1 // SPDX-License-Identifier: GPL-2.0-only
10  * HW_breakpoint: a unified kernel/user-space hardware breakpoint facility,
13 #define pr_fmt(fmt) "hw-breakpoint: " fmt
150 	/* We don't support the memory-mapped interface. */  in debug_arch_supported()
215 	return core_has_mismatch_brps() ? brps - 1 : brps;  in get_num_brps()
253 		return -ENODEV;  in enable_monitor_mode()
261 		return -EPERM;  in enable_monitor_mode()
289  * Check if 8-bit byte-address select is available.
295 	struct arch_hw_breakpoint_ctrl ctrl;  in get_max_wp_len()  local
301 	memset(&ctrl, 0, sizeof(ctrl));  in get_max_wp_len()
302 	ctrl.len = ARM_BREAKPOINT_LEN_8;  in get_max_wp_len()
303 	ctrl_reg = encode_ctrl_reg(ctrl);  in get_max_wp_len()
327 	u32 addr, ctrl;  in arch_install_hw_breakpoint()  local
329 	addr = info->address;  in arch_install_hw_breakpoint()
330 	ctrl = encode_ctrl_reg(info->ctrl) | 0x1;  in arch_install_hw_breakpoint()
332 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {  in arch_install_hw_breakpoint()
357 		return -EBUSY;  in arch_install_hw_breakpoint()
361 	if (info->step_ctrl.enabled) {  in arch_install_hw_breakpoint()
362 		addr = info->trigger & ~0x3;  in arch_install_hw_breakpoint()
363 		ctrl = encode_ctrl_reg(info->step_ctrl);  in arch_install_hw_breakpoint()
364 		if (info->ctrl.type != ARM_BREAKPOINT_EXECUTE) {  in arch_install_hw_breakpoint()
375 	write_wb_reg(ctrl_base + i, ctrl);  in arch_install_hw_breakpoint()
385 	if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {  in arch_uninstall_hw_breakpoint()
413 	if (info->ctrl.type != ARM_BREAKPOINT_EXECUTE &&  in arch_uninstall_hw_breakpoint()
414 	    info->step_ctrl.enabled) {  in arch_uninstall_hw_breakpoint()
450 	unsigned int len;  in arch_check_bp_in_kernelspace()  local
453 	va = hw->address;  in arch_check_bp_in_kernelspace()
454 	len = get_hbp_len(hw->ctrl.len);  in arch_check_bp_in_kernelspace()
456 	return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);  in arch_check_bp_in_kernelspace()
464 int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,  in arch_bp_generic_fields()  argument
468 	switch (ctrl.type) {  in arch_bp_generic_fields()
482 		return -EINVAL;  in arch_bp_generic_fields()
485 	/* Len */  in arch_bp_generic_fields()
486 	switch (ctrl.len) {  in arch_bp_generic_fields()
500 		return -EINVAL;  in arch_bp_generic_fields()
514 	switch (attr->bp_type) {  in arch_build_bp_info()
516 		hw->ctrl.type = ARM_BREAKPOINT_EXECUTE;  in arch_build_bp_info()
519 		hw->ctrl.type = ARM_BREAKPOINT_LOAD;  in arch_build_bp_info()
522 		hw->ctrl.type = ARM_BREAKPOINT_STORE;  in arch_build_bp_info()
525 		hw->ctrl.type = ARM_BREAKPOINT_LOAD | ARM_BREAKPOINT_STORE;  in arch_build_bp_info()
528 		return -EINVAL;  in arch_build_bp_info()
531 	/* Len */  in arch_build_bp_info()
532 	switch (attr->bp_len) {  in arch_build_bp_info()
534 		hw->ctrl.len = ARM_BREAKPOINT_LEN_1;  in arch_build_bp_info()
537 		hw->ctrl.len = ARM_BREAKPOINT_LEN_2;  in arch_build_bp_info()
540 		hw->ctrl.len = ARM_BREAKPOINT_LEN_4;  in arch_build_bp_info()
543 		hw->ctrl.len = ARM_BREAKPOINT_LEN_8;  in arch_build_bp_info()
544 		if ((hw->ctrl.type != ARM_BREAKPOINT_EXECUTE)  in arch_build_bp_info()
549 		return -EINVAL;  in arch_build_bp_info()
558 	if (hw->ctrl.type == ARM_BREAKPOINT_EXECUTE &&  in arch_build_bp_info()
559 	    hw->ctrl.len != ARM_BREAKPOINT_LEN_2 &&  in arch_build_bp_info()
560 	    hw->ctrl.len != ARM_BREAKPOINT_LEN_4)  in arch_build_bp_info()
561 		return -EINVAL;  in arch_build_bp_info()
564 	hw->address = attr->bp_addr;  in arch_build_bp_info()
567 	hw->ctrl.privilege = ARM_BREAKPOINT_USER;  in arch_build_bp_info()
569 		hw->ctrl.privilege |= ARM_BREAKPOINT_PRIV;  in arch_build_bp_info()
572 	hw->ctrl.enabled = !attr->disabled;  in arch_build_bp_info()
575 	hw->ctrl.mismatch = 0;  in arch_build_bp_info()
581  * Validate the arch-specific HW Breakpoint register settings.
592 		return -ENODEV;  in hw_breakpoint_arch_parse()
600 	if (hw->ctrl.len == ARM_BREAKPOINT_LEN_8)  in hw_breakpoint_arch_parse()
602 	offset = hw->address & alignment_mask;  in hw_breakpoint_arch_parse()
610 		if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)  in hw_breakpoint_arch_parse()
615 		if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)  in hw_breakpoint_arch_parse()
619 		ret = -EINVAL;  in hw_breakpoint_arch_parse()
623 	hw->address &= ~alignment_mask;  in hw_breakpoint_arch_parse()
624 	hw->ctrl.len <<= offset;  in hw_breakpoint_arch_parse()
628 		 * Mismatch breakpoints are required for single-stepping  in hw_breakpoint_arch_parse()
632 			return -EINVAL;  in hw_breakpoint_arch_parse()
636 			return -EPERM;  in hw_breakpoint_arch_parse()
639 		 * Per-cpu breakpoints are not supported by our stepping  in hw_breakpoint_arch_parse()
642 		if (!bp->hw.target)  in hw_breakpoint_arch_parse()
643 			return -EINVAL;  in hw_breakpoint_arch_parse()
650 		    (hw->ctrl.type == ARM_BREAKPOINT_LOAD ||  in hw_breakpoint_arch_parse()
651 		     hw->ctrl.type == ARM_BREAKPOINT_STORE))  in hw_breakpoint_arch_parse()
652 			return -EINVAL;  in hw_breakpoint_arch_parse()
660  * Enable/disable single-stepping over the breakpoint bp at address addr.
667 	info->step_ctrl.mismatch  = 1;  in enable_single_step()
668 	info->step_ctrl.len	  = ARM_BREAKPOINT_LEN_4;  in enable_single_step()
669 	info->step_ctrl.type	  = ARM_BREAKPOINT_EXECUTE;  in enable_single_step()
670 	info->step_ctrl.privilege = info->ctrl.privilege;  in enable_single_step()
671 	info->step_ctrl.enabled	  = 1;  in enable_single_step()
672 	info->trigger		  = addr;  in enable_single_step()
679 	counter_arch_bp(bp)->step_ctrl.enabled = 0;  in disable_single_step()
690 	struct arch_hw_breakpoint_ctrl ctrl;  in watchpoint_handler()  local
711 			info->trigger = wp->attr.bp_addr;  in watchpoint_handler()
713 			if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)  in watchpoint_handler()
725 			decode_ctrl_reg(ctrl_reg, &ctrl);  in watchpoint_handler()
726 			if (!((1 << (addr & alignment_mask)) & ctrl.len))  in watchpoint_handler()
738 			info->trigger = addr;  in watchpoint_handler()
741 		pr_debug("watchpoint fired: address = 0x%x\n", info->trigger);  in watchpoint_handler()
746 		 * mismatch breakpoint so we can single-step over the  in watchpoint_handler()
774 		if (!info->step_ctrl.enabled)  in watchpoint_single_step_handler()
779 		 * single-step.  in watchpoint_single_step_handler()
781 		if (info->trigger != pc)  in watchpoint_single_step_handler()
795 	struct arch_hw_breakpoint_ctrl ctrl;  in breakpoint_handler()  local
800 	addr = regs->ARM_pc;  in breakpoint_handler()
820 		decode_ctrl_reg(ctrl_reg, &ctrl);  in breakpoint_handler()
821 		if ((1 << (addr & 0x3)) & ctrl.len) {  in breakpoint_handler()
822 			info->trigger = addr;  in breakpoint_handler()
825 			if (!bp->overflow_handler)  in breakpoint_handler()
832 		if (info->step_ctrl.enabled)  in breakpoint_handler()
838 	/* Handle any pending watchpoint single-step breakpoints. */  in breakpoint_handler()
881  * One-time initialisation.
929 	 * can be maintained across low-power modes without leaving the debug  in reset_ctrl_regs()
942 		 * Ensure sticky power-down is clear (i.e. debug logic is  in reset_ctrl_regs()
947 			err = -EPERM;  in reset_ctrl_regs()
958 			err = -EPERM;  in reset_ctrl_regs()
976 	 * Clear any configured vector-catch events before  in reset_ctrl_regs()