6.12-stable review patch. If anyone has any objections, please let me know.
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From: Nylon Chen nylon.chen@sifive.com
[ Upstream commit eb16b3727c05ed36420c90eca1e8f0e279514c1c ]
Add support for the Zcb extension's compressed half-word instructions (C.LHU, C.LH, and C.SH) in the RISC-V misaligned access trap handler.
Signed-off-by: Zong Li zong.li@sifive.com Signed-off-by: Nylon Chen nylon.chen@sifive.com Fixes: 956d705dd279 ("riscv: Unaligned load/store handling for M_MODE") Reviewed-by: Alexandre Ghiti alexghiti@rivosinc.com Link: https://lore.kernel.org/r/20250411073850.3699180-2-nylon.chen@sifive.com Signed-off-by: Alexandre Ghiti alexghiti@rivosinc.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kernel/traps_misaligned.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/arch/riscv/kernel/traps_misaligned.c b/arch/riscv/kernel/traps_misaligned.c index 9a80a12f6b48f..d14bfc23e315b 100644 --- a/arch/riscv/kernel/traps_misaligned.c +++ b/arch/riscv/kernel/traps_misaligned.c @@ -87,6 +87,13 @@ #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_LEN(insn) ((((insn) & 0x3) < 0x3) ? 2 : 4)
#if defined(CONFIG_64BIT) @@ -405,6 +412,13 @@ int handle_misaligned_load(struct pt_regs *regs) fp = 1; len = 4; #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 { regs->epc = epc; return -1; @@ -504,6 +518,9 @@ int handle_misaligned_store(struct pt_regs *regs) len = 4; val.data_ulong = GET_F32_RS2C(insn, regs); #endif + } else if ((insn & INSN_MASK_C_SH) == INSN_MATCH_C_SH) { + len = 2; + val.data_ulong = GET_RS2S(insn, regs); } else { regs->epc = epc; return -1;