arm64: insn: add encoders for atomic operations

It is a preparation patch for eBPF atomic supports under arm64. eBPF
needs support atomic[64]_fetch_add, atomic[64]_[fetch_]{and,or,xor} and
atomic[64]_{xchg|cmpxchg}. The ordering semantics of eBPF atomics are
the same with the implementations in linux kernel.

Add three helpers to support LDCLR/LDEOR/LDSET/SWP, CAS and DMB
instructions. STADD/STCLR/STEOR/STSET are simply encoded as aliases for
LDADD/LDCLR/LDEOR/LDSET with XZR as the destination register, so no extra
helper is added. atomic_fetch_add() and other atomic ops needs support for
STLXR instruction, so extend enum aarch64_insn_ldst_type to do that.

LDADD/LDEOR/LDSET/SWP and CAS instructions are only available when LSE
atomics is enabled, so just return AARCH64_BREAK_FAULT directly in
these newly-added helpers if CONFIG_ARM64_LSE_ATOMICS is disabled.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20220217072232.1186625-3-houtao1@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 73 insertions, 7 deletions

diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 6b776c8667b2..0b6b31307e68 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -205,7 +205,9 @@ enum aarch64_insn_ldst_type {
 	AARCH64_INSN_LDST_LOAD_PAIR_POST_INDEX,
 	AARCH64_INSN_LDST_STORE_PAIR_POST_INDEX,
 	AARCH64_INSN_LDST_LOAD_EX,
+	AARCH64_INSN_LDST_LOAD_ACQ_EX,
 	AARCH64_INSN_LDST_STORE_EX,
+	AARCH64_INSN_LDST_STORE_REL_EX,
 };
 
 enum aarch64_insn_adsb_type {
@@ -280,6 +282,36 @@ enum aarch64_insn_adr_type {
 	AARCH64_INSN_ADR_TYPE_ADR,
 };
 
+enum aarch64_insn_mem_atomic_op {
+	AARCH64_INSN_MEM_ATOMIC_ADD,
+	AARCH64_INSN_MEM_ATOMIC_CLR,
+	AARCH64_INSN_MEM_ATOMIC_EOR,
+	AARCH64_INSN_MEM_ATOMIC_SET,
+	AARCH64_INSN_MEM_ATOMIC_SWP,
+};
+
+enum aarch64_insn_mem_order_type {
+	AARCH64_INSN_MEM_ORDER_NONE,
+	AARCH64_INSN_MEM_ORDER_ACQ,
+	AARCH64_INSN_MEM_ORDER_REL,
+	AARCH64_INSN_MEM_ORDER_ACQREL,
+};
+
+enum aarch64_insn_mb_type {
+	AARCH64_INSN_MB_SY,
+	AARCH64_INSN_MB_ST,
+	AARCH64_INSN_MB_LD,
+	AARCH64_INSN_MB_ISH,
+	AARCH64_INSN_MB_ISHST,
+	AARCH64_INSN_MB_ISHLD,
+	AARCH64_INSN_MB_NSH,
+	AARCH64_INSN_MB_NSHST,
+	AARCH64_INSN_MB_NSHLD,
+	AARCH64_INSN_MB_OSH,
+	AARCH64_INSN_MB_OSHST,
+	AARCH64_INSN_MB_OSHLD,
+};
+
 #define	__AARCH64_INSN_FUNCS(abbr, mask, val)				\
 static __always_inline bool aarch64_insn_is_##abbr(u32 code)		\
 {									\
@@ -303,6 +335,11 @@ __AARCH64_INSN_FUNCS(store_post,	0x3FE00C00, 0x38000400)
 __AARCH64_INSN_FUNCS(load_post,	0x3FE00C00, 0x38400400)
 __AARCH64_INSN_FUNCS(str_reg,	0x3FE0EC00, 0x38206800)
 __AARCH64_INSN_FUNCS(ldadd,	0x3F20FC00, 0x38200000)
+__AARCH64_INSN_FUNCS(ldclr,	0x3F20FC00, 0x38201000)
+__AARCH64_INSN_FUNCS(ldeor,	0x3F20FC00, 0x38202000)
+__AARCH64_INSN_FUNCS(ldset,	0x3F20FC00, 0x38203000)
+__AARCH64_INSN_FUNCS(swp,	0x3F20FC00, 0x38208000)
+__AARCH64_INSN_FUNCS(cas,	0x3FA07C00, 0x08A07C00)
 __AARCH64_INSN_FUNCS(ldr_reg,	0x3FE0EC00, 0x38606800)
 __AARCH64_INSN_FUNCS(ldr_lit,	0xBF000000, 0x18000000)
 __AARCH64_INSN_FUNCS(ldrsw_lit,	0xFF000000, 0x98000000)
@@ -474,13 +511,6 @@ u32 aarch64_insn_gen_load_store_ex(enum aarch64_insn_register reg,
 				   enum aarch64_insn_register state,
 				   enum aarch64_insn_size_type size,
 				   enum aarch64_insn_ldst_type type);
-u32 aarch64_insn_gen_ldadd(enum aarch64_insn_register result,
-			   enum aarch64_insn_register address,
-			   enum aarch64_insn_register value,
-			   enum aarch64_insn_size_type size);
-u32 aarch64_insn_gen_stadd(enum aarch64_insn_register address,
-			   enum aarch64_insn_register value,
-			   enum aarch64_insn_size_type size);
 u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst,
 				 enum aarch64_insn_register src,
 				 int imm, enum aarch64_insn_variant variant,
@@ -541,6 +571,42 @@ u32 aarch64_insn_gen_prefetch(enum aarch64_insn_register base,
 			      enum aarch64_insn_prfm_type type,
 			      enum aarch64_insn_prfm_target target,
 			      enum aarch64_insn_prfm_policy policy);
+#ifdef CONFIG_ARM64_LSE_ATOMICS
+u32 aarch64_insn_gen_atomic_ld_op(enum aarch64_insn_register result,
+				  enum aarch64_insn_register address,
+				  enum aarch64_insn_register value,
+				  enum aarch64_insn_size_type size,
+				  enum aarch64_insn_mem_atomic_op op,
+				  enum aarch64_insn_mem_order_type order);
+u32 aarch64_insn_gen_cas(enum aarch64_insn_register result,
+			 enum aarch64_insn_register address,
+			 enum aarch64_insn_register value,
+			 enum aarch64_insn_size_type size,
+			 enum aarch64_insn_mem_order_type order);
+#else
+static inline
+u32 aarch64_insn_gen_atomic_ld_op(enum aarch64_insn_register result,
+				  enum aarch64_insn_register address,
+				  enum aarch64_insn_register value,
+				  enum aarch64_insn_size_type size,
+				  enum aarch64_insn_mem_atomic_op op,
+				  enum aarch64_insn_mem_order_type order)
+{
+	return AARCH64_BREAK_FAULT;
+}
+
+static inline
+u32 aarch64_insn_gen_cas(enum aarch64_insn_register result,
+			 enum aarch64_insn_register address,
+			 enum aarch64_insn_register value,
+			 enum aarch64_insn_size_type size,
+			 enum aarch64_insn_mem_order_type order)
+{
+	return AARCH64_BREAK_FAULT;
+}
+#endif
+u32 aarch64_insn_gen_dmb(enum aarch64_insn_mb_type type);
+
 s32 aarch64_get_branch_offset(u32 insn);
 u32 aarch64_set_branch_offset(u32 insn, s32 offset);