[PATCH v4 03/27] cxl: Move component register defines to uapi/cxl/cxl_regs.h

From: Manish Honap <[email protected]>

The CXL component and HDM decoder register layout is spec-defined and is
needed by consumers outside the CXL subsystem such as vfio-cxl, which
cannot include the private drivers/cxl/cxl.h. Move those defines to a new
uapi header, the way PCI register offsets live in uapi pci_regs.h, and
include it from drivers/cxl/cxl.h so existing users are unchanged.

No functional change; the GENMASK and BIT forms are written as plain
values as an uAPI header requirement.

Signed-off-by: Manish Honap <[email protected]>
---
 MAINTAINERS                 |  1 +
 drivers/cxl/cxl.h           | 47 +-----------------------------
 include/uapi/cxl/cxl_regs.h | 58 +++++++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 46 deletions(-)
 create mode 100644 include/uapi/cxl/cxl_regs.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 5114e6db7307..c665bf8f1a28 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6528,6 +6528,7 @@ F:	Documentation/driver-api/cxl
 F:	Documentation/userspace-api/fwctl/fwctl-cxl.rst
 F:	drivers/cxl/
 F:	include/cxl/
+F:	include/uapi/cxl/
 F:	include/uapi/linux/cxl_mem.h
 F:	tools/testing/cxl/
 
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index c795cce0fcbc..2893b2427be1 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -13,6 +13,7 @@
 #include <linux/io.h>
 #include <linux/range.h>
 #include <cxl/cxl.h>
+#include <cxl/cxl_regs.h>
 
 extern const struct nvdimm_security_ops *cxl_security_ops;
 
@@ -24,52 +25,6 @@ extern const struct nvdimm_security_ops *cxl_security_ops;
  * (port-driver, region-driver, nvdimm object-drivers... etc).
  */
 
-/* CXL 2.0 8.2.4 CXL Component Register Layout and Definition */
-#define CXL_COMPONENT_REG_BLOCK_SIZE SZ_64K
-
-/* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers*/
-#define CXL_CM_OFFSET 0x1000
-#define CXL_CM_CAP_HDR_OFFSET 0x0
-#define   CXL_CM_CAP_HDR_ID_MASK GENMASK(15, 0)
-#define     CM_CAP_HDR_CAP_ID 1
-#define   CXL_CM_CAP_HDR_VERSION_MASK GENMASK(19, 16)
-#define     CM_CAP_HDR_CAP_VERSION 1
-#define   CXL_CM_CAP_HDR_CACHE_MEM_VERSION_MASK GENMASK(23, 20)
-#define     CM_CAP_HDR_CACHE_MEM_VERSION 1
-#define   CXL_CM_CAP_HDR_ARRAY_SIZE_MASK GENMASK(31, 24)
-#define CXL_CM_CAP_PTR_MASK GENMASK(31, 20)
-
-#define   CXL_CM_CAP_CAP_ID_RAS 0x2
-#define   CXL_CM_CAP_CAP_ID_HDM 0x5
-#define   CXL_CM_CAP_CAP_HDM_VERSION 1
-
-/* HDM decoders CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure */
-#define CXL_HDM_DECODER_CAP_OFFSET 0x0
-#define   CXL_HDM_DECODER_COUNT_MASK GENMASK(3, 0)
-#define   CXL_HDM_DECODER_TARGET_COUNT_MASK GENMASK(7, 4)
-#define   CXL_HDM_DECODER_INTERLEAVE_11_8 BIT(8)
-#define   CXL_HDM_DECODER_INTERLEAVE_14_12 BIT(9)
-#define   CXL_HDM_DECODER_INTERLEAVE_3_6_12_WAY BIT(11)
-#define   CXL_HDM_DECODER_INTERLEAVE_16_WAY BIT(12)
-#define CXL_HDM_DECODER_CTRL_OFFSET 0x4
-#define   CXL_HDM_DECODER_ENABLE BIT(1)
-#define CXL_HDM_DECODER0_BASE_LOW_OFFSET(i) (0x20 * (i) + 0x10)
-#define CXL_HDM_DECODER0_BASE_HIGH_OFFSET(i) (0x20 * (i) + 0x14)
-#define CXL_HDM_DECODER0_SIZE_LOW_OFFSET(i) (0x20 * (i) + 0x18)
-#define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(i) (0x20 * (i) + 0x1c)
-#define CXL_HDM_DECODER0_CTRL_OFFSET(i) (0x20 * (i) + 0x20)
-#define   CXL_HDM_DECODER0_CTRL_IG_MASK GENMASK(3, 0)
-#define   CXL_HDM_DECODER0_CTRL_IW_MASK GENMASK(7, 4)
-#define   CXL_HDM_DECODER0_CTRL_LOCK BIT(8)
-#define   CXL_HDM_DECODER0_CTRL_COMMIT BIT(9)
-#define   CXL_HDM_DECODER0_CTRL_COMMITTED BIT(10)
-#define   CXL_HDM_DECODER0_CTRL_COMMIT_ERROR BIT(11)
-#define   CXL_HDM_DECODER0_CTRL_HOSTONLY BIT(12)
-#define CXL_HDM_DECODER0_TL_LOW(i) (0x20 * (i) + 0x24)
-#define CXL_HDM_DECODER0_TL_HIGH(i) (0x20 * (i) + 0x28)
-#define CXL_HDM_DECODER0_SKIP_LOW(i) CXL_HDM_DECODER0_TL_LOW(i)
-#define CXL_HDM_DECODER0_SKIP_HIGH(i) CXL_HDM_DECODER0_TL_HIGH(i)
-
 /* HDM decoder control register constants CXL 3.0 8.2.5.19.7 */
 #define CXL_DECODER_MIN_GRANULARITY 256
 #define CXL_DECODER_MAX_ENCODED_IG 6
diff --git a/include/uapi/cxl/cxl_regs.h b/include/uapi/cxl/cxl_regs.h
new file mode 100644
index 000000000000..04bf790f0fdc
--- /dev/null
+++ b/include/uapi/cxl/cxl_regs.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/* Copyright (c) 2026 NVIDIA Corporation & Affiliates */
+
+#ifndef _UAPI_CXL_REGS_H_
+#define _UAPI_CXL_REGS_H_
+
+/*
+ * CXL Component Register layout from the CXL specification. Kept in uapi so a
+ * VMM can consume the register offsets without a kernel header dependency.
+ */
+
+/* CXL 2.0 8.2.4 CXL Component Register Layout and Definition */
+#define CXL_COMPONENT_REG_BLOCK_SIZE 0x10000
+
+/* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers */
+#define CXL_CM_OFFSET 0x1000
+#define CXL_CM_CAP_HDR_OFFSET 0x0
+#define   CXL_CM_CAP_HDR_ID_MASK 0xffff
+#define     CM_CAP_HDR_CAP_ID 1
+#define   CXL_CM_CAP_HDR_VERSION_MASK 0xf0000
+#define     CM_CAP_HDR_CAP_VERSION 1
+#define   CXL_CM_CAP_HDR_CACHE_MEM_VERSION_MASK 0xf00000
+#define     CM_CAP_HDR_CACHE_MEM_VERSION 1
+#define   CXL_CM_CAP_HDR_ARRAY_SIZE_MASK 0xff000000
+#define CXL_CM_CAP_PTR_MASK 0xfff00000
+
+#define   CXL_CM_CAP_CAP_ID_RAS 0x2
+#define   CXL_CM_CAP_CAP_ID_HDM 0x5
+#define   CXL_CM_CAP_CAP_HDM_VERSION 1
+
+/* HDM decoders CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure */
+#define CXL_HDM_DECODER_CAP_OFFSET 0x0
+#define   CXL_HDM_DECODER_COUNT_MASK 0xf
+#define   CXL_HDM_DECODER_TARGET_COUNT_MASK 0xf0
+#define   CXL_HDM_DECODER_INTERLEAVE_11_8 0x100
+#define   CXL_HDM_DECODER_INTERLEAVE_14_12 0x200
+#define   CXL_HDM_DECODER_INTERLEAVE_3_6_12_WAY 0x800
+#define   CXL_HDM_DECODER_INTERLEAVE_16_WAY 0x1000
+#define CXL_HDM_DECODER_CTRL_OFFSET 0x4
+#define   CXL_HDM_DECODER_ENABLE 0x2
+#define CXL_HDM_DECODER0_BASE_LOW_OFFSET(i) (0x20 * (i) + 0x10)
+#define CXL_HDM_DECODER0_BASE_HIGH_OFFSET(i) (0x20 * (i) + 0x14)
+#define CXL_HDM_DECODER0_SIZE_LOW_OFFSET(i) (0x20 * (i) + 0x18)
+#define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(i) (0x20 * (i) + 0x1c)
+#define CXL_HDM_DECODER0_CTRL_OFFSET(i) (0x20 * (i) + 0x20)
+#define   CXL_HDM_DECODER0_CTRL_IG_MASK 0xf
+#define   CXL_HDM_DECODER0_CTRL_IW_MASK 0xf0
+#define   CXL_HDM_DECODER0_CTRL_LOCK 0x100
+#define   CXL_HDM_DECODER0_CTRL_COMMIT 0x200
+#define   CXL_HDM_DECODER0_CTRL_COMMITTED 0x400
+#define   CXL_HDM_DECODER0_CTRL_COMMIT_ERROR 0x800
+#define   CXL_HDM_DECODER0_CTRL_HOSTONLY 0x1000
+#define CXL_HDM_DECODER0_TL_LOW(i) (0x20 * (i) + 0x24)
+#define CXL_HDM_DECODER0_TL_HIGH(i) (0x20 * (i) + 0x28)
+#define CXL_HDM_DECODER0_SKIP_LOW(i) CXL_HDM_DECODER0_TL_LOW(i)
+#define CXL_HDM_DECODER0_SKIP_HIGH(i) CXL_HDM_DECODER0_TL_HIGH(i)
+
+#endif /* _UAPI_CXL_REGS_H_ */
-- 
2.25.1