arm_ffa: introduce Arm FF-A support

Add Arm FF-A support implementing Arm Firmware Framework for Armv8-A v1.0

The Firmware Framework for Arm A-profile processors (FF-A v1.0) [1]
describes interfaces (ABIs) that standardize communication
between the Secure World and Normal World leveraging TrustZone
technology.

This driver uses 64-bit registers as per SMCCCv1.2 spec and comes
on top of the SMCCC layer. The driver provides the FF-A ABIs needed for
querying the FF-A framework from the secure world.

The driver uses SMC32 calling convention which means using the first
32-bit data of the Xn registers.

All supported ABIs come with their 32-bit version except FFA_RXTX_MAP
which has 64-bit version supported.

Both 32-bit and 64-bit direct messaging are supported which allows both
32-bit and 64-bit clients to use the FF-A bus.

FF-A is a discoverable bus and similar to architecture features.
FF-A bus is discovered using ARM_SMCCC_FEATURES mechanism performed
by the PSCI driver.

Clients are able to probe then use the FF-A bus by calling the DM class
searching APIs (e.g: uclass_first_device).

The Secure World is considered as one entity to communicate with
using the FF-A bus. FF-A communication is handled by one device and
one instance (the bus). This FF-A driver takes care of all the
interactions between Normal world and Secure World.

The driver exports its operations to be used by upper layers.

Exported operations:

- ffa_partition_info_get
- ffa_sync_send_receive
- ffa_rxtx_unmap

Generic FF-A methods are implemented in the Uclass (arm-ffa-uclass.c).
Arm specific methods are implemented in the Arm driver (arm-ffa.c).

For more details please refer to the driver documentation [2].

[1]: https://developer.arm.com/documentation/den0077/latest/
[2]: doc/arch/arm64.ffa.rst

Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>

1 files changed, 246 insertions, 0 deletions

diff --git a/include/arm_ffa_priv.h b/include/arm_ffa_priv.h
new file mode 100644
index 00000000000..d564c33c647
--- /dev/null
+++ b/include/arm_ffa_priv.h
@@ -0,0 +1,246 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+ *
+ * Authors:
+ *   Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
+ */
+
+#ifndef __ARM_FFA_PRV_H
+#define __ARM_FFA_PRV_H
+
+#include <mapmem.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+
+/* This header is exclusively used by the FF-A Uclass and FF-A driver(s) */
+
+/* Arm FF-A driver name */
+#define FFA_DRV_NAME "arm_ffa"
+
+/* The FF-A SMC function definitions */
+
+#if CONFIG_IS_ENABLED(SANDBOX)
+
+/* Providing Arm SMCCC declarations to sandbox */
+
+/**
+ * struct sandbox_smccc_1_2_regs - emulated SMC call arguments or results
+ * @a0-a17 argument values from registers 0 to 17
+ */
+struct sandbox_smccc_1_2_regs {
+	ulong a0;
+	ulong a1;
+	ulong a2;
+	ulong a3;
+	ulong a4;
+	ulong a5;
+	ulong a6;
+	ulong a7;
+	ulong a8;
+	ulong a9;
+	ulong a10;
+	ulong a11;
+	ulong a12;
+	ulong a13;
+	ulong a14;
+	ulong a15;
+	ulong a16;
+	ulong a17;
+};
+
+typedef struct sandbox_smccc_1_2_regs ffa_value_t;
+
+#define ARM_SMCCC_FAST_CALL		1UL
+#define ARM_SMCCC_OWNER_STANDARD	4
+#define ARM_SMCCC_SMC_32		0
+#define ARM_SMCCC_SMC_64		1
+#define ARM_SMCCC_TYPE_SHIFT		31
+#define ARM_SMCCC_CALL_CONV_SHIFT	30
+#define ARM_SMCCC_OWNER_MASK		0x3f
+#define ARM_SMCCC_OWNER_SHIFT		24
+#define ARM_SMCCC_FUNC_MASK		0xffff
+
+#define ARM_SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
+	(((type) << ARM_SMCCC_TYPE_SHIFT) | \
+	((calling_convention) << ARM_SMCCC_CALL_CONV_SHIFT) | \
+	(((owner) & ARM_SMCCC_OWNER_MASK) << ARM_SMCCC_OWNER_SHIFT) | \
+	((func_num) & ARM_SMCCC_FUNC_MASK))
+
+#else
+/* CONFIG_ARM64 */
+#include <linux/arm-smccc.h>
+typedef struct arm_smccc_1_2_regs ffa_value_t;
+#endif
+
+/* Defining the function pointer type for the function executing the FF-A ABIs */
+typedef void (*invoke_ffa_fn_t)(ffa_value_t args, ffa_value_t *res);
+
+/* FF-A driver version definitions */
+
+#define MAJOR_VERSION_MASK		GENMASK(30, 16)
+#define MINOR_VERSION_MASK		GENMASK(15, 0)
+#define GET_FFA_MAJOR_VERSION(x)		\
+				((u16)(FIELD_GET(MAJOR_VERSION_MASK, (x))))
+#define GET_FFA_MINOR_VERSION(x)		\
+				((u16)(FIELD_GET(MINOR_VERSION_MASK, (x))))
+#define PACK_VERSION_INFO(major, minor)			\
+	(FIELD_PREP(MAJOR_VERSION_MASK, (major)) |	\
+	 FIELD_PREP(MINOR_VERSION_MASK, (minor)))
+
+#define FFA_MAJOR_VERSION		(1)
+#define FFA_MINOR_VERSION		(0)
+#define FFA_VERSION_1_0		\
+			PACK_VERSION_INFO(FFA_MAJOR_VERSION, FFA_MINOR_VERSION)
+
+/* Endpoint ID mask (u-boot endpoint ID) */
+
+#define GET_SELF_ENDPOINT_ID_MASK		GENMASK(15, 0)
+#define GET_SELF_ENDPOINT_ID(x)		\
+			((u16)(FIELD_GET(GET_SELF_ENDPOINT_ID_MASK, (x))))
+
+#define PREP_SELF_ENDPOINT_ID_MASK		GENMASK(31, 16)
+#define PREP_SELF_ENDPOINT_ID(x)		\
+			(FIELD_PREP(PREP_SELF_ENDPOINT_ID_MASK, (x)))
+
+/* Partition endpoint ID mask  (partition with which u-boot communicates with) */
+
+#define PREP_PART_ENDPOINT_ID_MASK		GENMASK(15, 0)
+#define PREP_PART_ENDPOINT_ID(x)		\
+			(FIELD_PREP(PREP_PART_ENDPOINT_ID_MASK, (x)))
+
+/* Definitions of the Arm FF-A interfaces supported by the Arm FF-A driver */
+
+#define FFA_SMC(calling_convention, func_num)				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, (calling_convention),	\
+			   ARM_SMCCC_OWNER_STANDARD, (func_num))
+
+#define FFA_SMC_32(func_num)				FFA_SMC(ARM_SMCCC_SMC_32, (func_num))
+#define FFA_SMC_64(func_num)				FFA_SMC(ARM_SMCCC_SMC_64, (func_num))
+
+enum ffa_abis {
+	FFA_ERROR                 = 0x60,
+	FFA_SUCCESS               = 0x61,
+	FFA_INTERRUPT             = 0x62,
+	FFA_VERSION               = 0x63,
+	FFA_FEATURES              = 0x64,
+	FFA_RX_RELEASE            = 0x65,
+	FFA_RXTX_MAP              = 0x66,
+	FFA_RXTX_UNMAP            = 0x67,
+	FFA_PARTITION_INFO_GET    = 0x68,
+	FFA_ID_GET                = 0x69,
+	FFA_RUN                   = 0x6d,
+	FFA_MSG_SEND_DIRECT_REQ   = 0x6f,
+	FFA_MSG_SEND_DIRECT_RESP  = 0x70,
+
+	/* To be updated when adding new FFA IDs */
+	FFA_FIRST_ID              = FFA_ERROR, /* Lowest number ID */
+	FFA_LAST_ID               = FFA_MSG_SEND_DIRECT_RESP, /* Highest number ID */
+};
+
+enum ffa_abi_errcode {
+	NOT_SUPPORTED = 1,
+	INVALID_PARAMETERS,
+	NO_MEMORY,
+	BUSY,
+	INTERRUPTED,
+	DENIED,
+	RETRY,
+	ABORTED,
+	MAX_NUMBER_FFA_ERR
+};
+
+extern int ffa_to_std_errmap[MAX_NUMBER_FFA_ERR];
+
+/* Container structure and helper macros to map between an FF-A error and relevant error log */
+struct ffa_abi_errmap {
+	char *err_str[MAX_NUMBER_FFA_ERR];
+};
+
+#define FFA_ERRMAP_COUNT (FFA_LAST_ID - FFA_FIRST_ID + 1)
+#define FFA_ID_TO_ERRMAP_ID(ffa_id) ((ffa_id) - FFA_FIRST_ID)
+
+/**
+ * enum ffa_rxtx_buf_sizes - minimum sizes supported
+ * for the RX/TX buffers
+ */
+enum ffa_rxtx_buf_sizes {
+	RXTX_4K,
+	RXTX_64K,
+	RXTX_16K
+};
+
+/**
+ * struct ffa_rxtxpair - Hosts the RX/TX buffers virtual addresses
+ * @rxbuf:	virtual address of the RX buffer
+ * @txbuf:	virtual address of the TX buffer
+ * @rxtx_min_pages:	RX/TX buffers minimum size in pages
+ *
+ * Hosts the virtual addresses of the mapped RX/TX buffers
+ * These addresses are used by the FF-A functions that use the RX/TX buffers
+ */
+struct ffa_rxtxpair {
+	void *rxbuf; /* Virtual address returned by memalign */
+	void *txbuf; /* Virtual address returned by memalign */
+	size_t rxtx_min_pages; /* Minimum number of pages in each of the RX/TX buffers */
+};
+
+struct ffa_partition_desc;
+
+/**
+ * struct ffa_partitions - descriptors for all secure partitions
+ * @count:	The number of partitions descriptors
+ * @descs	The partitions descriptors table
+ *
+ * Contains the partitions descriptors table
+ */
+struct ffa_partitions {
+	u32 count;
+	struct ffa_partition_desc *descs; /* Virtual address */
+};
+
+/**
+ * struct ffa_priv - the driver private data structure
+ *
+ * @fwk_version:	FF-A framework version
+ * @emul:	FF-A sandbox emulator
+ * @id:	u-boot endpoint ID
+ * @partitions:	The partitions descriptors structure
+ * @pair:	The RX/TX buffers pair
+ *
+ * The device private data structure containing all the
+ * data read from secure world.
+ */
+struct ffa_priv {
+	u32 fwk_version;
+	struct udevice *emul;
+	u16 id;
+	struct ffa_partitions partitions;
+	struct ffa_rxtxpair pair;
+};
+
+/**
+ * ffa_get_version_hdlr() - FFA_VERSION handler function
+ * @dev: The FF-A bus device
+ *
+ * Implement FFA_VERSION FF-A function
+ * to get from the secure world the FF-A framework version
+ * FFA_VERSION is used to discover the FF-A framework.
+ *
+ * Return:
+ *
+ * 0 on success. Otherwise, failure
+ */
+int ffa_get_version_hdlr(struct udevice *dev);
+
+/**
+ * invoke_ffa_fn() - SMC wrapper
+ * @args: FF-A ABI arguments to be copied to Xn registers
+ * @res: FF-A ABI return data to be copied from Xn registers
+ *
+ * Calls low level SMC implementation.
+ * This function should be implemented by the user driver.
+ */
+void invoke_ffa_fn(ffa_value_t args, ffa_value_t *res);
+
+#endif