[PATCH RESEND] h8300: KGDB support

From: Yoshinori Sato
Date: Thu Dec 10 2015 - 22:16:16 EST


Add KGDB helper for h8300.

Signed-off-by: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
---
arch/h8300/Kconfig | 1 +
arch/h8300/include/asm/kgdb.h | 45 ++++++++++++++
arch/h8300/kernel/Makefile | 2 +
arch/h8300/kernel/entry.S | 18 ++++++
arch/h8300/kernel/kgdb.c | 135 ++++++++++++++++++++++++++++++++++++++++++
5 files changed, 201 insertions(+)
create mode 100644 arch/h8300/include/asm/kgdb.h
create mode 100644 arch/h8300/kernel/kgdb.c

diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index dd3ac75..726d255 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -17,6 +17,7 @@ config H8300
select HAVE_MEMBLOCK
select HAVE_DMA_ATTRS
select CLKSRC_OF
+ select HAVE_ARCH_KGDB

config RWSEM_GENERIC_SPINLOCK
def_bool y
diff --git a/arch/h8300/include/asm/kgdb.h b/arch/h8300/include/asm/kgdb.h
new file mode 100644
index 0000000..726ff8f
--- /dev/null
+++ b/arch/h8300/include/asm/kgdb.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2015 Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#ifndef _ASM_H8300_KGDB_H
+#define _ASM_H8300_KGDB_H
+
+#define CACHE_FLUSH_IS_SAFE 1
+#define BUFMAX 2048
+
+enum regnames {
+ GDB_ER0, GDB_ER1, GDB_ER2, GDB_ER3,
+ GDB_ER4, GDB_ER5, GDB_ER6, GDB_SP,
+ GDB_CCR, GDB_PC,
+ GDB_CYCLLE,
+#if defined(CONFIG_CPU_H8S)
+ GDB_EXR,
+#endif
+ GDB_TICK, GDB_INST,
+#if defined(CONFIG_CPU_H8S)
+ GDB_MACH, GDB_MACL,
+#endif
+ /* do not change the last entry or anything below! */
+ GDB_NUMREGBYTES, /* number of registers */
+};
+
+#define GDB_SIZEOF_REG sizeof(u32)
+#if defined(CONFIG_CPU_H8300H)
+#define DBG_MAX_REG_NUM (13)
+#elif defined(CONFIG_CPU_H8S)
+#define DBG_MAX_REG_NUM (14)
+#endif
+#define NUMREGBYTES (DBG_MAX_REG_NUM * GDB_SIZEOF_REG)
+
+#define BREAK_INSTR_SIZE 2
+static inline void arch_kgdb_breakpoint(void)
+{
+ __asm__ __volatile__("trapa #2");
+}
+
+#endif /* _ASM_H8300_KGDB_H */
diff --git a/arch/h8300/kernel/Makefile b/arch/h8300/kernel/Makefile
index 5bc33f2..253f8e3 100644
--- a/arch/h8300/kernel/Makefile
+++ b/arch/h8300/kernel/Makefile
@@ -17,3 +17,5 @@ obj-$(CONFIG_H8S_SIM) += sim-console.o

obj-$(CONFIG_CPU_H8300H) += ptrace_h.o
obj-$(CONFIG_CPU_H8S) += ptrace_s.o
+
+obj-$(CONFIG_KGDB) += kgdb.o
diff --git a/arch/h8300/kernel/entry.S b/arch/h8300/kernel/entry.S
index 797dfa8..2f045b67 100644
--- a/arch/h8300/kernel/entry.S
+++ b/arch/h8300/kernel/entry.S
@@ -188,7 +188,11 @@ _interrupt_redirect_table:
jsr @_interrupt_entry /* NMI */
jmp @_system_call /* TRAPA #0 (System call) */
.long 0
+#if defined(CONFIG_KGDB)
+ jmp @_kgdb_trap
+#else
.long 0
+#endif
jmp @_trace_break /* TRAPA #3 (breakpoint) */
.rept INTERRUPTS-12
jsr @_interrupt_entry
@@ -405,6 +409,20 @@ _nmi:
mov.l @sp+, er0
jmp @_interrupt_entry

+#if defined(CONFIG_KGDB)
+_kgdb_trap:
+ subs #4,sp
+ SAVE_ALL
+ mov.l sp,er0
+ add.l #LRET,er0
+ mov.l er0,@(LSP,sp)
+ jsr @set_esp0
+ mov.l sp,er0
+ subs #4,er0
+ jsr @h8300_kgdb_trap
+ jmp @ret_from_exception
+#endif
+
.section .bss
_sw_ksp:
.space 4
diff --git a/arch/h8300/kernel/kgdb.c b/arch/h8300/kernel/kgdb.c
new file mode 100644
index 0000000..602e478
--- /dev/null
+++ b/arch/h8300/kernel/kgdb.c
@@ -0,0 +1,135 @@
+/*
+ * H8/300 KGDB support
+ *
+ * Copyright (C) 2015 Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
+ *
+ * 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/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/io.h>
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+ { "er0", GDB_SIZEOF_REG, offsetof(struct pt_regs, er0) },
+ { "er1", GDB_SIZEOF_REG, offsetof(struct pt_regs, er1) },
+ { "er2", GDB_SIZEOF_REG, offsetof(struct pt_regs, er2) },
+ { "er3", GDB_SIZEOF_REG, offsetof(struct pt_regs, er3) },
+ { "er4", GDB_SIZEOF_REG, offsetof(struct pt_regs, er4) },
+ { "er5", GDB_SIZEOF_REG, offsetof(struct pt_regs, er5) },
+ { "er6", GDB_SIZEOF_REG, offsetof(struct pt_regs, er6) },
+ { "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp) },
+ { "ccr", GDB_SIZEOF_REG, offsetof(struct pt_regs, ccr) },
+ { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, pc) },
+ { "cycles", GDB_SIZEOF_REG, -1 },
+#if defined(CONFIG_CPU_H8S)
+ { "exr", GDB_SIZEOF_REG, offsetof(struct pt_regs, exr) },
+#endif
+ { "tick", GDB_SIZEOF_REG, -1 },
+ { "inst", GDB_SIZEOF_REG, -1 },
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+ if (regno >= DBG_MAX_REG_NUM || regno < 0)
+ return NULL;
+
+ switch (regno) {
+ case GDB_CCR:
+#if defined(CONFIG_CPU_H8S)
+ case GDB_EXR:
+#endif
+ *(u32 *)mem = *(u16 *)((void *)regs +
+ dbg_reg_def[regno].offset);
+ break;
+ default:
+ if (dbg_reg_def[regno].offset >= 0)
+ memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+ dbg_reg_def[regno].size);
+ else
+ memset(mem, 0, dbg_reg_def[regno].size);
+ break;
+ }
+ return dbg_reg_def[regno].name;
+}
+
+int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
+{
+ if (regno >= DBG_MAX_REG_NUM || regno < 0)
+ return -EINVAL;
+
+ switch (regno) {
+ case GDB_CCR:
+#if defined(CONFIG_CPU_H8S)
+ case GDB_EXR:
+#endif
+ *(u16 *)((void *)regs +
+ dbg_reg_def[regno].offset) = *(u32 *)mem;
+ break;
+ default:
+ memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+ dbg_reg_def[regno].size);
+ }
+ return 0;
+}
+
+asmlinkage void h8300_kgdb_trap(struct pt_regs *regs)
+{
+ regs->pc &= 0x00ffffff;
+ if (kgdb_handle_exception(10, SIGTRAP, 0, regs))
+ return;
+ if (*(u16 *)(regs->pc) == *(u16 *)&arch_kgdb_ops.gdb_bpt_instr)
+ regs->pc += BREAK_INSTR_SIZE;
+ regs->pc |= regs->ccr << 24;
+}
+
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+ memset((char *)gdb_regs, 0, NUMREGBYTES);
+ gdb_regs[GDB_SP] = p->thread.ksp;
+ gdb_regs[GDB_PC] = KSTK_EIP(p);
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+ regs->pc = pc;
+}
+
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+ char *remcom_in_buffer, char *remcom_out_buffer,
+ struct pt_regs *regs)
+{
+ char *ptr;
+ unsigned long addr;
+
+ switch (remcom_in_buffer[0]) {
+ case 's':
+ case 'c':
+ /* handle the optional parameters */
+ ptr = &remcom_in_buffer[1];
+ if (kgdb_hex2long(&ptr, &addr))
+ regs->pc = addr;
+
+ return 0;
+ }
+
+ return -1; /* this means that we do not want to exit from the handler */
+}
+
+int kgdb_arch_init(void)
+{
+ return 0;
+}
+
+void kgdb_arch_exit(void)
+{
+ /* Nothing to do */
+}
+
+const struct kgdb_arch arch_kgdb_ops = {
+ /* Breakpoint instruction: trapa #2 */
+ .gdb_bpt_instr = { 0x57, 0x20 },
+};
--
2.6.1

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