firmware: arm_ffa: Add support for MEM_* interfaces

Most of the MEM_* APIs share the same parameters, so they can be
generalised. Currently only MEM_SHARE is implemented and the user space
interface for that is not added yet.

Link: https://lore.kernel.org/r/20210521151033.181846-6-sudeep.holla@arm.com
Tested-by: Jens Wiklander <jens.wiklander@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

include/linux/arm_ffa.h

@@ -116,6 +116,142 @@ struct ffa_send_direct_data {
 	unsigned long data4; /* w7/x7 */
 };
 
+struct ffa_mem_region_addr_range {
+	/* The base IPA of the constituent memory region, aligned to 4 kiB */
+	u64 address;
+	/* The number of 4 kiB pages in the constituent memory region. */
+	u32 pg_cnt;
+	u32 reserved;
+};
+
+struct ffa_composite_mem_region {
+	/*
+	 * The total number of 4 kiB pages included in this memory region. This
+	 * must be equal to the sum of page counts specified in each
+	 * `struct ffa_mem_region_addr_range`.
+	 */
+	u32 total_pg_cnt;
+	/* The number of constituents included in this memory region range */
+	u32 addr_range_cnt;
+	u64 reserved;
+	/** An array of `addr_range_cnt` memory region constituents. */
+	struct ffa_mem_region_addr_range constituents[];
+};
+
+struct ffa_mem_region_attributes {
+	/* The ID of the VM to which the memory is being given or shared. */
+	u16 receiver;
+	/*
+	 * The permissions with which the memory region should be mapped in the
+	 * receiver's page table.
+	 */
+#define FFA_MEM_EXEC		BIT(3)
+#define FFA_MEM_NO_EXEC		BIT(2)
+#define FFA_MEM_RW		BIT(1)
+#define FFA_MEM_RO		BIT(0)
+	u8 attrs;
+	/*
+	 * Flags used during FFA_MEM_RETRIEVE_REQ and FFA_MEM_RETRIEVE_RESP
+	 * for memory regions with multiple borrowers.
+	 */
+#define FFA_MEM_RETRIEVE_SELF_BORROWER	BIT(0)
+	u8 flag;
+	u32 composite_off;
+	/*
+	 * Offset in bytes from the start of the outer `ffa_memory_region` to
+	 * an `struct ffa_mem_region_addr_range`.
+	 */
+	u64 reserved;
+};
+
+struct ffa_mem_region {
+	/* The ID of the VM/owner which originally sent the memory region */
+	u16 sender_id;
+#define FFA_MEM_NORMAL		BIT(5)
+#define FFA_MEM_DEVICE		BIT(4)
+
+#define FFA_MEM_WRITE_BACK	(3 << 2)
+#define FFA_MEM_NON_CACHEABLE	(1 << 2)
+
+#define FFA_DEV_nGnRnE		(0 << 2)
+#define FFA_DEV_nGnRE		(1 << 2)
+#define FFA_DEV_nGRE		(2 << 2)
+#define FFA_DEV_GRE		(3 << 2)
+
+#define FFA_MEM_NON_SHAREABLE	(0)
+#define FFA_MEM_OUTER_SHAREABLE	(2)
+#define FFA_MEM_INNER_SHAREABLE	(3)
+	u8 attributes;
+	u8 reserved_0;
+/*
+ * Clear memory region contents after unmapping it from the sender and
+ * before mapping it for any receiver.
+ */
+#define FFA_MEM_CLEAR			BIT(0)
+/*
+ * Whether the hypervisor may time slice the memory sharing or retrieval
+ * operation.
+ */
+#define FFA_TIME_SLICE_ENABLE		BIT(1)
+
+#define FFA_MEM_RETRIEVE_TYPE_IN_RESP	(0 << 3)
+#define FFA_MEM_RETRIEVE_TYPE_SHARE	(1 << 3)
+#define FFA_MEM_RETRIEVE_TYPE_LEND	(2 << 3)
+#define FFA_MEM_RETRIEVE_TYPE_DONATE	(3 << 3)
+
+#define FFA_MEM_RETRIEVE_ADDR_ALIGN_HINT	BIT(9)
+#define FFA_MEM_RETRIEVE_ADDR_ALIGN(x)		((x) << 5)
+	/* Flags to control behaviour of the transaction. */
+	u32 flags;
+#define HANDLE_LOW_MASK		GENMASK_ULL(31, 0)
+#define HANDLE_HIGH_MASK	GENMASK_ULL(63, 32)
+#define HANDLE_LOW(x)		((u32)(FIELD_GET(HANDLE_LOW_MASK, (x))))
+#define	HANDLE_HIGH(x)		((u32)(FIELD_GET(HANDLE_HIGH_MASK, (x))))
+
+#define PACK_HANDLE(l, h)		\
+	(FIELD_PREP(HANDLE_LOW_MASK, (l)) | FIELD_PREP(HANDLE_HIGH_MASK, (h)))
+	/*
+	 * A globally-unique ID assigned by the hypervisor for a region
+	 * of memory being sent between VMs.
+	 */
+	u64 handle;
+	/*
+	 * An implementation defined value associated with the receiver and the
+	 * memory region.
+	 */
+	u64 tag;
+	u32 reserved_1;
+	/*
+	 * The number of `ffa_mem_region_attributes` entries included in this
+	 * transaction.
+	 */
+	u32 ep_count;
+	/*
+	 * An array of endpoint memory access descriptors.
+	 * Each one specifies a memory region offset, an endpoint and the
+	 * attributes with which this memory region should be mapped in that
+	 * endpoint's page table.
+	 */
+	struct ffa_mem_region_attributes ep_mem_access[];
+};
+
+#define	COMPOSITE_OFFSET(x)	\
+	(offsetof(struct ffa_mem_region, ep_mem_access[x]))
+#define CONSTITUENTS_OFFSET(x)	\
+	(offsetof(struct ffa_composite_mem_region, constituents[x]))
+#define COMPOSITE_CONSTITUENTS_OFFSET(x, y)	\
+	(COMPOSITE_OFFSET(x) + CONSTITUENTS_OFFSET(y))
+
+struct ffa_mem_ops_args {
+	bool use_txbuf;
+	u32 nattrs;
+	u32 flags;
+	u64 tag;
+	u64 g_handle;
+	struct scatterlist *sg;
+	struct ffa_mem_region_attributes *attrs;
+};
+
 struct ffa_dev_ops {
 	u32 (*api_version_get)(void);
 	int (*partition_info_get)(const char *uuid_str,
@@ -123,6 +259,9 @@ struct ffa_dev_ops {
 	void (*mode_32bit_set)(struct ffa_device *dev);
 	int (*sync_send_receive)(struct ffa_device *dev,
 				 struct ffa_send_direct_data *data);
+	int (*memory_reclaim)(u64 g_handle, u32 flags);
+	int (*memory_share)(struct ffa_device *dev,
+			    struct ffa_mem_ops_args *args);
 };
 
 #endif /* _LINUX_ARM_FFA_H */