diff options
Diffstat (limited to 'arch/blackfin/kernel/entry.S')
| -rw-r--r-- | arch/blackfin/kernel/entry.S | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/blackfin/kernel/entry.S b/arch/blackfin/kernel/entry.S new file mode 100644 index 000000000..4071265fc --- /dev/null +++ b/arch/blackfin/kernel/entry.S @@ -0,0 +1,59 @@ +/* + * 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) |