Hi,
as all the stuff i had been doing about sysmips were all workarounds
around the compiler not giving a chance of refusing to use registers
or to write only parts of an epilogue i now implemented MIPS_ATOMIC_SET
as an asm routing. The only thing i dont catch right now are page faults
in ll/sc which shouldnt be too hard. This patch at least works but as i dont
have docs on the exact semantics of sysmips i can only guess that this
works.
diff -Nur linux.orig/arch/mips/kernel/Makefile linux/arch/mips/kernel/Makefile
--- linux.orig/arch/mips/kernel/Makefile Mon Apr 9 00:23:08 2001
+++ linux/arch/mips/kernel/Makefile Mon Apr 9 00:23:34 2001
@@ -20,7 +20,7 @@
obj-y += branch.o process.o signal.o entry.o \
traps.o ptrace.o vm86.o ioport.o reset.o \
semaphore.o setup.o syscall.o sysmips.o \
- ipc.o scall_o32.o unaligned.o
+ ipc.o scall_o32.o unaligned.o fast-sysmips.o
obj-$(CONFIG_MODULES) += mips_ksyms.o
ifdef CONFIG_CPU_R3000
@@ -69,5 +69,6 @@
entry.o: entry.S
head.o: head.S
+fast-sysmips.o: fast-sysmips.S
include $(TOPDIR)/Rules.make
diff -Nur linux.orig/arch/mips/kernel/fast-sysmips.S linux/arch/mips/kernel/fast-sysmips.S
--- linux.orig/arch/mips/kernel/fast-sysmips.S Thu Jan 1 01:00:00 1970
+++ linux/arch/mips/kernel/fast-sysmips.S Mon Apr 9 00:28:20 2001
@@ -0,0 +1,85 @@
+/*
+ * MIPS_ATOMIC_SET asm implementation for ll/sc capable cpus
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 Florian Lohoff <flo@rfc822.org>
+ *
+ */
+#include <asm/asm.h>
+#include <asm/mipsregs.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+#include <asm/isadep.h>
+#include <asm/unistd.h>
+#include <asm/sysmips.h>
+#include <asm/offset.h>
+#include <asm/errno.h>
+
+#define PT_TRACESYS 0x00000002
+
+ EXPORT(fast_sysmips)
+
+ .set noreorder
+
+ li t0, MIPS_ATOMIC_SET
+ beq a0, t0, 1f
+ nop
+ j sys_sysmips
+ nop
+
+1:
+
+ # a0 - MIPS_ATOMIC_SET
+ # a1 - mem ptr
+ # a2 - value
+
+ addiu sp, sp, -8 # Reserve space
+ sw a0, (sp) # Save arg0
+
+ addiu a0, a1, 4 # addr+size
+ ori v0, a1, 4 # addr | size
+ lw v1, THREAD_CURDS(gp) # current->thread.current_ds
+ or v0, v0, a0 # addr | size | (addr+size)
+ and v1, v1, v0 # (mask)&(addr | size | (addr+size)
+ bltz v1, 5f
+ nop
+
+2:
+ ll v0, (a1)
+ move t0, a2
+ sc t0, (a1)
+ beqz t0, 2b
+ nop
+
+ sw v0, PT_R2+8(sp) # Result value
+ sw zero, PT_R7+8(sp) # Success indicator
+
+ lw t0, TASK_PTRACE(gp) # syscall tracing enabled?
+ andi t0, PT_TRACESYS
+ bnez t0, 3f
+ nop
+
+4:
+ lw a0, (sp) # Restore arg0
+ addiu sp, sp, 8 # Restore sp
+
+ j o32_ret_from_sys_call
+ nop
+
+3:
+ sw ra, 4(sp)
+ jal syscall_trace
+ nop
+ lw ra, 4(sp)
+ j 4b
+ nop
+
+5:
+ lw a0, (sp) # Restore arg0
+ addiu sp, sp, 8 # Restore sp
+ j ra
+ li v0, -EFAULT
+
diff -Nur linux.orig/arch/mips/kernel/irix5sys.h linux/arch/mips/kernel/irix5sys.h
--- linux.orig/arch/mips/kernel/irix5sys.h Mon Apr 9 00:16:29 2001
+++ linux/arch/mips/kernel/irix5sys.h Sun Apr 8 21:21:16 2001
@@ -69,7 +69,7 @@
SYS(irix_getgid, 0) /* 1047 getgid() V*/
SYS(irix_unimp, 0) /* 1048 (XXX IRIX 4 ssig) V*/
SYS(irix_msgsys, 6) /* 1049 sys_msgsys V*/
-SYS(sys_sysmips, 4) /* 1050 sysmips() HV*/
+SYS(fast_sysmips, 4) /* 1050 sysmips() HV*/
SYS(irix_unimp, 0) /* 1051 XXX sysacct() IV*/
SYS(irix_shmsys, 5) /* 1052 sys_shmsys V*/
SYS(irix_semsys, 0) /* 1053 sys_semsys V*/
diff -Nur linux.orig/arch/mips/kernel/syscalls.h linux/arch/mips/kernel/syscalls.h
--- linux.orig/arch/mips/kernel/syscalls.h Mon Apr 9 00:16:30 2001
+++ linux/arch/mips/kernel/syscalls.h Sun Apr 8 21:21:43 2001
@@ -163,7 +163,7 @@
SYS(sys_writev, 3)
SYS(sys_cacheflush, 3)
SYS(sys_cachectl, 3)
-SYS(sys_sysmips, 4)
+SYS(fast_sysmips, 4)
SYS(sys_ni_syscall, 0) /* 4150 */
SYS(sys_getsid, 1)
SYS(sys_fdatasync, 0)
Flo
--
Florian Lohoff flo@rfc822.org +49-5201-669912
Why is it called "common sense" when nobody seems to have any?
