[RFC PATCH v3 1/6] uapi: add goldfish_address_space userspace ABI header

[Wenzhao Liao]

The external goldfish address-space driver exposes its userspace
contract through a dedicated header. Land the ioctl definitions in
include/uapi/linux so the Rust driver can depend on an in-tree UAPI
surface instead of carrying an external private header.

This RFC intentionally narrows the first upstream step to the
open/release/ioctl ABI subset. Userspace mmap and PING_WITH_DATA stay
out of this series until they have their own review and validation
story.

Signed-off-by: Wenzhao Liao <wenzhaoliao@xxxxxxxxxx>
---
 MAINTAINERS                                 |  8 +++
 include/uapi/linux/goldfish_address_space.h | 54 +++++++++++++++++++++
 2 files changed, 62 insertions(+)
 create mode 100644 include/uapi/linux/goldfish_address_space.h

diff --git a/MAINTAINERS b/MAINTAINERS
index a62f6af55c3a..800b2fe0e648 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1882,6 +1882,14 @@ S:	Supported
 F:	Documentation/devicetree/bindings/interrupt-controller/google,goldfish-pic.yaml
 F:	drivers/irqchip/irq-goldfish-pic.c
 
+ANDROID GOLDFISH ADDRESS SPACE DRIVER
+M:	Wenzhao Liao <wenzhaoliao@xxxxxxxxxx>
+L:	linux-kernel@xxxxxxxxxxxxxxx
+L:	linux-pci@xxxxxxxxxxxxxxx
+L:	rust-for-linux@xxxxxxxxxxxxxxx
+S:	Maintained
+F:	include/uapi/linux/goldfish_address_space.h
+
 ANDROID GOLDFISH RTC DRIVER
 M:	Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
 S:	Supported
diff --git a/include/uapi/linux/goldfish_address_space.h b/include/uapi/linux/goldfish_address_space.h
new file mode 100644
index 000000000000..b782d82f53df
--- /dev/null
+++ b/include/uapi/linux/goldfish_address_space.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _UAPI_LINUX_GOLDFISH_ADDRESS_SPACE_H
+#define _UAPI_LINUX_GOLDFISH_ADDRESS_SPACE_H
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+#define GOLDFISH_ADDRESS_SPACE_DEVICE_NAME "goldfish_address_space"
+
+struct goldfish_address_space_allocate_block {
+	__u64 size;
+	__u64 offset;
+	__u64 phys_addr;
+};
+
+struct goldfish_address_space_ping {
+	__u64 offset;
+	__u64 size;
+	__u64 metadata;
+	__u32 version;
+	__u32 wait_fd;
+	__u32 wait_flags;
+	__u32 direction;
+};
+
+struct goldfish_address_space_claim_shared {
+	__u64 offset;
+	__u64 size;
+};
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_MAGIC 'G'
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_OP(OP, T) \
+	_IOWR(GOLDFISH_ADDRESS_SPACE_IOCTL_MAGIC, OP, T)
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_ALLOCATE_BLOCK \
+	GOLDFISH_ADDRESS_SPACE_IOCTL_OP(10, \
+		struct goldfish_address_space_allocate_block)
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_DEALLOCATE_BLOCK \
+	GOLDFISH_ADDRESS_SPACE_IOCTL_OP(11, __u64)
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_PING \
+	GOLDFISH_ADDRESS_SPACE_IOCTL_OP(12, \
+		struct goldfish_address_space_ping)
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_CLAIM_SHARED \
+	GOLDFISH_ADDRESS_SPACE_IOCTL_OP(13, \
+		struct goldfish_address_space_claim_shared)
+
+#define GOLDFISH_ADDRESS_SPACE_IOCTL_UNCLAIM_SHARED \
+	GOLDFISH_ADDRESS_SPACE_IOCTL_OP(14, __u64)
+
+#endif /* _UAPI_LINUX_GOLDFISH_ADDRESS_SPACE_H */
-- 
2.34.1