// SPDX-License-Identifier: GPL-2.0 #include <linux/kernel.h>#include <linux/jump_label.h> #include "asm/cacheflush.h" #define JUMPLABEL_ERR	"ARC: jump_label: ERROR: " /* Halt system on fatal error to make debug easier */#define arc_jl_fatal(format...)						\({									\	pr_err(JUMPLABEL_ERR format);					\	BUG();								\}) static inline u32 arc_gen_nop(void){	/* 1x 32bit NOP in middle endian */	return 0x7000264a;} /* * Atomic update of patched instruction is only available if this * instruction doesn't cross L1 cache line boundary. You can read about * the way we achieve this in arc/include/asm/jump_label.h */static inline void instruction_align_assert(void *addr, int len){	unsigned long a = (unsigned long)addr; 	if ((a >> L1_CACHE_SHIFT) != ((a + len - 1) >> L1_CACHE_SHIFT))		arc_jl_fatal("instruction (addr %px) cross L1 cache line border",			     addr);} /* * ARCv2 'Branch unconditionally' instruction: * 00000ssssssssss1SSSSSSSSSSNRtttt * s S[n:0] lower bits signed immediate (number is bitfield size) * S S[m:n+1] upper bits signed immediate (number is bitfield size) * t S[24:21] upper bits signed immediate (branch unconditionally far) * N N <.d> delay slot mode * R R Reserved */static inline u32 arc_gen_branch(jump_label_t pc, jump_label_t target){	u32 instruction_l, instruction_r;	u32 pcl = pc & GENMASK(31, 2);	u32 u_offset = target - pcl;	u32 s, S, t; 	/*	 * Offset in 32-bit branch instruction must to fit into s25.	 * Something is terribly broken if we get such huge offset within one	 * function.	 */	if ((s32)u_offset < -16777216 || (s32)u_offset > 16777214)		arc_jl_fatal("gen branch with offset (%d) not fit in s25",			     (s32)u_offset); 	/*	 * All instructions are aligned by 2 bytes so we should never get offset	 * here which is not 2 bytes aligned.	 */	if (u_offset & 0x1)		arc_jl_fatal("gen branch with offset (%d) unaligned to 2 bytes",			     (s32)u_offset); 	s = (u_offset >> 1)  & GENMASK(9, 0);	S = (u_offset >> 11) & GENMASK(9, 0);	t = (u_offset >> 21) & GENMASK(3, 0); 	/* 00000ssssssssss1 */	instruction_l = (s << 1) | 0x1;	/* SSSSSSSSSSNRtttt */	instruction_r = (S << 6) | t; 	return (instruction_r << 16) | (instruction_l & GENMASK(15, 0));} void arch_jump_label_transform(struct jump_entry *entry,			       enum jump_label_type type){	jump_label_t *instr_addr = (jump_label_t *)entry->code;	u32 instr; 	instruction_align_assert(instr_addr, JUMP_LABEL_NOP_SIZE); 	if (type == JUMP_LABEL_JMP)		instr = arc_gen_branch(entry->code, entry->target);	else		instr = arc_gen_nop(); 	WRITE_ONCE(*instr_addr, instr);	flush_icache_range(entry->code, entry->code + JUMP_LABEL_NOP_SIZE);} #ifdef CONFIG_ARC_DBG_JUMP_LABEL#define SELFTEST_MSG	"ARC: instruction generation self-test: " struct arc_gen_branch_testdata {	jump_label_t pc;	jump_label_t target_address;	u32 expected_instr;}; static __init int branch_gen_test(const struct arc_gen_branch_testdata *test){	u32 instr_got; 	instr_got = arc_gen_branch(test->pc, test->target_address);	if (instr_got == test->expected_instr)		return 0; 	pr_err(SELFTEST_MSG "FAIL:\n arc_gen_branch(0x%08x, 0x%08x) != 0x%08x, got 0x%08x\n",	       test->pc, test->target_address,	       test->expected_instr, instr_got); 	return -EFAULT;} /* * Offset field in branch instruction is not continuous. Test all * available offset field and sign combinations. Test data is generated * from real working code. */static const struct arc_gen_branch_testdata arcgenbr_test_data[] __initconst = {	{0x90007548, 0x90007514, 0xffcf07cd}, /* tiny (-52) offs */	{0x9000c9c0, 0x9000c782, 0xffcf05c3}, /* tiny (-574) offs */	{0x9000cc1c, 0x9000c782, 0xffcf0367}, /* tiny (-1178) offs */	{0x9009dce0, 0x9009d106, 0xff8f0427}, /* small (-3034) offs */	{0x9000f5de, 0x90007d30, 0xfc0f0755}, /* big  (-30892) offs */	{0x900a2444, 0x90035f64, 0xc9cf0321}, /* huge (-443616) offs */	{0x90007514, 0x9000752c, 0x00000019}, /* tiny (+24) offs */	{0x9001a578, 0x9001a77a, 0x00000203}, /* tiny (+514) offs */	{0x90031ed8, 0x90032634, 0x0000075d}, /* tiny (+1884) offs */	{0x9008c7f2, 0x9008d3f0, 0x00400401}, /* small (+3072) offs */	{0x9000bb38, 0x9003b340, 0x17c00009}, /* big  (+194568) offs */	{0x90008f44, 0x90578d80, 0xb7c2063d}  /* huge (+5701180) offs */}; static __init int instr_gen_test(void){	int i; 	for (i = 0; i < ARRAY_SIZE(arcgenbr_test_data); i++)		if (branch_gen_test(&arcgenbr_test_data[i]))			return -EFAULT; 	pr_info(SELFTEST_MSG "OK\n"); 	return 0;}early_initcall(instr_gen_test); #endif /* CONFIG_ARC_DBG_JUMP_LABEL */