[XTENSA] Add support for configurable registers and coprocessors

The Xtensa architecture allows to define custom instructions and
registers. Registers that are bound to a coprocessor are only
accessible if the corresponding enable bit is set, which allows
to implement a 'lazy' context switch mechanism. Other registers
needs to be saved and restore at the time of the context switch
or during interrupt handling.

This patch adds support for these additional states:

- save and restore registers that are used by the compiler upon
  interrupt entry and exit.
- context switch additional registers unbound to any coprocessor
- 'lazy' context switch of registers bound to a coprocessor
- ptrace interface to provide access to additional registers
- update configuration files in include/asm-xtensa/variant-fsf

Signed-off-by: Chris Zankel <chris@zankel.net>

1 files changed, 65 insertions, 10 deletions

diff --git a/include/asm-xtensa/variant-fsf/tie.h b/include/asm-xtensa/variant-fsf/tie.h
index a73c7166491..bf4020116df 100644
--- a/include/asm-xtensa/variant-fsf/tie.h
+++ b/include/asm-xtensa/variant-fsf/tie.h
@@ -1,22 +1,77 @@
 /*
- * Xtensa processor core configuration information.
+ * This header file describes this specific Xtensa processor's TIE extensions
+ * that extend basic Xtensa core functionality.  It is customized to this
+ * Xtensa processor configuration.
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 1999-2006 Tensilica Inc.
+ * Copyright (C) 1999-2007 Tensilica Inc.
  */
 
-#ifndef XTENSA_TIE_H
-#define XTENSA_TIE_H
-
-/*----------------------------------------------------------------------
-			COPROCESSORS and EXTRA STATE
-  ----------------------------------------------------------------------*/
+#ifndef _XTENSA_CORE_TIE_H
+#define _XTENSA_CORE_TIE_H
 
 #define XCHAL_CP_NUM			0	/* number of coprocessors */
-#define XCHAL_CP_MASK			0x00
+#define XCHAL_CP_MAX			0	/* max CP ID + 1 (0 if none) */
+#define XCHAL_CP_MASK			0x00	/* bitmask of all CPs by ID */
+#define XCHAL_CP_PORT_MASK		0x00	/* bitmask of only port CPs */
+
+/*  Basic parameters of each coprocessor:  */
+#define XCHAL_CP7_NAME			"XTIOP"
+#define XCHAL_CP7_IDENT			XTIOP
+#define XCHAL_CP7_SA_SIZE		0	/* size of state save area */
+#define XCHAL_CP7_SA_ALIGN		1	/* min alignment of save area */
+#define XCHAL_CP_ID_XTIOP		7	/* coprocessor ID (0..7) */
+
+/*  Filler info for unassigned coprocessors, to simplify arrays etc:  */
+#define XCHAL_NCP_SA_SIZE		0
+#define XCHAL_NCP_SA_ALIGN		1
+#define XCHAL_CP0_SA_SIZE		0
+#define XCHAL_CP0_SA_ALIGN		1
+#define XCHAL_CP1_SA_SIZE		0
+#define XCHAL_CP1_SA_ALIGN		1
+#define XCHAL_CP2_SA_SIZE		0
+#define XCHAL_CP2_SA_ALIGN		1
+#define XCHAL_CP3_SA_SIZE		0
+#define XCHAL_CP3_SA_ALIGN		1
+#define XCHAL_CP4_SA_SIZE		0
+#define XCHAL_CP4_SA_ALIGN		1
+#define XCHAL_CP5_SA_SIZE		0
+#define XCHAL_CP5_SA_ALIGN		1
+#define XCHAL_CP6_SA_SIZE		0
+#define XCHAL_CP6_SA_ALIGN		1
+
+/*  Save area for non-coprocessor optional and custom (TIE) state:  */
+#define XCHAL_NCP_SA_SIZE		0
+#define XCHAL_NCP_SA_ALIGN		1
+
+/*  Total save area for optional and custom state (NCP + CPn):  */
+#define XCHAL_TOTAL_SA_SIZE		0	/* with 16-byte align padding */
+#define XCHAL_TOTAL_SA_ALIGN		1	/* actual minimum alignment */
+
+#define XCHAL_NCP_SA_NUM	0
+#define XCHAL_NCP_SA_LIST(s)
+#define XCHAL_CP0_SA_NUM	0
+#define XCHAL_CP0_SA_LIST(s)
+#define XCHAL_CP1_SA_NUM	0
+#define XCHAL_CP1_SA_LIST(s)
+#define XCHAL_CP2_SA_NUM	0
+#define XCHAL_CP2_SA_LIST(s)
+#define XCHAL_CP3_SA_NUM	0
+#define XCHAL_CP3_SA_LIST(s)
+#define XCHAL_CP4_SA_NUM	0
+#define XCHAL_CP4_SA_LIST(s)
+#define XCHAL_CP5_SA_NUM	0
+#define XCHAL_CP5_SA_LIST(s)
+#define XCHAL_CP6_SA_NUM	0
+#define XCHAL_CP6_SA_LIST(s)
+#define XCHAL_CP7_SA_NUM	0
+#define XCHAL_CP7_SA_LIST(s)
+
+/* Byte length of instruction from its first nibble (op0 field), per FLIX.  */
+#define XCHAL_OP0_FORMAT_LENGTHS	3,3,3,3,3,3,3,3,2,2,2,2,2,2,3,3
 
-#endif /*XTENSA_CONFIG_TIE_H*/
+#endif /*_XTENSA_CORE_TIE_H*/