firmware: arm_rmm: Move RSI support out of arch/arm64

The RSI SMCCC function IDs describe a firmware ABI and are not arm64
architecture specific definitions. Follow-up changes need to use them from
non-arch code, including drivers/firmware/smccc and the Arm CCA guest
driver.

Move the complete Realm Service Interface (RSI) implementation from
arch/arm64 to drivers/firmware/arm_rmm. The RSI SMCCC definitions and
command helpers are also moved to include/linux so they can be shared by
architecture code and firmware or driver code. This also keeps the
firmware interface outside architecture code, as requested [1].

[1] https://lore.kernel.org/all/agsNO9cc7H-b0H8L@willie-the-truck

Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

2 files changed, 433 insertions, 0 deletions

diff --git a/include/linux/arm-rsi-cmds.h b/include/linux/arm-rsi-cmds.h
new file mode 100644
index 000000000000..9e8a8c189ca1
--- /dev/null
+++ b/include/linux/arm-rsi-cmds.h
@@ -0,0 +1,240 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#ifndef __LINUX_ARM_RSI_CMDS_H_
+#define __LINUX_ARM_RSI_CMDS_H_
+
+#include <linux/arm-smccc-rsi.h>
+#include <linux/jump_label.h>
+#include <linux/string.h>
+#include <asm/memory.h>
+
+#define RSI_PDEV_NAME "arm-cca-dev"
+#ifdef CONFIG_ARM_RMM_RSI
+DECLARE_STATIC_KEY_FALSE(rsi_present);
+
+void __init arm64_rsi_init(void);
+
+bool arm64_rsi_is_protected(phys_addr_t base, size_t size);
+
+static inline bool is_realm_world(void)
+{
+	return static_branch_unlikely(&rsi_present);
+}
+#else
+static inline void arm64_rsi_init(void) { }
+
+static inline bool arm64_rsi_is_protected(phys_addr_t base, size_t size)
+{
+	return false;
+}
+
+static inline bool is_realm_world(void) { return false; }
+#endif
+
+#define RSI_GRANULE_SHIFT		12
+#define RSI_GRANULE_SIZE		(_AC(1, UL) << RSI_GRANULE_SHIFT)
+
+enum ripas {
+	RSI_RIPAS_EMPTY = 0,
+	RSI_RIPAS_RAM = 1,
+	RSI_RIPAS_DESTROYED = 2,
+	RSI_RIPAS_DEV = 3,
+};
+
+static inline unsigned long rsi_request_version(unsigned long req,
+						unsigned long *out_lower,
+						unsigned long *out_higher)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(SMC_RSI_ABI_VERSION, req, 0, 0, 0, 0, 0, 0, &res);
+
+	if (out_lower)
+		*out_lower = res.a1;
+	if (out_higher)
+		*out_higher = res.a2;
+
+	return res.a0;
+}
+
+static inline unsigned long rsi_get_realm_config(struct realm_config *cfg)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(SMC_RSI_REALM_CONFIG, virt_to_phys(cfg),
+		      0, 0, 0, 0, 0, 0, &res);
+	return res.a0;
+}
+
+static inline unsigned long rsi_ipa_state_get(phys_addr_t start,
+					      phys_addr_t end,
+					      enum ripas *state,
+					      phys_addr_t *top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(SMC_RSI_IPA_STATE_GET,
+		      start, end, 0, 0, 0, 0, 0,
+		      &res);
+
+	if (res.a0 == RSI_SUCCESS) {
+		if (top)
+			*top = res.a1;
+		if (state)
+			*state = res.a2;
+	}
+
+	return res.a0;
+}
+
+static inline long rsi_set_addr_range_state(phys_addr_t start,
+					    phys_addr_t end,
+					    enum ripas state,
+					    unsigned long flags,
+					    phys_addr_t *top)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_smc(SMC_RSI_IPA_STATE_SET, start, end, state,
+		      flags, 0, 0, 0, &res);
+
+	if (top)
+		*top = res.a1;
+
+	if (res.a2 != RSI_ACCEPT)
+		return -EPERM;
+
+	return res.a0;
+}
+
+static inline int rsi_set_memory_range(phys_addr_t start, phys_addr_t end,
+				       enum ripas state, unsigned long flags)
+{
+	unsigned long ret;
+	phys_addr_t top;
+
+	while (start != end) {
+		ret = rsi_set_addr_range_state(start, end, state, flags, &top);
+		if (ret || top < start || top > end)
+			return -EINVAL;
+		start = top;
+	}
+
+	return 0;
+}
+
+/*
+ * Convert the specified range to RAM. Do not use this if you rely on the
+ * contents of a page that may already be in RAM state.
+ */
+static inline int rsi_set_memory_range_protected(phys_addr_t start,
+						 phys_addr_t end)
+{
+	return rsi_set_memory_range(start, end, RSI_RIPAS_RAM,
+				    RSI_CHANGE_DESTROYED);
+}
+
+/*
+ * Convert the specified range to RAM. Do not convert any pages that may have
+ * been DESTROYED, without our permission.
+ */
+static inline int rsi_set_memory_range_protected_safe(phys_addr_t start,
+						      phys_addr_t end)
+{
+	return rsi_set_memory_range(start, end, RSI_RIPAS_RAM,
+				    RSI_NO_CHANGE_DESTROYED);
+}
+
+static inline int rsi_set_memory_range_shared(phys_addr_t start,
+					      phys_addr_t end)
+{
+	return rsi_set_memory_range(start, end, RSI_RIPAS_EMPTY,
+				    RSI_CHANGE_DESTROYED);
+}
+
+#define RSI_ATTEST_CHALLENGE_MIN_SIZE	32
+#define RSI_ATTEST_CHALLENGE_MAX_SIZE	64
+
+struct rsi_attestation_token_init_args {
+	unsigned long fid;
+	u8 challenge[RSI_ATTEST_CHALLENGE_MAX_SIZE];
+};
+
+/**
+ * rsi_attestation_token_init - Initialise the operation to retrieve an
+ * attestation token.
+ *
+ * @challenge:	The challenge data to be used in the attestation token
+ *		generation.
+ * @size:	Size of the challenge data in bytes.
+ *
+ * Initialises the attestation token generation and returns an upper bound
+ * on the attestation token size that can be used to allocate an adequate
+ * buffer. The caller is expected to subsequently call
+ * rsi_attestation_token_continue() to retrieve the attestation token data on
+ * the same CPU.
+ *
+ * Returns:
+ *  On success, returns the upper limit of the attestation report size.
+ *  Otherwise, -EINVAL
+ */
+static inline long
+rsi_attestation_token_init(const u8 *challenge, unsigned long size)
+{
+	union {
+		struct arm_smccc_1_2_regs regs;
+		struct rsi_attestation_token_init_args init;
+	} args = { 0 };
+
+	if (!challenge || size < RSI_ATTEST_CHALLENGE_MIN_SIZE ||
+	    size > RSI_ATTEST_CHALLENGE_MAX_SIZE)
+		return -EINVAL;
+
+	args.init.fid = SMC_RSI_ATTESTATION_TOKEN_INIT;
+	memcpy(args.init.challenge, challenge, size);
+	arm_smccc_1_2_smc(&args.regs, &args.regs);
+
+	if (args.regs.a0 == RSI_SUCCESS)
+		return args.regs.a1;
+
+	return -EINVAL;
+}
+
+/**
+ * rsi_attestation_token_continue - Continue the operation to retrieve an
+ * attestation token.
+ *
+ * @granule: {I}PA of the Granule to which the token will be written.
+ * @offset:  Offset within Granule to start of buffer in bytes.
+ * @size:    The size of the buffer.
+ * @len:     The number of bytes written to the buffer.
+ *
+ * Retrieves up to a RSI_GRANULE_SIZE worth of token data per call. The caller
+ * is expected to call rsi_attestation_token_init() before calling this
+ * function to retrieve the attestation token.
+ *
+ * Return:
+ * * %RSI_SUCCESS     - Attestation token retrieved successfully.
+ * * %RSI_INCOMPLETE  - Token generation is not complete.
+ * * %RSI_ERROR_INPUT - A parameter was not valid.
+ * * %RSI_ERROR_STATE - Attestation not in progress.
+ */
+static inline unsigned long rsi_attestation_token_continue(phys_addr_t granule,
+							   unsigned long offset,
+							   unsigned long size,
+							   unsigned long *len)
+{
+	struct arm_smccc_res res;
+
+	arm_smccc_1_1_invoke(SMC_RSI_ATTESTATION_TOKEN_CONTINUE,
+			     granule, offset, size, 0, &res);
+
+	if (len)
+		*len = res.a1;
+	return res.a0;
+}
+
+#endif /* __LINUX_ARM_RSI_CMDS_H_ */
diff --git a/include/linux/arm-smccc-rsi.h b/include/linux/arm-smccc-rsi.h
new file mode 100644
index 000000000000..fddb77986f70
--- /dev/null
+++ b/include/linux/arm-smccc-rsi.h
@@ -0,0 +1,193 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023 ARM Ltd.
+ */
+
+#ifndef __LINUX_ARM_SMCCC_RSI_H_
+#define __LINUX_ARM_SMCCC_RSI_H_
+
+#include <linux/arm-smccc.h>
+
+/*
+ * This file describes the Realm Services Interface (RSI) Application Binary
+ * Interface (ABI) for SMC calls made from within the Realm to the RMM and
+ * serviced by the RMM.
+ */
+
+/*
+ * The major version number of the RSI implementation.  This is increased when
+ * the binary format or semantics of the SMC calls change.
+ */
+#define RSI_ABI_VERSION_MAJOR		UL(1)
+
+/*
+ * The minor version number of the RSI implementation.  This is increased when
+ * a bug is fixed, or a feature is added without breaking binary compatibility.
+ */
+#define RSI_ABI_VERSION_MINOR		UL(0)
+
+#define RSI_ABI_VERSION			((RSI_ABI_VERSION_MAJOR << 16) | \
+					 RSI_ABI_VERSION_MINOR)
+
+#define RSI_ABI_VERSION_GET_MAJOR(_version) ((_version) >> 16)
+#define RSI_ABI_VERSION_GET_MINOR(_version) ((_version) & 0xFFFF)
+
+#define RSI_SUCCESS		UL(0)
+#define RSI_ERROR_INPUT		UL(1)
+#define RSI_ERROR_STATE		UL(2)
+#define RSI_INCOMPLETE		UL(3)
+#define RSI_ERROR_UNKNOWN	UL(4)
+
+#define SMC_RSI_FID(n)		ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,      \
+						   ARM_SMCCC_SMC_64,         \
+						   ARM_SMCCC_OWNER_STANDARD, \
+						   n)
+
+/*
+ * Returns RSI version.
+ *
+ * arg1 == Requested interface revision
+ * ret0 == Status / error
+ * ret1 == Lower implemented interface revision
+ * ret2 == Higher implemented interface revision
+ */
+#define SMC_RSI_ABI_VERSION	SMC_RSI_FID(0x190)
+
+/*
+ * Read feature register.
+ *
+ * arg1 == Feature register index
+ * ret0 == Status / error
+ * ret1 == Feature register value
+ */
+#define SMC_RSI_FEATURES			SMC_RSI_FID(0x191)
+
+/*
+ * Read measurement for the current Realm.
+ *
+ * arg1 == Index, which measurements slot to read
+ * ret0 == Status / error
+ * ret1 == Measurement value, bytes:  0 -  7
+ * ret2 == Measurement value, bytes:  8 - 15
+ * ret3 == Measurement value, bytes: 16 - 23
+ * ret4 == Measurement value, bytes: 24 - 31
+ * ret5 == Measurement value, bytes: 32 - 39
+ * ret6 == Measurement value, bytes: 40 - 47
+ * ret7 == Measurement value, bytes: 48 - 55
+ * ret8 == Measurement value, bytes: 56 - 63
+ */
+#define SMC_RSI_MEASUREMENT_READ		SMC_RSI_FID(0x192)
+
+/*
+ * Extend Realm Extensible Measurement (REM) value.
+ *
+ * arg1  == Index, which measurements slot to extend
+ * arg2  == Size of realm measurement in bytes, max 64 bytes
+ * arg3  == Measurement value, bytes:  0 -  7
+ * arg4  == Measurement value, bytes:  8 - 15
+ * arg5  == Measurement value, bytes: 16 - 23
+ * arg6  == Measurement value, bytes: 24 - 31
+ * arg7  == Measurement value, bytes: 32 - 39
+ * arg8  == Measurement value, bytes: 40 - 47
+ * arg9  == Measurement value, bytes: 48 - 55
+ * arg10 == Measurement value, bytes: 56 - 63
+ * ret0  == Status / error
+ */
+#define SMC_RSI_MEASUREMENT_EXTEND		SMC_RSI_FID(0x193)
+
+/*
+ * Initialize the operation to retrieve an attestation token.
+ *
+ * arg1 == Challenge value, bytes:  0 -  7
+ * arg2 == Challenge value, bytes:  8 - 15
+ * arg3 == Challenge value, bytes: 16 - 23
+ * arg4 == Challenge value, bytes: 24 - 31
+ * arg5 == Challenge value, bytes: 32 - 39
+ * arg6 == Challenge value, bytes: 40 - 47
+ * arg7 == Challenge value, bytes: 48 - 55
+ * arg8 == Challenge value, bytes: 56 - 63
+ * ret0 == Status / error
+ * ret1 == Upper bound of token size in bytes
+ */
+#define SMC_RSI_ATTESTATION_TOKEN_INIT		SMC_RSI_FID(0x194)
+
+/*
+ * Continue the operation to retrieve an attestation token.
+ *
+ * arg1 == The IPA of token buffer
+ * arg2 == Offset within the granule of the token buffer
+ * arg3 == Size of the granule buffer
+ * ret0 == Status / error
+ * ret1 == Length of token bytes copied to the granule buffer
+ */
+#define SMC_RSI_ATTESTATION_TOKEN_CONTINUE	SMC_RSI_FID(0x195)
+
+#ifndef __ASSEMBLER__
+
+struct realm_config {
+	union {
+		struct {
+			unsigned long ipa_bits; /* Width of IPA in bits */
+			unsigned long hash_algo; /* Hash algorithm */
+		};
+		u8 pad[0x200];
+	};
+	union {
+		u8 rpv[64]; /* Realm Personalization Value */
+		u8 pad2[0xe00];
+	};
+	/*
+	 * The RMM requires the configuration structure to be aligned to a 4k
+	 * boundary, ensure this happens by aligning this structure.
+	 */
+} __aligned(0x1000);
+
+#endif /* __ASSEMBLER__ */
+
+/*
+ * Read configuration for the current Realm.
+ *
+ * arg1 == struct realm_config addr
+ * ret0 == Status / error
+ */
+#define SMC_RSI_REALM_CONFIG			SMC_RSI_FID(0x196)
+
+/*
+ * Request RIPAS of a target IPA range to be changed to a specified value.
+ *
+ * arg1 == Base IPA address of target region
+ * arg2 == Top of the region
+ * arg3 == RIPAS value
+ * arg4 == flags
+ * ret0 == Status / error
+ * ret1 == Top of modified IPA range
+ * ret2 == Whether the Host accepted or rejected the request
+ */
+#define SMC_RSI_IPA_STATE_SET			SMC_RSI_FID(0x197)
+
+#define RSI_NO_CHANGE_DESTROYED			UL(0)
+#define RSI_CHANGE_DESTROYED			UL(1)
+
+#define RSI_ACCEPT				UL(0)
+#define RSI_REJECT				UL(1)
+
+/*
+ * Get RIPAS of a target IPA range.
+ *
+ * arg1 == Base IPA of target region
+ * arg2 == End of target IPA region
+ * ret0 == Status / error
+ * ret1 == Top of IPA region which has the reported RIPAS value
+ * ret2 == RIPAS value
+ */
+#define SMC_RSI_IPA_STATE_GET			SMC_RSI_FID(0x198)
+
+/*
+ * Make a Host call.
+ *
+ * arg1 == IPA of host call structure
+ * ret0 == Status / error
+ */
+#define SMC_RSI_HOST_CALL			SMC_RSI_FID(0x199)
+
+#endif /* __LINUX_ARM_SMCCC_RSI_H_ */