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, 63 insertions, 0 deletions

diff --git a/drivers/video/fbdev/sbuslib.h b/drivers/video/fbdev/sbuslib.h
new file mode 100644
index 000000000..e9af2dc93
--- /dev/null
+++ b/drivers/video/fbdev/sbuslib.h
@@ -0,0 +1,63 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* sbuslib.h: SBUS fb helper library interfaces */
+#ifndef _SBUSLIB_H
+#define _SBUSLIB_H
+
+struct device_node;
+struct fb_info;
+struct fb_var_screeninfo;
+struct vm_area_struct;
+
+struct sbus_mmap_map {
+	unsigned long voff;
+	unsigned long poff;
+	unsigned long size;
+};
+
+#define SBUS_MMAP_FBSIZE(n) (-n)
+#define SBUS_MMAP_EMPTY	0x80000000
+
+extern void sbusfb_fill_var(struct fb_var_screeninfo *var,
+			    struct device_node *dp, int bpp);
+extern int sbusfb_mmap_helper(const struct sbus_mmap_map *map,
+			      unsigned long physbase, unsigned long fbsize,
+			      unsigned long iospace,
+			      struct vm_area_struct *vma);
+int sbusfb_ioctl_helper(unsigned long cmd, unsigned long arg,
+			struct fb_info *info,
+			int type, int fb_depth, unsigned long fb_size);
+int sbusfb_compat_ioctl(struct fb_info *info, unsigned int cmd,
+			unsigned long arg);
+
+/*
+ * Initialize struct fb_ops for SBUS I/O.
+ */
+
+#define __FB_DEFAULT_SBUS_OPS_RDWR(__prefix) \
+	.fb_read	= fb_io_read, \
+	.fb_write	= fb_io_write
+
+#define __FB_DEFAULT_SBUS_OPS_DRAW(__prefix) \
+	.fb_fillrect	= cfb_fillrect, \
+	.fb_copyarea	= cfb_copyarea, \
+	.fb_imageblit	= cfb_imageblit
+
+#ifdef CONFIG_COMPAT
+#define __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix) \
+	.fb_ioctl		= __prefix ## _sbusfb_ioctl, \
+	.fb_compat_ioctl	= sbusfb_compat_ioctl
+#else
+#define __FB_DEFAULT_SBUS_OPS_IOCTL(__prefix) \
+	.fb_ioctl	= __prefix ## _sbusfb_ioctl
+#endif
+
+#define __FB_DEFAULT_SBUS_OPS_MMAP(__prefix) \
+	.fb_mmap	= __prefix ## _sbusfb_mmap
+
+#define FB_DEFAULT_SBUS_OPS(__prefix) \
+	__FB_DEFAULT_SBUS_OPS_RDWR(__prefix), \
+	__FB_DEFAULT_SBUS_OPS_DRAW(__prefix), \
+	__FB_DEFAULT_SBUS_OPS_IOCTL(__prefix), \
+	__FB_DEFAULT_SBUS_OPS_MMAP(__prefix)
+
+#endif /* _SBUSLIB_H */