1 files changed, 336 insertions, 0 deletions

diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c
new file mode 100644
index 000000000000..75c9cf1aafee
--- /dev/null
+++ b/arch/arm64/kernel/kgdb.c
@@ -0,0 +1,336 @@
+/*
+ * AArch64 KGDB support
+ *
+ * Based on arch/arm/kernel/kgdb.c
+ *
+ * Copyright (C) 2013 Cavium Inc.
+ * Author: Vijaya Kumar K <vijaya.kumar@caviumnetworks.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/irq.h>
+#include <linux/kdebug.h>
+#include <linux/kgdb.h>
+#include <asm/traps.h>
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+        { "x0", 8, offsetof(struct pt_regs, regs[0])},
+        { "x1", 8, offsetof(struct pt_regs, regs[1])},
+        { "x2", 8, offsetof(struct pt_regs, regs[2])},
+        { "x3", 8, offsetof(struct pt_regs, regs[3])},
+        { "x4", 8, offsetof(struct pt_regs, regs[4])},
+        { "x5", 8, offsetof(struct pt_regs, regs[5])},
+        { "x6", 8, offsetof(struct pt_regs, regs[6])},
+        { "x7", 8, offsetof(struct pt_regs, regs[7])},
+        { "x8", 8, offsetof(struct pt_regs, regs[8])},
+        { "x9", 8, offsetof(struct pt_regs, regs[9])},
+        { "x10", 8, offsetof(struct pt_regs, regs[10])},
+        { "x11", 8, offsetof(struct pt_regs, regs[11])},
+        { "x12", 8, offsetof(struct pt_regs, regs[12])},
+        { "x13", 8, offsetof(struct pt_regs, regs[13])},
+        { "x14", 8, offsetof(struct pt_regs, regs[14])},
+        { "x15", 8, offsetof(struct pt_regs, regs[15])},
+        { "x16", 8, offsetof(struct pt_regs, regs[16])},
+        { "x17", 8, offsetof(struct pt_regs, regs[17])},
+        { "x18", 8, offsetof(struct pt_regs, regs[18])},
+        { "x19", 8, offsetof(struct pt_regs, regs[19])},
+        { "x20", 8, offsetof(struct pt_regs, regs[20])},
+        { "x21", 8, offsetof(struct pt_regs, regs[21])},
+        { "x22", 8, offsetof(struct pt_regs, regs[22])},
+        { "x23", 8, offsetof(struct pt_regs, regs[23])},
+        { "x24", 8, offsetof(struct pt_regs, regs[24])},
+        { "x25", 8, offsetof(struct pt_regs, regs[25])},
+        { "x26", 8, offsetof(struct pt_regs, regs[26])},
+        { "x27", 8, offsetof(struct pt_regs, regs[27])},
+        { "x28", 8, offsetof(struct pt_regs, regs[28])},
+        { "x29", 8, offsetof(struct pt_regs, regs[29])},
+        { "x30", 8, offsetof(struct pt_regs, regs[30])},
+        { "sp", 8, offsetof(struct pt_regs, sp)},
+        { "pc", 8, offsetof(struct pt_regs, pc)},
+        { "pstate", 8, offsetof(struct pt_regs, pstate)},
+        { "v0", 16, -1 },
+        { "v1", 16, -1 },
+        { "v2", 16, -1 },
+        { "v3", 16, -1 },
+        { "v4", 16, -1 },
+        { "v5", 16, -1 },
+        { "v6", 16, -1 },
+        { "v7", 16, -1 },
+        { "v8", 16, -1 },
+        { "v9", 16, -1 },
+        { "v10", 16, -1 },
+        { "v11", 16, -1 },
+        { "v12", 16, -1 },
+        { "v13", 16, -1 },
+        { "v14", 16, -1 },
+        { "v15", 16, -1 },
+        { "v16", 16, -1 },
+        { "v17", 16, -1 },
+        { "v18", 16, -1 },
+        { "v19", 16, -1 },
+        { "v20", 16, -1 },
+        { "v21", 16, -1 },
+        { "v22", 16, -1 },
+        { "v23", 16, -1 },
+        { "v24", 16, -1 },
+        { "v25", 16, -1 },
+        { "v26", 16, -1 },
+        { "v27", 16, -1 },
+        { "v28", 16, -1 },
+        { "v29", 16, -1 },
+        { "v30", 16, -1 },
+        { "v31", 16, -1 },
+        { "fpsr", 4, -1 },
+        { "fpcr", 4, -1 },
+};
+
+char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
+{
+        if (regno >= DBG_MAX_REG_NUM || regno < 0)
+                return NULL;
+
+        if (dbg_reg_def[regno].offset != -1)
+                memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
+                       dbg_reg_def[regno].size);
+        else
+                memset(mem, 0, dbg_reg_def[regno].size);
+        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;
+
+        if (dbg_reg_def[regno].offset != -1)
+                memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
+                       dbg_reg_def[regno].size);
+        return 0;
+}
+
+void
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
+{
+        struct pt_regs *thread_regs;
+
+        /* Initialize to zero */
+        memset((char *)gdb_regs, 0, NUMREGBYTES);
+        thread_regs = task_pt_regs(task);
+        memcpy((void *)gdb_regs, (void *)thread_regs->regs, GP_REG_BYTES);
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+        regs->pc = pc;
+}
+
+static int compiled_break;
+
+static void kgdb_arch_update_addr(struct pt_regs *regs,
+                                char *remcom_in_buffer)
+{
+        unsigned long addr;
+        char *ptr;
+
+        ptr = &remcom_in_buffer[1];
+        if (kgdb_hex2long(&ptr, &addr))
+                kgdb_arch_set_pc(regs, addr);
+        else if (compiled_break == 1)
+                kgdb_arch_set_pc(regs, regs->pc + 4);
+
+        compiled_break = 0;
+}
+
+int kgdb_arch_handle_exception(int exception_vector, int signo,
+                               int err_code, char *remcom_in_buffer,
+                               char *remcom_out_buffer,
+                               struct pt_regs *linux_regs)
+{
+        int err;
+
+        switch (remcom_in_buffer[0]) {
+        case 'D':
+        case 'k':
+                /*
+                 * Packet D (Detach), k (kill). No special handling
+                 * is required here. Handle same as c packet.
+                 */
+        case 'c':
+                /*
+                 * Packet c (Continue) to continue executing.
+                 * Set pc to required address.
+                 * Try to read optional parameter and set pc.
+                 * If this was a compiled breakpoint, we need to move
+                 * to the next instruction else we will just breakpoint
+                 * over and over again.
+                 */
+                kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
+                atomic_set(&kgdb_cpu_doing_single_step, -1);
+                kgdb_single_step =  0;
+
+                /*
+                 * Received continue command, disable single step
+                 */
+                if (kernel_active_single_step())
+                        kernel_disable_single_step();
+
+                err = 0;
+                break;
+        case 's':
+                /*
+                 * Update step address value with address passed
+                 * with step packet.
+                 * On debug exception return PC is copied to ELR
+                 * So just update PC.
+                 * If no step address is passed, resume from the address
+                 * pointed by PC. Do not update PC
+                 */
+                kgdb_arch_update_addr(linux_regs, remcom_in_buffer);
+                atomic_set(&kgdb_cpu_doing_single_step, raw_smp_processor_id());
+                kgdb_single_step =  1;
+
+                /*
+                 * Enable single step handling
+                 */
+                if (!kernel_active_single_step())
+                        kernel_enable_single_step(linux_regs);
+                err = 0;
+                break;
+        default:
+                err = -1;
+        }
+        return err;
+}
+
+static int kgdb_brk_fn(struct pt_regs *regs, unsigned int esr)
+{
+        kgdb_handle_exception(1, SIGTRAP, 0, regs);
+        return 0;
+}
+
+static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int esr)
+{
+        compiled_break = 1;
+        kgdb_handle_exception(1, SIGTRAP, 0, regs);
+
+        return 0;
+}
+
+static int kgdb_step_brk_fn(struct pt_regs *regs, unsigned int esr)
+{
+        kgdb_handle_exception(1, SIGTRAP, 0, regs);
+        return 0;
+}
+
+static struct break_hook kgdb_brkpt_hook = {
+        .esr_mask       = 0xffffffff,
+        .esr_val        = DBG_ESR_VAL_BRK(KGDB_DYN_DGB_BRK_IMM),
+        .fn             = kgdb_brk_fn
+};
+
+static struct break_hook kgdb_compiled_brkpt_hook = {
+        .esr_mask       = 0xffffffff,
+        .esr_val        = DBG_ESR_VAL_BRK(KDBG_COMPILED_DBG_BRK_IMM),
+        .fn             = kgdb_compiled_brk_fn
+};
+
+static struct step_hook kgdb_step_hook = {
+        .fn             = kgdb_step_brk_fn
+};
+
+static void kgdb_call_nmi_hook(void *ignored)
+{
+        kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+        local_irq_enable();
+        smp_call_function(kgdb_call_nmi_hook, NULL, 0);
+        local_irq_disable();
+}
+
+static int __kgdb_notify(struct die_args *args, unsigned long cmd)
+{
+        struct pt_regs *regs = args->regs;
+
+        if (kgdb_handle_exception(1, args->signr, cmd, regs))
+                return NOTIFY_DONE;
+        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,
+        /*
+         * Want to be lowest priority
+         */
+        .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)
+{
+        int ret = register_die_notifier(&kgdb_notifier);
+
+        if (ret != 0)
+                return ret;
+
+        register_break_hook(&kgdb_brkpt_hook);
+        register_break_hook(&kgdb_compiled_brkpt_hook);
+        register_step_hook(&kgdb_step_hook);
+        return 0;
+}
+
+/*
+ * 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_break_hook(&kgdb_brkpt_hook);
+        unregister_break_hook(&kgdb_compiled_brkpt_hook);
+        unregister_step_hook(&kgdb_step_hook);
+        unregister_die_notifier(&kgdb_notifier);
+}
+
+/*
+ * ARM instructions are always in LE.
+ * Break instruction is encoded in LE format
+ */
+struct kgdb_arch arch_kgdb_ops = {
+        .gdb_bpt_instr = {
+                KGDB_DYN_BRK_INS_BYTE0,
+                KGDB_DYN_BRK_INS_BYTE1,
+                KGDB_DYN_BRK_INS_BYTE2,
+                KGDB_DYN_BRK_INS_BYTE3,
+        }
+};