From: Ulf Hansson <ulf.hansson@linaro.org>
To: Lina Iyer <ilina@codeaurora.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Linux PM <linux-pm@vger.kernel.org>,
Stephen Boyd <sboyd@kernel.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Kevin Hilman <khilman@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Tony Lindgren <tony@atomide.com>,
Sudeep Holla <sudeep.holla@arm.com>,
"Raju P.L.S.S.S.N" <rplsssn@codeaurora.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v10 24/27] drivers: firmware: psci: Support CPU hotplug for the hierarchical model
Date: Fri, 30 Nov 2018 09:25:14 +0100 [thread overview]
Message-ID: <CAPDyKFqUoYXUrj9N7f0DKxeL-BikwqKRWAB9FCX2PznkgiumcA@mail.gmail.com> (raw)
In-Reply-To: <20181129223130.GH18262@codeaurora.org>
On Thu, 29 Nov 2018 at 23:31, Lina Iyer <ilina@codeaurora.org> wrote:
>
> Hi Ulf,
>
> On Thu, Nov 29 2018 at 10:50 -0700, Ulf Hansson wrote:
> >When the hierarchical CPU topology is used and when a CPU has been put
> >offline (hotplug), that same CPU prevents its PM domain and thus also
> >potential master PM domains, from being powered off. This is because genpd
> >observes the CPU's struct device to remain being active from a runtime PM
> >point of view.
> >
> >To deal with this, let's decrease the runtime PM usage count by calling
> >pm_runtime_put_sync_suspend() of the CPU's struct device when putting it
> >offline. Consequentially, we must then increase the runtime PM usage for
> >the CPU, while putting it online again.
> >
> >Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> >---
> >
> >Changes in v10:
> > - Make it work when the hierarchical CPU topology is used, which may be
> > used both for OSI and PC mode.
> > - Rework the code to prevent "BUG: sleeping function called from
> > invalid context".
> >---
> > drivers/firmware/psci/psci.c | 20 ++++++++++++++++++++
> > 1 file changed, 20 insertions(+)
> >
> >diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> >index b03bccce0a5d..f62c4963eb62 100644
> >--- a/drivers/firmware/psci/psci.c
> >+++ b/drivers/firmware/psci/psci.c
> >@@ -15,6 +15,7 @@
> >
> > #include <linux/acpi.h>
> > #include <linux/arm-smccc.h>
> >+#include <linux/cpu.h>
> > #include <linux/cpuidle.h>
> > #include <linux/errno.h>
> > #include <linux/linkage.h>
> >@@ -199,9 +200,20 @@ static int psci_cpu_suspend(u32 state, unsigned long entry_point)
> >
> > static int psci_cpu_off(u32 state)
> > {
> >+ struct device *dev;
> > int err;
> > u32 fn;
> >
> >+ /*
> >+ * When the hierarchical CPU topology is used, decrease the runtime PM
> >+ * usage count for the current CPU, as to allow other parts in the
> >+ * topology to enter low power states.
> >+ */
> >+ if (psci_dt_topology) {
> >+ dev = get_cpu_device(smp_processor_id());
> >+ pm_runtime_put_sync_suspend(dev);
> >+ }
> >+
> > fn = psci_function_id[PSCI_FN_CPU_OFF];
> > err = invoke_psci_fn(fn, state, 0, 0);
> > return psci_to_linux_errno(err);
> >@@ -209,6 +221,7 @@ static int psci_cpu_off(u32 state)
> >
> > static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
> > {
> >+ struct device *dev;
> > int err;
> > u32 fn;
> >
> >@@ -216,6 +229,13 @@ static int psci_cpu_on(unsigned long cpuid, unsigned long entry_point)
> > err = invoke_psci_fn(fn, cpuid, entry_point, 0);
> > /* Clear the domain state to start fresh. */
> > psci_set_domain_state(0);
> >+
> >+ /* Increase runtime PM usage count if the hierarchical CPU toplogy. */
> >+ if (!err && psci_dt_topology) {
> >+ dev = get_cpu_device(cpuid);
> >+ pm_runtime_get_sync(dev);
>
> I booted with a single CPU on my SDM845 device and when I tried to
> online CPU1 and I see a crash.
Thanks for testing!
If I understand correctly, that means that you haven't registered CPU1
using register_cpu(), hence there are no struct device created for it.
It sound like a special case, but on the other hand we shouldn't
crash, or course.
I guess a simple check like this would help.
if (dev)
pm_runtime_get_sync(dev);
...and then we need a similar check in psci_cpu_off() to deal with
putting the CPU offline.
Could you try this and see if it helps?
>
> # echo 1 > /sys/devices/system/cpu/cpu1/online
>
> [ 86.339204] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000188
> [ 86.340195] Detected VIPT I-cache on CPU1
> [ 86.348075] Mem abort info:
> [ 86.348092] GICv3: CPU1: found redistributor 100 region 0:0x0000000017a80000
> [ 86.352125] ESR = 0x96000006
> [ 86.352194] CPU1: Booted secondary processor 0x0000000100 [0x517f803c]
> [ 86.354956] Exception class = DABT (current EL), IL = 32 bits
> [ 86.377700] SET = 0, FnV = 0
> [ 86.380788] EA = 0, S1PTW = 0
> [ 86.383967] Data abort info:
> [ 86.386882] ISV = 0, ISS = 0x00000006
> [ 86.390760] CM = 0, WnR = 0
> [ 86.393755] user pgtable: 4k pages, 48-bit VAs, pgdp = (____ptrval____)
> [ 86.400430] [0000000000000188] pgd=00000001f5233003, pud=00000001f5234003, pmd=0000000000000000
> [ 86.409203] Internal error: Oops: 96000006 [#1] PREEMPT SMP
> [ 86.414824] Modules linked in:
> [ 86.417915] CPU: 0 PID: 1533 Comm: sh Not tainted 4.20.0-rc3-30359-gff2e21952bd5 #782
> [ 86.425807] Hardware name: Qualcomm Technologies, Inc. SDM845 MTP (DT)
> [ 86.432387] pstate: 80400005 (Nzcv daif +PAN -UAO)
> [ 86.437233] pc : __pm_runtime_resume+0x20/0x74
> [ 86.441720] lr : psci_cpu_on+0x84/0x90
> [ 86.445498] sp : ffff00000db43a10
> [ 86.448842] x29: ffff00000db43a10 x28: ffff80017562b500
> [ 86.454200] x27: ffff000009159000 x26: 0000000000000055
> [ 86.459556] x25: 0000000000000000 x24: ffff0000092c4bc8
> [ 86.464913] x23: ffff000008fb8000 x22: ffff00000916a000
> [ 86.470269] x21: 0000000000000100 x20: ffff000009314190
> [ 86.475625] x19: 0000000000000000 x18: 0000000000000000
> [ 86.480979] x17: 0000000000000000 x16: 0000000000000000
> [ 86.486334] x15: 0000000000000000 x14: ffff000009162600
> [ 86.491690] x13: 0000000000000300 x12: 0000000000000010
> [ 86.497047] x11: ffffffffffffffff x10: ffffffffffffffff
> [ 86.502399] x9 : 0000000000000001 x8 : 0000000000000000
> [ 86.507753] x7 : 0000000000000000 x6 : 0000000000000000
> [ 86.513108] x5 : 0000000000000000 x4 : 0000000000000000
> [ 86.518463] x3 : 0000000000000188 x2 : 0000800174385000
> [ 86.523820] x1 : 0000000000000004 x0 : 0000000000000000
> [ 86.529175] Process sh (pid: 1533, stack limit = 0x(____ptrval____))
> [ 86.535585] Call trace:
> [ 86.538063] __pm_runtime_resume+0x20/0x74
> [ 86.542197] psci_cpu_on+0x84/0x90
> [ 86.545639] cpu_psci_cpu_boot+0x3c/0x6c
> [ 86.549593] __cpu_up+0x68/0x210
> [ 86.552852] bringup_cpu+0x30/0xe0
> [ 86.556293] cpuhp_invoke_callback+0x84/0x1e0
> [ 86.560689] _cpu_up+0xe0/0x1d0
> [ 86.563862] do_cpu_up+0x90/0xb0
> [ 86.567118] cpu_up+0x10/0x18
> [ 86.570113] cpu_subsys_online+0x44/0x98
> [ 86.574079] device_online+0x68/0xac
> [ 86.577685] online_store+0xa8/0xb4
> [ 86.581202] dev_attr_store+0x18/0x28
> [ 86.584908] sysfs_kf_write+0x40/0x48
> [ 86.588606] kernfs_fop_write+0xcc/0x1cc
> [ 86.592563] __vfs_write+0x40/0x16c
> [ 86.596078] vfs_write+0xa8/0x1a0
> [ 86.599424] ksys_write+0x58/0xbc
> [ 86.602768] __arm64_sys_write+0x18/0x20
> [ 86.606733] el0_svc_common+0x94/0xf0
> [ 86.610433] el0_svc_handler+0x24/0x80
> [ 86.614215] el0_svc+0x8/0x7c0
> [ 86.617300] Code: aa0003f3 361000e1 91062263 f9800071 (885f7c60)
> [ 86.623447] ---[ end trace 4573c3c0e0761290 ]---
>
> >+ }
> >+
> > return psci_to_linux_errno(err);
> > }
> >
> >--
> >2.17.1
> >
>
> Thanks,
> Lina
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next prev parent reply other threads:[~2018-11-30 8:26 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-29 17:46 [PATCH v10 00/27] PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 01/27] PM / Domains: Add generic data pointer to genpd_power_state struct Ulf Hansson
2018-12-18 10:39 ` Daniel Lezcano
2018-12-18 11:53 ` Ulf Hansson
2019-01-11 10:52 ` Rafael J. Wysocki
2018-11-29 17:46 ` [PATCH v10 02/27] PM / Domains: Add support for CPU devices to genpd Ulf Hansson
2018-12-19 9:53 ` Daniel Lezcano
2018-12-19 10:02 ` Ulf Hansson
2019-01-11 10:54 ` Rafael J. Wysocki
2018-11-29 17:46 ` [PATCH v10 03/27] timer: Export next wakeup time of a CPU Ulf Hansson
2019-01-11 11:06 ` Rafael J. Wysocki
2019-01-16 7:57 ` Ulf Hansson
2019-01-16 10:59 ` Rafael J. Wysocki
2019-01-16 12:00 ` Ulf Hansson
2019-01-25 10:04 ` Ulf Hansson
2019-01-25 10:18 ` Rafael J. Wysocki
2018-11-29 17:46 ` [PATCH v10 04/27] PM / Domains: Add genpd governor for CPUs Ulf Hansson
2018-12-19 9:54 ` Daniel Lezcano
2018-12-19 10:09 ` Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 05/27] dt: psci: Update DT bindings to support hierarchical PSCI states Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 06/27] of: base: Add of_get_cpu_state_node() to get idle states for a CPU node Ulf Hansson
2018-12-19 11:05 ` Daniel Lezcano
2018-11-29 17:46 ` [PATCH v10 07/27] cpuidle: dt: Support hierarchical CPU idle states Ulf Hansson
2018-12-19 11:20 ` Daniel Lezcano
2018-11-29 17:46 ` [PATCH v10 08/27] ARM/ARM64: cpuidle: Let back-end init ops take the driver as input Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 09/27] drivers: firmware: psci: Move psci to separate directory Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 10/27] MAINTAINERS: Update files for PSCI Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 11/27] drivers: firmware: psci: Split psci_dt_cpu_init_idle() Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 12/27] drivers: firmware: psci: Simplify state node parsing Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 13/27] drivers: firmware: psci: Support hierarchical CPU idle states Ulf Hansson
2018-12-19 12:11 ` Daniel Lezcano
2018-12-19 12:53 ` Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 14/27] drivers: firmware: psci: Simplify error path of psci_dt_init() Ulf Hansson
2018-12-19 12:08 ` Daniel Lezcano
2018-11-29 17:46 ` [PATCH v10 15/27] drivers: firmware: psci: Announce support for OS initiated suspend mode Ulf Hansson
2018-12-20 13:11 ` Daniel Lezcano
2018-11-29 17:46 ` [PATCH v10 16/27] drivers: firmware: psci: Prepare to use " Ulf Hansson
2018-12-20 14:08 ` Daniel Lezcano
2018-12-20 15:41 ` Ulf Hansson
2018-12-20 17:16 ` Daniel Lezcano
2018-11-29 17:46 ` [PATCH v10 17/27] drivers: firmware: psci: Prepare to support PM domains Ulf Hansson
2018-12-20 14:19 ` Daniel Lezcano
2018-12-20 15:49 ` Ulf Hansson
2018-12-20 18:06 ` Daniel Lezcano
2018-12-20 21:37 ` Ulf Hansson
2018-12-21 7:15 ` Daniel Lezcano
2018-11-29 17:46 ` [PATCH v10 18/27] drivers: firmware: psci: Add support for PM domains using genpd Ulf Hansson
2018-12-03 16:37 ` Lina Iyer
2018-12-03 20:03 ` Ulf Hansson
2018-12-20 14:35 ` Daniel Lezcano
2018-12-20 21:09 ` Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 19/27] drivers: firmware: psci: Add hierarchical domain idle states converter Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 20/27] drivers: firmware: psci: Introduce psci_dt_topology_init() Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 21/27] drivers: firmware: psci: Add a helper to attach a CPU to its PM domain Ulf Hansson
2018-12-04 18:45 ` Lina Iyer
2018-12-06 9:15 ` Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 22/27] drivers: firmware: psci: Attach the CPU's device " Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 23/27] drivers: firmware: psci: Manage runtime PM in the idle path for CPUs Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 24/27] drivers: firmware: psci: Support CPU hotplug for the hierarchical model Ulf Hansson
2018-11-29 22:31 ` Lina Iyer
2018-11-30 8:25 ` Ulf Hansson [this message]
2018-11-30 20:57 ` Lina Iyer
2018-12-19 11:17 ` Lorenzo Pieralisi
2018-12-19 11:47 ` Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 25/27] arm64: kernel: Respect the hierarchical CPU topology in DT for PSCI Ulf Hansson
2018-11-29 17:46 ` [PATCH v10 26/27] arm64: dts: Convert to the hierarchical CPU topology layout for MSM8916 Ulf Hansson
2018-11-29 17:47 ` [PATCH v10 27/27] arm64: dts: hikey: Convert to the hierarchical CPU topology layout Ulf Hansson
2018-12-17 16:12 ` [PATCH v10 00/27] PM / Domains: Support hierarchical CPU arrangement (PSCI/ARM) Ulf Hansson
2019-01-11 11:08 ` Rafael J. Wysocki
2019-01-03 12:06 ` Sudeep Holla
2019-01-16 9:10 ` Ulf Hansson
2019-01-17 17:44 ` Sudeep Holla
2019-01-18 11:56 ` Ulf Hansson
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