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, 205 insertions, 0 deletions

diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
new file mode 100644
index 000000000..571e6ca11
--- /dev/null
+++ b/drivers/input/mouse/elantech.h
@@ -0,0 +1,205 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Elantech Touchpad driver (v6)
+ *
+ * Copyright (C) 2007-2009 Arjan Opmeer <arjan@opmeer.net>
+ *
+ * Trademarks are the property of their respective owners.
+ */
+
+#ifndef _ELANTECH_H
+#define _ELANTECH_H
+
+/*
+ * Command values for Synaptics style queries
+ */
+#define ETP_FW_ID_QUERY			0x00
+#define ETP_FW_VERSION_QUERY		0x01
+#define ETP_CAPABILITIES_QUERY		0x02
+#define ETP_SAMPLE_QUERY		0x03
+#define ETP_RESOLUTION_QUERY		0x04
+#define ETP_ICBODY_QUERY		0x05
+
+/*
+ * Command values for register reading or writing
+ */
+#define ETP_REGISTER_READ		0x10
+#define ETP_REGISTER_WRITE		0x11
+#define ETP_REGISTER_READWRITE		0x00
+
+/*
+ * Hardware version 2 custom PS/2 command value
+ */
+#define ETP_PS2_CUSTOM_COMMAND		0xf8
+
+/*
+ * Times to retry a ps2_command and millisecond delay between tries
+ */
+#define ETP_PS2_COMMAND_TRIES		3
+#define ETP_PS2_COMMAND_DELAY		500
+
+/*
+ * Times to try to read back a register and millisecond delay between tries
+ */
+#define ETP_READ_BACK_TRIES		5
+#define ETP_READ_BACK_DELAY		2000
+
+/*
+ * Register bitmasks for hardware version 1
+ */
+#define ETP_R10_ABSOLUTE_MODE		0x04
+#define ETP_R11_4_BYTE_MODE		0x02
+
+/*
+ * Capability bitmasks
+ */
+#define ETP_CAP_HAS_ROCKER		0x04
+
+/*
+ * One hard to find application note states that X axis range is 0 to 576
+ * and Y axis range is 0 to 384 for harware version 1.
+ * Edge fuzz might be necessary because of bezel around the touchpad
+ */
+#define ETP_EDGE_FUZZ_V1		32
+
+#define ETP_XMIN_V1			(  0 + ETP_EDGE_FUZZ_V1)
+#define ETP_XMAX_V1			(576 - ETP_EDGE_FUZZ_V1)
+#define ETP_YMIN_V1			(  0 + ETP_EDGE_FUZZ_V1)
+#define ETP_YMAX_V1			(384 - ETP_EDGE_FUZZ_V1)
+
+/*
+ * The resolution for older v2 hardware doubled.
+ * (newer v2's firmware provides command so we can query)
+ */
+#define ETP_XMIN_V2			0
+#define ETP_XMAX_V2			1152
+#define ETP_YMIN_V2			0
+#define ETP_YMAX_V2			768
+
+#define ETP_PMIN_V2			0
+#define ETP_PMAX_V2			255
+#define ETP_WMIN_V2			0
+#define ETP_WMAX_V2			15
+
+/*
+ * v3 hardware has 2 kinds of packet types,
+ * v4 hardware has 3.
+ */
+#define PACKET_UNKNOWN			0x01
+#define PACKET_DEBOUNCE			0x02
+#define PACKET_V3_HEAD			0x03
+#define PACKET_V3_TAIL			0x04
+#define PACKET_V4_HEAD			0x05
+#define PACKET_V4_MOTION		0x06
+#define PACKET_V4_STATUS		0x07
+#define PACKET_TRACKPOINT		0x08
+
+/*
+ * track up to 5 fingers for v4 hardware
+ */
+#define ETP_MAX_FINGERS			5
+
+/*
+ * weight value for v4 hardware
+ */
+#define ETP_WEIGHT_VALUE		5
+
+/*
+ * Bus information on 3rd byte of query ETP_RESOLUTION_QUERY(0x04)
+ */
+#define ETP_BUS_PS2_ONLY		0
+#define ETP_BUS_SMB_ALERT_ONLY		1
+#define ETP_BUS_SMB_HST_NTFY_ONLY	2
+#define ETP_BUS_PS2_SMB_ALERT		3
+#define ETP_BUS_PS2_SMB_HST_NTFY	4
+
+/*
+ * New ICs are either using SMBus Host Notify or just plain PS2.
+ *
+ * ETP_FW_VERSION_QUERY is:
+ * Byte 1:
+ *  - bit 0..3: IC BODY
+ * Byte 2:
+ *  - bit 4: HiddenButton
+ *  - bit 5: PS2_SMBUS_NOTIFY
+ *  - bit 6: PS2CRCCheck
+ */
+#define ETP_NEW_IC_SMBUS_HOST_NOTIFY(fw_version)	\
+		((((fw_version) & 0x0f2000) == 0x0f2000) && \
+		 ((fw_version) & 0x0000ff) > 0)
+
+/*
+ * The base position for one finger, v4 hardware
+ */
+struct finger_pos {
+	unsigned int x;
+	unsigned int y;
+};
+
+struct elantech_device_info {
+	unsigned char capabilities[3];
+	unsigned char samples[3];
+	unsigned char debug;
+	unsigned char hw_version;
+	unsigned char pattern;
+	unsigned int fw_version;
+	unsigned int ic_version;
+	unsigned int product_id;
+	unsigned int x_min;
+	unsigned int y_min;
+	unsigned int x_max;
+	unsigned int y_max;
+	unsigned int x_res;
+	unsigned int y_res;
+	unsigned int x_traces;
+	unsigned int y_traces;
+	unsigned int width;
+	unsigned int bus;
+	bool paritycheck;
+	bool jumpy_cursor;
+	bool reports_pressure;
+	bool crc_enabled;
+	bool set_hw_resolution;
+	bool has_trackpoint;
+	bool has_middle_button;
+	int (*send_cmd)(struct psmouse *psmouse, unsigned char c,
+			unsigned char *param);
+};
+
+struct elantech_data {
+	struct input_dev *tp_dev;	/* Relative device for trackpoint */
+	char tp_phys[32];
+	unsigned char reg_07;
+	unsigned char reg_10;
+	unsigned char reg_11;
+	unsigned char reg_20;
+	unsigned char reg_21;
+	unsigned char reg_22;
+	unsigned char reg_23;
+	unsigned char reg_24;
+	unsigned char reg_25;
+	unsigned char reg_26;
+	unsigned int single_finger_reports;
+	unsigned int y_max;
+	unsigned int width;
+	struct finger_pos mt[ETP_MAX_FINGERS];
+	unsigned char parity[256];
+	struct elantech_device_info info;
+	void (*original_set_rate)(struct psmouse *psmouse, unsigned int rate);
+};
+
+int elantech_detect(struct psmouse *psmouse, bool set_properties);
+int elantech_init_ps2(struct psmouse *psmouse);
+
+#ifdef CONFIG_MOUSE_PS2_ELANTECH
+int elantech_init(struct psmouse *psmouse);
+#else
+static inline int elantech_init(struct psmouse *psmouse)
+{
+	return -ENOSYS;
+}
+#endif /* CONFIG_MOUSE_PS2_ELANTECH */
+
+int elantech_init_smbus(struct psmouse *psmouse);
+
+#endif