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-rw-r--r--arch/mn10300/kernel/kgdb.c502
1 files changed, 502 insertions, 0 deletions
diff --git a/arch/mn10300/kernel/kgdb.c b/arch/mn10300/kernel/kgdb.c
new file mode 100644
index 00000000..f6c981db
--- /dev/null
+++ b/arch/mn10300/kernel/kgdb.c
@@ -0,0 +1,502 @@
+/* kgdb support for MN10300
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/slab.h>
+#include <linux/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/uaccess.h>
+#include <unit/leds.h>
+#include <unit/serial.h>
+#include <asm/debugger.h>
+#include <asm/serial-regs.h>
+#include "internal.h"
+
+/*
+ * Software single-stepping breakpoint save (used by __switch_to())
+ */
+static struct thread_info *kgdb_sstep_thread;
+u8 *kgdb_sstep_bp_addr[2];
+u8 kgdb_sstep_bp[2];
+
+/*
+ * Copy kernel exception frame registers to the GDB register file
+ */
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ unsigned long ssp = (unsigned long) (regs + 1);
+
+ gdb_regs[GDB_FR_D0] = regs->d0;
+ gdb_regs[GDB_FR_D1] = regs->d1;
+ gdb_regs[GDB_FR_D2] = regs->d2;
+ gdb_regs[GDB_FR_D3] = regs->d3;
+ gdb_regs[GDB_FR_A0] = regs->a0;
+ gdb_regs[GDB_FR_A1] = regs->a1;
+ gdb_regs[GDB_FR_A2] = regs->a2;
+ gdb_regs[GDB_FR_A3] = regs->a3;
+ gdb_regs[GDB_FR_SP] = (regs->epsw & EPSW_nSL) ? regs->sp : ssp;
+ gdb_regs[GDB_FR_PC] = regs->pc;
+ gdb_regs[GDB_FR_MDR] = regs->mdr;
+ gdb_regs[GDB_FR_EPSW] = regs->epsw;
+ gdb_regs[GDB_FR_LIR] = regs->lir;
+ gdb_regs[GDB_FR_LAR] = regs->lar;
+ gdb_regs[GDB_FR_MDRQ] = regs->mdrq;
+ gdb_regs[GDB_FR_E0] = regs->e0;
+ gdb_regs[GDB_FR_E1] = regs->e1;
+ gdb_regs[GDB_FR_E2] = regs->e2;
+ gdb_regs[GDB_FR_E3] = regs->e3;
+ gdb_regs[GDB_FR_E4] = regs->e4;
+ gdb_regs[GDB_FR_E5] = regs->e5;
+ gdb_regs[GDB_FR_E6] = regs->e6;
+ gdb_regs[GDB_FR_E7] = regs->e7;
+ gdb_regs[GDB_FR_SSP] = ssp;
+ gdb_regs[GDB_FR_MSP] = 0;
+ gdb_regs[GDB_FR_USP] = regs->sp;
+ gdb_regs[GDB_FR_MCRH] = regs->mcrh;
+ gdb_regs[GDB_FR_MCRL] = regs->mcrl;
+ gdb_regs[GDB_FR_MCVF] = regs->mcvf;
+ gdb_regs[GDB_FR_DUMMY0] = 0;
+ gdb_regs[GDB_FR_DUMMY1] = 0;
+ gdb_regs[GDB_FR_FS0] = 0;
+}
+
+/*
+ * Extracts kernel SP/PC values understandable by gdb from the values
+ * saved by switch_to().
+ */
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+ gdb_regs[GDB_FR_SSP] = p->thread.sp;
+ gdb_regs[GDB_FR_PC] = p->thread.pc;
+ gdb_regs[GDB_FR_A3] = p->thread.a3;
+ gdb_regs[GDB_FR_USP] = p->thread.usp;
+ gdb_regs[GDB_FR_FPCR] = p->thread.fpu_state.fpcr;
+}
+
+/*
+ * Fill kernel exception frame registers from the GDB register file
+ */
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+ regs->d0 = gdb_regs[GDB_FR_D0];
+ regs->d1 = gdb_regs[GDB_FR_D1];
+ regs->d2 = gdb_regs[GDB_FR_D2];
+ regs->d3 = gdb_regs[GDB_FR_D3];
+ regs->a0 = gdb_regs[GDB_FR_A0];
+ regs->a1 = gdb_regs[GDB_FR_A1];
+ regs->a2 = gdb_regs[GDB_FR_A2];
+ regs->a3 = gdb_regs[GDB_FR_A3];
+ regs->sp = gdb_regs[GDB_FR_SP];
+ regs->pc = gdb_regs[GDB_FR_PC];
+ regs->mdr = gdb_regs[GDB_FR_MDR];
+ regs->epsw = gdb_regs[GDB_FR_EPSW];
+ regs->lir = gdb_regs[GDB_FR_LIR];
+ regs->lar = gdb_regs[GDB_FR_LAR];
+ regs->mdrq = gdb_regs[GDB_FR_MDRQ];
+ regs->e0 = gdb_regs[GDB_FR_E0];
+ regs->e1 = gdb_regs[GDB_FR_E1];
+ regs->e2 = gdb_regs[GDB_FR_E2];
+ regs->e3 = gdb_regs[GDB_FR_E3];
+ regs->e4 = gdb_regs[GDB_FR_E4];
+ regs->e5 = gdb_regs[GDB_FR_E5];
+ regs->e6 = gdb_regs[GDB_FR_E6];
+ regs->e7 = gdb_regs[GDB_FR_E7];
+ regs->sp = gdb_regs[GDB_FR_SSP];
+ /* gdb_regs[GDB_FR_MSP]; */
+ // regs->usp = gdb_regs[GDB_FR_USP];
+ regs->mcrh = gdb_regs[GDB_FR_MCRH];
+ regs->mcrl = gdb_regs[GDB_FR_MCRL];
+ regs->mcvf = gdb_regs[GDB_FR_MCVF];
+ /* gdb_regs[GDB_FR_DUMMY0]; */
+ /* gdb_regs[GDB_FR_DUMMY1]; */
+
+ // regs->fpcr = gdb_regs[GDB_FR_FPCR];
+ // regs->fs0 = gdb_regs[GDB_FR_FS0];
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+ .gdb_bpt_instr = { 0xff },
+ .flags = KGDB_HW_BREAKPOINT,
+};
+
+static const unsigned char mn10300_kgdb_insn_sizes[256] =
+{
+ /* 1 2 3 4 5 6 7 8 9 a b c d e f */
+ 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, /* 0 */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
+ 2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
+ 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
+ 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
+ 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
+ 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
+ 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
+ 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
+ 0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1 /* f */
+};
+
+/*
+ * Attempt to emulate single stepping by means of breakpoint instructions.
+ * Although there is a single-step trace flag in EPSW, its use is not
+ * sufficiently documented and is only intended for use with the JTAG debugger.
+ */
+static int kgdb_arch_do_singlestep(struct pt_regs *regs)
+{
+ unsigned long arg;
+ unsigned size;
+ u8 *pc = (u8 *)regs->pc, *sp = (u8 *)(regs + 1), cur;
+ u8 *x = NULL, *y = NULL;
+ int ret;
+
+ ret = probe_kernel_read(&cur, pc, 1);
+ if (ret < 0)
+ return ret;
+
+ size = mn10300_kgdb_insn_sizes[cur];
+ if (size > 0) {
+ x = pc + size;
+ goto set_x;
+ }
+
+ switch (cur) {
+ /* Bxx (d8,PC) */
+ case 0xc0 ... 0xca:
+ ret = probe_kernel_read(&arg, pc + 1, 1);
+ if (ret < 0)
+ return ret;
+ x = pc + 2;
+ if (arg >= 0 && arg <= 2)
+ goto set_x;
+ y = pc + (s8)arg;
+ goto set_x_and_y;
+
+ /* LXX (d8,PC) */
+ case 0xd0 ... 0xda:
+ x = pc + 1;
+ if (regs->pc == regs->lar)
+ goto set_x;
+ y = (u8 *)regs->lar;
+ goto set_x_and_y;
+
+ /* SETLB - loads the next four bytes into the LIR register
+ * (which mustn't include a breakpoint instruction) */
+ case 0xdb:
+ x = pc + 5;
+ goto set_x;
+
+ /* JMP (d16,PC) or CALL (d16,PC) */
+ case 0xcc:
+ case 0xcd:
+ ret = probe_kernel_read(&arg, pc + 1, 2);
+ if (ret < 0)
+ return ret;
+ x = pc + (s16)arg;
+ goto set_x;
+
+ /* JMP (d32,PC) or CALL (d32,PC) */
+ case 0xdc:
+ case 0xdd:
+ ret = probe_kernel_read(&arg, pc + 1, 4);
+ if (ret < 0)
+ return ret;
+ x = pc + (s32)arg;
+ goto set_x;
+
+ /* RETF */
+ case 0xde:
+ x = (u8 *)regs->mdr;
+ goto set_x;
+
+ /* RET */
+ case 0xdf:
+ ret = probe_kernel_read(&arg, pc + 2, 1);
+ if (ret < 0)
+ return ret;
+ ret = probe_kernel_read(&x, sp + (s8)arg, 4);
+ if (ret < 0)
+ return ret;
+ goto set_x;
+
+ case 0xf0:
+ ret = probe_kernel_read(&cur, pc + 1, 1);
+ if (ret < 0)
+ return ret;
+
+ if (cur >= 0xf0 && cur <= 0xf7) {
+ /* JMP (An) / CALLS (An) */
+ switch (cur & 3) {
+ case 0: x = (u8 *)regs->a0; break;
+ case 1: x = (u8 *)regs->a1; break;
+ case 2: x = (u8 *)regs->a2; break;
+ case 3: x = (u8 *)regs->a3; break;
+ }
+ goto set_x;
+ } else if (cur == 0xfc) {
+ /* RETS */
+ ret = probe_kernel_read(&x, sp, 4);
+ if (ret < 0)
+ return ret;
+ goto set_x;
+ } else if (cur == 0xfd) {
+ /* RTI */
+ ret = probe_kernel_read(&x, sp + 4, 4);
+ if (ret < 0)
+ return ret;
+ goto set_x;
+ } else {
+ x = pc + 2;
+ goto set_x;
+ }
+ break;
+
+ /* potential 3-byte conditional branches */
+ case 0xf8:
+ ret = probe_kernel_read(&cur, pc + 1, 1);
+ if (ret < 0)
+ return ret;
+ x = pc + 3;
+
+ if (cur >= 0xe8 && cur <= 0xeb) {
+ ret = probe_kernel_read(&arg, pc + 2, 1);
+ if (ret < 0)
+ return ret;
+ if (arg >= 0 && arg <= 3)
+ goto set_x;
+ y = pc + (s8)arg;
+ goto set_x_and_y;
+ }
+ goto set_x;
+
+ case 0xfa:
+ ret = probe_kernel_read(&cur, pc + 1, 1);
+ if (ret < 0)
+ return ret;
+
+ if (cur == 0xff) {
+ /* CALLS (d16,PC) */
+ ret = probe_kernel_read(&arg, pc + 2, 2);
+ if (ret < 0)
+ return ret;
+ x = pc + (s16)arg;
+ goto set_x;
+ }
+
+ x = pc + 4;
+ goto set_x;
+
+ case 0xfc:
+ ret = probe_kernel_read(&cur, pc + 1, 1);
+ if (ret < 0)
+ return ret;
+
+ if (cur == 0xff) {
+ /* CALLS (d32,PC) */
+ ret = probe_kernel_read(&arg, pc + 2, 4);
+ if (ret < 0)
+ return ret;
+ x = pc + (s32)arg;
+ goto set_x;
+ }
+
+ x = pc + 6;
+ goto set_x;
+ }
+
+ return 0;
+
+set_x:
+ kgdb_sstep_bp_addr[0] = x;
+ kgdb_sstep_bp_addr[1] = NULL;
+ ret = probe_kernel_read(&kgdb_sstep_bp[0], x, 1);
+ if (ret < 0)
+ return ret;
+ ret = probe_kernel_write(x, &arch_kgdb_ops.gdb_bpt_instr, 1);
+ if (ret < 0)
+ return ret;
+ kgdb_sstep_thread = current_thread_info();
+ debugger_local_cache_flushinv_one(x);
+ return ret;
+
+set_x_and_y:
+ kgdb_sstep_bp_addr[0] = x;
+ kgdb_sstep_bp_addr[1] = y;
+ ret = probe_kernel_read(&kgdb_sstep_bp[0], x, 1);
+ if (ret < 0)
+ return ret;
+ ret = probe_kernel_read(&kgdb_sstep_bp[1], y, 1);
+ if (ret < 0)
+ return ret;
+ ret = probe_kernel_write(x, &arch_kgdb_ops.gdb_bpt_instr, 1);
+ if (ret < 0)
+ return ret;
+ ret = probe_kernel_write(y, &arch_kgdb_ops.gdb_bpt_instr, 1);
+ if (ret < 0) {
+ probe_kernel_write(kgdb_sstep_bp_addr[0],
+ &kgdb_sstep_bp[0], 1);
+ } else {
+ kgdb_sstep_thread = current_thread_info();
+ }
+ debugger_local_cache_flushinv_one(x);
+ debugger_local_cache_flushinv_one(y);
+ return ret;
+}
+
+/*
+ * Remove emplaced single-step breakpoints, returning true if we hit one of
+ * them.
+ */
+static bool kgdb_arch_undo_singlestep(struct pt_regs *regs)
+{
+ bool hit = false;
+ u8 *x = kgdb_sstep_bp_addr[0], *y = kgdb_sstep_bp_addr[1];
+ u8 opcode;
+
+ if (kgdb_sstep_thread == current_thread_info()) {
+ if (x) {
+ if (x == (u8 *)regs->pc)
+ hit = true;
+ if (probe_kernel_read(&opcode, x,
+ 1) < 0 ||
+ opcode != 0xff)
+ BUG();
+ probe_kernel_write(x, &kgdb_sstep_bp[0], 1);
+ debugger_local_cache_flushinv_one(x);
+ }
+ if (y) {
+ if (y == (u8 *)regs->pc)
+ hit = true;
+ if (probe_kernel_read(&opcode, y,
+ 1) < 0 ||
+ opcode != 0xff)
+ BUG();
+ probe_kernel_write(y, &kgdb_sstep_bp[1], 1);
+ debugger_local_cache_flushinv_one(y);
+ }
+ }
+
+ kgdb_sstep_bp_addr[0] = NULL;
+ kgdb_sstep_bp_addr[1] = NULL;
+ kgdb_sstep_thread = NULL;
+ return hit;
+}
+
+/*
+ * Catch a single-step-pending thread being deleted and make sure the global
+ * single-step state is cleared. At this point the breakpoints should have
+ * been removed by __switch_to().
+ */
+void free_thread_info(struct thread_info *ti)
+{
+ if (kgdb_sstep_thread == ti) {
+ kgdb_sstep_thread = NULL;
+
+ /* However, we may now be running in degraded mode, with most
+ * of the CPUs disabled until such a time as KGDB is reentered,
+ * so force immediate reentry */
+ kgdb_breakpoint();
+ }
+ kfree(ti);
+}
+
+/*
+ * Handle unknown packets and [CcsDk] packets
+ * - at this point breakpoints have been installed
+ */
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+ char *remcom_in_buffer, char *remcom_out_buffer,
+ struct pt_regs *regs)
+{
+ long addr;
+ char *ptr;
+
+ switch (remcom_in_buffer[0]) {
+ case 'c':
+ case 's':
+ /* try to read optional parameter, pc unchanged if no parm */
+ ptr = &remcom_in_buffer[1];
+ if (kgdb_hex2long(&ptr, &addr))
+ regs->pc = addr;
+ case 'D':
+ case 'k':
+ atomic_set(&kgdb_cpu_doing_single_step, -1);
+
+ if (remcom_in_buffer[0] == 's') {
+ kgdb_arch_do_singlestep(regs);
+ kgdb_single_step = 1;
+ atomic_set(&kgdb_cpu_doing_single_step,
+ raw_smp_processor_id());
+ }
+ return 0;
+ }
+ return -1; /* this means that we do not want to exit from the handler */
+}
+
+/*
+ * Handle event interception
+ * - returns 0 if the exception should be skipped, -ERROR otherwise.
+ */
+int debugger_intercept(enum exception_code excep, int signo, int si_code,
+ struct pt_regs *regs)
+{
+ int ret;
+
+ if (kgdb_arch_undo_singlestep(regs)) {
+ excep = EXCEP_TRAP;
+ signo = SIGTRAP;
+ si_code = TRAP_TRACE;
+ }
+
+ ret = kgdb_handle_exception(excep, signo, si_code, regs);
+
+ debugger_local_cache_flushinv();
+
+ return ret;
+}
+
+/*
+ * Determine if we've hit a debugger special breakpoint
+ */
+int at_debugger_breakpoint(struct pt_regs *regs)
+{
+ return regs->pc == (unsigned long)&__arch_kgdb_breakpoint;
+}
+
+/*
+ * Initialise kgdb
+ */
+int kgdb_arch_init(void)
+{
+ return 0;
+}
+
+/*
+ * Do something, perhaps, but don't know what.
+ */
+void kgdb_arch_exit(void)
+{
+}
+
+#ifdef CONFIG_SMP
+void debugger_nmi_interrupt(struct pt_regs *regs, enum exception_code code)
+{
+ kgdb_nmicallback(arch_smp_processor_id(), regs);
+ debugger_local_cache_flushinv();
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+ smp_jump_to_debugger();
+}
+#endif
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