[PATCH] lib: sbi_misaligned_ldst: Add handling of C.LHU/C.LH and C.SH

Nylon Chen nylon.chen at sifive.com
Sun Feb 25 21:56:44 PST 2024


From: "Nylon Chen" <nylon.chen at sifive.com>

Added exception handling for compressed instructions C.LHU, C.LH, and
C.SH from the zcb extension to the sbi_misaligned_ldst library.

Signed-off-by: Nylon Chen <nylon.chen at sifive.com>
---
 include/sbi/riscv_encoding.h  |  7 +++++++
 lib/sbi/sbi_misaligned_ldst.c | 10 ++++++++++
 2 files changed, 17 insertions(+)

diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h
index e74cc0d..3d77e26 100644
--- a/include/sbi/riscv_encoding.h
+++ b/include/sbi/riscv_encoding.h
@@ -837,6 +837,13 @@
 #define INSN_MATCH_C_FSWSP		0xe002
 #define INSN_MASK_C_FSWSP		0xe003
 
+#define INSN_MATCH_C_LHU		0x8400
+#define INSN_MASK_C_LHU		0xfc43
+#define INSN_MATCH_C_LH		0x8440
+#define INSN_MASK_C_LH			0xfc43
+#define INSN_MATCH_C_SH		0x8c00
+#define INSN_MASK_C_SH			0xfc43
+
 #define INSN_MASK_WFI			0xffffff00
 #define INSN_MATCH_WFI			0x10500000
 
diff --git a/lib/sbi/sbi_misaligned_ldst.c b/lib/sbi/sbi_misaligned_ldst.c
index aa512de..9ca225a 100644
--- a/lib/sbi/sbi_misaligned_ldst.c
+++ b/lib/sbi/sbi_misaligned_ldst.c
@@ -123,6 +123,13 @@ int sbi_misaligned_load_handler(ulong addr, ulong tval2, ulong tinst,
 		len = 4;
 #endif
 #endif
+	} else if ((insn & INSN_MASK_C_LHU) == INSN_MATCH_C_LHU) {
+		len = 2;
+		insn = RVC_RS2S(insn) << SH_RD;
+	} else if ((insn & INSN_MASK_C_LH) == INSN_MATCH_C_LH) {
+		len = 2;
+		shift = 8 * (sizeof(ulong) - len);
+		insn = RVC_RS2S(insn) << SH_RD;
 	} else {
 		uptrap.epc = regs->mepc;
 		uptrap.cause = CAUSE_MISALIGNED_LOAD;
@@ -237,6 +244,9 @@ int sbi_misaligned_store_handler(ulong addr, ulong tval2, ulong tinst,
 		val.data_ulong = GET_F32_RS2C(insn, regs);
 #endif
 #endif
+	} else if ((insn & INSN_MASK_C_SH) == INSN_MATCH_C_SH) {
+		len		= 2;
+		val.data_ulong = GET_RS2S(insn, regs);
 	} else {
 		uptrap.epc = regs->mepc;
 		uptrap.cause = CAUSE_MISALIGNED_STORE;
-- 
2.34.1




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