OpenCloudOS-Kernel/arch/blackfin/kernel/entry.S

60 lines
1.3 KiB
ArmAsm

/*
* Copyright 2004-2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later
*/
#include <linux/linkage.h>
#include <asm/thread_info.h>
#include <asm/errno.h>
#include <asm/blackfin.h>
#include <asm/asm-offsets.h>
#include <asm/context.S>
#ifdef CONFIG_EXCPT_IRQ_SYSC_L1
.section .l1.text
#else
.text
#endif
ENTRY(_ret_from_fork)
#ifdef CONFIG_IPIPE
/*
* Hw IRQs are off on entry, and we don't want the scheduling tail
* code to starve high priority domains from interrupts while it
* runs. Therefore we first stall the root stage to have the
* virtual interrupt state reflect IMASK.
*/
p0.l = ___ipipe_root_status;
p0.h = ___ipipe_root_status;
r4 = [p0];
bitset(r4, 0);
[p0] = r4;
/*
* Then we may enable hw IRQs, allowing preemption from high
* priority domains. schedule_tail() will do local_irq_enable()
* since Blackfin does not define __ARCH_WANT_UNLOCKED_CTXSW, so
* there is no need to unstall the root domain by ourselves
* afterwards.
*/
p0.l = _bfin_irq_flags;
p0.h = _bfin_irq_flags;
r4 = [p0];
sti r4;
#endif /* CONFIG_IPIPE */
SP += -12;
pseudo_long_call _schedule_tail, p5;
SP += 12;
p1 = [sp++];
r0 = [sp++];
cc = p1 == 0;
if cc jump .Lfork;
sp += -12;
call (p1);
sp += 12;
.Lfork:
RESTORE_CONTEXT
rti;
ENDPROC(_ret_from_fork)