linux-stable.git/drivers/clocksource, branch v6.1.136

clocksource/drivers/stm32-lptimer: Use wakeup capable instead of init wakeup

2025-04-25T08:43:39+00:00

commit 96bf4b89a6ab22426ad83ef76e66c72a5a8daca0 upstream.

"wakeup-source" property describes a device which has wakeup capability
but should not force this device as a wakeup source.

Fixes: 48b41c5e2de6 ("clocksource: Add Low Power STM32 timers driver")
Cc: stable@vger.kernel.org
Signed-off-by: Alexandre Torgue 
Signed-off-by: Fabrice Gasnier 
Rule: add
Link: https://lore.kernel.org/stable/20250306083407.2374894-1-fabrice.gasnier%40foss.st.com
Link: https://lore.kernel.org/r/20250306102501.2980153-1-fabrice.gasnier@foss.st.com
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clockevents/drivers/i8253: Fix stop sequence for timer 0

2025-03-28T20:58:48+00:00

commit 531b2ca0a940ac9db03f246c8b77c4201de72b00 upstream.

According to the data sheet, writing the MODE register should stop the
counter (and thus the interrupts). This appears to work on real hardware,
at least modern Intel and AMD systems. It should also work on Hyper-V.

However, on some buggy virtual machines the mode change doesn't have any
effect until the counter is subsequently loaded (or perhaps when the IRQ
next fires).

So, set MODE 0 and then load the counter, to ensure that those buggy VMs
do the right thing and the interrupts stop. And then write MODE 0 *again*
to stop the counter on compliant implementations too.

Apparently, Hyper-V keeps firing the IRQ *repeatedly* even in mode zero
when it should only happen once, but the second MODE write stops that too.

Userspace test program (mostly written by tglx):
=====
 #include 
 #include 
 #include 
 #include 
 #include 

static __always_inline void __out##bwl(type value, uint16_t port)	\
{									\
	asm volatile("out" #bwl " %" #bw "0, %w1"			\
		     : : "a"(value), "Nd"(port));			\
}									\
									\
static __always_inline type __in##bwl(uint16_t port)			\
{									\
	type value;							\
	asm volatile("in" #bwl " %w1, %" #bw "0"			\
		     : "=a"(value) : "Nd"(port));			\
	return value;							\
}

BUILDIO(b, b, uint8_t)

 #define inb __inb
 #define outb __outb

 #define PIT_MODE	0x43
 #define PIT_CH0	0x40
 #define PIT_CH2	0x42

static int is8254;

static void dump_pit(void)
{
	if (is8254) {
		// Latch and output counter and status
		outb(0xC2, PIT_MODE);
		printf("%02x %02x %02x\n", inb(PIT_CH0), inb(PIT_CH0), inb(PIT_CH0));
	} else {
		// Latch and output counter
		outb(0x0, PIT_MODE);
		printf("%02x %02x\n", inb(PIT_CH0), inb(PIT_CH0));
	}
}

int main(int argc, char* argv[])
{
	int nr_counts = 2;

	if (argc > 1)
		nr_counts = atoi(argv[1]);

	if (argc > 2)
		is8254 = 1;

	if (ioperm(0x40, 4, 1) != 0)
		return 1;

	dump_pit();

	printf("Set oneshot\n");
	outb(0x38, PIT_MODE);
	outb(0x00, PIT_CH0);
	outb(0x0F, PIT_CH0);

	dump_pit();
	usleep(1000);
	dump_pit();

	printf("Set periodic\n");
	outb(0x34, PIT_MODE);
	outb(0x00, PIT_CH0);
	outb(0x0F, PIT_CH0);

	dump_pit();
	usleep(1000);
	dump_pit();
	dump_pit();
	usleep(100000);
	dump_pit();
	usleep(100000);
	dump_pit();

	printf("Set stop (%d counter writes)\n", nr_counts);
	outb(0x30, PIT_MODE);
	while (nr_counts--)
		outb(0xFF, PIT_CH0);

	dump_pit();
	usleep(100000);
	dump_pit();
	usleep(100000);
	dump_pit();

	printf("Set MODE 0\n");
	outb(0x30, PIT_MODE);

	dump_pit();
	usleep(100000);
	dump_pit();
	usleep(100000);
	dump_pit();

	return 0;
}
=====

Suggested-by: Sean Christopherson 
Co-developed-by: Li RongQing 
Signed-off-by: Li RongQing 
Signed-off-by: David Woodhouse 
Signed-off-by: Thomas Gleixner 
Tested-by: Michael Kelley 
Link: https://lore.kernel.org/all/20240802135555.564941-2-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman

x86/i8253: Disable PIT timer 0 when not in use

2025-02-21T12:50:12+00:00

commit 70e6b7d9ae3c63df90a7bba7700e8d5c300c3c60 upstream.

Leaving the PIT interrupt running can cause noticeable steal time for
virtual guests. The VMM generally has a timer which toggles the IRQ input
to the PIC and I/O APIC, which takes CPU time away from the guest. Even
on real hardware, running the counter may use power needlessly (albeit
not much).

Make sure it's turned off if it isn't going to be used.

Signed-off-by: David Woodhouse 
Signed-off-by: Thomas Gleixner 
Tested-by: Michael Kelley 
Link: https://lore.kernel.org/all/20240802135555.564941-1-dwmw2@infradead.org
Signed-off-by: Greg Kroah-Hartman

x86/hyperv: Fix hv tsc page based sched_clock for hibernation

2025-01-09T12:29:56+00:00

commit bcc80dec91ee745b3d66f3e48f0ec2efdea97149 upstream.

read_hv_sched_clock_tsc() assumes that the Hyper-V clock counter is
bigger than the variable hv_sched_clock_offset, which is cached during
early boot, but depending on the timing this assumption may be false
when a hibernated VM starts again (the clock counter starts from 0
again) and is resuming back (Note: hv_init_tsc_clocksource() is not
called during hibernation/resume); consequently,
read_hv_sched_clock_tsc() may return a negative integer (which is
interpreted as a huge positive integer since the return type is u64)
and new kernel messages are prefixed with huge timestamps before
read_hv_sched_clock_tsc() grows big enough (which typically takes
several seconds).

Fix the issue by saving the Hyper-V clock counter just before the
suspend, and using it to correct the hv_sched_clock_offset in
resume. This makes hv tsc page based sched_clock continuous and ensures
that post resume, it starts from where it left off during suspend.
Override x86_platform.save_sched_clock_state and
x86_platform.restore_sched_clock_state routines to correct this as soon
as possible.

Note: if Invariant TSC is available, the issue doesn't happen because
1) we don't register read_hv_sched_clock_tsc() for sched clock:
See commit e5313f1c5404 ("clocksource/drivers/hyper-v: Rework
clocksource and sched clock setup");
2) the common x86 code adjusts TSC similarly: see
__restore_processor_state() ->  tsc_verify_tsc_adjust(true) and
x86_platform.restore_sched_clock_state().

Cc: stable@vger.kernel.org
Fixes: 1349401ff1aa ("clocksource/drivers/hyper-v: Suspend/resume Hyper-V clocksource for hibernation")
Co-developed-by: Dexuan Cui 
Signed-off-by: Dexuan Cui 
Signed-off-by: Naman Jain 
Reviewed-by: Michael Kelley 
Link: https://lore.kernel.org/r/20240917053917.76787-1-namjain@linux.microsoft.com
Signed-off-by: Wei Liu 
Message-ID: <20240917053917.76787-1-namjain@linux.microsoft.com>
Signed-off-by: Naman Jain 
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/timer-ti-dm: Fix child node refcount handling

2024-12-14T18:53:19+00:00

[ Upstream commit e5cfc0989d9a2849c51c720a16b90b2c061a1aeb ]

of_find_compatible_node() increments the node's refcount, and it must be
decremented again with a call to of_node_put() when the pointer is no
longer required to avoid leaking the resource.

Instead of adding the missing calls to of_node_put() in all execution
paths, use the cleanup attribute for 'arm_timer' by means of the
__free() macro, which automatically calls of_node_put() when the
variable goes out of scope.

Fixes: 25de4ce5ed02 ("clocksource/drivers/timer-ti-dm: Handle dra7 timer wrap errata i940")
Signed-off-by: Javier Carrasco 
Link: https://lore.kernel.org/r/20241031-timer-ti-dm-systimer-of_node_put-v3-1-063ee822b73a@gmail.com
Signed-off-by: Daniel Lezcano 
Signed-off-by: Sasha Levin

clocksource/drivers:sp804: Make user selectable

2024-12-14T18:53:19+00:00

[ Upstream commit 0309f714a0908e947af1c902cf6a330cb593e75e ]

The sp804 is currently only user selectable if COMPILE_TEST, this was
done by commit dfc82faad725 ("clocksource/drivers/sp804: Add
COMPILE_TEST to CONFIG_ARM_TIMER_SP804") in order to avoid it being
spuriously offered on platforms that won't have the hardware since it's
generally only seen on Arm based platforms.  This config is overly
restrictive, while platforms that rely on the SP804 do select it in
their Kconfig there are others such as the Arm fast models which have a
SP804 available but currently unused by Linux.  Relax the dependency to
allow it to be user selectable on arm and arm64 to avoid surprises and
in case someone comes up with a use for extra timer hardware.

Fixes: dfc82faad725 ("clocksource/drivers/sp804: Add COMPILE_TEST to CONFIG_ARM_TIMER_SP804")
Reported-by: Ross Burton 
Reviewed-by: Sudeep Holla 
Acked-by: Mark Rutland 
Signed-off-by: Mark Brown 
Link: https://lore.kernel.org/r/20241001-arm64-vexpress-sp804-v3-1-0a2d3f7883e4@kernel.org
Signed-off-by: Daniel Lezcano 
Signed-off-by: Sasha Levin

clocksource/drivers/qcom: Add missing iounmap() on errors in msm_dt_timer_init()

2024-10-17T13:20:47+00:00

[ Upstream commit ca140a0dc0a18acd4653b56db211fec9b2339986 ]

Add the missing iounmap() when clock frequency fails to get read by the
of_property_read_u32() call, or if the call to msm_timer_init() fails.

Fixes: 6e3321631ac2 ("ARM: msm: Add DT support to msm_timer")
Signed-off-by: Ankit Agrawal 
Reviewed-by: Konrad Dybcio 
Link: https://lore.kernel.org/r/20240713095713.GA430091@bnew-VirtualBox
Signed-off-by: Daniel Lezcano 
Signed-off-by: Sasha Levin

clocksource/drivers/timer-of: Remove percpu irq related code

2024-09-12T09:10:27+00:00

commit 471ef0b5a8aaca4296108e756b970acfc499ede4 upstream.

GCC's named address space checks errors out with:

drivers/clocksource/timer-of.c: In function ‘timer_of_irq_exit’:
drivers/clocksource/timer-of.c:29:46: error: passing argument 2 of
‘free_percpu_irq’ from pointer to non-enclosed address space
  29 |                 free_percpu_irq(of_irq->irq, clkevt);
     |                                              ^~~~~~
In file included from drivers/clocksource/timer-of.c:8:
./include/linux/interrupt.h:201:43: note: expected ‘__seg_gs void *’
but argument is of type ‘struct clock_event_device *’
 201 | extern void free_percpu_irq(unsigned int, void __percpu *);
     |                                           ^~~~~~~~~~~~~~~
drivers/clocksource/timer-of.c: In function ‘timer_of_irq_init’:
drivers/clocksource/timer-of.c:74:51: error: passing argument 4 of
‘request_percpu_irq’ from pointer to non-enclosed address space
  74 |                                    np->full_name, clkevt) :
     |                                                   ^~~~~~
./include/linux/interrupt.h:190:56: note: expected ‘__seg_gs void *’
but argument is of type ‘struct clock_event_device *’
 190 |                    const char *devname, void __percpu *percpu_dev_id)

Sparse warns about:

timer-of.c:29:46: warning: incorrect type in argument 2 (different address spaces)
timer-of.c:29:46:    expected void [noderef] __percpu *
timer-of.c:29:46:    got struct clock_event_device *clkevt
timer-of.c:74:51: warning: incorrect type in argument 4 (different address spaces)
timer-of.c:74:51:    expected void [noderef] __percpu *percpu_dev_id
timer-of.c:74:51:    got struct clock_event_device *clkevt

It appears the code is incorrect as reported by Uros Bizjak:

"The referred code is questionable as it tries to reuse
the clkevent pointer once as percpu pointer and once as generic
pointer, which should be avoided."

This change removes the percpu related code as no drivers is using it.

[Daniel: Fixed the description]

Fixes: dc11bae785295 ("clocksource/drivers: Add timer-of common init routine")
Reported-by: Uros Bizjak 
Tested-by: Uros Bizjak 
Link: https://lore.kernel.org/r/20240819100335.2394751-1-daniel.lezcano@linaro.org
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/imx-tpm: Fix next event not taking effect sometime

2024-09-12T09:10:27+00:00

commit 3d5c2f8e75a55cfb11a85086c71996af0354a1fb upstream.

The value written into the TPM CnV can only be updated into the hardware
when the counter increases. Additional writes to the CnV write buffer are
ignored until the register has been updated. Therefore, we need to check
if the CnV has been updated before continuing. This may require waiting for
1 counter cycle in the worst case.

Cc: stable@vger.kernel.org
Fixes: 059ab7b82eec ("clocksource/drivers/imx-tpm: Add imx tpm timer support")
Signed-off-by: Jacky Bai 
Reviewed-by: Peng Fan 
Reviewed-by: Ye Li 
Reviewed-by: Jason Liu 
Signed-off-by: Frank Li 
Link: https://lore.kernel.org/r/20240725193355.1436005-2-Frank.Li@nxp.com
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman

clocksource/drivers/imx-tpm: Fix return -ETIME when delta exceeds INT_MAX

2024-09-12T09:10:27+00:00

commit 5b8843fcd49827813da80c0f590a17ae4ce93c5d upstream.

In tpm_set_next_event(delta), return -ETIME by wrong cast to int when delta
is larger than INT_MAX.

For example:

tpm_set_next_event(delta = 0xffff_fffe)
{
        ...
        next = tpm_read_counter(); // assume next is 0x10
        next += delta; // next will 0xffff_fffe + 0x10 = 0x1_0000_000e
        now = tpm_read_counter();  // now is 0x10
        ...

        return (int)(next - now) <= 0 ? -ETIME : 0;
                     ^^^^^^^^^^
                     0x1_0000_000e - 0x10 = 0xffff_fffe, which is -2 when
                     cast to int. So return -ETIME.
}

To fix this, introduce a 'prev' variable and check if 'now - prev' is
larger than delta.

Cc: stable@vger.kernel.org
Fixes: 059ab7b82eec ("clocksource/drivers/imx-tpm: Add imx tpm timer support")
Signed-off-by: Jacky Bai 
Reviewed-by: Peng Fan 
Reviewed-by: Ye Li 
Reviewed-by: Jason Liu 
Signed-off-by: Frank Li 
Link: https://lore.kernel.org/r/20240725193355.1436005-1-Frank.Li@nxp.com
Signed-off-by: Daniel Lezcano 
Signed-off-by: Greg Kroah-Hartman