[linux-nvidia-6.17-next] Add CXL Type-2 device support, RAS error handling, reset, state save/restore, and interleaving support

.mailmap

@@ -182,6 +182,9 @@ Christian Brauner <brauner@kernel.org> <christian@brauner.io>
 Christian Brauner <brauner@kernel.org> <christian.brauner@canonical.com>
 Christian Brauner <brauner@kernel.org> <christian.brauner@ubuntu.com>
 Christian Marangi <ansuelsmth@gmail.com>
+Christophe Leroy <chleroy@kernel.org> <christophe.leroy@c-s.fr>
+Christophe Leroy <chleroy@kernel.org> <christophe.leroy@csgroup.eu>
+Christophe Leroy <chleroy@kernel.org> <christophe.leroy2@cs-soprasteria.com>
 Christophe Ricard <christophe.ricard@gmail.com>
 Christopher Obbard <christopher.obbard@linaro.org> <chris.obbard@collabora.com>
 Christoph Hellwig <hch@lst.de>

Documentation/ABI/testing/debugfs-cxl

@@ -19,6 +19,20 @@ Description:
 		is returned to the user. The inject_poison attribute is only
 		visible for devices supporting the capability.
 
+		TEST-ONLY INTERFACE: This interface is intended for testing
+		and validation purposes only. It is not a data repair mechanism
+		and should never be used on production systems or live data.
+
+		DATA LOSS RISK: For CXL persistent memory (PMEM) devices,
+		poison injection can result in permanent data loss. Injected
+		poison may render data permanently inaccessible even after
+		clearing, as the clear operation writes zeros and does not
+		recover original data.
+
+		SYSTEM STABILITY RISK: For volatile memory, poison injection
+		can cause kernel crashes, system instability, or unpredictable
+		behavior if the poisoned addresses are accessed by running code
+		or critical kernel structures.
 
 What:		/sys/kernel/debug/cxl/memX/clear_poison
 Date:		April, 2023
@@ -35,6 +49,79 @@ Description:
 		The clear_poison attribute is only visible for devices
 		supporting the capability.
 
+		TEST-ONLY INTERFACE: This interface is intended for testing
+		and validation purposes only. It is not a data repair mechanism
+		and should never be used on production systems or live data.
+
+		CLEAR IS NOT DATA RECOVERY: This operation writes zeros to the
+		specified address range and removes the address from the poison
+		list. It does NOT recover or restore original data that may have
+		been present before poison injection. Any original data at the
+		cleared address is permanently lost and replaced with zeros.
+
+		CLEAR IS NOT A REPAIR MECHANISM: This interface is for testing
+		purposes only and should not be used as a data repair tool.
+		Clearing poison is fundamentally different from data recovery
+		or error correction.
+
+What:		/sys/kernel/debug/cxl/regionX/inject_poison
+Date:		August, 2025
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a Host Physical Address (HPA) is written to this
+		attribute, the region driver translates it to a Device
+		Physical Address (DPA) and identifies the corresponding
+		memdev. It then sends an inject poison command to that memdev
+		at the translated DPA. Refer to the memdev ABI entry at:
+		/sys/kernel/debug/cxl/memX/inject_poison for the detailed
+		behavior. This attribute is only visible if all memdevs
+		participating in the region support both inject and clear
+		poison commands.
+
+		TEST-ONLY INTERFACE: This interface is intended for testing
+		and validation purposes only. It is not a data repair mechanism
+		and should never be used on production systems or live data.
+
+		DATA LOSS RISK: For CXL persistent memory (PMEM) devices,
+		poison injection can result in permanent data loss. Injected
+		poison may render data permanently inaccessible even after
+		clearing, as the clear operation writes zeros and does not
+		recover original data.
+
+		SYSTEM STABILITY RISK: For volatile memory, poison injection
+		can cause kernel crashes, system instability, or unpredictable
+		behavior if the poisoned addresses are accessed by running code
+		or critical kernel structures.
+
+What:		/sys/kernel/debug/cxl/regionX/clear_poison
+Date:		August, 2025
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a Host Physical Address (HPA) is written to this
+		attribute, the region driver translates it to a Device
+		Physical Address (DPA) and identifies the corresponding
+		memdev. It then sends a clear poison command to that memdev
+		at the translated DPA. Refer to the memdev ABI entry at:
+		/sys/kernel/debug/cxl/memX/clear_poison for the detailed
+		behavior. This attribute is only visible if all memdevs
+		participating in the region support both inject and clear
+		poison commands.
+
+		TEST-ONLY INTERFACE: This interface is intended for testing
+		and validation purposes only. It is not a data repair mechanism
+		and should never be used on production systems or live data.
+
+		CLEAR IS NOT DATA RECOVERY: This operation writes zeros to the
+		specified address range and removes the address from the poison
+		list. It does NOT recover or restore original data that may have
+		been present before poison injection. Any original data at the
+		cleared address is permanently lost and replaced with zeros.
+
+		CLEAR IS NOT A REPAIR MECHANISM: This interface is for testing
+		purposes only and should not be used as a data repair tool.
+		Clearing poison is fundamentally different from data recovery
+		or error correction.
+
 What:		/sys/kernel/debug/cxl/einj_types
 Date:		January, 2024
 KernelVersion:	v6.9

Documentation/ABI/testing/sysfs-bus-cxl

@@ -496,8 +496,17 @@ Description:
 		changed, only freed by writing 0. The kernel makes no guarantees
 		that data is maintained over an address space freeing event, and
 		there is no guarantee that a free followed by an allocate
-		results in the same address being allocated.
+		results in the same address being allocated. If extended linear
+		cache is present, the size indicates extended linear cache size
+		plus the CXL region size.
 
+What:		/sys/bus/cxl/devices/regionZ/extended_linear_cache_size
+Date:		October, 2025
+KernelVersion:	v6.19
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(RO) The size of extended linear cache, if there is an extended
+		linear cache. Otherwise the attribute will not be visible.
 
 What:		/sys/bus/cxl/devices/regionZ/mode
 Date:		January, 2023

Documentation/ABI/testing/sysfs-bus-pci

@@ -174,6 +174,28 @@ Description:
 		similiar to writing 1 to their individual "reset" file, so use
 		with caution.
 
+What:		/sys/bus/pci/devices/.../cxl_reset
+Date:		February 2026
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		This attribute is only visible when the device advertises
+		CXL Reset Capable in the CXL DVSEC Capability register
+		(CXL r3.2, section 8.1.3).
+
+		Writing 1 to this file triggers a CXL device reset which
+		affects CXL.cache and CXL.mem state on all CXL functions
+		(i.e. those not listed in the Non-CXL Function Map DVSEC,
+		section 8.1.4), not just CXL.io/PCIe state.  This is
+		separate from the standard PCI reset interface because CXL
+		Reset has different scope.
+
+		The reset will fail with -EBUSY if any CXL regions using this
+		device have drivers bound.  Active regions are torn down as
+		part of the reset sequence.
+
+		This attribute is registered by the CXL core when a CXL device
+		is discovered, independent of which driver binds the PCI device.
+
 What:		/sys/bus/pci/devices/.../vpd
 Date:		February 2008
 Contact:	Ben Hutchings <bwh@kernel.org>

Documentation/devicetree/bindings/arm/amlogic/amlogic,meson-gx-ao-secure.yaml

@@ -34,6 +34,9 @@ properties:
               - amlogic,a4-ao-secure
               - amlogic,c3-ao-secure
               - amlogic,s4-ao-secure
+              - amlogic,s6-ao-secure
+              - amlogic,s7-ao-secure
+              - amlogic,s7d-ao-secure
               - amlogic,t7-ao-secure
           - const: amlogic,meson-gx-ao-secure
           - const: syscon

Documentation/devicetree/bindings/cache/sifive,ccache0.yaml

@@ -48,6 +48,11 @@ properties:
           - const: microchip,mpfs-ccache
           - const: sifive,fu540-c000-ccache
           - const: cache
+      - items:
+          - const: microchip,pic64gx-ccache
+          - const: microchip,mpfs-ccache
+          - const: sifive,fu540-c000-ccache
+          - const: cache
 
   cache-block-size:
     const: 64

Documentation/devicetree/bindings/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml

@@ -0,0 +1,47 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/microchip/microchip,mpfs-mss-top-sysreg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip PolarFire SoC Microprocessor Subsystem (MSS) sysreg register region
+
+maintainers:
+  - Conor Dooley <conor.dooley@microchip.com>
+
+description:
+  An wide assortment of registers that control elements of the MSS on PolarFire
+  SoC, including pinmuxing, resets and clocks among others.
+
+properties:
+  compatible:
+    items:
+      - const: microchip,mpfs-mss-top-sysreg
+      - const: syscon
+
+  reg:
+    maxItems: 1
+
+  '#reset-cells':
+    description:
+      The AHB/AXI peripherals on the PolarFire SoC have reset support, so
+      from CLK_ENVM to CLK_CFM. The reset consumer should specify the
+      desired peripheral via the clock ID in its "resets" phandle cell.
+      See include/dt-bindings/clock/microchip,mpfs-clock.h for the full list
+      of PolarFire clock/reset IDs.
+    const: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    syscon@20002000 {
+      compatible = "microchip,mpfs-mss-top-sysreg", "syscon";
+      reg = <0x20002000 0x1000>;
+      #reset-cells = <1>;
+    };
+

Documentation/driver-api/cxl/allocation/page-allocator.rst

@@ -41,37 +41,6 @@ To simplify this, the page allocator will prefer :code:`ZONE_MOVABLE` over
 will fallback to allocate from :code:`ZONE_NORMAL`.
 
 
-Zone and Node Quirks
-====================
-Let's consider a configuration where the local DRAM capacity is largely onlined
-into :code:`ZONE_NORMAL`, with no :code:`ZONE_MOVABLE` capacity present. The
-CXL capacity has the opposite configuration - all onlined in
-:code:`ZONE_MOVABLE`.
-
-Under the default allocation policy, the page allocator will completely skip
-:code:`ZONE_MOVABLE` as a valid allocation target.  This is because, as of
-Linux v6.15, the page allocator does (approximately) the following: ::
-
-  for (each zone in local_node):
-
-    for (each node in fallback_order):
-
-      attempt_allocation(gfp_flags);
-
-Because the local node does not have :code:`ZONE_MOVABLE`, the CXL node is
-functionally unreachable for direct allocation.  As a result, the only way
-for CXL capacity to be used is via `demotion` in the reclaim path.
-
-This configuration also means that if the DRAM ndoe has :code:`ZONE_MOVABLE`
-capacity - when that capacity is depleted, the page allocator will actually
-prefer CXL :code:`ZONE_MOVABLE` pages over DRAM :code:`ZONE_NORMAL` pages.
-
-We may wish to invert this priority in future Linux versions.
-
-If `demotion` and `swap` are disabled, Linux will begin to cause OOM crashes
-when the DRAM nodes are depleted. See the reclaim section for more details.
-
-
 CGroups and CPUSets
 ===================
 Finally, assuming CXL memory is reachable via the page allocation (i.e. onlined