diff options
Diffstat (limited to 'arch/csky/kernel/jump_label.c')
-rw-r--r-- | arch/csky/kernel/jump_label.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/csky/kernel/jump_label.c b/arch/csky/kernel/jump_label.c new file mode 100644 index 0000000000..d0e8b21447 --- /dev/null +++ b/arch/csky/kernel/jump_label.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/jump_label.h> +#include <linux/kernel.h> +#include <linux/memory.h> +#include <linux/mutex.h> +#include <linux/uaccess.h> +#include <asm/cacheflush.h> + +#define NOP32_HI 0xc400 +#define NOP32_LO 0x4820 +#define BSR_LINK 0xe000 + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + unsigned long addr = jump_entry_code(entry); + u16 insn[2]; + int ret = 0; + + if (type == JUMP_LABEL_JMP) { + long offset = jump_entry_target(entry) - jump_entry_code(entry); + + if (WARN_ON(offset & 1 || offset < -67108864 || offset >= 67108864)) + return; + + offset = offset >> 1; + + insn[0] = BSR_LINK | + ((uint16_t)((unsigned long) offset >> 16) & 0x3ff); + insn[1] = (uint16_t)((unsigned long) offset & 0xffff); + } else { + insn[0] = NOP32_HI; + insn[1] = NOP32_LO; + } + + ret = copy_to_kernel_nofault((void *)addr, insn, 4); + WARN_ON(ret); + + flush_icache_range(addr, addr + 4); +} + +void arch_jump_label_transform_static(struct jump_entry *entry, + enum jump_label_type type) +{ + /* + * We use the same instructions in the arch_static_branch and + * arch_static_branch_jump inline functions, so there's no + * need to patch them up here. + * The core will call arch_jump_label_transform when those + * instructions need to be replaced. + */ + arch_jump_label_transform(entry, type); +} |