arch/sparc/lib/bzero.S

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

File Facts

System: Linux kernel
Corpus path: arch/sparc/lib/bzero.S
Extension: .S
Size: 3476 bytes
Lines: 151
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.

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.

Dependency Surface

linux/export.h
linux/linkage.h

Detected Declarations

export __bzero
export memset
export __clear_user

Annotated Snippet

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

	.text

ENTRY(memset) /* %o0=buf, %o1=pat, %o2=len */
	and		%o1, 0xff, %o3
	mov		%o2, %o1
	sllx		%o3, 8, %g1
	or		%g1, %o3, %o2
	sllx		%o2, 16, %g1
	or		%g1, %o2, %o2
	sllx		%o2, 32, %g1
	ba,pt		%xcc, 1f
	 or		%g1, %o2, %o2

ENTRY(__bzero) /* %o0=buf, %o1=len */
	clr		%o2
1:	mov		%o0, %o3
	brz,pn		%o1, __bzero_done
	 cmp		%o1, 16
	bl,pn		%icc, __bzero_tiny
	 prefetch	[%o0 + 0x000], #n_writes
	andcc		%o0, 0x3, %g0
	be,pt		%icc, 2f
1:	 stb		%o2, [%o0 + 0x00]
	add		%o0, 1, %o0
	andcc		%o0, 0x3, %g0
	bne,pn		%icc, 1b
	 sub		%o1, 1, %o1
2:	andcc		%o0, 0x7, %g0
	be,pt		%icc, 3f
	 stw		%o2, [%o0 + 0x00]
	sub		%o1, 4, %o1
	add		%o0, 4, %o0
3:	and		%o1, 0x38, %g1
	cmp		%o1, 0x40
	andn		%o1, 0x3f, %o4
	bl,pn		%icc, 5f
	 and		%o1, 0x7, %o1
	prefetch	[%o0 + 0x040], #n_writes
	prefetch	[%o0 + 0x080], #n_writes
	prefetch	[%o0 + 0x0c0], #n_writes
	prefetch	[%o0 + 0x100], #n_writes
	prefetch	[%o0 + 0x140], #n_writes
4:	prefetch	[%o0 + 0x180], #n_writes
	stx		%o2, [%o0 + 0x00]
	stx		%o2, [%o0 + 0x08]
	stx		%o2, [%o0 + 0x10]
	stx		%o2, [%o0 + 0x18]
	stx		%o2, [%o0 + 0x20]
	stx		%o2, [%o0 + 0x28]
	stx		%o2, [%o0 + 0x30]
	stx		%o2, [%o0 + 0x38]
	subcc		%o4, 0x40, %o4
	bne,pt		%icc, 4b
	 add		%o0, 0x40, %o0
	brz,pn		%g1, 6f
	 nop
5:	stx		%o2, [%o0 + 0x00]
	subcc		%g1, 8, %g1
	bne,pt		%icc, 5b
	 add		%o0, 0x8, %o0
6:	brz,pt		%o1, __bzero_done
	 nop
__bzero_tiny:
1:	stb		%o2, [%o0 + 0x00]
	subcc		%o1, 1, %o1
	bne,pt		%icc, 1b
	 add		%o0, 1, %o0

Annotation

Immediate include surface: `linux/export.h`, `linux/linkage.h`.
Detected declarations: `export __bzero`, `export memset`, `export __clear_user`.
Atlas domain: Architecture Layer / arch/sparc.
Implementation status: integration implementation candidate.

Implementation Notes

This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.