Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux...

[deliverable/linux.git] / arch / mips / kernel / syscall.c

diff --git a/arch/mips/kernel/syscall.c b/arch/mips/kernel/syscall.c
index 8cf3846440401b682b01cf26aaa93ba25699c68c..3fe1fcfa2e7301825427c8f44faf80efc2969ed2 100644 (file)
--- 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 @@ SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
        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(&regs, arg1, arg2);
 
        case MIPS_FIXADE:
                if (arg1 & ~3)