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/*
 * 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 <linux/config.h>

#include <asm/asmmacro.h>
#include <asm/page.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)