mips: Add support for generic vDSO

The mips vDSO library requires some adaptations to take advantage of the
newly introduced generic vDSO library.

Introduce the following changes:
 - Modification of vdso.c to be compliant with the common vdso datapage
 - Use of lib/vdso for gettimeofday

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
[paul.burton@mips.com: Prepend $(src) to config-n32-o32-env.c path.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
This commit is contained in:
Vincenzo Frascino 2019-06-21 10:52:46 +01:00 committed by Paul Burton
parent c2aeaaea17
commit 24640f233b
No known key found for this signature in database
GPG Key ID: 3EA79FACB57500DD
11 changed files with 296 additions and 115 deletions

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@ -22,6 +22,7 @@ config MIPS
select GENERIC_CLOCKEVENTS
select GENERIC_CMOS_UPDATE
select GENERIC_CPU_AUTOPROBE
select GENERIC_GETTIMEOFDAY
select GENERIC_IOMAP
select GENERIC_IRQ_PROBE
select GENERIC_IRQ_SHOW
@ -74,6 +75,7 @@ config MIPS
select HAVE_STACKPROTECTOR
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP
select HAVE_GENERIC_VDSO
select IRQ_FORCED_THREADING
select ISA if EISA
select MODULES_USE_ELF_RELA if MODULES && 64BIT

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@ -8,6 +8,7 @@
#define __ASM_VDSO_H
#include <linux/mm_types.h>
#include <vdso/datapage.h>
#include <asm/barrier.h>
@ -49,84 +50,9 @@ extern struct mips_vdso_image vdso_image_o32;
extern struct mips_vdso_image vdso_image_n32;
#endif
/**
* union mips_vdso_data - Data provided by the kernel for the VDSO.
* @xtime_sec: Current real time (seconds part).
* @xtime_nsec: Current real time (nanoseconds part, shifted).
* @wall_to_mono_sec: Wall-to-monotonic offset (seconds part).
* @wall_to_mono_nsec: Wall-to-monotonic offset (nanoseconds part).
* @seq_count: Counter to synchronise updates (odd = updating).
* @cs_shift: Clocksource shift value.
* @clock_mode: Clocksource to use for time functions.
* @cs_mult: Clocksource multiplier value.
* @cs_cycle_last: Clock cycle value at last update.
* @cs_mask: Clocksource mask value.
* @tz_minuteswest: Minutes west of Greenwich (from timezone).
* @tz_dsttime: Type of DST correction (from timezone).
*
* This structure contains data needed by functions within the VDSO. It is
* populated by the kernel and mapped read-only into user memory. The time
* fields are mirrors of internal data from the timekeeping infrastructure.
*
* Note: Care should be taken when modifying as the layout must remain the same
* for both 64- and 32-bit (for 32-bit userland on 64-bit kernel).
*/
union mips_vdso_data {
struct {
u64 xtime_sec;
u64 xtime_nsec;
u64 wall_to_mono_sec;
u64 wall_to_mono_nsec;
u32 seq_count;
u32 cs_shift;
u8 clock_mode;
u32 cs_mult;
u64 cs_cycle_last;
u64 cs_mask;
s32 tz_minuteswest;
s32 tz_dsttime;
};
struct vdso_data data[CS_BASES];
u8 page[PAGE_SIZE];
};
static inline u32 vdso_data_read_begin(const union mips_vdso_data *data)
{
u32 seq;
while (true) {
seq = READ_ONCE(data->seq_count);
if (likely(!(seq & 1))) {
/* Paired with smp_wmb() in vdso_data_write_*(). */
smp_rmb();
return seq;
}
cpu_relax();
}
}
static inline bool vdso_data_read_retry(const union mips_vdso_data *data,
u32 start_seq)
{
/* Paired with smp_wmb() in vdso_data_write_*(). */
smp_rmb();
return unlikely(data->seq_count != start_seq);
}
static inline void vdso_data_write_begin(union mips_vdso_data *data)
{
++data->seq_count;
/* Ensure sequence update is written before other data page values. */
smp_wmb();
}
static inline void vdso_data_write_end(union mips_vdso_data *data)
{
/* Ensure data values are written before updating sequence again. */
smp_wmb();
++data->seq_count;
}
#endif /* __ASM_VDSO_H */

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@ -0,0 +1,151 @@
/*
* Copyright (C) 2018 ARM Limited
* Copyright (C) 2015 Imagination Technologies
* Author: Alex Smith <alex.smith@imgtec.com>
*
* 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; either version 2 of the License, or (at your
* option) any later version.
*/
#ifndef __ASM_VDSO_GETTIMEOFDAY_H
#define __ASM_VDSO_GETTIMEOFDAY_H
#ifndef __ASSEMBLY__
#include <linux/compiler.h>
#include <linux/time.h>
#include <asm/vdso/vdso.h>
#include <asm/clocksource.h>
#include <asm/io.h>
#include <asm/unistd.h>
#include <asm/vdso.h>
#ifdef CONFIG_MIPS_CLOCK_VSYSCALL
static __always_inline long gettimeofday_fallback(
struct __kernel_old_timeval *_tv,
struct timezone *_tz)
{
register struct timezone *tz asm("a1") = _tz;
register struct __kernel_old_timeval *tv asm("a0") = _tv;
register long ret asm("v0");
register long nr asm("v0") = __NR_gettimeofday;
register long error asm("a3");
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (tv), "r" (tz), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
return error ? -ret : ret;
}
#else
static __always_inline long gettimeofday_fallback(
struct __kernel_old_timeval *_tv,
struct timezone *_tz)
{
return -1;
}
#endif
static __always_inline long clock_gettime_fallback(
clockid_t _clkid,
struct __kernel_timespec *_ts)
{
register struct __kernel_timespec *ts asm("a1") = _ts;
register clockid_t clkid asm("a0") = _clkid;
register long ret asm("v0");
#if _MIPS_SIM == _MIPS_SIM_ABI64
register long nr asm("v0") = __NR_clock_gettime;
#else
register long nr asm("v0") = __NR_clock_gettime64;
#endif
register long error asm("a3");
asm volatile(
" syscall\n"
: "=r" (ret), "=r" (error)
: "r" (clkid), "r" (ts), "r" (nr)
: "$1", "$3", "$8", "$9", "$10", "$11", "$12", "$13",
"$14", "$15", "$24", "$25", "hi", "lo", "memory");
return error ? -ret : ret;
}
#ifdef CONFIG_CSRC_R4K
static __always_inline u64 read_r4k_count(void)
{
unsigned int count;
__asm__ __volatile__(
" .set push\n"
" .set mips32r2\n"
" rdhwr %0, $2\n"
" .set pop\n"
: "=r" (count));
return count;
}
#endif
#ifdef CONFIG_CLKSRC_MIPS_GIC
static __always_inline u64 read_gic_count(const struct vdso_data *data)
{
void __iomem *gic = get_gic(data);
u32 hi, hi2, lo;
do {
hi = __raw_readl(gic + sizeof(lo));
lo = __raw_readl(gic);
hi2 = __raw_readl(gic + sizeof(lo));
} while (hi2 != hi);
return (((u64)hi) << 32) + lo;
}
#endif
static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
{
#ifdef CONFIG_CLKSRC_MIPS_GIC
const struct vdso_data *data = get_vdso_data();
#endif
u64 cycle_now;
switch (clock_mode) {
#ifdef CONFIG_CSRC_R4K
case VDSO_CLOCK_R4K:
cycle_now = read_r4k_count();
break;
#endif
#ifdef CONFIG_CLKSRC_MIPS_GIC
case VDSO_CLOCK_GIC:
cycle_now = read_gic_count(data);
break;
#endif
default:
cycle_now = 0;
break;
}
return cycle_now;
}
static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
{
return get_vdso_data();
}
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_GETTIMEOFDAY_H */

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@ -68,14 +68,14 @@ static inline unsigned long get_vdso_base(void)
return addr;
}
static inline const union mips_vdso_data *get_vdso_data(void)
static inline const struct vdso_data *get_vdso_data(void)
{
return (const union mips_vdso_data *)(get_vdso_base() - PAGE_SIZE);
return (const struct vdso_data *)(get_vdso_base() - PAGE_SIZE);
}
#ifdef CONFIG_CLKSRC_MIPS_GIC
static inline void __iomem *get_gic(const union mips_vdso_data *data)
static inline void __iomem *get_gic(const struct vdso_data *data)
{
return (void __iomem *)data - PAGE_SIZE;
}

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@ -0,0 +1,43 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_VDSO_VSYSCALL_H
#define __ASM_VDSO_VSYSCALL_H
#ifndef __ASSEMBLY__
#include <linux/timekeeper_internal.h>
#include <vdso/datapage.h>
extern struct vdso_data *vdso_data;
/*
* Update the vDSO data page to keep in sync with kernel timekeeping.
*/
static __always_inline
struct vdso_data *__mips_get_k_vdso_data(void)
{
return vdso_data;
}
#define __arch_get_k_vdso_data __mips_get_k_vdso_data
static __always_inline
int __mips_get_clock_mode(struct timekeeper *tk)
{
u32 clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
return clock_mode;
}
#define __arch_get_clock_mode __mips_get_clock_mode
static __always_inline
int __mips_use_vsyscall(struct vdso_data *vdata)
{
return (vdata[CS_HRES_COARSE].clock_mode != VDSO_CLOCK_NONE);
}
#define __arch_use_vsyscall __mips_use_vsyscall
/* The asm-generic header needs to be included after the definitions above */
#include <asm-generic/vdso/vsyscall.h>
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_VDSO_VSYSCALL_H */

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@ -20,9 +20,12 @@
#include <asm/mips-cps.h>
#include <asm/page.h>
#include <asm/vdso.h>
#include <vdso/helpers.h>
#include <vdso/vsyscall.h>
/* Kernel-provided data used by the VDSO. */
static union mips_vdso_data vdso_data __page_aligned_data;
static union mips_vdso_data mips_vdso_data __page_aligned_data;
struct vdso_data *vdso_data = mips_vdso_data.data;
/*
* Mapping for the VDSO data/GIC pages. The real pages are mapped manually, as
@ -66,34 +69,6 @@ static int __init init_vdso(void)
}
subsys_initcall(init_vdso);
void update_vsyscall(struct timekeeper *tk)
{
vdso_data_write_begin(&vdso_data);
vdso_data.xtime_sec = tk->xtime_sec;
vdso_data.xtime_nsec = tk->tkr_mono.xtime_nsec;
vdso_data.wall_to_mono_sec = tk->wall_to_monotonic.tv_sec;
vdso_data.wall_to_mono_nsec = tk->wall_to_monotonic.tv_nsec;
vdso_data.cs_shift = tk->tkr_mono.shift;
vdso_data.clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {
vdso_data.cs_mult = tk->tkr_mono.mult;
vdso_data.cs_cycle_last = tk->tkr_mono.cycle_last;
vdso_data.cs_mask = tk->tkr_mono.mask;
}
vdso_data_write_end(&vdso_data);
}
void update_vsyscall_tz(void)
{
if (vdso_data.clock_mode != VDSO_CLOCK_NONE) {
vdso_data.tz_minuteswest = sys_tz.tz_minuteswest;
vdso_data.tz_dsttime = sys_tz.tz_dsttime;
}
}
static unsigned long vdso_base(void)
{
unsigned long base;
@ -163,7 +138,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
*/
if (cpu_has_dc_aliases) {
base = __ALIGN_MASK(base, shm_align_mask);
base += ((unsigned long)&vdso_data - gic_size) & shm_align_mask;
base += ((unsigned long)vdso_data - gic_size) & shm_align_mask;
}
data_addr = base + gic_size;
@ -189,7 +164,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
/* Map data page. */
ret = remap_pfn_range(vma, data_addr,
virt_to_phys(&vdso_data) >> PAGE_SHIFT,
virt_to_phys(vdso_data) >> PAGE_SHIFT,
PAGE_SIZE, PAGE_READONLY);
if (ret)
goto out;

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@ -1,6 +1,12 @@
# SPDX-License-Identifier: GPL-2.0
# Objects to go into the VDSO.
obj-vdso-y := elf.o gettimeofday.o sigreturn.o
# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
# the inclusion of generic Makefile.
ARCH_REL_TYPE_ABS := R_MIPS_JUMP_SLOT|R_MIPS_GLOB_DAT
include $(srctree)/lib/vdso/Makefile
obj-vdso-y := elf.o vgettimeofday.o sigreturn.o
# Common compiler flags between ABIs.
ccflags-vdso := \
@ -15,15 +21,31 @@ ifdef CONFIG_CC_IS_CLANG
ccflags-vdso += $(filter --target=%,$(KBUILD_CFLAGS))
endif
#
# The -fno-jump-tables flag only prevents the compiler from generating
# jump tables but does not prevent the compiler from emitting absolute
# offsets.
cflags-vdso := $(ccflags-vdso) \
$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
-O2 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
-DDISABLE_BRANCH_PROFILING \
-O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \
-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
$(call cc-option, -fno-asynchronous-unwind-tables) \
$(call cc-option, -fno-stack-protector)
aflags-vdso := $(ccflags-vdso) \
-D__ASSEMBLY__ -Wa,-gdwarf-2
ifneq ($(c-gettimeofday-y),)
CFLAGS_vgettimeofday.o = -include $(c-gettimeofday-y)
# config-n32-o32-env.c prepares the environment to build a 32bit vDSO
# library on a 64bit kernel.
# Note: Needs to be included before than the generic library.
CFLAGS_vgettimeofday-o32.o = -include $(src)/config-n32-o32-env.c -include $(c-gettimeofday-y)
CFLAGS_vgettimeofday-n32.o = -include $(src)/config-n32-o32-env.c -include $(c-gettimeofday-y)
endif
CFLAGS_REMOVE_vgettimeofday.o = -pg
#
# For the pre-R6 code in arch/mips/vdso/vdso.h for locating
# the base address of VDSO, the linker will emit a R_MIPS_PC32
@ -48,6 +70,8 @@ VDSO_LDFLAGS := \
$(addprefix -Wl$(comma),$(filter -E%,$(KBUILD_CFLAGS))) \
-nostdlib -shared -Wl,--hash-style=sysv -Wl,--build-id
CFLAGS_REMOVE_vdso.o = -pg
GCOV_PROFILE := n
UBSAN_SANITIZE := n
@ -96,6 +120,7 @@ $(obj)/vdso.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) $(native-abi)
$(obj)/vdso.so.dbg.raw: $(obj)/vdso.lds $(obj-vdso) FORCE
$(call if_changed,vdsold)
$(call if_changed,vdso_check)
$(obj)/vdso-image.c: $(obj)/vdso.so.dbg.raw $(obj)/vdso.so.raw \
$(obj)/genvdso FORCE
@ -134,6 +159,7 @@ $(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE
$(obj)/vdso-o32.so.dbg.raw: $(obj)/vdso-o32.lds $(obj-vdso-o32) FORCE
$(call if_changed,vdsold)
$(call if_changed,vdso_check)
$(obj)/vdso-o32-image.c: VDSO_NAME := o32
$(obj)/vdso-o32-image.c: $(obj)/vdso-o32.so.dbg.raw $(obj)/vdso-o32.so.raw \
@ -174,6 +200,7 @@ $(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE
$(obj)/vdso-n32.so.dbg.raw: $(obj)/vdso-n32.lds $(obj-vdso-n32) FORCE
$(call if_changed,vdsold)
$(call if_changed,vdso_check)
$(obj)/vdso-n32-image.c: VDSO_NAME := n32
$(obj)/vdso-n32-image.c: $(obj)/vdso-n32.so.dbg.raw $(obj)/vdso-n32.so.raw \

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@ -0,0 +1,17 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Configuration file for O32 and N32 binaries.
* Note: To be included before lib/vdso/gettimeofday.c
*/
#if defined(CONFIG_MIPS32_O32) || defined(CONFIG_MIPS32_N32)
/*
* In case of a 32 bit VDSO for a 64 bit kernel fake a 32 bit kernel
* configuration.
*/
#undef CONFIG_64BIT
#define CONFIG_32BIT 1
#define CONFIG_GENERIC_ATOMIC64 1
#endif

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@ -4,7 +4,7 @@
* Author: Alex Smith <alex.smith@imgtec.com>
*/
#include "vdso.h"
#include <asm/vdso/vdso.h>
#include <asm/isa-rev.h>

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@ -4,7 +4,7 @@
* Author: Alex Smith <alex.smith@imgtec.com>
*/
#include "vdso.h"
#include <asm/vdso/vdso.h>
#include <uapi/asm/unistd.h>

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@ -0,0 +1,40 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* MIPS64 and compat userspace implementations of gettimeofday()
* and similar.
*
* Copyright (C) 2015 Imagination Technologies
* Copyright (C) 2018 ARM Limited
*
*/
#include <linux/time.h>
#include <linux/types.h>
#if _MIPS_SIM != _MIPS_SIM_ABI64
int __vdso_clock_gettime(clockid_t clock,
struct old_timespec32 *ts)
{
return __cvdso_clock_gettime32(clock, ts);
}
int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
struct timezone *tz)
{
return __cvdso_gettimeofday(tv, tz);
}
#else
int __vdso_clock_gettime(clockid_t clock,
struct __kernel_timespec *ts)
{
return __cvdso_clock_gettime(clock, ts);
}
int __vdso_gettimeofday(struct __kernel_old_timeval *tv,
struct timezone *tz)
{
return __cvdso_gettimeofday(tv, tz);
}
#endif