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Commit 50a34dbd authored by Kyle McMartin's avatar Kyle McMartin Committed by Kyle McMartin
Browse files

[PARISC] Add PREEMPT support 



Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent bc8846c5

arch/parisc/Kconfig

+1 −5
Original line number Diff line number Diff line
@@ -177,14 +177,10 @@ config ARCH_DISCONTIGMEM_DEFAULT 
	def_bool y

	depends on ARCH_DISCONTIGMEM_ENABLE



source "kernel/Kconfig.preempt"

source "kernel/Kconfig.hz"

source "mm/Kconfig"



config PREEMPT

	bool

#	bool "Preemptible Kernel"

	default n



config COMPAT

	def_bool y

	depends on 64BIT

arch/parisc/kernel/entry.S

+36 −3
Original line number Diff line number Diff line
@@ -1014,14 +1014,21 @@ intr_restore: 
	nop

	nop



#ifndef CONFIG_PREEMPT

# define intr_do_preempt	intr_restore

#endif /* !CONFIG_PREEMPT */



	.import schedule,code

intr_do_resched:

	/* Only do reschedule if we are returning to user space */

	/* Only call schedule on return to userspace. If we're returning

	 * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise

	 * we jump back to intr_restore.

	 */

	LDREG	PT_IASQ0(%r16), %r20

	CMPIB= 0,%r20,intr_restore /* backward */

	CMPIB=	0, %r20, intr_do_preempt

	nop

	LDREG	PT_IASQ1(%r16), %r20

	CMPIB= 0,%r20,intr_restore /* backward */

	CMPIB=	0, %r20, intr_do_preempt

	nop



#ifdef CONFIG_64BIT
@@ -1037,6 +1044,32 @@ intr_do_resched: 
#endif

	ldo	R%intr_check_sig(%r2), %r2



	/* preempt the current task on returning to kernel

	 * mode from an interrupt, iff need_resched is set,

	 * and preempt_count is 0. otherwise, we continue on

	 * our merry way back to the current running task.

	 */

#ifdef CONFIG_PREEMPT

	.import preempt_schedule_irq,code

intr_do_preempt:

	rsm	PSW_SM_I, %r0		/* disable interrupts */



	/* current_thread_info()->preempt_count */

	mfctl	%cr30, %r1

	LDREG	TI_PRE_COUNT(%r1), %r19

	CMPIB<>	0, %r19, intr_restore	/* if preempt_count > 0 */

	nop				/* prev insn branched backwards */



	/* check if we interrupted a critical path */

	LDREG	PT_PSW(%r16), %r20

	bb,<,n	%r20, 31 - PSW_SM_I, intr_restore

	nop



	BL	preempt_schedule_irq, %r2

	nop



	b	intr_restore		/* ssm PSW_SM_I done by intr_restore */

#endif /* CONFIG_PREEMPT */



	.import do_signal,code

intr_do_signal:

include/asm-parisc/thread_info.h

+2 −1
Original line number Diff line number Diff line
@@ -49,7 +49,8 @@ struct thread_info { 


#endif /* !__ASSEMBLY */



#define PREEMPT_ACTIVE          0x10000000

#define PREEMPT_ACTIVE_BIT	28

#define PREEMPT_ACTIVE		(1 << PREEMPT_ACTIVE_BIT)



/*

 * thread information flags