// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org)
*
* Modifications for ppc64:
* Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com>
*
* Copyright 2008 Michael Ellerman, IBM Corporation.
*/
#include <linux/types.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/sched/mm.h>
#include <asm/cputable.h>
#include <asm/code-patching.h>
#include <asm/page.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/security_features.h>
#include <asm/firmware.h>
#include <asm/inst.h>
struct fixup_entry {
unsigned long mask;
unsigned long value;
long start_off;
long end_off;
long alt_start_off;
long alt_end_off;
};
static struct ppc_inst *calc_addr(struct fixup_entry *fcur, long offset)
{
/*
* We store the offset to the code as a negative offset from
* the start of the alt_entry, to support the VDSO. This
* routine converts that back into an actual address.
*/
return (struct ppc_inst *)((unsigned long)fcur + offset);
}
static int patch_alt_instruction(struct ppc_inst *src, struct ppc_inst *dest,
struct ppc_inst *alt_start, struct ppc_inst *alt_end)
{
int err;
struct ppc_inst instr;
instr = ppc_inst_read(src);
if (instr_is_relative_branch(*src)) {
struct ppc_inst *target = (struct ppc_inst *)branch_target(src);
/* Branch within the section doesn't need translating */
if (target < alt_start || target > alt_end) {
err = translate_branch(&instr, dest, src);
if (err)
return 1;
}
}
raw_patch_instruction(dest, instr);
return 0;
}
static int patch_feature_section(unsigned long value, struct fixup_entry *fcur)
{
struct ppc_inst *start, *end, *alt_start, *alt_end, *src, *dest, nop;
start = calc_addr(fcur, fcur->start_off);
end = calc_addr(fcur, fcur->end_off);
alt_start = calc_addr(fcur, fcur->alt_start_off);
alt_end = calc_addr(fcur, fcur->alt_end_off);
if ((alt_end - alt_start) > (end - start))
return 1;
if ((value & fcur->mask) == fcur->value)
return 0;
src = alt_start;
dest = start;
for (; src < alt_end; src = ppc_inst_next(src, src),
dest = ppc_inst_next(dest, dest)) {
if (patch_alt_instruction(src, dest, alt_start, alt_end))
return 1;
}
nop = ppc_inst(PPC_INST_NOP);
for (; dest < end; dest = ppc_inst_next(dest, &nop))
raw_patch_instruction(dest, nop);
return 0;
}
void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end)
{
struct fixup_entry *fcur, *fend;
fcur = fixup_start;
fend = fixup_end;
for (; fcur < fend; fcur++) {
if (patch_feature_section(value, fcur)) {
WARN_ON(1);
printk("Unable to patch feature section at %p - %p" \
" with %p - %p\n",
calc_addr(fcur, fcur->start_off),
calc_addr(fcur, fcur->end_off),
calc_addr(fcur, fcur->alt_start_off),
calc_addr(fcur, fcur->alt_end_off));
}
}
}
#ifdef CONFIG_PPC_BOOK3S_64
static void do_stf_entry_barrier_fixups(enum stf_barrier_type types)
{
unsigned int instrs[3], *dest;
long *start, *end;
int i;
start = PTRRELOC(&__start___stf_entry_barrier_fixup),
end = PTRRELOC(&__stop___stf_entry_barrier_fixup);
instrs[0] = 0x60000000; /* nop */
instrs[1] = 0x60000000; /* nop */
instrs[2] = 0x60000000; /* nop */
i = 0;
if (types & STF_BARRIER_FALLBACK) {
instrs[i++] = 0x7d4802a6; /* mflr r10 */
instrs[i++] = 0x60000000; /* branch patched below */
instrs[i++] = 0x7d4803a6; /* mtlr r10 */
} else if (types & STF_BARRIER_EIEIO) {
instrs[i++] = 0x7e0006ac; /* eieio + bit 6 hint */
} else if (types & STF_BARRIER_SYNC_ORI) {
instrs[i++] = 0x7c0004ac; /* hwsync */
instrs[i++] = 0xe94d0000; /* ld r10,0(r13) */
instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */
}
for (i = 0; start < end