[PATCH v5 01/13] riscv: sbi: add Firmware Feature (FWFT) SBI extensions definitions

Clément Léger
2025-04-17T12:36:11Z

The Firmware Features extension (FWFT) was added as part of the SBI 3.0
specification. Add SBI definitions to use this extension.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Deepak Gupta <debug@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
---
arch/riscv/include/asm/sbi.h | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)

diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 3d250824178b..bb077d0c912f 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -35,6 +35,7 @@ enum sbi_ext_id {
SBI_EXT_DBCN = 0x4442434E,
SBI_EXT_STA = 0x535441,
SBI_EXT_NACL = 0x4E41434C,
+ SBI_EXT_FWFT = 0x46574654,

/* Experimentals extensions must lie within this range */
SBI_EXT_EXPERIMENTAL_START = 0x08000000,
@@ -402,6 +403,33 @@ enum sbi_ext_nacl_feature {
#define SBI_NACL_SHMEM_SRET_X(__i) ((__riscv_xlen / 8) * (__i))
#define SBI_NACL_SHMEM_SRET_X_LAST 31

+/* SBI function IDs for FW feature extension */
+#define SBI_EXT_FWFT_SET 0x0
+#define SBI_EXT_FWFT_GET 0x1
+
+enum sbi_fwft_feature_t {
+ SBI_FWFT_MISALIGNED_EXC_DELEG = 0x0,
+ SBI_FWFT_LANDING_PAD = 0x1,
+ SBI_FWFT_SHADOW_STACK = 0x2,
+ SBI_FWFT_DOUBLE_TRAP = 0x3,
+ SBI_FWFT_PTE_AD_HW_UPDATING = 0x4,
+ SBI_FWFT_POINTER_MASKING_PMLEN = 0x5,
+ SBI_FWFT_LOCAL_RESERVED_START = 0x6,
+ SBI_FWFT_LOCAL_RESERVED_END = 0x3fffffff,
+ SBI_FWFT_LOCAL_PLATFORM_START = 0x40000000,
+ SBI_FWFT_LOCAL_PLATFORM_END = 0x7fffffff,
+
+ SBI_FWFT_GLOBAL_RESERVED_START = 0x80000000,
+ SBI_FWFT_GLOBAL_RESERVED_END = 0xbfffffff,
+ SBI_FWFT_GLOBAL_PLATFORM_START = 0xc0000000,
+ SBI_FWFT_GLOBAL_PLATFORM_END = 0xffffffff,
+};
+
+#define SBI_FWFT_PLATFORM_FEATURE_BIT BIT(30)
+#define SBI_FWFT_GLOBAL_FEATURE_BIT BIT(31)
+
+#define SBI_FWFT_SET_FLAG_LOCK BIT(0)
+
/* SBI spec version fields */
#define SBI_SPEC_VERSION_DEFAULT 0x1
#define SBI_SPEC_VERSION_MAJOR_SHIFT 24
@@ -419,6 +447,11 @@ enum sbi_ext_nacl_feature {
#define SBI_ERR_ALREADY_STARTED -7
#define SBI_ERR_ALREADY_STOPPED -8
#define SBI_ERR_NO_SHMEM -9
+#define SBI_ERR_INVALID_STATE -10
+#define SBI_ERR_BAD_RANGE -11
+#define SBI_ERR_TIMEOUT -12
+#define SBI_ERR_IO -13
+#define SBI_ERR_DENIED_LOCKED -14

extern unsigned long sbi_spec_version;
struct sbiret {