Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

1 files changed, 270 insertions, 0 deletions

diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c
new file mode 100644
index 000000000..3674bceda
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-activity.c
@@ -0,0 +1,270 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Activity LED trigger
+ *
+ * Copyright (C) 2017 Willy Tarreau <w@1wt.eu>
+ * Partially based on Atsushi Nemoto's ledtrig-heartbeat.c.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/kernel_stat.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/panic_notifier.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/timer.h>
+#include "../leds.h"
+
+static int panic_detected;
+
+struct activity_data {
+	struct timer_list timer;
+	struct led_classdev *led_cdev;
+	u64 last_used;
+	u64 last_boot;
+	int time_left;
+	int state;
+	int invert;
+};
+
+static void led_activity_function(struct timer_list *t)
+{
+	struct activity_data *activity_data = timer_container_of(activity_data,
+								 t, timer);
+	struct led_classdev *led_cdev = activity_data->led_cdev;
+	unsigned int target;
+	unsigned int usage;
+	int delay;
+	u64 curr_used;
+	u64 curr_boot;
+	s32 diff_used;
+	s32 diff_boot;
+	int cpus;
+	int i;
+
+	if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE, &led_cdev->work_flags))
+		led_cdev->blink_brightness = led_cdev->new_blink_brightness;
+
+	if (unlikely(panic_detected)) {
+		/* full brightness in case of panic */
+		led_set_brightness_nosleep(led_cdev, led_cdev->blink_brightness);
+		return;
+	}
+
+	cpus = 0;
+	curr_used = 0;
+
+	for_each_possible_cpu(i) {
+		struct kernel_cpustat kcpustat;
+
+		kcpustat_cpu_fetch(&kcpustat, i);
+
+		curr_used += kcpustat.cpustat[CPUTIME_USER]
+			  +  kcpustat.cpustat[CPUTIME_NICE]
+			  +  kcpustat.cpustat[CPUTIME_SYSTEM]
+			  +  kcpustat.cpustat[CPUTIME_SOFTIRQ]
+			  +  kcpustat.cpustat[CPUTIME_IRQ];
+		cpus++;
+	}
+
+	/* We come here every 100ms in the worst case, so that's 100M ns of
+	 * cumulated time. By dividing by 2^16, we get the time resolution
+	 * down to 16us, ensuring we won't overflow 32-bit computations below
+	 * even up to 3k CPUs, while keeping divides cheap on smaller systems.
+	 */
+	curr_boot = ktime_get_boottime_ns() * cpus;
+	diff_boot = (curr_boot - activity_data->last_boot) >> 16;
+	diff_used = (curr_used - activity_data->last_used) >> 16;
+	activity_data->last_boot = curr_boot;
+	activity_data->last_used = curr_used;
+
+	if (diff_boot <= 0 || diff_used < 0)
+		usage = 0;
+	else if (diff_used >= diff_boot)
+		usage = 100;
+	else
+		usage = 100 * diff_used / diff_boot;
+
+	/*
+	 * Now we know the total boot_time multiplied by the number of CPUs, and
+	 * the total idle+wait time for all CPUs. We'll compare how they evolved
+	 * since last call. The % of overall CPU usage is :
+	 *
+	 *      1 - delta_idle / delta_boot
+	 *
+	 * What we want is that when the CPU usage is zero, the LED must blink
+	 * slowly with very faint flashes that are detectable but not disturbing
+	 * (typically 10ms every second, or 10ms ON, 990ms OFF). Then we want
+	 * blinking frequency to increase up to the point where the load is
+	 * enough to saturate one core in multi-core systems or 50% in single
+	 * core systems. At this point it should reach 10 Hz with a 10/90 duty
+	 * cycle (10ms ON, 90ms OFF). After this point, the blinking frequency
+	 * remains stable (10 Hz) and only the duty cycle increases to report
+	 * the activity, up to the point where we have 90ms ON, 10ms OFF when
+	 * all cores are saturated. It's important that the LED never stays in
+	 * a steady state so that it's easy to distinguish an idle or saturated
+	 * machine from a hung one.
+	 *
+	 * This gives us :
+	 *   - a target CPU usage of min(50%, 100%/#CPU) for a 10% duty cycle
+	 *     (10ms ON, 90ms OFF)
+	 *   - below target :
+	 *      ON_ms  = 10
+	 *      OFF_ms = 90 + (1 - usage/target) * 900
+	 *   - above target :
+	 *      ON_ms  = 10 + (usage-target)/(100%-target) * 80
+	 *      OFF_ms = 90 - (usage-target)/(100%-target) * 80
+	 *
+	 * In order to keep a good responsiveness, we cap the sleep time to
+	 * 100 ms and keep track of the sleep time left. This allows us to
+	 * quickly change it if needed.
+	 */
+
+	activity_data->time_left -= 100;
+	if (activity_data->time_left <= 0) {
+		activity_data->time_left = 0;
+		activity_data->state = !activity_data->state;
+		led_set_brightness_nosleep(led_cdev,
+			(activity_data->state ^ activity_data->invert) ?
+			led_cdev->blink_brightness : LED_OFF);
+	}
+
+	target = (cpus > 1) ? (100 / cpus) : 50;
+
+	if (usage < target)
+		delay = activity_data->state ?
+			10 :                        /* ON  */
+			990 - 900 * usage / target; /* OFF */
+	else
+		delay = activity_data->state ?
+			10 + 80 * (usage - target) / (100 - target) : /* ON  */
+			90 - 80 * (usage - target) / (100 - target);  /* OFF */
+
+
+	if (!activity_data->time_left || delay <= activity_data->time_left)
+		activity_data->time_left = delay;
+
+	delay = min_t(int, activity_data->time_left, 100);
+	mod_timer(&activity_data->timer, jiffies + msecs_to_jiffies(delay));
+}
+
+static ssize_t led_invert_show(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+	struct activity_data *activity_data = led_trigger_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", activity_data->invert);
+}
+
+static ssize_t led_invert_store(struct device *dev,
+                                struct device_attribute *attr,
+                                const char *buf, size_t size)
+{
+	struct activity_data *activity_data = led_trigger_get_drvdata(dev);
+	unsigned long state;
+	int ret;
+
+	ret = kstrtoul(buf, 0, &state);
+	if (ret)
+		return ret;
+
+	activity_data->invert = !!state;
+
+	return size;
+}
+
+static DEVICE_ATTR(invert, 0644, led_invert_show, led_invert_store);
+
+static struct attribute *activity_led_attrs[] = {
+	&dev_attr_invert.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(activity_led);
+
+static int activity_activate(struct led_classdev *led_cdev)
+{
+	struct activity_data *activity_data;
+
+	activity_data = kzalloc_obj(*activity_data);
+	if (!activity_data)
+		return -ENOMEM;
+
+	led_set_trigger_data(led_cdev, activity_data);
+
+	activity_data->led_cdev = led_cdev;
+	timer_setup(&activity_data->timer, led_activity_function, 0);
+	if (!led_cdev->blink_brightness)
+		led_cdev->blink_brightness = led_cdev->max_brightness;
+	led_activity_function(&activity_data->timer);
+	set_bit(LED_BLINK_SW, &led_cdev->work_flags);
+
+	return 0;
+}
+
+static void activity_deactivate(struct led_classdev *led_cdev)
+{
+	struct activity_data *activity_data = led_get_trigger_data(led_cdev);
+
+	timer_shutdown_sync(&activity_data->timer);
+	kfree(activity_data);
+	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
+}
+
+static struct led_trigger activity_led_trigger = {
+	.name       = "activity",
+	.activate   = activity_activate,
+	.deactivate = activity_deactivate,
+	.groups     = activity_led_groups,
+};
+
+static int activity_reboot_notifier(struct notifier_block *nb,
+                                    unsigned long code, void *unused)
+{
+	led_trigger_unregister(&activity_led_trigger);
+	return NOTIFY_DONE;
+}
+
+static int activity_panic_notifier(struct notifier_block *nb,
+                                   unsigned long code, void *unused)
+{
+	panic_detected = 1;
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block activity_reboot_nb = {
+	.notifier_call = activity_reboot_notifier,
+};
+
+static struct notifier_block activity_panic_nb = {
+	.notifier_call = activity_panic_notifier,
+};
+
+static int __init activity_init(void)
+{
+	int rc = led_trigger_register(&activity_led_trigger);
+
+	if (!rc) {
+		atomic_notifier_chain_register(&panic_notifier_list,
+					       &activity_panic_nb);
+		register_reboot_notifier(&activity_reboot_nb);
+	}
+	return rc;
+}
+
+static void __exit activity_exit(void)
+{
+	unregister_reboot_notifier(&activity_reboot_nb);
+	atomic_notifier_chain_unregister(&panic_notifier_list,
+					 &activity_panic_nb);
+	led_trigger_unregister(&activity_led_trigger);
+}
+
+module_init(activity_init);
+module_exit(activity_exit);
+
+MODULE_AUTHOR("Willy Tarreau <w@1wt.eu>");
+MODULE_DESCRIPTION("Activity LED trigger");
+MODULE_LICENSE("GPL v2");