1 files changed, 79 insertions, 0 deletions
diff --git a/arch/ia64/lib/clear_page.S b/arch/ia64/lib/clear_page.S
new file mode 100644
index 000000000..65b75085c
--- /dev/null
+++ b/arch/ia64/lib/clear_page.S
@@ -0,0 +1,79 @@
+/* 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)