Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEADgrafted

Changes:

Make expedited grace periods expedite normal RCU callbacks

Miscellaneous fixes:
 * Improve diagnostic output with character task states.
 * Mark accesses to inform KCSAN of concurrency design.
 * Move from kmalloc() to kmalloc_obj().
 * Documentation updates.
 * Improve handling of RCU deferred quiescent states.
 * Clean up unused function arguments and structure fields.
 * Reduce show_rcu_gp_kthreads() stack space.

Tasks RCU updates:
 * Clean up after SRCU re-implementation of Tasks Trace RCU.
 * Mark accesses to inform KCSAN of concurrency design.
 * Add ->lazy_timer status to diagnostic output.
 * Remove an unnecessary memory barrier.
 * Fix a data race, courtesy of KCSAN.
 * Documentation updates.
 * Convert cond_resched_tasks_rcu_qs() from macro to static inline
   function.

SRCU updates:
 * Add Rust helpers for SRCU.
 * Avoid losing queued work at cleanup_srcu_struct() time.

Torture-test updates:
 * Preparation work for immediate RCU priority deboosting.
 * Test RCU readers from real interrupt handlers (as opposed to softirq).
 * Simplify code through use of cpumask_next_wrap().
 * Improve diagnostic output with character task states.
 * Add rcutorture.nwriters parameter to allow lightweight stall testing,
   and rcutorture.stall_only to make doing so easier.
 * Test an RCU Tasks Trace grace period implying an RCU grace period.
 * Make RCU Tasks Trace torturing track reader batches.
 * Fix a data race, courtesy of KCSAN.
 * Plug a shuffle_tmp_mask memory leak on kthread spawn failure.

1 files changed, 161 insertions, 0 deletions

diff --git a/drivers/soc/tegra/common.c b/drivers/soc/tegra/common.c
new file mode 100644
index 000000000..0864eb018
--- /dev/null
+++ b/drivers/soc/tegra/common.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2014 NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#define dev_fmt(fmt)	"tegra-soc: " fmt
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/of.h>
+#include <linux/pm_opp.h>
+#include <linux/pm_runtime.h>
+
+#include <soc/tegra/common.h>
+#include <soc/tegra/fuse.h>
+
+static const struct of_device_id tegra_machine_match[] = {
+	{ .compatible = "nvidia,tegra20", },
+	{ .compatible = "nvidia,tegra30", },
+	{ .compatible = "nvidia,tegra114", },
+	{ .compatible = "nvidia,tegra124", },
+	{ .compatible = "nvidia,tegra132", },
+	{ .compatible = "nvidia,tegra210", },
+	{ }
+};
+
+bool soc_is_tegra(void)
+{
+	return of_machine_device_match(tegra_machine_match);
+}
+
+static int tegra_core_dev_init_opp_state(struct device *dev)
+{
+	unsigned long rate;
+	struct clk *clk;
+	bool rpm_enabled;
+	int err;
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "failed to get clk: %pe\n", clk);
+		return PTR_ERR(clk);
+	}
+
+	rate = clk_get_rate(clk);
+	if (!rate) {
+		dev_err(dev, "failed to get clk rate\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Runtime PM of the device must be enabled in order to set up
+	 * GENPD's performance properly because GENPD core checks whether
+	 * device is suspended and this check doesn't work while RPM is
+	 * disabled. This makes sure the OPP vote below gets cached in
+	 * GENPD for the device. Instead, the vote is done the next time
+	 * the device gets runtime resumed.
+	 */
+	rpm_enabled = pm_runtime_enabled(dev);
+	if (!rpm_enabled)
+		pm_runtime_enable(dev);
+
+	/* should never happen in practice */
+	if (!pm_runtime_enabled(dev)) {
+		dev_WARN(dev, "failed to enable runtime PM\n");
+		pm_runtime_disable(dev);
+		return -EINVAL;
+	}
+
+	/* first dummy rate-setting initializes voltage vote */
+	err = dev_pm_opp_set_rate(dev, rate);
+
+	if (!rpm_enabled)
+		pm_runtime_disable(dev);
+
+	if (err) {
+		dev_err(dev, "failed to initialize OPP clock: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+/**
+ * devm_tegra_core_dev_init_opp_table() - initialize OPP table
+ * @dev: device for which OPP table is initialized
+ * @params: pointer to the OPP table configuration
+ *
+ * This function will initialize OPP table and sync OPP state of a Tegra SoC
+ * core device.
+ *
+ * Return: 0 on success or errorno.
+ */
+int devm_tegra_core_dev_init_opp_table(struct device *dev,
+				       struct tegra_core_opp_params *params)
+{
+	u32 hw_version;
+	int err;
+	/*
+	 * The clk's connection id to set is NULL and this is a NULL terminated
+	 * array, hence two NULL entries.
+	 */
+	const char *clk_names[] = { NULL, NULL };
+	struct dev_pm_opp_config config = {
+		/*
+		 * For some devices we don't have any OPP table in the DT, and
+		 * in order to use the same code path for all the devices, we
+		 * create a dummy OPP table for them via this. The dummy OPP
+		 * table is only capable of doing clk_set_rate() on invocation
+		 * of dev_pm_opp_set_rate() and doesn't provide any other
+		 * functionality.
+		 */
+		.clk_names = clk_names,
+	};
+
+	if (of_machine_is_compatible("nvidia,tegra20")) {
+		hw_version = BIT(tegra_sku_info.soc_process_id);
+		config.supported_hw = &hw_version;
+		config.supported_hw_count = 1;
+	} else if (of_machine_is_compatible("nvidia,tegra30") ||
+		   of_machine_is_compatible("nvidia,tegra114")) {
+		hw_version = BIT(tegra_sku_info.soc_speedo_id);
+		config.supported_hw = &hw_version;
+		config.supported_hw_count = 1;
+	}
+
+	err = devm_pm_opp_set_config(dev, &config);
+	if (err) {
+		dev_err(dev, "failed to set OPP config: %d\n", err);
+		return err;
+	}
+
+	/*
+	 * Tegra124+ doesn't support OPP yet, return early for pre-Tegra124
+	 * case.
+	 */
+	if (!config.supported_hw)
+		return -ENODEV;
+
+	/*
+	 * Older device-trees have an empty OPP table, we will get
+	 * -ENODEV from devm_pm_opp_of_add_table() in this case.
+	 */
+	err = devm_pm_opp_of_add_table(dev);
+	if (err) {
+		if (err != -ENODEV)
+			dev_err(dev, "failed to add OPP table: %d\n", err);
+
+		return err;
+	}
+
+	if (params->init_state) {
+		err = tegra_core_dev_init_opp_state(dev);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_tegra_core_dev_init_opp_table);