arch/powerpc/kernel/idle_64e.S

Source file repositories/reference/linux-study-clean/arch/powerpc/kernel/idle_64e.S

File Facts

System
Linux kernel
Corpus path
arch/powerpc/kernel/idle_64e.S
Extension
.S
Size
2124 bytes
Lines
100
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: arch/powerpc
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/threads.h>
#include <asm/reg.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/ppc-opcode.h>
#include <asm/processor.h>
#include <asm/thread_info.h>
#include <asm/epapr_hcalls.h>
#include <asm/hw_irq.h>

/* 64-bit version only for now */
.macro BOOK3E_IDLE name loop
_GLOBAL(\name)
	/* Save LR for later */
	mflr	r0
	std	r0,16(r1)

	/* Hard disable interrupts */
	wrteei	0

	/* Now check if an interrupt came in while we were soft disabled
	 * since we may otherwise lose it (doorbells etc...).
	 */
	lbz	r3,PACAIRQHAPPENED(r13)
	cmpwi	cr0,r3,0
	bne	2f

	/* Now we are going to mark ourselves as soft and hard enabled in
	 * order to be able to take interrupts while asleep. We inform lockdep
	 * of that. We don't actually turn interrupts on just yet tho.
	 */
#ifdef CONFIG_TRACE_IRQFLAGS
	stdu    r1,-128(r1)
	bl	trace_hardirqs_on
	addi    r1,r1,128
#endif
	li	r0,IRQS_ENABLED
	stb	r0,PACAIRQSOFTMASK(r13)
	
	/* Interrupts will make use return to LR, so get something we want
	 * in there
	 */
	bl	1f

	/* And return (interrupts are on) */
	ld	r0,16(r1)
	mtlr	r0
	blr

1:	/* Let's set the _TLF_NAPPING flag so interrupts make us return
	 * to the right spot
	*/
	ld	r11, PACACURRENT(r13)
	ld	r10,TI_LOCAL_FLAGS(r11)
	ori	r10,r10,_TLF_NAPPING
	std	r10,TI_LOCAL_FLAGS(r11)

	/* We can now re-enable hard interrupts and go to sleep */
	wrteei	1
	\loop

2:
	lbz	r10,PACAIRQHAPPENED(r13)
	ori	r10,r10,PACA_IRQ_HARD_DIS
	stb	r10,PACAIRQHAPPENED(r13)
	blr
.endm

.macro BOOK3E_IDLE_LOOP
1:

Annotation

Implementation Notes