[kvm-unit-tests PATCH v11 4/8] lib: riscv: Add functions for version checking

[Clément Léger]

Version checking was done using some custom hardcoded values, backport a
few SBI function and defines from Linux to do that cleanly.

Signed-off-by: Clément Léger <cleger at rivosinc.com>
---
 lib/riscv/asm/sbi.h | 15 +++++++++++++++
 lib/riscv/sbi.c     |  9 +++++++--
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/lib/riscv/asm/sbi.h b/lib/riscv/asm/sbi.h
index 2f4d91ef..ee9d6e50 100644
--- a/lib/riscv/asm/sbi.h
+++ b/lib/riscv/asm/sbi.h
@@ -18,6 +18,13 @@
 #define SBI_ERR_IO			-13
 #define SBI_ERR_DENIED_LOCKED		-14
 
+/* SBI spec version fields */
+#define SBI_SPEC_VERSION_MAJOR_SHIFT	24
+#define SBI_SPEC_VERSION_MAJOR_MASK	0x7f
+#define SBI_SPEC_VERSION_MINOR_MASK	0xffffff
+#define SBI_SPEC_VERSION_MASK		((SBI_SPEC_VERSION_MAJOR_MASK << SBI_SPEC_VERSION_MAJOR_SHIFT) | \
+					SBI_SPEC_VERSION_MINOR_MASK)
+
 #ifndef __ASSEMBLER__
 #include <cpumask.h>
 
@@ -110,6 +117,13 @@ struct sbiret {
 	long value;
 };
 
+/* Make SBI version */
+static inline unsigned long sbi_mk_version(unsigned long major, unsigned long minor)
+{
+	return ((major & SBI_SPEC_VERSION_MAJOR_MASK) << SBI_SPEC_VERSION_MAJOR_SHIFT)
+		| (minor & SBI_SPEC_VERSION_MINOR_MASK);
+}
+
 struct sbiret sbi_ecall(int ext, int fid, unsigned long arg0,
 			unsigned long arg1, unsigned long arg2,
 			unsigned long arg3, unsigned long arg4,
@@ -124,6 +138,7 @@ struct sbiret sbi_send_ipi_cpu(int cpu);
 struct sbiret sbi_send_ipi_cpumask(const cpumask_t *mask);
 struct sbiret sbi_send_ipi_broadcast(void);
 struct sbiret sbi_set_timer(unsigned long stime_value);
+struct sbiret sbi_get_spec_version(void);
 long sbi_probe(int ext);
 
 #endif /* !__ASSEMBLER__ */
diff --git a/lib/riscv/sbi.c b/lib/riscv/sbi.c
index 02dd338c..9d4eb541 100644
--- a/lib/riscv/sbi.c
+++ b/lib/riscv/sbi.c
@@ -107,12 +107,17 @@ struct sbiret sbi_set_timer(unsigned long stime_value)
 	return sbi_ecall(SBI_EXT_TIME, SBI_EXT_TIME_SET_TIMER, stime_value, 0, 0, 0, 0, 0);
 }
 
+struct sbiret sbi_get_spec_version(void)
+{
+	return sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0, 0, 0, 0, 0, 0);
+}
+
 long sbi_probe(int ext)
 {
 	struct sbiret ret;
 
-	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_GET_SPEC_VERSION, 0, 0, 0, 0, 0, 0);
-	assert(!ret.error && (ret.value & 0x7ffffffful) >= 2);
+	ret = sbi_get_spec_version();
+	assert(!ret.error && (ret.value & SBI_SPEC_VERSION_MASK) >= sbi_mk_version(0, 2));
 
 	ret = sbi_ecall(SBI_EXT_BASE, SBI_EXT_BASE_PROBE_EXT, ext, 0, 0, 0, 0, 0);
 	assert(!ret.error);
-- 
2.47.2