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>

1 files changed, 81 insertions, 0 deletions

diff --git a/arch/microblaze/kernel/selfmod.c b/arch/microblaze/kernel/selfmod.c
new file mode 100644
index 000000000000..89508bdc9f3c
--- /dev/null
+++ b/arch/microblaze/kernel/selfmod.c
@@ -0,0 +1,81 @@
+/*
+ * 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 */