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.

2 files changed, 241 insertions, 0 deletions

diff --git a/drivers/clk/axis/Makefile b/drivers/clk/axis/Makefile
new file mode 100644
index 000000000..a6a9bbe7f
--- /dev/null
+++ b/drivers/clk/axis/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_MACH_ARTPEC6)	+= clk-artpec6.o
diff --git a/drivers/clk/axis/clk-artpec6.c b/drivers/clk/axis/clk-artpec6.c
new file mode 100644
index 000000000..a6f149962
--- /dev/null
+++ b/drivers/clk/axis/clk-artpec6.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ARTPEC-6 clock initialization
+ *
+ * Copyright 2015-2016 Axis Communications AB.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <dt-bindings/clock/axis,artpec6-clkctrl.h>
+
+#define NUM_I2S_CLOCKS 2
+
+struct artpec6_clkctrl_drvdata {
+	struct clk *clk_table[ARTPEC6_CLK_NUMCLOCKS];
+	void __iomem *syscon_base;
+	struct clk_onecell_data clk_data;
+	spinlock_t i2scfg_lock;
+};
+
+static struct artpec6_clkctrl_drvdata *clkdata;
+
+static const char *const i2s_clk_names[NUM_I2S_CLOCKS] = {
+	"i2s0",
+	"i2s1",
+};
+
+static const int i2s_clk_indexes[NUM_I2S_CLOCKS] = {
+	ARTPEC6_CLK_I2S0_CLK,
+	ARTPEC6_CLK_I2S1_CLK,
+};
+
+static void of_artpec6_clkctrl_setup(struct device_node *np)
+{
+	int i;
+	const char *sys_refclk_name;
+	u32 pll_mode, pll_m, pll_n;
+	struct clk **clks;
+
+	/* Mandatory parent clock. */
+	i = of_property_match_string(np, "clock-names", "sys_refclk");
+	if (i < 0)
+		return;
+
+	sys_refclk_name = of_clk_get_parent_name(np, i);
+
+	clkdata = kzalloc_obj(*clkdata);
+	if (!clkdata)
+		return;
+
+	clks = clkdata->clk_table;
+
+	for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i)
+		clks[i] = ERR_PTR(-EPROBE_DEFER);
+
+	clkdata->syscon_base = of_iomap(np, 0);
+	BUG_ON(clkdata->syscon_base == NULL);
+
+	/* Read PLL1 factors configured by boot strap pins. */
+	pll_mode = (readl(clkdata->syscon_base) >> 6) & 3;
+	switch (pll_mode) {
+	case 0:		/* DDR3-2133 mode */
+		pll_m = 4;
+		pll_n = 85;
+		break;
+	case 1:		/* DDR3-1866 mode */
+		pll_m = 6;
+		pll_n = 112;
+		break;
+	case 2:		/* DDR3-1600 mode */
+		pll_m = 4;
+		pll_n = 64;
+		break;
+	case 3:		/* DDR3-1333 mode */
+		pll_m = 8;
+		pll_n = 106;
+		break;
+	}
+
+	clks[ARTPEC6_CLK_CPU] =
+	    clk_register_fixed_factor(NULL, "cpu", sys_refclk_name, 0, pll_n,
+				      pll_m);
+	clks[ARTPEC6_CLK_CPU_PERIPH] =
+	    clk_register_fixed_factor(NULL, "cpu_periph", "cpu", 0, 1, 2);
+
+	/* EPROBE_DEFER on the apb_clock is not handled in amba devices. */
+	clks[ARTPEC6_CLK_UART_PCLK] =
+	    clk_register_fixed_factor(NULL, "uart_pclk", "cpu", 0, 1, 8);
+	clks[ARTPEC6_CLK_UART_REFCLK] =
+	    clk_register_fixed_rate(NULL, "uart_ref", sys_refclk_name, 0,
+				    50000000);
+
+	clks[ARTPEC6_CLK_SPI_PCLK] =
+	    clk_register_fixed_factor(NULL, "spi_pclk", "cpu", 0, 1, 8);
+	clks[ARTPEC6_CLK_SPI_SSPCLK] =
+	    clk_register_fixed_rate(NULL, "spi_sspclk", sys_refclk_name, 0,
+				    50000000);
+
+	clks[ARTPEC6_CLK_DBG_PCLK] =
+	    clk_register_fixed_factor(NULL, "dbg_pclk", "cpu", 0, 1, 8);
+
+	clkdata->clk_data.clks = clkdata->clk_table;
+	clkdata->clk_data.clk_num = ARTPEC6_CLK_NUMCLOCKS;
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, &clkdata->clk_data);
+}
+
+CLK_OF_DECLARE_DRIVER(artpec6_clkctrl, "axis,artpec6-clkctrl",
+		      of_artpec6_clkctrl_setup);
+
+static int artpec6_clkctrl_probe(struct platform_device *pdev)
+{
+	int propidx;
+	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct clk **clks = clkdata->clk_table;
+	const char *sys_refclk_name;
+	const char *i2s_refclk_name = NULL;
+	const char *frac_clk_name[2] = { NULL, NULL };
+	const char *i2s_mux_parents[2];
+	u32 muxreg;
+	int i;
+	int err = 0;
+
+	/* Mandatory parent clock. */
+	propidx = of_property_match_string(np, "clock-names", "sys_refclk");
+	if (propidx < 0)
+		return -EINVAL;
+
+	sys_refclk_name = of_clk_get_parent_name(np, propidx);
+
+	/* Find clock names of optional parent clocks. */
+	propidx = of_property_match_string(np, "clock-names", "i2s_refclk");
+	if (propidx >= 0)
+		i2s_refclk_name = of_clk_get_parent_name(np, propidx);
+
+	propidx = of_property_match_string(np, "clock-names", "frac_clk0");
+	if (propidx >= 0)
+		frac_clk_name[0] = of_clk_get_parent_name(np, propidx);
+	propidx = of_property_match_string(np, "clock-names", "frac_clk1");
+	if (propidx >= 0)
+		frac_clk_name[1] = of_clk_get_parent_name(np, propidx);
+
+	spin_lock_init(&clkdata->i2scfg_lock);
+
+	clks[ARTPEC6_CLK_NAND_CLKA] =
+	    clk_register_fixed_factor(dev, "nand_clka", "cpu", 0, 1, 8);
+	clks[ARTPEC6_CLK_NAND_CLKB] =
+	    clk_register_fixed_rate(dev, "nand_clkb", sys_refclk_name, 0,
+				    100000000);
+	clks[ARTPEC6_CLK_ETH_ACLK] =
+	    clk_register_fixed_factor(dev, "eth_aclk", "cpu", 0, 1, 4);
+	clks[ARTPEC6_CLK_DMA_ACLK] =
+	    clk_register_fixed_factor(dev, "dma_aclk", "cpu", 0, 1, 4);
+	clks[ARTPEC6_CLK_PTP_REF] =
+	    clk_register_fixed_rate(dev, "ptp_ref", sys_refclk_name, 0,
+				    100000000);
+	clks[ARTPEC6_CLK_SD_PCLK] =
+	    clk_register_fixed_rate(dev, "sd_pclk", sys_refclk_name, 0,
+				    100000000);
+	clks[ARTPEC6_CLK_SD_IMCLK] =
+	    clk_register_fixed_rate(dev, "sd_imclk", sys_refclk_name, 0,
+				    100000000);
+	clks[ARTPEC6_CLK_I2S_HST] =
+	    clk_register_fixed_factor(dev, "i2s_hst", "cpu", 0, 1, 8);
+
+	for (i = 0; i < NUM_I2S_CLOCKS; ++i) {
+		if (i2s_refclk_name && frac_clk_name[i]) {
+			i2s_mux_parents[0] = frac_clk_name[i];
+			i2s_mux_parents[1] = i2s_refclk_name;
+
+			clks[i2s_clk_indexes[i]] =
+			    clk_register_mux(dev, i2s_clk_names[i],
+					     i2s_mux_parents, 2,
+					     CLK_SET_RATE_NO_REPARENT |
+					     CLK_SET_RATE_PARENT,
+					     clkdata->syscon_base + 0x14, i, 1,
+					     0, &clkdata->i2scfg_lock);
+		} else if (frac_clk_name[i]) {
+			/* Lock the mux for internal clock reference. */
+			muxreg = readl(clkdata->syscon_base + 0x14);
+			muxreg &= ~BIT(i);
+			writel(muxreg, clkdata->syscon_base + 0x14);
+			clks[i2s_clk_indexes[i]] =
+			    clk_register_fixed_factor(dev, i2s_clk_names[i],
+						      frac_clk_name[i], 0, 1,
+						      1);
+		} else if (i2s_refclk_name) {
+			/* Lock the mux for external clock reference. */
+			muxreg = readl(clkdata->syscon_base + 0x14);
+			muxreg |= BIT(i);
+			writel(muxreg, clkdata->syscon_base + 0x14);
+			clks[i2s_clk_indexes[i]] =
+			    clk_register_fixed_factor(dev, i2s_clk_names[i],
+						      i2s_refclk_name, 0, 1, 1);
+		}
+	}
+
+	clks[ARTPEC6_CLK_I2C] =
+	    clk_register_fixed_rate(dev, "i2c", sys_refclk_name, 0, 100000000);
+
+	clks[ARTPEC6_CLK_SYS_TIMER] =
+	    clk_register_fixed_rate(dev, "timer", sys_refclk_name, 0,
+				    100000000);
+	clks[ARTPEC6_CLK_FRACDIV_IN] =
+	    clk_register_fixed_rate(dev, "fracdiv_in", sys_refclk_name, 0,
+				    600000000);
+
+	for (i = 0; i < ARTPEC6_CLK_NUMCLOCKS; ++i) {
+		if (IS_ERR(clks[i]) && PTR_ERR(clks[i]) != -EPROBE_DEFER) {
+			dev_err(dev,
+				"Failed to register clock at index %d err=%ld\n",
+				i, PTR_ERR(clks[i]));
+			err = PTR_ERR(clks[i]);
+		}
+	}
+
+	return err;
+}
+
+static const struct of_device_id artpec_clkctrl_of_match[] = {
+	{ .compatible = "axis,artpec6-clkctrl" },
+	{}
+};
+
+static struct platform_driver artpec6_clkctrl_driver = {
+	.probe = artpec6_clkctrl_probe,
+	.driver = {
+		   .name = "artpec6_clkctrl",
+		   .of_match_table = artpec_clkctrl_of_match,
+	},
+};
+
+builtin_platform_driver(artpec6_clkctrl_driver);