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, 131 insertions, 0 deletions

diff --git a/arch/mips/bcm63xx/dev-flash.c b/arch/mips/bcm63xx/dev-flash.c
new file mode 100644
index 000000000..f9cc015d3
--- /dev/null
+++ b/arch/mips/bcm63xx/dev-flash.c
@@ -0,0 +1,131 @@
+/*
+ * Broadcom BCM63xx flash registration
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ * Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2012 Jonas Gorski <jonas.gorski@gmail.com>
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/physmap.h>
+
+#include <bcm63xx_cpu.h>
+#include <bcm63xx_dev_flash.h>
+#include <bcm63xx_regs.h>
+#include <bcm63xx_io.h>
+
+static struct mtd_partition mtd_partitions[] = {
+	{
+		.name		= "cfe",
+		.offset		= 0x0,
+		.size		= 0x40000,
+	}
+};
+
+static const char *bcm63xx_part_types[] = { "bcm63xxpart", NULL };
+
+static struct physmap_flash_data flash_data = {
+	.width			= 2,
+	.parts			= mtd_partitions,
+	.part_probe_types	= bcm63xx_part_types,
+};
+
+static struct resource mtd_resources[] = {
+	{
+		.start		= 0,	/* filled at runtime */
+		.end		= 0,	/* filled at runtime */
+		.flags		= IORESOURCE_MEM,
+	}
+};
+
+static struct platform_device mtd_dev = {
+	.name			= "physmap-flash",
+	.resource		= mtd_resources,
+	.num_resources		= ARRAY_SIZE(mtd_resources),
+	.dev			= {
+		.platform_data	= &flash_data,
+	},
+};
+
+static int __init bcm63xx_detect_flash_type(void)
+{
+	u32 val;
+
+	switch (bcm63xx_get_cpu_id()) {
+	case BCM6328_CPU_ID:
+		val = bcm_misc_readl(MISC_STRAPBUS_6328_REG);
+		if (val & STRAPBUS_6328_BOOT_SEL_SERIAL)
+			return BCM63XX_FLASH_TYPE_SERIAL;
+		else
+			return BCM63XX_FLASH_TYPE_NAND;
+	case BCM6338_CPU_ID:
+	case BCM6345_CPU_ID:
+	case BCM6348_CPU_ID:
+		/* no way to auto detect so assume parallel */
+		return BCM63XX_FLASH_TYPE_PARALLEL;
+	case BCM3368_CPU_ID:
+	case BCM6358_CPU_ID:
+		val = bcm_gpio_readl(GPIO_STRAPBUS_REG);
+		if (val & STRAPBUS_6358_BOOT_SEL_PARALLEL)
+			return BCM63XX_FLASH_TYPE_PARALLEL;
+		else
+			return BCM63XX_FLASH_TYPE_SERIAL;
+	case BCM6362_CPU_ID:
+		val = bcm_misc_readl(MISC_STRAPBUS_6362_REG);
+		if (val & STRAPBUS_6362_BOOT_SEL_SERIAL)
+			return BCM63XX_FLASH_TYPE_SERIAL;
+		else
+			return BCM63XX_FLASH_TYPE_NAND;
+	case BCM6368_CPU_ID:
+		val = bcm_gpio_readl(GPIO_STRAPBUS_REG);
+		switch (val & STRAPBUS_6368_BOOT_SEL_MASK) {
+		case STRAPBUS_6368_BOOT_SEL_NAND:
+			return BCM63XX_FLASH_TYPE_NAND;
+		case STRAPBUS_6368_BOOT_SEL_SERIAL:
+			return BCM63XX_FLASH_TYPE_SERIAL;
+		case STRAPBUS_6368_BOOT_SEL_PARALLEL:
+			return BCM63XX_FLASH_TYPE_PARALLEL;
+		}
+		fallthrough;
+	default:
+		return -EINVAL;
+	}
+}
+
+int __init bcm63xx_flash_register(void)
+{
+	int flash_type;
+	u32 val;
+
+	flash_type = bcm63xx_detect_flash_type();
+
+	switch (flash_type) {
+	case BCM63XX_FLASH_TYPE_PARALLEL:
+		/* read base address of boot chip select (0) */
+		val = bcm_mpi_readl(MPI_CSBASE_REG(0));
+		val &= MPI_CSBASE_BASE_MASK;
+
+		mtd_resources[0].start = val;
+		mtd_resources[0].end = 0x1FFFFFFF;
+
+		return platform_device_register(&mtd_dev);
+	case BCM63XX_FLASH_TYPE_SERIAL:
+		pr_warn("unsupported serial flash detected\n");
+		return -ENODEV;
+	case BCM63XX_FLASH_TYPE_NAND:
+		pr_warn("unsupported NAND flash detected\n");
+		return -ENODEV;
+	default:
+		pr_err("flash detection failed for BCM%x: %d\n",
+		       bcm63xx_get_cpu_id(), flash_type);
+		return -ENODEV;
+	}
+}