Commit ebc00dde authored by Emil Renner Berthing's avatar Emil Renner Berthing Committed by Palmer Dabbelt

riscv: Add jump-label implementation

Add jump-label implementation based on the ARM64 version
and add CONFIG_JUMP_LABEL=y to the defconfigs.
Signed-off-by: default avatarEmil Renner Berthing <kernel@esmil.dk>
Reviewed-by: default avatarBjörn Töpel <bjorn.topel@gmail.com>
Tested-by: default avatarBjörn Töpel <bjorn.topel@gmail.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 11a54f42
......@@ -23,7 +23,7 @@
| openrisc: | TODO |
| parisc: | ok |
| powerpc: | ok |
| riscv: | TODO |
| riscv: | ok |
| s390: | ok |
| sh: | TODO |
| sparc: | ok |
......
......@@ -47,6 +47,8 @@ config RISCV
select GENERIC_TIME_VSYSCALL if MMU && 64BIT
select HANDLE_DOMAIN_IRQ
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_KASAN if MMU && 64BIT
select HAVE_ARCH_KGDB
select HAVE_ARCH_KGDB_QXFER_PKT
......
......@@ -17,6 +17,7 @@ CONFIG_BPF_SYSCALL=y
CONFIG_SOC_SIFIVE=y
CONFIG_SOC_VIRT=y
CONFIG_SMP=y
CONFIG_JUMP_LABEL=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_NET=y
......
......@@ -33,6 +33,7 @@ CONFIG_SMP=y
CONFIG_NR_CPUS=2
CONFIG_CMDLINE="earlycon console=ttySIF0"
CONFIG_CMDLINE_FORCE=y
CONFIG_JUMP_LABEL=y
# CONFIG_BLOCK is not set
CONFIG_BINFMT_FLAT=y
# CONFIG_COREDUMP is not set
......
......@@ -30,6 +30,7 @@ CONFIG_MAXPHYSMEM_2GB=y
CONFIG_SMP=y
CONFIG_CMDLINE="root=/dev/vda rw earlycon=uart8250,mmio,0x10000000,115200n8 console=ttyS0"
CONFIG_CMDLINE_FORCE=y
CONFIG_JUMP_LABEL=y
# CONFIG_BLK_DEV_BSG is not set
CONFIG_PARTITION_ADVANCED=y
# CONFIG_MSDOS_PARTITION is not set
......
......@@ -17,6 +17,7 @@ CONFIG_BPF_SYSCALL=y
CONFIG_SOC_VIRT=y
CONFIG_ARCH_RV32I=y
CONFIG_SMP=y
CONFIG_JUMP_LABEL=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
CONFIG_NET=y
......
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2020 Emil Renner Berthing
*
* Based on arch/arm64/include/asm/jump_label.h
*/
#ifndef __ASM_JUMP_LABEL_H
#define __ASM_JUMP_LABEL_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <asm/asm.h>
#define JUMP_LABEL_NOP_SIZE 4
static __always_inline bool arch_static_branch(struct static_key *key,
bool branch)
{
asm_volatile_goto(
" .option push \n\t"
" .option norelax \n\t"
" .option norvc \n\t"
"1: nop \n\t"
" .option pop \n\t"
" .pushsection __jump_table, \"aw\" \n\t"
" .align " RISCV_LGPTR " \n\t"
" .long 1b - ., %l[label] - . \n\t"
" " RISCV_PTR " %0 - . \n\t"
" .popsection \n\t"
: : "i"(&((char *)key)[branch]) : : label);
return false;
label:
return true;
}
static __always_inline bool arch_static_branch_jump(struct static_key *key,
bool branch)
{
asm_volatile_goto(
" .option push \n\t"
" .option norelax \n\t"
" .option norvc \n\t"
"1: jal zero, %l[label] \n\t"
" .option pop \n\t"
" .pushsection __jump_table, \"aw\" \n\t"
" .align " RISCV_LGPTR " \n\t"
" .long 1b - ., %l[label] - . \n\t"
" " RISCV_PTR " %0 - . \n\t"
" .popsection \n\t"
: : "i"(&((char *)key)[branch]) : : label);
return false;
label:
return true;
}
#endif /* __ASSEMBLY__ */
#endif /* __ASM_JUMP_LABEL_H */
......@@ -53,4 +53,6 @@ endif
obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o
obj-$(CONFIG_KGDB) += kgdb.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
clean:
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 Emil Renner Berthing
*
* Based on arch/arm64/kernel/jump_label.c
*/
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/memory.h>
#include <linux/mutex.h>
#include <asm/bug.h>
#include <asm/patch.h>
#define RISCV_INSN_NOP 0x00000013U
#define RISCV_INSN_JAL 0x0000006fU
void arch_jump_label_transform(struct jump_entry *entry,
enum jump_label_type type)
{
void *addr = (void *)jump_entry_code(entry);
u32 insn;
if (type == JUMP_LABEL_JMP) {
long offset = jump_entry_target(entry) - jump_entry_code(entry);
if (WARN_ON(offset & 1 || offset < -524288 || offset >= 524288))
return;
insn = RISCV_INSN_JAL |
(((u32)offset & GENMASK(19, 12)) << (12 - 12)) |
(((u32)offset & GENMASK(11, 11)) << (20 - 11)) |
(((u32)offset & GENMASK(10, 1)) << (21 - 1)) |
(((u32)offset & GENMASK(20, 20)) << (31 - 20));
} else {
insn = RISCV_INSN_NOP;
}
mutex_lock(&text_mutex);
patch_text_nosync(addr, &insn, sizeof(insn));
mutex_unlock(&text_mutex);
}
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.
*/
}
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