arch/sparc/lib/blockops.S

Source file repositories/reference/linux-study-clean/arch/sparc/lib/blockops.S

File Facts

System
Linux kernel
Corpus path
arch/sparc/lib/blockops.S
Extension
.S
Size
2730 bytes
Lines
94
Domain
Architecture Layer
Bucket
arch/sparc
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

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/export.h>
#include <linux/linkage.h>
#include <asm/page.h>

	/* Zero out 64 bytes of memory at (buf + offset).
	 * Assumes %g1 contains zero.
	 */
#define BLAST_BLOCK(buf, offset) \
	std	%g0, [buf + offset + 0x38]; \
	std	%g0, [buf + offset + 0x30]; \
	std	%g0, [buf + offset + 0x28]; \
	std	%g0, [buf + offset + 0x20]; \
	std	%g0, [buf + offset + 0x18]; \
	std	%g0, [buf + offset + 0x10]; \
	std	%g0, [buf + offset + 0x08]; \
	std	%g0, [buf + offset + 0x00];

	/* Copy 32 bytes of memory at (src + offset) to
	 * (dst + offset).
	 */
#define MIRROR_BLOCK(dst, src, offset, t0, t1, t2, t3, t4, t5, t6, t7) \
	ldd	[src + offset + 0x18], t0; \
	ldd	[src + offset + 0x10], t2; \
	ldd	[src + offset + 0x08], t4; \
	ldd	[src + offset + 0x00], t6; \
	std	t0, [dst + offset + 0x18]; \
	std	t2, [dst + offset + 0x10]; \
	std	t4, [dst + offset + 0x08]; \
	std	t6, [dst + offset + 0x00];

	/* Profiling evidence indicates that memset() is
	 * commonly called for blocks of size PAGE_SIZE,
	 * and (2 * PAGE_SIZE) (for kernel stacks)
	 * and with a second arg of zero.  We assume in
	 * all of these cases that the buffer is aligned
	 * on at least an 8 byte boundary.
	 *
	 * Therefore we special case them to make them
	 * as fast as possible.
	 */

	.text
ENTRY(bzero_1page)
/* NOTE: If you change the number of insns of this routine, please check
 * arch/sparc/mm/hypersparc.S */
	/* %o0 = buf */
	or	%g0, %g0, %g1
	or	%o0, %g0, %o1
	or	%g0, (PAGE_SIZE >> 8), %g2
1:
	BLAST_BLOCK(%o0, 0x00)
	BLAST_BLOCK(%o0, 0x40)
	BLAST_BLOCK(%o0, 0x80)
	BLAST_BLOCK(%o0, 0xc0)
	subcc	%g2, 1, %g2
	bne	1b
	 add	%o0, 0x100, %o0

	retl
	 nop
ENDPROC(bzero_1page)
EXPORT_SYMBOL(bzero_1page)

ENTRY(__copy_1page)
/* NOTE: If you change the number of insns of this routine, please check
 * arch/sparc/mm/hypersparc.S */
	/* %o0 = dst, %o1 = src */
	or	%g0, (PAGE_SIZE >> 8), %g1
1:
	MIRROR_BLOCK(%o0, %o1, 0x00, %o2, %o3, %o4, %o5, %g2, %g3, %g4, %g5)

Annotation

Implementation Notes