arch/powerpc/perf/bhrb.S

Source file repositories/reference/linux-study-clean/arch/powerpc/perf/bhrb.S

File Facts

System
Linux kernel
Corpus path
arch/powerpc/perf/bhrb.S
Extension
.S
Size
991 bytes
Lines
41
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/ppc-opcode.h>

	.text

.balign 8

/* r3 = n  (where n = [0-31])
 * The maximum number of BHRB entries supported with PPC_MFBHRBE instruction
 * is 1024. We have limited number of table entries here as POWER8 implements
 * 32 BHRB entries.
 */

/* .global read_bhrb */
_GLOBAL(read_bhrb)
	cmpldi	r3,31
	bgt	1f
	LOAD_REG_ADDR(r4, bhrb_table)
	sldi	r3,r3,3
	add	r3,r4,r3
	mtctr	r3
	bctr
1:	li	r3,0
	blr

#define MFBHRB_TABLE1(n) PPC_MFBHRBE(R3,n); blr
#define MFBHRB_TABLE2(n) MFBHRB_TABLE1(n); MFBHRB_TABLE1(n+1)
#define MFBHRB_TABLE4(n) MFBHRB_TABLE2(n); MFBHRB_TABLE2(n+2)
#define MFBHRB_TABLE8(n) MFBHRB_TABLE4(n); MFBHRB_TABLE4(n+4)
#define MFBHRB_TABLE16(n) MFBHRB_TABLE8(n); MFBHRB_TABLE8(n+8)
#define MFBHRB_TABLE32(n) MFBHRB_TABLE16(n); MFBHRB_TABLE16(n+16)

bhrb_table:
	MFBHRB_TABLE32(0)

Annotation

Implementation Notes