linux-kernel - [PATCH 10/10] RISC-V: Refactor bug and traps instructions

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Message-Id: <20230803-master-refactor-instructions-v4-v1-10-2128e61fa4ff@rivosinc.com>
Date:   Thu, 03 Aug 2023 19:10:35 -0700
From:   Charlie Jenkins <charlie@...osinc.com>
To:     linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org, kvm-riscv@...ts.infradead.org,
        bpf@...r.kernel.org
Cc:     Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        Peter Zijlstra <peterz@...radead.org>,
        Josh Poimboeuf <jpoimboe@...nel.org>,
        Jason Baron <jbaron@...mai.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ard Biesheuvel <ardb@...nel.org>,
        Anup Patel <anup@...infault.org>,
        Atish Patra <atishp@...shpatra.org>,
        Alexei Starovoitov <ast@...nel.org>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Martin KaFai Lau <martin.lau@...ux.dev>,
        Song Liu <song@...nel.org>, Yonghong Song <yhs@...com>,
        John Fastabend <john.fastabend@...il.com>,
        KP Singh <kpsingh@...nel.org>,
        Stanislav Fomichev <sdf@...gle.com>,
        Hao Luo <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>,
        Björn Töpel <bjorn@...nel.org>,
        Luke Nelson <luke.r.nels@...il.com>,
        Xi Wang <xi.wang@...il.com>, Nam Cao <namcaov@...il.com>,
        Charlie Jenkins <charlie@...osinc.com>
Subject: [PATCH 10/10] RISC-V: Refactor bug and traps instructions

Use shared instruction definitions in insn.h instead of manually
constructing them.

Signed-off-by: Charlie Jenkins <charlie@...osinc.com>
---
 arch/riscv/include/asm/bug.h | 18 +++++-------------
 arch/riscv/kernel/traps.c    |  9 +++++----
 2 files changed, 10 insertions(+), 17 deletions(-)

diff --git a/arch/riscv/include/asm/bug.h b/arch/riscv/include/asm/bug.h
index 1aaea81fb141..6d9002d93f85 100644
--- a/arch/riscv/include/asm/bug.h
+++ b/arch/riscv/include/asm/bug.h
@@ -11,21 +11,13 @@
 #include <linux/types.h>
 
 #include <asm/asm.h>
+#include <asm/insn.h>
 
-#define __INSN_LENGTH_MASK  _UL(0x3)
-#define __INSN_LENGTH_32    _UL(0x3)
-#define __COMPRESSED_INSN_MASK	_UL(0xffff)
+#define __IS_BUG_INSN_32(insn) riscv_insn_is_c_ebreak(insn)
+#define __IS_BUG_INSN_16(insn) riscv_insn_is_ebreak(insn)
 
-#define __BUG_INSN_32	_UL(0x00100073) /* ebreak */
-#define __BUG_INSN_16	_UL(0x9002) /* c.ebreak */
-
-#define GET_INSN_LENGTH(insn)						\
-({									\
-	unsigned long __len;						\
-	__len = ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32) ?	\
-		4UL : 2UL;						\
-	__len;								\
-})
+#define __BUG_INSN_32	RVG_MATCH_EBREAK
+#define __BUG_INSN_16	RVC_MATCH_C_EBREAK
 
 typedef u32 bug_insn_t;
 
diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c
index f910dfccbf5d..970b118d36b5 100644
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -22,6 +22,7 @@
 #include <asm/asm-prototypes.h>
 #include <asm/bug.h>
 #include <asm/csr.h>
+#include <asm/insn.h>
 #include <asm/processor.h>
 #include <asm/ptrace.h>
 #include <asm/syscall.h>
@@ -243,7 +244,7 @@ static inline unsigned long get_break_insn_length(unsigned long pc)
 	if (get_kernel_nofault(insn, (bug_insn_t *)pc))
 		return 0;
 
-	return GET_INSN_LENGTH(insn);
+	return INSN_LEN(insn);
 }
 
 void handle_break(struct pt_regs *regs)
@@ -389,10 +390,10 @@ int is_valid_bugaddr(unsigned long pc)
 		return 0;
 	if (get_kernel_nofault(insn, (bug_insn_t *)pc))
 		return 0;
-	if ((insn & __INSN_LENGTH_MASK) == __INSN_LENGTH_32)
-		return (insn == __BUG_INSN_32);
+	if (INSN_IS_C(insn))
+		return __IS_BUG_INSN_16(insn);
 	else
-		return ((insn & __COMPRESSED_INSN_MASK) == __BUG_INSN_16);
+		return __IS_BUG_INSN_32(insn);
 }
 #endif /* CONFIG_GENERIC_BUG */
 

-- 
2.34.1