[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <1381675827-1610-5-git-send-email-liuj97@gmail.com>
Date: Sun, 13 Oct 2013 22:50:24 +0800
From: Jiang Liu <liuj97@...il.com>
To: Steven Rostedt <rostedt@...dmis.org>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Sandeepa Prabhu <sandeepa.prabhu@...aro.org>,
Jiang Liu <jiang.liu@...wei.com>,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc: Jiang Liu <liuj97@...il.com>
Subject: [PATCH v2 4/7] arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functions
From: Jiang Liu <jiang.liu@...wei.com>
Introduce aarch64_insn_gen_{nop|branch_imm}() helper functions, which
will be used to implement jump label on ARM64.
Signed-off-by: Jiang Liu <jiang.liu@...wei.com>
Cc: Jiang Liu <liuj97@...il.com>
---
arch/arm64/include/asm/insn.h | 7 +++++++
arch/arm64/kernel/insn.c | 27 +++++++++++++++++++++++++++
2 files changed, 34 insertions(+)
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 8dc0a91..87c44b2 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -61,6 +61,13 @@ __AARCH64_INSN_FUNCS(nop, 0xFFFFFFFF, 0xD503201F)
enum aarch64_insn_class aarch64_get_insn_class(u32 insn);
u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
u32 insn, u64 imm);
+u32 aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
+ bool link);
+static __always_inline u32 aarch64_insn_gen_nop(void)
+{
+ return aarch64_insn_get_nop_value();
+}
+
u32 aarch64_insn_read(void *addr);
void aarch64_insn_write(void *addr, u32 insn);
bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn);
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index a0f60cc..66211bb 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/kernel.h>
#include <linux/stop_machine.h>
#include <asm/cacheflush.h>
@@ -261,3 +262,29 @@ u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
return insn;
}
+
+u32 aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr, bool link)
+{
+ u32 insn;
+ long offset;
+
+ /*
+ * PC: A 64-bit Program Counter holding the address of the current
+ * instruction. A64 instructions may be word-aligned.
+ */
+ BUG_ON((pc & 0x3) || (addr & 0x3));
+
+ /* B/BR support [-128M, 128M) offset */
+ offset = ((long)addr - (long)pc) >> 2;
+ if (offset >= BIT(25) || abs(offset) > BIT(25)) {
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ if (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);
+}
--
1.8.1.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists