xtensa: add support for the xtensa processor architecture [2/2]

The Xtensa processor architecture is a configurable, extensible,
and synthesizable 32-bit RISC processor core provided by Tensilica, inc.

This is the second part of the basic architecture port, adding the
'arch/xtensa' directory and a readme file.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/xtensa/include/asm/cacheasm.h b/arch/xtensa/include/asm/cacheasm.h
new file mode 100644
index 0000000..342a817
--- /dev/null
+++ b/arch/xtensa/include/asm/cacheasm.h
@@ -0,0 +1,211 @@
+/*
+ * Copyright (C) 2006 Tensilica Inc.
+ * Copyright (C) 2014 - 2016 Cadence Design Systems Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _XTENSA_CACHEASM_H
+#define _XTENSA_CACHEASM_H
+
+#include <asm/cache.h>
+#include <asm/asmmacro.h>
+#include <linux/stringify.h>
+
+#define PAGE_SIZE 4096
+#define DCACHE_WAY_SIZE (XCHAL_DCACHE_SIZE/XCHAL_DCACHE_WAYS)
+#define ICACHE_WAY_SIZE (XCHAL_ICACHE_SIZE/XCHAL_ICACHE_WAYS)
+#define DCACHE_WAY_SHIFT (XCHAL_DCACHE_SETWIDTH + XCHAL_DCACHE_LINEWIDTH)
+#define ICACHE_WAY_SHIFT (XCHAL_ICACHE_SETWIDTH + XCHAL_ICACHE_LINEWIDTH)
+
+/*
+ * Define cache functions as macros here so that they can be used
+ * by the kernel and boot loader. We should consider moving them to a
+ * library that can be linked by both.
+ *
+ * Locking
+ *
+ *   ___unlock_dcache_all
+ *   ___unlock_icache_all
+ *
+ * Flush and invaldating
+ *
+ *   ___flush_invalidate_dcache_{all|range|page}
+ *   ___flush_dcache_{all|range|page}
+ *   ___invalidate_dcache_{all|range|page}
+ *   ___invalidate_icache_{all|range|page}
+ *
+ */
+
+	.macro	__loop_cache_all ar at insn size line_width
+
+	movi	\ar, 0
+
+	__loopi	\ar, \at, \size, (4 << (\line_width))
+
+	\insn	\ar, 0 << (\line_width)
+	\insn	\ar, 1 << (\line_width)
+	\insn	\ar, 2 << (\line_width)
+	\insn	\ar, 3 << (\line_width)
+
+	__endla	\ar, \at, 4 << (\line_width)
+
+	.endm
+
+
+	.macro	__loop_cache_range ar as at insn line_width
+
+	extui	\at, \ar, 0, \line_width
+	add	\as, \as, \at
+
+	__loops	\ar, \as, \at, \line_width
+	\insn	\ar, 0
+	__endla	\ar, \at, (1 << (\line_width))
+
+	.endm
+
+
+	.macro	__loop_cache_page ar at insn line_width
+
+	__loopi	\ar, \at, PAGE_SIZE, 4 << (\line_width)
+
+	\insn	\ar, 0 << (\line_width)
+	\insn	\ar, 1 << (\line_width)
+	\insn	\ar, 2 << (\line_width)
+	\insn	\ar, 3 << (\line_width)
+
+	__endla	\ar, \at, 4 << (\line_width)
+
+	.endm
+
+
+	.macro	___unlock_dcache_all ar at
+
+#if XCHAL_DCACHE_LINE_LOCKABLE && XCHAL_DCACHE_SIZE
+	__loop_cache_all \ar \at diu XCHAL_DCACHE_SIZE XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___unlock_icache_all ar at
+
+#if XCHAL_ICACHE_LINE_LOCKABLE && XCHAL_ICACHE_SIZE
+	__loop_cache_all \ar \at iiu XCHAL_ICACHE_SIZE XCHAL_ICACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___flush_invalidate_dcache_all ar at
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_all \ar \at diwbi XCHAL_DCACHE_SIZE XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___flush_dcache_all ar at
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_all \ar \at diwb XCHAL_DCACHE_SIZE XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___invalidate_dcache_all ar at
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_all \ar \at dii __stringify(DCACHE_WAY_SIZE) \
+			 XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___invalidate_icache_all ar at
+
+#if XCHAL_ICACHE_SIZE
+	__loop_cache_all \ar \at iii __stringify(ICACHE_WAY_SIZE) \
+			 XCHAL_ICACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+
+	.macro	___flush_invalidate_dcache_range ar as at
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_range \ar \as \at dhwbi XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___flush_dcache_range ar as at
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_range \ar \as \at dhwb XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___invalidate_dcache_range ar as at
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_range \ar \as \at dhi XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___invalidate_icache_range ar as at
+
+#if XCHAL_ICACHE_SIZE
+	__loop_cache_range \ar \as \at ihi XCHAL_ICACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+
+	.macro	___flush_invalidate_dcache_page ar as
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_page \ar \as dhwbi XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro ___flush_dcache_page ar as
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_page \ar \as dhwb XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___invalidate_dcache_page ar as
+
+#if XCHAL_DCACHE_SIZE
+	__loop_cache_page \ar \as dhi XCHAL_DCACHE_LINEWIDTH
+#endif
+
+	.endm
+
+
+	.macro	___invalidate_icache_page ar as
+
+#if XCHAL_ICACHE_SIZE
+	__loop_cache_page \ar \as ihi XCHAL_ICACHE_LINEWIDTH
+#endif
+
+	.endm
+
+#endif	/* _XTENSA_CACHEASM_H */