From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001 From: Srikant Patnaik Date: Sun, 11 Jan 2015 12:28:04 +0530 Subject: Moved, renamed, and deleted files The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure. --- arch/blackfin/kernel/fixed_code.S | 155 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 155 insertions(+) create mode 100644 arch/blackfin/kernel/fixed_code.S (limited to 'arch/blackfin/kernel/fixed_code.S') diff --git a/arch/blackfin/kernel/fixed_code.S b/arch/blackfin/kernel/fixed_code.S new file mode 100644 index 00000000..0565917f --- /dev/null +++ b/arch/blackfin/kernel/fixed_code.S @@ -0,0 +1,155 @@ +/* + * This file contains sequences of code that will be copied to a + * fixed location, defined in . The interrupt + * handlers ensure that these sequences appear to be atomic when + * executed from userspace. + * These are aligned to 16 bytes, so that we have some space to replace + * these sequences with something else (e.g. kernel traps if we ever do + * BF561 SMP). + * + * Copyright 2007-2008 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#include +#include +#include +#include + +__INIT + +ENTRY(_fixed_code_start) + +.align 16 +ENTRY(_sigreturn_stub) + P0 = __NR_rt_sigreturn; + EXCPT 0; + /* Speculative execution paranoia. */ +0: JUMP.S 0b; +ENDPROC (_sigreturn_stub) + +.align 16 + /* + * Atomic swap, 8 bit. + * Inputs: P0: memory address to use + * R1: value to store + * Output: R0: old contents of the memory address, zero extended. + */ +ENTRY(_atomic_xchg32) + R0 = [P0]; + [P0] = R1; + rts; +ENDPROC (_atomic_xchg32) + +.align 16 + /* + * Compare and swap, 32 bit. + * Inputs: P0: memory address to use + * R1: compare value + * R2: new value to store + * The new value is stored if the contents of the memory + * address is equal to the compare value. + * Output: R0: old contents of the memory address. + */ +ENTRY(_atomic_cas32) + R0 = [P0]; + CC = R0 == R1; + IF !CC JUMP 1f; + [P0] = R2; +1: + rts; +ENDPROC (_atomic_cas32) + +.align 16 + /* + * Atomic add, 32 bit. + * Inputs: P0: memory address to use + * R0: value to add + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_add32) + R1 = [P0]; + R0 = R1 + R0; + [P0] = R0; + rts; +ENDPROC (_atomic_add32) + +.align 16 + /* + * Atomic sub, 32 bit. + * Inputs: P0: memory address to use + * R0: value to subtract + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_sub32) + R1 = [P0]; + R0 = R1 - R0; + [P0] = R0; + rts; +ENDPROC (_atomic_sub32) + +.align 16 + /* + * Atomic ior, 32 bit. + * Inputs: P0: memory address to use + * R0: value to ior + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_ior32) + R1 = [P0]; + R0 = R1 | R0; + [P0] = R0; + rts; +ENDPROC (_atomic_ior32) + +.align 16 + /* + * Atomic and, 32 bit. + * Inputs: P0: memory address to use + * R0: value to and + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_and32) + R1 = [P0]; + R0 = R1 & R0; + [P0] = R0; + rts; +ENDPROC (_atomic_and32) + +.align 16 + /* + * Atomic xor, 32 bit. + * Inputs: P0: memory address to use + * R0: value to xor + * Outputs: R0: new contents of the memory address. + * R1: previous contents of the memory address. + */ +ENTRY(_atomic_xor32) + R1 = [P0]; + R0 = R1 ^ R0; + [P0] = R0; + rts; +ENDPROC (_atomic_xor32) + +.align 16 + /* + * safe_user_instruction + * Four NOPS are enough to allow the pipeline to speculativily load + * execute anything it wants. After that, things have gone bad, and + * we are stuck - so panic. Since we might be in user space, we can't + * call panic, so just cause a unhandled exception, this should cause + * a dump of the trace buffer so we can tell were we are, and a reboot + */ +ENTRY(_safe_user_instruction) + NOP; NOP; NOP; NOP; + EXCPT 0x4; +ENDPROC(_safe_user_instruction) + +ENTRY(_fixed_code_end) + +__FINIT -- cgit