firmware: smccc: Add SMCCC TRNG function call IDs

The ARM architected TRNG firmware interface, described in ARM spec
DEN0098, define an ARM SMCCC based interface to a true random number
generator, provided by firmware.

Add the definitions of the SMCCC functions as defined by the spec.

Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Andre Przywara <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>
Reviewed-by: Sudeep Holla <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index f860645f6512833c602aea5f277e896a0cf9a442..62c54234576c4ab3e7c5dc13495e0f3a6d905adc 100644 (file)
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -102,6 +102,37 @@
                           ARM_SMCCC_OWNER_STANDARD_HYP,        \
                           0x21)
 
+/* TRNG entropy source calls (defined by ARM DEN0098) */
+#define ARM_SMCCC_TRNG_VERSION                                 \
+       ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                 \
+                          ARM_SMCCC_SMC_32,                    \
+                          ARM_SMCCC_OWNER_STANDARD,            \
+                          0x50)
+
+#define ARM_SMCCC_TRNG_FEATURES                                        \
+       ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                 \
+                          ARM_SMCCC_SMC_32,                    \
+                          ARM_SMCCC_OWNER_STANDARD,            \
+                          0x51)
+
+#define ARM_SMCCC_TRNG_GET_UUID                                        \
+       ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                 \
+                          ARM_SMCCC_SMC_32,                    \
+                          ARM_SMCCC_OWNER_STANDARD,            \
+                          0x52)
+
+#define ARM_SMCCC_TRNG_RND32                                   \
+       ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                 \
+                          ARM_SMCCC_SMC_32,                    \
+                          ARM_SMCCC_OWNER_STANDARD,            \
+                          0x53)
+
+#define ARM_SMCCC_TRNG_RND64                                   \
+       ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,                 \
+                          ARM_SMCCC_SMC_64,                    \
+                          ARM_SMCCC_OWNER_STANDARD,            \
+                          0x53)
+
 /*
  * Return codes defined in ARM DEN 0070A
  * ARM DEN 0070A is now merged/consolidated into ARM DEN 0028 C