MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler
This way it doesn't have to use CONFIG_CPU_HAS_LLSC anymore.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/system.h b/arch/mips/include/asm/system.h
index a2e9239..23f68b4 100644
--- a/arch/mips/include/asm/system.h
+++ b/arch/mips/include/asm/system.h
@@ -32,6 +32,9 @@
struct task_struct;
+extern unsigned int ll_bit;
+extern struct task_struct *ll_task;
+
#ifdef CONFIG_MIPS_MT_FPAFF
/*
diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S
index b570821..7c2de4f 100644
--- a/arch/mips/kernel/scall32-o32.S
+++ b/arch/mips/kernel/scall32-o32.S
@@ -187,78 +187,6 @@
j o32_syscall_exit
END(handle_sys)
- LEAF(mips_atomic_set)
- andi v0, a1, 3 # must be word aligned
- bnez v0, bad_alignment
-
- lw v1, TI_ADDR_LIMIT($28) # in legal address range?
- addiu a0, a1, 4
- or a0, a0, a1
- and a0, a0, v1
- bltz a0, bad_address
-
-#ifdef CONFIG_CPU_HAS_LLSC
- /* Ok, this is the ll/sc case. World is sane :-) */
-1: ll v0, (a1)
- move a0, a2
-2: sc a0, (a1)
-#if R10000_LLSC_WAR
- beqzl a0, 1b
-#else
- beqz a0, 1b
-#endif
-
- .section __ex_table,"a"
- PTR 1b, bad_stack
- PTR 2b, bad_stack
- .previous
-#else
- sw a1, 16(sp)
- sw a2, 20(sp)
-
- move a0, sp
- move a2, a1
- li a1, 1
- jal do_page_fault
-
- lw a1, 16(sp)
- lw a2, 20(sp)
-
- /*
- * At this point the page should be readable and writable unless
- * there was no more memory available.
- */
-1: lw v0, (a1)
-2: sw a2, (a1)
-
- .section __ex_table,"a"
- PTR 1b, no_mem
- PTR 2b, no_mem
- .previous
-#endif
-
- sw zero, PT_R7(sp) # success
- sw v0, PT_R2(sp) # result
-
- j o32_syscall_exit # continue like a normal syscall
-
-no_mem: li v0, -ENOMEM
- jr ra
-
-bad_address:
- li v0, -EFAULT
- jr ra
-
-bad_alignment:
- li v0, -EINVAL
- jr ra
- END(mips_atomic_set)
-
- LEAF(sys_sysmips)
- beq a0, MIPS_ATOMIC_SET, mips_atomic_set
- j _sys_sysmips
- END(sys_sysmips)
-
LEAF(sys_syscall)
subu t0, a0, __NR_O32_Linux # check syscall number
sltiu v0, t0, __NR_O32_Linux_syscalls + 1
diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S
index 3d866f2..b97b993 100644
--- a/arch/mips/kernel/scall64-64.S
+++ b/arch/mips/kernel/scall64-64.S
@@ -124,78 +124,6 @@
j n64_syscall_exit
END(handle_sys64)
- LEAF(mips_atomic_set)
- andi v0, a1, 3 # must be word aligned
- bnez v0, bad_alignment
-
- LONG_L v1, TI_ADDR_LIMIT($28) # in legal address range?
- LONG_ADDIU a0, a1, 4
- or a0, a0, a1
- and a0, a0, v1
- bltz a0, bad_address
-
-#ifdef CONFIG_CPU_HAS_LLSC
- /* Ok, this is the ll/sc case. World is sane :-) */
-1: ll v0, (a1)
- move a0, a2
-2: sc a0, (a1)
-#if R10000_LLSC_WAR
- beqzl a0, 1b
-#else
- beqz a0, 1b
-#endif
-
- .section __ex_table,"a"
- PTR 1b, bad_stack
- PTR 2b, bad_stack
- .previous
-#else
- sw a1, 16(sp)
- sw a2, 20(sp)
-
- move a0, sp
- move a2, a1
- li a1, 1
- jal do_page_fault
-
- lw a1, 16(sp)
- lw a2, 20(sp)
-
- /*
- * At this point the page should be readable and writable unless
- * there was no more memory available.
- */
-1: lw v0, (a1)
-2: sw a2, (a1)
-
- .section __ex_table,"a"
- PTR 1b, no_mem
- PTR 2b, no_mem
- .previous
-#endif
-
- sd zero, PT_R7(sp) # success
- sd v0, PT_R2(sp) # result
-
- j n64_syscall_exit # continue like a normal syscall
-
-no_mem: li v0, -ENOMEM
- jr ra
-
-bad_address:
- li v0, -EFAULT
- jr ra
-
-bad_alignment:
- li v0, -EINVAL
- jr ra
- END(mips_atomic_set)
-
- LEAF(sys_sysmips)
- beq a0, MIPS_ATOMIC_SET, mips_atomic_set
- j _sys_sysmips
- END(sys_sysmips)
-
.align 3
sys_call_table:
PTR sys_read /* 5000 */
diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 8cf3846..3fe1fcf 100644
--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -28,7 +28,9 @@
#include <linux/compiler.h>
#include <linux/module.h>
#include <linux/ipc.h>
+#include <linux/uaccess.h>
+#include <asm/asm.h>
#include <asm/branch.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
@@ -290,12 +292,116 @@
return 0;
}
-asmlinkage int _sys_sysmips(long cmd, long arg1, long arg2, long arg3)
+static inline int mips_atomic_set(struct pt_regs *regs,
+ unsigned long addr, unsigned long new)
{
+ unsigned long old, tmp;
+ unsigned int err;
+
+ if (unlikely(addr & 3))
+ return -EINVAL;
+
+ if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
+ return -EINVAL;
+
+ if (cpu_has_llsc && R10000_LLSC_WAR) {
+ __asm__ __volatile__ (
+ " li %[err], 0 \n"
+ "1: ll %[old], (%[addr]) \n"
+ " move %[tmp], %[new] \n"
+ "2: sc %[tmp], (%[addr]) \n"
+ " beqzl %[tmp], 1b \n"
+ "3: \n"
+ " .section .fixup,\"ax\" \n"
+ "4: li %[err], %[efault] \n"
+ " j 3b \n"
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " "STR(PTR)" 1b, 4b \n"
+ " "STR(PTR)" 2b, 4b \n"
+ " .previous \n"
+ : [old] "=&r" (old),
+ [err] "=&r" (err),
+ [tmp] "=&r" (tmp)
+ : [addr] "r" (addr),
+ [new] "r" (new),
+ [efault] "i" (-EFAULT)
+ : "memory");
+ } else if (cpu_has_llsc) {
+ __asm__ __volatile__ (
+ " li %[err], 0 \n"
+ "1: ll %[old], (%[addr]) \n"
+ " move %[tmp], %[new] \n"
+ "2: sc %[tmp], (%[addr]) \n"
+ " bnez %[tmp], 4f \n"
+ "3: \n"
+ " .subsection 2 \n"
+ "4: b 1b \n"
+ " .previous \n"
+ " \n"
+ " .section .fixup,\"ax\" \n"
+ "5: li %[err], %[efault] \n"
+ " j 3b \n"
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " "STR(PTR)" 1b, 5b \n"
+ " "STR(PTR)" 2b, 5b \n"
+ " .previous \n"
+ : [old] "=&r" (old),
+ [err] "=&r" (err),
+ [tmp] "=&r" (tmp)
+ : [addr] "r" (addr),
+ [new] "r" (new),
+ [efault] "i" (-EFAULT)
+ : "memory");
+ } else {
+ do {
+ preempt_disable();
+ ll_bit = 1;
+ ll_task = current;
+ preempt_enable();
+
+ err = __get_user(old, (unsigned int *) addr);
+ err |= __put_user(new, (unsigned int *) addr);
+ if (err)
+ break;
+ rmb();
+ } while (!ll_bit);
+ }
+
+ if (unlikely(err))
+ return err;
+
+ regs->regs[2] = old;
+ regs->regs[7] = 0; /* No error */
+
+ /*
+ * Don't let your children do this ...
+ */
+ __asm__ __volatile__(
+ " move $29, %0 \n"
+ " j syscall_exit \n"
+ : /* no outputs */
+ : "r" (regs));
+
+ /* unreached. Honestly. */
+ while (1);
+}
+
+save_static_function(sys_sysmips);
+static int __used noinline
+_sys_sysmips(nabi_no_regargs struct pt_regs regs)
+{
+ long cmd, arg1, arg2, arg3;
+
+ cmd = regs.regs[4];
+ arg1 = regs.regs[5];
+ arg2 = regs.regs[6];
+ arg3 = regs.regs[7];
+
switch (cmd) {
case MIPS_ATOMIC_SET:
- printk(KERN_CRIT "How did I get here?\n");
- return -EINVAL;
+ return mips_atomic_set(®s, arg1, arg2);
case MIPS_FIXADE:
if (arg1 & ~3)
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 08f1edf..0a18b4c 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -466,9 +466,8 @@
* The ll_bit is cleared by r*_switch.S
*/
-unsigned long ll_bit;
-
-static struct task_struct *ll_task = NULL;
+unsigned int ll_bit;
+struct task_struct *ll_task;
static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
{
