On 10/5/24 12:42 AM, Steven Price wrote:
From: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
The RMM (Realm Management Monitor) provides functionality that can be
accessed by a realm guest through SMC (Realm Services Interface) calls.
The SMC definitions are based on DEN0137[1] version 1.0-rel0.
[1] https://developer.arm.com/documentation/den0137/1-0rel0/
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Reviewed-by: Gavin Shan <gshan@xxxxxxxxx>
Signed-off-by: Steven Price <steven.price@xxxxxxx>
---
[...]
+
+static inline unsigned 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;
+}
+
Similar to rsi_attestation_token_init(), the return value type needs to be 'long'
since '-EPERM' can be returned from the function.
+/**
+ * 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 int 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;
+}
+
The return value type of this function needs to be 'unsigned long' even it's
converted to 'int' in arm_cca_attestation_continue(). In this way, the wrapper
functions has consistent return value type, which is 'unsigned long' or 'long'.
Thanks,
Gavin
