arch/sparc/lib/VISsave.S

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

File Facts

System
Linux kernel
Corpus path
arch/sparc/lib/VISsave.S
Extension
.S
Size
1886 bytes
Lines
85
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/asi.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/visasm.h>
#include <asm/thread_info.h>

	/* On entry: %o5=current FPRS value, %g7 is callers address */
	/* May clobber %o5, %g1, %g2, %g3, %g7, %icc, %xcc */

	/* Nothing special need be done here to handle pre-emption, this
	 * FPU save/restore mechanism is already preemption safe.
	 */
	.text
	.align		32
ENTRY(VISenter)
	ldub		[%g6 + TI_FPDEPTH], %g1
	brnz,a,pn	%g1, 1f
	 cmp		%g1, 1
	stb		%g0, [%g6 + TI_FPSAVED]
	stx		%fsr, [%g6 + TI_XFSR]
9:	jmpl		%g7 + %g0, %g0
	 nop
1:	bne,pn		%icc, 2f

	 srl		%g1, 1, %g1
vis1:	ldub		[%g6 + TI_FPSAVED], %g3
	stx		%fsr, [%g6 + TI_XFSR]
	or		%g3, %o5, %g3
	stb		%g3, [%g6 + TI_FPSAVED]
	rd		%gsr, %g3
	clr		%g1
	ba,pt		%xcc, 3f

	 stx		%g3, [%g6 + TI_GSR]
2:	add		%g6, %g1, %g3
	mov		FPRS_DU | FPRS_DL | FPRS_FEF, %o5
	sll		%g1, 3, %g1
	stb		%o5, [%g3 + TI_FPSAVED]
	rd		%gsr, %g2
	add		%g6, %g1, %g3
	stx		%g2, [%g3 + TI_GSR]

	add		%g6, %g1, %g2
	stx		%fsr, [%g2 + TI_XFSR]
	sll		%g1, 5, %g1
3:	andcc		%o5, FPRS_DL|FPRS_DU, %g0
	be,pn		%icc, 9b
	 add		%g6, TI_FPREGS, %g2
	andcc		%o5, FPRS_DL, %g0

	be,pn		%icc, 4f
	 add		%g6, TI_FPREGS+0x40, %g3
	membar		#Sync
	stda		%f0, [%g2 + %g1] ASI_BLK_P
	stda		%f16, [%g3 + %g1] ASI_BLK_P
	membar		#Sync
	andcc		%o5, FPRS_DU, %g0
	be,pn		%icc, 5f
4:	 add		%g1, 128, %g1
	membar		#Sync
	stda		%f32, [%g2 + %g1] ASI_BLK_P

	stda		%f48, [%g3 + %g1] ASI_BLK_P
5:	membar		#Sync
	ba,pt		%xcc, 80f
	 nop

Annotation

Implementation Notes