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

   1/*
   2 * Microblaze KGDB support
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file "COPYING" in the main directory of this archive
   6 * for more details.
   7 */
   8
   9#include <linux/kgdb.h>
  10#include <linux/kdebug.h>
  11#include <linux/irq.h>
  12#include <linux/io.h>
  13#include <asm/cacheflush.h>
  14#include <asm/asm-offsets.h>
  15#include <asm/kgdb.h>
  16#include <asm/pvr.h>
  17
  18#define GDB_REG         0
  19#define GDB_PC          32
  20#define GDB_MSR         33
  21#define GDB_EAR         34
  22#define GDB_ESR         35
  23#define GDB_FSR         36
  24#define GDB_BTR         37
  25#define GDB_PVR         38
  26#define GDB_REDR        50
  27#define GDB_RPID        51
  28#define GDB_RZPR        52
  29#define GDB_RTLBX       53
  30#define GDB_RTLBSX      54 /* mfs can't read it */
  31#define GDB_RTLBLO      55
  32#define GDB_RTLBHI      56
  33
  34/* keep pvr separately because it is unchangeble */
  35static struct pvr_s pvr;
  36
  37void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  38{
  39        unsigned int i;
  40        unsigned long *pt_regb = (unsigned long *)regs;
  41        int temp;
  42
  43        /* registers r0 - r31, pc, msr, ear, esr, fsr + do not save pt_mode */
  44        for (i = 0; i < (sizeof(struct pt_regs) / 4) - 1; i++)
  45                gdb_regs[i] = pt_regb[i];
  46
  47        /* Branch target register can't be changed */
  48        __asm__ __volatile__ ("mfs %0, rbtr;" : "=r"(temp) : );
  49        gdb_regs[GDB_BTR] = temp;
  50
  51        /* pvr part  - we have 11 pvr regs */
  52        for (i = 0; i < sizeof(struct pvr_s)/4; i++)
  53                gdb_regs[GDB_PVR + i] = pvr.pvr[i];
  54
  55        /* read special registers - can't be changed */
  56        __asm__ __volatile__ ("mfs %0, redr;" : "=r"(temp) : );
  57        gdb_regs[GDB_REDR] = temp;
  58        __asm__ __volatile__ ("mfs %0, rpid;" : "=r"(temp) : );
  59        gdb_regs[GDB_RPID] = temp;
  60        __asm__ __volatile__ ("mfs %0, rzpr;" : "=r"(temp) : );
  61        gdb_regs[GDB_RZPR] = temp;
  62        __asm__ __volatile__ ("mfs %0, rtlbx;" : "=r"(temp) : );
  63        gdb_regs[GDB_RTLBX] = temp;
  64        __asm__ __volatile__ ("mfs %0, rtlblo;" : "=r"(temp) : );
  65        gdb_regs[GDB_RTLBLO] = temp;
  66        __asm__ __volatile__ ("mfs %0, rtlbhi;" : "=r"(temp) : );
  67        gdb_regs[GDB_RTLBHI] = temp;
  68}
  69
  70void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  71{
  72        unsigned int i;
  73        unsigned long *pt_regb = (unsigned long *)regs;
  74
  75        /* pt_regs and gdb_regs have the same 37 values.
  76         * The rest of gdb_regs are unused and can't be changed.
  77         * r0 register value can't be changed too. */
  78        for (i = 1; i < (sizeof(struct pt_regs) / 4) - 1; i++)
  79                pt_regb[i] = gdb_regs[i];
  80}
  81
  82asmlinkage void microblaze_kgdb_break(struct pt_regs *regs)
  83{
  84        if (kgdb_handle_exception(1, SIGTRAP, 0, regs) != 0)
  85                return;
  86
  87        /* Jump over the first arch_kgdb_breakpoint which is barrier to
  88         * get kgdb work. The same solution is used for powerpc */
  89        if (*(u32 *) (regs->pc) == *(u32 *) (&arch_kgdb_ops.gdb_bpt_instr))
  90                regs->pc += BREAK_INSTR_SIZE;
  91}
  92
  93/* untested */
  94void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  95{
  96        unsigned int i;
  97        unsigned long *pt_regb = (unsigned long *)(p->thread.regs);
  98
  99        /* registers r0 - r31, pc, msr, ear, esr, fsr + do not save pt_mode */
 100        for (i = 0; i < (sizeof(struct pt_regs) / 4) - 1; i++)
 101                gdb_regs[i] = pt_regb[i];
 102
 103        /* pvr part  - we have 11 pvr regs */
 104        for (i = 0; i < sizeof(struct pvr_s)/4; i++)
 105                gdb_regs[GDB_PVR + i] = pvr.pvr[i];
 106}
 107
 108void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 109{
 110        regs->pc = ip;
 111}
 112
 113int kgdb_arch_handle_exception(int vector, int signo, int err_code,
 114                               char *remcom_in_buffer, char *remcom_out_buffer,
 115                               struct pt_regs *regs)
 116{
 117        char *ptr;
 118        unsigned long address;
 119
 120        switch (remcom_in_buffer[0]) {
 121        case 'c':
 122                /* handle the optional parameter */
 123                ptr = &remcom_in_buffer[1];
 124                if (kgdb_hex2long(&ptr, &address))
 125                        regs->pc = address;
 126
 127                return 0;
 128        }
 129        return -1; /* this means that we do not want to exit from the handler */
 130}
 131
 132int kgdb_arch_init(void)
 133{
 134        get_pvr(&pvr); /* Fill PVR structure */
 135        return 0;
 136}
 137
 138void kgdb_arch_exit(void)
 139{
 140        /* Nothing to do */
 141}
 142
 143/*
 144 * Global data
 145 */
 146struct kgdb_arch arch_kgdb_ops = {
 147#ifdef __MICROBLAZEEL__
 148        .gdb_bpt_instr = {0x18, 0x00, 0x0c, 0xba}, /* brki r16, 0x18 */
 149#else
 150        .gdb_bpt_instr = {0xba, 0x0c, 0x00, 0x18}, /* brki r16, 0x18 */
 151#endif
 152};
 153