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.

5 files changed, 329 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml b/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml
new file mode 100644
index 000000000..c34b86bb7
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/brcm,bcm4751.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/brcm,bcm4751.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Broadcom BCM4751 family GNSS Receiver
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+  - Linus Walleij <linusw@kernel.org>
+
+description:
+  Broadcom GPS chips can be used over the UART or I2C bus. The UART
+  bus requires CTS/RTS support. The number of the capsule is more
+  elaborate than the compatibles BCM4751 may be printed
+  BCM4751IFBG for example.
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - brcm,bcm4751
+      - brcm,bcm4752
+      - brcm,bcm4753
+
+  reg:
+    description:
+      The I2C Address, not required on UART buses.
+
+  vdd-auxin-supply:
+    description:
+      Main voltage supply, pin name VDD_AUXIN, typically connected
+      directly to a battery such as LiIon 3.8V battery or a 2.6V supply.
+
+  vddio-supply:
+    description:
+      IO voltage supply, pin name VDDIO, typically 1.8V
+
+  reset-gpios:
+    maxItems: 1
+    description: An optional active low reset line, should be flagged with
+      GPIO_ACTIVE_LOW.
+
+  enable-gpios:
+    description: Enable GPIO line, connected to pins named REGPU or NSTANDBY.
+      If the line is active low such as NSTANDBY, it should be tagged
+      GPIO_ACTIVE_LOW.
+
+required:
+  - compatible
+  - enable-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+        gnss {
+            compatible = "brcm,bcm4751";
+            vdd-auxin-supply = <&vbat>;
+            reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+            enable-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+            current-speed = <38400>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/gnss-common.yaml b/Documentation/devicetree/bindings/gnss/gnss-common.yaml
new file mode 100644
index 000000000..354c05240
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/gnss-common.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/gnss-common.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Common Properties for Global Navigation Satellite Systems (GNSS)
+  receiver devices
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description: |
+  This document defines device tree properties common to Global Navigation
+  Satellite System receivers.
+
+properties:
+  $nodename:
+    pattern: "^gnss(@.*)?$"
+
+  lna-supply:
+    description: A separate regulator supplying power for the Low Noise
+      Amplifier (LNA). This is an amplifier connected between the GNSS
+      device and the receiver antenna.
+
+  enable-gpios:
+    description: A GPIO line that will enable the GNSS receiver when
+      asserted. If this line is active low, the GPIO phandle should
+      consequently be tagged with the GPIO_ACTIVE_LOW flag so the operating
+      system can rely on asserting the line to enable the GNSS device.
+    maxItems: 1
+
+  timepulse-gpios:
+    description: Timepulse signal
+    maxItems: 1
+
+additionalProperties: true
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+      gnss {
+        compatible = "u-blox,neo-8";
+        vcc-supply = <&gnss_reg>;
+        timepulse-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+        current-speed = <4800>;
+      };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/mediatek.yaml b/Documentation/devicetree/bindings/gnss/mediatek.yaml
new file mode 100644
index 000000000..2b9e5be4e
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/mediatek.yaml
@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/mediatek.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Mediatek GNSS Receiver
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description:
+  Mediatek chipsets are used in GNSS-receiver modules produced by several
+  vendors and can use a UART interface.
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+properties:
+  compatible:
+    const: globaltop,pa6h
+
+  vcc-supply:
+    description:
+      Main voltage regulator, pin name VCC.
+
+  reset-gpios:
+    maxItems: 1
+    description: An optional reset line, with names such as RESET or NRESET.
+      If the line is active low it should be flagged with GPIO_ACTIVE_LOW.
+
+  timepulse-gpios:
+    description: Comes with pin names such as PPS1 or 1PPS.
+
+  gnss-fix-gpios:
+    maxItems: 1
+    description: GPIO used to determine device position fix state, pin names
+      FIX or 3D_FIX.
+
+  vbackup-supply:
+    description:
+      Regulator providing backup voltage, pin names such as VBAT or VBACKUP.
+
+required:
+  - compatible
+  - vcc-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+        gnss {
+            compatible = "globaltop,pa6h";
+            vcc-supply = <&vcc_3v3>;
+            reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/sirfstar.yaml b/Documentation/devicetree/bindings/gnss/sirfstar.yaml
new file mode 100644
index 000000000..7e5da89a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/sirfstar.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/sirfstar.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SiRFstar GNSS Receiver
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description:
+  The SiRFstar GNSS receivers have incarnated over the years in different
+  chips, starting from the SiRFstarIII which was a chip that was introduced in
+  2004 and used in a lot of dedicated GPS devices. In 2009 SiRF was acquired
+  by CSR (Cambridge Silicon Radio) and in 2012 the CSR GPS business was
+  acquired by Samsung, while some products remained with CSR. In 2014 CSR
+  was acquired by Qualcomm who still sell some of the SiRF products.
+
+  SiRF chips can be used over UART, I2C or SPI buses.
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - csr,gsd4t
+      - csr,csrg05ta03-icje-r
+      - fastrax,uc430
+      - linx,r4
+      - wi2wi,w2sg0004
+      - wi2wi,w2sg0008i
+      - wi2wi,w2sg0084i
+
+  reg:
+    description:
+      The I2C Address, SPI chip select address. Not required on UART buses.
+
+  vcc-supply:
+    description:
+      Main voltage regulator, pin names such as 3V3_IN, VCC, VDD.
+
+  reset-gpios:
+    maxItems: 1
+    description: An optional active low reset line, should be flagged with
+      GPIO_ACTIVE_LOW.
+
+  sirf,onoff-gpios:
+    maxItems: 1
+    description: GPIO used to power on and off device, pin name ON_OFF.
+
+  sirf,wakeup-gpios:
+    maxItems: 1
+    description: GPIO used to determine device power state, pin names such
+      as RFPWRUP, WAKEUP.
+
+required:
+  - compatible
+  - vcc-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    serial {
+        gnss {
+            compatible = "wi2wi,w2sg0084i";
+            vcc-supply = <&gnss_vcc_reg>;
+            reset-gpios = <&gpio0 15 GPIO_ACTIVE_LOW>;
+            sirf,onoff-gpios = <&gpio0 16 GPIO_ACTIVE_HIGH>;
+            sirf,wakeup-gpios = <&gpio0 17 GPIO_ACTIVE_HIGH>;
+            current-speed = <38400>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
new file mode 100644
index 000000000..b349b7bc0
--- /dev/null
+++ b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gnss/u-blox,neo-6m.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: u-blox GNSS receiver
+
+allOf:
+  - $ref: gnss-common.yaml#
+  - $ref: /schemas/serial/serial-peripheral-props.yaml#
+
+maintainers:
+  - Johan Hovold <johan@kernel.org>
+
+description: >
+  The u-blox GNSS receivers can use UART, DDC (I2C), SPI and USB interfaces.
+
+properties:
+  compatible:
+    oneOf:
+      - enum:
+          - u-blox,neo-6m
+          - u-blox,neo-8
+          - u-blox,neo-m8
+      - items:
+          - const: u-blox,neo-m9
+          - const: u-blox,neo-m8
+
+  reg:
+    description: >
+      The DDC Slave Address, SPI chip select address, the number of the USB hub
+      port or the USB host-controller port to which this device is attached,
+      depending on the bus used. Required for the DDC, SPI or USB busses.
+
+  reset-gpios:
+    maxItems: 1
+
+  safeboot-gpios:
+    maxItems: 1
+
+  vcc-supply:
+    description: >
+      Main voltage regulator
+
+  u-blox,extint-gpios:
+    maxItems: 1
+    description: >
+      GPIO connected to the "external interrupt" input pin
+
+  v-bckp-supply:
+    description: >
+      Backup voltage regulator
+
+required:
+  - compatible
+  - vcc-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    serial {
+        gnss {
+            compatible = "u-blox,neo-8";
+            v-bckp-supply = <&gnss_v_bckp_reg>;
+            vcc-supply = <&gnss_vcc_reg>;
+            reset-gpios = <&gpio 1 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+            safeboot-gpios = <&gpio 2 (GPIO_ACTIVE_LOW | GPIO_OPEN_DRAIN)>;
+        };
+    };