp, sp // put curlwp in thread pointer
+ REG_S sp, L_MD_USP(tp) // save user stack pointer temporarily
PTR_L sp, L_MD_UTF(sp) // trapframe pointer loaded
REG_S t1, TF_T1(sp) // save t1
- csrrw t1, sscratch, zero // save saved stack pointer with 0
- REG_S t1, TF_SP(sp) // save stack pointer
- REG_S t1, L_MD_TP(tp) // get thread pointer from temp store
+ REG_S t1, L_MD_USP(tp) // get user stack pointer
REG_L t1, TF_SP(sp) // save thread pointer in trapframe
+ csrrw t1, sscratch, zero // swap saved thread pointer with 0
+ REG_L t1, TF_TP(sp) // save thread pointer in trapframe
+ li t1, 0 // indicate user exception
j .Lexception_common
//
@@ -333,11 +333,13 @@ ENTRY_NP(cpu_exception_handler)
// trapframe for use by the exception exiting code.
//
.Lexception_kernel:
- csrrw sp, sscratch, zero // get back our stack pointer
+ csrrw tp, sscratch, zero // get back our thread pointer
addi sp, sp, -TF_LEN // allocate stack frame
REG_S t1, TF_T1(sp) // save t1
addi t1, sp, TF_LEN
REG_S t1, TF_SP(sp) // save SP
+ li t1, 1 // indicate kernel exception
+
.Lexception_common:
// Now we save all the temporary registers into the trapframe since
// they will most certainly be changed.
@@ -364,18 +366,19 @@ ENTRY_NP(cpu_exception_handler)
csrr a1, sepc // get execption pc
csrr a2, sstatus // get status
csrr a3, scause // get cause
- csrr a4, sbadaddr // get badaddr
REG_S a1, TF_PC(sp)
INT_S a2, TF_SR(sp)
INT_S a3, TF_CAUSE(sp) // save cause
- REG_S a4, TF_BADADDR(sp)
// Now we've saved the trapfame, the cause is still in a3.
- andi t1, a2, SR_PS // t1 == user or kernel flag
bltz a3, intr_handler // MSB is set if interrupt
+ // badaddr is only relavent for non-interrupts
+ csrr a4, sbadaddr // get badaddr
+ REG_S a4, TF_BADADDR(sp)
+
beqz t1, trap_user // this was a user trap
// This was a kernel exception
call _C_LABEL(cpu_trap) // just call trap to handle it
@@ -438,6 +441,7 @@ _C_LABEL(exception_userexit):
bnez t0, trap_doast // yes, handle it.
csrrci zero, sstatus, SR_EI // disable interrupts
csrw sscratch, tp // show we are coming from userland
+ REG_L tp, TF_TP(sp) // only restore from userland
REG_L s0, TF_S0(sp) // only restore from userland
REG_L s1, TF_S1(sp) // only restore from userland
REG_L s2, TF_S2(sp) // only restore from userland
@@ -450,7 +454,6 @@ _C_LABEL(exception_userexit):
REG_L s9, TF_S9(sp) // only restore from userland
REG_L s10, TF_S10(sp) // only restore from userland
REG_L s11, TF_S11(sp) // only restore from userland
- REG_L tp, TF_TP(sp) // only restore from userland
j exception_kernexit
trap_syscall:
@@ -482,6 +485,7 @@ intr_user:
INT_L t0, L_MD_ASTPENDING(tp) // get astpending
bnez t0, intr_usersave // if one is pending, deal with in
+ csrw sscratch, tp // show we are coming from userland
REG_L tp, TF_TP(sp) // restore thread pointer
j exception_kernexit // do standard exception exit
