[PATCH v7 3/6] firmware: smccc: Move RSI definitions to include/linux
From: Aneesh Kumar K.V (Arm)
Date: Thu Jun 11 2026 - 09:08:27 EST
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 RSI SMCCC definitions from arch/arm64/include/asm/ to
include/linux/ so they can be shared with the 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
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@xxxxxxxxxx>
---
arch/arm64/include/asm/rsi_cmds.h | 74 +---------------
.../virt/coco/arm-cca-guest/arm-cca-guest.c | 2 +
drivers/virt/coco/arm-cca-guest/rsi.h | 84 +++++++++++++++++++
.../linux/arm-smccc-rsi.h | 6 +-
4 files changed, 90 insertions(+), 76 deletions(-)
create mode 100644 drivers/virt/coco/arm-cca-guest/rsi.h
rename arch/arm64/include/asm/rsi_smc.h => include/linux/arm-smccc-rsi.h (98%)
diff --git a/arch/arm64/include/asm/rsi_cmds.h b/arch/arm64/include/asm/rsi_cmds.h
index 2c8763876dfb..633123a4e5d5 100644
--- a/arch/arm64/include/asm/rsi_cmds.h
+++ b/arch/arm64/include/asm/rsi_cmds.h
@@ -8,10 +8,9 @@
#include <linux/arm-smccc.h>
#include <linux/string.h>
+#include <linux/arm-smccc-rsi.h>
#include <asm/memory.h>
-#include <asm/rsi_smc.h>
-
#define RSI_GRANULE_SHIFT 12
#define RSI_GRANULE_SIZE (_AC(1, UL) << RSI_GRANULE_SHIFT)
@@ -88,75 +87,4 @@ static inline long rsi_set_addr_range_state(phys_addr_t start,
return res.a0;
}
-/**
- * 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)
-{
- struct arm_smccc_1_2_regs regs = { 0 };
-
- /* The challenge must be at least 32bytes and at most 64bytes */
- if (!challenge || size < 32 || size > 64)
- return -EINVAL;
-
- regs.a0 = SMC_RSI_ATTESTATION_TOKEN_INIT;
- memcpy(®s.a1, challenge, size);
- arm_smccc_1_2_smc(®s, ®s);
-
- if (regs.a0 == RSI_SUCCESS)
- return 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 /* __ASM_RSI_CMDS_H */
diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
index 66d00b6ceb78..8b6854e7a188 100644
--- a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
+++ b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c
@@ -14,6 +14,8 @@
#include <asm/rsi.h>
+#include "rsi.h"
+
/**
* struct arm_cca_token_info - a descriptor for the token buffer.
* @challenge: Pointer to the challenge data
diff --git a/drivers/virt/coco/arm-cca-guest/rsi.h b/drivers/virt/coco/arm-cca-guest/rsi.h
new file mode 100644
index 000000000000..f7303f4bce17
--- /dev/null
+++ b/drivers/virt/coco/arm-cca-guest/rsi.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2026 ARM Ltd.
+ */
+
+#ifndef _VIRT_COCO_RSI_H_
+#define _VIRT_COCO_RSI_H_
+
+#include <linux/arm-smccc-rsi.h>
+
+/**
+ * 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)
+{
+ struct arm_smccc_1_2_regs regs = { 0 };
+
+ /* The challenge must be at least 32bytes and at most 64bytes */
+ if (!challenge || size < 32 || size > 64)
+ return -EINVAL;
+
+ regs.a0 = SMC_RSI_ATTESTATION_TOKEN_INIT;
+ memcpy(®s.a1, challenge, size);
+ arm_smccc_1_2_smc(®s, ®s);
+
+ if (regs.a0 == RSI_SUCCESS)
+ return 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
diff --git a/arch/arm64/include/asm/rsi_smc.h b/include/linux/arm-smccc-rsi.h
similarity index 98%
rename from arch/arm64/include/asm/rsi_smc.h
rename to include/linux/arm-smccc-rsi.h
index e19253f96c94..fddb77986f70 100644
--- a/arch/arm64/include/asm/rsi_smc.h
+++ b/include/linux/arm-smccc-rsi.h
@@ -3,8 +3,8 @@
* Copyright (C) 2023 ARM Ltd.
*/
-#ifndef __ASM_RSI_SMC_H_
-#define __ASM_RSI_SMC_H_
+#ifndef __LINUX_ARM_SMCCC_RSI_H_
+#define __LINUX_ARM_SMCCC_RSI_H_
#include <linux/arm-smccc.h>
@@ -190,4 +190,4 @@ struct realm_config {
*/
#define SMC_RSI_HOST_CALL SMC_RSI_FID(0x199)
-#endif /* __ASM_RSI_SMC_H_ */
+#endif /* __LINUX_ARM_SMCCC_RSI_H_ */
--
2.43.0