diff options
Diffstat (limited to 'ports/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h')
| -rw-r--r-- | ports/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h | 100 |
1 files changed, 74 insertions, 26 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h b/ports/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h index 9d949955be..fecd3e433a 100644 --- a/ports/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h +++ b/ports/sysdeps/unix/sysv/linux/mips/mips64/n64/sysdep.h @@ -67,25 +67,57 @@ #undef INTERNAL_SYSCALL_ERRNO #define INTERNAL_SYSCALL_ERRNO(val, err) ((void) (err), val) +/* Note that the original Linux syscall restart convention required the + instruction immediately preceding SYSCALL to initialize $v0 with the + syscall number. Then if a restart triggered, $v0 would have been + clobbered by the syscall interrupted, and needed to be reinititalized. + The kernel would decrement the PC by 4 before switching back to the + user mode so that $v0 had been reloaded before SYSCALL was executed + again. This implied the place $v0 was loaded from must have been + preserved across a syscall, e.g. an immediate, static register, stack + slot, etc. + + The convention was relaxed in Linux with a change applied to the kernel + GIT repository as commit 96187fb0bc30cd7919759d371d810e928048249d, that + first appeared in the 2.6.36 release. Since then the kernel has had + code that reloads $v0 upon syscall restart and resumes right at the + SYSCALL instruction, so no special arrangement is needed anymore. + + For backwards compatibility with existing kernel binaries we support + the old convention by choosing the instruction preceding SYSCALL + carefully. This also means we have to force a 32-bit encoding of the + microMIPS MOVE instruction if one is used. */ + +#ifdef __mips_micromips +# define MOVE32 "move32" +#else +# define MOVE32 "move" +#endif + #undef INTERNAL_SYSCALL -#define INTERNAL_SYSCALL(name, err, nr, args...) \ - internal_syscall##nr (, "li\t$2, %2\t\t\t# " #name "\n\t", \ - "i" (SYS_ify (name)), err, args) +#define INTERNAL_SYSCALL(name, err, nr, args...) \ + internal_syscall##nr ("li\t%0, %2\t\t\t# " #name "\n\t", \ + "IK" (SYS_ify (name)), \ + 0, err, args) #undef INTERNAL_SYSCALL_NCS -#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \ - internal_syscall##nr (= number, , "r" (__v0), err, args) +#define INTERNAL_SYSCALL_NCS(number, err, nr, args...) \ + internal_syscall##nr (MOVE32 "\t%0, %2\n\t", \ + "r" (__s0), \ + number, err, args) -#define internal_syscall0(ncs_init, cs_init, input, err, dummy...) \ +#define internal_syscall0(v0_init, input, number, err, dummy...) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a3 asm("$7"); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set reorder" \ : "=r" (__v0), "=r" (__a3) \ @@ -97,17 +129,19 @@ _sys_result; \ }) -#define internal_syscall1(ncs_init, cs_init, input, err, arg1) \ +#define internal_syscall1(v0_init, input, number, err, arg1) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a0 asm("$4") = (long) (arg1); \ register long __a3 asm("$7"); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set reorder" \ : "=r" (__v0), "=r" (__a3) \ @@ -119,18 +153,20 @@ _sys_result; \ }) -#define internal_syscall2(ncs_init, cs_init, input, err, arg1, arg2) \ +#define internal_syscall2(v0_init, input, number, err, arg1, arg2) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a0 asm("$4") = (long) (arg1); \ register long __a1 asm("$5") = (long) (arg2); \ register long __a3 asm("$7"); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set\treorder" \ : "=r" (__v0), "=r" (__a3) \ @@ -142,19 +178,22 @@ _sys_result; \ }) -#define internal_syscall3(ncs_init, cs_init, input, err, arg1, arg2, arg3) \ +#define internal_syscall3(v0_init, input, number, err, \ + arg1, arg2, arg3) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a0 asm("$4") = (long) (arg1); \ register long __a1 asm("$5") = (long) (arg2); \ register long __a2 asm("$6") = (long) (arg3); \ register long __a3 asm("$7"); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set\treorder" \ : "=r" (__v0), "=r" (__a3) \ @@ -166,19 +205,22 @@ _sys_result; \ }) -#define internal_syscall4(ncs_init, cs_init, input, err, arg1, arg2, arg3, arg4) \ +#define internal_syscall4(v0_init, input, number, err, \ + arg1, arg2, arg3, arg4) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a0 asm("$4") = (long) (arg1); \ register long __a1 asm("$5") = (long) (arg2); \ register long __a2 asm("$6") = (long) (arg3); \ register long __a3 asm("$7") = (long) (arg4); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set\treorder" \ : "=r" (__v0), "+r" (__a3) \ @@ -190,12 +232,15 @@ _sys_result; \ }) -#define internal_syscall5(ncs_init, cs_init, input, err, arg1, arg2, arg3, arg4, arg5) \ +#define internal_syscall5(v0_init, input, number, err, \ + arg1, arg2, arg3, arg4, arg5) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a0 asm("$4") = (long) (arg1); \ register long __a1 asm("$5") = (long) (arg2); \ register long __a2 asm("$6") = (long) (arg3); \ @@ -203,7 +248,7 @@ register long __a4 asm("$8") = (long) (arg5); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set\treorder" \ : "=r" (__v0), "+r" (__a3) \ @@ -215,12 +260,15 @@ _sys_result; \ }) -#define internal_syscall6(ncs_init, cs_init, input, err, arg1, arg2, arg3, arg4, arg5, arg6) \ +#define internal_syscall6(v0_init, input, number, err, \ + arg1, arg2, arg3, arg4, arg5, arg6) \ ({ \ long _sys_result; \ \ { \ - register long __v0 asm("$2") ncs_init; \ + register long __s0 asm("$16") __attribute__ ((unused)) \ + = (number); \ + register long __v0 asm("$2"); \ register long __a0 asm("$4") = (long) (arg1); \ register long __a1 asm("$5") = (long) (arg2); \ register long __a2 asm("$6") = (long) (arg3); \ @@ -229,7 +277,7 @@ register long __a5 asm("$9") = (long) (arg6); \ __asm__ volatile ( \ ".set\tnoreorder\n\t" \ - cs_init \ + v0_init \ "syscall\n\t" \ ".set\treorder" \ : "=r" (__v0), "+r" (__a3) \ |