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, 80 insertions, 0 deletions

diff --git a/include/uapi/misc/ocxl.h b/include/uapi/misc/ocxl.h
new file mode 100644
index 000000000..6d29a60a8
--- /dev/null
+++ b/include/uapi/misc/ocxl.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/* Copyright 2017 IBM Corp. */
+#ifndef _UAPI_MISC_OCXL_H
+#define _UAPI_MISC_OCXL_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+enum ocxl_event_type {
+	OCXL_AFU_EVENT_XSL_FAULT_ERROR = 0,
+};
+
+#define OCXL_KERNEL_EVENT_FLAG_LAST 0x0001  /* This is the last event pending */
+
+struct ocxl_kernel_event_header {
+	__u16 type;
+	__u16 flags;
+	__u32 reserved;
+};
+
+struct ocxl_kernel_event_xsl_fault_error {
+	__u64 addr;
+	__u64 dsisr;
+	__u64 count;
+	__u64 reserved;
+};
+
+struct ocxl_ioctl_attach {
+	__u64 amr;
+	__u64 reserved1;
+	__u64 reserved2;
+	__u64 reserved3;
+};
+
+struct ocxl_ioctl_metadata {
+	__u16 version; /* struct version, always backwards compatible */
+
+	/* Version 0 fields */
+	__u8  afu_version_major;
+	__u8  afu_version_minor;
+	__u32 pasid;		/* PASID assigned to the current context */
+
+	__u64 pp_mmio_size;	/* Per PASID MMIO size */
+	__u64 global_mmio_size;
+
+	/* End version 0 fields */
+
+	__u64 reserved[13]; /* Total of 16*u64 */
+};
+
+struct ocxl_ioctl_p9_wait {
+	__u16 thread_id; /* The thread ID required to wake this thread */
+	__u16 reserved1;
+	__u32 reserved2;
+	__u64 reserved3[3];
+};
+
+#define OCXL_IOCTL_FEATURES_FLAGS0_P9_WAIT	0x01
+struct ocxl_ioctl_features {
+	__u64 flags[4];
+};
+
+struct ocxl_ioctl_irq_fd {
+	__u64 irq_offset;
+	__s32 eventfd;
+	__u32 reserved;
+};
+
+/* ioctl numbers */
+#define OCXL_MAGIC 0xCA
+/* AFU devices */
+#define OCXL_IOCTL_ATTACH	_IOW(OCXL_MAGIC, 0x10, struct ocxl_ioctl_attach)
+#define OCXL_IOCTL_IRQ_ALLOC	_IOR(OCXL_MAGIC, 0x11, __u64)
+#define OCXL_IOCTL_IRQ_FREE	_IOW(OCXL_MAGIC, 0x12, __u64)
+#define OCXL_IOCTL_IRQ_SET_FD	_IOW(OCXL_MAGIC, 0x13, struct ocxl_ioctl_irq_fd)
+#define OCXL_IOCTL_GET_METADATA _IOR(OCXL_MAGIC, 0x14, struct ocxl_ioctl_metadata)
+#define OCXL_IOCTL_ENABLE_P9_WAIT	_IOR(OCXL_MAGIC, 0x15, struct ocxl_ioctl_p9_wait)
+#define OCXL_IOCTL_GET_FEATURES _IOR(OCXL_MAGIC, 0x16, struct ocxl_ioctl_features)
+
+#endif /* _UAPI_MISC_OCXL_H */