LXR linux/arch/microblaze/kernel/selfmod.c

   1/*
   2 * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
   3 * Copyright (C) 2009 PetaLogix
   4 *
   5 * This file is subject to the terms and conditions of the GNU General Public
   6 * License. See the file "COPYING" in the main directory of this archive
   7 * for more details.
   8 */
   9
  10#include <linux/interrupt.h>
  11#include <asm/selfmod.h>
  12
  13#undef DEBUG
  14
  15#if __GNUC__ > 3
  16#error GCC 4 unsupported SELFMOD. Please disable SELFMOD from menuconfig.
  17#endif
  18
  19#define OPCODE_IMM              0xB0000000
  20#define OPCODE_LWI              0xE8000000
  21#define OPCODE_LWI_MASK         0xEC000000
  22#define OPCODE_RTSD             0xB60F0008 /* return from func: rtsd r15, 8 */
  23#define OPCODE_ADDIK            0x30000000
  24#define OPCODE_ADDIK_MASK       0xFC000000
  25
  26#define IMM_BASE        (OPCODE_IMM | (BARRIER_BASE_ADDR >> 16))
  27#define LWI_BASE        (OPCODE_LWI | (BARRIER_BASE_ADDR & 0x0000ff00))
  28#define LWI_BASE_MASK   (OPCODE_LWI_MASK | (BARRIER_BASE_ADDR & 0x0000ff00))
  29#define ADDIK_BASE      (OPCODE_ADDIK | (BARRIER_BASE_ADDR & 0x0000ff00))
  30#define ADDIK_BASE_MASK (OPCODE_ADDIK_MASK | (BARRIER_BASE_ADDR & 0x0000ff00))
  31
  32#define MODIFY_INSTR {                                          \
  33        pr_debug("%s: curr instr, (%d):0x%x, next(%d):0x%x\n",          \
  34                __func__, i, addr[i], i + 1, addr[i + 1]);              \
  35        addr[i] = OPCODE_IMM + (base >> 16);                            \
  36        /* keep instruction opcode and add only last 16bits */          \
  37        addr[i + 1] = (addr[i + 1] & 0xffff00ff) + (base & 0xffff);     \
  38        __invalidate_icache(addr[i]);                                   \
  39        __invalidate_icache(addr[i + 1]);                               \
  40        pr_debug("%s: hack instr, (%d):0x%x, next(%d):0x%x\n",          \
  41                __func__, i, addr[i], i + 1, addr[i + 1]); }
  42
  43/* NOTE
  44 * self-modified part of code for improvement of interrupt controller
  45 * save instruction in interrupt rutine
  46 */
  47void selfmod_function(const int *arr_fce, const unsigned int base)
  48{
  49        unsigned int flags, i, j, *addr = NULL;
  50
  51        local_irq_save(flags);
  52        __disable_icache();
  53
  54        /* zero terminated array */
  55        for (j = 0; arr_fce[j] != 0; j++) {
  56                /* get start address of function */
  57                addr = (unsigned int *) arr_fce[j];
  58                pr_debug("%s: func(%d) at 0x%x\n",
  59                                        __func__, j, (unsigned int) addr);
  60                for (i = 0; ; i++) {
  61                        pr_debug("%s: instruction code at %d: 0x%x\n",
  62                                                __func__, i, addr[i]);
  63                        if (addr[i] == IMM_BASE) {
  64                                /* detecting of lwi (0xE8) or swi (0xF8) instr
  65                                 * I can detect both opcode with one mask */
  66                                if ((addr[i + 1] & LWI_BASE_MASK) == LWI_BASE) {
  67                                        MODIFY_INSTR;
  68                                } else /* detection addik for ack */
  69                                if ((addr[i + 1] & ADDIK_BASE_MASK) ==
  70                                                                ADDIK_BASE) {
  71                                        MODIFY_INSTR;
  72                                }
  73                        } else if (addr[i] == OPCODE_RTSD) {
  74                                /* return from function means end of function */
  75                                pr_debug("%s: end of array %d\n", __func__, i);
  76                                break;
  77                        }
  78                }
  79        }
  80        local_irq_restore(flags);
  81} /* end of self-modified code */
  82