[RFC PATCHES 01/17] iommu: Move iommu fault data to linux/iommu.h

[Lu Baolu]

The iommu fault data is currently defined in uapi/linux/iommu.h, but is
only used inside the iommu subsystem. Move it to linux/iommu.h, where it
will be more accessible to kernel drivers.

With this done, uapi/linux/iommu.h becomes empty and can be removed from
the tree. And we can further discuss how to define the iommu fault data
that iommufd could use to route the faults to user space and handle the
fault response if needed.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
 include/linux/iommu.h      | 151 +++++++++++++++++++++++++++++++++-
 include/uapi/linux/iommu.h | 161 -------------------------------------
 MAINTAINERS                |   1 -
 3 files changed, 150 insertions(+), 163 deletions(-)
 delete mode 100644 include/uapi/linux/iommu.h

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8ff1bb3a4e1a..d6a93de7d1dd 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -13,7 +13,6 @@
 #include <linux/errno.h>
 #include <linux/err.h>
 #include <linux/of.h>
-#include <uapi/linux/iommu.h>
 #include <uapi/linux/iommufd.h>
 
 #define IOMMU_READ	(1 << 0)
@@ -43,6 +42,156 @@ struct iommu_sva;
 struct iommu_fault_event;
 struct iommu_dma_cookie;
 
+#define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
+#define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
+#define IOMMU_FAULT_PERM_EXEC	(1 << 2) /* exec */
+#define IOMMU_FAULT_PERM_PRIV	(1 << 3) /* privileged */
+
+/* Generic fault types, can be expanded IRQ remapping fault */
+enum iommu_fault_type {
+	IOMMU_FAULT_DMA_UNRECOV = 1,	/* unrecoverable fault */
+	IOMMU_FAULT_PAGE_REQ,		/* page request fault */
+};
+
+enum iommu_fault_reason {
+	IOMMU_FAULT_REASON_UNKNOWN = 0,
+
+	/* Could not access the PASID table (fetch caused external abort) */
+	IOMMU_FAULT_REASON_PASID_FETCH,
+
+	/* PASID entry is invalid or has configuration errors */
+	IOMMU_FAULT_REASON_BAD_PASID_ENTRY,
+
+	/*
+	 * PASID is out of range (e.g. exceeds the maximum PASID
+	 * supported by the IOMMU) or disabled.
+	 */
+	IOMMU_FAULT_REASON_PASID_INVALID,
+
+	/*
+	 * An external abort occurred fetching (or updating) a translation
+	 * table descriptor
+	 */
+	IOMMU_FAULT_REASON_WALK_EABT,
+
+	/*
+	 * Could not access the page table entry (Bad address),
+	 * actual translation fault
+	 */
+	IOMMU_FAULT_REASON_PTE_FETCH,
+
+	/* Protection flag check failed */
+	IOMMU_FAULT_REASON_PERMISSION,
+
+	/* access flag check failed */
+	IOMMU_FAULT_REASON_ACCESS,
+
+	/* Output address of a translation stage caused Address Size fault */
+	IOMMU_FAULT_REASON_OOR_ADDRESS,
+};
+
+/**
+ * struct iommu_fault_unrecoverable - Unrecoverable fault data
+ * @reason: reason of the fault, from &enum iommu_fault_reason
+ * @flags: parameters of this fault (IOMMU_FAULT_UNRECOV_* values)
+ * @pasid: Process Address Space ID
+ * @perm: requested permission access using by the incoming transaction
+ *        (IOMMU_FAULT_PERM_* values)
+ * @addr: offending page address
+ * @fetch_addr: address that caused a fetch abort, if any
+ */
+struct iommu_fault_unrecoverable {
+	__u32	reason;
+#define IOMMU_FAULT_UNRECOV_PASID_VALID		(1 << 0)
+#define IOMMU_FAULT_UNRECOV_ADDR_VALID		(1 << 1)
+#define IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID	(1 << 2)
+	__u32	flags;
+	__u32	pasid;
+	__u32	perm;
+	__u64	addr;
+	__u64	fetch_addr;
+};
+
+/**
+ * struct iommu_fault_page_request - Page Request data
+ * @flags: encodes whether the corresponding fields are valid and whether this
+ *         is the last page in group (IOMMU_FAULT_PAGE_REQUEST_* values).
+ *         When IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID is set, the page response
+ *         must have the same PASID value as the page request. When it is clear,
+ *         the page response should not have a PASID.
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @perm: requested page permissions (IOMMU_FAULT_PERM_* values)
+ * @addr: page address
+ * @private_data: device-specific private information
+ */
+struct iommu_fault_page_request {
+#define IOMMU_FAULT_PAGE_REQUEST_PASID_VALID	(1 << 0)
+#define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE	(1 << 1)
+#define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA	(1 << 2)
+#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID	(1 << 3)
+	__u32	flags;
+	__u32	pasid;
+	__u32	grpid;
+	__u32	perm;
+	__u64	addr;
+	__u64	private_data[2];
+};
+
+/**
+ * struct iommu_fault - Generic fault data
+ * @type: fault type from &enum iommu_fault_type
+ * @padding: reserved for future use (should be zero)
+ * @event: fault event, when @type is %IOMMU_FAULT_DMA_UNRECOV
+ * @prm: Page Request message, when @type is %IOMMU_FAULT_PAGE_REQ
+ * @padding2: sets the fault size to allow for future extensions
+ */
+struct iommu_fault {
+	__u32	type;
+	__u32	padding;
+	union {
+		struct iommu_fault_unrecoverable event;
+		struct iommu_fault_page_request prm;
+		__u8 padding2[56];
+	};
+};
+
+/**
+ * enum iommu_page_response_code - Return status of fault handlers
+ * @IOMMU_PAGE_RESP_SUCCESS: Fault has been handled and the page tables
+ *	populated, retry the access. This is "Success" in PCI PRI.
+ * @IOMMU_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from
+ *	this device if possible. This is "Response Failure" in PCI PRI.
+ * @IOMMU_PAGE_RESP_INVALID: Could not handle this fault, don't retry the
+ *	access. This is "Invalid Request" in PCI PRI.
+ */
+enum iommu_page_response_code {
+	IOMMU_PAGE_RESP_SUCCESS = 0,
+	IOMMU_PAGE_RESP_INVALID,
+	IOMMU_PAGE_RESP_FAILURE,
+};
+
+/**
+ * struct iommu_page_response - Generic page response information
+ * @argsz: User filled size of this data
+ * @version: API version of this structure
+ * @flags: encodes whether the corresponding fields are valid
+ *         (IOMMU_FAULT_PAGE_RESPONSE_* values)
+ * @pasid: Process Address Space ID
+ * @grpid: Page Request Group Index
+ * @code: response code from &enum iommu_page_response_code
+ */
+struct iommu_page_response {
+	__u32	argsz;
+#define IOMMU_PAGE_RESP_VERSION_1	1
+	__u32	version;
+#define IOMMU_PAGE_RESP_PASID_VALID	(1 << 0)
+	__u32	flags;
+	__u32	pasid;
+	__u32	grpid;
+	__u32	code;
+};
+
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
 #define IOMMU_FAULT_WRITE	0x1
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
deleted file mode 100644
index 65d8b0234f69..000000000000
--- a/include/uapi/linux/iommu.h
+++ /dev/null
@@ -1,161 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * IOMMU user API definitions
- */
-
-#ifndef _UAPI_IOMMU_H
-#define _UAPI_IOMMU_H
-
-#include <linux/types.h>
-
-#define IOMMU_FAULT_PERM_READ	(1 << 0) /* read */
-#define IOMMU_FAULT_PERM_WRITE	(1 << 1) /* write */
-#define IOMMU_FAULT_PERM_EXEC	(1 << 2) /* exec */
-#define IOMMU_FAULT_PERM_PRIV	(1 << 3) /* privileged */
-
-/* Generic fault types, can be expanded IRQ remapping fault */
-enum iommu_fault_type {
-	IOMMU_FAULT_DMA_UNRECOV = 1,	/* unrecoverable fault */
-	IOMMU_FAULT_PAGE_REQ,		/* page request fault */
-};
-
-enum iommu_fault_reason {
-	IOMMU_FAULT_REASON_UNKNOWN = 0,
-
-	/* Could not access the PASID table (fetch caused external abort) */
-	IOMMU_FAULT_REASON_PASID_FETCH,
-
-	/* PASID entry is invalid or has configuration errors */
-	IOMMU_FAULT_REASON_BAD_PASID_ENTRY,
-
-	/*
-	 * PASID is out of range (e.g. exceeds the maximum PASID
-	 * supported by the IOMMU) or disabled.
-	 */
-	IOMMU_FAULT_REASON_PASID_INVALID,
-
-	/*
-	 * An external abort occurred fetching (or updating) a translation
-	 * table descriptor
-	 */
-	IOMMU_FAULT_REASON_WALK_EABT,
-
-	/*
-	 * Could not access the page table entry (Bad address),
-	 * actual translation fault
-	 */
-	IOMMU_FAULT_REASON_PTE_FETCH,
-
-	/* Protection flag check failed */
-	IOMMU_FAULT_REASON_PERMISSION,
-
-	/* access flag check failed */
-	IOMMU_FAULT_REASON_ACCESS,
-
-	/* Output address of a translation stage caused Address Size fault */
-	IOMMU_FAULT_REASON_OOR_ADDRESS,
-};
-
-/**
- * struct iommu_fault_unrecoverable - Unrecoverable fault data
- * @reason: reason of the fault, from &enum iommu_fault_reason
- * @flags: parameters of this fault (IOMMU_FAULT_UNRECOV_* values)
- * @pasid: Process Address Space ID
- * @perm: requested permission access using by the incoming transaction
- *        (IOMMU_FAULT_PERM_* values)
- * @addr: offending page address
- * @fetch_addr: address that caused a fetch abort, if any
- */
-struct iommu_fault_unrecoverable {
-	__u32	reason;
-#define IOMMU_FAULT_UNRECOV_PASID_VALID		(1 << 0)
-#define IOMMU_FAULT_UNRECOV_ADDR_VALID		(1 << 1)
-#define IOMMU_FAULT_UNRECOV_FETCH_ADDR_VALID	(1 << 2)
-	__u32	flags;
-	__u32	pasid;
-	__u32	perm;
-	__u64	addr;
-	__u64	fetch_addr;
-};
-
-/**
- * struct iommu_fault_page_request - Page Request data
- * @flags: encodes whether the corresponding fields are valid and whether this
- *         is the last page in group (IOMMU_FAULT_PAGE_REQUEST_* values).
- *         When IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID is set, the page response
- *         must have the same PASID value as the page request. When it is clear,
- *         the page response should not have a PASID.
- * @pasid: Process Address Space ID
- * @grpid: Page Request Group Index
- * @perm: requested page permissions (IOMMU_FAULT_PERM_* values)
- * @addr: page address
- * @private_data: device-specific private information
- */
-struct iommu_fault_page_request {
-#define IOMMU_FAULT_PAGE_REQUEST_PASID_VALID	(1 << 0)
-#define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE	(1 << 1)
-#define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA	(1 << 2)
-#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID	(1 << 3)
-	__u32	flags;
-	__u32	pasid;
-	__u32	grpid;
-	__u32	perm;
-	__u64	addr;
-	__u64	private_data[2];
-};
-
-/**
- * struct iommu_fault - Generic fault data
- * @type: fault type from &enum iommu_fault_type
- * @padding: reserved for future use (should be zero)
- * @event: fault event, when @type is %IOMMU_FAULT_DMA_UNRECOV
- * @prm: Page Request message, when @type is %IOMMU_FAULT_PAGE_REQ
- * @padding2: sets the fault size to allow for future extensions
- */
-struct iommu_fault {
-	__u32	type;
-	__u32	padding;
-	union {
-		struct iommu_fault_unrecoverable event;
-		struct iommu_fault_page_request prm;
-		__u8 padding2[56];
-	};
-};
-
-/**
- * enum iommu_page_response_code - Return status of fault handlers
- * @IOMMU_PAGE_RESP_SUCCESS: Fault has been handled and the page tables
- *	populated, retry the access. This is "Success" in PCI PRI.
- * @IOMMU_PAGE_RESP_FAILURE: General error. Drop all subsequent faults from
- *	this device if possible. This is "Response Failure" in PCI PRI.
- * @IOMMU_PAGE_RESP_INVALID: Could not handle this fault, don't retry the
- *	access. This is "Invalid Request" in PCI PRI.
- */
-enum iommu_page_response_code {
-	IOMMU_PAGE_RESP_SUCCESS = 0,
-	IOMMU_PAGE_RESP_INVALID,
-	IOMMU_PAGE_RESP_FAILURE,
-};
-
-/**
- * struct iommu_page_response - Generic page response information
- * @argsz: User filled size of this data
- * @version: API version of this structure
- * @flags: encodes whether the corresponding fields are valid
- *         (IOMMU_FAULT_PAGE_RESPONSE_* values)
- * @pasid: Process Address Space ID
- * @grpid: Page Request Group Index
- * @code: response code from &enum iommu_page_response_code
- */
-struct iommu_page_response {
-	__u32	argsz;
-#define IOMMU_PAGE_RESP_VERSION_1	1
-	__u32	version;
-#define IOMMU_PAGE_RESP_PASID_VALID	(1 << 0)
-	__u32	flags;
-	__u32	pasid;
-	__u32	grpid;
-	__u32	code;
-};
-
-#endif /* _UAPI_IOMMU_H */
diff --git a/MAINTAINERS b/MAINTAINERS
index 7e0b87d5aa2e..5f0bb02cfbb3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10837,7 +10837,6 @@ F:	drivers/iommu/
 F:	include/linux/iommu.h
 F:	include/linux/iova.h
 F:	include/linux/of_iommu.h
-F:	include/uapi/linux/iommu.h
 
 IOSYS-MAP HELPERS
 M:	Thomas Zimmermann <tzimmermann@xxxxxxx>
-- 
2.34.1