drivers/misc/vcpu_stall_detector.c

1 // SPDX-License-Identifier: GPL-2.0-only
3 // VCPU stall detector.
46 /* The vcpu stall configuration structure which applies to all the CPUs */
49 #define vcpu_stall_reg_write(vcpu, reg, value)				\  argument
52 		       (vcpu) * VCPU_STALL_REG_LEN + (reg)))
62 	/* Reload the stall detector counter register every  in vcpu_stall_detect_timer_fn()
85 	struct hrtimer *vcpu_hrtimer = &vcpu_stall_detector->vcpu_hrtimer;  in start_stall_detector_cpu()
90 	/* Compute the number of ticks required for the stall detector  in start_stall_detector_cpu()
98 	/* Enable the internal clock and start the stall detector */  in start_stall_detector_cpu()
101 	/* Pet the stall detector at half of its expiration timeout  in start_stall_detector_cpu()
108 	vcpu_hrtimer->function = vcpu_stall_detect_timer_fn;  in start_stall_detector_cpu()
109 	vcpu_stall_detector->is_initialized = true;  in start_stall_detector_cpu()
122 	if (!vcpu_stall_detector->is_initialized)  in stop_stall_detector_cpu()
125 	/* Disable the stall detector for the current CPU */  in stop_stall_detector_cpu()
126 	hrtimer_cancel(&vcpu_stall_detector->vcpu_hrtimer);  in stop_stall_detector_cpu()
128 	vcpu_stall_detector->is_initialized = false;  in stop_stall_detector_cpu()
140 	struct device_node *np = pdev->dev.of_node;  in vcpu_stall_detect_probe()
142 	vcpu_stall_detectors = devm_alloc_percpu(&pdev->dev,  in vcpu_stall_detect_probe()
145 		return -ENOMEM;  in vcpu_stall_detect_probe()
149 		dev_err(&pdev->dev, "Failed to get memory resource\n");  in vcpu_stall_detect_probe()
153 	if (!of_property_read_u32(np, "clock-frequency", &clock_freq_hz)) {  in vcpu_stall_detect_probe()
156 			dev_warn(&pdev->dev, "clk out of range\n");  in vcpu_stall_detect_probe()
161 	if (!of_property_read_u32(np, "timeout-sec", &stall_timeout_sec)) {  in vcpu_stall_detect_probe()
164 			dev_warn(&pdev->dev, "stall timeout out of range\n");  in vcpu_stall_detect_probe()
180 		dev_err(&pdev->dev, "failed to install cpu hotplug");  in vcpu_stall_detect_probe()
203 	{ .compatible = "qemu,vcpu-stall-detector", },
222 MODULE_DESCRIPTION("VCPU stall detector");