From mboxrd@z Thu Jan 1 00:00:00 1970 From: jeremy.linton@arm.com (Jeremy Linton) Date: Fri, 10 Mar 2017 16:14:57 -0600 Subject: [PATCH 00/14] arm_pmu: ACPI support In-Reply-To: <1489143891-11596-1-git-send-email-mark.rutland@arm.com> References: <1489143891-11596-1-git-send-email-mark.rutland@arm.com> Message-ID: <5b5dca5f-0ea3-d7e7-63c9-dba57969d4be@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On 03/10/2017 05:04 AM, Mark Rutland wrote: > Hi, > > This series implements ACPI support in the ARM PMU code. It borrows some code > from Jeremy's series [1], but takes a different approach to probing and > association, using the usual hotplug state machine, minimising external changes > required, and simplifying the relationship with the common arm_pmu code. > > The first few patches are preparatory cleanup/refactoring, with the latter half > of the series being specific to ACPI support. > > The series is based on my IRQ rework patches [2]. I've pushed the whole series > out to the arm/perf/acpi branch [3] of my kernel.org repo. > > Due to the innards of the hotplug callback framework, it's not entirely > safe to register a PMU in a hotplug callback. Due to this, we can only > associated hotplugged CPUs with a PMU if a matching CPU was around at > probe time. A similar restriction already applies to DT systems. We may > be able to relax this with some future work. Which is disappointing, as I thought that was one of Lorenzo's complaints about the last patch series. > > I've given this some testing on a Juno platform (using SPIs). To see that IRQs > are correctly associated, I've tested with the following: > > $ taskset -c ${SOME_CPU_HERE} perf record \ > -e armv8_pmuv3_0/cpu_cycles/ \ > -e armv8_pmuv3_1/cpu_cycles/ \ > cat /proc/interrupts > > I've also booted with nr_cpus temporarily capped (passing maxcpus=) to test the > association logic. This has also been tested in a VM using PPIs; I do not have > access to a host machine which itself uses PPIs. I tried these patches on a m400 (which uses PPIs), and the kernel fails to come up enough to login via the network (which works with 4.11rc1 without these patches). So, I suspect there is something wrong with them. Although its quite possibly PEBCAK. Given that SPCR/etc is also broken and the kernel itself seems to fail if I give it a full earlycon line, I can't pin down whats going on with the PMU code until I fix the console. About the only thing it says with any meaning when earlycon is passed is: [ 10.965147] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled [ 11.064193] dw-apb-uart APMC0D08:00: cannot get irq and promptly hangs up. I'm OOO for the next week, and will debug this further when I return if no one else makes any progress. > > Thanks, > Mark. > > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-January/482397.html > [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-March/492891.html > [3] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git arm/perf/acpi > > Mark Rutland (14): > drivers/perf: arm_pmu: remove pointless PMU disabling > drivers/perf: arm_pmu: define armpmu_init_fn > drivers/perf: arm_pmu: fold init into alloc > drivers/perf: arm_pmu: factor out pmu registration > drivers/perf: arm_pmu: simplify cpu_pmu_request_irqs() > drivers/perf: arm_pmu: handle no platform_device > drivers/perf: arm_pmu: rename irq request/free functions > drivers/perf: arm_pmu: split cpu-local irq request/free > drivers/perf: arm_pmu: move irq request/free into probe > drivers/perf: arm_pmu: split out platform device probe logic > arm64: add function to get a cpu's MADT GICC table > arm64: kill acpi_set_mailbox_entry() > drivers/perf: arm_pmu: add ACPI framework > arm64: pmuv3: use arm_pmu ACPI framework > > arch/arm64/include/asm/acpi.h | 7 +- > arch/arm64/kernel/acpi_parking_protocol.c | 38 +-- > arch/arm64/kernel/perf_event.c | 26 +- > arch/arm64/kernel/smp.c | 19 +- > drivers/perf/Kconfig | 4 + > drivers/perf/Makefile | 3 +- > drivers/perf/arm_pmu.c | 383 ++++++++---------------------- > drivers/perf/arm_pmu_acpi.c | 237 ++++++++++++++++++ > drivers/perf/arm_pmu_platform.c | 235 ++++++++++++++++++ > include/linux/cpuhotplug.h | 1 + > include/linux/perf/arm_pmu.h | 22 +- > 11 files changed, 626 insertions(+), 349 deletions(-) > create mode 100644 drivers/perf/arm_pmu_acpi.c > create mode 100644 drivers/perf/arm_pmu_platform.c >