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Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Browse Source 
Pull timer updates from Thomas Gleixner:
 "Nothing exciting, just the usual pile of fixes, updates and cleanups:

   - A bunch of clocksource driver updates

   - Removal of CONFIG_TIMER_STATS and the related /proc file

   - More posix timer slim down work

   - A scalability enhancement in the tick broadcast code

   - Math cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  hrtimer: Catch invalid clockids again
  math64, tile: Fix build failure
  clocksource/drivers/arm_arch_timer:: Mark cyclecounter __ro_after_init
  timerfd: Protect the might cancel mechanism proper
  timer_list: Remove useless cast when printing
  time: Remove CONFIG_TIMER_STATS
  clocksource/drivers/arm_arch_timer: Work around Hisilicon erratum 161010101
  clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure
  clocksource/drivers/arm_arch_timer: Remove fsl-a008585 parameter
  clocksource/drivers/arm_arch_timer: Add dt binding for hisilicon-161010101 erratum
  clocksource/drivers/ostm: Add renesas-ostm timer driver
  clocksource/drivers/ostm: Document renesas-ostm timer DT bindings
  clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock
  clocksource/drivers/gemini: Add driver for the Cortina Gemini
  clocksource: add DT bindings for Cortina Gemini
  clockevents: Add a clkevt-of mechanism like clksrc-of
  tick/broadcast: Reduce lock cacheline contention
  timers: Omit POSIX timer stuff from task_struct when disabled
  x86/timer: Make delay() work during early bootup
  delay: Add explanation of udelay() inaccuracy
  ...
This commit is contained in:
Linus Torvalds 2017-02-20 10:06:32 -08:00
commit 20dcfe1b7d
43 changed files with 1023 additions and 847 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
Documentation/admin-guide/kernel-parameters.txt
View File

@ -549,15 +549,6 @@
loops can be debugged more effectively on production
systems.
clocksource.arm_arch_timer.fsl-a008585=
[ARM64]
Format: <bool>
Enable/disable the workaround of Freescale/NXP
erratum A-008585. This can be useful for KVM
guests, if the guest device tree doesn't show the
erratum. If unspecified, the workaround is
enabled based on the device tree.
clearcpuid=BITNUM [X86]
Disable CPUID feature X for the kernel. See
arch/x86/include/asm/cpufeatures.h for the valid bit

6
Documentation/devicetree/bindings/arm/arch_timer.txt
View File

@ -31,6 +31,12 @@ to deliver its interrupts via SPIs.
This also affects writes to the tval register, due to the implicit
counter read.
- hisilicon,erratum-161010101 : A boolean property. Indicates the
presence of Hisilicon erratum 161010101, which says that reading the
counters is unreliable in some cases, and reads may return a value 32
beyond the correct value. This also affects writes to the tval
registers, due to the implicit counter read.
** Optional properties:
- arm,cpu-registers-not-fw-configured : Firmware does not initialize

22
Documentation/devicetree/bindings/timer/cortina,gemini-timer.txt Normal file
View File

@ -0,0 +1,22 @@
Cortina Systems Gemini timer
This timer is embedded in the Cortina Systems Gemini SoCs.
Required properties:
- compatible : Must be "cortina,gemini-timer"
- reg : Should contain registers location and length
- interrupts : Should contain the three timer interrupts with
flags for rising edge
- syscon : a phandle to the global Gemini system controller
Example:
timer@43000000 {
compatible = "cortina,gemini-timer";
reg = <0x43000000 0x1000>;
interrupts = <14 IRQ_TYPE_EDGE_RISING>, /* Timer 1 */
<15 IRQ_TYPE_EDGE_RISING>, /* Timer 2 */
<16 IRQ_TYPE_EDGE_RISING>; /* Timer 3 */
syscon = <&syscon>;
};

30
Documentation/devicetree/bindings/timer/renesas,ostm.txt Normal file
View File

@ -0,0 +1,30 @@
* Renesas OS Timer (OSTM)
The OSTM is a multi-channel 32-bit timer/counter with fixed clock
source that can operate in either interval count down timer or free-running
compare match mode.
Channels are independent from each other.
Required Properties:
- compatible: must be one or more of the following:
- "renesas,r7s72100-ostm" for the r7s72100 OSTM
- "renesas,ostm" for any OSTM
This is a fallback for the above renesas,*-ostm entries
- reg: base address and length of the register block for a timer channel.
- interrupts: interrupt specifier for the timer channel.
- clocks: clock specifier for the timer channel.
Example: R7S72100 (RZ/A1H) OSTM node
ostm0: timer@fcfec000 {
compatible = "renesas,r7s72100-ostm", "renesas,ostm";
reg = <0xfcfec000 0x30>;
interrupts = <GIC_SPI 102 IRQ_TYPE_EDGE_RISING>;
clocks = <&mstp5_clks R7S72100_CLK_OSTM0>;
power-domains = <&cpg_clocks>;
};

73
Documentation/timers/timer_stats.txt
View File

@ -1,73 +0,0 @@
timer_stats - timer usage statistics
------------------------------------
timer_stats is a debugging facility to make the timer (ab)usage in a Linux
system visible to kernel and userspace developers. If enabled in the config
but not used it has almost zero runtime overhead, and a relatively small
data structure overhead. Even if collection is enabled runtime all the
locking is per-CPU and lookup is hashed.
timer_stats should be used by kernel and userspace developers to verify that
their code does not make unduly use of timers. This helps to avoid unnecessary
wakeups, which should be avoided to optimize power consumption.
It can be enabled by CONFIG_TIMER_STATS in the "Kernel hacking" configuration
section.
timer_stats collects information about the timer events which are fired in a
Linux system over a sample period:
- the pid of the task(process) which initialized the timer
- the name of the process which initialized the timer
- the function where the timer was initialized
- the callback function which is associated to the timer
- the number of events (callbacks)
timer_stats adds an entry to /proc: /proc/timer_stats
This entry is used to control the statistics functionality and to read out the
sampled information.
The timer_stats functionality is inactive on bootup.
To activate a sample period issue:
# echo 1 >/proc/timer_stats
To stop a sample period issue:
# echo 0 >/proc/timer_stats
The statistics can be retrieved by:
# cat /proc/timer_stats
While sampling is enabled, each readout from /proc/timer_stats will see
newly updated statistics. Once sampling is disabled, the sampled information
is kept until a new sample period is started. This allows multiple readouts.
Sample output of /proc/timer_stats:
Timerstats sample period: 3.888770 s
12, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
15, 1 swapper hcd_submit_urb (rh_timer_func)
4, 959 kedac schedule_timeout (process_timeout)
1, 0 swapper page_writeback_init (wb_timer_fn)
28, 0 swapper hrtimer_stop_sched_tick (hrtimer_sched_tick)
22, 2948 IRQ 4 tty_flip_buffer_push (delayed_work_timer_fn)
3, 3100 bash schedule_timeout (process_timeout)
1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
1, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)
1, 1 swapper neigh_table_init_no_netlink (neigh_periodic_timer)
1, 2292 ip __netdev_watchdog_up (dev_watchdog)
1, 23 events/1 do_cache_clean (delayed_work_timer_fn)
90 total events, 30.0 events/sec
The first column is the number of events, the second column the pid, the third
column is the name of the process. The forth column shows the function which
initialized the timer and in parenthesis the callback function which was
executed on expiry.
Thomas, Ingo
Added flag to indicate 'deferrable timer' in /proc/timer_stats. A deferrable
timer will appear as follows
10D, 1 swapper queue_delayed_work_on (delayed_work_timer_fn)

1
arch/arm/mach-shmobile/Kconfig
View File

@ -57,6 +57,7 @@ config ARCH_R7S72100
select PM
select PM_GENERIC_DOMAINS
select SYS_SUPPORTS_SH_MTU2
select RENESAS_OSTM
config ARCH_R8A73A4
bool "R-Mobile APE6 (R8A73A40)"

38
arch/arm64/include/asm/arch_timer.h
View File

@ -29,41 +29,29 @@
#include <clocksource/arm_arch_timer.h>
#if IS_ENABLED(CONFIG_FSL_ERRATUM_A008585)
#if IS_ENABLED(CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND)
extern struct static_key_false arch_timer_read_ool_enabled;
#define needs_fsl_a008585_workaround() \
#define needs_unstable_timer_counter_workaround() \
static_branch_unlikely(&arch_timer_read_ool_enabled)
#else
#define needs_fsl_a008585_workaround() false
#define needs_unstable_timer_counter_workaround() false
#endif
u32 __fsl_a008585_read_cntp_tval_el0(void);
u32 __fsl_a008585_read_cntv_tval_el0(void);
u64 __fsl_a008585_read_cntvct_el0(void);
/*
* The number of retries is an arbitrary value well beyond the highest number
* of iterations the loop has been observed to take.
*/
#define __fsl_a008585_read_reg(reg) ({ \
u64 _old, _new; \
int _retries = 200; \
\
do { \
_old = read_sysreg(reg); \
_new = read_sysreg(reg); \
_retries--; \
} while (unlikely(_old != _new) && _retries); \
\
WARN_ON_ONCE(!_retries); \
_new; \
})
struct arch_timer_erratum_workaround {
const char *id; /* Indicate the Erratum ID */
u32 (*read_cntp_tval_el0)(void);
u32 (*read_cntv_tval_el0)(void);
u64 (*read_cntvct_el0)(void);
};
extern const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround;
#define arch_timer_reg_read_stable(reg) \
({ \
u64 _val; \
if (needs_fsl_a008585_workaround()) \
_val = __fsl_a008585_read_##reg(); \
if (needs_unstable_timer_counter_workaround()) \
_val = timer_unstable_counter_workaround->read_##reg();\
else \
_val = read_sysreg(reg); \
_val; \

1
arch/tile/include/asm/Kbuild
View File

@ -5,7 +5,6 @@ generic-y += bug.h
generic-y += bugs.h
generic-y += clkdev.h
generic-y += cputime.h
generic-y += div64.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += exec.h

16
arch/tile/include/asm/div64.h Normal file
View File

@ -0,0 +1,16 @@
#ifndef _ASM_TILE_DIV64_H
#define _ASM_TILE_DIV64_H
#include <linux/types.h>
#ifdef __tilegx__
static inline u64 mul_u32_u32(u32 a, u32 b)
{
return __insn_mul_lu_lu(a, b);
}
#define mul_u32_u32 mul_u32_u32
#endif
#include <asm-generic/div64.h>
#endif /* _ASM_TILE_DIV64_H */

11
arch/x86/include/asm/div64.h
View File

@ -59,6 +59,17 @@ static inline u64 div_u64_rem(u64 dividend, u32 divisor, u32 *remainder)
}
#define div_u64_rem div_u64_rem
static inline u64 mul_u32_u32(u32 a, u32 b)
{
u32 high, low;
asm ("mull %[b]" : "=a" (low), "=d" (high)
: [a] "a" (a), [b] "rm" (b) );
return low | ((u64)high) << 32;
}
#define mul_u32_u32 mul_u32_u32
#else
# include <asm-generic/div64.h>
#endif /* CONFIG_X86_32 */

4
arch/x86/lib/delay.c
View File

@ -156,13 +156,13 @@ EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
unsigned long lpj = this_cpu_read(cpu_info.loops_per_jiffy) ? : loops_per_jiffy;
int d0;
xloops *= 4;
asm("mull %%edx"
:"=d" (xloops), "=&a" (d0)
:"1" (xloops), "0"
(this_cpu_read(cpu_info.loops_per_jiffy) * (HZ/4)));
:"1" (xloops), "0" (lpj * (HZ / 4)));
__delay(++xloops);
}

38
drivers/clocksource/Kconfig
View File

@ -5,6 +5,10 @@ config CLKSRC_OF
bool
select CLKSRC_PROBE
config CLKEVT_OF
bool
select CLKEVT_PROBE
config CLKSRC_ACPI
bool
select CLKSRC_PROBE
@ -12,6 +16,9 @@ config CLKSRC_ACPI
config CLKSRC_PROBE
bool
config CLKEVT_PROBE
bool
config CLKSRC_I8253
bool
@ -60,6 +67,16 @@ config DW_APB_TIMER_OF
select DW_APB_TIMER
select CLKSRC_OF
config GEMINI_TIMER
bool "Cortina Gemini timer driver" if COMPILE_TEST
depends on GENERIC_CLOCKEVENTS
depends on HAS_IOMEM
select CLKSRC_MMIO
select CLKSRC_OF
select MFD_SYSCON
help
Enables support for the Gemini timer
config ROCKCHIP_TIMER
bool "Rockchip timer driver" if COMPILE_TEST
depends on ARM || ARM64
@ -325,16 +342,30 @@ config ARM_ARCH_TIMER_EVTSTREAM
This must be disabled for hardware validation purposes to detect any
hardware anomalies of missing events.
config ARM_ARCH_TIMER_OOL_WORKAROUND
bool
config FSL_ERRATUM_A008585
bool "Workaround for Freescale/NXP Erratum A-008585"
default y
depends on ARM_ARCH_TIMER && ARM64
select ARM_ARCH_TIMER_OOL_WORKAROUND
help
This option enables a workaround for Freescale/NXP Erratum
A-008585 ("ARM generic timer may contain an erroneous
value"). The workaround will only be active if the
fsl,erratum-a008585 property is found in the timer node.
config HISILICON_ERRATUM_161010101
bool "Workaround for Hisilicon Erratum 161010101"
default y
select ARM_ARCH_TIMER_OOL_WORKAROUND
depends on ARM_ARCH_TIMER && ARM64
help
This option enables a workaround for Hisilicon Erratum
161010101. The workaround will be active if the hisilicon,erratum-161010101
property is found in the timer node.
config ARM_GLOBAL_TIMER
bool "Support for the ARM global timer" if COMPILE_TEST
select CLKSRC_OF if OF
@ -467,6 +498,13 @@ config SH_TIMER_MTU2
Timer Pulse Unit 2 (MTU2) hardware available on SoCs from Renesas.
This hardware comes with 16 bit-timer registers.
config RENESAS_OSTM
bool "Renesas OSTM timer driver" if COMPILE_TEST
depends on GENERIC_CLOCKEVENTS
select CLKSRC_MMIO
help
Enables the support for the Renesas OSTM.
config SH_TIMER_TMU
bool "Renesas TMU timer driver" if COMPILE_TEST
depends on GENERIC_CLOCKEVENTS

3
drivers/clocksource/Makefile
View File

@ -1,4 +1,5 @@
obj-$(CONFIG_CLKSRC_PROBE) += clksrc-probe.o
obj-$(CONFIG_CLKEVT_PROBE) += clkevt-probe.o
obj-$(CONFIG_ATMEL_PIT) += timer-atmel-pit.o
obj-$(CONFIG_ATMEL_ST) += timer-atmel-st.o
obj-$(CONFIG_ATMEL_TCB_CLKSRC) += tcb_clksrc.o
@ -8,6 +9,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o
obj-$(CONFIG_CLKSRC_JCORE_PIT) += jcore-pit.o
obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o
obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o
obj-$(CONFIG_RENESAS_OSTM) += renesas-ostm.o
obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o
obj-$(CONFIG_EM_TIMER_STI) += em_sti.o
obj-$(CONFIG_CLKBLD_I8253) += i8253.o
@ -15,6 +17,7 @@ obj-$(CONFIG_CLKSRC_MMIO) += mmio.o
obj-$(CONFIG_DIGICOLOR_TIMER) += timer-digicolor.o
obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o
obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o
obj-$(CONFIG_GEMINI_TIMER) += timer-gemini.o
obj-$(CONFIG_ROCKCHIP_TIMER) += rockchip_timer.o
obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o
obj-$(CONFIG_CLKSRC_DBX500_PRCMU) += clksrc-dbx500-prcmu.o

155
drivers/clocksource/arm_arch_timer.c
View File

@ -96,41 +96,107 @@ early_param("clocksource.arm_arch_timer.evtstrm", early_evtstrm_cfg);
*/
#ifdef CONFIG_FSL_ERRATUM_A008585
DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled);
EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled);
/*
* The number of retries is an arbitrary value well beyond the highest number
* of iterations the loop has been observed to take.
*/
#define __fsl_a008585_read_reg(reg) ({ \
u64 _old, _new; \
int _retries = 200; \
\
do { \
_old = read_sysreg(reg); \
_new = read_sysreg(reg); \
_retries--; \
} while (unlikely(_old != _new) && _retries); \
\
WARN_ON_ONCE(!_retries); \
_new; \
})
static int fsl_a008585_enable = -1;
static int __init early_fsl_a008585_cfg(char *buf)
{
int ret;
bool val;
ret = strtobool(buf, &val);
if (ret)
return ret;
fsl_a008585_enable = val;
return 0;
}
early_param("clocksource.arm_arch_timer.fsl-a008585", early_fsl_a008585_cfg);
u32 __fsl_a008585_read_cntp_tval_el0(void)
static u32 notrace fsl_a008585_read_cntp_tval_el0(void)
{
return __fsl_a008585_read_reg(cntp_tval_el0);
}
u32 __fsl_a008585_read_cntv_tval_el0(void)
static u32 notrace fsl_a008585_read_cntv_tval_el0(void)
{
return __fsl_a008585_read_reg(cntv_tval_el0);
}
u64 __fsl_a008585_read_cntvct_el0(void)
static u64 notrace fsl_a008585_read_cntvct_el0(void)
{
return __fsl_a008585_read_reg(cntvct_el0);
}
EXPORT_SYMBOL(__fsl_a008585_read_cntvct_el0);
#endif /* CONFIG_FSL_ERRATUM_A008585 */
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161010101
/*
* Verify whether the value of the second read is larger than the first by
* less than 32 is the only way to confirm the value is correct, so clear the
* lower 5 bits to check whether the difference is greater than 32 or not.
* Theoretically the erratum should not occur more than twice in succession
* when reading the system counter, but it is possible that some interrupts
* may lead to more than twice read errors, triggering the warning, so setting
* the number of retries far beyond the number of iterations the loop has been
* observed to take.
*/
#define __hisi_161010101_read_reg(reg) ({ \
u64 _old, _new; \
int _retries = 50; \
\
do { \
_old = read_sysreg(reg); \
_new = read_sysreg(reg); \
_retries--; \
} while (unlikely((_new - _old) >> 5) && _retries); \
\
WARN_ON_ONCE(!_retries); \
_new; \
})
static u32 notrace hisi_161010101_read_cntp_tval_el0(void)
{
return __hisi_161010101_read_reg(cntp_tval_el0);
}
static u32 notrace hisi_161010101_read_cntv_tval_el0(void)
{
return __hisi_161010101_read_reg(cntv_tval_el0);
}
static u64 notrace hisi_161010101_read_cntvct_el0(void)
{
return __hisi_161010101_read_reg(cntvct_el0);
}
#endif
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
const struct arch_timer_erratum_workaround *timer_unstable_counter_workaround = NULL;
EXPORT_SYMBOL_GPL(timer_unstable_counter_workaround);
DEFINE_STATIC_KEY_FALSE(arch_timer_read_ool_enabled);
EXPORT_SYMBOL_GPL(arch_timer_read_ool_enabled);
static const struct arch_timer_erratum_workaround ool_workarounds[] = {
#ifdef CONFIG_FSL_ERRATUM_A008585
{
.id = "fsl,erratum-a008585",
.read_cntp_tval_el0 = fsl_a008585_read_cntp_tval_el0,
.read_cntv_tval_el0 = fsl_a008585_read_cntv_tval_el0,
.read_cntvct_el0 = fsl_a008585_read_cntvct_el0,
},
#endif
#ifdef CONFIG_HISILICON_ERRATUM_161010101
{
.id = "hisilicon,erratum-161010101",
.read_cntp_tval_el0 = hisi_161010101_read_cntp_tval_el0,
.read_cntv_tval_el0 = hisi_161010101_read_cntv_tval_el0,
.read_cntvct_el0 = hisi_161010101_read_cntvct_el0,
},
#endif
};
#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static __always_inline
void arch_timer_reg_write(int access, enum arch_timer_reg reg, u32 val,
@ -281,8 +347,8 @@ static __always_inline void set_next_event(const int access, unsigned long evt,
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
#ifdef CONFIG_FSL_ERRATUM_A008585
static __always_inline void fsl_a008585_set_next_event(const int access,
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
static __always_inline void erratum_set_next_event_generic(const int access,
unsigned long evt, struct clock_event_device *clk)
{
unsigned long ctrl;
@ -300,20 +366,20 @@ static __always_inline void fsl_a008585_set_next_event(const int access,
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, clk);
}
static int fsl_a008585_set_next_event_virt(unsigned long evt,
static int erratum_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
{
fsl_a008585_set_next_event(ARCH_TIMER_VIRT_ACCESS, evt, clk);
erratum_set_next_event_generic(ARCH_TIMER_VIRT_ACCESS, evt, clk);
return 0;
}
static int fsl_a008585_set_next_event_phys(unsigned long evt,
static int erratum_set_next_event_phys(unsigned long evt,
struct clock_event_device *clk)
{
fsl_a008585_set_next_event(ARCH_TIMER_PHYS_ACCESS, evt, clk);
erratum_set_next_event_generic(ARCH_TIMER_PHYS_ACCESS, evt, clk);
return 0;
}
#endif /* CONFIG_FSL_ERRATUM_A008585 */
#endif /* CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND */
static int arch_timer_set_next_event_virt(unsigned long evt,
struct clock_event_device *clk)
@ -343,16 +409,16 @@ static int arch_timer_set_next_event_phys_mem(unsigned long evt,
return 0;
}
static void fsl_a008585_set_sne(struct clock_event_device *clk)
static void erratum_workaround_set_sne(struct clock_event_device *clk)
{
#ifdef CONFIG_FSL_ERRATUM_A008585
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
if (!static_branch_unlikely(&arch_timer_read_ool_enabled))
return;
if (arch_timer_uses_ppi == VIRT_PPI)
clk->set_next_event = fsl_a008585_set_next_event_virt;
clk->set_next_event = erratum_set_next_event_virt;
else
clk->set_next_event = fsl_a008585_set_next_event_phys;
clk->set_next_event = erratum_set_next_event_phys;
#endif
}
@ -385,7 +451,7 @@ static void __arch_timer_setup(unsigned type,
BUG();
}
fsl_a008585_set_sne(clk);
erratum_workaround_set_sne(clk);
} else {
clk->features |= CLOCK_EVT_FEAT_DYNIRQ;
clk->name = "arch_mem_timer";
@ -580,7 +646,7 @@ static struct clocksource clocksource_counter = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct cyclecounter cyclecounter = {
static struct cyclecounter cyclecounter __ro_after_init = {
.read = arch_counter_read_cc,
.mask = CLOCKSOURCE_MASK(56),
};
@ -605,7 +671,7 @@ static void __init arch_counter_register(unsigned type)
clocksource_counter.archdata.vdso_direct = true;
#ifdef CONFIG_FSL_ERRATUM_A008585
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
/*
* Don't use the vdso fastpath if errata require using
* the out-of-line counter accessor.
@ -893,12 +959,15 @@ static int __init arch_timer_of_init(struct device_node *np)
arch_timer_c3stop = !of_property_read_bool(np, "always-on");
#ifdef CONFIG_FSL_ERRATUM_A008585
if (fsl_a008585_enable < 0)
fsl_a008585_enable = of_property_read_bool(np, "fsl,erratum-a008585");
if (fsl_a008585_enable) {
static_branch_enable(&arch_timer_read_ool_enabled);
pr_info("Enabling workaround for FSL erratum A-008585\n");
#ifdef CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND
for (i = 0; i < ARRAY_SIZE(ool_workarounds); i++) {
if (of_property_read_bool(np, ool_workarounds[i].id)) {
timer_unstable_counter_workaround = &ool_workarounds[i];
static_branch_enable(&arch_timer_read_ool_enabled);
pr_info("arch_timer: Enabling workaround for %s\n",
timer_unstable_counter_workaround->id);
break;
}
}
#endif

56
drivers/clocksource/clkevt-probe.c Normal file
View File

@ -0,0 +1,56 @@
/*
* Copyright (c) 2016, Linaro Ltd. All rights reserved.
* Daniel Lezcano <daniel.lezcano@linaro.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/init.h>
#include <linux/of.h>
#include <linux/clockchip.h>
extern struct of_device_id __clkevt_of_table[];
static const struct of_device_id __clkevt_of_table_sentinel
__used __section(__clkevt_of_table_end);
int __init clockevent_probe(void)
{
struct device_node *np;
const struct of_device_id *match;
of_init_fn_1_ret init_func;
int ret, clockevents = 0;
for_each_matching_node_and_match(np, __clkevt_of_table, &match) {
if (!of_device_is_available(np))
continue;
init_func = match->data;
ret = init_func(np);
if (ret) {
pr_warn("Failed to initialize '%s' (%d)\n",
np->name, ret);
continue;
}
clockevents++;
}
if (!clockevents) {
pr_crit("%s: no matching clockevent found\n", __func__);
return -ENODEV;
}
return 0;
}

265
drivers/clocksource/renesas-ostm.c Normal file
View File

@ -0,0 +1,265 @@
/*
* Renesas Timer Support - OSTM
*
* Copyright (C) 2017 Renesas Electronics America, Inc.
* Copyright (C) 2017 Chris Brandt
*
* 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
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/clk.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/sched_clock.h>
#include <linux/slab.h>
/*
* The OSTM contains independent channels.
* The first OSTM channel probed will be set up as a free running
* clocksource. Additionally we will use this clocksource for the system
* schedule timer sched_clock().
*
* The second (or more) channel probed will be set up as an interrupt
* driven clock event.
*/
struct ostm_device {
void __iomem *base;
unsigned long ticks_per_jiffy;
struct clock_event_device ced;
};
static void __iomem *system_clock; /* For sched_clock() */
/* OSTM REGISTERS */
#define OSTM_CMP 0x000 /* RW,32 */
#define OSTM_CNT 0x004 /* R,32 */
#define OSTM_TE 0x010 /* R,8 */
#define OSTM_TS 0x014 /* W,8 */
#define OSTM_TT 0x018 /* W,8 */
#define OSTM_CTL 0x020 /* RW,8 */
#define TE 0x01
#define TS 0x01
#define TT 0x01
#define CTL_PERIODIC 0x00
#define CTL_ONESHOT 0x02
#define CTL_FREERUN 0x02
static struct ostm_device *ced_to_ostm(struct clock_event_device *ced)
{
return container_of(ced, struct ostm_device, ced);
}
static void ostm_timer_stop(struct ostm_device *ostm)
{
if (readb(ostm->base + OSTM_TE) & TE) {
writeb(TT, ostm->base + OSTM_TT);
/*
* Read back the register simply to confirm the write operation
* has completed since I/O writes can sometimes get queued by
* the bus architecture.
*/
while (readb(ostm->base + OSTM_TE) & TE)
;
}
}
static int __init ostm_init_clksrc(struct ostm_device *ostm, unsigned long rate)
{
/*
* irq not used (clock sources don't use interrupts)
*/
ostm_timer_stop(ostm);
writel(0, ostm->base + OSTM_CMP);
writeb(CTL_FREERUN, ostm->base + OSTM_CTL);
writeb(TS, ostm->base + OSTM_TS);
return clocksource_mmio_init(ostm->base + OSTM_CNT,
"ostm", rate,
300, 32, clocksource_mmio_readl_up);
}
static u64 notrace ostm_read_sched_clock(void)
{
return readl(system_clock);
}
static void __init ostm_init_sched_clock(struct ostm_device *ostm,
unsigned long rate)
{
system_clock = ostm->base + OSTM_CNT;
sched_clock_register(ostm_read_sched_clock, 32, rate);
}
static int ostm_clock_event_next(unsigned long delta,
struct clock_event_device *ced)
{
struct ostm_device *ostm = ced_to_ostm(ced);
ostm_timer_stop(ostm);
writel(delta, ostm->base + OSTM_CMP);
writeb(CTL_ONESHOT, ostm->base + OSTM_CTL);
writeb(TS, ostm->base + OSTM_TS);
return 0;
}
static int ostm_shutdown(struct clock_event_device *ced)
{
struct ostm_device *ostm = ced_to_ostm(ced);
ostm_timer_stop(ostm);
return 0;
}
static int ostm_set_periodic(struct clock_event_device *ced)
{
struct ostm_device *ostm = ced_to_ostm(ced);
if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced))
ostm_timer_stop(ostm);
writel(ostm->ticks_per_jiffy - 1, ostm->base + OSTM_CMP);
writeb(CTL_PERIODIC, ostm->base + OSTM_CTL);
writeb(TS, ostm->base + OSTM_TS);
return 0;
}
static int ostm_set_oneshot(struct clock_event_device *ced)
{
struct ostm_device *ostm = ced_to_ostm(ced);
ostm_timer_stop(ostm);
return 0;
}
static irqreturn_t ostm_timer_interrupt(int irq, void *dev_id)
{
struct ostm_device *ostm = dev_id;
if (clockevent_state_oneshot(&ostm->ced))
ostm_timer_stop(ostm);
/* notify clockevent layer */
if (ostm->ced.event_handler)
ostm->ced.event_handler(&ostm->ced);
return IRQ_HANDLED;
}
static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq,
unsigned long rate)
{
struct clock_event_device *ced = &ostm->ced;
int ret = -ENXIO;
ret = request_irq(irq, ostm_timer_interrupt,
IRQF_TIMER | IRQF_IRQPOLL,
"ostm", ostm);
if (ret) {
pr_err("ostm: failed to request irq\n");
return ret;
}
ced->name = "ostm";
ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC;
ced->set_state_shutdown = ostm_shutdown;
ced->set_state_periodic = ostm_set_periodic;
ced->set_state_oneshot = ostm_set_oneshot;
ced->set_next_event = ostm_clock_event_next;
ced->shift = 32;
ced->rating = 300;
ced->cpumask = cpumask_of(0);
clockevents_config_and_register(ced, rate, 0xf, 0xffffffff);
return 0;
}
static int __init ostm_init(struct device_node *np)
{
struct ostm_device *ostm;
int ret = -EFAULT;
struct clk *ostm_clk = NULL;
int irq;
unsigned long rate;
ostm = kzalloc(sizeof(*ostm), GFP_KERNEL);
if (!ostm)
return -ENOMEM;
ostm->base = of_iomap(np, 0);
if (!ostm->base) {
pr_err("ostm: failed to remap I/O memory\n");
goto err;
}
irq = irq_of_parse_and_map(np, 0);
if (irq < 0) {
pr_err("ostm: Failed to get irq\n");
goto err;
}
ostm_clk = of_clk_get(np, 0);
if (IS_ERR(ostm_clk)) {
pr_err("ostm: Failed to get clock\n");
ostm_clk = NULL;
goto err;
}
ret = clk_prepare_enable(ostm_clk);
if (ret) {
pr_err("ostm: Failed to enable clock\n");
goto err;
}
rate = clk_get_rate(ostm_clk);
ostm->ticks_per_jiffy = (rate + HZ / 2) / HZ;
/*
* First probed device will be used as system clocksource. Any
* additional devices will be used as clock events.
*/
if (!system_clock) {
ret = ostm_init_clksrc(ostm, rate);
if (!ret) {
ostm_init_sched_clock(ostm, rate);
pr_info("ostm: used for clocksource\n");
}
} else {
ret = ostm_init_clkevt(ostm, irq, rate);
if (!ret)
pr_info("ostm: used for clock events\n");
}
err:
if (ret) {
clk_disable_unprepare(ostm_clk);
iounmap(ostm->base);
kfree(ostm);
return ret;
}
return 0;
}
CLOCKSOURCE_OF_DECLARE(ostm, "renesas,ostm", ostm_init);

16
drivers/clocksource/tcb_clksrc.c
View File

@ -10,6 +10,7 @@
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/atmel_tc.h>
#include <linux/sched_clock.h>
/*
@ -56,11 +57,16 @@ static u64 tc_get_cycles(struct clocksource *cs)
return (upper << 16) | lower;
}
static u64 tc_get_cycles32(struct clocksource *cs)
static u32 tc_get_cv32(void)
{
return __raw_readl(tcaddr + ATMEL_TC_REG(0, CV));
}
static u64 tc_get_cycles32(struct clocksource *cs)
{
return tc_get_cv32();
}
static struct clocksource clksrc = {
.name = "tcb_clksrc",
.rating = 200,
@ -69,6 +75,11 @@ static struct clocksource clksrc = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u64 notrace tc_read_sched_clock(void)
{
return tc_get_cv32();
}
#ifdef CONFIG_GENERIC_CLOCKEVENTS
struct tc_clkevt_device {
@ -339,6 +350,9 @@ static int __init tcb_clksrc_init(void)
clksrc.read = tc_get_cycles32;
/* setup ony channel 0 */
tcb_setup_single_chan(tc, best_divisor_idx);
/* register sched_clock on chips with single 32 bit counter */
sched_clock_register(tc_read_sched_clock, 32, divided_rate);
} else {
/* tclib will give us three clocks no matter what the
* underlying platform supports.

277
drivers/clocksource/timer-gemini.c Normal file
View File

@ -0,0 +1,277 @@
/*
* Gemini timer driver
* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
*
* Based on a rewrite of arch/arm/mach-gemini/timer.c:
* Copyright (C) 2001-2006 Storlink, Corp.
* Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
*/
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/mfd/syscon.h>
#include <linux/regmap.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/sched_clock.h>
/*
* Relevant registers in the global syscon
*/
#define GLOBAL_STATUS 0x04
#define CPU_AHB_RATIO_MASK (0x3 << 18)
#define CPU_AHB_1_1 (0x0 << 18)
#define CPU_AHB_3_2 (0x1 << 18)
#define CPU_AHB_24_13 (0x2 << 18)
#define CPU_AHB_2_1 (0x3 << 18)
#define REG_TO_AHB_SPEED(reg) ((((reg) >> 15) & 0x7) * 10 + 130)
/*
* Register definitions for the timers
*/
#define TIMER1_COUNT (0x00)
#define TIMER1_LOAD (0x04)
#define TIMER1_MATCH1 (0x08)
#define TIMER1_MATCH2 (0x0c)
#define TIMER2_COUNT (0x10)
#define TIMER2_LOAD (0x14)
#define TIMER2_MATCH1 (0x18)
#define TIMER2_MATCH2 (0x1c)
#define TIMER3_COUNT (0x20)
#define TIMER3_LOAD (0x24)
#define TIMER3_MATCH1 (0x28)
#define TIMER3_MATCH2 (0x2c)
#define TIMER_CR (0x30)
#define TIMER_INTR_STATE (0x34)
#define TIMER_INTR_MASK (0x38)
#define TIMER_1_CR_ENABLE (1 << 0)
#define TIMER_1_CR_CLOCK (1 << 1)
#define TIMER_1_CR_INT (1 << 2)
#define TIMER_2_CR_ENABLE (1 << 3)
#define TIMER_2_CR_CLOCK (1 << 4)
#define TIMER_2_CR_INT (1 << 5)
#define TIMER_3_CR_ENABLE (1 << 6)
#define TIMER_3_CR_CLOCK (1 << 7)
#define TIMER_3_CR_INT (1 << 8)
#define TIMER_1_CR_UPDOWN (1 << 9)
#define TIMER_2_CR_UPDOWN (1 << 10)
#define TIMER_3_CR_UPDOWN (1 << 11)
#define TIMER_DEFAULT_FLAGS (TIMER_1_CR_UPDOWN | \
TIMER_3_CR_ENABLE | \
TIMER_3_CR_UPDOWN)
#define TIMER_1_INT_MATCH1 (1 << 0)
#define TIMER_1_INT_MATCH2 (1 << 1)
#define TIMER_1_INT_OVERFLOW (1 << 2)
#define TIMER_2_INT_MATCH1 (1 << 3)
#define TIMER_2_INT_MATCH2 (1 << 4)
#define TIMER_2_INT_OVERFLOW (1 << 5)
#define TIMER_3_INT_MATCH1 (1 << 6)
#define TIMER_3_INT_MATCH2 (1 << 7)
#define TIMER_3_INT_OVERFLOW (1 << 8)
#define TIMER_INT_ALL_MASK 0x1ff
static unsigned int tick_rate;
static void __iomem *base;
static u64 notrace gemini_read_sched_clock(void)
{
return readl(base + TIMER3_COUNT);
}
static int gemini_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
u32 cr;
/* Setup the match register */
cr = readl(base + TIMER1_COUNT);
writel(cr + cycles, base + TIMER1_MATCH1);
if (readl(base + TIMER1_COUNT) - cr > cycles)
return -ETIME;
return 0;
}
static int gemini_timer_shutdown(struct clock_event_device *evt)
{
u32 cr;
/*
* Disable also for oneshot: the set_next() call will arm the timer
* instead.
*/
/* Stop timer and interrupt. */
cr = readl(base + TIMER_CR);
cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
writel(cr, base + TIMER_CR);
/* Setup counter start from 0 */
writel(0, base + TIMER1_COUNT);
writel(0, base + TIMER1_LOAD);
/* enable interrupt */
cr = readl(base + TIMER_INTR_MASK);
cr &= ~(TIMER_1_INT_OVERFLOW | TIMER_1_INT_MATCH2);
cr |= TIMER_1_INT_MATCH1;
writel(cr, base + TIMER_INTR_MASK);
/* start the timer */
cr = readl(base + TIMER_CR);
cr |= TIMER_1_CR_ENABLE;
writel(cr, base + TIMER_CR);
return 0;
}
static int gemini_timer_set_periodic(struct clock_event_device *evt)
{
u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ);
u32 cr;
/* Stop timer and interrupt */
cr = readl(base + TIMER_CR);
cr &= ~(TIMER_1_CR_ENABLE | TIMER_1_CR_INT);
writel(cr, base + TIMER_CR);
/* Setup timer to fire at 1/HT intervals. */
cr = 0xffffffff - (period - 1);
writel(cr, base + TIMER1_COUNT);
writel(cr, base + TIMER1_LOAD);
/* enable interrupt on overflow */
cr = readl(base + TIMER_INTR_MASK);
cr &= ~(TIMER_1_INT_MATCH1 | TIMER_1_INT_MATCH2);
cr |= TIMER_1_INT_OVERFLOW;
writel(cr, base + TIMER_INTR_MASK);
/* Start the timer */
cr = readl(base + TIMER_CR);
cr |= TIMER_1_CR_ENABLE;
cr |= TIMER_1_CR_INT;
writel(cr, base + TIMER_CR);
return 0;
}
/* Use TIMER1 as clock event */
static struct clock_event_device gemini_clockevent = {
.name = "TIMER1",
/* Reasonably fast and accurate clock event */
.rating = 300,
.shift = 32,
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = gemini_timer_set_next_event,
.set_state_shutdown = gemini_timer_shutdown,
.set_state_periodic = gemini_timer_set_periodic,
.set_state_oneshot = gemini_timer_shutdown,
.tick_resume = gemini_timer_shutdown,
};
/*
* IRQ handler for the timer
*/
static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = &gemini_clockevent;
evt->event_handler(evt);
return IRQ_HANDLED;
}
static struct irqaction gemini_timer_irq = {
.name = "Gemini Timer Tick",
.flags = IRQF_TIMER,
.handler = gemini_timer_interrupt,
};
static int __init gemini_timer_of_init(struct device_node *np)
{
static struct regmap *map;
int irq;
int ret;
u32 val;
map = syscon_regmap_lookup_by_phandle(np, "syscon");
if (IS_ERR(map)) {
pr_err("Can't get regmap for syscon handle");
return -ENODEV;
}
ret = regmap_read(map, GLOBAL_STATUS, &val);
if (ret) {
pr_err("Can't read syscon status register");
return -ENXIO;
}
base = of_iomap(np, 0);
if (!base) {
pr_err("Can't remap registers");
return -ENXIO;
}
/* IRQ for timer 1 */
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0) {
pr_err("Can't parse IRQ");
return -EINVAL;
}
tick_rate = REG_TO_AHB_SPEED(val) * 1000000;
printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000);
tick_rate /= 6; /* APB bus run AHB*(1/6) */
switch (val & CPU_AHB_RATIO_MASK) {
case CPU_AHB_1_1:
printk(KERN_CONT "(1/1)\n");
break;
case CPU_AHB_3_2:
printk(KERN_CONT "(3/2)\n");
break;
case CPU_AHB_24_13:
printk(KERN_CONT "(24/13)\n");
break;
case CPU_AHB_2_1:
printk(KERN_CONT "(2/1)\n");
break;
}
/*
* Reset the interrupt mask and status
*/
writel(TIMER_INT_ALL_MASK, base + TIMER_INTR_MASK);
writel(0, base + TIMER_INTR_STATE);
writel(TIMER_DEFAULT_FLAGS, base + TIMER_CR);
/*
* Setup free-running clocksource timer (interrupts
* disabled.)
*/
writel(0, base + TIMER3_COUNT);
writel(0, base + TIMER3_LOAD);
writel(0, base + TIMER3_MATCH1);
writel(0, base + TIMER3_MATCH2);
clocksource_mmio_init(base + TIMER3_COUNT,
"gemini_clocksource", tick_rate,
300, 32, clocksource_mmio_readl_up);
sched_clock_register(gemini_read_sched_clock, 32, tick_rate);
/*
* Setup clockevent timer (interrupt-driven.)
*/
writel(0, base + TIMER1_COUNT);
writel(0, base + TIMER1_LOAD);
writel(0, base + TIMER1_MATCH1);
writel(0, base + TIMER1_MATCH2);
setup_irq(irq, &gemini_timer_irq);
gemini_clockevent.cpumask = cpumask_of(0);
clockevents_config_and_register(&gemini_clockevent, tick_rate,
1, 0xffffffff);
return 0;
}
CLOCKSOURCE_OF_DECLARE(nomadik_mtu, "cortina,gemini-timer",
gemini_timer_of_init);

4
fs/proc/base.c
View File

@ -2179,7 +2179,7 @@ static const struct file_operations proc_map_files_operations = {
.llseek = generic_file_llseek,
};
#ifdef CONFIG_CHECKPOINT_RESTORE
#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
struct timers_private {
struct pid *pid;
struct task_struct *task;
@ -2936,7 +2936,7 @@ static const struct pid_entry tgid_base_stuff[] = {
REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
REG("setgroups", S_IRUGO|S_IWUSR, proc_setgroups_operations),
#endif
#ifdef CONFIG_CHECKPOINT_RESTORE
#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
REG("timers", S_IRUGO, proc_timers_operations),
#endif
REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),

17
fs/timerfd.c
View File

@ -40,6 +40,7 @@ struct timerfd_ctx {
short unsigned settime_flags; /* to show in fdinfo */
struct rcu_head rcu;
struct list_head clist;
spinlock_t cancel_lock;
bool might_cancel;
};
@ -112,7 +113,7 @@ void timerfd_clock_was_set(void)
rcu_read_unlock();
}
static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
static void __timerfd_remove_cancel(struct timerfd_ctx *ctx)
{
if (ctx->might_cancel) {
ctx->might_cancel = false;
@ -122,6 +123,13 @@ static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
}
}
static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
{
spin_lock(&ctx->cancel_lock);
__timerfd_remove_cancel(ctx);
spin_unlock(&ctx->cancel_lock);
}
static bool timerfd_canceled(struct timerfd_ctx *ctx)
{
if (!ctx->might_cancel || ctx->moffs != KTIME_MAX)
@ -132,6 +140,7 @@ static bool timerfd_canceled(struct timerfd_ctx *ctx)
static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags)
{
spin_lock(&ctx->cancel_lock);
if ((ctx->clockid == CLOCK_REALTIME ||
ctx->clockid == CLOCK_REALTIME_ALARM) &&
(flags & TFD_TIMER_ABSTIME) && (flags & TFD_TIMER_CANCEL_ON_SET)) {
@ -141,9 +150,10 @@ static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags)
list_add_rcu(&ctx->clist, &cancel_list);
spin_unlock(&cancel_lock);
}
} else if (ctx->might_cancel) {
timerfd_remove_cancel(ctx);
} else {
__timerfd_remove_cancel(ctx);
}
spin_unlock(&ctx->cancel_lock);
}
static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx)
@ -400,6 +410,7 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags)
return -ENOMEM;
init_waitqueue_head(&ctx->wqh);
spin_lock_init(&ctx->cancel_lock);
ctx->clockid = clockid;
if (isalarm(ctx))

9
include/linux/clockchips.h
View File

@ -224,4 +224,13 @@ static inline void tick_setup_hrtimer_broadcast(void) { }
#endif /* !CONFIG_GENERIC_CLOCKEVENTS */
#define CLOCKEVENT_OF_DECLARE(name, compat, fn) \
OF_DECLARE_1_RET(clkevt, name, compat, fn)
#ifdef CONFIG_CLKEVT_PROBE
extern int clockevent_probe(void);
#els
static inline int clockevent_probe(void) { return 0; }
#endif
#endif /* _LINUX_CLOCKCHIPS_H */

7
include/linux/cpumask.h
View File

@ -649,11 +649,15 @@ static inline size_t cpumask_size(void)
* used. Please use this_cpu_cpumask_var_t in those cases. The direct use
* of this_cpu_ptr() or this_cpu_read() will lead to failures when the
* other type of cpumask_var_t implementation is configured.
*
* Please also note that __cpumask_var_read_mostly can be used to declare
* a cpumask_var_t variable itself (not its content) as read mostly.
*/
#ifdef CONFIG_CPUMASK_OFFSTACK
typedef struct cpumask *cpumask_var_t;
#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
#define this_cpu_cpumask_var_ptr(x) this_cpu_read(x)
#define __cpumask_var_read_mostly __read_mostly
bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node);
bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags);
@ -667,6 +671,7 @@ void free_bootmem_cpumask_var(cpumask_var_t mask);
typedef struct cpumask cpumask_var_t[1];
#define this_cpu_cpumask_var_ptr(x) this_cpu_ptr(x)
#define __cpumask_var_read_mostly
static inline bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
{

11
include/linux/delay.h
View File

@ -5,6 +5,17 @@
* Copyright (C) 1993 Linus Torvalds
*
* Delay routines, using a pre-computed "loops_per_jiffy" value.
*
* Please note that ndelay(), udelay() and mdelay() may return early for
* several reasons:
* 1. computed loops_per_jiffy too low (due to the time taken to
* execute the timer interrupt.)
* 2. cache behaviour affecting the time it takes to execute the
* loop function.
* 3. CPU clock rate changes.
*
* Please see this thread:
* http://lists.openwall.net/linux-kernel/2011/01/09/56
*/
#include <linux/kernel.h>

11
include/linux/hrtimer.h
View File

@ -88,12 +88,6 @@ enum hrtimer_restart {
* @base: pointer to the timer base (per cpu and per clock)
* @state: state information (See bit values above)
* @is_rel: Set if the timer was armed relative
* @start_pid: timer statistics field to store the pid of the task which
* started the timer
* @start_site: timer statistics field to store the site where the timer
* was started
* @start_comm: timer statistics field to store the name of the process which
* started the timer
*
* The hrtimer structure must be initialized by hrtimer_init()
*/
@ -104,11 +98,6 @@ struct hrtimer {
struct hrtimer_clock_base *base;
u8 state;
u8 is_rel;
#ifdef CONFIG_TIMER_STATS
int start_pid;
void *start_site;
char start_comm[16];
#endif
};
/**

40
include/linux/init_task.h
View File

@ -42,6 +42,27 @@ extern struct fs_struct init_fs;
#define INIT_PREV_CPUTIME(x)
#endif
#ifdef CONFIG_POSIX_TIMERS
#define INIT_POSIX_TIMERS(s) \
.posix_timers = LIST_HEAD_INIT(s.posix_timers),
#define INIT_CPU_TIMERS(s) \
.cpu_timers = { \
LIST_HEAD_INIT(s.cpu_timers[0]), \
LIST_HEAD_INIT(s.cpu_timers[1]), \
LIST_HEAD_INIT(s.cpu_timers[2]), \
},
#define INIT_CPUTIMER(s) \
.cputimer = { \
.cputime_atomic = INIT_CPUTIME_ATOMIC, \
.running = false, \
.checking_timer = false, \
},
#else
#define INIT_POSIX_TIMERS(s)
#define INIT_CPU_TIMERS(s)
#define INIT_CPUTIMER(s)
#endif
#define INIT_SIGNALS(sig) { \
.nr_threads = 1, \
.thread_head = LIST_HEAD_INIT(init_task.thread_node), \
@ -49,14 +70,10 @@ extern struct fs_struct init_fs;
.shared_pending = { \
.list = LIST_HEAD_INIT(sig.shared_pending.list), \
.signal = {{0}}}, \
.posix_timers = LIST_HEAD_INIT(sig.posix_timers), \
.cpu_timers = INIT_CPU_TIMERS(sig.cpu_timers), \
INIT_POSIX_TIMERS(sig) \
INIT_CPU_TIMERS(sig) \
.rlim = INIT_RLIMITS, \
.cputimer = { \
.cputime_atomic = INIT_CPUTIME_ATOMIC, \
.running = false, \
.checking_timer = false, \
}, \
INIT_CPUTIMER(sig) \
INIT_PREV_CPUTIME(sig) \
.cred_guard_mutex = \
__MUTEX_INITIALIZER(sig.cred_guard_mutex), \
@ -247,7 +264,7 @@ extern struct task_group root_task_group;
.blocked = {{0}}, \
.alloc_lock = __SPIN_LOCK_UNLOCKED(tsk.alloc_lock), \
.journal_info = NULL, \
.cpu_timers = INIT_CPU_TIMERS(tsk.cpu_timers), \
INIT_CPU_TIMERS(tsk) \
.pi_lock = __RAW_SPIN_LOCK_UNLOCKED(tsk.pi_lock), \
.timer_slack_ns = 50000, /* 50 usec default slack */ \
.pids = { \
@ -274,13 +291,6 @@ extern struct task_group root_task_group;
}
#define INIT_CPU_TIMERS(cpu_timers) \
{ \
LIST_HEAD_INIT(cpu_timers[0]), \
LIST_HEAD_INIT(cpu_timers[1]), \
LIST_HEAD_INIT(cpu_timers[2]), \
}
/* Attach to the init_task data structure for proper alignment */
#define __init_task_data __attribute__((__section__(".data..init_task")))

26
include/linux/math64.h
View File

@ -133,6 +133,16 @@ __iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
return ret;
}
#ifndef mul_u32_u32
/*
* Many a GCC version messes this up and generates a 64x64 mult :-(
*/
static inline u64 mul_u32_u32(u32 a, u32 b)
{
return (u64)a * b;
}
#endif
#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_INT128__)
#ifndef mul_u64_u32_shr
@ -160,9 +170,9 @@ static inline u64 mul_u64_u32_shr(u64 a, u32 mul, unsigned int shift)
al = a;
ah = a >> 32;
ret = ((u64)al * mul) >> shift;
ret = mul_u32_u32(al, mul) >> shift;
if (ah)
ret += ((u64)ah * mul) << (32 - shift);
ret += mul_u32_u32(ah, mul) << (32 - shift);
return ret;
}
@ -186,10 +196,10 @@ static inline u64 mul_u64_u64_shr(u64 a, u64 b, unsigned int shift)
a0.ll = a;
b0.ll = b;
rl.ll = (u64)a0.l.low * b0.l.low;
rm.ll = (u64)a0.l.low * b0.l.high;
rn.ll = (u64)a0.l.high * b0.l.low;
rh.ll = (u64)a0.l.high * b0.l.high;
rl.ll = mul_u32_u32(a0.l.low, b0.l.low);
rm.ll = mul_u32_u32(a0.l.low, b0.l.high);
rn.ll = mul_u32_u32(a0.l.high, b0.l.low);
rh.ll = mul_u32_u32(a0.l.high, b0.l.high);
/*
* Each of these lines computes a 64-bit intermediate result into "c",
@ -229,8 +239,8 @@ static inline u64 mul_u64_u32_div(u64 a, u32 mul, u32 divisor)
} u, rl, rh;
u.ll = a;
rl.ll = (u64)u.l.low * mul;
rh.ll = (u64)u.l.high * mul + rl.l.high;
rl.ll = mul_u32_u32(u.l.low, mul);
rh.ll = mul_u32_u32(u.l.high, mul) + rl.l.high;
/* Bits 32-63 of the result will be in rh.l.low. */
rl.l.high = do_div(rh.ll, divisor);

13
include/linux/sched.h
View File

@ -734,13 +734,14 @@ struct signal_struct {
unsigned int is_child_subreaper:1;
unsigned int has_child_subreaper:1;
#ifdef CONFIG_POSIX_TIMERS
/* POSIX.1b Interval Timers */
int posix_timer_id;
struct list_head posix_timers;
/* ITIMER_REAL timer for the process */
struct hrtimer real_timer;
struct pid *leader_pid;
ktime_t it_real_incr;
/*
@ -759,12 +760,16 @@ struct signal_struct {
/* Earliest-expiration cache. */
struct task_cputime cputime_expires;
struct list_head cpu_timers[3];
#endif
struct pid *leader_pid;
#ifdef CONFIG_NO_HZ_FULL
atomic_t tick_dep_mask;
#endif
struct list_head cpu_timers[3];
struct pid *tty_old_pgrp;
/* boolean value for session group leader */
@ -1691,8 +1696,10 @@ struct task_struct {
/* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
unsigned long min_flt, maj_flt;
#ifdef CONFIG_POSIX_TIMERS
struct task_cputime cputime_expires;
struct list_head cpu_timers[3];
#endif
/* process credentials */
const struct cred __rcu *ptracer_cred; /* Tracer's credentials at attach */

45
include/linux/timer.h
View File

@ -20,11 +20,6 @@ struct timer_list {
unsigned long data;
u32 flags;
#ifdef CONFIG_TIMER_STATS
int start_pid;
void *start_site;
char start_comm[16];
#endif
#ifdef CONFIG_LOCKDEP
struct lockdep_map lockdep_map;
#endif
@ -197,46 +192,6 @@ extern int mod_timer_pending(struct timer_list *timer, unsigned long expires);
*/
#define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
/*
* Timer-statistics info:
*/
#ifdef CONFIG_TIMER_STATS
extern int timer_stats_active;
extern void init_timer_stats(void);
extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
void *timerf, char *comm, u32 flags);
extern void __timer_stats_timer_set_start_info(struct timer_list *timer,
void *addr);
static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
{
if (likely(!timer_stats_active))
return;
__timer_stats_timer_set_start_info(timer, __builtin_return_address(0));
}
static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
{
timer->start_site = NULL;
}
#else
static inline void init_timer_stats(void)
{
}
static inline void timer_stats_timer_set_start_info(struct timer_list *timer)
{
}
static inline void timer_stats_timer_clear_start_info(struct timer_list *timer)
{
}
#endif
extern void add_timer(struct timer_list *timer);
extern int try_to_del_timer_sync(struct timer_list *timer);

10
kernel/fork.c
View File

@ -1304,6 +1304,7 @@ void __cleanup_sighand(struct sighand_struct *sighand)
}
}
#ifdef CONFIG_POSIX_TIMERS
/*
* Initialize POSIX timer handling for a thread group.
*/
@ -1322,6 +1323,9 @@ static void posix_cpu_timers_init_group(struct signal_struct *sig)
INIT_LIST_HEAD(&sig->cpu_timers[1]);
INIT_LIST_HEAD(&sig->cpu_timers[2]);
}
#else
static inline void posix_cpu_timers_init_group(struct signal_struct *sig) { }
#endif
static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
{
@ -1346,11 +1350,11 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
init_waitqueue_head(&sig->wait_chldexit);
sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
seqlock_init(&sig->stats_lock);
prev_cputime_init(&sig->prev_cputime);
#ifdef CONFIG_POSIX_TIMERS
INIT_LIST_HEAD(&sig->posix_timers);
hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
sig->real_timer.function = it_real_fn;
#endif
@ -1425,6 +1429,7 @@ static void rt_mutex_init_task(struct task_struct *p)
#endif
}
#ifdef CONFIG_POSIX_TIMERS
/*
* Initialize POSIX timer handling for a single task.
*/
@ -1437,6 +1442,9 @@ static void posix_cpu_timers_init(struct task_struct *tsk)
INIT_LIST_HEAD(&tsk->cpu_timers[1]);
INIT_LIST_HEAD(&tsk->cpu_timers[2]);
}
#else
static inline void posix_cpu_timers_init(struct task_struct *tsk) { }
#endif
static inline void
init_task_pid(struct task_struct *task, enum pid_type type, struct pid *pid)

1
kernel/kthread.c
View File

@ -850,7 +850,6 @@ void __kthread_queue_delayed_work(struct kthread_worker *worker,
list_add(&work->node, &worker->delayed_work_list);
work->worker = worker;
timer_stats_timer_set_start_info(&dwork->timer);
timer->expires = jiffies + delay;
add_timer(timer);
}

4
kernel/sched/rt.c
View File

@ -2246,6 +2246,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
}
}
#ifdef CONFIG_POSIX_TIMERS
static void watchdog(struct rq *rq, struct task_struct *p)
{
unsigned long soft, hard;
@ -2267,6 +2268,9 @@ static void watchdog(struct rq *rq, struct task_struct *p)
p->cputime_expires.sched_exp = p->se.sum_exec_runtime;
}
}
#else
static inline void watchdog(struct rq *rq, struct task_struct *p) { }
#endif
static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
{

32
kernel/sched/stats.h
View File

@ -172,18 +172,19 @@ sched_info_switch(struct rq *rq,
*/
/**
* cputimer_running - return true if cputimer is running
* get_running_cputimer - return &tsk->signal->cputimer if cputimer is running
*
* @tsk: Pointer to target task.
*/
static inline bool cputimer_running(struct task_struct *tsk)
#ifdef CONFIG_POSIX_TIMERS
static inline
struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
/* Check if cputimer isn't running. This is accessed without locking. */
if (!READ_ONCE(cputimer->running))
return false;
return NULL;
/*
* After we flush the task's sum_exec_runtime to sig->sum_sched_runtime
@ -200,10 +201,17 @@ static inline bool cputimer_running(struct task_struct *tsk)
* clock delta is behind the expiring timer value.
*/
if (unlikely(!tsk->sighand))
return false;
return NULL;
return true;
return cputimer;
}
#else
static inline
struct thread_group_cputimer *get_running_cputimer(struct task_struct *tsk)
{
return NULL;
}
#endif
/**
* account_group_user_time - Maintain utime for a thread group.
@ -218,9 +226,9 @@ static inline bool cputimer_running(struct task_struct *tsk)
static inline void account_group_user_time(struct task_struct *tsk,
cputime_t cputime)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
if (!cputimer_running(tsk))
if (!cputimer)
return;
atomic64_add(cputime, &cputimer->cputime_atomic.utime);
@ -239,9 +247,9 @@ static inline void account_group_user_time(struct task_struct *tsk,
static inline void account_group_system_time(struct task_struct *tsk,
cputime_t cputime)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
if (!cputimer_running(tsk))
if (!cputimer)
return;
atomic64_add(cputime, &cputimer->cputime_atomic.stime);
@ -260,9 +268,9 @@ static inline void account_group_system_time(struct task_struct *tsk,
static inline void account_group_exec_runtime(struct task_struct *tsk,
unsigned long long ns)
{
struct thread_group_cputimer *cputimer = &tsk->signal->cputimer;
struct thread_group_cputimer *cputimer = get_running_cputimer(tsk);
if (!cputimer_running(tsk))
if (!cputimer)
return;
atomic64_add(ns, &cputimer->cputime_atomic.sum_exec_runtime);

1
kernel/time/Makefile
View File

@ -15,6 +15,5 @@ ifeq ($(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST),y)
endif
obj-$(CONFIG_GENERIC_SCHED_CLOCK) += sched_clock.o
obj-$(CONFIG_TICK_ONESHOT) += tick-oneshot.o tick-sched.o
obj-$(CONFIG_TIMER_STATS) += timer_stats.o
obj-$(CONFIG_DEBUG_FS) += timekeeping_debug.o
obj-$(CONFIG_TEST_UDELAY) += test_udelay.o

58
kernel/time/hrtimer.c
View File

@ -94,17 +94,15 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
};
static const int hrtimer_clock_to_base_table[MAX_CLOCKS] = {
/* Make sure we catch unsupported clockids */
[0 ... MAX_CLOCKS - 1] = HRTIMER_MAX_CLOCK_BASES,
[CLOCK_REALTIME] = HRTIMER_BASE_REALTIME,
[CLOCK_MONOTONIC] = HRTIMER_BASE_MONOTONIC,
[CLOCK_BOOTTIME] = HRTIMER_BASE_BOOTTIME,
[CLOCK_TAI] = HRTIMER_BASE_TAI,
};
static inline int hrtimer_clockid_to_base(clockid_t clock_id)
{
return hrtimer_clock_to_base_table[clock_id];
}
/*
* Functions and macros which are different for UP/SMP systems are kept in a
* single place
@ -766,34 +764,6 @@ void hrtimers_resume(void)
clock_was_set_delayed();
}
static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
{
#ifdef CONFIG_TIMER_STATS
if (timer->start_site)
return;
timer->start_site = __builtin_return_address(0);
memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
timer->start_pid = current->pid;
#endif
}
static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
{
#ifdef CONFIG_TIMER_STATS
timer->start_site = NULL;
#endif
}
static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
{
#ifdef CONFIG_TIMER_STATS
if (likely(!timer_stats_active))
return;
timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
timer->function, timer->start_comm, 0);
#endif
}
/*
* Counterpart to lock_hrtimer_base above:
*/
@ -932,7 +902,6 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base, bool rest
* rare case and less expensive than a smp call.
*/
debug_deactivate(timer);
timer_stats_hrtimer_clear_start_info(timer);
reprogram = base->cpu_base == this_cpu_ptr(&hrtimer_bases);
if (!restart)
@ -990,8 +959,6 @@ void hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
/* Switch the timer base, if necessary: */
new_base = switch_hrtimer_base(timer, base, mode & HRTIMER_MODE_PINNED);
timer_stats_hrtimer_set_start_info(timer);
leftmost = enqueue_hrtimer(timer, new_base);
if (!leftmost)
goto unlock;
@ -1112,6 +1079,18 @@ u64 hrtimer_get_next_event(void)
}
#endif
static inline int hrtimer_clockid_to_base(clockid_t clock_id)
{
if (likely(clock_id < MAX_CLOCKS)) {
int base = hrtimer_clock_to_base_table[clock_id];
if (likely(base != HRTIMER_MAX_CLOCK_BASES))
return base;
}
WARN(1, "Invalid clockid %d. Using MONOTONIC\n", clock_id);
return HRTIMER_BASE_MONOTONIC;
}
static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
enum hrtimer_mode mode)
{
@ -1128,12 +1107,6 @@ static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
base = hrtimer_clockid_to_base(clock_id);
timer->base = &cpu_base->clock_base[base];
timerqueue_init(&timer->node);
#ifdef CONFIG_TIMER_STATS
timer->start_site = NULL;
timer->start_pid = -1;
memset(timer->start_comm, 0, TASK_COMM_LEN);
#endif
}
/**
@ -1217,7 +1190,6 @@ static void __run_hrtimer(struct hrtimer_cpu_base *cpu_base,
raw_write_seqcount_barrier(&cpu_base->seq);
__remove_hrtimer(timer, base, HRTIMER_STATE_INACTIVE, 0);
timer_stats_account_hrtimer(timer);
fn = timer->function;
/*

15
kernel/time/tick-broadcast.c
View File

@ -29,12 +29,13 @@
*/
static struct tick_device tick_broadcast_device;
static cpumask_var_t tick_broadcast_mask;
static cpumask_var_t tick_broadcast_on;
static cpumask_var_t tmpmask;
static DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
static cpumask_var_t tick_broadcast_mask __cpumask_var_read_mostly;
static cpumask_var_t tick_broadcast_on __cpumask_var_read_mostly;
static cpumask_var_t tmpmask __cpumask_var_read_mostly;
static int tick_broadcast_forced;
static __cacheline_aligned_in_smp DEFINE_RAW_SPINLOCK(tick_broadcast_lock);
#ifdef CONFIG_TICK_ONESHOT
static void tick_broadcast_clear_oneshot(int cpu);
static void tick_resume_broadcast_oneshot(struct clock_event_device *bc);
@ -516,9 +517,9 @@ void tick_resume_broadcast(void)
#ifdef CONFIG_TICK_ONESHOT
static cpumask_var_t tick_broadcast_oneshot_mask;
static cpumask_var_t tick_broadcast_pending_mask;
static cpumask_var_t tick_broadcast_force_mask;
static cpumask_var_t tick_broadcast_oneshot_mask __cpumask_var_read_mostly;
static cpumask_var_t tick_broadcast_pending_mask __cpumask_var_read_mostly;
static cpumask_var_t tick_broadcast_force_mask __cpumask_var_read_mostly;
/*
* Exposed for debugging: see timer_list.c

39
kernel/time/timekeeping.c
View File

@ -1275,27 +1275,8 @@ error: /* even if we error out, we forwarded the time, so call update */
}
EXPORT_SYMBOL(timekeeping_inject_offset);
/**
* timekeeping_get_tai_offset - Returns current TAI offset from UTC
*
*/
s32 timekeeping_get_tai_offset(void)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned int seq;
s32 ret;
do {
seq = read_seqcount_begin(&tk_core.seq);
ret = tk->tai_offset;
} while (read_seqcount_retry(&tk_core.seq, seq));
return ret;
}
/**
* __timekeeping_set_tai_offset - Lock free worker function
* __timekeeping_set_tai_offset - Sets the TAI offset from UTC and monotonic
*
*/
static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
@ -1304,24 +1285,6 @@ static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
tk->offs_tai = ktime_add(tk->offs_real, ktime_set(tai_offset, 0));
}
/**
* timekeeping_set_tai_offset - Sets the current TAI offset from UTC
*
*/
void timekeeping_set_tai_offset(s32 tai_offset)
{
struct timekeeper *tk = &tk_core.timekeeper;
unsigned long flags;
raw_spin_lock_irqsave(&timekeeper_lock, flags);
write_seqcount_begin(&tk_core.seq);
__timekeeping_set_tai_offset(tk, tai_offset);
timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
write_seqcount_end(&tk_core.seq);
raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
clock_was_set();
}
/**
* change_clocksource - Swaps clocksources if a new one is available
*

2
kernel/time/timekeeping.h
View File

@ -11,8 +11,6 @@ extern ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq,
extern int timekeeping_valid_for_hres(void);
extern u64 timekeeping_max_deferment(void);
extern int timekeeping_inject_offset(struct timespec *ts);
extern s32 timekeeping_get_tai_offset(void);
extern void timekeeping_set_tai_offset(s32 tai_offset);
extern int timekeeping_suspend(void);
extern void timekeeping_resume(void);

48
kernel/time/timer.c
View File

@ -571,38 +571,6 @@ internal_add_timer(struct timer_base *base, struct timer_list *timer)
trigger_dyntick_cpu(base, timer);
}
#ifdef CONFIG_TIMER_STATS
void __timer_stats_timer_set_start_info(struct timer_list *timer, void *addr)
{
if (timer->start_site)
return;
timer->start_site = addr;
memcpy(timer->start_comm, current->comm, TASK_COMM_LEN);
timer->start_pid = current->pid;
}
static void timer_stats_account_timer(struct timer_list *timer)
{
void *site;
/*
* start_site can be concurrently reset by
* timer_stats_timer_clear_start_info()
*/
site = READ_ONCE(timer->start_site);
if (likely(!site))
return;
timer_stats_update_stats(timer, timer->start_pid, site,
timer->function, timer->start_comm,
timer->flags);
}
#else
static void timer_stats_account_timer(struct timer_list *timer) {}
#endif
#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
static struct debug_obj_descr timer_debug_descr;
@ -789,11 +757,6 @@ static void do_init_timer(struct timer_list *timer, unsigned int flags,
{
timer->entry.pprev = NULL;
timer->flags = flags | raw_smp_processor_id();
#ifdef CONFIG_TIMER_STATS
timer->start_site = NULL;
timer->start_pid = -1;
memset(timer->start_comm, 0, TASK_COMM_LEN);
#endif
lockdep_init_map(&timer->lockdep_map, name, key, 0);
}
@ -1001,8 +964,6 @@ __mod_timer(struct timer_list *timer, unsigned long expires, bool pending_only)
base = lock_timer_base(timer, &flags);
}
timer_stats_timer_set_start_info(timer);
ret = detach_if_pending(timer, base, false);
if (!ret && pending_only)
goto out_unlock;
@ -1130,7 +1091,6 @@ void add_timer_on(struct timer_list *timer, int cpu)
struct timer_base *new_base, *base;
unsigned long flags;
timer_stats_timer_set_start_info(timer);
BUG_ON(timer_pending(timer) || !timer->function);
new_base = get_timer_cpu_base(timer->flags, cpu);
@ -1176,7 +1136,6 @@ int del_timer(struct timer_list *timer)
debug_assert_init(timer);
timer_stats_timer_clear_start_info(timer);
if (timer_pending(timer)) {
base = lock_timer_base(timer, &flags);
ret = detach_if_pending(timer, base, true);
@ -1204,10 +1163,9 @@ int try_to_del_timer_sync(struct timer_list *timer)
base = lock_timer_base(timer, &flags);
if (base->running_timer != timer) {
timer_stats_timer_clear_start_info(timer);
if (base->running_timer != timer)
ret = detach_if_pending(timer, base, true);
}
spin_unlock_irqrestore(&base->lock, flags);
return ret;
@ -1331,7 +1289,6 @@ static void expire_timers(struct timer_base *base, struct hlist_head *head)
unsigned long data;
timer = hlist_entry(head->first, struct timer_list, entry);
timer_stats_account_timer(timer);
base->running_timer = timer;
detach_timer(timer, true);
@ -1868,7 +1825,6 @@ static void __init init_timer_cpus(void)
void __init init_timers(void)
{
init_timer_cpus();
init_timer_stats();
open_softirq(TIMER_SOFTIRQ, run_timer_softirq);
}

12
kernel/time/timer_list.c
View File

@ -62,21 +62,11 @@ static void
print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
int idx, u64 now)
{
#ifdef CONFIG_TIMER_STATS
char tmp[TASK_COMM_LEN + 1];
#endif
SEQ_printf(m, " #%d: ", idx);
print_name_offset(m, taddr);
SEQ_printf(m, ", ");
print_name_offset(m, timer->function);
SEQ_printf(m, ", S:%02x", timer->state);
#ifdef CONFIG_TIMER_STATS
SEQ_printf(m, ", ");
print_name_offset(m, timer->start_site);
memcpy(tmp, timer->start_comm, TASK_COMM_LEN);
tmp[TASK_COMM_LEN] = 0;
SEQ_printf(m, ", %s/%d", tmp, timer->start_pid);
#endif
SEQ_printf(m, "\n");
SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n",
(unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)),
@ -127,7 +117,7 @@ print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now)
SEQ_printf(m, " .base: %pK\n", base);
SEQ_printf(m, " .index: %d\n", base->index);
SEQ_printf(m, " .resolution: %u nsecs\n", (unsigned) hrtimer_resolution);
SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution);
SEQ_printf(m, " .get_time: ");
print_name_offset(m, base->get_time);

425
kernel/time/timer_stats.c
View File

@ -1,425 +0,0 @@
/*
* kernel/time/timer_stats.c
*
* Collect timer usage statistics.
*
* Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
* Copyright(C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
*
* timer_stats is based on timer_top, a similar functionality which was part of
* Con Kolivas dyntick patch set. It was developed by Daniel Petrini at the
* Instituto Nokia de Tecnologia - INdT - Manaus. timer_top's design was based
* on dynamic allocation of the statistics entries and linear search based
* lookup combined with a global lock, rather than the static array, hash
* and per-CPU locking which is used by timer_stats. It was written for the
* pre hrtimer kernel code and therefore did not take hrtimers into account.
* Nevertheless it provided the base for the timer_stats implementation and
* was a helpful source of inspiration. Kudos to Daniel and the Nokia folks
* for this effort.
*
* timer_top.c is
* Copyright (C) 2005 Instituto Nokia de Tecnologia - INdT - Manaus
* Written by Daniel Petrini <d.pensator@gmail.com>
* timer_top.c was released under the GNU General Public License version 2
*
* We export the addresses and counting of timer functions being called,
* the pid and cmdline from the owner process if applicable.
*
* Start/stop data collection:
* # echo [1|0] >/proc/timer_stats
*
* Display the information collected so far:
* # cat /proc/timer_stats
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/proc_fs.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
/*
* This is our basic unit of interest: a timer expiry event identified
* by the timer, its start/expire functions and the PID of the task that
* started the timer. We count the number of times an event happens:
*/
struct entry {
/*
* Hash list:
*/
struct entry *next;
/*
* Hash keys:
*/
void *timer;
void *start_func;
void *expire_func;
pid_t pid;
/*
* Number of timeout events:
*/
unsigned long count;
u32 flags;
/*
* We save the command-line string to preserve
* this information past task exit:
*/
char comm[TASK_COMM_LEN + 1];
} ____cacheline_aligned_in_smp;
/*
* Spinlock protecting the tables - not taken during lookup:
*/
static DEFINE_RAW_SPINLOCK(table_lock);
/*
* Per-CPU lookup locks for fast hash lookup:
*/
static DEFINE_PER_CPU(raw_spinlock_t, tstats_lookup_lock);
/*
* Mutex to serialize state changes with show-stats activities:
*/
static DEFINE_MUTEX(show_mutex);
/*
* Collection status, active/inactive:
*/
int __read_mostly timer_stats_active;
/*
* Beginning/end timestamps of measurement:
*/
static ktime_t time_start, time_stop;
/*
* tstat entry structs only get allocated while collection is
* active and never freed during that time - this simplifies
* things quite a bit.
*
* They get freed when a new collection period is started.
*/
#define MAX_ENTRIES_BITS 10
#define MAX_ENTRIES (1UL << MAX_ENTRIES_BITS)
static unsigned long nr_entries;
static struct entry entries[MAX_ENTRIES];
static atomic_t overflow_count;
/*
* The entries are in a hash-table, for fast lookup:
*/
#define TSTAT_HASH_BITS (MAX_ENTRIES_BITS - 1)
#define TSTAT_HASH_SIZE (1UL << TSTAT_HASH_BITS)
#define TSTAT_HASH_MASK (TSTAT_HASH_SIZE - 1)
#define __tstat_hashfn(entry) \
(((unsigned long)(entry)->timer ^ \
(unsigned long)(entry)->start_func ^ \
(unsigned long)(entry)->expire_func ^ \
(unsigned long)(entry)->pid ) & TSTAT_HASH_MASK)
#define tstat_hashentry(entry) (tstat_hash_table + __tstat_hashfn(entry))
static struct entry *tstat_hash_table[TSTAT_HASH_SIZE] __read_mostly;
static void reset_entries(void)
{
nr_entries = 0;
memset(entries, 0, sizeof(entries));
memset(tstat_hash_table, 0, sizeof(tstat_hash_table));
atomic_set(&overflow_count, 0);
}
static struct entry *alloc_entry(void)
{
if (nr_entries >= MAX_ENTRIES)
return NULL;
return entries + nr_entries++;
}
static int match_entries(struct entry *entry1, struct entry *entry2)
{
return entry1->timer == entry2->timer &&
entry1->start_func == entry2->start_func &&
entry1->expire_func == entry2->expire_func &&
entry1->pid == entry2->pid;
}
/*
* Look up whether an entry matching this item is present
* in the hash already. Must be called with irqs off and the
* lookup lock held:
*/
static struct entry *tstat_lookup(struct entry *entry, char *comm)
{
struct entry **head, *curr, *prev;
head = tstat_hashentry(entry);
curr = *head;
/*
* The fastpath is when the entry is already hashed,
* we do this with the lookup lock held, but with the
* table lock not held:
*/
while (curr) {
if (match_entries(curr, entry))
return curr;
curr = curr->next;
}
/*
* Slowpath: allocate, set up and link a new hash entry:
*/
prev = NULL;
curr = *head;
raw_spin_lock(&table_lock);
/*
* Make sure we have not raced with another CPU:
*/
while (curr) {
if (match_entries(curr, entry))
goto out_unlock;
prev = curr;
curr = curr->next;
}
curr = alloc_entry();
if (curr) {
*curr = *entry;
curr->count = 0;
curr->next = NULL;
memcpy(curr->comm, comm, TASK_COMM_LEN);
smp_mb(); /* Ensure that curr is initialized before insert */
if (prev)
prev->next = curr;
else
*head = curr;
}
out_unlock:
raw_spin_unlock(&table_lock);
return curr;
}
/**
* timer_stats_update_stats - Update the statistics for a timer.
* @timer: pointer to either a timer_list or a hrtimer
* @pid: the pid of the task which set up the timer
* @startf: pointer to the function which did the timer setup
* @timerf: pointer to the timer callback function of the timer
* @comm: name of the process which set up the timer
* @tflags: The flags field of the timer
*
* When the timer is already registered, then the event counter is
* incremented. Otherwise the timer is registered in a free slot.
*/
void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
void *timerf, char *comm, u32 tflags)
{
/*
* It doesn't matter which lock we take:
*/
raw_spinlock_t *lock;
struct entry *entry, input;
unsigned long flags;
if (likely(!timer_stats_active))
return;
lock = &per_cpu(tstats_lookup_lock, raw_smp_processor_id());
input.timer = timer;
input.start_func = startf;
input.expire_func = timerf;
input.pid = pid;
input.flags = tflags;
raw_spin_lock_irqsave(lock, flags);
if (!timer_stats_active)
goto out_unlock;
entry = tstat_lookup(&input, comm);
if (likely(entry))
entry->count++;
else
atomic_inc(&overflow_count);
out_unlock:
raw_spin_unlock_irqrestore(lock, flags);
}
static void print_name_offset(struct seq_file *m, unsigned long addr)
{
char symname[KSYM_NAME_LEN];
if (lookup_symbol_name(addr, symname) < 0)
seq_printf(m, "<%p>", (void *)addr);
else
seq_printf(m, "%s", symname);
}
static int tstats_show(struct seq_file *m, void *v)
{
struct timespec64 period;
struct entry *entry;
unsigned long ms;
long events = 0;
ktime_t time;
int i;
mutex_lock(&show_mutex);
/*
* If still active then calculate up to now:
*/
if (timer_stats_active)
time_stop = ktime_get();
time = ktime_sub(time_stop, time_start);
period = ktime_to_timespec64(time);
ms = period.tv_nsec / 1000000;
seq_puts(m, "Timer Stats Version: v0.3\n");
seq_printf(m, "Sample period: %ld.%03ld s\n", (long)period.tv_sec, ms);
if (atomic_read(&overflow_count))
seq_printf(m, "Overflow: %d entries\n", atomic_read(&overflow_count));
seq_printf(m, "Collection: %s\n", timer_stats_active ? "active" : "inactive");
for (i = 0; i < nr_entries; i++) {
entry = entries + i;
if (entry->flags & TIMER_DEFERRABLE) {
seq_printf(m, "%4luD, %5d %-16s ",
entry->count, entry->pid, entry->comm);
} else {
seq_printf(m, " %4lu, %5d %-16s ",
entry->count, entry->pid, entry->comm);
}
print_name_offset(m, (unsigned long)entry->start_func);
seq_puts(m, " (");
print_name_offset(m, (unsigned long)entry->expire_func);
seq_puts(m, ")\n");
events += entry->count;
}
ms += period.tv_sec * 1000;
if (!ms)
ms = 1;
if (events && period.tv_sec)
seq_printf(m, "%ld total events, %ld.%03ld events/sec\n",
events, events * 1000 / ms,
(events * 1000000 / ms) % 1000);
else
seq_printf(m, "%ld total events\n", events);
mutex_unlock(&show_mutex);
return 0;
}
/*
* After a state change, make sure all concurrent lookup/update
* activities have stopped:
*/
static void sync_access(void)
{
unsigned long flags;
int cpu;
for_each_online_cpu(cpu) {
raw_spinlock_t *lock = &per_cpu(tstats_lookup_lock, cpu);
raw_spin_lock_irqsave(lock, flags);
/* nothing */
raw_spin_unlock_irqrestore(lock, flags);
}
}
static ssize_t tstats_write(struct file *file, const char __user *buf,
size_t count, loff_t *offs)
{
char ctl[2];
if (count != 2 || *offs)
return -EINVAL;
if (copy_from_user(ctl, buf, count))
return -EFAULT;
mutex_lock(&show_mutex);
switch (ctl[0]) {
case '0':
if (timer_stats_active) {
timer_stats_active = 0;
time_stop = ktime_get();
sync_access();
}
break;
case '1':
if (!timer_stats_active) {
reset_entries();
time_start = ktime_get();
smp_mb();
timer_stats_active = 1;
}
break;
default:
count = -EINVAL;
}
mutex_unlock(&show_mutex);
return count;
}
static int tstats_open(struct inode *inode, struct file *filp)
{
return single_open(filp, tstats_show, NULL);
}
static const struct file_operations tstats_fops = {
.open = tstats_open,
.read = seq_read,
.write = tstats_write,
.llseek = seq_lseek,
.release = single_release,
};
void __init init_timer_stats(void)
{
int cpu;
for_each_possible_cpu(cpu)
raw_spin_lock_init(&per_cpu(tstats_lookup_lock, cpu));
}
static int __init init_tstats_procfs(void)
{
struct proc_dir_entry *pe;
pe = proc_create("timer_stats", 0644, NULL, &tstats_fops);
if (!pe)
return -ENOMEM;
return 0;
}
__initcall(init_tstats_procfs);

2
kernel/workqueue.c
View File

@ -1523,8 +1523,6 @@ static void __queue_delayed_work(int cpu, struct workqueue_struct *wq,
return;
}
timer_stats_timer_set_start_info(&dwork->timer);
dwork->wq = wq;
dwork->cpu = cpu;
timer->expires = jiffies + delay;

14
lib/Kconfig.debug
View File

@ -980,20 +980,6 @@ config DEBUG_TIMEKEEPING
If unsure, say N.
config TIMER_STATS
bool "Collect kernel timers statistics"
depends on DEBUG_KERNEL && PROC_FS
help
If you say Y here, additional code will be inserted into the
timer routines to collect statistics about kernel timers being
reprogrammed. The statistics can be read from /proc/timer_stats.
The statistics collection is started by writing 1 to /proc/timer_stats,
writing 0 stops it. This feature is useful to collect information
about timer usage patterns in kernel and userspace. This feature
is lightweight if enabled in the kernel config but not activated
(it defaults to deactivated on bootup and will only be activated
if some application like powertop activates it explicitly).
config DEBUG_PREEMPT
bool "Debug preemptible kernel"
depends on DEBUG_KERNEL && PREEMPT && TRACE_IRQFLAGS_SUPPORT

3
lib/timerqueue.c
View File

@ -80,8 +80,7 @@ bool timerqueue_del(struct timerqueue_head *head, struct timerqueue_node *node)
if (head->next == node) {
struct rb_node *rbn = rb_next(&node->node);
head->next = rbn ?
rb_entry(rbn, struct timerqueue_node, node) : NULL;
head->next = rb_entry_safe(rbn, struct timerqueue_node, node);
}
rb_erase(&node->node, &head->head);
RB_CLEAR_NODE(&node->node);