arm64: Make profile_pc() use arch_stack_walk()

To enable RELIABLE_STACKTRACE and LIVEPATCH on arm64, we need to
substantially rework arm64's unwinding code. As part of this, we want to
minimize the

arm64: Make profile_pc() use arch_stack_walk()

To enable RELIABLE_STACKTRACE and LIVEPATCH on arm64, we need to
substantially rework arm64's unwinding code. As part of this, we want to
minimize the set of unwind interfaces we expose, and avoid open-coding
of unwind logic outside of stacktrace.c.

Currently profile_pc() walks the stack of an interrupted context by
calling start_backtrace() with the context's PC and FP, and iterating
unwind steps using walk_stackframe(). This is functionally equivalent to
calling arch_stack_walk() with the interrupted context's pt_regs, which
will start with the PC and FP from the regs.

Make profile_pc() use arch_stack_walk(). This simplifies profile_pc(),
and in future will alow us to make walk_stackframe() private to
stacktrace.c.

At the same time, we remove the early return for when regs->pc is not in
lock functions, as this will be handled by the first call to the
profile_pc_cb() callback.

There should be no functional change as a result of this patch.

Signed-off-by: Madhavan T. Venkataraman <[email protected]>
Reviewed-by: Mark Rutland <[email protected]>
[Mark: remove early return, elaborate commit message, fix includes]
Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: Mark Brown <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>

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arm64: time: Replace <linux/clk-provider.h> by <linux/of_clk.h>

The arm64 time code is not a clock provider, and just needs to call
of_clk_init().

Hence it can include <linux/of_clk.h> instead of <

arm64: time: Replace <linux/clk-provider.h> by <linux/of_clk.h>

The arm64 time code is not a clock provider, and just needs to call
of_clk_init().

Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.

Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

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arm64: Retrieve stolen time as paravirtualized guest

Enable paravirtualization features when running under a hypervisor
supporting the PV_TIME_ST hypercall.

For each (v)CPU, we ask the hypervisor f

arm64: Retrieve stolen time as paravirtualized guest

Enable paravirtualization features when running under a hypervisor
supporting the PV_TIME_ST hypercall.

For each (v)CPU, we ask the hypervisor for the location of a shared
page which the hypervisor will use to report stolen time to us. We set
pv_time_ops to the stolen time function which simply reads the stolen
value from the shared page for a VCPU. We guarantee single-copy
atomicity using READ_ONCE which means we can also read the stolen
time for another VCPU than the currently running one while it is
potentially being updated by the hypervisor.

Signed-off-by: Steven Price <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>

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arm64: stacktrace: Factor out backtrace initialisation

Some common code is required by each stacktrace user to initialise
struct stackframe before the first call to unwind_frame().

In preparation f

arm64: stacktrace: Factor out backtrace initialisation

Some common code is required by each stacktrace user to initialise
struct stackframe before the first call to unwind_frame().

In preparation for adding to the common code, this patch factors it
out into a separate function start_backtrace(), and modifies the
stacktrace callers appropriately.

No functional change.

Signed-off-by: Dave Martin <[email protected]>
[Mark: drop tsk argument, update more callsites]
Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: James Morse <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of th

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

Based on 1 normalized pattern(s):

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 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 you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Alexios Zavras <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Reviewed-by: Enrico Weigelt <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack

The structure of the ret_stack array on the task struct is going to
change, and accessing it directly via the curr_ret_stack index w

arm64: Use ftrace_graph_get_ret_stack() instead of curr_ret_stack

The structure of the ret_stack array on the task struct is going to
change, and accessing it directly via the curr_ret_stack index will no
longer give the ret_stack entry that holds the return address. To access
that, architectures must now use ftrace_graph_get_ret_stack() to get the
associated ret_stack that matches the saved return address.

Cc: [email protected]
Cc: Will Deacon <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

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arm64: fix unwind_frame() for filtered out fn for function graph tracing

do_task_stat() calls get_wchan(), which further does unwind_frame().
unwind_frame() restores frame->pc to original value in c

arm64: fix unwind_frame() for filtered out fn for function graph tracing

do_task_stat() calls get_wchan(), which further does unwind_frame().
unwind_frame() restores frame->pc to original value in case function
graph tracer has modified a return address (LR) in a stack frame to hook
a function return. However, if function graph tracer has hit a filtered
function, then we can't unwind it as ftrace_push_return_trace() has
biased the index(frame->graph) with a 'huge negative'
offset(-FTRACE_NOTRACE_DEPTH).

Moreover, arm64 stack walker defines index(frame->graph) as unsigned
int, which can not compare a -ve number.

Similar problem we can have with calling of walk_stackframe() from
save_stack_trace_tsk() or dump_backtrace().

This patch fixes unwind_frame() to test the index for -ve value and
restore index accordingly before we can restore frame->pc.

Reproducer:

cd /sys/kernel/debug/tracing/
echo schedule > set_graph_notrace
echo 1 > options/display-graph
echo wakeup > current_tracer
ps -ef | grep -i agent

Above commands result in:
Unable to handle kernel paging request at virtual address ffff801bd3d1e000
pgd = ffff8003cbe97c00
[ffff801bd3d1e000] *pgd=0000000000000000, *pud=0000000000000000
Internal error: Oops: 96000006 [#1] SMP
[...]
CPU: 5 PID: 11696 Comm: ps Not tainted 4.11.0+ #33
[...]
task: ffff8003c21ba000 task.stack: ffff8003cc6c0000
PC is at unwind_frame+0x12c/0x180
LR is at get_wchan+0xd4/0x134
pc : [<ffff00000808892c>] lr : [<ffff0000080860b8>] pstate: 60000145
sp : ffff8003cc6c3ab0
x29: ffff8003cc6c3ab0 x28: 0000000000000001
x27: 0000000000000026 x26: 0000000000000026
x25: 00000000000012d8 x24: 0000000000000000
x23: ffff8003c1c04000 x22: ffff000008c83000
x21: ffff8003c1c00000 x20: 000000000000000f
x19: ffff8003c1bc0000 x18: 0000fffffc593690
x17: 0000000000000000 x16: 0000000000000001
x15: 0000b855670e2b60 x14: 0003e97f22cf1d0f
x13: 0000000000000001 x12: 0000000000000000
x11: 00000000e8f4883e x10: 0000000154f47ec8
x9 : 0000000070f367c0 x8 : 0000000000000000
x7 : 00008003f7290000 x6 : 0000000000000018
x5 : 0000000000000000 x4 : ffff8003c1c03cb0
x3 : ffff8003c1c03ca0 x2 : 00000017ffe80000
x1 : ffff8003cc6c3af8 x0 : ffff8003d3e9e000

Process ps (pid: 11696, stack limit = 0xffff8003cc6c0000)
Stack: (0xffff8003cc6c3ab0 to 0xffff8003cc6c4000)
[...]
[<ffff00000808892c>] unwind_frame+0x12c/0x180
[<ffff000008305008>] do_task_stat+0x864/0x870
[<ffff000008305c44>] proc_tgid_stat+0x3c/0x48
[<ffff0000082fde0c>] proc_single_show+0x5c/0xb8
[<ffff0000082b27e0>] seq_read+0x160/0x414
[<ffff000008289e6c>] __vfs_read+0x58/0x164
[<ffff00000828b164>] vfs_read+0x88/0x144
[<ffff00000828c2e8>] SyS_read+0x60/0xc0
[<ffff0000080834a0>] __sys_trace_return+0x0/0x4

Fixes: 20380bb390a4 (arm64: ftrace: fix a stack tracer's output under function graph tracer)
Signed-off-by: Pratyush Anand <[email protected]>
Signed-off-by: Jerome Marchand <[email protected]>
[[email protected]: replace WARN_ON with WARN_ON_ONCE]
Signed-off-by: Catalin Marinas <[email protected]>

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arm64: unwind: remove sp from struct stackframe

The unwind code sets the sp member of struct stackframe to
'frame pointer + 0x10' unconditionally, without regard for whether
doing so produces a lega

arm64: unwind: remove sp from struct stackframe

The unwind code sets the sp member of struct stackframe to
'frame pointer + 0x10' unconditionally, without regard for whether
doing so produces a legal value. So let's simply remove it now that
we have stopped using it anyway.

Signed-off-by: Ard Biesheuvel <[email protected]>
Signed-off-by: Mark Rutland <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: James Morse <[email protected]>
Cc: Will Deacon <[email protected]>

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clocksource/drivers: Rename clocksource_probe to timer_probe

The function name is now renamed to 'timer_probe' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off

clocksource/drivers: Rename clocksource_probe to timer_probe

The function name is now renamed to 'timer_probe' for consistency with
the CLOCKSOURCE_OF_DECLARE => TIMER_OF_DECLARE change.

Signed-off-by: Daniel Lezcano <[email protected]>
Acked-by: Viresh Kumar <[email protected]>
Acked-by: Heiko Stuebner <[email protected]>
Reviewed-by: Linus Walleij <[email protected]>

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arm64: ftrace: fix a stack tracer's output under function graph tracer

Function graph tracer modifies a return address (LR) in a stack frame
to hook a function return. This will result in many usele

arm64: ftrace: fix a stack tracer's output under function graph tracer

Function graph tracer modifies a return address (LR) in a stack frame
to hook a function return. This will result in many useless entries
(return_to_handler) showing up in
a) a stack tracer's output
b) perf call graph (with perf record -g)
c) dump_backtrace (at panic et al.)

For example, in case of a),
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ echo 1 > /proc/sys/kernel/stack_trace_enabled
$ cat /sys/kernel/debug/tracing/stack_trace
Depth Size Location (54 entries)
----- ---- --------
0) 4504 16 gic_raise_softirq+0x28/0x150
1) 4488 80 smp_cross_call+0x38/0xb8
2) 4408 48 return_to_handler+0x0/0x40
3) 4360 32 return_to_handler+0x0/0x40
...

In case of b),
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ perf record -e mem:XXX:x -ag -- sleep 10
$ perf report
...
| | |--0.22%-- 0x550f8
| | | 0x10888
| | | el0_svc_naked
| | | sys_openat
| | | return_to_handler
| | | return_to_handler
...

In case of c),
$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
$ echo c > /proc/sysrq-trigger
...
Call trace:
[<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30
[<ffffffc000092250>] return_to_handler+0x0/0x40
[<ffffffc000092250>] return_to_handler+0x0/0x40
...

This patch replaces such entries with real addresses preserved in
current->ret_stack[] at unwind_frame(). This way, we can cover all
the cases.

Reviewed-by: Jungseok Lee <[email protected]>
Signed-off-by: AKASHI Takahiro <[email protected]>
[will: fixed minor context changes conflicting with irq stack bits]
Signed-off-by: Will Deacon <[email protected]>

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arm64: pass a task parameter to unwind_frame()

Function graph tracer modifies a return address (LR) in a stack frame
to hook a function's return. This will result in many useless entries
(return_to_

arm64: pass a task parameter to unwind_frame()

Function graph tracer modifies a return address (LR) in a stack frame
to hook a function's return. This will result in many useless entries
(return_to_handler) showing up in a call stack list.
We will fix this problem in a later patch ("arm64: ftrace: fix a stack
tracer's output under function graph tracer"). But since real return
addresses are saved in ret_stack[] array in struct task_struct,
unwind functions need to be notified of, in addition to a stack pointer
address, which task is being traced in order to find out real return
addresses.

This patch extends unwind functions' interfaces by adding an extra
argument of a pointer to task_struct.

Signed-off-by: AKASHI Takahiro <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

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clocksource: cosmetic: Drop OF 'dependency' from symbols

Seeing the 'of' characters in a symbol that is being called from
ACPI seems to freak out people. So let's do a bit of pointless
renaming so t

clocksource: cosmetic: Drop OF 'dependency' from symbols

Seeing the 'of' characters in a symbol that is being called from
ACPI seems to freak out people. So let's do a bit of pointless
renaming so that these folks do feel at home.

Signed-off-by: Marc Zyngier <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Reviewed-by: Hanjun Guo <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Tested-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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clocksource / arm_arch_timer: Convert to ACPI probing

It is now absolutely trivial to convert the arch timer driver to
use ACPI probing, just like its DT counterpart.

Let's enjoy another crapectomy

clocksource / arm_arch_timer: Convert to ACPI probing

It is now absolutely trivial to convert the arch timer driver to
use ACPI probing, just like its DT counterpart.

Let's enjoy another crapectomy.

Signed-off-by: Marc Zyngier <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Tested-by: Hanjun Guo <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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arm64: force CONFIG_SMP=y and remove redundant #ifdefs

Nobody seems to be producing !SMP systems anymore, so this is just
becoming a source of kernel bugs, particularly if people want to use
coheren

arm64: force CONFIG_SMP=y and remove redundant #ifdefs

Nobody seems to be producing !SMP systems anymore, so this is just
becoming a source of kernel bugs, particularly if people want to use
coherent DMA with non-shared pages.

This patch forces CONFIG_SMP=y for arm64, removing a modest amount of
code in the process.

Signed-off-by: Will Deacon <[email protected]>

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clocksource / arch_timer: Parse GTDT to initialize arch timer

Using the information presented by GTDT (Generic Timer Description Table)
to initialize the arch timer (not memory-mapped).

CC: Daniel

clocksource / arch_timer: Parse GTDT to initialize arch timer

Using the information presented by GTDT (Generic Timer Description Table)
to initialize the arch timer (not memory-mapped).

CC: Daniel Lezcano <[email protected]>
CC: Thomas Gleixner <[email protected]>
Originally-by: Amit Daniel Kachhap <[email protected]>
Tested-by: Suravee Suthikulpanit <[email protected]>
Tested-by: Yijing Wang <[email protected]>
Tested-by: Mark Langsdorf <[email protected]>
Tested-by: Jon Masters <[email protected]>
Tested-by: Timur Tabi <[email protected]>
Tested-by: Robert Richter <[email protected]>
Acked-by: Robert Richter <[email protected]>
Acked-by: Daniel Lezcano <[email protected]>
Reviewed-by: Grant Likely <[email protected]>
Signed-off-by: Hanjun Guo <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

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arm64: kernel: initialize broadcast hrtimer based clock event device

On platforms implementing CPU power management, the CPUidle subsystem
can allow CPUs to enter idle states where local timers logi

arm64: kernel: initialize broadcast hrtimer based clock event device

On platforms implementing CPU power management, the CPUidle subsystem
can allow CPUs to enter idle states where local timers logic is lost on power
down. To keep the software timers functional the kernel relies on an
always-on broadcast timer to be present in the platform to relay the
interrupt signalling the timer expiries.

For platforms implementing CPU core gating that do not implement an always-on
HW timer or implement it in a broken way, this patch adds code to initialize
the kernel hrtimer based clock event device upon boot (which can be chosen as
tick broadcast device by the kernel).
It relies on a dynamically chosen CPU to be always powered-up. This CPU then
relays the timer interrupt to CPUs in deep-idle states through its HW local
timer device.

Having a CPU always-on has implications on power management platform
capabilities and makes CPUidle suboptimal, since at least a CPU is kept
always in a shallow idle state by the kernel to relay timer interrupts,
but at least leaves the kernel with a functional system with some working
power management capabilities.

The hrtimer based clock event device is unconditionally registered, but
has the lowest possible rating such that any broadcast-capable HW clock
event device present will be chosen in preference as the tick broadcast
device.

Reviewed-by: Preeti U Murthy <[email protected]>
Acked-by: Will Deacon <[email protected]>
Acked-by: Mark Rutland <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

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arm64: init: Move of_clk_init to time_init

Clock providers should be initialized before clocksource_of_init.
If not, Clock source initialization can be fail to get the clock.

Acked-by: Will Deacon

arm64: init: Move of_clk_init to time_init

Clock providers should be initialized before clocksource_of_init.
If not, Clock source initialization can be fail to get the clock.

Acked-by: Will Deacon <[email protected]>
Signed-off-by: Chanho Min <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>

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arch_timer: Move to generic sched_clock framework

Register with the generic sched_clock framework now that it
supports 64 bits. This fixes two problems with the current
sched_clock support for machi

arch_timer: Move to generic sched_clock framework

Register with the generic sched_clock framework now that it
supports 64 bits. This fixes two problems with the current
sched_clock support for machines using the architected timers.
First off, we don't subtract the start value from subsequent
sched_clock calls so we can potentially start off with
sched_clock returning gigantic numbers. Second, there is no
support for suspend/resume handling so problems such as discussed
in 6a4dae5 (ARM: 7565/1: sched: stop sched_clock() during
suspend, 2012-10-23) can happen without this patch. Finally, it
allows us to move the sched_clock setup into drivers clocksource
out of the arch ports.

Cc: Christopher Covington <[email protected]>
Cc: Catalin Marinas <[email protected]>
Acked-by: Will Deacon <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: John Stultz <[email protected]>

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arm64: kernel: compiling issue, need delete read_current_timer()

Under arm64, we will calibrate the delay loop statically using a known
timer frequency, so delete read_current_timer(), or it will ca

arm64: kernel: compiling issue, need delete read_current_timer()

Under arm64, we will calibrate the delay loop statically using a known
timer frequency, so delete read_current_timer(), or it will cause
compiling issue with allmodconfig.

The related error:
ERROR: "read_current_timer" [lib/rbtree_test.ko] undefined!
ERROR: "read_current_timer" [lib/interval_tree_test.ko] undefined!
ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!
ERROR: "read_current_timer" [crypto/tcrypt.ko] undefined!

Signed-off-by: Chen Gang <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>

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ARM: convert arm/arm64 arch timer to use CLKSRC_OF init

This converts arm and arm64 to use CLKSRC_OF DT based initialization for
the arch timer. A new function arch_timer_arch_init is added to allow

ARM: convert arm/arm64 arch timer to use CLKSRC_OF init

This converts arm and arm64 to use CLKSRC_OF DT based initialization for
the arch timer. A new function arch_timer_arch_init is added to allow for
arch specific setup.

This has a side effect of enabling sched_clock on omap5 and exynos5. There
should not be any reason not to use the arch timers for sched_clock.

Signed-off-by: Rob Herring <[email protected]>
Cc: Russell King <[email protected]>
Cc: Kukjin Kim <[email protected]>
Cc: Tony Lindgren <[email protected]>
Cc: Simon Horman <[email protected]>
Cc: Magnus Damm <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Acked-by: Santosh Shilimkar <[email protected]>

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arm64: move from arm_generic to arm_arch_timer

The arch_timer driver supports a superset of the functionality of the
arm_generic driver, and is not tied to a particular arch.

This patch moves arm64

arm64: move from arm_generic to arm_arch_timer

The arch_timer driver supports a superset of the functionality of the
arm_generic driver, and is not tied to a particular arch.

This patch moves arm64 to use the arch_timer driver, gaining additional
functionality in doing so, and removes the (now unused) arm_generic
driver. Timer-related hooks specific to arm64 are moved into
arch/arm64/kernel/time.c.

Signed-off-by: Mark Rutland <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Acked-by: Santosh Shilimkar <[email protected]>

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arm64: Generic timers support

This patch adds support for the ARM generic timers with A64 instructions
for accessing the timer registers. It uses the physical counter as the
clock source and the vir

arm64: Generic timers support

This patch adds support for the ARM generic timers with A64 instructions
for accessing the timer registers. It uses the physical counter as the
clock source and the virtual counter as sched_clock.

The timer frequency can be specified via DT or read from the CNTFRQ_EL0
register. The physical counter is also accessible from user space
allowing fast gettimeofday() implementation.

Signed-off-by: Marc Zyngier <[email protected]>
Signed-off-by: Will Deacon <[email protected]>
Signed-off-by: Catalin Marinas <[email protected]>
Acked-by: Tony Lindgren <[email protected]>
Acked-by: Nicolas Pitre <[email protected]>
Acked-by: Olof Johansson <[email protected]>
Acked-by: Santosh Shilimkar <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>

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