summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/vdso
AgeCommit message (Collapse)Author
2012-12-05arm64: vdso: rework __do_get_tspec register allocation and return shiftWill Deacon
In preparation for sub-ns precision in the vdso timespec maths, change the __do_get_tspec register allocation so that we return the clocksource shift value instead of the unused xtime tspec. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-12-05arm64: vdso: check sequence counter even for coarse realtime operationsWill Deacon
When returning coarse realtime values from clock_gettime, we must still check the sequence counter to ensure that the kernel does not update the vdso datapage whilst we are loading the coarse timespec as this could potentially result in time appearing to go backwards. This patch delays the coarse realtime check until after we have loaded successfully from the vdso datapage. This does mean that we always load the wtm timespec, but conditionalising the load and adding an extra sequence test is unlikely to buy us anything other than messy code, particularly as the sequence test implies a read barrier. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-12-05arm64: vdso: fix clocksource mask when extracting bottom 56 bitsWill Deacon
The generic timer clocksource has 56 bits of precision and as such must be masked appropriately after we have read it. The current mask generated by a movn instruction is off by 4 bits, so we accidentally include the top 4 bits in the final value. This patch fixes the broken mask. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-09-17arm64: VDSO supportWill Deacon
This patch adds VDSO support for 64-bit applications. The VDSO code is currently used for sys_rt_sigreturn() and optimised gettimeofday() (using the user-accessible generic counter). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>