[patch 00/38] treewide: Cleanup LATCH, CLOCK_TICK_RATE and get_cycles() [ab]use

[patch 00/38] treewide: Cleanup LATCH, CLOCK_TICK_RATE and get_cycles() [ab]use

[Thomas Gleixner]

First of all sorry for the insanely big Cc list, but people can't make
their mind up whether they want to be Cc'ed on everything or not. So I'm
opting for the worst case to cater to the people who want to be Cc'ed on
everything and assume that the rest of you got used to it by now. I really
wanted this to be more confined but a treewide cleanup does not give a lot
of options.

That said, let me explain what this is about.

  1) LATCH

     The LATCH define goes back to Linux version 0.1 and has survived until
     today for the very wrong reasons.

     Initially it was based on the x86 PIT frequency and also steered the
     timekeeping conversions.

     With the arrival of non x86 architectures it got changed to be based
     on CLOCK_TICK_RATE in order not to change core code which depended on
     LATCH.

     That all got meaningless when timers, timekeeping and scheduling
     infrastructure got rewritten more than two decades ago.

     But there is still a lonely survivor in arch/x86/kernel/apm_32.c
     which dates back to Linux 1.3.46 (Dec. 1995)

     Which causes the next historical gem

  2) CLOCK_TICK_RATE

     When Linux got expanded beyond i386 LATCH was made "flexible" by
     basing it on CLOCK_TICK_RATE to adjust for other frequencies than the
     i386 PIT frequency.

     As LATCH this got meaningless long ago and for amusement value it got
     copied into new architectures arriving way after it got obsolete for
     no reason but with comments to the effect that it's meaningless

     And of course it had a lonely survivor in arch/x86/kernel/setup.c
     despite it being only an alias for PIT_TICK_RATE for a very long time.

  3) get_cycles()

     That was introduced in 2.1.133pre4 (Dec. 1998) to utilize the back
     then brand new TSC. The introduction broke everything except i386 SMP
     with a CPU having a TSC and got then fixed up within a couple of days
     with empty stubs returning 0 and #ifdeffery for CONFIG_TSC before the
     2.2.0 release.

     It's amusing that the naming deliberately ignored that TSC is the
     acronym for Time Stamp Counter and not Cycle Counter and rather went
     for the underlying coincidence that the TSC was running at the same
     fixed frequency as the CPU core.

     That turned out to be interesting when CPUs started to have frequency
     scaling as the TSC then turned into a variable frequency random number
     generator.

     A decade later CPU designers came to senses and made the TSC invariant
     usually running at the nominal CPU frequency, which allowed to use it
     for reliable timekeeping purposes.

     Non x86 architectures implemented get_cycles() based on whatever
     continuously running counter they had available in their CPUs. Some of
     them actual CPU cycle counters, but many of them running at a fixed
     frequency which was completely unrelated to CPU cycles.

     Around 2004/5 the timekeeping subsystem was completely rewritten and
     made generic along with the scheduling clock and other related
     infrastructure. With that rewrite get_cycles() got mostly obsolete,
     but despite it being on the todo list of quite some people it never
     ceased to exist and it was just a conveniance vehicle to base other
     things like the recent addition of random_get_entropy() on top with a
     hideous #ifdef/#define macro maze.

     The other remaining use cases are mostly debugging and testing
     code. Especially the usage in performance test code is hillarious at
     best. While the name get_cycles() suggests that it provides access to
     CPU cycles the reality is that it provides a unspecified counter for
     most systems, where a lot of architectures simply return 0 because
     they either do not have such a counter or did not bother to implement
     it at all.

     So in fact get_cycles() should have been renamed to get_bogo_cycles()
     long ago matching the BogoMIPS "impress your friends" printk which
     still exists for historical amusement value.

     But the real solution is to remove it all together instead of
     proliferating the bogosity.


This is what this series does with the following steps:

   1) Cleanup some header dependency hell which got unearthed by the
      restructuring and went unnoticed so far. It's amazing how the kernel
      build system magically "works". This affects not only x86, but the
      main fallout was observed and fixed there. ARM64 and MIPS are at
      least as bad as they silently rely on the accidental asm/timex.h
      include through a variety of generic headers to make their
      architecture code compile. See the changelog and patches specific to
      those two.

   2) Removal of LATCH

   3) Removal of CLOCK_TICK_RATE

   4) Consolidation of cycles_t which was a typedef in asm/timex.h

   5) Cleanup of read_current_timer() which is only used for delay
      calibration and has nothing to do with get_cycles()

   6) Cleanup of get_cycles() usage in debug and test code

   7) Decoupling of random_get_entropy() from get_cycles()

   8) Removal of asm/timex.h includes except for architecture internal
      usage where necessary.

At the end get_cycles() survives in a couple of architectures as a purely
architecture internal implementation detail.

This survives compile testing on all architectures except hexagon and nios2
because the current cross tools based on gcc15 do not offer a compiler for
them anymore. Boot tested on x86 and some qemu instances covering only a
few architectures.

The series applies on v7.0-rc7 and with very minor conflicts on -next. It
is also available from git:

    git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git getcycles-v1

Thanks,

	tglx
---
 arch/alpha/include/asm/timex.h                 |   33 --------
 arch/arc/include/asm/timex.h                   |   15 ---
 arch/arm/include/asm/timex.h                   |   16 ---
 arch/arm64/include/asm/timex.h                 |   18 ----
 arch/hexagon/include/asm/timex.h               |   23 -----
 arch/m68k/include/asm/timex.h                  |   42 ----------
 arch/microblaze/include/asm/timex.h            |   13 ---
 arch/mips/include/asm/timex.h                  |  102 -------------------------
 arch/sh/include/asm/timex.h                    |   24 -----
 arch/sparc/include/asm/timex.h                 |    9 --
 arch/sparc/include/asm/timex_32.h              |   14 ---
 arch/um/include/asm/timex.h                    |    9 --
 b/Documentation/fb/udlfb.rst                   |    4 
 b/arch/Kconfig                                 |   10 ++
 b/arch/alpha/Kconfig                           |    1 
 b/arch/alpha/include/asm/random.h              |   14 +++
 b/arch/arm/Kconfig                             |    2 
 b/arch/arm/include/asm/delay.h                 |    1 
 b/arch/arm/include/asm/random.h                |   14 +++
 b/arch/arm/lib/delay.c                         |   14 +--
 b/arch/arm/mach-omap1/Kconfig                  |    2 
 b/arch/arm64/Kconfig                           |    2 
 b/arch/arm64/include/asm/io.h                  |    5 -
 b/arch/arm64/include/asm/ptp_vmclock.h         |   12 ++
 b/arch/arm64/include/asm/random.h              |   11 ++
 b/arch/arm64/include/asm/rqspinlock.h          |    1 
 b/arch/arm64/kernel/time.c                     |    6 +
 b/arch/arm64/kernel/topology.c                 |    1 
 b/arch/arm64/kernel/traps.c                    |    1 
 b/arch/arm64/kvm/emulate-nested.c              |    1 
 b/arch/arm64/kvm/hyp/include/hyp/switch.h      |    1 
 b/arch/arm64/lib/delay.c                       |    1 
 b/arch/hexagon/Kconfig                         |    1 
 b/arch/hexagon/kernel/time.c                   |    8 +
 b/arch/loongarch/Kconfig                       |    1 
 b/arch/loongarch/include/asm/random.h          |   15 +++
 b/arch/loongarch/include/asm/timex.h           |    2 
 b/arch/loongarch/kernel/relocate.c             |    1 
 b/arch/loongarch/kernel/syscall.c              |    1 
 b/arch/loongarch/lib/delay.c                   |    2 
 b/arch/m68k/Kconfig                            |    1 
 b/arch/m68k/amiga/config.c                     |    1 
 b/arch/m68k/include/asm/random.h               |   14 +++
 b/arch/m68k/kernel/time.c                      |    2 
 b/arch/mips/Kconfig                            |    1 
 b/arch/mips/generic/init.c                     |    1 
 b/arch/mips/include/asm/random.h               |    7 +
 b/arch/mips/kernel/pm-cps.c                    |    1 
 b/arch/mips/kernel/proc.c                      |    1 
 b/arch/mips/kernel/relocate.c                  |    2 
 b/arch/mips/kernel/time.c                      |   53 ++++++++++++
 b/arch/mips/lib/dump_tlb.c                     |    1 
 b/arch/mips/mm/cache.c                         |    1 
 b/arch/nios2/Kconfig                           |    1 
 b/arch/nios2/include/asm/random.h              |   14 +++
 b/arch/nios2/include/asm/timex.h               |    7 -
 b/arch/nios2/kernel/time.c                     |    4 
 b/arch/openrisc/Kconfig                        |    2 
 b/arch/openrisc/include/asm/random.h           |   12 ++
 b/arch/openrisc/include/asm/timex.h            |   10 --
 b/arch/openrisc/lib/delay.c                    |    8 -
 b/arch/parisc/Kconfig                          |    1 
 b/arch/parisc/include/asm/random.h             |   12 ++
 b/arch/parisc/include/asm/timex.h              |   10 --
 b/arch/parisc/kernel/processor.c               |    1 
 b/arch/parisc/kernel/time.c                    |    1 
 b/arch/powerpc/Kconfig                         |    1 
 b/arch/powerpc/include/asm/random.h            |   13 +++
 b/arch/powerpc/include/asm/timex.h             |   25 ------
 b/arch/powerpc/platforms/cell/spufs/switch.c   |    5 -
 b/arch/riscv/Kconfig                           |    2 
 b/arch/riscv/include/asm/random.h              |   25 ++++++
 b/arch/riscv/include/asm/timex.h               |   23 -----
 b/arch/riscv/kernel/unaligned_access_speed.c   |    1 
 b/arch/riscv/kvm/vcpu_timer.c                  |    1 
 b/arch/riscv/lib/delay.c                       |    8 +
 b/arch/s390/Kconfig                            |    1 
 b/arch/s390/include/asm/random.h               |   12 ++
 b/arch/s390/include/asm/timex.h                |   10 --
 b/arch/s390/kernel/time.c                      |    1 
 b/arch/s390/kernel/vtime.c                     |    1 
 b/arch/sparc/Kconfig                           |    2 
 b/arch/sparc/include/asm/random.h              |   15 +++
 b/arch/sparc/include/asm/timex_64.h            |   20 ----
 b/arch/sparc/kernel/pcic.c                     |    1 
 b/arch/sparc/kernel/time_32.c                  |    1 
 b/arch/sparc/kernel/time_64.c                  |    4 
 b/arch/sparc/vdso/vclock_gettime.c             |    1 
 b/arch/x86/Kconfig                             |    4 
 b/arch/x86/include/asm/iommu.h                 |    3 
 b/arch/x86/include/asm/msr.h                   |    5 -
 b/arch/x86/include/asm/percpu.h                |    5 -
 b/arch/x86/include/asm/percpu_types.h          |   17 ++++
 b/arch/x86/include/asm/ptp_vmclock.h           |   12 ++
 b/arch/x86/include/asm/pvclock.h               |    1 
 b/arch/x86/include/asm/random.h                |   12 --
 b/arch/x86/include/asm/smp.h                   |    2 
 b/arch/x86/include/asm/tsc.h                   |   11 --
 b/arch/x86/include/asm/vdso/gettimeofday.h     |    5 -
 b/arch/x86/kernel/apm_32.c                     |    4 
 b/arch/x86/kernel/cpu/mce/core.c               |    1 
 b/arch/x86/kernel/nmi.c                        |    1 
 b/arch/x86/kernel/setup.c                      |    2 
 b/arch/x86/kernel/smpboot.c                    |    1 
 b/arch/x86/kernel/tsc.c                        |   12 +-
 b/arch/x86/lib/delay.c                         |    8 -
 b/crypto/jitterentropy-kcapi.c                 |    1 
 b/crypto/tcrypt.c                              |   84 ++++++++++----------
 b/drivers/iommu/intel/dmar.c                   |    4 
 b/drivers/iommu/intel/iommu.h                  |    8 +
 b/drivers/irqchip/irq-apple-aic.c              |    1 
 b/drivers/misc/sgi-gru/gruhandles.c            |   20 +---
 b/drivers/misc/sgi-gru/grukservices.c          |    3 
 b/drivers/misc/sgi-gru/grutlbpurge.c           |    5 -
 b/drivers/net/arcnet/arc-rimi.c                |    4 
 b/drivers/net/arcnet/arcdevice.h               |   20 ----
 b/drivers/net/arcnet/com20020.c                |    6 -
 b/drivers/net/arcnet/com90io.c                 |    6 -
 b/drivers/net/arcnet/com90xx.c                 |    4 
 b/drivers/net/hamradio/baycom_epp.c            |   51 ------------
 b/drivers/net/wireless/ath/wil6210/debugfs.c   |    2 
 b/drivers/net/wireless/ath/wil6210/txrx.c      |    6 -
 b/drivers/net/wireless/ath/wil6210/txrx_edma.c |    4 
 b/drivers/net/wireless/ath/wil6210/wil6210.h   |    3 
 b/drivers/ptp/Kconfig                          |    6 -
 b/drivers/ptp/ptp_vmclock.c                    |    6 -
 b/drivers/video/fbdev/udlfb.c                  |   24 ++---
 b/fs/ext4/mballoc.c                            |    4 
 b/include/asm-generic/Kbuild                   |    2 
 b/include/asm-generic/percpu_types.h           |   20 ++++
 b/include/linux/compiler_types.h               |    1 
 b/include/linux/delay.h                        |    2 
 b/include/linux/jiffies.h                      |    3 
 b/include/linux/random.h                       |   18 ++++
 b/include/linux/timex.h                        |   26 ------
 b/include/linux/types.h                        |    6 +
 b/init/calibrate.c                             |   19 ++--
 b/kernel/kcsan/core.c                          |    3 
 b/kernel/kcsan/debugfs.c                       |    8 -
 b/kernel/time/timer.c                          |    1 
 b/lib/interval_tree_test.c                     |   17 +---
 b/lib/rbtree_test.c                            |   47 +++++------
 b/lib/test_vmalloc.c                           |   10 +-
 b/mm/kasan/sw_tags.c                           |    2 
 b/mm/slub.c                                    |   37 +++++----
 include/asm-generic/timex.h                    |   23 -----
 146 files changed, 622 insertions(+), 796 deletions(-)

[patch 01/38] percpu: Sanitize __percpu_qual include hell

[Thomas Gleixner]

Slapping __percpu_qual into the next available header is sloppy at best.

It's required by __percpu which is defined in compiler_types.h and that is
meant to be included without requiring a boatload of other headers so that
a struct or function declaration can contain a __percpu qualifier w/o
further prerequisites.

This implicit dependency on linux/percpu.h makes that impossible and causes
a major problem when trying to seperate headers.

Create asm/percpu_types.h and move it there. Include that from
compiler_types.h and the whole recursion problem goes away.

Signed-off-by: Thomas Gleixner <tglx@kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/x86/include/asm/percpu.h       |    5 -----
 arch/x86/include/asm/percpu_types.h |   17 +++++++++++++++++
 include/asm-generic/Kbuild          |    1 +
 include/asm-generic/percpu_types.h  |   20 ++++++++++++++++++++
 include/linux/compiler_types.h      |    1 +
 5 files changed, 39 insertions(+), 5 deletions(-)

--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -40,12 +40,10 @@
 #endif
 
 #define __percpu_prefix
-#define __percpu_seg_override	CONCATENATE(__seg_, __percpu_seg)
 
 #else /* !CONFIG_CC_HAS_NAMED_AS: */
 
 #define __percpu_prefix		__force_percpu_prefix
-#define __percpu_seg_override
 
 #endif /* CONFIG_CC_HAS_NAMED_AS */
 
@@ -82,7 +80,6 @@
 
 #define __force_percpu_prefix
 #define __percpu_prefix
-#define __percpu_seg_override
 
 #define PER_CPU_VAR(var)	(var)__percpu_rel
 
@@ -92,8 +89,6 @@
 # define __my_cpu_type(var)	typeof(var)
 # define __my_cpu_ptr(ptr)	(ptr)
 # define __my_cpu_var(var)	(var)
-
-# define __percpu_qual		__percpu_seg_override
 #else
 # define __my_cpu_type(var)	typeof(var) __percpu_seg_override
 # define __my_cpu_ptr(ptr)	(__my_cpu_type(*(ptr))*)(__force uintptr_t)(ptr)
--- /dev/null
+++ b/arch/x86/include/asm/percpu_types.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_PERCPU_TYPES_H
+#define _ASM_X86_PERCPU_TYPES_H
+
+#if defined(CONFIG_SMP) && defined(CONFIG_CC_HAS_NAMED_AS)
+#define __percpu_seg_override	CONCATENATE(__seg_, __percpu_seg)
+#else /* !CONFIG_CC_HAS_NAMED_AS: */
+#define __percpu_seg_override
+#endif
+
+#if defined(CONFIG_USE_X86_SEG_SUPPORT) && defined(USE_TYPEOF_UNQUAL)
+#define __percpu_qual		__percpu_seg_override
+#endif
+
+#include <asm-generic/percpu_types.h>
+
+#endif
--- a/include/asm-generic/Kbuild
+++ b/include/asm-generic/Kbuild
@@ -44,6 +44,7 @@ mandatory-y += module.lds.h
 mandatory-y += msi.h
 mandatory-y += pci.h
 mandatory-y += percpu.h
+mandatory-y += percpu_types.h
 mandatory-y += pgalloc.h
 mandatory-y += preempt.h
 mandatory-y += rqspinlock.h
--- /dev/null
+++ b/include/asm-generic/percpu_types.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_PERCPU_TYPES_H_
+#define _ASM_GENERIC_PERCPU_TYPES_H_
+
+#ifndef __ASSEMBLER__
+/*
+ * __percpu_qual is the qualifier for the percpu named address space.
+ *
+ * Most arches use generic named address space for percpu variables but
+ * some arches define percpu variables in different named address space
+ * (on the x86 arch, percpu variable may be declared as being relative
+ * to the %fs or %gs segments using __seg_fs or __seg_gs named address
+ * space qualifier).
+ */
+#ifndef __percpu_qual
+# define __percpu_qual
+#endif
+
+#endif /* __ASSEMBLER__ */
+#endif /* _ASM_GENERIC_PERCPU_TYPES_H_ */
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -41,6 +41,7 @@
 # define BTF_TYPE_TAG(value) /* nothing */
 #endif
 
+#include <asm/percpu_types.h>
 #include <linux/compiler-context-analysis.h>
 
 /* sparse defines __CHECKER__; see Documentation/dev-tools/sparse.rst */

[patch 02/38] x86: Cleanup include recursion hell

[Thomas Gleixner]

Including a random architecture specific header which requires global
headers just to avoid including that header at the two usage sites is
really beyond lazy and tasteless. Including global headers just to get the
__percpu macro from linux/compiler_types.h falls into the same category.

Remove the linux/percpu.h and asm/cpumask.h includes from msr.h and smp.h
and fix the resulting fallout by a simple forward struct declaration and by
including the x86 specific asm/cpumask.h header where it is actually
required.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/x86/include/asm/msr.h               |    5 +++--
 arch/x86/include/asm/pvclock.h           |    1 +
 arch/x86/include/asm/smp.h               |    2 --
 arch/x86/include/asm/vdso/gettimeofday.h |    5 ++---
 arch/x86/kernel/cpu/mce/core.c           |    1 +
 arch/x86/kernel/nmi.c                    |    1 +
 arch/x86/kernel/smpboot.c                |    1 +
 7 files changed, 9 insertions(+), 7 deletions(-)

--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -8,12 +8,11 @@
 
 #include <asm/asm.h>
 #include <asm/errno.h>
-#include <asm/cpumask.h>
 #include <uapi/asm/msr.h>
 #include <asm/shared/msr.h>
 
+#include <linux/compiler_types.h>
 #include <linux/types.h>
-#include <linux/percpu.h>
 
 struct msr_info {
 	u32			msr_no;
@@ -256,6 +255,8 @@ int msr_set_bit(u32 msr, u8 bit);
 int msr_clear_bit(u32 msr, u8 bit);
 
 #ifdef CONFIG_SMP
+struct cpumask;
+
 int rdmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 *l, u32 *h);
 int wrmsr_on_cpu(unsigned int cpu, u32 msr_no, u32 l, u32 h);
 int rdmsrq_on_cpu(unsigned int cpu, u32 msr_no, u64 *q);
--- a/arch/x86/include/asm/pvclock.h
+++ b/arch/x86/include/asm/pvclock.h
@@ -2,6 +2,7 @@
 #ifndef _ASM_X86_PVCLOCK_H
 #define _ASM_X86_PVCLOCK_H
 
+#include <asm/barrier.h>
 #include <asm/clocksource.h>
 #include <asm/pvclock-abi.h>
 
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -5,8 +5,6 @@
 #include <linux/cpumask.h>
 #include <linux/thread_info.h>
 
-#include <asm/cpumask.h>
-
 DECLARE_PER_CPU_CACHE_HOT(int, cpu_number);
 
 DECLARE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_sibling_map);
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -11,13 +11,12 @@
 #define __ASM_VDSO_GETTIMEOFDAY_H
 
 #ifndef __ASSEMBLER__
-
+#include <clocksource/hyperv_timer.h>
 #include <uapi/linux/time.h>
+
 #include <asm/vgtod.h>
 #include <asm/unistd.h>
-#include <asm/msr.h>
 #include <asm/pvclock.h>
-#include <clocksource/hyperv_timer.h>
 #include <asm/vdso/sys_call.h>
 
 #define VDSO_HAS_TIME 1
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -48,6 +48,7 @@
 #include <linux/vmcore_info.h>
 
 #include <asm/fred.h>
+#include <asm/cpumask.h>
 #include <asm/cpu_device_id.h>
 #include <asm/processor.h>
 #include <asm/traps.h>
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -26,6 +26,7 @@
 #include <linux/sched/clock.h>
 #include <linux/kvm_types.h>
 
+#include <asm/cpumask.h>
 #include <asm/cpu_entry_area.h>
 #include <asm/traps.h>
 #include <asm/mach_traps.h>
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -70,6 +70,7 @@
 #include <asm/irq.h>
 #include <asm/realmode.h>
 #include <asm/cpu.h>
+#include <asm/cpumask.h>
 #include <asm/numa.h>
 #include <asm/tlbflush.h>
 #include <asm/mtrr.h>

[patch 03/38] x86/apm: Remove last LATCH usage

[Thomas Gleixner]

LATCH is a historical leftover and has been replaced with PIT_LATCH in all
other places a decade ago. Replace the last holdout and remove the
definition from jiffies.h.

This allows to remove the otherwise unused CLOCK_TICK_RATE define in the
next step.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/x86/kernel/apm_32.c |    4 ++--
 include/linux/jiffies.h  |    3 ---
 2 files changed, 2 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -1196,9 +1196,9 @@ static void reinit_timer(void)
 	/* set the clock to HZ */
 	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
 	udelay(10);
-	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
+	outb_p(PIT_LATCH & 0xff, PIT_CH0);	/* LSB */
 	udelay(10);
-	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
+	outb_p(PIT_LATCH >> 8, PIT_CH0);	/* MSB */
 	udelay(10);
 	raw_spin_unlock_irqrestore(&i8253_lock, flags);
 #endif
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -56,9 +56,6 @@
 #define SH_DIV(NOM,DEN,LSH) (   (((NOM) / (DEN)) << (LSH))              \
                              + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
 
-/* LATCH is used in the interval timer and ftape setup. */
-#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ)	/* For divider */
-
 extern void register_refined_jiffies(long clock_tick_rate);
 
 /* TICK_USEC is the time between ticks in usec */

[patch 04/38] x86: Use PIT_TICK_RATE instead of CLOCK_TICK_RATE

[Thomas Gleixner]

CLOCK_TICK_RATE is only used in x86 but defined all over the tree for no
reason with comments that it's scheduled for removal for more than a
decade.

Use PIT_TICK_RATE for registering refined jiffies to get rid of the last
dependency.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/x86/kernel/setup.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1268,7 +1268,7 @@ void __init setup_arch(char **cmdline_p)
 
 	mcheck_init();
 
-	register_refined_jiffies(CLOCK_TICK_RATE);
+	register_refined_jiffies(PIT_TICK_RATE);
 
 #ifdef CONFIG_EFI
 	if (efi_enabled(EFI_BOOT))

[patch 05/38] treewide: Remove CLOCK_TICK_RATE

[Thomas Gleixner]

This has been scheduled for removal more than a decade ago and the comments
related to it have been dutifully ignored. The last dependencies are gone.

Remove it along with various now empty asm/timex.h files.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/alpha/include/asm/timex.h      |    4 ----
 arch/arc/include/asm/timex.h        |   15 ---------------
 arch/arm/mach-omap1/Kconfig         |    2 +-
 arch/hexagon/include/asm/timex.h    |    3 ---
 arch/m68k/include/asm/timex.h       |   15 ---------------
 arch/microblaze/include/asm/timex.h |   13 -------------
 arch/mips/include/asm/timex.h       |    8 --------
 arch/openrisc/include/asm/timex.h   |    3 ---
 arch/parisc/include/asm/timex.h     |    2 --
 arch/powerpc/include/asm/timex.h    |    2 --
 arch/s390/include/asm/timex.h       |    2 --
 arch/sh/include/asm/timex.h         |   24 ------------------------
 arch/sparc/include/asm/timex.h      |    2 +-
 arch/sparc/include/asm/timex_32.h   |   14 --------------
 arch/sparc/include/asm/timex_64.h   |    2 --
 arch/um/include/asm/timex.h         |    9 ---------
 arch/x86/include/asm/timex.h        |    3 ---
 17 files changed, 2 insertions(+), 121 deletions(-)

--- a/arch/alpha/include/asm/timex.h
+++ b/arch/alpha/include/asm/timex.h
@@ -7,10 +7,6 @@
 #ifndef _ASMALPHA_TIMEX_H
 #define _ASMALPHA_TIMEX_H
 
-/* With only one or two oddballs, we use the RTC as the ticker, selecting
-   the 32.768kHz reference clock, which nicely divides down to our HZ.  */
-#define CLOCK_TICK_RATE	32768
-
 /*
  * Standard way to access the cycle counter.
  * Currently only used on SMP for scheduling.
--- a/arch/arc/include/asm/timex.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
- */
-
-#ifndef _ASM_ARC_TIMEX_H
-#define _ASM_ARC_TIMEX_H
-
-#define CLOCK_TICK_RATE	80000000 /* slated to be removed */
-
-#include <asm-generic/timex.h>
-
-/* XXX: get_cycles() to be implemented with RTSC insn */
-
-#endif /* _ASM_ARC_TIMEX_H */
--- a/arch/arm/mach-omap1/Kconfig
+++ b/arch/arm/mach-omap1/Kconfig
@@ -74,7 +74,7 @@ config OMAP_32K_TIMER
 	  currently only available for OMAP16XX, 24XX, 34XX, OMAP4/5 and DRA7XX.
 
 	  On OMAP2PLUS this value is only used for CONFIG_HZ and
-	  CLOCK_TICK_RATE compile time calculation.
+	  timer frequency compile time calculation.
 	  The actual timer selection is done in the board file
 	  through the (DT_)MACHINE_START structure.
 
--- a/arch/hexagon/include/asm/timex.h
+++ b/arch/hexagon/include/asm/timex.h
@@ -9,9 +9,6 @@
 #include <asm-generic/timex.h>
 #include <asm/hexagon_vm.h>
 
-/* Using TCX0 as our clock.  CLOCK_TICK_RATE scheduled to be removed. */
-#define CLOCK_TICK_RATE              19200
-
 #define ARCH_HAS_READ_CURRENT_TIMER
 
 static inline int read_current_timer(unsigned long *timer_val)
--- a/arch/m68k/include/asm/timex.h
+++ b/arch/m68k/include/asm/timex.h
@@ -7,21 +7,6 @@
 #ifndef _ASMm68K_TIMEX_H
 #define _ASMm68K_TIMEX_H
 
-#ifdef CONFIG_COLDFIRE
-/*
- * CLOCK_TICK_RATE should give the underlying frequency of the tick timer
- * to make ntp work best.  For Coldfires, that's the main clock.
- */
-#include <asm/coldfire.h>
-#define CLOCK_TICK_RATE	MCF_CLK
-#else
-/*
- * This default CLOCK_TICK_RATE is probably wrong for many 68k boards
- * Users of those boards will need to check and modify accordingly
- */
-#define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
-#endif
-
 typedef unsigned long cycles_t;
 
 static inline cycles_t get_cycles(void)
--- a/arch/microblaze/include/asm/timex.h
+++ /dev/null
@@ -1,13 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Copyright (C) 2006 Atmark Techno, Inc.
- */
-
-#ifndef _ASM_MICROBLAZE_TIMEX_H
-#define _ASM_MICROBLAZE_TIMEX_H
-
-#include <asm-generic/timex.h>
-
-#define CLOCK_TICK_RATE 1000 /* Timer input freq. */
-
-#endif /* _ASM_TIMEX_H */
--- a/arch/mips/include/asm/timex.h
+++ b/arch/mips/include/asm/timex.h
@@ -19,14 +19,6 @@
 #include <asm/cpu-type.h>
 
 /*
- * This is the clock rate of the i8253 PIT.  A MIPS system may not have
- * a PIT by the symbol is used all over the kernel including some APIs.
- * So keeping it defined to the number for the PIT is the only sane thing
- * for now.
- */
-#define CLOCK_TICK_RATE 1193182
-
-/*
  * Standard way to access the cycle counter.
  * Currently only used on SMP for scheduling.
  *
--- a/arch/openrisc/include/asm/timex.h
+++ b/arch/openrisc/include/asm/timex.h
@@ -25,9 +25,6 @@ static inline cycles_t get_cycles(void)
 }
 #define get_cycles get_cycles
 
-/* This isn't really used any more */
-#define CLOCK_TICK_RATE 1000
-
 #define ARCH_HAS_READ_CURRENT_TIMER
 
 #endif
--- a/arch/parisc/include/asm/timex.h
+++ b/arch/parisc/include/asm/timex.h
@@ -9,8 +9,6 @@
 
 #include <asm/special_insns.h>
 
-#define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
-
 typedef unsigned long cycles_t;
 
 static inline cycles_t get_cycles(void)
--- a/arch/powerpc/include/asm/timex.h
+++ b/arch/powerpc/include/asm/timex.h
@@ -11,8 +11,6 @@
 #include <asm/cputable.h>
 #include <asm/vdso/timebase.h>
 
-#define CLOCK_TICK_RATE	1024000 /* Underlying HZ */
-
 typedef unsigned long cycles_t;
 
 static inline cycles_t get_cycles(void)
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -177,8 +177,6 @@ static inline void local_tick_enable(uns
 	set_clock_comparator(get_lowcore()->clock_comparator);
 }
 
-#define CLOCK_TICK_RATE		1193180 /* Underlying HZ */
-
 typedef unsigned long cycles_t;
 
 static __always_inline unsigned long get_tod_clock(void)
--- a/arch/sh/include/asm/timex.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * linux/include/asm-sh/timex.h
- *
- * sh architecture timex specifications
- */
-#ifndef __ASM_SH_TIMEX_H
-#define __ASM_SH_TIMEX_H
-
-/*
- * Only parts using the legacy CPG code for their clock framework
- * implementation need to define their own Pclk value. If provided, this
- * can be used for accurately setting CLOCK_TICK_RATE, otherwise we
- * simply fall back on the i8253 PIT value.
- */
-#ifdef CONFIG_SH_PCLK_FREQ
-#define CLOCK_TICK_RATE		(CONFIG_SH_PCLK_FREQ / 4) /* Underlying HZ */
-#else
-#define CLOCK_TICK_RATE		1193180
-#endif
-
-#include <asm-generic/timex.h>
-
-#endif /* __ASM_SH_TIMEX_H */
--- a/arch/sparc/include/asm/timex.h
+++ b/arch/sparc/include/asm/timex.h
@@ -4,6 +4,6 @@
 #if defined(__sparc__) && defined(__arch64__)
 #include <asm/timex_64.h>
 #else
-#include <asm/timex_32.h>
+#include <asm-generic/timex.h>
 #endif
 #endif
--- a/arch/sparc/include/asm/timex_32.h
+++ /dev/null
@@ -1,14 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * linux/include/asm/timex.h
- *
- * sparc architecture timex specifications
- */
-#ifndef _ASMsparc_TIMEX_H
-#define _ASMsparc_TIMEX_H
-
-#define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
-
-#include <asm-generic/timex.h>
-
-#endif
--- a/arch/sparc/include/asm/timex_64.h
+++ b/arch/sparc/include/asm/timex_64.h
@@ -9,8 +9,6 @@
 
 #include <asm/timer.h>
 
-#define CLOCK_TICK_RATE	1193180 /* Underlying HZ */
-
 /* Getting on the cycle counter on sparc64. */
 typedef unsigned long cycles_t;
 #define get_cycles()	tick_ops->get_tick()
--- a/arch/um/include/asm/timex.h
+++ /dev/null
@@ -1,9 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __UM_TIMEX_H
-#define __UM_TIMEX_H
-
-#define CLOCK_TICK_RATE (HZ)
-
-#include <asm-generic/timex.h>
-
-#endif
--- a/arch/x86/include/asm/timex.h
+++ b/arch/x86/include/asm/timex.h
@@ -14,9 +14,6 @@ static inline unsigned long random_get_e
 }
 #define random_get_entropy random_get_entropy
 
-/* Assume we use the PIT time source for the clock tick */
-#define CLOCK_TICK_RATE		PIT_TICK_RATE
-
 #define ARCH_HAS_READ_CURRENT_TIMER
 
 #endif /* _ASM_X86_TIMEX_H */

[patch 06/38] calibrate: Rework delay timer calibration

[Thomas Gleixner]

The header define in asm/timex,h and the naming of the function to read the
delay timer are confusing at best.

Convert it to a config switch selected by the archictures, which provide
the functionality, and rename the function to delay_read_timer(), which
makes the purpose clear. Move the declaration to linux/delay.h where it
belongs.

Remove the resulting empty asm/timex.h files as well.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 arch/Kconfig                      |    3 +++
 arch/arm/Kconfig                  |    1 +
 arch/arm/include/asm/delay.h      |    1 -
 arch/arm/include/asm/timex.h      |    5 ++++-
 arch/arm/lib/delay.c              |   10 ++++------
 arch/hexagon/Kconfig              |    1 +
 arch/hexagon/include/asm/timex.h  |   20 --------------------
 arch/hexagon/kernel/time.c        |    8 +++++++-
 arch/openrisc/Kconfig             |    1 +
 arch/openrisc/include/asm/timex.h |    2 --
 arch/openrisc/lib/delay.c         |    9 ++++-----
 arch/riscv/Kconfig                |    1 +
 arch/riscv/include/asm/timex.h    |    8 --------
 arch/riscv/lib/delay.c            |    7 ++++++-
 arch/sparc/Kconfig                |    1 +
 arch/sparc/include/asm/timex_64.h |    2 --
 arch/sparc/kernel/time_64.c       |    4 ++--
 arch/x86/Kconfig                  |    1 +
 arch/x86/include/asm/timex.h      |    2 --
 arch/x86/lib/delay.c              |    8 +++-----
 include/asm-generic/timex.h       |    7 -------
 include/linux/delay.h             |    2 ++
 include/linux/timex.h             |    2 --
 init/calibrate.c                  |   19 +++++++++----------
 24 files changed, 50 insertions(+), 75 deletions(-)

--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -363,6 +363,9 @@ config ARCH_HAS_DMA_CLEAR_UNCACHED
 config ARCH_HAS_CPU_FINALIZE_INIT
 	bool
 
+config ARCH_HAS_DELAY_TIMER
+	bool
+
 # The architecture has a per-task state that includes the mm's PASID
 config ARCH_HAS_CPU_PASID
 	bool
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -11,6 +11,7 @@ config ARM
 	select ARCH_HAS_CPU_FINALIZE_INIT if MMU
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
+	select ARCH_HAS_DELAY_TIMER
 	select ARCH_HAS_DMA_ALLOC if MMU
 	select ARCH_HAS_DMA_OPS
 	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
--- a/arch/arm/include/asm/delay.h
+++ b/arch/arm/include/asm/delay.h
@@ -91,7 +91,6 @@ extern void __loop_udelay(unsigned long
 extern void __loop_const_udelay(unsigned long);
 
 /* Delay-loop timer registration. */
-#define ARCH_HAS_READ_CURRENT_TIMER
 extern void register_current_timer_delay(const struct delay_timer *timer);
 
 #endif /* __ASSEMBLY__ */
--- a/arch/arm/include/asm/timex.h
+++ b/arch/arm/include/asm/timex.h
@@ -10,7 +10,10 @@
 #define _ASMARM_TIMEX_H
 
 typedef unsigned long cycles_t;
-#define get_cycles()	({ cycles_t c; read_current_timer(&c) ? 0 : c; })
+// Temporary workaround
+bool delay_read_timer(unsigned long *t);
+
+#define get_cycles()	({ cycles_t c; delay_read_timer(&c) ? 0 : c; })
 #define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback())
 
 #endif
--- a/arch/arm/lib/delay.c
+++ b/arch/arm/lib/delay.c
@@ -12,7 +12,6 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/timex.h>
 
 /*
  * Default to the loop-based delay implementation.
@@ -27,15 +26,14 @@ static const struct delay_timer *delay_t
 static bool delay_calibrated;
 static u64 delay_res;
 
-int read_current_timer(unsigned long *timer_val)
+bool delay_read_timer(unsigned long *timer_val)
 {
 	if (!delay_timer)
-		return -ENXIO;
-
+		return false;
 	*timer_val = delay_timer->read_current_timer();
-	return 0;
+	return true;
 }
-EXPORT_SYMBOL_GPL(read_current_timer);
+EXPORT_SYMBOL_GPL(delay_read_timer);
 
 static inline u64 cyc_to_ns(u64 cyc, u32 mult, u32 shift)
 {
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -5,6 +5,7 @@ comment "Linux Kernel Configuration for
 config HEXAGON
 	def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_DELAY_TIMER
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_NO_PREEMPT
 	select ARCH_WANT_FRAME_POINTERS
--- a/arch/hexagon/include/asm/timex.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
- */
-
-#ifndef _ASM_TIMEX_H
-#define _ASM_TIMEX_H
-
-#include <asm-generic/timex.h>
-#include <asm/hexagon_vm.h>
-
-#define ARCH_HAS_READ_CURRENT_TIMER
-
-static inline int read_current_timer(unsigned long *timer_val)
-{
-	*timer_val = __vmgettime();
-	return 0;
-}
-
-#endif
--- a/arch/hexagon/kernel/time.c
+++ b/arch/hexagon/kernel/time.c
@@ -6,6 +6,7 @@
  */
 
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/clockchips.h>
 #include <linux/clocksource.h>
 #include <linux/interrupt.h>
@@ -17,7 +18,6 @@
 #include <linux/of_irq.h>
 #include <linux/module.h>
 
-#include <asm/delay.h>
 #include <asm/hexagon_vm.h>
 #include <asm/time.h>
 
@@ -231,3 +231,9 @@ void __udelay(unsigned long usecs)
 		cpu_relax(); /*  not sure how this improves readability  */
 }
 EXPORT_SYMBOL(__udelay);
+
+bool delay_read_timer(unsigned long *timer_val)
+{
+	*timer_val = __vmgettime();
+	return true;
+}
--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -7,6 +7,7 @@
 config OPENRISC
 	def_bool y
 	select ARCH_32BIT_OFF_T
+	select ARCH_HAS_DELAY_TIMER
 	select ARCH_HAS_DMA_SET_UNCACHED
 	select ARCH_HAS_DMA_CLEAR_UNCACHED
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
--- a/arch/openrisc/include/asm/timex.h
+++ b/arch/openrisc/include/asm/timex.h
@@ -25,6 +25,4 @@ static inline cycles_t get_cycles(void)
 }
 #define get_cycles get_cycles
 
-#define ARCH_HAS_READ_CURRENT_TIMER
-
 #endif
--- a/arch/openrisc/lib/delay.c
+++ b/arch/openrisc/lib/delay.c
@@ -13,18 +13,17 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/init.h>
-#include <linux/timex.h>
+
 #include <asm/param.h>
-#include <asm/delay.h>
-#include <asm/timex.h>
 #include <asm/processor.h>
 
-int read_current_timer(unsigned long *timer_value)
+bool delay_read_timer(unsigned long *timer_value)
 {
 	*timer_value = get_cycles();
-	return 0;
+	return true;
 }
 
 void __delay(unsigned long cycles)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -29,6 +29,7 @@ config RISCV
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEBUG_WX
+	select ARCH_HAS_DELAY_TIMER
 	select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE
 	select ARCH_HAS_FAST_MULTIPLIER
 	select ARCH_HAS_FORTIFY_SOURCE
--- a/arch/riscv/include/asm/timex.h
+++ b/arch/riscv/include/asm/timex.h
@@ -80,12 +80,4 @@ static inline u64 get_cycles64(void)
 	return ((u64)hi << 32) | lo;
 }
 #endif /* CONFIG_64BIT */
-
-#define ARCH_HAS_READ_CURRENT_TIMER
-static inline int read_current_timer(unsigned long *timer_val)
-{
-	*timer_val = get_cycles();
-	return 0;
-}
-
 #endif /* _ASM_RISCV_TIMEX_H */
--- a/arch/riscv/lib/delay.c
+++ b/arch/riscv/lib/delay.c
@@ -6,7 +6,6 @@
 #include <linux/delay.h>
 #include <linux/math.h>
 #include <linux/param.h>
-#include <linux/timex.h>
 #include <linux/types.h>
 #include <linux/export.h>
 
@@ -109,3 +108,9 @@ void ndelay(unsigned long nsecs)
 	__delay(ncycles >> NDELAY_SHIFT);
 }
 EXPORT_SYMBOL(ndelay);
+
+bool delay_read_timer(unsigned long *timer_val)
+{
+	*timer_val = get_cycles();
+	return true;
+}
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -70,6 +70,7 @@ config SPARC32
 config SPARC64
 	def_bool 64BIT
 	select ALTERNATE_USER_ADDRESS_SPACE
+	select ARCH_HAS_DELAY_TIMER
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_KRETPROBES
--- a/arch/sparc/include/asm/timex_64.h
+++ b/arch/sparc/include/asm/timex_64.h
@@ -13,6 +13,4 @@
 typedef unsigned long cycles_t;
 #define get_cycles()	tick_ops->get_tick()
 
-#define ARCH_HAS_READ_CURRENT_TIMER
-
 #endif
--- a/arch/sparc/kernel/time_64.c
+++ b/arch/sparc/kernel/time_64.c
@@ -894,8 +894,8 @@ unsigned long long sched_clock(void)
 	return ((get_tick() * quotient) >> SPARC64_NSEC_PER_CYC_SHIFT) - offset;
 }
 
-int read_current_timer(unsigned long *timer_val)
+bool delay_read_timer(unsigned long *timer_val)
 {
 	*timer_val = get_tick();
-	return 0;
+	return true;
 }
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -81,6 +81,7 @@ config X86
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
+	select ARCH_HAS_DELAY_TIMER
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_OPS			if GART_IOMMU || XEN
 	select ARCH_HAS_EARLY_DEBUG		if KGDB
--- a/arch/x86/include/asm/timex.h
+++ b/arch/x86/include/asm/timex.h
@@ -14,6 +14,4 @@ static inline unsigned long random_get_e
 }
 #define random_get_entropy random_get_entropy
 
-#define ARCH_HAS_READ_CURRENT_TIMER
-
 #endif /* _ASM_X86_TIMEX_H */
--- a/arch/x86/lib/delay.c
+++ b/arch/x86/lib/delay.c
@@ -14,12 +14,10 @@
 
 #include <linux/export.h>
 #include <linux/sched.h>
-#include <linux/timex.h>
 #include <linux/preempt.h>
 #include <linux/delay.h>
 
 #include <asm/processor.h>
-#include <asm/delay.h>
 #include <asm/timer.h>
 #include <asm/mwait.h>
 
@@ -189,13 +187,13 @@ void use_mwaitx_delay(void)
 	delay_fn = delay_halt;
 }
 
-int read_current_timer(unsigned long *timer_val)
+bool delay_read_timer(unsigned long *timer_val)
 {
 	if (delay_fn == delay_tsc) {
 		*timer_val = rdtsc();
-		return 0;
+		return true;
 	}
-	return -1;
+	return false;
 }
 
 void __delay(unsigned long loops)
--- a/include/asm-generic/timex.h
+++ b/include/asm-generic/timex.h
@@ -13,11 +13,4 @@ static inline cycles_t get_cycles(void)
 }
 #endif
 
-/*
- * Architectures are encouraged to implement read_current_timer
- * and define this in order to avoid the expensive delay loop
- * calibration during boot.
- */
-#undef ARCH_HAS_READ_CURRENT_TIMER
-
 #endif /* __ASM_GENERIC_TIMEX_H */
--- a/include/linux/delay.h
+++ b/include/linux/delay.h
@@ -17,6 +17,8 @@ extern unsigned long loops_per_jiffy;
 
 #include <asm/delay.h>
 
+bool delay_read_timer(unsigned long *t);
+
 /*
  * Using udelay() for intervals greater than a few milliseconds can
  * risk overflow for high loops_per_jiffy (high bogomips) machines. The
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -156,8 +156,6 @@ extern int do_clock_adjtime(const clocki
 
 extern void hardpps(const struct timespec64 *, const struct timespec64 *);
 
-int read_current_timer(unsigned long *timer_val);
-
 /* The clock frequency of the i8253/i8254 PIT */
 #define PIT_TICK_RATE 1193182ul
 
--- a/init/calibrate.c
+++ b/init/calibrate.c
@@ -13,7 +13,6 @@
 #include <linux/printk.h>
 #include <linux/smp.h>
 #include <linux/stddef.h>
-#include <linux/timex.h>
 
 unsigned long lpj_fine;
 unsigned long preset_lpj;
@@ -25,9 +24,9 @@ static int __init lpj_setup(char *str)
 
 __setup("lpj=", lpj_setup);
 
-#ifdef ARCH_HAS_READ_CURRENT_TIMER
+#ifdef CONFIG_ARCH_HAS_DELAY_TIMER
 
-/* This routine uses the read_current_timer() routine and gets the
+/* This routine uses the delay_read_timer() routine and gets the
  * loops per jiffy directly, instead of guessing it using delay().
  * Also, this code tries to handle non-maskable asynchronous events
  * (like SMIs)
@@ -48,13 +47,13 @@ static unsigned long calibrate_delay_dir
 	int min = -1;
 	int i;
 
-	if (read_current_timer(&pre_start) < 0 )
+	if (!delay_read_timer(&pre_start))
 		return 0;
 
 	/*
 	 * A simple loop like
 	 *	while ( jiffies < start_jiffies+1)
-	 *		start = read_current_timer();
+	 *		start = delay_read_timer();
 	 * will not do. As we don't really know whether jiffy switch
 	 * happened first or timer_value was read first. And some asynchronous
 	 * event can happen between these two events introducing errors in lpj.
@@ -72,22 +71,22 @@ static unsigned long calibrate_delay_dir
 
 	for (i = 0; i < MAX_DIRECT_CALIBRATION_RETRIES; i++) {
 		pre_start = 0;
-		read_current_timer(&start);
+		delay_read_timer(&start);
 		start_jiffies = jiffies;
 		while (time_before_eq(jiffies, start_jiffies + 1)) {
 			pre_start = start;
-			read_current_timer(&start);
+			delay_read_timer(&start);
 		}
-		read_current_timer(&post_start);
+		delay_read_timer(&post_start);
 
 		pre_end = 0;
 		end = post_start;
 		while (time_before_eq(jiffies, start_jiffies + 1 +
 					       DELAY_CALIBRATION_TICKS)) {
 			pre_end = end;
-			read_current_timer(&end);
+			delay_read_timer(&end);
 		}
-		read_current_timer(&post_end);
+		delay_read_timer(&post_end);
 
 		timer_rate_max = (post_end - pre_start) /
 					DELAY_CALIBRATION_TICKS;

[patch 07/38] treewide: Consolidate cycles_t

[Thomas Gleixner]

Most architectures define cycles_t as unsigned long execpt:

 - x86 requires it to be 64-bit independent of the 32-bit/64-bit build.

 - parisc and mips define it as unsigned int

   parisc has no real reason to do so as there are only a few usage sites
   which either expand it to a 64-bit value or utilize only the lower
   32bits.

   mips has no real requirement either.

Move the typedef to types.h and provide a config switch to enforce the
64-bit type for x86.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/Kconfig                       |    4 ++++
 arch/alpha/include/asm/timex.h     |    3 ---
 arch/arm/include/asm/timex.h       |    1 -
 arch/loongarch/include/asm/timex.h |    2 --
 arch/m68k/include/asm/timex.h      |    2 --
 arch/mips/include/asm/timex.h      |    2 --
 arch/nios2/include/asm/timex.h     |    2 --
 arch/parisc/include/asm/timex.h    |    2 --
 arch/powerpc/include/asm/timex.h   |    4 +---
 arch/riscv/include/asm/timex.h     |    2 --
 arch/s390/include/asm/timex.h      |    2 --
 arch/sparc/include/asm/timex_64.h  |    1 -
 arch/x86/Kconfig                   |    1 +
 arch/x86/include/asm/tsc.h         |    2 --
 include/asm-generic/timex.h        |    1 -
 include/linux/types.h              |    6 ++++++
 16 files changed, 12 insertions(+), 25 deletions(-)

--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -360,6 +360,10 @@ config ARCH_HAS_DMA_SET_UNCACHED
 config ARCH_HAS_DMA_CLEAR_UNCACHED
 	bool
 
+# cycles_t is always 64bit wide
+config ARCH_HAS_CYCLES_T_64
+	bool
+
 config ARCH_HAS_CPU_FINALIZE_INIT
 	bool
 
--- a/arch/alpha/include/asm/timex.h
+++ b/arch/alpha/include/asm/timex.h
@@ -15,9 +15,6 @@
  * But this only means we'll force a reschedule every 8 seconds or so,
  * which isn't an evil thing.
  */
-
-typedef unsigned int cycles_t;
-
 static inline cycles_t get_cycles (void)
 {
 	cycles_t ret;
--- a/arch/arm/include/asm/timex.h
+++ b/arch/arm/include/asm/timex.h
@@ -9,7 +9,6 @@
 #ifndef _ASMARM_TIMEX_H
 #define _ASMARM_TIMEX_H
 
-typedef unsigned long cycles_t;
 // Temporary workaround
 bool delay_read_timer(unsigned long *t);
 
--- a/arch/loongarch/include/asm/timex.h
+++ b/arch/loongarch/include/asm/timex.h
@@ -12,8 +12,6 @@
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
 
-typedef unsigned long cycles_t;
-
 #define get_cycles get_cycles
 
 static inline cycles_t get_cycles(void)
--- a/arch/m68k/include/asm/timex.h
+++ b/arch/m68k/include/asm/timex.h
@@ -7,8 +7,6 @@
 #ifndef _ASMm68K_TIMEX_H
 #define _ASMm68K_TIMEX_H
 
-typedef unsigned long cycles_t;
-
 static inline cycles_t get_cycles(void)
 {
 	return 0;
--- a/arch/mips/include/asm/timex.h
+++ b/arch/mips/include/asm/timex.h
@@ -29,8 +29,6 @@
  * We know that all SMP capable CPUs have cycle counters.
  */
 
-typedef unsigned int cycles_t;
-
 /*
  * On R4000/R4400 an erratum exists such that if the cycle counter is
  * read in the exact moment that it is matching the compare register,
--- a/arch/nios2/include/asm/timex.h
+++ b/arch/nios2/include/asm/timex.h
@@ -5,8 +5,6 @@
 #ifndef _ASM_NIOS2_TIMEX_H
 #define _ASM_NIOS2_TIMEX_H
 
-typedef unsigned long cycles_t;
-
 extern cycles_t get_cycles(void);
 #define get_cycles get_cycles
 
--- a/arch/parisc/include/asm/timex.h
+++ b/arch/parisc/include/asm/timex.h
@@ -9,8 +9,6 @@
 
 #include <asm/special_insns.h>
 
-typedef unsigned long cycles_t;
-
 static inline cycles_t get_cycles(void)
 {
 	return mfctl(16);
--- a/arch/powerpc/include/asm/timex.h
+++ b/arch/powerpc/include/asm/timex.h
@@ -11,9 +11,7 @@
 #include <asm/cputable.h>
 #include <asm/vdso/timebase.h>
 
-typedef unsigned long cycles_t;
-
-static inline cycles_t get_cycles(void)
+ostatic inline cycles_t get_cycles(void)
 {
 	return mftb();
 }
--- a/arch/riscv/include/asm/timex.h
+++ b/arch/riscv/include/asm/timex.h
@@ -8,8 +8,6 @@
 
 #include <asm/csr.h>
 
-typedef unsigned long cycles_t;
-
 #ifdef CONFIG_RISCV_M_MODE
 
 #include <asm/clint.h>
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -177,8 +177,6 @@ static inline void local_tick_enable(uns
 	set_clock_comparator(get_lowcore()->clock_comparator);
 }
 
-typedef unsigned long cycles_t;
-
 static __always_inline unsigned long get_tod_clock(void)
 {
 	union tod_clock clk;
--- a/arch/sparc/include/asm/timex_64.h
+++ b/arch/sparc/include/asm/timex_64.h
@@ -10,7 +10,6 @@
 #include <asm/timer.h>
 
 /* Getting on the cycle counter on sparc64. */
-typedef unsigned long cycles_t;
 #define get_cycles()	tick_ops->get_tick()
 
 #endif
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -79,6 +79,7 @@ config X86
 	select ARCH_HAS_CPU_FINALIZE_INIT
 	select ARCH_HAS_CPU_PASID		if IOMMU_SVA
 	select ARCH_HAS_CURRENT_STACK_POINTER
+	select ARCH_HAS_CYCLES_T_64
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
 	select ARCH_HAS_DELAY_TIMER
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -67,8 +67,6 @@ static __always_inline u64 rdtsc_ordered
 /*
  * Standard way to access the cycle counter.
  */
-typedef unsigned long long cycles_t;
-
 extern unsigned int cpu_khz;
 extern unsigned int tsc_khz;
 
--- a/include/asm-generic/timex.h
+++ b/include/asm-generic/timex.h
@@ -5,7 +5,6 @@
 /*
  * If you have a cycle counter, return the value here.
  */
-typedef unsigned long cycles_t;
 #ifndef get_cycles
 static inline cycles_t get_cycles(void)
 {
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -270,5 +270,11 @@ struct rcuwait {
 	struct task_struct __rcu *task;
 };
 
+#ifdef CONFIG_ARCH_HAS_CYCLES_T_64
+typedef unsigned long long	cycles_t;
+#else
+typedef unsigned long		cycles_t;
+#endif
+
 #endif /*  __ASSEMBLY__ */
 #endif /* _LINUX_TYPES_H */

[patch 08/38] x86/tsc: Use rdtsc() instead of get_cycles()

[Thomas Gleixner]

This code knows that TSC is available so there is no point to use the TSC
feature guarded get_cycles().

No functional change.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/x86/kernel/tsc.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -371,12 +371,12 @@ static u64 tsc_read_refs(u64 *p, int hpe
 	int i;
 
 	for (i = 0; i < MAX_RETRIES; i++) {
-		t1 = get_cycles();
+		t1 = rdtsc();
 		if (hpet)
 			*p = hpet_readl(HPET_COUNTER) & 0xFFFFFFFF;
 		else
 			*p = acpi_pm_read_early();
-		t2 = get_cycles();
+		t2 = rdtsc();
 		if ((t2 - t1) < thresh)
 			return t2;
 	}
@@ -468,13 +468,13 @@ static unsigned long pit_calibrate_tsc(u
 	outb(latch & 0xff, 0x42);
 	outb(latch >> 8, 0x42);
 
-	tsc = t1 = t2 = get_cycles();
+	tsc = t1 = t2 = rdtsc();
 
 	pitcnt = 0;
 	tscmax = 0;
 	tscmin = ULONG_MAX;
 	while ((inb(0x61) & 0x20) == 0) {
-		t2 = get_cycles();
+		t2 = rdtsc();
 		delta = t2 - tsc;
 		tsc = t2;
 		if ((unsigned long) delta < tscmin)
@@ -553,9 +553,9 @@ static inline int pit_expect_msb(unsigne
 		if (!pit_verify_msb(val))
 			break;
 		prev_tsc = tsc;
-		tsc = get_cycles();
+		tsc = rdtsc();
 	}
-	*deltap = get_cycles() - prev_tsc;
+	*deltap = rdtsc() - prev_tsc;
 	*tscp = tsc;
 
 	/*

[patch 09/38] iommu/vt-d: Use sched_clock() instead of get_cycles()

[Thomas Gleixner]

Calculating the timeout from get_cycles() is a historical leftover without
any functional requirement.

Use ktime_get() instead.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: x86@kernel.org
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: iommu@lists.linux.dev
---
 arch/x86/include/asm/iommu.h |    3 ---
 drivers/iommu/intel/dmar.c   |    4 ++--
 drivers/iommu/intel/iommu.h  |    8 ++++++--
 3 files changed, 8 insertions(+), 7 deletions(-)

--- a/arch/x86/include/asm/iommu.h
+++ b/arch/x86/include/asm/iommu.h
@@ -18,9 +18,6 @@ extern bool x86_swiotlb_enable;
 #define x86_swiotlb_enable false
 #endif
 
-/* 10 seconds */
-#define DMAR_OPERATION_TIMEOUT ((cycles_t) tsc_khz*10*1000)
-
 static inline int __init
 arch_rmrr_sanity_check(struct acpi_dmar_reserved_memory *rmrr)
 {
--- a/drivers/iommu/intel/dmar.c
+++ b/drivers/iommu/intel/dmar.c
@@ -1606,9 +1606,9 @@ void qi_flush_pasid_cache(struct intel_i
  */
 void dmar_disable_qi(struct intel_iommu *iommu)
 {
+	ktime_t start_time = ktime_get();
 	unsigned long flags;
 	u32 sts;
-	cycles_t start_time = get_cycles();
 
 	if (!ecap_qis(iommu->ecap))
 		return;
@@ -1624,7 +1624,7 @@ void dmar_disable_qi(struct intel_iommu
 	 */
 	while ((readl(iommu->reg + DMAR_IQT_REG) !=
 		readl(iommu->reg + DMAR_IQH_REG)) &&
-		(DMAR_OPERATION_TIMEOUT > (get_cycles() - start_time)))
+	       (DMAR_OPERATION_TIMEOUT > (ktime_get() - start_time)))
 		cpu_relax();
 
 	iommu->gcmd &= ~DMA_GCMD_QIE;
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -23,6 +23,7 @@
 #include <linux/xarray.h>
 #include <linux/perf_event.h>
 #include <linux/pci.h>
+#include <linux/timekeeping.h>
 #include <linux/generic_pt/iommu.h>
 
 #include <asm/iommu.h>
@@ -360,14 +361,17 @@
 /* PERFINTRSTS_REG */
 #define DMA_PERFINTRSTS_PIS	((u32)1)
 
+#define DMAR_OPERATION_TIMEOUT  (((ktime_t)10) * NSEC_PER_SEC)
+
 #define IOMMU_WAIT_OP(iommu, offset, op, cond, sts)			\
 do {									\
-	cycles_t start_time = get_cycles();				\
+	ktime_t start_time = ktime_get();				\
+									\
 	while (1) {							\
 		sts = op(iommu->reg + offset);				\
 		if (cond)						\
 			break;						\
-		if (DMAR_OPERATION_TIMEOUT < (get_cycles() - start_time))\
+		if (DMAR_OPERATION_TIMEOUT < (ktime_get() - start_time))\
 			panic("DMAR hardware is malfunctioning\n");	\
 		cpu_relax();						\
 	}								\

Re: [patch 09/38] iommu/vt-d: Use sched_clock() instead of get_cycles()

[Baolu Lu]

On 4/10/2026 8:19 PM, Thomas Gleixner wrote:
> Calculating the timeout from get_cycles() is a historical leftover without
> any functional requirement.
> 
> Use ktime_get() instead.

The subject line says "Use sched_clock() ...", but the implementation
actually uses ktime_get(). Is it a typo or anything I misunderstood?

Other parts look good to me,

Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>

> 
> Signed-off-by: Thomas Gleixner<tglx@kernel.org>
> Cc:x86@kernel.org
> Cc: Lu Baolu<baolu.lu@linux.intel.com>
> Cc:iommu@lists.linux.dev
> ---
>   arch/x86/include/asm/iommu.h |    3 ---
>   drivers/iommu/intel/dmar.c   |    4 ++--
>   drivers/iommu/intel/iommu.h  |    8 ++++++--
>   3 files changed, 8 insertions(+), 7 deletions(-)

Thanks,
baolu

Re: [patch 09/38] iommu/vt-d: Use sched_clock() instead of get_cycles()

[Thomas Gleixner]

On Fri, Apr 10 2026 at 21:45, Baolu Lu wrote:
> On 4/10/2026 8:19 PM, Thomas Gleixner wrote:
>> Calculating the timeout from get_cycles() is a historical leftover without
>> any functional requirement.
>> 
>> Use ktime_get() instead.
>
> The subject line says "Use sched_clock() ...", but the implementation
> actually uses ktime_get(). Is it a typo or anything I misunderstood?

Indeed. Leftover from an earlier version.

Thanks,

        tglx

[patch 10/38] arcnet: Remove function timing code

[Thomas Gleixner]

ARCNET is a museums piece and the function timing can be done with
ftrace. Remove the cruft.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Michael Grzeschik <m.grzeschik@pengutronix.de>
Cc: netdev@vger.kernel.org
---
 drivers/net/arcnet/arc-rimi.c  |    4 ++--
 drivers/net/arcnet/arcdevice.h |   20 +-------------------
 drivers/net/arcnet/com20020.c  |    6 ++----
 drivers/net/arcnet/com90io.c   |    6 ++----
 drivers/net/arcnet/com90xx.c   |    4 ++--
 5 files changed, 9 insertions(+), 31 deletions(-)

--- a/drivers/net/arcnet/arc-rimi.c
+++ b/drivers/net/arcnet/arc-rimi.c
@@ -291,7 +291,7 @@ static void arcrimi_copy_to_card(struct
 	struct arcnet_local *lp = netdev_priv(dev);
 	void __iomem *memaddr = lp->mem_start + 0x800 + bufnum * 512 + offset;
 
-	TIME(dev, "memcpy_toio", count, memcpy_toio(memaddr, buf, count));
+	memcpy_toio(memaddr, buf, count);
 }
 
 static void arcrimi_copy_from_card(struct net_device *dev, int bufnum,
@@ -300,7 +300,7 @@ static void arcrimi_copy_from_card(struc
 	struct arcnet_local *lp = netdev_priv(dev);
 	void __iomem *memaddr = lp->mem_start + 0x800 + bufnum * 512 + offset;
 
-	TIME(dev, "memcpy_fromio", count, memcpy_fromio(buf, memaddr, count));
+	memcpy_fromio(buf, memaddr, count);
 }
 
 static int node;
--- a/drivers/net/arcnet/arcdevice.h
+++ b/drivers/net/arcnet/arcdevice.h
@@ -11,7 +11,6 @@
 #ifndef _LINUX_ARCDEVICE_H
 #define _LINUX_ARCDEVICE_H
 
-#include <asm/timex.h>
 #include <linux/if_arcnet.h>
 
 #ifdef __KERNEL__
@@ -62,7 +61,7 @@
 #define D_RX		512	/* show rx packets                        */
 #define D_SKB		1024	/* show skb's                             */
 #define D_SKB_SIZE	2048	/* show skb sizes			  */
-#define D_TIMING	4096	/* show time needed to copy buffers to card */
+#define D_TIMING	4096	/* Not longer supported. Use tracing instead */
 #define D_DEBUG         8192    /* Very detailed debug line for line */
 
 #ifndef ARCNET_DEBUG_MAX
@@ -95,23 +94,6 @@ do {									\
 		pr_cont(fmt, ##__VA_ARGS__);				\
 } while (0)
 
-/* see how long a function call takes to run, expressed in CPU cycles */
-#define TIME(dev, name, bytes, call)					\
-do {									\
-	if (BUGLVL(D_TIMING)) {						\
-		unsigned long _x, _y;					\
-		_x = get_cycles();					\
-		call;							\
-		_y = get_cycles();					\
-		arc_printk(D_TIMING, dev,				\
-			   "%s: %d bytes in %lu cycles == %lu Kbytes/100Mcycle\n", \
-			   name, bytes, _y - _x,			\
-			   100000000 / 1024 * bytes / (_y - _x + 1));	\
-	} else {							\
-		call;							\
-	}								\
-} while (0)
-
 /*
  * Time needed to reset the card - in ms (milliseconds).  This works on my
  * SMC PC100.  I can't find a reference that tells me just how long I
--- a/drivers/net/arcnet/com20020.c
+++ b/drivers/net/arcnet/com20020.c
@@ -70,8 +70,7 @@ static void com20020_copy_from_card(stru
 	arcnet_outb(ofs & 0xff, ioaddr, COM20020_REG_W_ADDR_LO);
 
 	/* copy the data */
-	TIME(dev, "insb", count,
-	     arcnet_insb(ioaddr, COM20020_REG_RW_MEMDATA, buf, count));
+	arcnet_insb(ioaddr, COM20020_REG_RW_MEMDATA, buf, count);
 }
 
 static void com20020_copy_to_card(struct net_device *dev, int bufnum,
@@ -84,8 +83,7 @@ static void com20020_copy_to_card(struct
 	arcnet_outb(ofs & 0xff, ioaddr, COM20020_REG_W_ADDR_LO);
 
 	/* copy the data */
-	TIME(dev, "outsb", count,
-	     arcnet_outsb(ioaddr, COM20020_REG_RW_MEMDATA, buf, count));
+	arcnet_outsb(ioaddr, COM20020_REG_RW_MEMDATA, buf, count);
 }
 
 /* Reset the card and check some basic stuff during the detection stage. */
--- a/drivers/net/arcnet/com90io.c
+++ b/drivers/net/arcnet/com90io.c
@@ -332,15 +332,13 @@ static void com90io_setmask(struct net_d
 static void com90io_copy_to_card(struct net_device *dev, int bufnum,
 				 int offset, void *buf, int count)
 {
-	TIME(dev, "put_whole_buffer", count,
-	     put_whole_buffer(dev, bufnum * 512 + offset, count, buf));
+	put_whole_buffer(dev, bufnum * 512 + offset, count, buf);
 }
 
 static void com90io_copy_from_card(struct net_device *dev, int bufnum,
 				   int offset, void *buf, int count)
 {
-	TIME(dev, "get_whole_buffer", count,
-	     get_whole_buffer(dev, bufnum * 512 + offset, count, buf));
+	get_whole_buffer(dev, bufnum * 512 + offset, count, buf);
 }
 
 static int io;			/* use the insmod io= irq= shmem= options */
--- a/drivers/net/arcnet/com90xx.c
+++ b/drivers/net/arcnet/com90xx.c
@@ -633,7 +633,7 @@ static void com90xx_copy_to_card(struct
 	struct arcnet_local *lp = netdev_priv(dev);
 	void __iomem *memaddr = lp->mem_start + bufnum * 512 + offset;
 
-	TIME(dev, "memcpy_toio", count, memcpy_toio(memaddr, buf, count));
+	memcpy_toio(memaddr, buf, count);
 }
 
 static void com90xx_copy_from_card(struct net_device *dev, int bufnum,
@@ -642,7 +642,7 @@ static void com90xx_copy_from_card(struc
 	struct arcnet_local *lp = netdev_priv(dev);
 	void __iomem *memaddr = lp->mem_start + bufnum * 512 + offset;
 
-	TIME(dev, "memcpy_fromio", count, memcpy_fromio(buf, memaddr, count));
+	memcpy_fromio(buf, memaddr, count);
 }
 
 MODULE_DESCRIPTION("ARCnet COM90xx normal chipset driver");

[patch 11/38] misc: sgi-gru: Remove get_cycles() [ab]use

[Thomas Gleixner]

Calculating a timeout from get_cycles() is a historical leftover without
any functional requirement.

Use ktime_get() instead.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 drivers/misc/sgi-gru/gruhandles.c   |   20 ++++++++------------
 drivers/misc/sgi-gru/grukservices.c |    3 ++-
 drivers/misc/sgi-gru/grutlbpurge.c  |    5 ++---
 3 files changed, 12 insertions(+), 16 deletions(-)

--- a/drivers/misc/sgi-gru/gruhandles.c
+++ b/drivers/misc/sgi-gru/gruhandles.c
@@ -6,26 +6,22 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/timekeeping.h>
 #include "gru.h"
 #include "grulib.h"
 #include "grutables.h"
 
-/* 10 sec */
 #include <linux/sync_core.h>
-#include <asm/tsc.h>
-#define GRU_OPERATION_TIMEOUT	((cycles_t) tsc_khz*10*1000)
-#define CLKS2NSEC(c)		((c) * 1000000 / tsc_khz)
+
+#define GRU_OPERATION_TIMEOUT_NSEC	(((ktime_t)10 * NSEC_PER_SEC))
 
 /* Extract the status field from a kernel handle */
 #define GET_MSEG_HANDLE_STATUS(h)	(((*(unsigned long *)(h)) >> 16) & 3)
 
 struct mcs_op_statistic mcs_op_statistics[mcsop_last];
 
-static void update_mcs_stats(enum mcs_op op, unsigned long clks)
+static void update_mcs_stats(enum mcs_op op, unsigned long nsec)
 {
-	unsigned long nsec;
-
-	nsec = CLKS2NSEC(clks);
 	atomic_long_inc(&mcs_op_statistics[op].count);
 	atomic_long_add(nsec, &mcs_op_statistics[op].total);
 	if (mcs_op_statistics[op].max < nsec)
@@ -58,21 +54,21 @@ static void report_instruction_timeout(v
 
 static int wait_instruction_complete(void *h, enum mcs_op opc)
 {
+	ktime_t start_time = ktime_get();
 	int status;
-	unsigned long start_time = get_cycles();
 
 	while (1) {
 		cpu_relax();
 		status = GET_MSEG_HANDLE_STATUS(h);
 		if (status != CCHSTATUS_ACTIVE)
 			break;
-		if (GRU_OPERATION_TIMEOUT < (get_cycles() - start_time)) {
+		if (GRU_OP_TIMEOUT_NSEC < (ktime_get() - start_time)) {
 			report_instruction_timeout(h);
-			start_time = get_cycles();
+			start_time = ktime_get();
 		}
 	}
 	if (gru_options & OPT_STATS)
-		update_mcs_stats(opc, get_cycles() - start_time);
+		update_mcs_stats(opc, (unsigned long)(ktime_get() - start_time));
 	return status;
 }
 
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -20,6 +20,7 @@
 #include <linux/uaccess.h>
 #include <linux/delay.h>
 #include <linux/export.h>
+#include <linux/random.h>
 #include <asm/io_apic.h>
 #include "gru.h"
 #include "grulib.h"
@@ -1106,7 +1107,7 @@ static int quicktest3(unsigned long arg)
 	int ret = 0;
 
 	memset(buf2, 0, sizeof(buf2));
-	memset(buf1, get_cycles() & 255, sizeof(buf1));
+	memset(buf1, get_random_u32() & 255, sizeof(buf1));
 	gru_copy_gpa(uv_gpa(buf2), uv_gpa(buf1), BUFSIZE);
 	if (memcmp(buf1, buf2, BUFSIZE)) {
 		printk(KERN_DEBUG "GRU:%d quicktest3 error\n", smp_processor_id());
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -22,13 +22,12 @@
 #include <linux/delay.h>
 #include <linux/timex.h>
 #include <linux/srcu.h>
+#include <linux/random.h>
 #include <asm/processor.h>
 #include "gru.h"
 #include "grutables.h"
 #include <asm/uv/uv_hub.h>
 
-#define gru_random()	get_cycles()
-
 /* ---------------------------------- TLB Invalidation functions --------
  * get_tgh_handle
  *
@@ -49,7 +48,7 @@ static inline int get_off_blade_tgh(stru
 	int n;
 
 	n = GRU_NUM_TGH - gru->gs_tgh_first_remote;
-	n = gru_random() % n;
+	n = get_random_u32() % n;
 	n += gru->gs_tgh_first_remote;
 	return n;
 }

[patch 12/38] wifi: wil6210: Replace get_cyles() usage

[Thomas Gleixner]

There is no reason why this debug code requires to use get_cycles() for
timing purposes.

Use ktime_get() instead.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: linux-wireless@vger.kernel.org
---
 drivers/net/wireless/ath/wil6210/debugfs.c   |    2 +-
 drivers/net/wireless/ath/wil6210/txrx.c      |    6 +++---
 drivers/net/wireless/ath/wil6210/txrx_edma.c |    4 ++--
 drivers/net/wireless/ath/wil6210/wil6210.h   |    3 ++-
 4 files changed, 8 insertions(+), 7 deletions(-)

--- a/drivers/net/wireless/ath/wil6210/debugfs.c
+++ b/drivers/net/wireless/ath/wil6210/debugfs.c
@@ -151,7 +151,7 @@ static int ring_show(struct seq_file *s,
 			char name[10];
 			char sidle[10];
 			/* performance monitoring */
-			cycles_t now = get_cycles();
+			ktime_t now = ktime_get();
 			uint64_t idle = txdata->idle * 100;
 			uint64_t total = now - txdata->begin;
 
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -1976,7 +1976,7 @@ static int __wil_tx_vring_tso(struct wil
 	used = wil_ring_used_tx(vring);
 	if (wil_val_in_range(wil->ring_idle_trsh,
 			     used, used + descs_used)) {
-		txdata->idle += get_cycles() - txdata->last_idle;
+		txdata->idle += ktime_get() - txdata->last_idle;
 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
 			     vring_index, used, used + descs_used);
 	}
@@ -2129,7 +2129,7 @@ static int __wil_tx_ring(struct wil6210_
 	used = wil_ring_used_tx(ring);
 	if (wil_val_in_range(wil->ring_idle_trsh,
 			     used, used + nr_frags + 1)) {
-		txdata->idle += get_cycles() - txdata->last_idle;
+		txdata->idle += ktime_get() - txdata->last_idle;
 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
 			     ring_index, used, used + nr_frags + 1);
 	}
@@ -2531,7 +2531,7 @@ int wil_tx_complete(struct wil6210_vif *
 			     used_new, used_before_complete)) {
 		wil_dbg_txrx(wil, "Ring[%2d] idle %d -> %d\n",
 			     ringid, used_before_complete, used_new);
-		txdata->last_idle = get_cycles();
+		txdata->last_idle = ktime_get();
 	}
 
 	/* shall we wake net queues? */
--- a/drivers/net/wireless/ath/wil6210/txrx_edma.c
+++ b/drivers/net/wireless/ath/wil6210/txrx_edma.c
@@ -1286,7 +1286,7 @@ int wil_tx_sring_handler(struct wil6210_
 				     used_new, used_before_complete)) {
 			wil_dbg_txrx(wil, "Ring[%2d] idle %d -> %d\n",
 				     ring_id, used_before_complete, used_new);
-			txdata->last_idle = get_cycles();
+			txdata->last_idle = ktime_get();
 		}
 
 again:
@@ -1499,7 +1499,7 @@ static int __wil_tx_ring_tso_edma(struct
 	used = wil_ring_used_tx(ring);
 	if (wil_val_in_range(wil->ring_idle_trsh,
 			     used, used + descs_used)) {
-		txdata->idle += get_cycles() - txdata->last_idle;
+		txdata->idle += ktime_get() - txdata->last_idle;
 		wil_dbg_txrx(wil,  "Ring[%2d] not idle %d -> %d\n",
 			     ring_index, used, used + descs_used);
 	}
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -14,6 +14,7 @@
 #include <linux/timex.h>
 #include <linux/types.h>
 #include <linux/irqreturn.h>
+#include <linux/timekeeping.h>
 #include "wmi.h"
 #include "wil_platform.h"
 #include "fw.h"
@@ -632,7 +633,7 @@ struct wil_txrx_ops {
 struct wil_ring_tx_data {
 	bool dot1x_open;
 	int enabled;
-	cycles_t idle, last_idle, begin;
+	ktime_t idle, last_idle, begin;
 	u8 agg_wsize; /* agreed aggregation window, 0 - no agg */
 	u16 agg_timeout;
 	u8 agg_amsdu;

[patch 13/38] crypto: tcrypt: Replace get_cycles() with ktime_get()

[Thomas Gleixner]

get_cycles() is the historical access to a fine grained time source, but it
is a suboptimal choice for two reasons:

   - get_cycles() is not guaranteed to be supported and functional on all
     systems/platforms. If not supported or not functional it returns 0,
     which makes benchmarking moot.

   - get_cycles() returns the raw counter value of whatever the
     architecture platform provides. The original x86 Time Stamp Counter
     (TSC) was despite its name tied to the actual CPU core frequency.
     That's not longer the case. So the counter value is only meaningful
     when the CPU operates at the same frequency as the TSC or the value is
     adjusted to the actual CPU frequency. Other architectures and
     platforms provide similar disjunct counters via get_cycles(), so the
     result is operations per BOGO-cycles, which is not really meaningful.

Use ktime_get() instead which provides nanosecond timestamps with the
granularity of the underlying hardware counter, which is not different to
the variety of get_cycles() implementations.

This provides at least understandable metrics, i.e. operations/nanoseconds,
and is available on all platforms. As with get_cycles() the result might
have to be put into relation with the CPU operating frequency, but that's
not any different.

This is part of a larger effort to remove get_cycles() usage from
non-architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: linux-crypto@vger.kernel.org
---
 crypto/tcrypt.c |   84 ++++++++++++++++++++++++++++----------------------------
 1 file changed, 42 insertions(+), 42 deletions(-)

--- a/crypto/tcrypt.c
+++ b/crypto/tcrypt.c
@@ -202,7 +202,7 @@ static int test_mb_aead_jiffies(struct t
 static int test_mb_aead_cycles(struct test_mb_aead_data *data, int enc,
 			       int blen, u32 num_mb)
 {
-	unsigned long cycles = 0;
+	unsigned long nsecs = 0;
 	int ret = 0;
 	int i;
 	int *rc;
@@ -220,20 +220,20 @@ static int test_mb_aead_cycles(struct te
 
 	/* The real thing. */
 	for (i = 0; i < 8; i++) {
-		cycles_t start, end;
+		ktime_t start, end;
 
-		start = get_cycles();
+		start = ktime_get();
 		ret = do_mult_aead_op(data, enc, num_mb, rc);
-		end = get_cycles();
+		end = ktime_get();
 
 		if (ret)
 			goto out;
 
-		cycles += end - start;
+		nsecs += (unsigned long)(end - start);
 	}
 
-	pr_cont("1 operation in %lu cycles (%d bytes)\n",
-		(cycles + 4) / (8 * num_mb), blen);
+	pr_cont("1 operation in %lu nsecs (%d bytes)\n",
+		nsecs / (8 * num_mb), blen);
 
 out:
 	kfree(rc);
@@ -475,7 +475,7 @@ static int test_aead_jiffies(struct aead
 
 static int test_aead_cycles(struct aead_request *req, int enc, int blen)
 {
-	unsigned long cycles = 0;
+	unsigned long nsecs = 0;
 	int ret = 0;
 	int i;
 
@@ -492,25 +492,24 @@ static int test_aead_cycles(struct aead_
 
 	/* The real thing. */
 	for (i = 0; i < 8; i++) {
-		cycles_t start, end;
+		ktime_t start, end;
 
-		start = get_cycles();
+		start = ktime_get();
 		if (enc)
 			ret = do_one_aead_op(req, crypto_aead_encrypt(req));
 		else
 			ret = do_one_aead_op(req, crypto_aead_decrypt(req));
-		end = get_cycles();
+		end = ktime_get();
 
 		if (ret)
 			goto out;
 
-		cycles += end - start;
+		nsecs += (unsigned long)(end - start);
 	}
 
 out:
 	if (ret == 0)
-		pr_cont("1 operation in %lu cycles (%d bytes)\n",
-			(cycles + 4) / 8, blen);
+		pr_cont("1 operation in %lu nsecs (%d bytes)\n", nsecs / 8, blen);
 
 	return ret;
 }
@@ -771,7 +770,7 @@ static int test_ahash_jiffies(struct aha
 static int test_ahash_cycles_digest(struct ahash_request *req, int blen,
 				    char *out)
 {
-	unsigned long cycles = 0;
+	unsigned long nsecs = 0;
 	int ret, i;
 
 	/* Warm-up run. */
@@ -783,25 +782,25 @@ static int test_ahash_cycles_digest(stru
 
 	/* The real thing. */
 	for (i = 0; i < 8; i++) {
-		cycles_t start, end;
+		ktime_t start, end;
 
-		start = get_cycles();
+		start = ktime_get();
 
 		ret = do_one_ahash_op(req, crypto_ahash_digest(req));
 		if (ret)
 			goto out;
 
-		end = get_cycles();
+		end = ktime_get();
 
-		cycles += end - start;
+		nsecs += (unsigned long)(end - start);
 	}
 
 out:
 	if (ret)
 		return ret;
 
-	pr_cont("%6lu cycles/operation, %4lu cycles/byte\n",
-		cycles / 8, cycles / (8 * blen));
+	pr_cont("%6lu nsecs/operation, %4lu nsecs/byte\n",
+		nsecs / 8, nsecs / (8 * blen));
 
 	return 0;
 }
@@ -809,7 +808,7 @@ static int test_ahash_cycles_digest(stru
 static int test_ahash_cycles(struct ahash_request *req, int blen,
 			     int plen, char *out)
 {
-	unsigned long cycles = 0;
+	unsigned long nsecs = 0;
 	int i, pcount, ret;
 
 	if (plen == blen)
@@ -832,9 +831,9 @@ static int test_ahash_cycles(struct ahas
 
 	/* The real thing. */
 	for (i = 0; i < 8; i++) {
-		cycles_t start, end;
+		ktime_t start, end;
 
-		start = get_cycles();
+		start = ktime_get();
 
 		ret = do_one_ahash_op(req, crypto_ahash_init(req));
 		if (ret)
@@ -848,17 +847,17 @@ static int test_ahash_cycles(struct ahas
 		if (ret)
 			goto out;
 
-		end = get_cycles();
+		end = ktime_get();
 
-		cycles += end - start;
+		nsecs += (unsigned long)(end - start);
 	}
 
 out:
 	if (ret)
 		return ret;
 
-	pr_cont("%6lu cycles/operation, %4lu cycles/byte\n",
-		cycles / 8, cycles / (8 * blen));
+	pr_cont("%6lu nsecs/operation, %4lu nsecs/byte\n",
+		nsecs / 8, nsecs / (8 * blen));
 
 	return 0;
 }
@@ -1019,7 +1018,7 @@ static int test_mb_acipher_jiffies(struc
 static int test_mb_acipher_cycles(struct test_mb_skcipher_data *data, int enc,
 			       int blen, u32 num_mb)
 {
-	unsigned long cycles = 0;
+	unsigned long nsecs = 0;
 	int ret = 0;
 	int i;
 	int *rc;
@@ -1037,20 +1036,20 @@ static int test_mb_acipher_cycles(struct
 
 	/* The real thing. */
 	for (i = 0; i < 8; i++) {
-		cycles_t start, end;
+		ktime_t start, end;
 
-		start = get_cycles();
+		start = ktime_get();
 		ret = do_mult_acipher_op(data, enc, num_mb, rc);
-		end = get_cycles();
+		end = ktime_get();
 
 		if (ret)
 			goto out;
 
-		cycles += end - start;
+		nsecs += (unsigned long)(end - start);
 	}
 
-	pr_cont("1 operation in %lu cycles (%d bytes)\n",
-		(cycles + 4) / (8 * num_mb), blen);
+	pr_cont("1 operation in %lu nsecs (%d bytes)\n",
+		nsecs / (8 * num_mb), blen);
 
 out:
 	kfree(rc);
@@ -1246,7 +1245,7 @@ static int test_acipher_jiffies(struct s
 static int test_acipher_cycles(struct skcipher_request *req, int enc,
 			       int blen)
 {
-	unsigned long cycles = 0;
+	unsigned long nsecs = 0;
 	int ret = 0;
 	int i;
 
@@ -1265,27 +1264,28 @@ static int test_acipher_cycles(struct sk
 
 	/* The real thing. */
 	for (i = 0; i < 8; i++) {
-		cycles_t start, end;
+		ktime_t start, end;
+
+		start = ktime_get();
 
-		start = get_cycles();
 		if (enc)
 			ret = do_one_acipher_op(req,
 						crypto_skcipher_encrypt(req));
 		else
 			ret = do_one_acipher_op(req,
 						crypto_skcipher_decrypt(req));
-		end = get_cycles();
+		end = ktime_get();
 
 		if (ret)
 			goto out;
 
-		cycles += end - start;
+		nsecs += (unsigned long)(end - start);
 	}
 
 out:
 	if (ret == 0)
-		pr_cont("1 operation in %lu cycles (%d bytes)\n",
-			(cycles + 4) / 8, blen);
+		pr_cont("1 operation in %lu nsecs (%d bytes)\n",
+			nsecs / 8, blen);
 
 	return ret;
 }

[patch 14/38] slub: Use prandom instead of get_cycles()

[Thomas Gleixner]

The decision whether to scan remote nodes is based on a 'random' number
retrieved via get_cycles(). get_cycles() is about to be removed.

There is already prandom state in the code, so use that instead.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: linux-mm@kvack.org
---
 mm/slub.c |   37 +++++++++++++++++++++++--------------
 1 file changed, 23 insertions(+), 14 deletions(-)

--- a/mm/slub.c
+++ b/mm/slub.c
@@ -3302,6 +3302,25 @@ static inline struct slab *alloc_slab_pa
 	return slab;
 }
 
+#if defined(CONFIG_SLAB_FREELIST_RANDOM) || defined(CONFIG_NUMA)
+static DEFINE_PER_CPU(struct rnd_state, slab_rnd_state);
+
+static unsigned int slab_get_prandom_state(unsigned int limit)
+{
+	struct rnd_state *state;
+	unsigned int res;
+
+	/*
+	 * An interrupt or NMI handler might interrupt and change
+	 * the state in the middle, but that's safe.
+	 */
+	state = &get_cpu_var(slab_rnd_state);
+	res = prandom_u32_state(state) % limit;
+	put_cpu_var(slab_rnd_state);
+	return res;
+}
+#endif
+
 #ifdef CONFIG_SLAB_FREELIST_RANDOM
 /* Pre-initialize the random sequence cache */
 static int init_cache_random_seq(struct kmem_cache *s)
@@ -3365,8 +3384,6 @@ static void *next_freelist_entry(struct
 	return (char *)start + idx;
 }
 
-static DEFINE_PER_CPU(struct rnd_state, slab_rnd_state);
-
 /* Shuffle the single linked freelist based on a random pre-computed sequence */
 static bool shuffle_freelist(struct kmem_cache *s, struct slab *slab,
 			     bool allow_spin)
@@ -3383,15 +3400,7 @@ static bool shuffle_freelist(struct kmem
 	if (allow_spin) {
 		pos = get_random_u32_below(freelist_count);
 	} else {
-		struct rnd_state *state;
-
-		/*
-		 * An interrupt or NMI handler might interrupt and change
-		 * the state in the middle, but that's safe.
-		 */
-		state = &get_cpu_var(slab_rnd_state);
-		pos = prandom_u32_state(state) % freelist_count;
-		put_cpu_var(slab_rnd_state);
+		pos = slab_get_prandom_state(freelist_count);
 	}
 
 	page_limit = slab->objects * s->size;
@@ -3882,7 +3891,7 @@ static void *get_from_any_partial(struct
 	 * with available objects.
 	 */
 	if (!s->remote_node_defrag_ratio ||
-			get_cycles() % 1024 > s->remote_node_defrag_ratio)
+	    slab_get_prandom_state(1024) > s->remote_node_defrag_ratio)
 		return NULL;
 
 	do {
@@ -7102,7 +7111,7 @@ static unsigned int
 
 	/* see get_from_any_partial() for the defrag ratio description */
 	if (!s->remote_node_defrag_ratio ||
-			get_cycles() % 1024 > s->remote_node_defrag_ratio)
+	    slab_get_prandom_state(1024) > s->remote_node_defrag_ratio)
 		return 0;
 
 	do {
@@ -8421,7 +8430,7 @@ void __init kmem_cache_init_late(void)
 	flushwq = alloc_workqueue("slub_flushwq", WQ_MEM_RECLAIM | WQ_PERCPU,
 				  0);
 	WARN_ON(!flushwq);
-#ifdef CONFIG_SLAB_FREELIST_RANDOM
+#if defined(CONFIG_SLAB_FREELIST_RANDOM) || defined(CONFIG_NUMA)
 	prandom_init_once(&slab_rnd_state);
 #endif
 }

[patch 15/38] ptp: ptp_vmclock: Replace get_cycles() usage

[Thomas Gleixner]

get_cycles() is not really well defined and similar to other usaage of the
underlying hardware CPU counters the PTP vmclock should use an explicit
interface as well.

Implement ptp_vmclock_read_cpu_counter() in arm64 and x86 and simplify the
Kconfig selection while at it.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: David Woodhouse <dwmw2@infradead.org>
---
 arch/arm64/Kconfig                   |    1 +
 arch/arm64/include/asm/ptp_vmclock.h |   12 ++++++++++++
 arch/x86/Kconfig                     |    1 +
 arch/x86/include/asm/ptp_vmclock.h   |   12 ++++++++++++
 drivers/ptp/Kconfig                  |    6 ++++--
 drivers/ptp/ptp_vmclock.c            |    6 ++++--
 6 files changed, 34 insertions(+), 4 deletions(-)

--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -112,6 +112,7 @@ config ARM64
 	select ARCH_SUPPORTS_SCHED_SMT
 	select ARCH_SUPPORTS_SCHED_CLUSTER
 	select ARCH_SUPPORTS_SCHED_MC
+	select ARCH_SUPPORTS_PTP_VMCLOCK if ARCH_SUPPORTS_INT128
 	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
 	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT
 	select ARCH_WANT_DEFAULT_BPF_JIT
--- /dev/null
+++ b/arch/arm64/include/asm/ptp_vmclock.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_PTP_VMCLOCK_H
+#define __ASM_PTP_VMCLOCK_H
+
+#include <asm/arch_timer.h>
+
+static inline u64 ptp_vmclock_read_cpu_counter(void)
+{
+	return arch_timer_read_counter();
+}
+
+#endif
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -135,6 +135,7 @@ config X86
 	select ARCH_SUPPORTS_RT
 	select ARCH_SUPPORTS_AUTOFDO_CLANG
 	select ARCH_SUPPORTS_PROPELLER_CLANG    if X86_64
+	select ARCH_SUPPORTS_PTP_VMCLOCK	if X86_TSC
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF		if X86_CX8
 	select ARCH_USE_MEMTEST
--- /dev/null
+++ b/arch/x86/include/asm/ptp_vmclock.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_PTP_VMCLOCK_H
+#define __ASM_PTP_VMCLOCK_H
+
+#include <asm/tsc.h>
+
+static inline u64 ptp_vmclock_read_cpu_counter(void)
+{
+	return cpu_feature_enabled(X86_FEATURE_TSC) ? rdtsc() : 0;
+}
+
+#endif
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -131,10 +131,12 @@ config PTP_1588_CLOCK_KVM
 	  To compile this driver as a module, choose M here: the module
 	  will be called ptp_kvm.
 
+config ARCH_SUPPORTS_PTP_VMCLOCK
+	bool
+
 config PTP_1588_CLOCK_VMCLOCK
 	tristate "Virtual machine PTP clock"
-	depends on X86_TSC || ARM_ARCH_TIMER
-	depends on PTP_1588_CLOCK && ARCH_SUPPORTS_INT128
+	depends on PTP_1588_CLOCK && ARCH_SUPPORTS_PTP_VMCLOCK
 	default PTP_1588_CLOCK_KVM
 	help
 	  This driver adds support for using a virtual precision clock
--- a/drivers/ptp/ptp_vmclock.c
+++ b/drivers/ptp/ptp_vmclock.c
@@ -28,6 +28,8 @@
 
 #include <linux/ptp_clock_kernel.h>
 
+#include <asm/ptp_vmclock.h>
+
 #ifdef CONFIG_X86
 #include <asm/pvclock.h>
 #include <asm/kvmclock.h>
@@ -144,11 +146,11 @@ static int vmclock_get_crosststamp(struc
 			if (systime_snapshot.cs_id == st->cs_id) {
 				cycle = systime_snapshot.cycles;
 			} else {
-				cycle = get_cycles();
+				cycle = ptp_vmclock_read_cpu_counter();
 				ptp_read_system_postts(sts);
 			}
 		} else {
-			cycle = get_cycles();
+			cycle = ptp_vmclock_read_cpu_counter();
 		}
 
 		delta = cycle - le64_to_cpu(st->clk->counter_value);

[patch 16/38] fbdev: udlfb: Replace get_cycles() with ktime_get()

[Thomas Gleixner]

These metrics are not really requiring CPU cycles and as those are
meanlingless when the CPU is running at a different frequency, this can use
ktime_get() and achieve the same result.

Part of a larger effort to confine get_cycles() access to low level
architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Bernie Thompson <bernie@plugable.com>
Cc: linux-fbdev@vger.kernel.org
---
 Documentation/fb/udlfb.rst  |    4 ++--
 drivers/video/fbdev/udlfb.c |   24 ++++++++++++------------
 2 files changed, 14 insertions(+), 14 deletions(-)

--- a/Documentation/fb/udlfb.rst
+++ b/Documentation/fb/udlfb.rst
@@ -156,8 +156,8 @@ metrics_bytes_sent	 32-bit count of how
 			 USB to communicate the resulting changed pixels to the
 			 hardware. Includes compression and protocol overhead
 
-metrics_cpu_kcycles_used 32-bit count of CPU cycles used in processing the
-			 above pixels (in thousands of cycles).
+metrics_cpu_kcycles_used 32-bit count of microseconds used in processing the
+			 above pixels
 
 metrics_reset		 Write-only. Any write to this file resets all metrics
 			 above to zero.  Note that the 32-bit counters above
--- a/drivers/video/fbdev/udlfb.c
+++ b/drivers/video/fbdev/udlfb.c
@@ -24,6 +24,7 @@
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/unaligned.h>
+#include <linux/timekeeping.h>
 #include <video/udlfb.h>
 #include "edid.h"
 
@@ -600,15 +601,15 @@ static int dlfb_render_hline(struct dlfb
 
 static int dlfb_handle_damage(struct dlfb_data *dlfb, int x, int y, int width, int height)
 {
+	ktime_t t_start, t_delta;
 	int i, ret;
 	char *cmd;
-	cycles_t start_cycles, end_cycles;
 	int bytes_sent = 0;
 	int bytes_identical = 0;
 	struct urb *urb;
 	int aligned_x;
 
-	start_cycles = get_cycles();
+	t_start = ktime_get();
 
 	mutex_lock(&dlfb->render_mutex);
 
@@ -661,10 +662,9 @@ static int dlfb_handle_damage(struct dlf
 	atomic_add(bytes_sent, &dlfb->bytes_sent);
 	atomic_add(bytes_identical, &dlfb->bytes_identical);
 	atomic_add(width*height*2, &dlfb->bytes_rendered);
-	end_cycles = get_cycles();
-	atomic_add(((unsigned int) ((end_cycles - start_cycles)
-		    >> 10)), /* Kcycles */
-		   &dlfb->cpu_kcycles_used);
+	t_delta = ktime_get() - t_start;
+	/* Avoid a division and approximate microseconds with shift right ten */
+	atomic_add(((int)(t_delta >> 10)), &dlfb->cpu_kcycles_used);
 
 	ret = 0;
 
@@ -727,9 +727,9 @@ static void dlfb_dpy_deferred_io(struct
 {
 	struct fb_deferred_io_pageref *pageref;
 	struct dlfb_data *dlfb = info->par;
+	ktime_t t_start, t_delta;
 	struct urb *urb;
 	char *cmd;
-	cycles_t start_cycles, end_cycles;
 	int bytes_sent = 0;
 	int bytes_identical = 0;
 	int bytes_rendered = 0;
@@ -742,7 +742,7 @@ static void dlfb_dpy_deferred_io(struct
 	if (!atomic_read(&dlfb->usb_active))
 		goto unlock_ret;
 
-	start_cycles = get_cycles();
+	t_start = ktime_get();
 
 	urb = dlfb_get_urb(dlfb);
 	if (!urb)
@@ -774,10 +774,10 @@ static void dlfb_dpy_deferred_io(struct
 	atomic_add(bytes_sent, &dlfb->bytes_sent);
 	atomic_add(bytes_identical, &dlfb->bytes_identical);
 	atomic_add(bytes_rendered, &dlfb->bytes_rendered);
-	end_cycles = get_cycles();
-	atomic_add(((unsigned int) ((end_cycles - start_cycles)
-		    >> 10)), /* Kcycles */
-		   &dlfb->cpu_kcycles_used);
+	t_delta = ktime_get() - t_start;
+	/* Avoid a division and approximate microseconds with shift right ten */
+	atomic_add(((int)(t_delta >> 10)), &dlfb->cpu_kcycles_used);
+
 unlock_ret:
 	mutex_unlock(&dlfb->render_mutex);
 }

[patch 17/38] ext4: Replace get_cycles() usage with ktime_get()

[Thomas Gleixner]

get_cycles() is not guaranteed to be functional on all systems/platforms
and the values returned are unitless and not easy to map to something
useful.

Use ktime_get() instead, which provides nanosecond timestamps and is
functional everywhere.

This is part of a larger effort to limit get_cycles() usage to low level
architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/mballoc.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1289,7 +1289,7 @@ void ext4_mb_generate_buddy(struct super
 	ext4_grpblk_t len;
 	unsigned free = 0;
 	unsigned fragments = 0;
-	unsigned long long period = get_cycles();
+	ktime_t period = ktime_get();
 
 	/* initialize buddy from bitmap which is aggregation
 	 * of on-disk bitmap and preallocations */
@@ -1328,7 +1328,7 @@ void ext4_mb_generate_buddy(struct super
 
 	clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
 
-	period = get_cycles() - period;
+	period = ktime_get() - period;
 	atomic_inc(&sbi->s_mb_buddies_generated);
 	atomic64_add(period, &sbi->s_mb_generation_time);
 }

[patch 18/38] lib/tests: Replace get_cycles() with ktime_get()

[Thomas Gleixner]

get_cycles() is the historical access to a fine grained time source, but it
is a suboptimal choice for two reasons:

   - get_cycles() is not guaranteed to be supported and functional on all
     systems/platforms. If not supported or not functional it returns 0,
     which makes benchmarking moot.

   - get_cycles() returns the raw counter value of whatever the
     architecture platform provides. The original x86 Time Stamp Counter
     (TSC) was despite its name tied to the actual CPU core frequency.
     That's not longer the case. So the counter value is only meaningful
     when the CPU operates at the same frequency as the TSC or the value is
     adjusted to the actual CPU frequency. Other architectures and
     platforms provide similar disjunct counters via get_cycles(), so the
     result is operations per BOGO-cycles, which is not really meaningful.

Use ktime_get() instead which provides nanosecond timestamps with the
granularity of the underlying hardware counter, which is not different to
the variety of get_cycles() implementations.

This provides at least understandable metrics, i.e. operations/nanoseconds,
and is available on all platforms. As with get_cycles() the result might
have to be put into relation with the CPU operating frequency, but that's
not any different.

This is part of a larger effort to remove get_cycles() usage from
non-architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: linux-mm@kvack.org
---
 lib/interval_tree_test.c |   16 ++++++++--------
 lib/rbtree_test.c        |   46 +++++++++++++++++++++++-----------------------
 lib/test_vmalloc.c       |   10 +++++-----
 3 files changed, 36 insertions(+), 36 deletions(-)

--- a/lib/interval_tree_test.c
+++ b/lib/interval_tree_test.c
@@ -65,13 +65,13 @@ static void init(void)
 static int basic_check(void)
 {
 	int i, j;
-	cycles_t time1, time2, time;
+	ktime_t time1, time2, time;
 
 	printk(KERN_ALERT "interval tree insert/remove");
 
 	init();
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++) {
 		for (j = 0; j < nnodes; j++)
@@ -80,11 +80,11 @@ static int basic_check(void)
 			interval_tree_remove(nodes + j, &root);
 	}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk(" -> %llu cycles\n", (unsigned long long)time);
+	printk(" -> %llu nsecs\n", (unsigned long long)time);
 
 	return 0;
 }
@@ -93,7 +93,7 @@ static int search_check(void)
 {
 	int i, j;
 	unsigned long results;
-	cycles_t time1, time2, time;
+	ktime_t time1, time2, time;
 
 	printk(KERN_ALERT "interval tree search");
 
@@ -102,7 +102,7 @@ static int search_check(void)
 	for (j = 0; j < nnodes; j++)
 		interval_tree_insert(nodes + j, &root);
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	results = 0;
 	for (i = 0; i < search_loops; i++)
@@ -113,12 +113,12 @@ static int search_check(void)
 			results += search(&root, start, last);
 		}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, search_loops);
 	results = div_u64(results, search_loops);
-	printk(" -> %llu cycles (%lu results)\n",
+	printk(" -> %llu nsecs (%lu results)\n",
 	       (unsigned long long)time, results);
 
 	for (j = 0; j < nnodes; j++)
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -243,14 +243,14 @@ static void check_augmented(int nr_nodes
 static int basic_check(void)
 {
 	int i, j;
-	cycles_t time1, time2, time;
+	ktime_t time1, time2, time;
 	struct rb_node *node;
 
 	printk(KERN_ALERT "rbtree testing");
 
 	init();
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++) {
 		for (j = 0; j < nnodes; j++)
@@ -259,14 +259,14 @@ static int basic_check(void)
 			erase(nodes + j, &root);
 	}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n",
+	printk(" -> test 1 (latency of nnodes insert+delete): %llu nsecs\n",
 	       (unsigned long long)time);
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++) {
 		for (j = 0; j < nnodes; j++)
@@ -275,52 +275,52 @@ static int basic_check(void)
 			erase_cached(nodes + j, &root);
 	}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n",
+	printk(" -> test 2 (latency of nnodes cached insert+delete): %llu nsecs\n",
 	       (unsigned long long)time);
 
 	for (i = 0; i < nnodes; i++)
 		insert(nodes + i, &root);
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++) {
 		for (node = rb_first(&root.rb_root); node; node = rb_next(node))
 			;
 	}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk(" -> test 3 (latency of inorder traversal): %llu cycles\n",
+	printk(" -> test 3 (latency of inorder traversal): %llu nsecs\n",
 	       (unsigned long long)time);
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++)
 		node = rb_first(&root.rb_root);
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
 	printk(" -> test 4 (latency to fetch first node)\n");
-	printk("        non-cached: %llu cycles\n", (unsigned long long)time);
+	printk("        non-cached: %llu nsecs\n", (unsigned long long)time);
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++)
 		node = rb_first_cached(&root);
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk("        cached: %llu cycles\n", (unsigned long long)time);
+	printk("        cached: %llu nsecs\n", (unsigned long long)time);
 
 	for (i = 0; i < nnodes; i++)
 		erase(nodes + i, &root);
@@ -345,13 +345,13 @@ static int basic_check(void)
 static int augmented_check(void)
 {
 	int i, j;
-	cycles_t time1, time2, time;
+	ktime_t time1, time2, time;
 
 	printk(KERN_ALERT "augmented rbtree testing");
 
 	init();
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++) {
 		for (j = 0; j < nnodes; j++)
@@ -360,13 +360,13 @@ static int augmented_check(void)
 			erase_augmented(nodes + j, &root);
 	}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk(" -> test 1 (latency of nnodes insert+delete): %llu cycles\n", (unsigned long long)time);
+	printk(" -> test 1 (latency of nnodes insert+delete): %llu nsecs\n", (unsigned long long)time);
 
-	time1 = get_cycles();
+	time1 = ktime_get();
 
 	for (i = 0; i < perf_loops; i++) {
 		for (j = 0; j < nnodes; j++)
@@ -375,11 +375,11 @@ static int augmented_check(void)
 			erase_augmented_cached(nodes + j, &root);
 	}
 
-	time2 = get_cycles();
+	time2 = ktime_get();
 	time = time2 - time1;
 
 	time = div_u64(time, perf_loops);
-	printk(" -> test 2 (latency of nnodes cached insert+delete): %llu cycles\n", (unsigned long long)time);
+	printk(" -> test 2 (latency of nnodes cached insert+delete): %llu nsecs\n", (unsigned long long)time);
 
 	for (i = 0; i < check_loops; i++) {
 		init();
--- a/lib/test_vmalloc.c
+++ b/lib/test_vmalloc.c
@@ -454,8 +454,8 @@ static struct test_driver {
 	struct task_struct *task;
 	struct test_case_data data[ARRAY_SIZE(test_case_array)];
 
-	unsigned long start;
-	unsigned long stop;
+	ktime_t start;
+	ktime_t stop;
 } *tdriver;
 
 static void shuffle_array(int *arr, int n)
@@ -490,7 +490,7 @@ static int test_func(void *private)
 	 */
 	synchronize_srcu(&prepare_for_test_srcu);
 
-	t->start = get_cycles();
+	t->start = ktime_get();
 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
 		index = random_array[i];
 
@@ -519,7 +519,7 @@ static int test_func(void *private)
 
 		t->data[index].time = delta;
 	}
-	t->stop = get_cycles();
+	t->stop = ktime_get();
 	test_report_one_done();
 
 	/*
@@ -619,7 +619,7 @@ static void do_concurrent_test(void)
 				t->data[j].time);
 		}
 
-		pr_info("All test took worker%d=%lu cycles\n",
+		pr_info("All test took worker%d=%lld nsecs\n",
 			i, t->stop - t->start);
 	}
 

[patch 19/38] kcsan: Replace get_cycles() usage

[Thomas Gleixner]

KCSAN uses get_cycles() for two purposes:

  1) Seeding the random state with get_cycles() is a historical leftover.

  2) The microbenchmark uses get_cycles(), which provides an unit less
     counter value and is not guaranteed to be functional on all
     systems/platforms.

Use random_get_entropy() for seeding the random state and ktime_get() which
is universaly functional and provides at least a comprehensible unit.

This is part of a larger effort to remove get_cycles() usage from
non-architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: kasan-dev@googlegroups.com
---
 kernel/kcsan/core.c    |    2 +-
 kernel/kcsan/debugfs.c |    8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

--- a/kernel/kcsan/core.c
+++ b/kernel/kcsan/core.c
@@ -798,7 +798,7 @@ void __init kcsan_init(void)
 	BUG_ON(!in_task());
 
 	for_each_possible_cpu(cpu)
-		per_cpu(kcsan_rand_state, cpu) = (u32)get_cycles();
+		per_cpu(kcsan_rand_state, cpu) = (u32)random_get_entropy();
 
 	/*
 	 * We are in the init task, and no other tasks should be running;
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -58,7 +58,7 @@ static noinline void microbenchmark(unsi
 {
 	const struct kcsan_ctx ctx_save = current->kcsan_ctx;
 	const bool was_enabled = READ_ONCE(kcsan_enabled);
-	u64 cycles;
+	ktime_t nsecs;
 
 	/* We may have been called from an atomic region; reset context. */
 	memset(&current->kcsan_ctx, 0, sizeof(current->kcsan_ctx));
@@ -70,16 +70,16 @@ static noinline void microbenchmark(unsi
 
 	pr_info("%s begin | iters: %lu\n", __func__, iters);
 
-	cycles = get_cycles();
+	nsecs = ktime_get();
 	while (iters--) {
 		unsigned long addr = iters & ((PAGE_SIZE << 8) - 1);
 		int type = !(iters & 0x7f) ? KCSAN_ACCESS_ATOMIC :
 				(!(iters & 0xf) ? KCSAN_ACCESS_WRITE : 0);
 		__kcsan_check_access((void *)addr, sizeof(long), type);
 	}
-	cycles = get_cycles() - cycles;
+	nsecs = ktime_get() - nsecs;
 
-	pr_info("%s end   | cycles: %llu\n", __func__, cycles);
+	pr_info("%s end   | nsecs: %llu\n", __func__, nsecs);
 
 	WRITE_ONCE(kcsan_enabled, was_enabled);
 	/* restore context */

Re: [patch 19/38] kcsan: Replace get_cycles() usage

[Marco Elver]

On Fri, 10 Apr 2026 at 14:20, Thomas Gleixner <tglx@kernel.org> wrote:
>
> KCSAN uses get_cycles() for two purposes:
>
>   1) Seeding the random state with get_cycles() is a historical leftover.
>
>   2) The microbenchmark uses get_cycles(), which provides an unit less
>      counter value and is not guaranteed to be functional on all
>      systems/platforms.
>
> Use random_get_entropy() for seeding the random state and ktime_get() which
> is universaly functional and provides at least a comprehensible unit.
>
> This is part of a larger effort to remove get_cycles() usage from
> non-architecture code.
>
> Signed-off-by: Thomas Gleixner <tglx@kernel.org>
> Cc: Marco Elver <elver@google.com>
> Cc: Dmitry Vyukov <dvyukov@google.com>
> Cc: kasan-dev@googlegroups.com

Reviewed-by: Marco Elver <elver@google.com>

> ---
>  kernel/kcsan/core.c    |    2 +-
>  kernel/kcsan/debugfs.c |    8 ++++----
>  2 files changed, 5 insertions(+), 5 deletions(-)
>
> --- a/kernel/kcsan/core.c
> +++ b/kernel/kcsan/core.c
> @@ -798,7 +798,7 @@ void __init kcsan_init(void)
>         BUG_ON(!in_task());
>
>         for_each_possible_cpu(cpu)
> -               per_cpu(kcsan_rand_state, cpu) = (u32)get_cycles();
> +               per_cpu(kcsan_rand_state, cpu) = (u32)random_get_entropy();
>
>         /*
>          * We are in the init task, and no other tasks should be running;
> --- a/kernel/kcsan/debugfs.c
> +++ b/kernel/kcsan/debugfs.c
> @@ -58,7 +58,7 @@ static noinline void microbenchmark(unsi
>  {
>         const struct kcsan_ctx ctx_save = current->kcsan_ctx;
>         const bool was_enabled = READ_ONCE(kcsan_enabled);
> -       u64 cycles;
> +       ktime_t nsecs;
>
>         /* We may have been called from an atomic region; reset context. */
>         memset(&current->kcsan_ctx, 0, sizeof(current->kcsan_ctx));
> @@ -70,16 +70,16 @@ static noinline void microbenchmark(unsi
>
>         pr_info("%s begin | iters: %lu\n", __func__, iters);
>
> -       cycles = get_cycles();
> +       nsecs = ktime_get();
>         while (iters--) {
>                 unsigned long addr = iters & ((PAGE_SIZE << 8) - 1);
>                 int type = !(iters & 0x7f) ? KCSAN_ACCESS_ATOMIC :
>                                 (!(iters & 0xf) ? KCSAN_ACCESS_WRITE : 0);
>                 __kcsan_check_access((void *)addr, sizeof(long), type);
>         }
> -       cycles = get_cycles() - cycles;
> +       nsecs = ktime_get() - nsecs;
>
> -       pr_info("%s end   | cycles: %llu\n", __func__, cycles);
> +       pr_info("%s end   | nsecs: %llu\n", __func__, nsecs);
>
>         WRITE_ONCE(kcsan_enabled, was_enabled);
>         /* restore context */
>

[patch 20/38] kasan: sw_tags: Replace get_cycles() by random_get_entropy()

[Thomas Gleixner]

Seeding the random state with get_cycles() is functionally equivalent on
the architectures which provide get_cycles(), but it does not make sense
semantically.

Use random_get_entropy() instead, which is the proper interface.

This is part of a larger effort to remove get_cycles() usage from
non-architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: kasan-dev@googlegroups.com
---
 mm/kasan/sw_tags.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -41,7 +41,7 @@ void __init kasan_init_sw_tags(void)
 	int cpu;
 
 	for_each_possible_cpu(cpu)
-		per_cpu(prng_state, cpu) = (u32)get_cycles();
+		per_cpu(prng_state, cpu) = (u32)random_get_entropy();
 
 	kasan_init_tags();
 	kasan_enable();

[patch 21/38] hamradio: baycom_epp: Remove BAYCOM_DEBUG

[Thomas Gleixner]

The whole code guarded by BAYCOM_DEBUG is only writing debug values into a
datastructure, but there is no way to ever access them.

Remove the pointless ballast.

This is part of a larger effort to remove get_cycles() usage from
non-architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Thomas Sailer <t.sailer@alumni.ethz.ch>
Cc: linux-hams@vger.kernel.org
---
 drivers/net/hamradio/baycom_epp.c |   51 --------------------------------------
 1 file changed, 51 deletions(-)

--- a/drivers/net/hamradio/baycom_epp.c
+++ b/drivers/net/hamradio/baycom_epp.c
@@ -44,7 +44,6 @@
 
 /* --------------------------------------------------------------------- */
 
-#define BAYCOM_DEBUG
 #define BAYCOM_MAGIC 19730510
 
 /* --------------------------------------------------------------------- */
@@ -191,18 +190,6 @@ struct baycom_state {
 
 	unsigned int ptt_keyed;
 	struct sk_buff *skb;  /* next transmit packet  */
-
-#ifdef BAYCOM_DEBUG
-	struct debug_vals {
-		unsigned long last_jiffies;
-		unsigned cur_intcnt;
-		unsigned last_intcnt;
-		int cur_pllcorr;
-		int last_pllcorr;
-		unsigned int mod_cycles;
-		unsigned int demod_cycles;
-	} debug_vals;
-#endif /* BAYCOM_DEBUG */
 };
 
 /* --------------------------------------------------------------------- */
@@ -259,26 +246,6 @@ static inline int calc_crc_ccitt(const u
 
 #define tenms_to_flags(bc,tenms) ((tenms * bc->bitrate) / 800)
 
-/* --------------------------------------------------------------------- */
-
-static inline void baycom_int_freq(struct baycom_state *bc)
-{
-#ifdef BAYCOM_DEBUG
-	unsigned long cur_jiffies = jiffies;
-	/*
-	 * measure the interrupt frequency
-	 */
-	bc->debug_vals.cur_intcnt++;
-	if (time_after_eq(cur_jiffies, bc->debug_vals.last_jiffies + HZ)) {
-		bc->debug_vals.last_jiffies = cur_jiffies;
-		bc->debug_vals.last_intcnt = bc->debug_vals.cur_intcnt;
-		bc->debug_vals.cur_intcnt = 0;
-		bc->debug_vals.last_pllcorr = bc->debug_vals.cur_pllcorr;
-		bc->debug_vals.cur_pllcorr = 0;
-	}
-#endif /* BAYCOM_DEBUG */
-}
-
 /* ---------------------------------------------------------------------- */
 /*
  *    eppconfig_path should be setable  via /proc/sys.
@@ -621,13 +588,6 @@ static int receive(struct net_device *de
 	return ret;
 }
 
-/* --------------------------------------------------------------------- */
-
-#define GETTICK(x)						\
-({								\
-	x = (unsigned int)get_cycles();				\
-})
-
 static void epp_bh(struct work_struct *work)
 {
 	struct net_device *dev;
@@ -635,21 +595,17 @@ static void epp_bh(struct work_struct *w
 	struct parport *pp;
 	unsigned char stat;
 	unsigned char tmp[2];
-	unsigned int time1 = 0, time2 = 0, time3 = 0;
 	int cnt, cnt2;
 
 	bc = container_of(work, struct baycom_state, run_work.work);
 	dev = bc->dev;
 	if (!bc->work_running)
 		return;
-	baycom_int_freq(bc);
 	pp = bc->pdev->port;
 	/* update status */
 	if (pp->ops->epp_read_addr(pp, &stat, 1, 0) != 1)
 		goto epptimeout;
 	bc->stat = stat;
-	bc->debug_vals.last_pllcorr = stat;
-	GETTICK(time1);
 	if (bc->modem == EPP_FPGAEXTSTATUS) {
 		/* get input count */
 		tmp[0] = EPP_TX_FIFO_ENABLE|EPP_RX_FIFO_ENABLE|EPP_MODEM_ENABLE|1;
@@ -673,7 +629,6 @@ static void epp_bh(struct work_struct *w
 			goto epptimeout;
 		if (transmit(bc, cnt2, stat))
 			goto epptimeout;
-		GETTICK(time2);
 		if (receive(dev, cnt))
 			goto epptimeout;
 		if (pp->ops->epp_read_addr(pp, &stat, 1, 0) != 1)
@@ -700,7 +655,6 @@ static void epp_bh(struct work_struct *w
 		}
 		if (transmit(bc, cnt, stat))
 			goto epptimeout;
-		GETTICK(time2);
 		/* do receiver */
 		while ((stat & (EPP_NRAEF|EPP_NRHF)) != EPP_NRHF) {
 			switch (stat & (EPP_NRAEF|EPP_NRHF)) {
@@ -734,11 +688,6 @@ static void epp_bh(struct work_struct *w
 				goto epptimeout;
 		}
 	}
-	GETTICK(time3);
-#ifdef BAYCOM_DEBUG
-	bc->debug_vals.mod_cycles = time2 - time1;
-	bc->debug_vals.demod_cycles = time3 - time2;
-#endif /* BAYCOM_DEBUG */
 	schedule_delayed_work(&bc->run_work, 1);
 	if (!bc->skb)
 		netif_wake_queue(dev);

[patch 22/38] random: Provide CONFIG_ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

Chasing down to what random_get_entropy() resolves is a 'spot the mouse'
game through a maze of #ifdeffery. Also the placement in timex.h is
non-obvious and has just been chosen because it provides conveniant access
to the underlying get_cycles() #ifdeffery.

Provide a config switch which is selectable by the architecture and a
temporary #ifdef guard in timex.h. Architectures which select the config
switch must provide asm/random.h with the architecture specific
implementation.

Update all usage sites to include linux/random.h so that the gradual
conversion does not cause build regressions.

This is part of a larger effort to remove get_cycles() usage from
non-architecture code.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
---
 arch/Kconfig                     |    3 +++
 arch/loongarch/kernel/relocate.c |    1 +
 arch/mips/kernel/relocate.c      |    1 +
 crypto/jitterentropy-kcapi.c     |    1 +
 include/linux/random.h           |   15 +++++++++++++++
 include/linux/timex.h            |    2 ++
 kernel/kcsan/core.c              |    1 +
 7 files changed, 24 insertions(+)

--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -370,6 +370,9 @@ config ARCH_HAS_CPU_FINALIZE_INIT
 config ARCH_HAS_DELAY_TIMER
 	bool
 
+config ARCH_HAS_RANDOM_ENTROPY
+	bool
+
 # The architecture has a per-task state that includes the mm's PASID
 config ARCH_HAS_CPU_PASID
 	bool
--- a/arch/loongarch/kernel/relocate.c
+++ b/arch/loongarch/kernel/relocate.c
@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/printk.h>
 #include <linux/panic_notifier.h>
+#include <linux/random.h>
 #include <linux/start_kernel.h>
 #include <asm/bootinfo.h>
 #include <asm/early_ioremap.h>
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c
@@ -19,6 +19,7 @@
 #include <linux/libfdt.h>
 #include <linux/of_fdt.h>
 #include <linux/panic_notifier.h>
+#include <linux/random.h>
 #include <linux/sched/task.h>
 #include <linux/start_kernel.h>
 #include <linux/string.h>
--- a/crypto/jitterentropy-kcapi.c
+++ b/crypto/jitterentropy-kcapi.c
@@ -42,6 +42,7 @@
 #include <linux/fips.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/random.h>
 #include <linux/slab.h>
 #include <linux/time.h>
 #include <crypto/internal/rng.h>
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -139,4 +139,19 @@ int random_online_cpu(unsigned int cpu);
 extern const struct file_operations random_fops, urandom_fops;
 #endif
 
+unsigned long random_get_entropy_fallback(void);
+
+/*
+ * random_get_entropy() is used by the /dev/random driver in order to extract
+ * entropy via the relative unpredictability of when an interrupt takes places
+ * versus a high speed, fine-grained timing source or cycle counter.  Since it
+ * will be occurred on every single interrupt, it must have a very low
+ * cost/overhead.
+ *
+ * If an architecture does not provide it, then use random_get_entropy_fallback().
+ */
+#ifdef CONFIG_ARCH_HAS_RANDOM_ENTROPY
+#include <asm/random.h>
+#endif
+
 #endif /* _LINUX_RANDOM_H */
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -66,6 +66,7 @@ unsigned long random_get_entropy_fallbac
 
 #include <asm/timex.h>
 
+#ifndef CONFIG_ARCH_HAS_RANDOM_ENTROPY
 #ifndef random_get_entropy
 /*
  * The random_get_entropy() function is used by the /dev/random driver
@@ -85,6 +86,7 @@ unsigned long random_get_entropy_fallbac
 #define random_get_entropy()	random_get_entropy_fallback()
 #endif
 #endif
+#endif
 
 /*
  * SHIFT_PLL is used as a dampening factor to define how much we
--- a/kernel/kcsan/core.c
+++ b/kernel/kcsan/core.c
@@ -18,6 +18,7 @@
 #include <linux/moduleparam.h>
 #include <linux/percpu.h>
 #include <linux/preempt.h>
+#include <linux/random.h>
 #include <linux/sched.h>
 #include <linux/string.h>
 #include <linux/uaccess.h>

[patch 23/38] alpha: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide
random_get_entropy().

Switch alpha over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: linux-alpha@vger.kernel.org
---
 arch/alpha/Kconfig              |    1 +
 arch/alpha/include/asm/random.h |   14 ++++++++++++++
 arch/alpha/include/asm/timex.h  |   26 --------------------------
 3 files changed, 15 insertions(+), 26 deletions(-)

--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -5,6 +5,7 @@ config ALPHA
 	select ARCH_32BIT_USTAT_F_TINODE
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DMA_OPS if PCI
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
 	select ARCH_MODULE_NEEDS_WEAK_PER_CPU if SMP
--- /dev/null
+++ b/arch/alpha/include/asm/random.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASMALPHA_RANDOM_H
+#define _ASMALPHA_RANDOM_H
+
+/* Use the cycle counter for entropy. */
+static inline unsigned long random_get_entropy(void)
+{
+	unsigned long ret;
+
+	__asm__ __volatile__ ("rpcc %0" : "=r"(ret));
+	return ret;
+}
+
+#endif
--- a/arch/alpha/include/asm/timex.h
+++ /dev/null
@@ -1,26 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * linux/include/asm-alpha/timex.h
- *
- * ALPHA architecture timex specifications
- */
-#ifndef _ASMALPHA_TIMEX_H
-#define _ASMALPHA_TIMEX_H
-
-/*
- * Standard way to access the cycle counter.
- * Currently only used on SMP for scheduling.
- *
- * Only the low 32 bits are available as a continuously counting entity. 
- * But this only means we'll force a reschedule every 8 seconds or so,
- * which isn't an evil thing.
- */
-static inline cycles_t get_cycles (void)
-{
-	cycles_t ret;
-	__asm__ __volatile__ ("rpcc %0" : "=r"(ret));
-	return ret;
-}
-#define get_cycles get_cycles
-
-#endif

[patch 24/38] ARM: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide
random_get_entropy().

Switch ARM over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
providing random_get_entropy() in asm/random.h.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm/Kconfig              |    1 +
 arch/arm/include/asm/random.h |   14 ++++++++++++++
 arch/arm/include/asm/timex.h  |   18 ------------------
 arch/arm/lib/delay.c          |    4 ++--
 4 files changed, 17 insertions(+), 20 deletions(-)

--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -22,6 +22,7 @@ config ARM
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_STACKWALK
--- /dev/null
+++ b/arch/arm/include/asm/random.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASMARM_RANDOM_H
+#define _ASMARM_RANDOM_H
+
+bool delay_read_timer(unsigned long *t);
+
+static inline unsigned long random_get_entropy(void)
+{
+	unsigned long t;
+
+	return delay_read_timer(&t) ? t : random_get_entropy_fallback();
+}
+
+#endif
--- a/arch/arm/include/asm/timex.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- *  arch/arm/include/asm/timex.h
- *
- *  Copyright (C) 1997,1998 Russell King
- *
- *  Architecture Specific TIME specifications
- */
-#ifndef _ASMARM_TIMEX_H
-#define _ASMARM_TIMEX_H
-
-// Temporary workaround
-bool delay_read_timer(unsigned long *t);
-
-#define get_cycles()	({ cycles_t c; delay_read_timer(&c) ? 0 : c; })
-#define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback())
-
-#endif
--- a/arch/arm/lib/delay.c
+++ b/arch/arm/lib/delay.c
@@ -42,9 +42,9 @@ static inline u64 cyc_to_ns(u64 cyc, u32
 
 static void __timer_delay(unsigned long cycles)
 {
-	cycles_t start = get_cycles();
+	cycles_t start = delay_timer->read_current_timer();
 
-	while ((get_cycles() - start) < cycles)
+	while ((delay_timer->read_current_timer() - start) < cycles)
 		cpu_relax();
 }
 

[patch 25/38] arm64: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide random_get_entropy().

Switch arm64 over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

As a consequence this unearthed a nasty include dependecy hell where random
code including rqspinlock.h relies on a magic include of asm/arch_timer.h.
Including the headers in asm/random.h turned out to be impossible as well.

The only solution for now is to uninline random_get_entropy().  Fix up all
other dependencies on the content of asm/timex.h in those files which
really depend on it.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
---
 arch/arm64/Kconfig                      |    1 +
 arch/arm64/include/asm/io.h             |    5 +++--
 arch/arm64/include/asm/random.h         |   11 +++++++++++
 arch/arm64/include/asm/rqspinlock.h     |    1 +
 arch/arm64/include/asm/timex.h          |   18 ------------------
 arch/arm64/kernel/time.c                |    6 ++++++
 arch/arm64/kernel/topology.c            |    1 +
 arch/arm64/kernel/traps.c               |    1 +
 arch/arm64/kvm/emulate-nested.c         |    1 +
 arch/arm64/kvm/hyp/include/hyp/switch.h |    1 +
 arch/arm64/lib/delay.c                  |    1 +
 drivers/irqchip/irq-apple-aic.c         |    1 +
 12 files changed, 28 insertions(+), 20 deletions(-)

--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -45,6 +45,7 @@ config ARM64
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_HW_PTE_YOUNG
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_DIRECT_MAP
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -100,12 +100,13 @@ static __always_inline u64 __raw_readq(c
 ({									\
 	unsigned long tmp;						\
 									\
-	dma_rmb();								\
+	dma_rmb();							\
 									\
 	/*								\
 	 * Create a dummy control dependency from the IO read to any	\
 	 * later instructions. This ensures that a subsequent call to	\
-	 * udelay() will be ordered due to the ISB in get_cycles().	\
+	 * udelay() will be ordered due to the ISB in			\
+	 * arm_timer_read_counter().					\
 	 */								\
 	asm volatile("eor	%0, %1, %1\n"				\
 		     "cbnz	%0, ."					\
--- /dev/null
+++ b/arch/arm64/include/asm/random.h
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ */
+#ifndef __ASM_RANDOM_H
+#define __ASM_RANDOM_H
+
+/* Out of line to avoid recursive include hell */
+unsigned long random_get_entropy(void);
+
+#endif
--- a/arch/arm64/include/asm/rqspinlock.h
+++ b/arch/arm64/include/asm/rqspinlock.h
@@ -2,6 +2,7 @@
 #ifndef _ASM_RQSPINLOCK_H
 #define _ASM_RQSPINLOCK_H
 
+#include <asm/arch_timer.h>
 #include <asm/barrier.h>
 
 /*
--- a/arch/arm64/include/asm/timex.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2012 ARM Ltd.
- */
-#ifndef __ASM_TIMEX_H
-#define __ASM_TIMEX_H
-
-#include <asm/arch_timer.h>
-
-/*
- * Use the current timer as a cycle counter since this is what we use for
- * the delay loop.
- */
-#define get_cycles()	arch_timer_read_counter()
-
-#include <asm-generic/timex.h>
-
-#endif
--- a/arch/arm64/kernel/time.c
+++ b/arch/arm64/kernel/time.c
@@ -29,6 +29,7 @@
 
 #include <clocksource/arm_arch_timer.h>
 
+#include <asm/arch_timer.h>
 #include <asm/thread_info.h>
 #include <asm/paravirt.h>
 
@@ -52,6 +53,11 @@ unsigned long profile_pc(struct pt_regs
 }
 EXPORT_SYMBOL(profile_pc);
 
+static unsigned long random_get_entropy(void)
+{
+	return arch_timer_read_counter();
+}
+
 void __init time_init(void)
 {
 	u32 arch_timer_rate;
--- a/arch/arm64/kernel/topology.c
+++ b/arch/arm64/kernel/topology.c
@@ -21,6 +21,7 @@
 #include <linux/sched/isolation.h>
 #include <linux/xarray.h>
 
+#include <asm/arch_timer.h>
 #include <asm/cpu.h>
 #include <asm/cputype.h>
 #include <asm/topology.h>
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -30,6 +30,7 @@
 #include <linux/ubsan.h>
 #include <linux/cfi.h>
 
+#include <asm/arch_timer.h>
 #include <asm/atomic.h>
 #include <asm/bug.h>
 #include <asm/cpufeature.h>
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -7,6 +7,7 @@
 #include <linux/kvm.h>
 #include <linux/kvm_host.h>
 
+#include <asm/arch_timer.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_nested.h>
 
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -18,6 +18,7 @@
 
 #include <kvm/arm_psci.h>
 
+#include <asm/arch_timer.h>
 #include <asm/barrier.h>
 #include <asm/cpufeature.h>
 #include <asm/extable.h>
--- a/arch/arm64/lib/delay.c
+++ b/arch/arm64/lib/delay.c
@@ -14,6 +14,7 @@
 #include <linux/timex.h>
 
 #include <clocksource/arm_arch_timer.h>
+#include <asm/arch_timer.h>
 
 #define USECS_TO_CYCLES(time_usecs)			\
 	xloops_to_cycles((time_usecs) * 0x10C7UL)
--- a/drivers/irqchip/irq-apple-aic.c
+++ b/drivers/irqchip/irq-apple-aic.c
@@ -55,6 +55,7 @@
 #include <linux/jump_label.h>
 #include <linux/limits.h>
 #include <linux/of_address.h>
+#include <asm/arch_timer.h>
 #include <linux/slab.h>
 #include <asm/apple_m1_pmu.h>
 #include <asm/cputype.h>

[patch 26/38] loongarch: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch loongarch over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: loongarch@lists.linux.dev
---
 arch/loongarch/Kconfig              |    1 +
 arch/loongarch/include/asm/random.h |   15 +++++++++++++++
 arch/loongarch/kernel/syscall.c     |    1 +
 arch/loongarch/lib/delay.c          |    2 +-
 4 files changed, 18 insertions(+), 1 deletion(-)

--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -26,6 +26,7 @@ config LOONGARCH
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_SET_DIRECT_MAP
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
--- /dev/null
+++ b/arch/loongarch/include/asm/random.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_RANDOM_H
+#define _ASM_RANDOM_H
+
+#include <asm/timex.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	return get_cycles();
+}
+
+#endif /*  _ASM_RANDOM_H */
--- a/arch/loongarch/kernel/syscall.c
+++ b/arch/loongarch/kernel/syscall.c
@@ -19,6 +19,7 @@
 #include <asm/loongarch.h>
 #include <asm/signal.h>
 #include <asm/switch_to.h>
+#include <asm/timex.h>
 #include <asm-generic/syscalls.h>
 
 #undef __SYSCALL
--- a/arch/loongarch/lib/delay.c
+++ b/arch/loongarch/lib/delay.c
@@ -5,9 +5,9 @@
 #include <linux/delay.h>
 #include <linux/export.h>
 #include <linux/smp.h>
-#include <linux/timex.h>
 
 #include <asm/processor.h>
+#include <asm/timex.h>
 
 void __delay(unsigned long cycles)
 {

[patch 27/38] m68k: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide
random_get_entropy().

Switch m68k over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
providing random_get_entropy() in asm/random.h.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
---
 arch/m68k/Kconfig              |    1 +
 arch/m68k/amiga/config.c       |    1 +
 arch/m68k/include/asm/random.h |   14 ++++++++++++++
 arch/m68k/include/asm/timex.h  |   25 -------------------------
 arch/m68k/kernel/time.c        |    2 +-
 5 files changed, 17 insertions(+), 26 deletions(-)

--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -8,6 +8,7 @@ config M68K
 	select ARCH_HAS_CPU_FINALIZE_INIT if MMU
 	select ARCH_HAS_CURRENT_STACK_POINTER
 	select ARCH_HAS_DMA_PREP_COHERENT if M68K_NONCOHERENT_DMA && !COLDFIRE
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if M68K_NONCOHERENT_DMA
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS
 	select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
--- a/arch/m68k/amiga/config.c
+++ b/arch/m68k/amiga/config.c
@@ -36,6 +36,7 @@
 #include <asm/machdep.h>
 #include <asm/io.h>
 #include <asm/config.h>
+#include <asm/random.h>
 
 #include "amiga.h"
 
--- /dev/null
+++ b/arch/m68k/include/asm/random.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASMm68K_RANDOM_H
+#define _ASMm68K_RANDOM_H
+
+extern unsigned long (*mach_random_get_entropy)(void);
+
+static inline unsigned long random_get_entropy(void)
+{
+	if (mach_random_get_entropy)
+		return mach_random_get_entropy();
+	return random_get_entropy_fallback();
+}
+
+#endif
--- a/arch/m68k/include/asm/timex.h
+++ /dev/null
@@ -1,25 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * linux/include/asm-m68k/timex.h
- *
- * m68k architecture timex specifications
- */
-#ifndef _ASMm68K_TIMEX_H
-#define _ASMm68K_TIMEX_H
-
-static inline cycles_t get_cycles(void)
-{
-	return 0;
-}
-
-extern unsigned long (*mach_random_get_entropy)(void);
-
-static inline unsigned long random_get_entropy(void)
-{
-	if (mach_random_get_entropy)
-		return mach_random_get_entropy();
-	return random_get_entropy_fallback();
-}
-#define random_get_entropy	random_get_entropy
-
-#endif
--- a/arch/m68k/kernel/time.c
+++ b/arch/m68k/kernel/time.c
@@ -26,12 +26,12 @@
 #include <asm/machdep.h>
 #include <asm/io.h>
 #include <asm/irq_regs.h>
+#include <asm/random.h>
 
 #include <linux/time.h>
 #include <linux/timex.h>
 #include <linux/profile.h>
 
-
 unsigned long (*mach_random_get_entropy)(void);
 EXPORT_SYMBOL_GPL(mach_random_get_entropy);
 

Re: [patch 27/38] m68k: Select ARCH_HAS_RANDOM_ENTROPY

[Daniel Palmer]

Hi

On Fri, 10 Apr 2026 at 21:39, Thomas Gleixner <tglx@kernel.org> wrote:
>
> The only remaining usage of get_cycles() is to provide
> random_get_entropy().
>
> Switch m68k over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
> providing random_get_entropy() in asm/random.h.

I have built and booted this on my Amiga 4000 and it apparently still
works so FWIW:

Tested-by: Daniel Palmer <daniel@thingy.jp>

[patch 28/38] mips: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide random_get_entropy().

Switch mips over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

As a consequence this unearthed a nasty include dependency hell because
arbitrary code relies on a magic include of asm/timex.h. Including the
headers in asm/random.h turned out to be impossible as well.

The only solution for now is to uninline random_get_entropy().  Fix up all
other dependencies on the content of asm/timex.h in those files which
really depend on it.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 arch/mips/Kconfig              |    1 
 arch/mips/generic/init.c       |    1 
 arch/mips/include/asm/random.h |    7 +++
 arch/mips/include/asm/timex.h  |   92 -----------------------------------------
 arch/mips/kernel/pm-cps.c      |    1 
 arch/mips/kernel/proc.c        |    1 
 arch/mips/kernel/relocate.c    |    1 
 arch/mips/kernel/time.c        |   53 +++++++++++++++++++++++
 arch/mips/lib/dump_tlb.c       |    1 
 arch/mips/mm/cache.c           |    1 
 10 files changed, 66 insertions(+), 93 deletions(-)

--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -19,6 +19,7 @@ config MIPS
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UBSAN
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_KEEP_MEMBLOCK
 	select ARCH_USE_BUILTIN_BSWAP
 	select ARCH_USE_CMPXCHG_LOCKREF if 64BIT
--- a/arch/mips/generic/init.c
+++ b/arch/mips/generic/init.c
@@ -12,6 +12,7 @@
 #include <linux/of_fdt.h>
 
 #include <asm/bootinfo.h>
+#include <asm/cpu-type.h>
 #include <asm/fw/fw.h>
 #include <asm/irq_cpu.h>
 #include <asm/machine.h>
--- /dev/null
+++ b/arch/mips/include/asm/random.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-v2.0-only */
+#ifndef _ASM_RANDOM_H
+#define _ASM_RANDOM_H
+
+unsigned long random_get_entropy(void);
+
+#endif /*  _ASM_RANDOM_H */
--- a/arch/mips/include/asm/timex.h
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 1998, 1999, 2003 by Ralf Baechle
- * Copyright (C) 2014 by Maciej W. Rozycki
- */
-#ifndef _ASM_TIMEX_H
-#define _ASM_TIMEX_H
-
-#ifdef __KERNEL__
-
-#include <linux/compiler.h>
-
-#include <asm/cpu.h>
-#include <asm/cpu-features.h>
-#include <asm/mipsregs.h>
-#include <asm/cpu-type.h>
-
-/*
- * Standard way to access the cycle counter.
- * Currently only used on SMP for scheduling.
- *
- * Only the low 32 bits are available as a continuously counting entity.
- * But this only means we'll force a reschedule every 8 seconds or so,
- * which isn't an evil thing.
- *
- * We know that all SMP capable CPUs have cycle counters.
- */
-
-/*
- * On R4000/R4400 an erratum exists such that if the cycle counter is
- * read in the exact moment that it is matching the compare register,
- * no interrupt will be generated.
- *
- * There is a suggested workaround and also the erratum can't strike if
- * the compare interrupt isn't being used as the clock source device.
- * However for now the implementation of this function doesn't get these
- * fine details right.
- */
-static inline int can_use_mips_counter(unsigned int prid)
-{
-	int comp = (prid & PRID_COMP_MASK) != PRID_COMP_LEGACY;
-
-	if (__builtin_constant_p(cpu_has_counter) && !cpu_has_counter)
-		return 0;
-	else if (__builtin_constant_p(cpu_has_mips_r) && cpu_has_mips_r)
-		return 1;
-	else if (likely(!__builtin_constant_p(cpu_has_mips_r) && comp))
-		return 1;
-	/* Make sure we don't peek at cpu_data[0].options in the fast path! */
-	if (!__builtin_constant_p(cpu_has_counter))
-		asm volatile("" : "=m" (cpu_data[0].options));
-	if (likely(cpu_has_counter &&
-		   prid > (PRID_IMP_R4000 | PRID_REV_ENCODE_44(15, 15))))
-		return 1;
-	else
-		return 0;
-}
-
-static inline cycles_t get_cycles(void)
-{
-	if (can_use_mips_counter(read_c0_prid()))
-		return read_c0_count();
-	else
-		return 0;	/* no usable counter */
-}
-#define get_cycles get_cycles
-
-/*
- * Like get_cycles - but where c0_count is not available we desperately
- * use c0_random in an attempt to get at least a little bit of entropy.
- */
-static inline unsigned long random_get_entropy(void)
-{
-	unsigned int c0_random;
-
-	if (can_use_mips_counter(read_c0_prid()))
-		return read_c0_count();
-
-	if (cpu_has_3kex)
-		c0_random = (read_c0_random() >> 8) & 0x3f;
-	else
-		c0_random = read_c0_random() & 0x3f;
-	return (random_get_entropy_fallback() << 6) | (0x3f - c0_random);
-}
-#define random_get_entropy random_get_entropy
-
-#endif /* __KERNEL__ */
-
-#endif /*  _ASM_TIMEX_H */
--- a/arch/mips/kernel/pm-cps.c
+++ b/arch/mips/kernel/pm-cps.c
@@ -13,6 +13,7 @@
 #include <asm/asm-offsets.h>
 #include <asm/cacheflush.h>
 #include <asm/cacheops.h>
+#include <asm/cpu-type.h>
 #include <asm/idle.h>
 #include <asm/mips-cps.h>
 #include <asm/mipsmtregs.h>
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -11,6 +11,7 @@
 #include <asm/bootinfo.h>
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
+#include <asm/cpu-type.h>
 #include <asm/idle.h>
 #include <asm/mipsregs.h>
 #include <asm/processor.h>
--- a/arch/mips/kernel/relocate.c
+++ b/arch/mips/kernel/relocate.c
@@ -13,7 +13,6 @@
 #include <asm/fw/fw.h>
 #include <asm/sections.h>
 #include <asm/setup.h>
-#include <asm/timex.h>
 #include <linux/elf.h>
 #include <linux/kernel.h>
 #include <linux/libfdt.h>
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -2,6 +2,7 @@
 /*
  * Copyright 2001 MontaVista Software Inc.
  * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ * Copyright (C) 1998, 1999, 2003 by Ralf Baechle
  * Copyright (c) 2003, 2004  Maciej W. Rozycki
  *
  * Common time service routines for MIPS machines.
@@ -21,9 +22,12 @@
 #include <linux/cpufreq.h>
 #include <linux/delay.h>
 
+#include <asm/cpu.h>
 #include <asm/cpu-features.h>
 #include <asm/cpu-type.h>
 #include <asm/div64.h>
+#include <asm/mipsregs.h>
+#include <asm/random.h>
 #include <asm/time.h>
 
 #ifdef CONFIG_CPU_FREQ
@@ -150,6 +154,55 @@ static __init int cpu_has_mfc0_count_bug
 	return 0;
 }
 
+
+/*
+ * On R4000/R4400 an erratum exists such that if the cycle counter is
+ * read in the exact moment that it is matching the compare register,
+ * no interrupt will be generated.
+ *
+ * There is a suggested workaround and also the erratum can't strike if
+ * the compare interrupt isn't being used as the clock source device.
+ * However for now the implementation of this function doesn't get these
+ * fine details right.
+ */
+static inline int can_use_mips_counter(unsigned int prid)
+{
+	int comp = (prid & PRID_COMP_MASK) != PRID_COMP_LEGACY;
+
+	if (__builtin_constant_p(cpu_has_counter) && !cpu_has_counter)
+		return 0;
+	else if (__builtin_constant_p(cpu_has_mips_r) && cpu_has_mips_r)
+		return 1;
+	else if (likely(!__builtin_constant_p(cpu_has_mips_r) && comp))
+		return 1;
+	/* Make sure we don't peek at cpu_data[0].options in the fast path! */
+	if (!__builtin_constant_p(cpu_has_counter))
+		asm volatile("" : "=m" (cpu_data[0].options));
+	if (likely(cpu_has_counter &&
+		   prid > (PRID_IMP_R4000 | PRID_REV_ENCODE_44(15, 15))))
+		return 1;
+	else
+		return 0;
+}
+
+/*
+ * Like get_cycles - but where c0_count is not available we desperately
+ * use c0_random in an attempt to get at least a little bit of entropy.
+ */
+unsigned long random_get_entropy(void)
+{
+	unsigned int c0_random;
+
+	if (can_use_mips_counter(read_c0_prid()))
+		return read_c0_count();
+
+	if (cpu_has_3kex)
+		c0_random = (read_c0_random() >> 8) & 0x3f;
+	else
+		c0_random = read_c0_random() & 0x3f;
+	return (random_get_entropy_fallback() << 6) | (0x3f - c0_random);
+}
+
 void __init time_init(void)
 {
 	plat_time_init();
--- a/arch/mips/lib/dump_tlb.c
+++ b/arch/mips/lib/dump_tlb.c
@@ -8,6 +8,7 @@
 #include <linux/kernel.h>
 #include <linux/mm.h>
 
+#include <asm/cpu-type.h>
 #include <asm/hazards.h>
 #include <asm/mipsregs.h>
 #include <asm/mmu_context.h>
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -22,6 +22,7 @@
 #include <asm/processor.h>
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
+#include <asm/cpu-type.h>
 #include <asm/setup.h>
 #include <asm/pgtable.h>
 

[patch 29/38] nios2: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch nios2 over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Dinh Nguyen <dinguyen@kernel.org>
---
 arch/nios2/Kconfig              |    1 +
 arch/nios2/include/asm/random.h |   14 ++++++++++++++
 arch/nios2/include/asm/timex.h  |    5 +----
 arch/nios2/kernel/time.c        |    4 ++--
 4 files changed, 18 insertions(+), 6 deletions(-)

--- a/arch/nios2/Kconfig
+++ b/arch/nios2/Kconfig
@@ -7,6 +7,7 @@ config NIOS2
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_HAS_DMA_SET_UNCACHED
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_NO_SWAP
 	select COMMON_CLK
 	select TIMER_OF
--- /dev/null
+++ b/arch/nios2/include/asm/random.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_NIOS2_RANDOM_H
+#define _ASM_NIOS2_RANDOM_H
+
+#include <asm/timex.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	unsigned long c = get_cycles();
+
+	return c ? c : random_get_entropy_fallback();
+}
+
+#endif
--- a/arch/nios2/include/asm/timex.h
+++ b/arch/nios2/include/asm/timex.h
@@ -5,9 +5,6 @@
 #ifndef _ASM_NIOS2_TIMEX_H
 #define _ASM_NIOS2_TIMEX_H
 
-extern cycles_t get_cycles(void);
-#define get_cycles get_cycles
-
-#define random_get_entropy() (((unsigned long)get_cycles()) ?: random_get_entropy_fallback())
+cycles_t get_cycles(void);
 
 #endif
--- a/arch/nios2/kernel/time.c
+++ b/arch/nios2/kernel/time.c
@@ -7,7 +7,6 @@
  * License. See the file "COPYING" in the main directory of this archive
  * for more details.
  */
-
 #include <linux/export.h>
 #include <linux/interrupt.h>
 #include <linux/clockchips.h>
@@ -19,6 +18,8 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 
+#include <asm/timex.h>
+
 #define ALTR_TIMER_COMPATIBLE		"altr,timer-1.0"
 
 #define ALTERA_TIMER_STATUS_REG	0
@@ -112,7 +113,6 @@ cycles_t get_cycles(void)
 		return nios2_timer_read(&nios2_cs.cs);
 	return 0;
 }
-EXPORT_SYMBOL(get_cycles);
 
 static void nios2_timer_start(struct nios2_timer *timer)
 {

[patch 30/38] openrisc: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch openrisc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: linux-openrisc@vger.kernel.org
---
 arch/openrisc/Kconfig              |    1 +
 arch/openrisc/include/asm/random.h |   12 ++++++++++++
 arch/openrisc/include/asm/timex.h  |    5 -----
 arch/openrisc/lib/delay.c          |    1 +
 4 files changed, 14 insertions(+), 5 deletions(-)

--- a/arch/openrisc/Kconfig
+++ b/arch/openrisc/Kconfig
@@ -10,6 +10,7 @@ config OPENRISC
 	select ARCH_HAS_DELAY_TIMER
 	select ARCH_HAS_DMA_SET_UNCACHED
 	select ARCH_HAS_DMA_CLEAR_UNCACHED
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select GENERIC_BUILTIN_DTB
 	select COMMON_CLK
--- /dev/null
+++ b/arch/openrisc/include/asm/random.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __ASM_OPENRISC_RANDOM_H
+#define __ASM_OPENRISC_RANDOM_H
+
+#include <asm/timex.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	return get_cycles();
+}
+
+#endif
--- a/arch/openrisc/include/asm/timex.h
+++ b/arch/openrisc/include/asm/timex.h
@@ -9,13 +9,9 @@
  * OpenRISC implementation:
  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  */
-
 #ifndef __ASM_OPENRISC_TIMEX_H
 #define __ASM_OPENRISC_TIMEX_H
 
-#define get_cycles get_cycles
-
-#include <asm-generic/timex.h>
 #include <asm/spr.h>
 #include <asm/spr_defs.h>
 
@@ -23,6 +19,5 @@ static inline cycles_t get_cycles(void)
 {
 	return mfspr(SPR_TTCR);
 }
-#define get_cycles get_cycles
 
 #endif
--- a/arch/openrisc/lib/delay.c
+++ b/arch/openrisc/lib/delay.c
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 
 #include <asm/param.h>
+#include <asm/timex.h>
 #include <asm/processor.h>
 
 bool delay_read_timer(unsigned long *timer_value)

[patch 31/38] parisc: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch parisc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
---
 arch/parisc/Kconfig              |    1 +
 arch/parisc/include/asm/random.h |   12 ++++++++++++
 arch/parisc/include/asm/timex.h  |    6 ------
 arch/parisc/kernel/processor.c   |    1 +
 arch/parisc/kernel/time.c        |    1 +
 5 files changed, 15 insertions(+), 6 deletions(-)

--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -16,6 +16,7 @@ config PARISC
 	select ARCH_HAS_STRICT_MODULE_RWX
 	select ARCH_HAS_UBSAN
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_NO_SG_CHAIN
 	select ARCH_SPLIT_ARG64 if !64BIT
 	select ARCH_SUPPORTS_HUGETLBFS if PA20
--- /dev/null
+++ b/arch/parisc/include/asm/random.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASMPARISC_RANDOM_H
+#define _ASMPARISC_RANDOM_H
+
+#include <asm/timex.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	return get_cycles();
+}
+
+#endif
--- a/arch/parisc/include/asm/timex.h
+++ b/arch/parisc/include/asm/timex.h
@@ -1,9 +1,4 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-/*
- * linux/include/asm-parisc/timex.h
- *
- * PARISC architecture timex specifications
- */
 #ifndef _ASMPARISC_TIMEX_H
 #define _ASMPARISC_TIMEX_H
 
@@ -13,6 +8,5 @@ static inline cycles_t get_cycles(void)
 {
 	return mfctl(16);
 }
-#define get_cycles get_cycles
 
 #endif
--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -30,6 +30,7 @@
 #include <asm/pdcpat.h>
 #include <asm/irq.h>		/* for struct irq_region */
 #include <asm/parisc-device.h>
+#include <asm/timex.h>
 
 struct system_cpuinfo_parisc boot_cpu_data __ro_after_init;
 EXPORT_SYMBOL(boot_cpu_data);
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -17,6 +17,7 @@
 #include <linux/platform_device.h>
 #include <asm/processor.h>
 #include <asm/pdcpat.h>
+#include <asm/timex.h>
 
 static u64 cr16_clock_freq;
 static unsigned long clocktick;

[patch 32/38] powerpc/spufs: Use mftb() directly

[Thomas Gleixner]

There is no reason to indirect via get_cycles(), which is about to be
removed.

Use mftb() directly.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/platforms/cell/spufs/switch.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/arch/powerpc/platforms/cell/spufs/switch.c
+++ b/arch/powerpc/platforms/cell/spufs/switch.c
@@ -34,6 +34,7 @@
 #include <asm/spu_priv1.h>
 #include <asm/spu_csa.h>
 #include <asm/mmu_context.h>
+#include <asm/time.h>
 
 #include "spufs.h"
 
@@ -279,7 +280,7 @@ static inline void save_timebase(struct
 	 *    Read PPE Timebase High and Timebase low registers
 	 *    and save in CSA.  TBD.
 	 */
-	csa->suspend_time = get_cycles();
+	csa->suspend_time = mftb();
 }
 
 static inline void remove_other_spu_access(struct spu_state *csa,
@@ -1261,7 +1262,7 @@ static inline void setup_decr(struct spu
 	 *     in LSCSA.
 	 */
 	if (csa->priv2.mfc_control_RW & MFC_CNTL_DECREMENTER_RUNNING) {
-		cycles_t resume_time = get_cycles();
+		cycles_t resume_time = mftb();
 		cycles_t delta_time = resume_time - csa->suspend_time;
 
 		csa->lscsa->decr_status.slot[0] = SPU_DECR_STATUS_RUNNING;

[patch 33/38] powerpc: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide random_get_entropy().

Switch powerpc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/Kconfig              |    1 +
 arch/powerpc/include/asm/random.h |   13 +++++++++++++
 arch/powerpc/include/asm/timex.h  |   21 ---------------------
 3 files changed, 14 insertions(+), 21 deletions(-)

--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -150,6 +150,7 @@ config PPC
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX	if (PPC_BOOK3S || PPC_8xx) && !HIBERNATION
--- /dev/null
+++ b/arch/powerpc/include/asm/random.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_RANDOM_H
+#define _ASM_POWERPC_RANDOM_H
+
+#include <asm/cputable.h>
+#include <asm/vdso/timebase.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	return mftb();
+}
+
+#endif	/* _ASM_POWERPC_RANDOM_H */
--- a/arch/powerpc/include/asm/timex.h
+++ b/arch/powerpc/include/asm/timex.h
@@ -1,21 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_POWERPC_TIMEX_H
-#define _ASM_POWERPC_TIMEX_H
-
-#ifdef __KERNEL__
-
-/*
- * PowerPC architecture timex specifications
- */
-
-#include <asm/cputable.h>
-#include <asm/vdso/timebase.h>
-
-ostatic inline cycles_t get_cycles(void)
-{
-	return mftb();
-}
-#define get_cycles get_cycles
-
-#endif	/* __KERNEL__ */
-#endif	/* _ASM_POWERPC_TIMEX_H */

[patch 34/38] riscv: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch riscv over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: linux-riscv@lists.infradead.org
---
 arch/riscv/Kconfig                         |    1 +
 arch/riscv/include/asm/random.h            |   25 +++++++++++++++++++++++++
 arch/riscv/include/asm/timex.h             |   13 -------------
 arch/riscv/kernel/unaligned_access_speed.c |    1 +
 arch/riscv/kvm/vcpu_timer.c                |    1 +
 arch/riscv/lib/delay.c                     |    1 +
 6 files changed, 29 insertions(+), 13 deletions(-)

--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -47,6 +47,7 @@ config RISCV
 	select ARCH_HAS_PREPARE_SYNC_CORE_CMD
 	select ARCH_HAS_PTDUMP if MMU
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SET_DIRECT_MAP if MMU
 	select ARCH_HAS_SET_MEMORY if MMU
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
--- /dev/null
+++ b/arch/riscv/include/asm/random.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASM_RISCV_RANDOM_H
+#define _ASM_RISCV_RANDOM_H
+
+#include <asm/timex.h>
+
+#ifdef CONFIG_RISCV_M_MODE
+/*
+ * Much like MIPS, we may not have a viable counter to use at an early point
+ * in the boot process. Unfortunately we don't have a fallback, so instead
+ * invoke the fallback function.
+ */
+static inline unsigned long random_get_entropy(void)
+{
+	if (unlikely(clint_time_val == NULL))
+		return random_get_entropy_fallback();
+	return get_cycles();
+}
+#else  /* !CONFIG_RISCV_M_MODE */
+static inline unsigned long random_get_entropy(void)
+{
+	return get_cycles();
+}
+#endif /* CONFIG_RISCV_M_MODE */
+#endif /* _ASM_RISCV_RANDOM_H */
--- a/arch/riscv/include/asm/timex.h
+++ b/arch/riscv/include/asm/timex.h
@@ -31,19 +31,6 @@ static inline u32 get_cycles_hi(void)
 #define get_cycles_hi get_cycles_hi
 #endif /* CONFIG_64BIT */
 
-/*
- * Much like MIPS, we may not have a viable counter to use at an early point
- * in the boot process. Unfortunately we don't have a fallback, so instead
- * we just return 0.
- */
-static inline unsigned long random_get_entropy(void)
-{
-	if (unlikely(clint_time_val == NULL))
-		return random_get_entropy_fallback();
-	return get_cycles();
-}
-#define random_get_entropy()	random_get_entropy()
-
 #else /* CONFIG_RISCV_M_MODE */
 
 static inline cycles_t get_cycles(void)
--- a/arch/riscv/kernel/unaligned_access_speed.c
+++ b/arch/riscv/kernel/unaligned_access_speed.c
@@ -12,6 +12,7 @@
 #include <linux/types.h>
 #include <asm/cpufeature.h>
 #include <asm/hwprobe.h>
+#include <asm/timex.h>
 #include <asm/vector.h>
 
 #include "copy-unaligned.h"
--- a/arch/riscv/kvm/vcpu_timer.c
+++ b/arch/riscv/kvm/vcpu_timer.c
@@ -14,6 +14,7 @@
 #include <asm/delay.h>
 #include <asm/kvm_nacl.h>
 #include <asm/kvm_vcpu_timer.h>
+#include <asm/timex.h>
 
 static u64 kvm_riscv_current_cycles(struct kvm_guest_timer *gt)
 {
--- a/arch/riscv/lib/delay.c
+++ b/arch/riscv/lib/delay.c
@@ -10,6 +10,7 @@
 #include <linux/export.h>
 
 #include <asm/processor.h>
+#include <asm/timex.h>
 
 /*
  * This is copies from arch/arm/include/asm/delay.h

[patch 35/38] s390: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining non-architecture usage of get_cycles() is to provide
random_get_entropy().

Switch s390 over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
providing random_get_entropy() in asm/random.h.

Add 'asm/timex.h' includes to the relevant files, so the global include can
be removed once all architectures are converted over.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
---
 arch/s390/Kconfig              |    1 +
 arch/s390/include/asm/random.h |   12 ++++++++++++
 arch/s390/include/asm/timex.h  |    6 ------
 arch/s390/kernel/time.c        |    1 +
 arch/s390/kernel/vtime.c       |    1 +
 5 files changed, 15 insertions(+), 6 deletions(-)

--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -108,6 +108,7 @@ config S390
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_SCALED_CPUTIME
 	select ARCH_HAS_SET_DIRECT_MAP
 	select ARCH_HAS_SET_MEMORY
--- /dev/null
+++ b/arch/s390/include/asm/random.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_RANDOM_H
+#define _ASM_S390_RANDOM_H
+
+#include <asm/timex.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	return (unsigned long)get_tod_clock_monotonic() >> 2;
+}
+
+#endif
--- a/arch/s390/include/asm/timex.h
+++ b/arch/s390/include/asm/timex.h
@@ -219,12 +219,6 @@ static inline unsigned long get_tod_cloc
 	return tod;
 }
 
-static inline cycles_t get_cycles(void)
-{
-	return (cycles_t)get_tod_clock_monotonic() >> 2;
-}
-#define get_cycles get_cycles
-
 /**
  * tod_to_ns - convert a TOD format value to nanoseconds
  * @todval: to be converted TOD format value
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -50,6 +50,7 @@
 #include <asm/irq_regs.h>
 #include <asm/vtimer.h>
 #include <asm/stp.h>
+#include <asm/timex.h>
 #include <asm/cio.h>
 #include "entry.h"
 
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -14,6 +14,7 @@
 #include <linux/time.h>
 #include <asm/alternative.h>
 #include <asm/cputime.h>
+#include <asm/timex.h>
 #include <asm/vtimer.h>
 #include <asm/vtime.h>
 #include <asm/cpu_mf.h>

[patch 36/38] sparc: Select ARCH_HAS_RANDOM_ENTROPY for SPARC64

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide random_get_entropy().

Switch sparc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
and providing random_get_entropy() in asm/random.h.

Remove asm/timex*.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
---
 arch/sparc/Kconfig                |    1 +
 arch/sparc/include/asm/random.h   |   15 +++++++++++++++
 arch/sparc/include/asm/timex.h    |    9 ---------
 arch/sparc/include/asm/timex_64.h |   15 ---------------
 arch/sparc/kernel/pcic.c          |    1 -
 arch/sparc/kernel/time_32.c       |    1 -
 arch/sparc/vdso/vclock_gettime.c  |    1 -
 7 files changed, 16 insertions(+), 27 deletions(-)

--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -71,6 +71,7 @@ config SPARC64
 	def_bool 64BIT
 	select ALTERNATE_USER_ADDRESS_SPACE
 	select ARCH_HAS_DELAY_TIMER
+	select ARCH_HAS_RANDOM_ENTROPY
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_KRETPROBES
--- /dev/null
+++ b/arch/sparc/include/asm/random.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef _ASMsparc_RANDOM_H
+#define _ASMsparc_RANDOM_H
+
+#if defined(__sparc__) && defined(__arch64__)
+
+#include <asm/timer.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	return tick_ops->get_tick();
+}
+
+#endif
+#endif
--- a/arch/sparc/include/asm/timex.h
+++ /dev/null
@@ -1,9 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef ___ASM_SPARC_TIMEX_H
-#define ___ASM_SPARC_TIMEX_H
-#if defined(__sparc__) && defined(__arch64__)
-#include <asm/timex_64.h>
-#else
-#include <asm-generic/timex.h>
-#endif
-#endif
--- a/arch/sparc/include/asm/timex_64.h
+++ b/arch/sparc/include/asm/timex_64.h
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * linux/include/asm/timex.h
- *
- * sparc64 architecture timex specifications
- */
-#ifndef _ASMsparc64_TIMEX_H
-#define _ASMsparc64_TIMEX_H
-
-#include <asm/timer.h>
-
-/* Getting on the cycle counter on sparc64. */
-#define get_cycles()	tick_ops->get_tick()
-
-#endif
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -33,7 +33,6 @@
 #include <asm/oplib.h>
 #include <asm/prom.h>
 #include <asm/pcic.h>
-#include <asm/timex.h>
 #include <asm/timer.h>
 #include <linux/uaccess.h>
 #include <asm/irq_regs.h>
--- a/arch/sparc/kernel/time_32.c
+++ b/arch/sparc/kernel/time_32.c
@@ -37,7 +37,6 @@
 
 #include <asm/mc146818rtc.h>
 #include <asm/oplib.h>
-#include <asm/timex.h>
 #include <asm/timer.h>
 #include <asm/irq.h>
 #include <asm/io.h>
--- a/arch/sparc/vdso/vclock_gettime.c
+++ b/arch/sparc/vdso/vclock_gettime.c
@@ -17,7 +17,6 @@
 #include <linux/string.h>
 #include <asm/io.h>
 #include <asm/unistd.h>
-#include <asm/timex.h>
 #include <asm/clocksource.h>
 #include <asm/vvar.h>
 

[patch 37/38] x86: Select ARCH_HAS_RANDOM_ENTROPY

[Thomas Gleixner]

The only remaining usage of get_cycles() is to provide random_get_entropy().

Switch x86 over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY and
providing random_get_entropy() in asm/random.h.

Remove asm/timex.h as it has no functionality anymore.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Cc: x86@kernel.org
---
 arch/x86/Kconfig              |    1 +
 arch/x86/include/asm/random.h |   16 ++++++++++++++++
 arch/x86/include/asm/timex.h  |   17 -----------------
 arch/x86/include/asm/tsc.h    |    9 ---------
 4 files changed, 17 insertions(+), 26 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -101,6 +101,7 @@ config X86
 	select ARCH_HAS_PREEMPT_LAZY
 	select ARCH_HAS_PTDUMP
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_RANDOM_ENTROPY
 	select ARCH_HAS_HW_PTE_YOUNG
 	select ARCH_HAS_NONLEAF_PMD_YOUNG	if PGTABLE_LEVELS > 2
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if X86_64
--- /dev/null
+++ b/arch/x86/include/asm/random.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_RANDOM_H
+#define _ASM_X86_RANDOM_H
+
+#include <asm/processor.h>
+#include <asm/tsc.h>
+
+static inline unsigned long random_get_entropy(void)
+{
+	if (!IS_ENABLED(CONFIG_X86_TSC) &&
+	    !cpu_feature_enabled(X86_FEATURE_TSC))
+		return random_get_entropy_fallback();
+	return rdtsc();
+}
+
+#endif /* _ASM_X86_RANDOM_H */
--- a/arch/x86/include/asm/timex.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_X86_TIMEX_H
-#define _ASM_X86_TIMEX_H
-
-#include <asm/processor.h>
-#include <asm/tsc.h>
-
-static inline unsigned long random_get_entropy(void)
-{
-	if (!IS_ENABLED(CONFIG_X86_TSC) &&
-	    !cpu_feature_enabled(X86_FEATURE_TSC))
-		return random_get_entropy_fallback();
-	return rdtsc();
-}
-#define random_get_entropy random_get_entropy
-
-#endif /* _ASM_X86_TIMEX_H */
--- a/arch/x86/include/asm/tsc.h
+++ b/arch/x86/include/asm/tsc.h
@@ -72,15 +72,6 @@ extern unsigned int tsc_khz;
 
 extern void disable_TSC(void);
 
-static inline cycles_t get_cycles(void)
-{
-	if (!IS_ENABLED(CONFIG_X86_TSC) &&
-	    !cpu_feature_enabled(X86_FEATURE_TSC))
-		return 0;
-	return rdtsc();
-}
-#define get_cycles get_cycles
-
 extern void tsc_early_init(void);
 extern void tsc_init(void);
 extern void mark_tsc_unstable(char *reason);

[patch 38/38] treewide: Remove asm/timex.h includes from generic code

[Thomas Gleixner]

asm/timex.h does not provide any functionality for non-architecture code
anymore.

Remove the asm-generic fallback and all references in include and source
files along with the random_get_entropy() #ifdeffery in timex.h.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
 include/asm-generic/Kbuild  |    1 -
 include/asm-generic/timex.h |   15 ---------------
 include/linux/random.h      |    3 +++
 include/linux/timex.h       |   26 --------------------------
 kernel/time/timer.c         |    1 -
 lib/interval_tree_test.c    |    1 -
 lib/rbtree_test.c           |    1 -
 7 files changed, 3 insertions(+), 45 deletions(-)

--- a/include/asm-generic/Kbuild
+++ b/include/asm-generic/Kbuild
@@ -56,7 +56,6 @@ mandatory-y += shmparam.h
 mandatory-y += simd.h
 mandatory-y += softirq_stack.h
 mandatory-y += switch_to.h
-mandatory-y += timex.h
 mandatory-y += tlbflush.h
 mandatory-y += topology.h
 mandatory-y += trace_clock.h
--- a/include/asm-generic/timex.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ASM_GENERIC_TIMEX_H
-#define __ASM_GENERIC_TIMEX_H
-
-/*
- * If you have a cycle counter, return the value here.
- */
-#ifndef get_cycles
-static inline cycles_t get_cycles(void)
-{
-	return 0;
-}
-#endif
-
-#endif /* __ASM_GENERIC_TIMEX_H */
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -1,3 +1,4 @@
+
 /* SPDX-License-Identifier: GPL-2.0 */
 
 #ifndef _LINUX_RANDOM_H
@@ -152,6 +153,8 @@ unsigned long random_get_entropy_fallbac
  */
 #ifdef CONFIG_ARCH_HAS_RANDOM_ENTROPY
 #include <asm/random.h>
+#else
+#define random_get_entropy()	random_get_entropy_fallback()
 #endif
 
 #endif /* _LINUX_RANDOM_H */
--- a/include/linux/timex.h
+++ b/include/linux/timex.h
@@ -62,32 +62,6 @@
 #include <linux/types.h>
 #include <linux/param.h>
 
-unsigned long random_get_entropy_fallback(void);
-
-#include <asm/timex.h>
-
-#ifndef CONFIG_ARCH_HAS_RANDOM_ENTROPY
-#ifndef random_get_entropy
-/*
- * The random_get_entropy() function is used by the /dev/random driver
- * in order to extract entropy via the relative unpredictability of
- * when an interrupt takes places versus a high speed, fine-grained
- * timing source or cycle counter.  Since it will be occurred on every
- * single interrupt, it must have a very low cost/overhead.
- *
- * By default we use get_cycles() for this purpose, but individual
- * architectures may override this in their asm/timex.h header file.
- * If a given arch does not have get_cycles(), then we fallback to
- * using random_get_entropy_fallback().
- */
-#ifdef get_cycles
-#define random_get_entropy()	((unsigned long)get_cycles())
-#else
-#define random_get_entropy()	random_get_entropy_fallback()
-#endif
-#endif
-#endif
-
 /*
  * SHIFT_PLL is used as a dampening factor to define how much we
  * adjust the frequency correction for a given offset in PLL mode.
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -48,7 +48,6 @@
 #include <linux/uaccess.h>
 #include <asm/unistd.h>
 #include <asm/div64.h>
-#include <asm/timex.h>
 #include <asm/io.h>
 
 #include "tick-internal.h"
--- a/lib/interval_tree_test.c
+++ b/lib/interval_tree_test.c
@@ -4,7 +4,6 @@
 #include <linux/interval_tree.h>
 #include <linux/prandom.h>
 #include <linux/slab.h>
-#include <asm/timex.h>
 #include <linux/bitmap.h>
 #include <linux/maple_tree.h>
 
--- a/lib/rbtree_test.c
+++ b/lib/rbtree_test.c
@@ -4,7 +4,6 @@
 #include <linux/rbtree_augmented.h>
 #include <linux/prandom.h>
 #include <linux/slab.h>
-#include <asm/timex.h>
 
 #define __param(type, name, init, msg)		\
 	static type name = init;		\