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, 324 insertions, 0 deletions

diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
new file mode 100644
index 000000000..471784426
--- /dev/null
+++ b/include/drm/drm_fourcc.h
@@ -0,0 +1,324 @@
+/*
+ * Copyright (c) 2016 Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and its
+ * documentation for any purpose is hereby granted without fee, provided that
+ * the above copyright notice appear in all copies and that both that copyright
+ * notice and this permission notice appear in supporting documentation, and
+ * that the name of the copyright holders not be used in advertising or
+ * publicity pertaining to distribution of the software without specific,
+ * written prior permission.  The copyright holders make no representations
+ * about the suitability of this software for any purpose.  It is provided "as
+ * is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+ * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+ * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+ * OF THIS SOFTWARE.
+ */
+#ifndef __DRM_FOURCC_H__
+#define __DRM_FOURCC_H__
+
+#include <linux/math.h>
+#include <linux/types.h>
+#include <uapi/drm/drm_fourcc.h>
+
+/**
+ * DRM_FORMAT_MAX_PLANES - maximum number of planes a DRM format can have
+ */
+#define DRM_FORMAT_MAX_PLANES	4u
+
+/*
+ * DRM formats are little endian.  Define host endian variants for the
+ * most common formats here, to reduce the #ifdefs needed in drivers.
+ *
+ * Note that the DRM_FORMAT_BIG_ENDIAN flag should only be used in
+ * case the format can't be specified otherwise, so we don't end up
+ * with two values describing the same format.
+ */
+#ifdef __BIG_ENDIAN
+# define DRM_FORMAT_HOST_XRGB1555     (DRM_FORMAT_XRGB1555         |	\
+				       DRM_FORMAT_BIG_ENDIAN)
+# define DRM_FORMAT_HOST_RGB565       (DRM_FORMAT_RGB565           |	\
+				       DRM_FORMAT_BIG_ENDIAN)
+# define DRM_FORMAT_HOST_XRGB8888     DRM_FORMAT_BGRX8888
+# define DRM_FORMAT_HOST_ARGB8888     DRM_FORMAT_BGRA8888
+#else
+# define DRM_FORMAT_HOST_XRGB1555     DRM_FORMAT_XRGB1555
+# define DRM_FORMAT_HOST_RGB565       DRM_FORMAT_RGB565
+# define DRM_FORMAT_HOST_XRGB8888     DRM_FORMAT_XRGB8888
+# define DRM_FORMAT_HOST_ARGB8888     DRM_FORMAT_ARGB8888
+#endif
+
+struct drm_device;
+
+/**
+ * struct drm_format_info - information about a DRM format
+ */
+struct drm_format_info {
+	/** @format: 4CC format identifier (DRM_FORMAT_*) */
+	u32 format;
+
+	/**
+	 * @depth:
+	 *
+	 * Color depth (number of bits per pixel excluding padding bits),
+	 * valid for a subset of RGB formats only. This is a legacy field, do
+	 * not use in new code and set to 0 for new formats.
+	 */
+	u8 depth;
+
+	/** @num_planes: Number of color planes (1 to 3) */
+	u8 num_planes;
+
+	union {
+		/**
+		 * @cpp:
+		 *
+		 * Number of bytes per pixel (per plane), this is aliased with
+		 * @char_per_block. It is deprecated in favour of using the
+		 * triplet @char_per_block, @block_w, @block_h for better
+		 * describing the pixel format.
+		 */
+		u8 cpp[DRM_FORMAT_MAX_PLANES];
+
+		/**
+		 * @char_per_block:
+		 *
+		 * Number of bytes per block (per plane), where blocks are
+		 * defined as a rectangle of pixels which are stored next to
+		 * each other in a byte aligned memory region. Together with
+		 * @block_w and @block_h this is used to properly describe tiles
+		 * in tiled formats or to describe groups of pixels in packed
+		 * formats for which the memory needed for a single pixel is not
+		 * byte aligned.
+		 *
+		 * @cpp has been kept for historical reasons because there are
+		 * a lot of places in drivers where it's used. In drm core for
+		 * generic code paths the preferred way is to use
+		 * @char_per_block, drm_format_info_block_width() and
+		 * drm_format_info_block_height() which allows handling both
+		 * block and non-block formats in the same way.
+		 *
+		 * For formats that are intended to be used only with non-linear
+		 * modifiers both @cpp and @char_per_block must be 0 in the
+		 * generic format table. Drivers could supply accurate
+		 * information from their drm_mode_config.get_format_info hook
+		 * if they want the core to be validating the pitch.
+		 */
+		u8 char_per_block[DRM_FORMAT_MAX_PLANES];
+	};
+
+	/**
+	 * @block_w:
+	 *
+	 * Block width in pixels, this is intended to be accessed through
+	 * drm_format_info_block_width()
+	 */
+	u8 block_w[DRM_FORMAT_MAX_PLANES];
+
+	/**
+	 * @block_h:
+	 *
+	 * Block height in pixels, this is intended to be accessed through
+	 * drm_format_info_block_height()
+	 */
+	u8 block_h[DRM_FORMAT_MAX_PLANES];
+
+	/** @hsub: Horizontal chroma subsampling factor */
+	u8 hsub;
+	/** @vsub: Vertical chroma subsampling factor */
+	u8 vsub;
+
+	/** @has_alpha: Does the format embeds an alpha component? */
+	bool has_alpha;
+
+	/** @is_yuv: Is it a YUV format? */
+	bool is_yuv;
+
+	/** @is_color_indexed: Is it a color-indexed format? */
+	bool is_color_indexed;
+};
+
+/**
+ * drm_format_info_is_yuv_packed - check that the format info matches a YUV
+ * format with data laid in a single plane
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a packed YUV format.
+ */
+static inline bool
+drm_format_info_is_yuv_packed(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->num_planes == 1;
+}
+
+/**
+ * drm_format_info_is_yuv_semiplanar - check that the format info matches a YUV
+ * format with data laid in two planes (luminance and chrominance)
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a semiplanar YUV format.
+ */
+static inline bool
+drm_format_info_is_yuv_semiplanar(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->num_planes == 2;
+}
+
+/**
+ * drm_format_info_is_yuv_planar - check that the format info matches a YUV
+ * format with data laid in three planes (one for each YUV component)
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a planar YUV format.
+ */
+static inline bool
+drm_format_info_is_yuv_planar(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->num_planes == 3;
+}
+
+/**
+ * drm_format_info_is_yuv_sampling_410 - check that the format info matches a
+ * YUV format with 4:1:0 sub-sampling
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a YUV format with 4:1:0
+ * sub-sampling.
+ */
+static inline bool
+drm_format_info_is_yuv_sampling_410(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->hsub == 4 && info->vsub == 4;
+}
+
+/**
+ * drm_format_info_is_yuv_sampling_411 - check that the format info matches a
+ * YUV format with 4:1:1 sub-sampling
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a YUV format with 4:1:1
+ * sub-sampling.
+ */
+static inline bool
+drm_format_info_is_yuv_sampling_411(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->hsub == 4 && info->vsub == 1;
+}
+
+/**
+ * drm_format_info_is_yuv_sampling_420 - check that the format info matches a
+ * YUV format with 4:2:0 sub-sampling
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a YUV format with 4:2:0
+ * sub-sampling.
+ */
+static inline bool
+drm_format_info_is_yuv_sampling_420(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->hsub == 2 && info->vsub == 2;
+}
+
+/**
+ * drm_format_info_is_yuv_sampling_422 - check that the format info matches a
+ * YUV format with 4:2:2 sub-sampling
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a YUV format with 4:2:2
+ * sub-sampling.
+ */
+static inline bool
+drm_format_info_is_yuv_sampling_422(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->hsub == 2 && info->vsub == 1;
+}
+
+/**
+ * drm_format_info_is_yuv_sampling_444 - check that the format info matches a
+ * YUV format with 4:4:4 sub-sampling
+ * @info: format info
+ *
+ * Returns:
+ * A boolean indicating whether the format info matches a YUV format with 4:4:4
+ * sub-sampling.
+ */
+static inline bool
+drm_format_info_is_yuv_sampling_444(const struct drm_format_info *info)
+{
+	return info->is_yuv && info->hsub == 1 && info->vsub == 1;
+}
+
+/**
+ * drm_format_info_plane_width - width of the plane given the first plane
+ * @info: pixel format info
+ * @width: width of the first plane
+ * @plane: plane index
+ *
+ * Returns:
+ * The width of @plane, given that the width of the first plane is @width.
+ */
+static inline
+int drm_format_info_plane_width(const struct drm_format_info *info, int width,
+				int plane)
+{
+	if (!info || plane >= info->num_planes)
+		return 0;
+
+	if (plane == 0)
+		return width;
+
+	return DIV_ROUND_UP(width, info->hsub);
+}
+
+/**
+ * drm_format_info_plane_height - height of the plane given the first plane
+ * @info: pixel format info
+ * @height: height of the first plane
+ * @plane: plane index
+ *
+ * Returns:
+ * The height of @plane, given that the height of the first plane is @height.
+ */
+static inline
+int drm_format_info_plane_height(const struct drm_format_info *info, int height,
+				 int plane)
+{
+	if (!info || plane >= info->num_planes)
+		return 0;
+
+	if (plane == 0)
+		return height;
+
+	return DIV_ROUND_UP(height, info->vsub);
+}
+
+const struct drm_format_info *__drm_format_info(u32 format);
+const struct drm_format_info *drm_format_info(u32 format);
+const struct drm_format_info *
+drm_get_format_info(struct drm_device *dev,
+		    u32 pixel_format, u64 modifier);
+uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth);
+uint32_t drm_driver_legacy_fb_format(struct drm_device *dev,
+				     uint32_t bpp, uint32_t depth);
+uint32_t drm_driver_color_mode_format(struct drm_device *dev, unsigned int color_mode);
+unsigned int drm_format_info_block_width(const struct drm_format_info *info,
+					 int plane);
+unsigned int drm_format_info_block_height(const struct drm_format_info *info,
+					  int plane);
+unsigned int drm_format_info_bpp(const struct drm_format_info *info, int plane);
+uint64_t drm_format_info_min_pitch(const struct drm_format_info *info,
+				   int plane, unsigned int buffer_width);
+
+#endif /* __DRM_FOURCC_H__ */