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author | Jiri Kosina <jkosina@suse.cz> | 2013-03-27 14:02:27 +0100 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2013-03-27 14:02:27 +0100 |
commit | b3fecf8cab6441527ab057c99d7e6a6d7f6713e5 (patch) | |
tree | d327499840a25fbd1f81e49d5cb6769bdad382f5 /arch/arc/kernel/ctx_sw_asm.S | |
parent | 5b62efd8250d6a751c31d1972e96bfccd19c4679 (diff) | |
parent | 83a44ac8bf4a8e6cbbf0c00ff281a482778f708a (diff) | |
download | lwn-b3fecf8cab6441527ab057c99d7e6a6d7f6713e5.tar.gz lwn-b3fecf8cab6441527ab057c99d7e6a6d7f6713e5.zip |
Merge branch 'for-3.10/hid-driver-transport-cleanups' into for-3.10/mt-hybrid-finger-pen
Diffstat (limited to 'arch/arc/kernel/ctx_sw_asm.S')
-rw-r--r-- | arch/arc/kernel/ctx_sw_asm.S | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/arch/arc/kernel/ctx_sw_asm.S b/arch/arc/kernel/ctx_sw_asm.S new file mode 100644 index 000000000000..d8972345e4c2 --- /dev/null +++ b/arch/arc/kernel/ctx_sw_asm.S @@ -0,0 +1,58 @@ +/* + * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Vineetg: Aug 2009 + * -Moved core context switch macro out of entry.S into this file. + * -This is the more "natural" hand written assembler + */ + +#include <asm/entry.h> /* For the SAVE_* macros */ +#include <asm/asm-offsets.h> +#include <asm/linkage.h> + +;################### Low Level Context Switch ########################## + + .section .sched.text,"ax",@progbits + .align 4 + .global __switch_to + .type __switch_to, @function +__switch_to: + + /* Save regs on kernel mode stack of task */ + st.a blink, [sp, -4] + st.a fp, [sp, -4] + SAVE_CALLEE_SAVED_KERNEL + + /* Save the now KSP in task->thread.ksp */ + st.as sp, [r0, (TASK_THREAD + THREAD_KSP)/4] + + /* + * Return last task in r0 (return reg) + * On ARC, Return reg = First Arg reg = r0. + * Since we already have last task in r0, + * don't need to do anything special to return it + */ + + /* hardware memory barrier */ + sync + + /* + * switch to new task, contained in r1 + * Temp reg r3 is required to get the ptr to store val + */ + SET_CURR_TASK_ON_CPU r1, r3 + + /* reload SP with kernel mode stack pointer in task->thread.ksp */ + ld.as sp, [r1, (TASK_THREAD + THREAD_KSP)/4] + + /* restore the registers */ + RESTORE_CALLEE_SAVED_KERNEL + ld.ab fp, [sp, 4] + ld.ab blink, [sp, 4] + j [blink] + +ARC_EXIT __switch_to |