/* Assembler macros for CRIS. Copyright (C) 1999, 2001 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include #include #include #include "config.h" #undef SYS_ify #define SYS_ify(syscall_name) (__NR_##syscall_name) #ifdef __ASSEMBLER__ /* For Linux we can use the system call table in the header file /usr/include/asm/unistd.h of the kernel. But these symbols do not follow the SYS_* syntax so we have to redefine the `SYS_ify' macro here. */ #undef SYS_ify #define SYS_ify(syscall_name) __NR_##syscall_name /* ELF-like local names start with `.L'. */ #undef L #define L(name) .L##name /* Linux uses a negative return value to indicate syscall errors, unlike most Unices, which use the condition codes' carry flag. Since version 2.1 the return value of a system call might be negative even if the call succeeded. E.g., the `lseek' system call might return a large offset. Therefore we must not anymore test for < 0, but test for a real error by making sure the value in %eax is a real error number. Linus said he will make sure the no syscall returns a value in -1 .. -4095 as a valid result so we can safely test with -4095. */ /* Syscall wrappers consist of #include PSEUDO (...) ret PSEUDO_END (...) which expand to the following. */ /* Linux takes system call arguments in registers: syscall number R9 arg 1 R10 arg 2 R11 arg 3 R12 arg 4 R13 arg 5 MOF arg 6 SRP The compiler calls us by the C convention: syscall number in the DO_CALL macro arg 1 R10 arg 2 R11 arg 3 R12 arg 4 R13 arg 5 [SP] arg 6 [SP + 4] */ /* Note that we use "bhs", since we want to match (unsigned) -4096 .. 0xffffffff. Using "ble" would match -4096 .. -2**31. */ #define PSEUDO(name, syscall_name, args) \ ENTRY (name) @ \ DOARGS_##args @ \ movu.w SYS_ify (syscall_name),$r9 @ \ break 13 @ \ cmps.w -4096,$r10 @ \ bhs 0f @ \ nop @ \ UNDOARGS_return_##args /* Ouch! We have to remember not to use "ret" in assembly-code. ("Luckily", mnemonics are case-insensitive.) Note that we assume usage is exactly: PSEUDO (...) ret PSEUDO_END (...) so we can put all payload into PSEUDO (except for error handling). */ #define ret #define PSEUDO_END(name) \ 0: @ \ SETUP_PIC @ \ PLTJUMP (syscall_error) @ \ END (name) #define DOARGS_0 #define DOARGS_1 #define DOARGS_2 #define DOARGS_3 #define DOARGS_4 #define DOARGS_5 \ move [$sp],$mof /* To avoid allocating stack-space, we re-use the arg 5 (MOF) entry by storing SRP into it. If called with too-few arguments, we will crash, but that will happen in the general case too. */ #define DOARGS_6 \ DOARGS_5 @ \ move $srp,[$sp] @ \ move [$sp+4],$srp #define UNDOARGS_return_0 \ Ret @ \ nop #define UNDOARGS_return_1 UNDOARGS_return_0 #define UNDOARGS_return_2 UNDOARGS_return_0 #define UNDOARGS_return_3 UNDOARGS_return_0 #define UNDOARGS_return_4 UNDOARGS_return_0 #define UNDOARGS_return_5 UNDOARGS_return_0 /* We assume the following code will be "ret" and "PSEUDO_END". */ #define UNDOARGS_return_return_6 \ jump [$sp] #else /* not __ASSEMBLER__ */ #undef INLINE_SYSCALL #define INLINE_SYSCALL(name, nr, args...) \ ({ \ unsigned long __sys_res; \ register unsigned long __res asm ("r10"); \ LOAD_ARGS_c_##nr (args) \ register unsigned long __callno asm ("r9") \ = SYS_ify (name); \ asm volatile (LOAD_ARGS_asm_##nr (args) \ "break 13" \ : "=r" (__res) \ : ASM_ARGS_##nr (args) \ : ASM_CLOBBER_##nr); \ __sys_res = __res; \ \ if (__sys_res >= (unsigned long) -4096) \ { \ __set_errno (- __sys_res); \ __sys_res = (unsigned long) -1; \ } \ __sys_res; \ }) #define LOAD_ARGS_c_0() #define LOAD_ARGS_asm_0() #define ASM_CLOBBER_0 "memory" #define ASM_ARGS_0() "r" (__callno) #define LOAD_ARGS_c_1(r10) \ LOAD_ARGS_c_0() \ register unsigned long __r10 __asm__ ("r10") = (unsigned long) (r10); #define LOAD_ARGS_asm_1(r10) LOAD_ARGS_asm_0 () #define ASM_CLOBBER_1 ASM_CLOBBER_0 #define ASM_ARGS_1(r10) ASM_ARGS_0 (), "0" (__r10) #define LOAD_ARGS_c_2(r10, r11) \ LOAD_ARGS_c_1(r10) \ register unsigned long __r11 __asm__ ("r11") = (unsigned long) (r11); #define LOAD_ARGS_asm_2(r10, r11) LOAD_ARGS_asm_1 (r10) #define ASM_CLOBBER_2 ASM_CLOBBER_1 #define ASM_ARGS_2(r10, r11) ASM_ARGS_1 (r10), "r" (__r11) #define LOAD_ARGS_c_3(r10, r11, r12) \ LOAD_ARGS_c_2(r10, r11) \ register unsigned long __r12 __asm__ ("r12") = (unsigned long) (r12); #define LOAD_ARGS_asm_3(r10, r11, r12) LOAD_ARGS_asm_2 (r10, r11) #define ASM_CLOBBER_3 ASM_CLOBBER_2 #define ASM_ARGS_3(r10, r11, r12) ASM_ARGS_2 (r10, r11), "r" (__r12) #define LOAD_ARGS_c_4(r10, r11, r12, r13) \ LOAD_ARGS_c_3(r10, r11, r12) \ register unsigned long __r13 __asm__ ("r13") = (unsigned long) (r13); #define LOAD_ARGS_asm_4(r10, r11, r12, r13) LOAD_ARGS_asm_3 (r10, r11, r12) #define ASM_CLOBBER_4 ASM_CLOBBER_3 #define ASM_ARGS_4(r10, r11, r12, r13) ASM_ARGS_3 (r10, r11, r12), "r" (__r13) #define LOAD_ARGS_c_5(r10, r11, r12, r13, mof) \ LOAD_ARGS_c_4(r10, r11, r12, r13) #define LOAD_ARGS_asm_5(r10, r11, r12, r13, mof) \ LOAD_ARGS_asm_4 (r10, r11, r12, r13) "move %5,$mof\n\t" #define ASM_CLOBBER_5 ASM_CLOBBER_4 #define ASM_ARGS_5(r10, r11, r12, r13, mof) \ ASM_ARGS_4 (r10, r11, r12, r13), "g" (mof) #define LOAD_ARGS_c_6(r10, r11, r12, r13, mof, srp) \ LOAD_ARGS_c_5(r10, r11, r12, r13, mof) #define LOAD_ARGS_asm_6(r10, r11, r12, r13, mof, srp) \ LOAD_ARGS_asm_5(r10, r11, r12, r13, mof) \ "move %6,$srp\n\t" #define ASM_CLOBBER_6 ASM_CLOBBER_5, "srp" #define ASM_ARGS_6(r10, r11, r12, r13, mof, srp) \ ASM_ARGS_5 (r10, r11, r12, r13, mof), "g" (srp) #endif /* not __ASSEMBLER__ */