microblaze_v8: Selfmodified code

Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: John Linn <john.linn@xilinx.com>
Acked-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/selfmod.h

+/*
+ * Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
+ *
+ * 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.
+ */
+
+#ifndef _ASM_MICROBLAZE_SELFMOD_H
+#define _ASM_MICROBLAZE_SELFMOD_H
+
+/*
+ * BARRIER_BASE_ADDR is constant address for selfmod function.
+ * do not change this value - selfmod function is in
+ * arch/microblaze/kernel/selfmod.c: selfmod_function()
+ *
+ * last 16 bits is used for storing register offset
+ */
+
+#define BARRIER_BASE_ADDR	0x1234ff00
+
+void selfmod_function(const int *arr_fce, const unsigned int base);
+
+#endif /* _ASM_MICROBLAZE_SELFMOD_H */

arch/microblaze/kernel/selfmod.c

+/*
+ * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2009 PetaLogix
+ *
+ * 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.
+ */
+
+#include <linux/interrupt.h>
+#include <asm/selfmod.h>
+
+#undef DEBUG
+
+#if __GNUC__ > 3
+#error GCC 4 unsupported SELFMOD. Please disable SELFMOD from menuconfig.
+#endif
+
+#define OPCODE_IMM		0xB0000000
+#define OPCODE_LWI		0xE8000000
+#define OPCODE_LWI_MASK		0xEC000000
+#define OPCODE_RTSD		0xB60F0008 /* return from func: rtsd r15, 8 */
+#define OPCODE_ADDIK		0x30000000
+#define OPCODE_ADDIK_MASK	0xFC000000
+
+#define IMM_BASE	(OPCODE_IMM | (BARRIER_BASE_ADDR >> 16))
+#define LWI_BASE	(OPCODE_LWI | (BARRIER_BASE_ADDR & 0x0000ff00))
+#define LWI_BASE_MASK	(OPCODE_LWI_MASK | (BARRIER_BASE_ADDR & 0x0000ff00))
+#define ADDIK_BASE	(OPCODE_ADDIK | (BARRIER_BASE_ADDR & 0x0000ff00))
+#define ADDIK_BASE_MASK	(OPCODE_ADDIK_MASK | (BARRIER_BASE_ADDR & 0x0000ff00))
+
+#define MODIFY_INSTR {						\
+	pr_debug("%s: curr instr, (%d):0x%x, next(%d):0x%x\n",		\
+		__func__, i, addr[i], i + 1, addr[i + 1]);		\
+	addr[i] = OPCODE_IMM + (base >> 16);				\
+	/* keep instruction opcode and add only last 16bits */		\
+	addr[i + 1] = (addr[i + 1] & 0xffff00ff) + (base & 0xffff);	\
+	__invalidate_icache(addr[i]);					\
+	__invalidate_icache(addr[i + 1]);				\
+	pr_debug("%s: hack instr, (%d):0x%x, next(%d):0x%x\n",		\
+		__func__, i, addr[i], i + 1, addr[i + 1]); }
+
+/* NOTE
+ * self-modified part of code for improvement of interrupt controller
+ * save instruction in interrupt rutine
+ */
+void selfmod_function(const int *arr_fce, const unsigned int base)
+{
+	unsigned int flags, i, j, *addr = NULL;
+
+	local_irq_save(flags);
+	__disable_icache();
+
+	/* zero terminated array */
+	for (j = 0; arr_fce[j] != 0; j++) {
+		/* get start address of function */
+		addr = (unsigned int *) arr_fce[j];
+		pr_debug("%s: func(%d) at 0x%x\n",
+					__func__, j, (unsigned int) addr);
+		for (i = 0; ; i++) {
+			pr_debug("%s: instruction code at %d: 0x%x\n",
+						__func__, i, addr[i]);
+			if (addr[i] == IMM_BASE) {
+				/* detecting of lwi (0xE8) or swi (0xF8) instr
+				 * I can detect both opcode with one mask */
+				if ((addr[i + 1] & LWI_BASE_MASK) == LWI_BASE) {
+					MODIFY_INSTR;
+				} else /* detection addik for ack */
+				if ((addr[i + 1] & ADDIK_BASE_MASK) ==
+								ADDIK_BASE) {
+					MODIFY_INSTR;
+				}
+			} else if (addr[i] == OPCODE_RTSD) {
+				/* return from function means end of function */
+				pr_debug("%s: end of array %d\n", __func__, i);
+				break;
+			}
+		}
+	}
+	local_irq_restore(flags);
+} /* end of self-modified code */