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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 1999-2002 Hewlett-Packard Co
* Stephane Eranian <eranian@hpl.hp.com>
* David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 2002 Ken Chen <kenneth.w.chen@intel.com>
*
* 1/06/01 davidm Tuned for Itanium.
* 2/12/02 kchen Tuned for both Itanium and McKinley
* 3/08/02 davidm Some more tweaking
*/
#include <asm/asmmacro.h>
#include <asm/page.h>
#include <asm/export.h>
#ifdef CONFIG_ITANIUM
# define L3_LINE_SIZE 64 // Itanium L3 line size
# define PREFETCH_LINES 9 // magic number
#else
# define L3_LINE_SIZE 128 // McKinley L3 line size
# define PREFETCH_LINES 12 // magic number
#endif
#define saved_lc r2
#define dst_fetch r3
#define dst1 r8
#define dst2 r9
#define dst3 r10
#define dst4 r11
#define dst_last r31
GLOBAL_ENTRY(clear_page)
.prologue
.regstk 1,0,0,0
mov r16 = PAGE_SIZE/L3_LINE_SIZE-1 // main loop count, -1=repeat/until
.save ar.lc, saved_lc
mov saved_lc = ar.lc
.body
mov ar.lc = (PREFETCH_LINES - 1)
mov dst_fetch = in0
adds dst1 = 16, in0
adds dst2 = 32, in0
;;
.fetch: stf.spill.nta [dst_fetch] = f0, L3_LINE_SIZE
adds dst3 = 48, in0 // executing this multiple times is harmless
br.cloop.sptk.few .fetch
;;
addl dst_last = (PAGE_SIZE - PREFETCH_LINES*L3_LINE_SIZE), dst_fetch
mov ar.lc = r16 // one L3 line per iteration
adds dst4 = 64, in0
;;
#ifdef CONFIG_ITANIUM
// Optimized for Itanium
1: stf.spill.nta [dst1] = f0, 64
stf.spill.nta [dst2] = f0, 64
cmp.lt p8,p0=dst_fetch, dst_last
;;
#else
// Optimized for McKinley
1: stf.spill.nta [dst1] = f0, 64
stf.spill.nta [dst2] = f0, 64
stf.spill.nta [dst3] = f0, 64
stf.spill.nta [dst4] = f0, 128
cmp.lt p8,p0=dst_fetch, dst_last
;;
stf.spill.nta [dst1] = f0, 64
stf.spill.nta [dst2] = f0, 64
#endif
stf.spill.nta [dst3] = f0, 64
(p8) stf.spill.nta [dst_fetch] = f0, L3_LINE_SIZE
br.cloop.sptk.few 1b
;;
mov ar.lc = saved_lc // restore lc
br.ret.sptk.many rp
END(clear_page)
EXPORT_SYMBOL(clear_page)
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