Merge "arm64: kernel: refactor code to install/uninstall breakpoints" (581a039d) · Commits · e / devices / android_kernel_sony_msm8994_rework

arch/arm64/kernel/hw_breakpoint.c

+88 −54

Original line number	Diff line number	Diff line
		@@ -169,15 +169,63 @@ static enum debug_el debug_exception_level(int privilege)
		}
		}

		/*
		* Install a perf counter breakpoint.
		enum hw_breakpoint_ops {
		HW_BREAKPOINT_INSTALL,
		HW_BREAKPOINT_UNINSTALL
		};

		/**
		* hw_breakpoint_slot_setup - Find and setup a perf slot according to
		* operations
		*
		* @slots: pointer to array of slots
		* @max_slots: max number of slots
		* @bp: perf_event to setup
		* @ops: operation to be carried out on the slot
		*
		* Return:
		* slot index on success
		* -ENOSPC if no slot is available/matches
		* -EINVAL on wrong operations parameter
		*/
		int arch_install_hw_breakpoint(struct perf_event *bp)
		static int hw_breakpoint_slot_setup(struct perf_event **slots, int max_slots,
		struct perf_event *bp,
		enum hw_breakpoint_ops ops)
		{
		int i;
		struct perf_event **slot;

		for (i = 0; i < max_slots; ++i) {
		slot = &slots[i];
		switch (ops) {
		case HW_BREAKPOINT_INSTALL:
		if (!*slot) {
		*slot = bp;
		return i;
		}
		break;
		case HW_BREAKPOINT_UNINSTALL:
		if (*slot == bp) {
		*slot = NULL;
		return i;
		}
		break;
		default:
		pr_warn_once("Unhandled hw breakpoint ops %d\n", ops);
		return -EINVAL;
		}
		}
		return -ENOSPC;
		}

		static int hw_breakpoint_control(struct perf_event *bp,
		enum hw_breakpoint_ops ops)
		{
		struct arch_hw_breakpoint *info = counter_arch_bp(bp);
		struct perf_event slot, slots;
		struct perf_event **slots;
		struct debug_info *debug_info = &current->thread.debug;
		int i, max_slots, ctrl_reg, val_reg, reg_enable;
		enum debug_el dbg_el = debug_exception_level(info->ctrl.privilege);
		u32 ctrl;

		if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
		@@ -196,67 +244,53 @@ int arch_install_hw_breakpoint(struct perf_event *bp)
		reg_enable = !debug_info->wps_disabled;
		}

		for (i = 0; i < max_slots; ++i) {
		slot = &slots[i];
		i = hw_breakpoint_slot_setup(slots, max_slots, bp, ops);

		if (!*slot) {
		*slot = bp;
		break;
		}
		}
		if (WARN_ONCE(i < 0, "Can't find any breakpoint slot"))
		return i;

		if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot"))
		return -ENOSPC;

		/* Ensure debug monitors are enabled at the correct exception level. */
		enable_debug_monitors(debug_exception_level(info->ctrl.privilege));
		switch (ops) {
		case HW_BREAKPOINT_INSTALL:
		/*
		* Ensure debug monitors are enabled at the correct exception
		* level.
		*/
		enable_debug_monitors(dbg_el);

		/* Setup the address register. */
		write_wb_reg(val_reg, i, info->address);

		/* Setup the control register. */
		ctrl = encode_ctrl_reg(info->ctrl);
		write_wb_reg(ctrl_reg, i, reg_enable ? ctrl \| 0x1 : ctrl & ~0x1);
		write_wb_reg(ctrl_reg, i,
		reg_enable ? ctrl \| 0x1 : ctrl & ~0x1);
		break;
		case HW_BREAKPOINT_UNINSTALL:
		/* Reset the control register. */
		write_wb_reg(ctrl_reg, i, 0);

		return 0;
		/*
		* Release the debug monitors for the correct exception
		* level.
		*/
		disable_debug_monitors(dbg_el);
		break;
		}

		void arch_uninstall_hw_breakpoint(struct perf_event *bp)
		{
		struct arch_hw_breakpoint *info = counter_arch_bp(bp);
		struct perf_event slot, slots;
		int i, max_slots, base;

		if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
		/* Breakpoint */
		base = AARCH64_DBG_REG_BCR;
		slots = this_cpu_ptr(bp_on_reg);
		max_slots = core_num_brps;
		} else {
		/* Watchpoint */
		base = AARCH64_DBG_REG_WCR;
		slots = this_cpu_ptr(wp_on_reg);
		max_slots = core_num_wrps;
		return 0;
		}

		/* Remove the breakpoint. */
		for (i = 0; i < max_slots; ++i) {
		slot = &slots[i];

		if (*slot == bp) {
		*slot = NULL;
		break;
		}
		/*
		* Install a perf counter breakpoint.
		*/
		int arch_install_hw_breakpoint(struct perf_event *bp)
		{
		return hw_breakpoint_control(bp, HW_BREAKPOINT_INSTALL);
		}

		if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot"))
		return;

		/* Reset the control register. */
		write_wb_reg(base, i, 0);

		/* Release the debug monitors for the correct exception level. */
		disable_debug_monitors(debug_exception_level(info->ctrl.privilege));
		void arch_uninstall_hw_breakpoint(struct perf_event *bp)
		{
		hw_breakpoint_control(bp, HW_BREAKPOINT_UNINSTALL);
		}

		static int get_hbp_len(u8 hbp_len)