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Date: Wed, 30 Sep 2015 10:11:45 +0800
From: Zhigang Lu <zlu@...hip.com>
To: <linux-kernel@...r.kernel.org>, <cmetcalf@...hip.com>
CC: Zhigang Lu <zlu@...hip.com>
Subject: [PATCH 2/2] tile/jump_label: add jump label support for TILE-Gx
Add the arch-specific code to support jump label for TILE-Gx. This
code shares NOP instruction with ftrace, so we move it to a common
header file.
Reviewed-by: Chris Metcalf <cmetcalf@...hip.com>
Signed-off-by: Zhigang Lu <zlu@...hip.com>
---
arch/tile/Kconfig | 1 +
arch/tile/include/asm/insn.h | 59 +++++++++++++++++++++++++++++++++++
arch/tile/include/asm/jump_label.h | 58 ++++++++++++++++++++++++++++++++++
arch/tile/kernel/Makefile | 1 +
arch/tile/kernel/ftrace.c | 11 +------
arch/tile/kernel/jump_label.c | 64 ++++++++++++++++++++++++++++++++++++++
6 files changed, 184 insertions(+), 10 deletions(-)
create mode 100644 arch/tile/include/asm/insn.h
create mode 100644 arch/tile/include/asm/jump_label.h
create mode 100644 arch/tile/kernel/jump_label.c
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 106c21b..dff39e2 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -33,6 +33,7 @@ config TILE
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select HAVE_ARCH_SECCOMP_FILTER
+ select HAVE_ARCH_JUMP_LABEL
# FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT
diff --git a/arch/tile/include/asm/insn.h b/arch/tile/include/asm/insn.h
new file mode 100644
index 0000000..f78ba5c
--- /dev/null
+++ b/arch/tile/include/asm/insn.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2015 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+#ifndef __ASM_TILE_INSN_H
+#define __ASM_TILE_INSN_H
+
+#include <arch/opcode.h>
+
+static inline tilegx_bundle_bits NOP(void)
+{
+ return create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) |
+ create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) |
+ create_Opcode_X0(RRR_0_OPCODE_X0) |
+ create_UnaryOpcodeExtension_X1(NOP_UNARY_OPCODE_X1) |
+ create_RRROpcodeExtension_X1(UNARY_RRR_0_OPCODE_X1) |
+ create_Opcode_X1(RRR_0_OPCODE_X1);
+}
+
+static inline tilegx_bundle_bits tilegx_gen_branch(unsigned long pc,
+ unsigned long addr,
+ bool link)
+{
+ tilegx_bundle_bits opcode_x0, opcode_x1;
+ long pcrel_by_instr = (addr - pc) >> TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES;
+
+ if (link) {
+ /* opcode: jal addr */
+ opcode_x1 =
+ create_Opcode_X1(JUMP_OPCODE_X1) |
+ create_JumpOpcodeExtension_X1(JAL_JUMP_OPCODE_X1) |
+ create_JumpOff_X1(pcrel_by_instr);
+ } else {
+ /* opcode: j addr */
+ opcode_x1 =
+ create_Opcode_X1(JUMP_OPCODE_X1) |
+ create_JumpOpcodeExtension_X1(J_JUMP_OPCODE_X1) |
+ create_JumpOff_X1(pcrel_by_instr);
+ }
+
+ /* opcode: fnop */
+ opcode_x0 =
+ create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) |
+ create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) |
+ create_Opcode_X0(RRR_0_OPCODE_X0);
+
+ return opcode_x1 | opcode_x0;
+}
+
+#endif /* __ASM_TILE_INSN_H */
diff --git a/arch/tile/include/asm/jump_label.h b/arch/tile/include/asm/jump_label.h
new file mode 100644
index 0000000..cde7573
--- /dev/null
+++ b/arch/tile/include/asm/jump_label.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2015 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#ifndef _ASM_TILE_JUMP_LABEL_H
+#define _ASM_TILE_JUMP_LABEL_H
+
+#include <arch/opcode.h>
+
+#define JUMP_LABEL_NOP_SIZE TILE_BUNDLE_SIZE_IN_BYTES
+
+static __always_inline bool arch_static_branch(struct static_key *key,
+ bool branch)
+{
+ asm_volatile_goto("1:\n\t"
+ "nop" "\n\t"
+ ".pushsection __jump_table, \"aw\"\n\t"
+ ".quad 1b, %l[l_yes], %0 + %1 \n\t"
+ ".popsection\n\t"
+ : : "i" (key), "i" (branch) : : l_yes);
+ return false;
+l_yes:
+ return true;
+}
+
+static __always_inline bool arch_static_branch_jump(struct static_key *key,
+ bool branch)
+{
+ asm_volatile_goto("1:\n\t"
+ "j %l[l_yes]" "\n\t"
+ ".pushsection __jump_table, \"aw\"\n\t"
+ ".quad 1b, %l[l_yes], %0 + %1 \n\t"
+ ".popsection\n\t"
+ : : "i" (key), "i" (branch) : : l_yes);
+ return false;
+l_yes:
+ return true;
+}
+
+typedef u64 jump_label_t;
+
+struct jump_entry {
+ jump_label_t code;
+ jump_label_t target;
+ jump_label_t key;
+};
+
+#endif /* _ASM_TILE_JUMP_LABEL_H */
diff --git a/arch/tile/kernel/Makefile b/arch/tile/kernel/Makefile
index 21f77bf..09936d0 100644
--- a/arch/tile/kernel/Makefile
+++ b/arch/tile/kernel/Makefile
@@ -32,5 +32,6 @@ obj-$(CONFIG_TILE_HVGLUE_TRACE) += hvglue_trace.o
obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o mcount_64.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_KGDB) += kgdb.o
+obj-$(CONFIG_JUMP_LABEL) += jump_label.o
obj-y += vdso/
diff --git a/arch/tile/kernel/ftrace.c b/arch/tile/kernel/ftrace.c
index 4180ccdf..4a57208 100644
--- a/arch/tile/kernel/ftrace.c
+++ b/arch/tile/kernel/ftrace.c
@@ -20,21 +20,12 @@
#include <asm/cacheflush.h>
#include <asm/ftrace.h>
#include <asm/sections.h>
+#include <asm/insn.h>
#include <arch/opcode.h>
#ifdef CONFIG_DYNAMIC_FTRACE
-static inline tilegx_bundle_bits NOP(void)
-{
- return create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) |
- create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) |
- create_Opcode_X0(RRR_0_OPCODE_X0) |
- create_UnaryOpcodeExtension_X1(NOP_UNARY_OPCODE_X1) |
- create_RRROpcodeExtension_X1(UNARY_RRR_0_OPCODE_X1) |
- create_Opcode_X1(RRR_0_OPCODE_X1);
-}
-
static int machine_stopped __read_mostly;
int ftrace_arch_code_modify_prepare(void)
diff --git a/arch/tile/kernel/jump_label.c b/arch/tile/kernel/jump_label.c
new file mode 100644
index 0000000..07802d5
--- /dev/null
+++ b/arch/tile/kernel/jump_label.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2015 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * jump label TILE-Gx support
+ */
+
+#include <linux/jump_label.h>
+#include <linux/memory.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/cpu.h>
+
+#include <asm/cacheflush.h>
+#include <asm/insn.h>
+
+#ifdef HAVE_JUMP_LABEL
+
+static void __jump_label_transform(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ tilegx_bundle_bits opcode;
+ /* Operate on writable kernel text mapping. */
+ unsigned long pc_wr = ktext_writable_addr(e->code);
+
+ if (type == JUMP_LABEL_JMP)
+ opcode = tilegx_gen_branch(e->code, e->target, false);
+ else
+ opcode = NOP();
+
+ *(tilegx_bundle_bits *)pc_wr = opcode;
+ /* Make sure that above mem writes were issued towards the memory. */
+ smp_wmb();
+}
+
+void arch_jump_label_transform(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ get_online_cpus();
+ mutex_lock(&text_mutex);
+
+ __jump_label_transform(e, type);
+ flush_icache_range(e->code, e->code + sizeof(tilegx_bundle_bits));
+
+ mutex_unlock(&text_mutex);
+ put_online_cpus();
+}
+
+__init_or_module void arch_jump_label_transform_static(struct jump_entry *e,
+ enum jump_label_type type)
+{
+ __jump_label_transform(e, type);
+}
+
+#endif /* HAVE_JUMP_LABEL */
--
2.1.2
--
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