arch/powerpc/kernel/vdso/getcpu.S

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

File Facts

System
Linux kernel
Corpus path
arch/powerpc/kernel/vdso/getcpu.S
Extension
.S
Size
933 bytes
Lines
51
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 <asm/ppc_asm.h>
#include <asm/vdso.h>

	.text
/*
 * Exact prototype of getcpu
 *
 * int __kernel_getcpu(unsigned *cpu, unsigned *node);
 *
 */
#if defined(CONFIG_PPC64)
V_FUNCTION_BEGIN(__kernel_getcpu)
  .cfi_startproc
	mfspr	r5,SPRN_SPRG_VDSO_READ
	PPC_LCMPI	cr0,r3,0
	PPC_LCMPI	cr1,r4,0
	clrlwi  r6,r5,16
	rlwinm  r7,r5,16,31-15,31-0
	beq	cr0,1f
	stw	r6,0(r3)
1:	crclr	cr0*4+so
	li	r3,0			/* always success */
	beqlr	cr1
	stw	r7,0(r4)
	blr
  .cfi_endproc
V_FUNCTION_END(__kernel_getcpu)
#elif !defined(CONFIG_SMP)
V_FUNCTION_BEGIN(__kernel_getcpu)
  .cfi_startproc
	cmpwi	cr0, r3, 0
	cmpwi	cr1, r4, 0
	li	r5, 0
	beq	cr0, 1f
	stw	r5, 0(r3)
1:	li	r3, 0			/* always success */
	crclr	cr0*4+so
	beqlr	cr1
	stw	r5, 0(r4)
	blr
  .cfi_endproc
V_FUNCTION_END(__kernel_getcpu)
#endif

Annotation

Implementation Notes