96 lines
2.1 KiB
C
96 lines
2.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
// Copyright (C) 2018 Cadence Design Systems Inc.
|
|
|
|
#include <linux/cpu.h>
|
|
#include <linux/jump_label.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/memory.h>
|
|
#include <linux/stop_machine.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
|
|
#define J_OFFSET_MASK 0x0003ffff
|
|
#define J_SIGN_MASK (~(J_OFFSET_MASK >> 1))
|
|
|
|
#if defined(__XTENSA_EL__)
|
|
#define J_INSN 0x6
|
|
#define NOP_INSN 0x0020f0
|
|
#elif defined(__XTENSA_EB__)
|
|
#define J_INSN 0x60000000
|
|
#define NOP_INSN 0x0f020000
|
|
#else
|
|
#error Unsupported endianness.
|
|
#endif
|
|
|
|
struct patch {
|
|
atomic_t cpu_count;
|
|
unsigned long addr;
|
|
size_t sz;
|
|
const void *data;
|
|
};
|
|
|
|
static void local_patch_text(unsigned long addr, const void *data, size_t sz)
|
|
{
|
|
memcpy((void *)addr, data, sz);
|
|
local_flush_icache_range(addr, addr + sz);
|
|
}
|
|
|
|
static int patch_text_stop_machine(void *data)
|
|
{
|
|
struct patch *patch = data;
|
|
|
|
if (atomic_inc_return(&patch->cpu_count) == 1) {
|
|
local_patch_text(patch->addr, patch->data, patch->sz);
|
|
atomic_inc(&patch->cpu_count);
|
|
} else {
|
|
while (atomic_read(&patch->cpu_count) <= num_online_cpus())
|
|
cpu_relax();
|
|
__invalidate_icache_range(patch->addr, patch->sz);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void patch_text(unsigned long addr, const void *data, size_t sz)
|
|
{
|
|
if (IS_ENABLED(CONFIG_SMP)) {
|
|
struct patch patch = {
|
|
.cpu_count = ATOMIC_INIT(0),
|
|
.addr = addr,
|
|
.sz = sz,
|
|
.data = data,
|
|
};
|
|
stop_machine_cpuslocked(patch_text_stop_machine,
|
|
&patch, NULL);
|
|
} else {
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
local_patch_text(addr, data, sz);
|
|
local_irq_restore(flags);
|
|
}
|
|
}
|
|
|
|
void arch_jump_label_transform(struct jump_entry *e,
|
|
enum jump_label_type type)
|
|
{
|
|
u32 d = (jump_entry_target(e) - (jump_entry_code(e) + 4));
|
|
u32 insn;
|
|
|
|
/* Jump only works within 128K of the J instruction. */
|
|
BUG_ON(!((d & J_SIGN_MASK) == 0 ||
|
|
(d & J_SIGN_MASK) == J_SIGN_MASK));
|
|
|
|
if (type == JUMP_LABEL_JMP) {
|
|
#if defined(__XTENSA_EL__)
|
|
insn = ((d & J_OFFSET_MASK) << 6) | J_INSN;
|
|
#elif defined(__XTENSA_EB__)
|
|
insn = ((d & J_OFFSET_MASK) << 8) | J_INSN;
|
|
#endif
|
|
} else {
|
|
insn = NOP_INSN;
|
|
}
|
|
|
|
patch_text(jump_entry_code(e), &insn, JUMP_LABEL_NOP_SIZE);
|
|
}
|