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Stephen Boyd
d11ca916b8
sched_clock: Use seqcount instead of rolling our own We're going to increase the cyc value to 64 bits in the near future. Doing that is going to break the custom seqcount implementation in the sched_clock code because 64 bit numbers aren't guaranteed to be atomic. Replace the cyc_copy with a seqcount to avoid this problem. Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Git-commit: 85c3d2dd15be4d577a37ffb8bbbd019fc8e3280a Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git [imaund@codeaurora.org: resolve merge conflicts] Signed-off-by: Ian Maund <imaund@codeaurora.org> Change-Id: Ic30515ef65e5d3ec008f03ae020a9599e7c01fb2 sched_clock: Use an hrtimer instead of timer In the next patch we're going to increase the number of bits that the generic sched_clock can handle to be greater than 32. With more than 32 bits the wraparound time can be larger than what can fit into the units that msecs_to_jiffies takes (unsigned int). Luckily, the wraparound is initially calculated in nanoseconds which we can easily use with hrtimers, so switch to using an hrtimer. Change-Id: Id6059fae75863ddd3972f4dcac1cf7b803b09ac9 Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> [jstultz: Fixup hrtimer intitialization order issue] Signed-off-by: John Stultz <john.stultz@linaro.org> Git-commit: a08ca5d1089da03724f96fa0870c64968e66765b Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Signed-off-by: Ian Maund <imaund@codeaurora.org> sched_clock: Add support for >32 bit sched_clock The ARM architected system counter has at least 56 usable bits. Add support for counters with more than 32 bits to the generic sched_clock implementation so we can increase the time between wakeups due to dealing with wrap-around on these devices while benefiting from the irqtime accounting and suspend/resume handling that the generic sched_clock code already has. On my system using 56 bits over 32 bits changes the wraparound time from a few minutes to an hour. For faster running counters (GHz range) this is even more important because we may not be able to execute the timer in time to deal with the wraparound if only 32 bits are used. We choose a maxsec value of 3600 seconds because we assume no system will go idle for more than an hour. In the future we may need to increase this value. Note: All users should switch over to the 64-bit read function so we can remove setup_sched_clock() in favor of sched_clock_register(). Change-Id: I81a4b7102db5316bd31d1fa54e2d801f1ee133c1 Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Git-commit: e7e3ff1bfe9c42ee31172e9afdc0383a9e595e29 Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Signed-off-by: Ian Maund <imaund@codeaurora.org> sched_clock: Avoid corrupting hrtimer tree during suspend During suspend we call sched_clock_poll() to update the epoch and accumulated time and reprogram the sched_clock_timer to fire before the next wrap-around time. Unfortunately, sched_clock_poll() doesn't restart the timer, instead it relies on the hrtimer layer to do that and during suspend we aren't calling that function from the hrtimer layer. Instead, we're reprogramming the expires time while the hrtimer is enqueued, which can cause the hrtimer tree to be corrupted. Furthermore, we restart the timer during suspend but we update the epoch during resume which seems counter-intuitive. Let's fix this by saving the accumulated state and canceling the timer during suspend. On resume we can update the epoch and restart the timer similar to what we would do if we were starting the clock for the first time. Change-Id: Iee2a1cca42e5b681347ea0607e9af420a63892d7 CRs-Fixed: 696826 Fixes: a08ca5d1089d "sched_clock: Use an hrtimer instead of timer" Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> sched_clock: Make ARM's sched_clock generic for all architectures Nothing about the sched_clock implementation in the ARM port is specific to the architecture. Generalize the code so that other architectures can use it by selecting GENERIC_SCHED_CLOCK. Change-Id: I1e846fd1fb87ec1217ea84f1e2e02596c9eaa96b Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> [jstultz: Merge minor collisions with other patches in my tree] Signed-off-by: John Stultz <john.stultz@linaro.org> Change-Id: Id4ff982d3b5dfdc2fa172f3bdbddc6021134c932 Signed-off-by: Kevin F. Haggerty <haggertk@lineageos.org>