Commit Graph

5 Commits

Author SHA1 Message Date
Thomas Gleixner d28ede8379 timekeeping: Create struct tk_read_base and use it in struct timekeeper
The members of the new struct are the required ones for the new NMI
safe accessor to clcok monotonic. In order to reuse the existing
timekeeping code and to make the update of the fast NMI safe
timekeepers a simple memcpy use the struct for the timekeeper as well
and convert all users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:53 -07:00
Thomas Gleixner 4a0e637738 clocksource: Get rid of cycle_last
cycle_last was added to the clocksource to support the TSC
validation. We moved that to the core code, so we can get rid of the
extra copy.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-07-23 15:01:52 -07:00
Boris Ostrovsky 28b92e09e2 x86, vdso, time: Cast tv_nsec to u64 for proper shifting in update_vsyscall()
With tk->wall_to_monotonic.tv_nsec being a 32-bit value on 32-bit
systems, (tk->wall_to_monotonic.tv_nsec << tk->shift) in update_vsyscall()
may lose upper bits or, worse, add them since compiler will do this:
	(u64)(tk->wall_to_monotonic.tv_nsec << tk->shift)
instead of
	((u64)tk->wall_to_monotonic.tv_nsec << tk->shift)

So if, for example, tv_nsec is 0x800000 and shift is 8 we will end up
with 0xffffffff80000000 instead of 0x80000000. And then we are stuck in
the subsequent 'while' loop.

We need an explicit cast.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1399648287-15178-1-git-send-email-boris.ostrovsky@oracle.com
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2014-05-09 08:45:52 -07:00
Stefani Seibold 7c03156f34 x86, vdso: Add 32 bit VDSO time support for 64 bit kernel
This patch add the VDSO time support for the IA32 Emulation Layer.

Due the nature of the kernel headers and the LP64 compiler where the
size of a long and a pointer differs against a 32 bit compiler, there
is some type hacking necessary for optimal performance.

The vsyscall_gtod_data struture must be a rearranged to serve 32- and
64-bit code access at the same time:

- The seqcount_t was replaced by an unsigned, this makes the
  vsyscall_gtod_data intedepend of kernel configuration and internal functions.
- All kernel internal structures are replaced by fix size elements
  which works for 32- and 64-bit access
- The inner struct clock was removed to pack the whole struct.

The "unsigned seq" would be handled by functions derivated from seqcount_t.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-11-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18 12:52:41 -07:00
Stefani Seibold d2312e3379 x86, vdso: Make vsyscall_gtod_data handling x86 generic
This patch move the vsyscall_gtod_data handling out of vsyscall_64.c
into an additonal file vsyscall_gtod.c to make the functionality
available for x86 32 bit kernel.

It also adds a new vsyscall_32.c which setup the VVAR page.

Reviewed-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-2-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-03-18 12:51:52 -07:00