1/* 2 * Copyright 2004-2009 Analog Devices Inc. 3 * 4 * Licensed under the GPL-2 or later 5 */ 6 7#include <linux/linkage.h> 8#include <asm/thread_info.h> 9#include <asm/errno.h> 10#include <asm/blackfin.h> 11#include <asm/asm-offsets.h> 12 13#include <asm/context.S> 14 15#ifdef CONFIG_EXCPT_IRQ_SYSC_L1 16.section .l1.text 17#else 18.text 19#endif 20 21ENTRY(_ret_from_fork) 22#ifdef CONFIG_IPIPE 23 /* 24 * Hw IRQs are off on entry, and we don't want the scheduling tail 25 * code to starve high priority domains from interrupts while it 26 * runs. Therefore we first stall the root stage to have the 27 * virtual interrupt state reflect IMASK. 28 */ 29 p0.l = ___ipipe_root_status; 30 p0.h = ___ipipe_root_status; 31 r4 = [p0]; 32 bitset(r4, 0); 33 [p0] = r4; 34 /* 35 * Then we may enable hw IRQs, allowing preemption from high 36 * priority domains. schedule_tail() will do local_irq_enable() 37 * since Blackfin does not define __ARCH_WANT_UNLOCKED_CTXSW, so 38 * there is no need to unstall the root domain by ourselves 39 * afterwards. 40 */ 41 p0.l = _bfin_irq_flags; 42 p0.h = _bfin_irq_flags; 43 r4 = [p0]; 44 sti r4; 45#endif /* CONFIG_IPIPE */ 46 SP += -12; 47 pseudo_long_call _schedule_tail, p5; 48 SP += 12; 49 p1 = [sp++]; 50 r0 = [sp++]; 51 cc = p1 == 0; 52 if cc jump .Lfork; 53 sp += -12; 54 call (p1); 55 sp += 12; 56.Lfork: 57 RESTORE_CONTEXT 58 rti; 59ENDPROC(_ret_from_fork) 60