[v5,04/13] riscv: sbi: add SBI FWFT extension calls

Commit Message

Clément Léger April 17, 2025, 12:19 p.m. UTC

Add FWFT extension calls. This will be ratified in SBI V3.0 hence, it is
provided as a separate commit that can be left out if needed.

Signed-off-by: Clément Léger <[e-mail]>
---
 arch/riscv/kernel/sbi.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

Patch

diff --git a/arch/riscv/kernel/sbi.c b/arch/riscv/kernel/sbi.c
index 379981c2bb21..7b062189b184 100644
--- a/arch/riscv/kernel/sbi.c
+++ b/arch/riscv/kernel/sbi.c
@@ -299,6 +299,8 @@  static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask,
 	return 0;
 }
 
+static bool sbi_fwft_supported;
+
 /**
  * sbi_fwft_set() - Set a feature on the local hart
  * @feature: The feature ID to be set
@@ -309,7 +311,15 @@  static int __sbi_rfence_v02(int fid, const struct cpumask *cpu_mask,
  */
 int sbi_fwft_set(u32 feature, unsigned long value, unsigned long flags)
 {
-	return -EOPNOTSUPP;
+	struct sbiret ret;
+
+	if (!sbi_fwft_supported)
+		return -EOPNOTSUPP;
+
+	ret = sbi_ecall(SBI_EXT_FWFT, SBI_EXT_FWFT_SET,
+			feature, value, flags, 0, 0, 0);
+
+	return sbi_err_map_linux_errno(ret.error);
 }
 
 struct fwft_set_req {
@@ -348,6 +358,9 @@  int sbi_fwft_local_set_cpumask(const cpumask_t *mask, u32 feature,
 		.error = ATOMIC_INIT(0),
 	};
 
+	if (!sbi_fwft_supported)
+		return -EOPNOTSUPP;
+
 	if (feature & SBI_FWFT_GLOBAL_FEATURE_BIT)
 		return -EINVAL;
 
@@ -679,6 +692,11 @@  void __init sbi_init(void)
 			pr_info("SBI DBCN extension detected\n");
 			sbi_debug_console_available = true;
 		}
+		if ((sbi_spec_version >= sbi_mk_version(3, 0)) &&
+		    (sbi_probe_extension(SBI_EXT_FWFT) > 0)) {
+			pr_info("SBI FWFT extension detected\n");
+			sbi_fwft_supported = true;
+		}
 	} else {
 		__sbi_set_timer = __sbi_set_timer_v01;
 		__sbi_send_ipi	= __sbi_send_ipi_v01;