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author | Jiang Liu <liuj97@gmail.com> | 2014-01-07 22:17:11 +0800 |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-01-08 15:21:29 +0000 |
commit | 5c5bf25d4f7a950382f94fc120a5818197b48fe9 (patch) | |
tree | c5b7ade94cccaec0e8ab746a704f534b5748f4f6 /arch/arm64/kernel/insn.c | |
parent | c84fced8d990dd86c523233d38b4685a52a4fc3f (diff) | |
download | linux-stable-5c5bf25d4f7a950382f94fc120a5818197b48fe9.tar.gz linux-stable-5c5bf25d4f7a950382f94fc120a5818197b48fe9.tar.bz2 linux-stable-5c5bf25d4f7a950382f94fc120a5818197b48fe9.zip |
arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functions
Introduce aarch64_insn_gen_{nop|branch_imm}() helper functions, which
will be used to implement jump label on ARM64.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/insn.c')
-rw-r--r-- | arch/arm64/kernel/insn.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 7df08075fc7a..92f36835486b 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -14,6 +14,7 @@ * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/bitops.h> #include <linux/compiler.h> #include <linux/kernel.h> #include <linux/smp.h> @@ -262,3 +263,42 @@ u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type, return insn; } + +u32 __kprobes aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr, + enum aarch64_insn_branch_type type) +{ + u32 insn; + long offset; + + /* + * PC: A 64-bit Program Counter holding the address of the current + * instruction. A64 instructions must be word-aligned. + */ + BUG_ON((pc & 0x3) || (addr & 0x3)); + + /* + * B/BL support [-128M, 128M) offset + * ARM64 virtual address arrangement guarantees all kernel and module + * texts are within +/-128M. + */ + offset = ((long)addr - (long)pc); + BUG_ON(offset < -SZ_128M || offset >= SZ_128M); + + if (type == AARCH64_INSN_BRANCH_LINK) + insn = aarch64_insn_get_bl_value(); + else + insn = aarch64_insn_get_b_value(); + + return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_26, insn, + offset >> 2); +} + +u32 __kprobes aarch64_insn_gen_hint(enum aarch64_insn_hint_op op) +{ + return aarch64_insn_get_hint_value() | op; +} + +u32 __kprobes aarch64_insn_gen_nop(void) +{ + return aarch64_insn_gen_hint(AARCH64_INSN_HINT_NOP); +} |