arch/sh/lib/copy_page.S

Source file repositories/reference/linux-study-clean/arch/sh/lib/copy_page.S

File Facts

System
Linux kernel
Corpus path
arch/sh/lib/copy_page.S
Extension
.S
Size
6226 bytes
Lines
391
Domain
Architecture Layer
Bucket
arch/sh
Inferred role
Architecture Layer: arch/sh
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/linkage.h>
#include <asm/page.h>

/*
 * copy_page
 * @to: P1 address
 * @from: P1 address
 *
 * void copy_page(void *to, void *from)
 */

/*
 * r0, r1, r2, r3, r4, r5, r6, r7 --- scratch 
 * r8 --- from + PAGE_SIZE
 * r9 --- not used
 * r10 --- to
 * r11 --- from
 */
ENTRY(copy_page)
	mov.l	r8,@-r15
	mov.l	r10,@-r15
	mov.l	r11,@-r15
	mov	r4,r10
	mov	r5,r11
	mov	r5,r8
	mov	#(PAGE_SIZE >> 10), r0
	shll8	r0
	shll2	r0
	add	r0,r8
	!
1:	mov.l	@r11+,r0
	mov.l	@r11+,r1
	mov.l	@r11+,r2
	mov.l	@r11+,r3
	mov.l	@r11+,r4
	mov.l	@r11+,r5
	mov.l	@r11+,r6
	mov.l	@r11+,r7
#if defined(CONFIG_CPU_SH4)
	movca.l	r0,@r10
#else
	mov.l	r0,@r10
#endif
	add	#32,r10
	mov.l	r7,@-r10
	mov.l	r6,@-r10
	mov.l	r5,@-r10
	mov.l	r4,@-r10
	mov.l	r3,@-r10
	mov.l	r2,@-r10
	mov.l	r1,@-r10
	cmp/eq	r11,r8
	bf/s	1b
	 add	#28,r10
	!
	mov.l	@r15+,r11
	mov.l	@r15+,r10
	mov.l	@r15+,r8
	rts
	 nop

/*
 * __kernel_size_t __copy_user(void *to, const void *from, __kernel_size_t n);
 * Return the number of bytes NOT copied
 */
#define EX(...)			\
	9999: __VA_ARGS__ ;		\
	.section __ex_table, "a";	\
	.long 9999b, 6000f	;	\
	.previous

Annotation

Implementation Notes