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Commit 4e078a81 authored by Juerg Haefliger's avatar Juerg Haefliger Committed by Stefan Bader
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Revert "s390: introduce CPU alternatives" 

BugLink: http://bugs.launchpad.net/bugs/1768474

This reverts commit 008e2cfd to be
replaced by the upstream patch set from 4.4.130.
Signed-off-by: default avatarJuerg Haefliger <juergh@canonical.com>
Signed-off-by: default avatarKleber Sacilotto de Souza <kleber.souza@canonical.com>
parent d898c7fa
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Showing with 1 addition and 299 deletions
arch/s390/include/asm/alternative.h deleted 100644 → 0
View file @ d898c7fa
#ifndef _ASM_S390_ALTERNATIVE_H
#define _ASM_S390_ALTERNATIVE_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/stringify.h>
struct alt_instr {
s32 instr_offset; /* original instruction */
s32 repl_offset; /* offset to replacement instruction */
u16 facility; /* facility bit set for replacement */
u8 instrlen; /* length of original instruction */
u8 replacementlen; /* length of new instruction */
} __packed;
extern void apply_alternative_instructions(void);
extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
/*
* |661: |662: |6620 |663:
* +-----------+---------------------+
* | oldinstr | oldinstr_padding |
* | +----------+----------+
* | | | |
* | | >6 bytes |6/4/2 nops|
* | |6 bytes jg----------->
* +-----------+---------------------+
* ^^ static padding ^^
*
* .altinstr_replacement section
* +---------------------+-----------+
* |6641: |6651:
* | alternative instr 1 |
* +-----------+---------+- - - - - -+
* |6642: |6652: |
* | alternative instr 2 | padding
* +---------------------+- - - - - -+
* ^ runtime ^
*
* .altinstructions section
* +---------------------------------+
* | alt_instr entries for each |
* | alternative instr |
* +---------------------------------+
*/
#define b_altinstr(num) "664"#num
#define e_altinstr(num) "665"#num
#define e_oldinstr_pad_end "663"
#define oldinstr_len "662b-661b"
#define oldinstr_total_len e_oldinstr_pad_end"b-661b"
#define altinstr_len(num) e_altinstr(num)"b-"b_altinstr(num)"b"
#define oldinstr_pad_len(num) \
"-(((" altinstr_len(num) ")-(" oldinstr_len ")) > 0) * " \
"((" altinstr_len(num) ")-(" oldinstr_len "))"
#define INSTR_LEN_SANITY_CHECK(len) \
".if " len " > 254\n" \
"\t.error \"cpu alternatives does not support instructions " \
"blocks > 254 bytes\"\n" \
".endif\n" \
".if (" len ") %% 2\n" \
"\t.error \"cpu alternatives instructions length is odd\"\n" \
".endif\n"
#define OLDINSTR_PADDING(oldinstr, num) \
".if " oldinstr_pad_len(num) " > 6\n" \
"\tjg " e_oldinstr_pad_end "f\n" \
"6620:\n" \
"\t.fill (" oldinstr_pad_len(num) " - (6620b-662b)) / 2, 2, 0x0700\n" \
".else\n" \
"\t.fill " oldinstr_pad_len(num) " / 6, 6, 0xc0040000\n" \
"\t.fill " oldinstr_pad_len(num) " %% 6 / 4, 4, 0x47000000\n" \
"\t.fill " oldinstr_pad_len(num) " %% 6 %% 4 / 2, 2, 0x0700\n" \
".endif\n"
#define OLDINSTR(oldinstr, num) \
"661:\n\t" oldinstr "\n662:\n" \
OLDINSTR_PADDING(oldinstr, num) \
e_oldinstr_pad_end ":\n" \
INSTR_LEN_SANITY_CHECK(oldinstr_len)
#define OLDINSTR_2(oldinstr, num1, num2) \
"661:\n\t" oldinstr "\n662:\n" \
".if " altinstr_len(num1) " < " altinstr_len(num2) "\n" \
OLDINSTR_PADDING(oldinstr, num2) \
".else\n" \
OLDINSTR_PADDING(oldinstr, num1) \
".endif\n" \
e_oldinstr_pad_end ":\n" \
INSTR_LEN_SANITY_CHECK(oldinstr_len)
#define ALTINSTR_ENTRY(facility, num) \
"\t.long 661b - .\n" /* old instruction */ \
"\t.long " b_altinstr(num)"b - .\n" /* alt instruction */ \
"\t.word " __stringify(facility) "\n" /* facility bit */ \
"\t.byte " oldinstr_total_len "\n" /* source len */ \
"\t.byte " altinstr_len(num) "\n" /* alt instruction len */
#define ALTINSTR_REPLACEMENT(altinstr, num) /* replacement */ \
b_altinstr(num)":\n\t" altinstr "\n" e_altinstr(num) ":\n" \
INSTR_LEN_SANITY_CHECK(altinstr_len(num))
/* alternative assembly primitive: */
#define ALTERNATIVE(oldinstr, altinstr, facility) \
".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(altinstr, 1) \
".popsection\n" \
OLDINSTR(oldinstr, 1) \
".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(facility, 1) \
".popsection\n"
#define ALTERNATIVE_2(oldinstr, altinstr1, facility1, altinstr2, facility2)\
".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(altinstr1, 1) \
ALTINSTR_REPLACEMENT(altinstr2, 2) \
".popsection\n" \
OLDINSTR_2(oldinstr, 1, 2) \
".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(facility1, 1) \
ALTINSTR_ENTRY(facility2, 2) \
".popsection\n"
/*
* Alternative instructions for different CPU types or capabilities.
*
* This allows to use optimized instructions even on generic binary
* kernels.
*
* oldinstr is padded with jump and nops at compile time if altinstr is
* longer. altinstr is padded with jump and nops at run-time during patching.
*
* For non barrier like inlines please define new variants
* without volatile and memory clobber.
*/
#define alternative(oldinstr, altinstr, facility) \
asm volatile(ALTERNATIVE(oldinstr, altinstr, facility) : : : "memory")
#define alternative_2(oldinstr, altinstr1, facility1, altinstr2, facility2) \
asm volatile(ALTERNATIVE_2(oldinstr, altinstr1, facility1, \
altinstr2, facility2) ::: "memory")
#endif /* __ASSEMBLY__ */
#endif /* _ASM_S390_ALTERNATIVE_H */
arch/s390/kernel/Makefile
View file @ 4e078a81
......@@ -44,7 +44,7 @@ obj-y += processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
obj-y += debug.o irq.o ipl.o dis.o diag.o sclp.o vdso.o
obj-y += sysinfo.o jump_label.o lgr.o os_info.o machine_kexec.o pgm_check.o
obj-y += runtime_instr.o cache.o dumpstack.o
obj-y += entry.o reipl.o relocate_kernel.o alternative.o
obj-y += entry.o reipl.o relocate_kernel.o
extra-y += head.o head64.o vmlinux.lds
......
arch/s390/kernel/alternative.c deleted 100644 → 0
View file @ d898c7fa
#include <linux/module.h>
#include <asm/alternative.h>
#include <asm/facility.h>
#define MAX_PATCH_LEN (255 - 1)
static int __initdata_or_module alt_instr_disabled;
static int __init disable_alternative_instructions(char *str)
{
alt_instr_disabled = 1;
return 0;
}
early_param("noaltinstr", disable_alternative_instructions);
struct brcl_insn {
u16 opc;
s32 disp;
} __packed;
static u16 __initdata_or_module nop16 = 0x0700;
static u32 __initdata_or_module nop32 = 0x47000000;
static struct brcl_insn __initdata_or_module nop48 = {
0xc004, 0
};
static const void * __initdata_or_module nops[] = {
&nop16,
&nop32,
&nop48
};
static void __init_or_module add_jump_padding(void *insns, unsigned int len)
{
struct brcl_insn brcl = {
0xc0f4,
len / 2
};
memcpy(insns, &brcl, sizeof(brcl));
insns += sizeof(brcl);
len -= sizeof(brcl);
while (len > 0) {
memcpy(insns, &nop16, 2);
insns += 2;
len -= 2;
}
}
static void __init_or_module add_padding(void *insns, unsigned int len)
{
if (len > 6)
add_jump_padding(insns, len);
else if (len >= 2)
memcpy(insns, nops[len / 2 - 1], len);
}
static void __init_or_module __apply_alternatives(struct alt_instr *start,
struct alt_instr *end)
{
struct alt_instr *a;
u8 *instr, *replacement;
u8 insnbuf[MAX_PATCH_LEN];
/*
* The scan order should be from start to end. A later scanned
* alternative code can overwrite previously scanned alternative code.
*/
for (a = start; a < end; a++) {
int insnbuf_sz = 0;
instr = (u8 *)&a->instr_offset + a->instr_offset;
replacement = (u8 *)&a->repl_offset + a->repl_offset;
if (!test_facility(a->facility))
continue;
if (unlikely(a->instrlen % 2 || a->replacementlen % 2)) {
WARN_ONCE(1, "cpu alternatives instructions length is "
"odd, skipping patching\n");
continue;
}
memcpy(insnbuf, replacement, a->replacementlen);
insnbuf_sz = a->replacementlen;
if (a->instrlen > a->replacementlen) {
add_padding(insnbuf + a->replacementlen,
a->instrlen - a->replacementlen);
insnbuf_sz += a->instrlen - a->replacementlen;
}
s390_kernel_write(instr, insnbuf, insnbuf_sz);
}
}
void __init_or_module apply_alternatives(struct alt_instr *start,
struct alt_instr *end)
{
if (!alt_instr_disabled)
__apply_alternatives(start, end);
}
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
void __init apply_alternative_instructions(void)
{
apply_alternatives(__alt_instructions, __alt_instructions_end);
}
arch/s390/kernel/module.c
View file @ 4e078a81
......@@ -31,7 +31,6 @@
#include <linux/kernel.h>
#include <linux/moduleloader.h>
#include <linux/bug.h>
#include <asm/alternative.h>
#if 0
#define DEBUGP printk
......@@ -425,18 +424,6 @@ int module_finalize(const Elf_Ehdr *hdr,
const Elf_Shdr *sechdrs,
struct module *me)
{
const Elf_Shdr *s;
char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
if (!strcmp(".altinstructions", secstrings + s->sh_name)) {
/* patch .altinstructions */
void *aseg = (void *)s->sh_addr;
apply_alternatives(aseg, aseg + s->sh_size);
}
}
jump_label_apply_nops(me);
vfree(me->arch.syminfo);
me->arch.syminfo = NULL;
......
arch/s390/kernel/setup.c
View file @ 4e078a81
......@@ -63,7 +63,6 @@
#include <asm/sclp.h>
#include <asm/sysinfo.h>
#include <asm/numa.h>
#include <asm/alternative.h>
#include "entry.h"
/*
......@@ -894,8 +893,6 @@ void __init setup_arch(char **cmdline_p)
conmode_default();
set_preferred_console();
apply_alternative_instructions();
/* Setup zfcpdump support */
setup_zfcpdump();
......
arch/s390/kernel/vmlinux.lds.S
View file @ 4e078a81
......@@ -78,29 +78,6 @@ SECTIONS
EXIT_DATA
}
/*
* struct alt_inst entries. From the header (alternative.h):
* "Alternative instructions for different CPU types or capabilities"
* Think locking instructions on spinlocks.
* Note, that it is a part of __init region.
*/
. = ALIGN(8);
.altinstructions : {
__alt_instructions = .;
*(.altinstructions)
__alt_instructions_end = .;
}
/*
* And here are the replacement instructions. The linker sticks
* them as binary blobs. The .altinstructions has enough data to
* get the address and the length of them to patch the kernel safely.
* Note, that it is a part of __init region.
*/
.altinstr_replacement : {
*(.altinstr_replacement)
}
/* early.c uses stsi, which requires page aligned data. */
. = ALIGN(PAGE_SIZE);
INIT_DATA_SECTION(0x100)
......
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