9 Commits

Author SHA1 Message Date
Thomas Gleixner
4c5a116ada vdso/treewide: Add vdso_data pointer argument to __arch_get_hw_counter()
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
2020-08-06 10:57:30 +02:00
Will Deacon
002dff36ac asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h'
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>
2020-07-21 10:50:36 +01:00
Vincenzo Frascino
78c8516141 arm: vdso: Enable arm to use common headers
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
2020-03-21 15:24:03 +01:00
Thomas Gleixner
5e3c6a312a ARM/arm64: vdso: Use common vdso clock mode storage
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
2020-02-17 20:12:16 +01:00
Thomas Gleixner
3280badbe1 ARM: vdso: Compile high resolution parts conditionally
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
2020-02-17 14:40:21 +01:00
Thomas Gleixner
715f23b610 ARM: vdso: Set BUILD_VDSO32 and provide 32bit fallbacks
Setting BUILD_VDSO32 is required to expose the legacy 32bit interfaces in
the generic VDSO code which are going to be hidden behind an #ifdef
BUILD_VDSO32.

The 32bit fallbacks are necessary to remove the existing
VDSO_HAS_32BIT_FALLBACK hackery.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/87tv4zq9dc.fsf@nanos.tec.linutronix.de
2020-01-14 12:20:43 +01:00
Vincenzo Frascino
04bb96427d ARM: 8947/1: Fix __arch_get_hw_counter() access to CNTVCT
__arch_get_hw_counter() should check clock_mode to see if it can access
CNTVCT. With the conversion to unified vDSO this check has been left out.

This causes on imx v6 and v7 (imx_v6_v7_defconfig) and other platforms to
hang at boot during the execution of the init process as per below:

[   19.976852] Run /sbin/init as init process
[   20.044931] Kernel panic - not syncing: Attempted to kill init!
exitcode=0x00000004

Fix the problem verifying that clock_mode is set coherently before
accessing CNTVCT.

Investigated-by: Arnd Bergmann <arnd@arndb.de>

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-12-06 11:51:03 +00:00
Vincenzo Frascino
052e76a31b ARM: 8931/1: Add clock_getres entry point
The generic vDSO library provides an implementation of clock_getres() that
can be leveraged by each architecture.

Add clock_getres() entry point on arm to be on pair with arm64.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15 22:21:14 +00:00
Vincenzo Frascino
20e2fc4231 ARM: 8930/1: Add support for generic vDSO
The arm vDSO library requires some adaptations to take advantage of
the newly introduced generic vDSO library.

Introduce the following changes:
 - Modification vdso.c to be compliant with the common vdso datapage
 - Use of lib/vdso for gettimeofday
 - Implementation of elf note

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2019-11-15 22:21:12 +00:00