/*
* 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 */
