--- /dev/null
+/*
+ * Copyright 2013 Tilera Corporation. 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
+ * as published by the Free Software Foundation, version 2.
+ *
+ * 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, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * TILE-Gx KGDB support.
+ */
+
+#include <linux/ptrace.h>
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <asm/cacheflush.h>
+
+static tile_bundle_bits singlestep_insn = TILEGX_BPT_BUNDLE | DIE_SSTEPBP;
+static unsigned long stepped_addr;
+static tile_bundle_bits stepped_instr;
+
+struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
+ { "r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0])},
+ { "r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1])},
+ { "r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2])},
+ { "r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3])},
+ { "r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4])},
+ { "r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5])},
+ { "r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6])},
+ { "r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7])},
+ { "r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8])},
+ { "r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9])},
+ { "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10])},
+ { "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11])},
+ { "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12])},
+ { "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13])},
+ { "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14])},
+ { "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15])},
+ { "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16])},
+ { "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17])},
+ { "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18])},
+ { "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19])},
+ { "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20])},
+ { "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21])},
+ { "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22])},
+ { "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23])},
+ { "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24])},
+ { "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25])},
+ { "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26])},
+ { "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27])},
+ { "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28])},
+ { "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29])},
+ { "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30])},
+ { "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31])},
+ { "r32", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[32])},
+ { "r33", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[33])},
+ { "r34", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[34])},
+ { "r35", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[35])},
+ { "r36", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[36])},
+ { "r37", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[37])},
+ { "r38", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[38])},
+ { "r39", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[39])},
+ { "r40", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[40])},
+ { "r41", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[41])},
+ { "r42", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[42])},
+ { "r43", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[43])},
+ { "r44", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[44])},
+ { "r45", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[45])},
+ { "r46", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[46])},
+ { "r47", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[47])},
+ { "r48", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[48])},
+ { "r49", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[49])},
+ { "r50", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[50])},
+ { "r51", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[51])},
+ { "r52", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[52])},
+ { "tp", GDB_SIZEOF_REG, offsetof(struct pt_regs, tp)},
+ { "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, sp)},
+ { "lr", GDB_SIZEOF_REG, offsetof(struct pt_regs, lr)},
+ { "sn", GDB_SIZEOF_REG, -1},
+ { "idn0", GDB_SIZEOF_REG, -1},
+ { "idn1", GDB_SIZEOF_REG, -1},
+ { "udn0", GDB_SIZEOF_REG, -1},
+ { "udn1", GDB_SIZEOF_REG, -1},
+ { "udn2", GDB_SIZEOF_REG, -1},
+ { "udn3", GDB_SIZEOF_REG, -1},
+ { "zero", GDB_SIZEOF_REG, -1},
+ { "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, pc)},
+ { "faultnum", GDB_SIZEOF_REG, offsetof(struct pt_regs, faultnum)},
+};
+
+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;
+}
+
+/*
+ * Similar to pt_regs_to_gdb_regs() except that process is sleeping and so
+ * we may not be able to get all the info.
+ */
+void
+sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
+{
+ int reg;
+ struct pt_regs *thread_regs;
+ unsigned long *ptr = gdb_regs;
+
+ if (task == NULL)
+ return;
+
+ /* Initialize to zero. */
+ memset(gdb_regs, 0, NUMREGBYTES);
+
+ thread_regs = task_pt_regs(task);
+ for (reg = 0; reg <= TREG_LAST_GPR; reg++)
+ *(ptr++) = thread_regs->regs[reg];
+
+ gdb_regs[TILEGX_PC_REGNUM] = thread_regs->pc;
+ gdb_regs[TILEGX_FAULTNUM_REGNUM] = thread_regs->faultnum;
+}
+
+void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
+{
+ regs->pc = pc;
+}
+
+static void kgdb_call_nmi_hook(void *ignored)
+{
+ kgdb_nmicallback(raw_smp_processor_id(), NULL);
+}
+
+void kgdb_roundup_cpus(unsigned long flags)
+{
+ local_irq_enable();
+ smp_call_function(kgdb_call_nmi_hook, NULL, 0);
+ local_irq_disable();
+}
+
+/*
+ * Convert a kernel address to the writable kernel text mapping.
+ */
+static unsigned long writable_address(unsigned long addr)
+{
+ unsigned long ret = 0;
+
+ if (core_kernel_text(addr))
+ ret = addr - MEM_SV_START + PAGE_OFFSET;
+ else if (is_module_text_address(addr))
+ ret = addr;
+ else
+ pr_err("Unknown virtual address 0x%lx\n", addr);
+
+ return ret;
+}
+
+/*
+ * Calculate the new address for after a step.
+ */
+static unsigned long get_step_address(struct pt_regs *regs)
+{
+ int src_reg;
+ int jump_off;
+ int br_off;
+ unsigned long addr;
+ unsigned int opcode;
+ tile_bundle_bits bundle;
+
+ /* Move to the next instruction by default. */
+ addr = regs->pc + TILEGX_BUNDLE_SIZE_IN_BYTES;
+ bundle = *(unsigned long *)instruction_pointer(regs);
+
+ /* 0: X mode, Otherwise: Y mode. */
+ if (bundle & TILEGX_BUNDLE_MODE_MASK) {
+ if (get_Opcode_Y1(bundle) == RRR_1_OPCODE_Y1 &&
+ get_RRROpcodeExtension_Y1(bundle) ==
+ UNARY_RRR_1_OPCODE_Y1) {
+ opcode = get_UnaryOpcodeExtension_Y1(bundle);
+
+ switch (opcode) {
+ case JALR_UNARY_OPCODE_Y1:
+ case JALRP_UNARY_OPCODE_Y1:
+ case JR_UNARY_OPCODE_Y1:
+ case JRP_UNARY_OPCODE_Y1:
+ src_reg = get_SrcA_Y1(bundle);
+ dbg_get_reg(src_reg, &addr, regs);
+ break;
+ }
+ }
+ } else if (get_Opcode_X1(bundle) == RRR_0_OPCODE_X1) {
+ if (get_RRROpcodeExtension_X1(bundle) ==
+ UNARY_RRR_0_OPCODE_X1) {
+ opcode = get_UnaryOpcodeExtension_X1(bundle);
+
+ switch (opcode) {
+ case JALR_UNARY_OPCODE_X1:
+ case JALRP_UNARY_OPCODE_X1:
+ case JR_UNARY_OPCODE_X1:
+ case JRP_UNARY_OPCODE_X1:
+ src_reg = get_SrcA_X1(bundle);
+ dbg_get_reg(src_reg, &addr, regs);
+ break;
+ }
+ }
+ } else if (get_Opcode_X1(bundle) == JUMP_OPCODE_X1) {
+ opcode = get_JumpOpcodeExtension_X1(bundle);
+
+ switch (opcode) {
+ case JAL_JUMP_OPCODE_X1:
+ case J_JUMP_OPCODE_X1:
+ jump_off = sign_extend(get_JumpOff_X1(bundle), 27);
+ addr = regs->pc +
+ (jump_off << TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES);
+ break;
+ }
+ } else if (get_Opcode_X1(bundle) == BRANCH_OPCODE_X1) {
+ br_off = 0;
+ opcode = get_BrType_X1(bundle);
+
+ switch (opcode) {
+ case BEQZT_BRANCH_OPCODE_X1:
+ case BEQZ_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) == 0)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BGEZT_BRANCH_OPCODE_X1:
+ case BGEZ_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) >= 0)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BGTZT_BRANCH_OPCODE_X1:
+ case BGTZ_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) > 0)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BLBCT_BRANCH_OPCODE_X1:
+ case BLBC_BRANCH_OPCODE_X1:
+ if (!(get_SrcA_X1(bundle) & 1))
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BLBST_BRANCH_OPCODE_X1:
+ case BLBS_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) & 1)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BLEZT_BRANCH_OPCODE_X1:
+ case BLEZ_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) <= 0)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BLTZT_BRANCH_OPCODE_X1:
+ case BLTZ_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) < 0)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ case BNEZT_BRANCH_OPCODE_X1:
+ case BNEZ_BRANCH_OPCODE_X1:
+ if (get_SrcA_X1(bundle) != 0)
+ br_off = get_BrOff_X1(bundle);
+ break;
+ }
+
+ if (br_off != 0) {
+ br_off = sign_extend(br_off, 17);
+ addr = regs->pc +
+ (br_off << TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES);
+ }
+ }
+
+ return addr;
+}
+
+/*
+ * Replace the next instruction after the current instruction with a
+ * breakpoint instruction.
+ */
+static void do_single_step(struct pt_regs *regs)
+{
+ unsigned long addr_wr;
+
+ /* Determine where the target instruction will send us to. */
+ stepped_addr = get_step_address(regs);
+ probe_kernel_read((char *)&stepped_instr, (char *)stepped_addr,
+ BREAK_INSTR_SIZE);
+
+ addr_wr = writable_address(stepped_addr);
+ probe_kernel_write((char *)addr_wr, (char *)&singlestep_insn,
+ BREAK_INSTR_SIZE);
+ smp_wmb();
+ flush_icache_range(stepped_addr, stepped_addr + BREAK_INSTR_SIZE);
+}
+
+static void undo_single_step(struct pt_regs *regs)
+{
+ unsigned long addr_wr;
+
+ if (stepped_instr == 0)
+ return;
+
+ addr_wr = writable_address(stepped_addr);
+ probe_kernel_write((char *)addr_wr, (char *)&stepped_instr,
+ BREAK_INSTR_SIZE);
+ stepped_instr = 0;
+ smp_wmb();
+ flush_icache_range(stepped_addr, stepped_addr + BREAK_INSTR_SIZE);
+}
+
+/*
+ * Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
+ * then try to fall into the debugger.
+ */
+static int
+kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
+{
+ int ret;
+ unsigned long flags;
+ struct die_args *args = (struct die_args *)ptr;
+ struct pt_regs *regs = args->regs;
+
+#ifdef CONFIG_KPROBES
+ /*
+ * Return immediately if the kprobes fault notifier has set
+ * DIE_PAGE_FAULT.
+ */
+ if (cmd == DIE_PAGE_FAULT)
+ return NOTIFY_DONE;
+#endif /* CONFIG_KPROBES */
+
+ switch (cmd) {
+ case DIE_BREAK:
+ case DIE_COMPILED_BPT:
+ break;
+ case DIE_SSTEPBP:
+ local_irq_save(flags);
+ kgdb_handle_exception(0, SIGTRAP, 0, regs);
+ local_irq_restore(flags);
+ return NOTIFY_STOP;
+ default:
+ /* Userspace events, ignore. */
+ if (user_mode(regs))
+ return NOTIFY_DONE;
+ }
+
+ local_irq_save(flags);
+ ret = kgdb_handle_exception(args->trapnr, args->signr, args->err, regs);
+ local_irq_restore(flags);
+ if (ret)
+ return NOTIFY_DONE;
+
+ return NOTIFY_STOP;
+}
+
+static struct notifier_block kgdb_notifier = {
+ .notifier_call = kgdb_notify,
+};
+
+/*
+ * 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.
+ */
+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 address;
+
+ /* Undo any stepping we may have done. */
+ undo_single_step(regs);
+
+ switch (remcom_in_buffer[0]) {
+ case 'c':
+ case 's':
+ case 'D':
+ case 'k':
+ /*
+ * Try to read optional parameter, pc unchanged if no parm.
+ * If this was a compiled-in breakpoint, we need to move
+ * to the next instruction or we will just breakpoint
+ * over and over again.
+ */
+ ptr = &remcom_in_buffer[1];
+ if (kgdb_hex2long(&ptr, &address))
+ regs->pc = address;
+ else if (*(unsigned long *)regs->pc == compiled_bpt)
+ regs->pc += BREAK_INSTR_SIZE;
+
+ if (remcom_in_buffer[0] == 's') {
+ do_single_step(regs);
+ kgdb_single_step = 1;
+ atomic_set(&kgdb_cpu_doing_single_step,
+ raw_smp_processor_id());
+ } else
+ atomic_set(&kgdb_cpu_doing_single_step, -1);
+
+ return 0;
+ }
+
+ return -1; /* this means that we do not want to exit from the handler */
+}
+
+struct kgdb_arch arch_kgdb_ops;
+
+/*
+ * kgdb_arch_init - Perform any architecture specific initalization.
+ *
+ * This function will handle the initalization of any architecture
+ * specific callbacks.
+ */
+int kgdb_arch_init(void)
+{
+ tile_bundle_bits bundle = TILEGX_BPT_BUNDLE;
+
+ memcpy(arch_kgdb_ops.gdb_bpt_instr, &bundle, BREAK_INSTR_SIZE);
+ 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);
+}
+
+int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt)
+{
+ int err;
+ unsigned long addr_wr = writable_address(bpt->bpt_addr);
+
+ if (addr_wr == 0)
+ return -1;
+
+ err = probe_kernel_read(bpt->saved_instr, (char *)bpt->bpt_addr,
+ BREAK_INSTR_SIZE);
+ if (err)
+ return err;
+
+ err = probe_kernel_write((char *)addr_wr, arch_kgdb_ops.gdb_bpt_instr,
+ BREAK_INSTR_SIZE);
+ smp_wmb();
+ flush_icache_range((unsigned long)bpt->bpt_addr,
+ (unsigned long)bpt->bpt_addr + BREAK_INSTR_SIZE);
+ return err;
+}
+
+int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt)
+{
+ int err;
+ unsigned long addr_wr = writable_address(bpt->bpt_addr);
+
+ if (addr_wr == 0)
+ return -1;
+
+ err = probe_kernel_write((char *)addr_wr, (char *)bpt->saved_instr,
+ BREAK_INSTR_SIZE);
+ smp_wmb();
+ flush_icache_range((unsigned long)bpt->bpt_addr,
+ (unsigned long)bpt->bpt_addr + BREAK_INSTR_SIZE);
+ return err;
+}
projects / karo-tx-linux.git / commitdiff