drivers/misc/vcpu_stall_detector.c

1 // SPDX-License-Identifier: GPL-2.0-only
3 // VCPU stall detector.
47 /* The vcpu stall configuration structure which applies to all the CPUs */
50 #define vcpu_stall_reg_write(vcpu, reg, value)				\  argument
53 		       (vcpu) * VCPU_STALL_REG_LEN + (reg)))
63 	/* Reload the stall detector counter register every  in vcpu_stall_detect_timer_fn()
83 	panic("vCPU stall detector");  in vcpu_stall_detector_irq()
92 	struct hrtimer *vcpu_hrtimer = &vcpu_stall_detector->vcpu_hrtimer;  in start_stall_detector_cpu()
97 	/* Compute the number of ticks required for the stall detector  in start_stall_detector_cpu()
105 	/* Enable the internal clock and start the stall detector */  in start_stall_detector_cpu()
108 	/* Pet the stall detector at half of its expiration timeout  in start_stall_detector_cpu()
115 	vcpu_hrtimer->function = vcpu_stall_detect_timer_fn;  in start_stall_detector_cpu()
116 	vcpu_stall_detector->is_initialized = true;  in start_stall_detector_cpu()
129 	if (!vcpu_stall_detector->is_initialized)  in stop_stall_detector_cpu()
132 	/* Disable the stall detector for the current CPU */  in stop_stall_detector_cpu()
133 	hrtimer_cancel(&vcpu_stall_detector->vcpu_hrtimer);  in stop_stall_detector_cpu()
135 	vcpu_stall_detector->is_initialized = false;  in stop_stall_detector_cpu()
147 	struct device_node *np = pdev->dev.of_node;  in vcpu_stall_detect_probe()
149 	vcpu_stall_detectors = devm_alloc_percpu(&pdev->dev,  in vcpu_stall_detect_probe()
152 		return -ENOMEM;  in vcpu_stall_detect_probe()
156 		dev_err(&pdev->dev, "Failed to get memory resource\n");  in vcpu_stall_detect_probe()
160 	if (!of_property_read_u32(np, "clock-frequency", &clock_freq_hz)) {  in vcpu_stall_detect_probe()
163 			dev_warn(&pdev->dev, "clk out of range\n");  in vcpu_stall_detect_probe()
168 	if (!of_property_read_u32(np, "timeout-sec", &stall_timeout_sec)) {  in vcpu_stall_detect_probe()
171 			dev_warn(&pdev->dev, "stall timeout out of range\n");  in vcpu_stall_detect_probe()
180 		.ppi_irq		= -1,  in vcpu_stall_detect_probe()
200 		dev_err(&pdev->dev, "failed to install cpu hotplug");  in vcpu_stall_detect_probe()
228 	{ .compatible = "qemu,vcpu-stall-detector", },
247 MODULE_DESCRIPTION("VCPU stall detector");