[patch v3 31/36] Hexagon: kgdb support files

Richard Kuo
2011-09-09T01:09:18Z

[-- Attachment #1: kgdb.diff --]
[-- Type: text/plain, Size: 10386 bytes --]

Signed-off-by: Linas Vepstas <linas@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>

---
arch/hexagon/include/asm/kgdb.h | 39 ++++++
arch/hexagon/kernel/kgdb.c | 241 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 280 insertions(+)

Index: linux-hexagon-kernel/arch/hexagon/include/asm/kgdb.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/include/asm/kgdb.h 2011-09-03 20:14:59.814981643 -0500
@@ -0,0 +1,39 @@
+/*
+ * arch/hexagon/include/asm/kgdb.h - Hexagon KGDB Support
+ *
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef __HEXAGON_KGDB_H__
+#define __HEXAGON_KGDB_H__
+
+#define BREAK_INSTR_SIZE 4
+#define CACHE_FLUSH_IS_SAFE 1
+#define BUFMAX ((NUMREGBYTES * 2) + 512)
+
+static inline void arch_kgdb_breakpoint(void)
+{
+ asm("trap0(#0xDB)");
+}
+
+/* Registers:
+ * 32 gpr + sa0/1 + lc0/1 + m0/1 + gp + ugp + pred + pc = 42 total.
+ */
+#define NUMREGBYTES (42*4)
+#define DBG_MAX_REG_NUM 42
+
+#endif /* __HEXAGON_KGDB_H__ */
Index: linux-hexagon-kernel/arch/hexagon/kernel/kgdb.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-hexagon-kernel/arch/hexagon/kernel/kgdb.c 2011-09-03 20:14:59.814981643 -0500
@@ -0,0 +1,241 @@
+/*
+ * arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support
+ *
+ * Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <linux/kdebug.h>
+#include <linux/kgdb.h>
+
+/* All registers are 4 bytes, for now */
+#define GDB_SIZEOF_REG 4
+
+/* The register names are used during printing of the regs;
+ * Keep these at three letters to pretty-print. */
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+ { " r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)},
+ { " r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)},
+ { " r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)},
+ { " r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)},
+ { " r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)},
+ { " r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)},
+ { " r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)},
+ { " r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)},
+ { " r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)},
+ { " r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)},
+ { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)},
+ { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)},
+ { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)},
+ { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)},
+ { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)},
+ { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)},
+ { "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)},
+ { "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)},
+ { "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)},
+ { "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)},
+ { "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)},
+ { "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)},
+ { "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)},
+ { "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)},
+ { "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)},
+ { "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)},
+ { "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)},
+ { "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)},
+ { "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)},
+ { "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)},
+ { "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)},
+ { "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)},
+
+ { "usr", GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)},
+ { "preds", GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)},
+ { " m0", GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)},
+ { " m1", GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)},
+ { "sa0", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)},
+ { "sa1", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)},
+ { "lc0", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)},
+ { "lc1", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)},
+ { " gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)},
+ { "ugp", GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)},
+};
+
+struct kgdb_arch arch_kgdb_ops = {
+ /* trap0(#0xDB) 0x0cdb0054 */
+ .gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c},
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+ if (regno >= DBG_MAX_REG_NUM || regno < 0)
+ return NULL;
+
+ *((unsigned long *) mem) = *((unsigned long *) ((void *)regs +
+ dbg_reg_def[regno].offset));
+
+ 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;
+
+ *((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) =
+ *((unsigned long *) mem);
+
+ return 0;
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+ instruction_pointer(regs) = pc;
+}
+
+#ifdef CONFIG_SMP
+
+/**
+ * kgdb_roundup_cpus - Get other CPUs into a holding pattern
+ * @flags: Current IRQ state
+ *
+ * On SMP systems, we need to get the attention of the other CPUs
+ * and get them be in a known state. This should do what is needed
+ * to get the other CPUs to call kgdb_wait(). Note that on some arches,
+ * the NMI approach is not used for rounding up all the CPUs. For example,
+ * in case of MIPS, smp_call_function() is used to roundup CPUs. In
+ * this case, we have to make sure that interrupts are enabled before
+ * calling smp_call_function(). The argument to this function is
+ * the flags that will be used when restoring the interrupts. There is
+ * local_irq_save() call before kgdb_roundup_cpus().
+ *
+ * On non-SMP systems, this is not called.
+ */
+
+static void hexagon_kgdb_nmi_hook(void *ignored)
+{
+ kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+ smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0);
+}
+#endif
+
+
+/* Not yet working */
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
+ struct task_struct *task)
+{
+ struct pt_regs *thread_regs;
+
+ if (task == NULL)
+ return;
+
+ /* Initialize to zero */
+ memset(gdb_regs, 0, NUMREGBYTES);
+
+ /* Otherwise, we have only some registers from switch_to() */
+ thread_regs = task_pt_regs(task);
+ gdb_regs[0] = thread_regs->r00;
+}
+
+/**
+ * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
+ * @vector: The error vector of the exception that happened.
+ * @signo: The signal number of the exception that happened.
+ * @err_code: The error code of the exception that happened.
+ * @remcom_in_buffer: The buffer of the packet we have read.
+ * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
+ * @regs: The &struct pt_regs of the current process.
+ *
+ * This function MUST handle the 'c' and 's' command packets,
+ * as well packets to set / remove a hardware breakpoint, if used.
+ * If there are additional packets which the hardware needs to handle,
+ * they are handled here. The code should return -1 if it wants to
+ * process more packets, and a %0 or %1 if it wants to exit from the
+ * kgdb callback.
+ *
+ * Not yet working.
+ */
+int kgdb_arch_handle_exception(int vector, int signo, int err_code,
+ char *remcom_in_buffer, char *remcom_out_buffer,
+ struct pt_regs *linux_regs)
+{
+ switch (remcom_in_buffer[0]) {
+ case 's':
+ case 'c':
+ return 0;
+ }
+ /* Stay in the debugger. */
+ return -1;
+}
+
+static int __kgdb_notify(struct die_args *args, unsigned long cmd)
+{
+ struct pt_regs *regs = args->regs;
+#if 0
+ ret = kgdb_handle_exception(args->trapnr & 0xff, args->signr, args->err,
+ regs);
+ if (ret)
+ return NOTIFY_DONE;
+#endif
+ return NOTIFY_STOP;
+}
+
+static int
+kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
+{
+ unsigned long flags;
+ int ret;
+
+ local_irq_save(flags);
+ ret = __kgdb_notify(ptr, cmd);
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+static struct notifier_block kgdb_notifier = {
+ .notifier_call = kgdb_notify,
+
+ /*
+ * Lowest-prio notifier priority, we want to be notified last:
+ */
+ .priority = -INT_MAX,
+};
+
+/**
+ * kgdb_arch_init - Perform any architecture specific initalization.
+ *
+ * This function will handle the initalization of any architecture
+ * specific callbacks.
+ */
+int kgdb_arch_init(void)
+{
+ return register_die_notifier(&kgdb_notifier);
+}
+
+/**
+ * kgdb_arch_exit - Perform any architecture specific uninitalization.
+ *
+ * This function will handle the uninitalization of any architecture
+ * specific callbacks, for dynamic registration and unregistration.
+ */
+void kgdb_arch_exit(void)
+{
+ unregister_die_notifier(&kgdb_notifier);
+}
+