1/*
 2 * Copyright (C) 1999-2002 Hewlett-Packard Co
 3 *	Stephane Eranian <eranian@hpl.hp.com>
 4 *	David Mosberger-Tang <davidm@hpl.hp.com>
 5 * Copyright (C) 2002 Ken Chen <kenneth.w.chen@intel.com>
 6 *
 7 * 1/06/01 davidm	Tuned for Itanium.
 8 * 2/12/02 kchen	Tuned for both Itanium and McKinley
 9 * 3/08/02 davidm	Some more tweaking
10 */
11
12#include <asm/asmmacro.h>
13#include <asm/page.h>
14
15#ifdef CONFIG_ITANIUM
16# define L3_LINE_SIZE	64	// Itanium L3 line size
17# define PREFETCH_LINES	9	// magic number
18#else
19# define L3_LINE_SIZE	128	// McKinley L3 line size
20# define PREFETCH_LINES	12	// magic number
21#endif
22
23#define saved_lc	r2
24#define dst_fetch	r3
25#define dst1		r8
26#define dst2		r9
27#define dst3		r10
28#define dst4		r11
29
30#define dst_last	r31
31
32GLOBAL_ENTRY(clear_page)
33	.prologue
34	.regstk 1,0,0,0
35	mov r16 = PAGE_SIZE/L3_LINE_SIZE-1	// main loop count, -1=repeat/until
36	.save ar.lc, saved_lc
37	mov saved_lc = ar.lc
38
39	.body
40	mov ar.lc = (PREFETCH_LINES - 1)
41	mov dst_fetch = in0
42	adds dst1 = 16, in0
43	adds dst2 = 32, in0
44	;;
45.fetch:	stf.spill.nta [dst_fetch] = f0, L3_LINE_SIZE
46	adds dst3 = 48, in0		// executing this multiple times is harmless
47	br.cloop.sptk.few .fetch
48	;;
49	addl dst_last = (PAGE_SIZE - PREFETCH_LINES*L3_LINE_SIZE), dst_fetch
50	mov ar.lc = r16			// one L3 line per iteration
51	adds dst4 = 64, in0
52	;;
53#ifdef CONFIG_ITANIUM
54	// Optimized for Itanium
551:	stf.spill.nta [dst1] = f0, 64
56	stf.spill.nta [dst2] = f0, 64
57	cmp.lt p8,p0=dst_fetch, dst_last
58	;;
59#else
60	// Optimized for McKinley
611:	stf.spill.nta [dst1] = f0, 64
62	stf.spill.nta [dst2] = f0, 64
63	stf.spill.nta [dst3] = f0, 64
64	stf.spill.nta [dst4] = f0, 128
65	cmp.lt p8,p0=dst_fetch, dst_last
66	;;
67	stf.spill.nta [dst1] = f0, 64
68	stf.spill.nta [dst2] = f0, 64
69#endif
70	stf.spill.nta [dst3] = f0, 64
71(p8)	stf.spill.nta [dst_fetch] = f0, L3_LINE_SIZE
72	br.cloop.sptk.few 1b
73	;;
74	mov ar.lc = saved_lc		// restore lc
75	br.ret.sptk.many rp
76END(clear_page)