linux.git/arch/arm/include/asm/vdso, branch for-next Linux kernel source tree ARM: vdso: Remove assembly for datapage access 2024-11-02T11:37:33+00:00 Thomas Weißschuh thomas.weissschuh@linutronix.de 2024-10-10T07:01:09+00:00 2bb79470e5c87f211d05f0dd1c7a4291c9b7e1a4 vdso/datapage.h provides a hidden declaration for _vdso_data. When using it the compiler will automatically generate PC-relative accesses which avoids the need for a custom assembly-based accessor. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-7-b64f0842d512@linutronix.de 
vdso/datapage.h provides a hidden declaration for _vdso_data.
When using it the compiler will automatically generate PC-relative
accesses which avoids the need for a custom assembly-based accessor.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241010-vdso-generic-base-v1-7-b64f0842d512@linutronix.de
arm: vdso: Remove timekeeper includes 2024-10-15T15:50:29+00:00 Thomas Weißschuh thomas.weissschuh@linutronix.de 2024-10-10T15:44:45+00:00 d2caf94c0a94e32a0beb56beacaf380ad33124fb Since the generic VDSO clock mode storage is used, this header file is unused and can be removed. This avoids including a non-VDSO header while building the VDSO, which can lead to compilation errors. Also drop the comment which is out of date and in the wrong place. Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20241010-vdso-generic-arch_update_vsyscall-v1-2-7fe5a3ea4382@linutronix.de 
Since the generic VDSO clock mode storage is used, this header file is
unused and can be removed.

This avoids including a non-VDSO header while building the VDSO,
which can lead to compilation errors.

Also drop the comment which is out of date and in the wrong place.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20241010-vdso-generic-arch_update_vsyscall-v1-2-7fe5a3ea4382@linutronix.de
vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter() 2020-08-06T08:57:30+00:00 Thomas Gleixner tglx@linutronix.de 2020-08-04T20:37:48+00:00 4c5a116ada953b86125ab7c70a57c57463a55a55 MIPS already uses and S390 will need the vdso data pointer in __arch_get_hw_counter(). This works nicely as long as the architecture does not support time namespaces in the VDSO. With time namespaces enabled the regular accessor to the vdso data pointer __arch_get_vdso_data() will return the namespace specific VDSO data page for tasks which are part of a non-root time namespace. This would cause the architectures which need the vdso data pointer in __arch_get_hw_counter() to access the wrong vdso data page. Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in from the call sites in the core code. For architectures which do not need the data pointer in their counter accessor function the compiler will just optimize it out. Fix up all existing architecture implementations and make MIPS utilize the pointer instead of invoking the accessor function. No functional change and no change in the resulting object code (except MIPS). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de 
MIPS already uses and S390 will need the vdso data pointer in
__arch_get_hw_counter().

This works nicely as long as the architecture does not support time
namespaces in the VDSO. With time namespaces enabled the regular
accessor to the vdso data pointer __arch_get_vdso_data() will return the
namespace specific VDSO data page for tasks which are part of a
non-root time namespace. This would cause the architectures which need
the vdso data pointer in __arch_get_hw_counter() to access the wrong
vdso data page.

Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in
from the call sites in the core code. For architectures which do not need
the data pointer in their counter accessor function the compiler will just
optimize it out.

Fix up all existing architecture implementations and make MIPS utilize the
pointer instead of invoking the accessor function.

No functional change and no change in the resulting object code (except
MIPS).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de
asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h' 2020-07-21T09:50:36+00:00 Will Deacon will@kernel.org 2020-07-10T13:49:40+00:00 002dff36acfba3476b685a09f78ffb7c452f5951 Now that 'smp_read_barrier_depends()' has gone the way of the Norwegian Blue, drop the inclusion of <asm/barrier.h> in 'asm-generic/rwonce.h'. This requires fixups to some architecture vdso headers which were previously relying on 'asm/barrier.h' coming in via 'linux/compiler.h'. Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Will Deacon <will@kernel.org> 
Now that 'smp_read_barrier_depends()' has gone the way of the Norwegian
Blue, drop the inclusion of <asm/barrier.h> in 'asm-generic/rwonce.h'.

This requires fixups to some architecture vdso headers which were
previously relying on 'asm/barrier.h' coming in via 'linux/compiler.h'.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Will Deacon <will@kernel.org>
arm: vdso: Enable arm to use common headers 2020-03-21T14:24:03+00:00 Vincenzo Frascino vincenzo.frascino@arm.com 2020-03-20T14:53:49+00:00 78c8516141014cf6322ac899c3832f66612504bb Enable arm to use only the common headers in the implementation of the vDSO library. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@armlinux.org.uk> Link: https://lkml.kernel.org/r/20200320145351.32292-25-vincenzo.frascino@arm.com 
Enable arm to use only the common headers in the implementation
of the vDSO library.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lkml.kernel.org/r/20200320145351.32292-25-vincenzo.frascino@arm.com
arm: Introduce asm/vdso/clocksource.h 2020-03-21T14:23:54+00:00 Vincenzo Frascino vincenzo.frascino@arm.com 2020-03-20T14:53:30+00:00 c16b270b171177d1a602b270aef9bff45585bfa2 The vDSO library should only include the necessary headers required for a userspace library (UAPI and a minimal set of kernel headers). To make this possible it is necessary to isolate from the kernel headers the common parts that are strictly necessary to build the library. Introduce asm/vdso/clocksource.h to contain all the arm64 specific functions that are suitable for vDSO inclusion. This header will be required by a future patch that will generalize vdso/clocksource.h. Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@armlinux.org.uk> Link: https://lkml.kernel.org/r/20200320145351.32292-6-vincenzo.frascino@arm.com 
The vDSO library should only include the necessary headers required for
a userspace library (UAPI and a minimal set of kernel headers). To make
this possible it is necessary to isolate from the kernel headers the
common parts that are strictly necessary to build the library.

Introduce asm/vdso/clocksource.h to contain all the arm64 specific
functions that are suitable for vDSO inclusion.

This header will be required by a future patch that will generalize
vdso/clocksource.h.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lkml.kernel.org/r/20200320145351.32292-6-vincenzo.frascino@arm.com
lib/vdso: Avoid highres update if clocksource is not VDSO capable 2020-02-17T19:12:17+00:00 Thomas Gleixner tglx@linutronix.de 2020-02-07T12:39:00+00:00 c7a18100bdffdff440c7291db6e80863fab0461e If the current clocksource is not VDSO capable there is no point in updating the high resolution parts of the VDSO data. Replace the architecture specific check with a check for a VDSO capable clocksource and skip the update if there is none. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de 
If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de
ARM/arm64: vdso: Use common vdso clock mode storage 2020-02-17T19:12:16+00:00 Thomas Gleixner tglx@linutronix.de 2020-02-07T12:38:58+00:00 5e3c6a312a0946d2d83e32359612cbb925a8bed0 Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to happen in one go as they share the clocksource driver. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de 
Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de
ARM: vdso: Compile high resolution parts conditionally 2020-02-17T13:40:21+00:00 Thomas Gleixner tglx@linutronix.de 2020-02-07T12:38:51+00:00 3280badbe1b289622ce12b94d064ddb624cbaef1 If the architected timer is disabled in the kernel configuration then let the core VDSO code drop the high resolution parts at compile time. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124402.622587341@linutronix.de 
If the architected timer is disabled in the kernel configuration then let
the core VDSO code drop the high resolution parts at compile time.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.622587341@linutronix.de
ARM: vdso: Remove unused function 2020-02-17T13:40:20+00:00 Thomas Gleixner tglx@linutronix.de 2020-02-07T12:38:49+00:00 78560d41064ad3d377e3d1a1ee87526301f4e946 The function is nowhere used. Aside of that this check should only cover the high resolution parts of the VDSO which require a VDSO capable clocksource and not the complete functionality as the name suggests. Will be replaced with something more useful. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de 
The function is nowhere used. Aside of that this check should only cover
the high resolution parts of the VDSO which require a VDSO capable
clocksource and not the complete functionality as the name suggests. Will
be replaced with something more useful.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de