* [PATCH 0/2] couple of minor DAWR fixes
From: Nicholas Piggin @ 2018-04-01 5:50 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin
Nicholas Piggin (2):
KVM: PPC: Book3S HV: Fix ppc_breakpoint_available compile error
powerpc: Fix DABR write in the case of DAWR disabled
arch/powerpc/kernel/process.c | 13 +++++++++----
arch/powerpc/kvm/book3s_hv.c | 1 +
2 files changed, 10 insertions(+), 4 deletions(-)
--
2.16.3
^ permalink raw reply
* [PATCH 1/2] KVM: PPC: Book3S HV: Fix ppc_breakpoint_available compile error
From: Nicholas Piggin @ 2018-04-01 5:50 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Michael Neuling
In-Reply-To: <20180401055036.18078-1-npiggin@gmail.com>
arch/powerpc/kvm/book3s_hv.c: In function ‘kvmppc_h_set_mode’:
arch/powerpc/kvm/book3s_hv.c:745:8: error: implicit declaration of function ‘ppc_breakpoint_available’; did you mean ‘hw_breakpoint_disable’? [-Werror=implicit-function-declaration]
if (!ppc_breakpoint_available())
^~~~~~~~~~~~~~~~~~~~~~~~
hw_breakpoint_disable
Cc: Michael Neuling <mikey@neuling.org>
Fixes: 398e712c00 ("KVM: PPC: Book3S HV: Return error from h_set_mode(SET_DAWR) on POWER9")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kvm/book3s_hv.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 948642e16338..81e2ea882d97 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -49,6 +49,7 @@
#include <asm/reg.h>
#include <asm/ppc-opcode.h>
#include <asm/asm-prototypes.h>
+#include <asm/debug.h>
#include <asm/disassemble.h>
#include <asm/cputable.h>
#include <asm/cacheflush.h>
--
2.16.3
^ permalink raw reply related
* [PATCH 2/2] powerpc: Fix DABR write in the case of DAWR disabled
From: Nicholas Piggin @ 2018-04-01 5:50 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Michael Neuling
In-Reply-To: <20180401055036.18078-1-npiggin@gmail.com>
flush_thread will call set_breakpoint via set_debug_reg_defaults,
and cause POWER8 and above CPUs without the DAWR feature to try
to write to DAWR.
Cc: Michael Neuling <mikey@neuling.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/process.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 24a591b4dbe9..bfcf5437083c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -718,7 +718,8 @@ static void set_debug_reg_defaults(struct thread_struct *thread)
{
thread->hw_brk.address = 0;
thread->hw_brk.type = 0;
- set_breakpoint(&thread->hw_brk);
+ if (ppc_breakpoint_available())
+ set_breakpoint(&thread->hw_brk);
}
#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
@@ -814,10 +815,14 @@ void __set_breakpoint(struct arch_hw_breakpoint *brk)
{
memcpy(this_cpu_ptr(¤t_brk), brk, sizeof(*brk));
- if (cpu_has_feature(CPU_FTR_DAWR))
- set_dawr(brk);
- else
+ if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+ if (cpu_has_feature(CPU_FTR_DAWR))
+ set_dawr(brk);
+ else
+ WARN_ON_ONCE(1);
+ } else {
set_dabr(brk);
+ }
}
void set_breakpoint(struct arch_hw_breakpoint *brk)
--
2.16.3
^ permalink raw reply related
* Re: [PATCH 00/32] docs/vm: convert to ReST format
From: Mike Rapoport @ 2018-04-01 6:38 UTC (permalink / raw)
To: Jonathan Corbet, Andrew Morton
Cc: Andrey Ryabinin, Richard Henderson, Ivan Kokshaysky, Matt Turner,
Tony Luck, Fenghua Yu, Ralf Baechle, James Hogan,
Michael Ellerman, Alexander Viro, linux-kernel, linux-doc,
kasan-dev, linux-alpha, linux-ia64, linux-mips, linuxppc-dev,
linux-fsdevel, linux-mm
In-Reply-To: <20180329154607.3d8bda75@lwn.net>
(added akpm)
On Thu, Mar 29, 2018 at 03:46:07PM -0600, Jonathan Corbet wrote:
> On Wed, 21 Mar 2018 21:22:16 +0200
> Mike Rapoport <rppt@linux.vnet.ibm.com> wrote:
>
> > These patches convert files in Documentation/vm to ReST format, add an
> > initial index and link it to the top level documentation.
> >
> > There are no contents changes in the documentation, except few spelling
> > fixes. The relatively large diffstat stems from the indentation and
> > paragraph wrapping changes.
> >
> > I've tried to keep the formatting as consistent as possible, but I could
> > miss some places that needed markup and add some markup where it was not
> > necessary.
>
> So I've been pondering on these for a bit. It looks like a reasonable and
> straightforward RST conversion, no real complaints there. But I do have a
> couple of concerns...
>
> One is that, as we move documentation into RST, I'm really trying to
> organize it a bit so that it is better tuned to the various audiences we
> have. For example, ksm.txt is going to be of interest to sysadmin types,
> who might want to tune it. mmu_notifier.txt is of interest to ...
> somebody, but probably nobody who is thinking in user space. And so on.
>
> So I would really like to see this material split up and put into the
> appropriate places in the RST hierarchy - admin-guide for administrative
> stuff, core-api for kernel development topics, etc. That, of course,
> could be done separately from the RST conversion, but I suspect I know
> what will (or will not) happen if we agree to defer that for now :)
Well, I was actually planning on doing that ;-)
My thinking was to start with mechanical RST conversion and then to start
working on the contents and ordering of the documentation. Some of the
existing files, e.g. ksm.txt, can be moved as is into the appropriate
places, others, like transhuge.txt should be at least split into admin/user
and developer guides.
Another problem with many of the existing mm docs is that they are rather
developer notes and it wouldn't be really straight forward to assign them
to a particular topic.
I believe that keeping the mm docs together will give better visibility of
what (little) mm documentation we have and will make the updates easier.
The documents that fit well into a certain topic could be linked there. For
instance:
-------------------------
diff --git a/Documentation/admin-guide/index.rst b/Documentation/admin-guide/index.rst
index 5bb9161..8f6c6e6 100644
--- a/Documentation/admin-guide/index.rst
+++ b/Documentation/admin-guide/index.rst
@@ -63,6 +63,7 @@ configure specific aspects of kernel behavior to your liking.
pm/index
thunderbolt
LSM/index
+ vm/index
.. only:: subproject and html
diff --git a/Documentation/admin-guide/vm/index.rst b/Documentation/admin-guide/vm/index.rst
new file mode 100644
index 0000000..d86f1c8
--- /dev/null
+++ b/Documentation/admin-guide/vm/index.rst
@@ -0,0 +1,5 @@
+==============================================
+Knobs and Buttons for Memory Management Tuning
+==============================================
+
+* :ref:`ksm <ksm>`
-------------------------
> The other is the inevitable merge conflicts that changing that many doc
> files will create. Sending the patches through Andrew could minimize
> that, I guess, or at least make it his problem. Alternatively, we could
> try to do it as an end-of-merge-window sort of thing. I can try to manage
> that, but an ack or two from the mm crowd would be nice to have.
I can rebase on top of Andrew's tree if that would help to minimize the
merge conflicts.
> Thanks,
>
> jon
>
--
Sincerely yours,
Mike.
^ permalink raw reply related
* Re: [PATCH 2/2] powerpc: Fix DABR write in the case of DAWR disabled
From: Nicholas Piggin @ 2018-04-01 7:40 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Michael Neuling
In-Reply-To: <20180401055036.18078-3-npiggin@gmail.com>
On Sun, 1 Apr 2018 15:50:36 +1000
Nicholas Piggin <npiggin@gmail.com> wrote:
> flush_thread will call set_breakpoint via set_debug_reg_defaults,
> and cause POWER8 and above CPUs without the DAWR feature to try
> to write to DAWR.
^^^^
DABR
>
> Cc: Michael Neuling <mikey@neuling.org>
> Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
> ---
> arch/powerpc/kernel/process.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index 24a591b4dbe9..bfcf5437083c 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -718,7 +718,8 @@ static void set_debug_reg_defaults(struct thread_struct *thread)
> {
> thread->hw_brk.address = 0;
> thread->hw_brk.type = 0;
> - set_breakpoint(&thread->hw_brk);
> + if (ppc_breakpoint_available())
> + set_breakpoint(&thread->hw_brk);
> }
> #endif /* !CONFIG_HAVE_HW_BREAKPOINT */
> #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
> @@ -814,10 +815,14 @@ void __set_breakpoint(struct arch_hw_breakpoint *brk)
> {
> memcpy(this_cpu_ptr(¤t_brk), brk, sizeof(*brk));
>
> - if (cpu_has_feature(CPU_FTR_DAWR))
> - set_dawr(brk);
> - else
> + if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
> + if (cpu_has_feature(CPU_FTR_DAWR))
> + set_dawr(brk);
> + else
> + WARN_ON_ONCE(1);
> + } else {
> set_dabr(brk);
> + }
> }
>
> void set_breakpoint(struct arch_hw_breakpoint *brk)
^ permalink raw reply
* [PATCH 0/3] stop secondaries for reboot/shutdown
From: Nicholas Piggin @ 2018-04-01 10:36 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Vasant Hegde
I'm rebasing and resending this series because the hard
lockup messages are being seen in the field.
Since last time, one of the patches was merged, and patches
were split and reordered a bit. No major changes.
This still hasn't been tested with the FSP firmware update.
Thanks,
Nick
Nicholas Piggin (3):
powerpc: use NMI IPI for smp_send_stop
powerpc: hard disable irqs in smp_send_stop loop
powerpc/powernv: Always stop secondaries before reboot/shutdown
arch/powerpc/include/asm/opal.h | 2 +-
arch/powerpc/kernel/smp.c | 13 +++++++++++--
arch/powerpc/platforms/powernv/opal-flash.c | 28 +---------------------------
arch/powerpc/platforms/powernv/setup.c | 15 +++++----------
4 files changed, 18 insertions(+), 40 deletions(-)
--
2.16.3
^ permalink raw reply
* [PATCH v2 1/3] powerpc: use NMI IPI for smp_send_stop
From: Nicholas Piggin @ 2018-04-01 10:36 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Vasant Hegde
In-Reply-To: <20180401103615.15454-1-npiggin@gmail.com>
Use the NMI IPI rather than smp_call_function for smp_send_stop.
Have stopped CPUs hard disable interrupts rather than just soft
disable.
This function is used in crash/panic/shutdown paths to bring other
CPUs down as quickly and reliably as possible, and minimizing their
potential to cause trouble.
Avoiding the Linux smp_call_function infrastructure and (if supported)
using true NMI IPIs makes this more robust.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/smp.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index cfc08b099c49..db88660bf6bd 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -565,7 +565,11 @@ void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *))
}
#endif
+#ifdef CONFIG_NMI_IPI
+static void stop_this_cpu(struct pt_regs *regs)
+#else
static void stop_this_cpu(void *dummy)
+#endif
{
/* Remove this CPU */
set_cpu_online(smp_processor_id(), false);
@@ -577,7 +581,11 @@ static void stop_this_cpu(void *dummy)
void smp_send_stop(void)
{
+#ifdef CONFIG_NMI_IPI
+ smp_send_nmi_ipi(NMI_IPI_ALL_OTHERS, stop_this_cpu, 1000000);
+#else
smp_call_function(stop_this_cpu, NULL, 0);
+#endif
}
struct thread_info *current_set[NR_CPUS];
--
2.16.3
^ permalink raw reply related
* [PATCH v2 2/3] powerpc: hard disable irqs in smp_send_stop loop
From: Nicholas Piggin @ 2018-04-01 10:36 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Vasant Hegde
In-Reply-To: <20180401103615.15454-1-npiggin@gmail.com>
The hard lockup watchdog can fire under local_irq_disable
on platforms with irq soft masking.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/smp.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index db88660bf6bd..e16ec7b3b427 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -574,9 +574,10 @@ static void stop_this_cpu(void *dummy)
/* Remove this CPU */
set_cpu_online(smp_processor_id(), false);
- local_irq_disable();
+ hard_irq_disable();
+ spin_begin();
while (1)
- ;
+ spin_cpu_relax();
}
void smp_send_stop(void)
--
2.16.3
^ permalink raw reply related
* [PATCH v2 3/3] powerpc/powernv: Always stop secondaries before reboot/shutdown
From: Nicholas Piggin @ 2018-04-01 10:36 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Nicholas Piggin, Vasant Hegde
In-Reply-To: <20180401103615.15454-1-npiggin@gmail.com>
Currently powernv reboot and shutdown requests just leave secondaries
to do their own things. This is undesirable because they can trigger
any number of watchdogs while waiting for reboot, but also we don't
know what else they might be doing -- they might be causing trouble,
trampling memory, etc.
The opal scheduled flash update code already ran into watchdog problems
due to flashing taking a long time, and it was fixed with 2196c6f1ed
("powerpc/powernv: Return secondary CPUs to firmware before FW update"),
which returns secondaries to opal. It's been found that regular reboots
can take over 10 seconds, which can result in the hard lockup watchdog
firing,
reboot: Restarting system
[ 360.038896709,5] OPAL: Reboot request...
Watchdog CPU:0 Hard LOCKUP
Watchdog CPU:44 detected Hard LOCKUP other CPUS:16
Watchdog CPU:16 Hard LOCKUP
watchdog: BUG: soft lockup - CPU#16 stuck for 3s! [swapper/16:0]
This patch removes the special case for flash update, and calls
smp_send_stop in all cases before calling reboot/shutdown.
smp_send_stop could return CPUs to OPAL, the main reason not to is
that the request could come from a NMI that interrupts OPAL code,
so re-entry to OPAL can cause a number of problems. Putting
secondaries into simple spin loops improves the chances of a
successful reboot.
Cc: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/include/asm/opal.h | 2 +-
arch/powerpc/platforms/powernv/opal-flash.c | 28 +---------------------------
arch/powerpc/platforms/powernv/setup.c | 15 +++++----------
3 files changed, 7 insertions(+), 38 deletions(-)
diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index dde60089d0d4..7159e1a6a61a 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -325,7 +325,7 @@ struct rtc_time;
extern unsigned long opal_get_boot_time(void);
extern void opal_nvram_init(void);
extern void opal_flash_update_init(void);
-extern void opal_flash_term_callback(void);
+extern void opal_flash_update_print_message(void);
extern int opal_elog_init(void);
extern void opal_platform_dump_init(void);
extern void opal_sys_param_init(void);
diff --git a/arch/powerpc/platforms/powernv/opal-flash.c b/arch/powerpc/platforms/powernv/opal-flash.c
index 1cb0b895a236..b37015101bf6 100644
--- a/arch/powerpc/platforms/powernv/opal-flash.c
+++ b/arch/powerpc/platforms/powernv/opal-flash.c
@@ -303,26 +303,9 @@ static int opal_flash_update(int op)
return rc;
}
-/* Return CPUs to OPAL before starting FW update */
-static void flash_return_cpu(void *info)
-{
- int cpu = smp_processor_id();
-
- if (!cpu_online(cpu))
- return;
-
- /* Disable IRQ */
- hard_irq_disable();
-
- /* Return the CPU to OPAL */
- opal_return_cpu();
-}
-
/* This gets called just before system reboots */
-void opal_flash_term_callback(void)
+void opal_flash_update_print_message(void)
{
- struct cpumask mask;
-
if (update_flash_data.status != FLASH_IMG_READY)
return;
@@ -333,15 +316,6 @@ void opal_flash_term_callback(void)
/* Small delay to help getting the above message out */
msleep(500);
-
- /* Return secondary CPUs to firmware */
- cpumask_copy(&mask, cpu_online_mask);
- cpumask_clear_cpu(smp_processor_id(), &mask);
- if (!cpumask_empty(&mask))
- smp_call_function_many(&mask,
- flash_return_cpu, NULL, false);
- /* Hard disable interrupts */
- hard_irq_disable();
}
/*
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 5f963286232f..ef8c9ce53a61 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -201,17 +201,12 @@ static void pnv_prepare_going_down(void)
*/
opal_event_shutdown();
- /* Soft disable interrupts */
- local_irq_disable();
+ /* Print flash update message if one is scheduled. */
+ opal_flash_update_print_message();
- /*
- * Return secondary CPUs to firwmare if a flash update
- * is pending otherwise we will get all sort of error
- * messages about CPU being stuck etc.. This will also
- * have the side effect of hard disabling interrupts so
- * past this point, the kernel is effectively dead.
- */
- opal_flash_term_callback();
+ smp_send_stop();
+
+ hard_irq_disable();
}
static void __noreturn pnv_restart(char *cmd)
--
2.16.3
^ permalink raw reply related
* Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()
From: Yury Norov @ 2018-04-01 11:11 UTC (permalink / raw)
To: Will Deacon
Cc: Paul E. McKenney, Chris Metcalf, Christopher Lameter,
Russell King - ARM Linux, Mark Rutland, Steven Rostedt,
Mathieu Desnoyers, Catalin Marinas, Pekka Enberg, David Rientjes,
Joonsoo Kim, Andrew Morton, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, linux-arm-kernel, linuxppc-dev,
kvm-ppc, linux-mm, linux-kernel
In-Reply-To: <20180327102116.GA2464@arm.com>
On Tue, Mar 27, 2018 at 11:21:17AM +0100, Will Deacon wrote:
> On Sun, Mar 25, 2018 at 08:50:04PM +0300, Yury Norov wrote:
> > kick_all_cpus_sync() forces all CPUs to sync caches by sending broadcast IPI.
> > If CPU is in extended quiescent state (idle task or nohz_full userspace), this
> > work may be done at the exit of this state. Delaying synchronization helps to
> > save power if CPU is in idle state and decrease latency for real-time tasks.
> >
> > This patch introduces kick_active_cpus_sync() and uses it in mm/slab and arm64
> > code to delay syncronization.
> >
> > For task isolation (https://lkml.org/lkml/2017/11/3/589), IPI to the CPU running
> > isolated task would be fatal, as it breaks isolation. The approach with delaying
> > of synchronization work helps to maintain isolated state.
> >
> > I've tested it with test from task isolation series on ThunderX2 for more than
> > 10 hours (10k giga-ticks) without breaking isolation.
> >
> > Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> > ---
> > arch/arm64/kernel/insn.c | 2 +-
> > include/linux/smp.h | 2 ++
> > kernel/smp.c | 24 ++++++++++++++++++++++++
> > mm/slab.c | 2 +-
> > 4 files changed, 28 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
> > index 2718a77da165..9d7c492e920e 100644
> > --- a/arch/arm64/kernel/insn.c
> > +++ b/arch/arm64/kernel/insn.c
> > @@ -291,7 +291,7 @@ int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)
> > * synchronization.
> > */
> > ret = aarch64_insn_patch_text_nosync(addrs[0], insns[0]);
> > - kick_all_cpus_sync();
> > + kick_active_cpus_sync();
> > return ret;
> > }
> > }
>
> I think this means that runtime modifications to the kernel text might not
> be picked up by CPUs coming out of idle. Shouldn't we add an ISB on that
> path to avoid executing stale instructions?
>
> Will
commit 153ae9d5667e7baab4d48c48e8ec30fbcbd86f1e
Author: Yury Norov <ynorov@caviumnetworks.com>
Date: Sat Mar 31 15:05:23 2018 +0300
Hi Will, Paul,
On my system there are 3 paths that go thru rcu_dynticks_eqs_exit(),
and so require isb().
First path starts at gic_handle_irq() on secondary_start_kernel stack.
gic_handle_irq() already issues isb(), and so we can do nothing.
Second path starts at el0_svc entry; and third path is the exit from
do_idle() on secondary_start_kernel stack.
For do_idle() path there is arch_cpu_idle_exit() hook that is not used by
arm64 at now, so I picked it. And for el0_svc, I've introduced isb_if_eqs
macro and call it at the beginning of el0_svc_naked.
I've tested it on ThunderX2 machine, and it works for me.
Below is my call traces and patch for them. If you OK with it, I think I'm
ready to submit v2 (but maybe split this patch for better readability).
Yury
[ 585.412095] Call trace:
[ 585.412097] [<fffffc00080878d8>] dump_backtrace+0x0/0x380
[ 585.412099] [<fffffc0008087c6c>] show_stack+0x14/0x20
[ 585.412101] [<fffffc0008a091ec>] dump_stack+0x98/0xbc
[ 585.412104] [<fffffc0008122080>] rcu_dynticks_eqs_exit+0x68/0x70
[ 585.412105] [<fffffc00081260f0>] rcu_irq_enter+0x48/0x50
[ 585.412106] [<fffffc00080c92c4>] irq_enter+0xc/0x70
[ 585.412108] [<fffffc0008113a64>] __handle_domain_irq+0x3c/0x120
[ 585.412109] [<fffffc00080816c4>] gic_handle_irq+0xc4/0x180
[ 585.412110] Exception stack(0xfffffc001130fe20 to 0xfffffc001130ff60)
[ 585.412112] fe20: 00000000000000a0 0000000000000000 0000000000000001 0000000000000000
[ 585.412113] fe40: 0000028f6f0b0000 0000000000000020 0013cd6f53963b31 0000000000000000
[ 585.412144] fe60: 0000000000000002 fffffc001130fed0 0000000000000b80 0000000000003400
[ 585.412146] fe80: 0000000000000000 0000000000000001 0000000000000000 00000000000001db
[ 585.412147] fea0: fffffc0008247a78 000003ff86dc61f8 0000000000000014 fffffc0008fc0000
[ 585.412149] fec0: fffffc00090143e8 fffffc0009014000 fffffc0008fc94a0 0000000000000000
[ 585.412150] fee0: 0000000000000000 fffffe8f46bb1700 0000000000000000 0000000000000000
[ 585.412152] ff00: 0000000000000000 fffffc001130ff60 fffffc0008085034 fffffc001130ff60
[ 585.412153] ff20: fffffc0008085038 0000000000400149 fffffc0009014000 fffffc0008fc94a0
[ 585.412155] ff40: ffffffffffffffff 0000000000000000 fffffc001130ff60 fffffc0008085038
[ 585.412156] [<fffffc0008082fb0>] el1_irq+0xb0/0x124
[ 585.412158] [<fffffc0008085038>] arch_cpu_idle+0x10/0x18
[ 585.412159] [<fffffc00080ff38c>] do_idle+0x10c/0x1d8
[ 585.412160] [<fffffc00080ff5ec>] cpu_startup_entry+0x24/0x28
[ 585.412162] [<fffffc000808db04>] secondary_start_kernel+0x15c/0x1a0
[ 585.412164] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0-isolation-160735-g59b71c1-dirty #18
[ 585.412058] Call trace:
[ 585.412060] [<fffffc00080878d8>] dump_backtrace+0x0/0x380
[ 585.412062] [<fffffc0008087c6c>] show_stack+0x14/0x20
[ 585.412064] [<fffffc0008a091ec>] dump_stack+0x98/0xbc
[ 585.412066] [<fffffc0008122080>] rcu_dynticks_eqs_exit+0x68/0x70
[ 585.412068] [<fffffc00081232bc>] rcu_eqs_exit.isra.23+0x64/0x80
[ 585.412069] [<fffffc000812609c>] rcu_user_exit+0xc/0x18
[ 585.412071] [<fffffc000817c34c>] __context_tracking_exit.part.2+0x74/0x98
[ 585.412072] [<fffffc000817c3e0>] context_tracking_exit.part.3+0x40/0x50
[ 585.412074] [<fffffc000817c4e0>] context_tracking_user_exit+0x30/0x38
[ 585.412075] Exception stack(0xfffffc00385afec0 to 0xfffffc00385b0000)
[ 585.412076] fec0: 00000000000000b1 000002aacd702420 0000000000000200 00000000000001f4
[ 585.412078] fee0: 0000000000000000 0000000000000008 000002aabec9af17 ffffffffffffffff
[ 585.412079] ff00: 0000000000000016 ffffffffffffffff 000003ffe7619470 0000000000000057
[ 585.412081] ff20: a3d70a3d70a3d70b 000000000000016d 2ce33e6c02ce33e7 00000000000001db
[ 585.412082] ff40: 000002aabec7d260 000003ff86dc61f8 0000000000000014 00000000000001f4
[ 585.412083] ff60: 0000000000000000 000002aabecab000 000002aacd6e2830 0000000000000001
[ 585.412085] ff80: 000002aacd6e2830 000002aabec58380 0000000000000054 000002aabebccf50
[ 585.412086] ffa0: 0000000000000054 000003ffe7619540 000002aabebcf538 000003ffe7619540
[ 585.412088] ffc0: 000003ff86dc6410 0000000060000000 00000000000000b1 0000000000000016
[ 585.412089] ffe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 585.412091] [<fffffc0008083498>] el0_svc_naked+0xc/0x3c
[ 585.446067] CPU: 68 PID: 0 Comm: swapper/68 Not tainted 4.14.0-isolation-160735-g59b71c1-dirty #18
[ 585.412038] Call trace:
[ 585.412041] [<fffffc00080878d8>] dump_backtrace+0x0/0x380
[ 585.412042] [<fffffc0008087c6c>] show_stack+0x14/0x20
[ 585.412045] [<fffffc0008a091ec>] dump_stack+0x98/0xbc
[ 585.412047] [<fffffc0008122080>] rcu_dynticks_eqs_exit+0x68/0x70
[ 585.412049] [<fffffc00081232bc>] rcu_eqs_exit.isra.23+0x64/0x80
[ 585.412050] [<fffffc0008126080>] rcu_idle_exit+0x18/0x28
[ 585.412052] [<fffffc00080ff398>] do_idle+0x118/0x1d8
[ 585.412053] [<fffffc00080ff5ec>] cpu_startup_entry+0x24/0x28
[ 585.412055] [<fffffc000808db04>] secondary_start_kernel+0x15c/0x1a0
[ 585.412057] CPU: 22 PID: 4315 Comm: nginx Not tainted 4.14.0-isolation-160735-g59b71c1-dirty #18
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
index e1c59d4008a8..efa5060a2f1c 100644
--- a/arch/arm64/kernel/entry.S
+++ b/arch/arm64/kernel/entry.S
@@ -35,22 +35,29 @@
#include <asm/unistd.h>
/*
- * Context tracking subsystem. Used to instrument transitions
- * between user and kernel mode.
+ * Save/restore needed during syscalls. Restore syscall arguments from
+ * the values already saved on stack during kernel_entry.
*/
- .macro ct_user_exit, syscall = 0
-#ifdef CONFIG_CONTEXT_TRACKING
- bl context_tracking_user_exit
- .if \syscall == 1
- /*
- * Save/restore needed during syscalls. Restore syscall arguments from
- * the values already saved on stack during kernel_entry.
- */
+ .macro __restore_syscall_args
ldp x0, x1, [sp]
ldp x2, x3, [sp, #S_X2]
ldp x4, x5, [sp, #S_X4]
ldp x6, x7, [sp, #S_X6]
- .endif
+ .endm
+
+ .macro el0_svc_restore_syscall_args
+#if !defined(CONFIG_TINY_RCU) || defined(CONFIG_CONTEXT_TRACKING)
+ __restore_syscall_args
+#endif
+ .endm
+
+/*
+ * Context tracking subsystem. Used to instrument transitions
+ * between user and kernel mode.
+ */
+ .macro ct_user_exit
+#ifdef CONFIG_CONTEXT_TRACKING
+ bl context_tracking_user_exit
#endif
.endm
@@ -433,6 +440,20 @@ __bad_stack:
ASM_BUG()
.endm
+/*
+ * Flush I-cache if CPU is in extended quiescent state
+ */
+ .macro isb_if_eqs
+#ifndef CONFIG_TINY_RCU
+ bl rcu_is_watching
+ tst w0, #0xff
+ b.ne 1f
+ /* Pairs with aarch64_insn_patch_text for EQS CPUs. */
+ isb
+1:
+#endif
+ .endm
+
el0_sync_invalid:
inv_entry 0, BAD_SYNC
ENDPROC(el0_sync_invalid)
@@ -840,8 +861,10 @@ el0_svc:
mov wsc_nr, #__NR_syscalls
el0_svc_naked: // compat entry point
stp x0, xscno, [sp, #S_ORIG_X0] // save the original x0 and syscall number
+ isb_if_eqs
enable_dbg_and_irq
- ct_user_exit 1
+ ct_user_exit
+ el0_svc_restore_syscall_args
ldr x16, [tsk, #TSK_TI_FLAGS] // check for syscall hooks
tst x16, #_TIF_SYSCALL_WORK
@@ -874,10 +897,7 @@ __sys_trace:
mov x1, sp // pointer to regs
cmp wscno, wsc_nr // check upper syscall limit
b.hs __ni_sys_trace
- ldp x0, x1, [sp] // restore the syscall args
- ldp x2, x3, [sp, #S_X2]
- ldp x4, x5, [sp, #S_X4]
- ldp x6, x7, [sp, #S_X6]
+ __restore_syscall_args
ldr x16, [stbl, xscno, lsl #3] // address in the syscall table
blr x16 // call sys_* routine
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 2dc0f8482210..f11afd2aa33a 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -88,6 +88,12 @@ void arch_cpu_idle(void)
trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
}
+void arch_cpu_idle_exit(void)
+{
+ if (!rcu_is_watching())
+ isb();
+}
+
#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
^ permalink raw reply related
* Re: [PATCH 2/2] smp: introduce kick_active_cpus_sync()
From: Paul E. McKenney @ 2018-04-01 14:10 UTC (permalink / raw)
To: Yury Norov
Cc: Will Deacon, Chris Metcalf, Christopher Lameter,
Russell King - ARM Linux, Mark Rutland, Steven Rostedt,
Mathieu Desnoyers, Catalin Marinas, Pekka Enberg, David Rientjes,
Joonsoo Kim, Andrew Morton, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, linux-arm-kernel, linuxppc-dev,
kvm-ppc, linux-mm, linux-kernel
In-Reply-To: <20180401111108.mudkiewzn33sifvk@yury-thinkpad>
On Sun, Apr 01, 2018 at 02:11:08PM +0300, Yury Norov wrote:
> On Tue, Mar 27, 2018 at 11:21:17AM +0100, Will Deacon wrote:
> > On Sun, Mar 25, 2018 at 08:50:04PM +0300, Yury Norov wrote:
> > > kick_all_cpus_sync() forces all CPUs to sync caches by sending broadcast IPI.
> > > If CPU is in extended quiescent state (idle task or nohz_full userspace), this
> > > work may be done at the exit of this state. Delaying synchronization helps to
> > > save power if CPU is in idle state and decrease latency for real-time tasks.
> > >
> > > This patch introduces kick_active_cpus_sync() and uses it in mm/slab and arm64
> > > code to delay syncronization.
> > >
> > > For task isolation (https://lkml.org/lkml/2017/11/3/589), IPI to the CPU running
> > > isolated task would be fatal, as it breaks isolation. The approach with delaying
> > > of synchronization work helps to maintain isolated state.
> > >
> > > I've tested it with test from task isolation series on ThunderX2 for more than
> > > 10 hours (10k giga-ticks) without breaking isolation.
> > >
> > > Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
> > > ---
> > > arch/arm64/kernel/insn.c | 2 +-
> > > include/linux/smp.h | 2 ++
> > > kernel/smp.c | 24 ++++++++++++++++++++++++
> > > mm/slab.c | 2 +-
> > > 4 files changed, 28 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
> > > index 2718a77da165..9d7c492e920e 100644
> > > --- a/arch/arm64/kernel/insn.c
> > > +++ b/arch/arm64/kernel/insn.c
> > > @@ -291,7 +291,7 @@ int __kprobes aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt)
> > > * synchronization.
> > > */
> > > ret = aarch64_insn_patch_text_nosync(addrs[0], insns[0]);
> > > - kick_all_cpus_sync();
> > > + kick_active_cpus_sync();
> > > return ret;
> > > }
> > > }
> >
> > I think this means that runtime modifications to the kernel text might not
> > be picked up by CPUs coming out of idle. Shouldn't we add an ISB on that
> > path to avoid executing stale instructions?
> >
> > Will
>
> commit 153ae9d5667e7baab4d48c48e8ec30fbcbd86f1e
> Author: Yury Norov <ynorov@caviumnetworks.com>
> Date: Sat Mar 31 15:05:23 2018 +0300
>
> Hi Will, Paul,
>
> On my system there are 3 paths that go thru rcu_dynticks_eqs_exit(),
> and so require isb().
>
> First path starts at gic_handle_irq() on secondary_start_kernel stack.
> gic_handle_irq() already issues isb(), and so we can do nothing.
>
> Second path starts at el0_svc entry; and third path is the exit from
> do_idle() on secondary_start_kernel stack.
>
> For do_idle() path there is arch_cpu_idle_exit() hook that is not used by
> arm64 at now, so I picked it. And for el0_svc, I've introduced isb_if_eqs
> macro and call it at the beginning of el0_svc_naked.
>
> I've tested it on ThunderX2 machine, and it works for me.
>
> Below is my call traces and patch for them. If you OK with it, I think I'm
> ready to submit v2 (but maybe split this patch for better readability).
I must defer to Will on this one.
Thanx, Paul
> Yury
>
> [ 585.412095] Call trace:
> [ 585.412097] [<fffffc00080878d8>] dump_backtrace+0x0/0x380
> [ 585.412099] [<fffffc0008087c6c>] show_stack+0x14/0x20
> [ 585.412101] [<fffffc0008a091ec>] dump_stack+0x98/0xbc
> [ 585.412104] [<fffffc0008122080>] rcu_dynticks_eqs_exit+0x68/0x70
> [ 585.412105] [<fffffc00081260f0>] rcu_irq_enter+0x48/0x50
> [ 585.412106] [<fffffc00080c92c4>] irq_enter+0xc/0x70
> [ 585.412108] [<fffffc0008113a64>] __handle_domain_irq+0x3c/0x120
> [ 585.412109] [<fffffc00080816c4>] gic_handle_irq+0xc4/0x180
> [ 585.412110] Exception stack(0xfffffc001130fe20 to 0xfffffc001130ff60)
> [ 585.412112] fe20: 00000000000000a0 0000000000000000 0000000000000001 0000000000000000
> [ 585.412113] fe40: 0000028f6f0b0000 0000000000000020 0013cd6f53963b31 0000000000000000
> [ 585.412144] fe60: 0000000000000002 fffffc001130fed0 0000000000000b80 0000000000003400
> [ 585.412146] fe80: 0000000000000000 0000000000000001 0000000000000000 00000000000001db
> [ 585.412147] fea0: fffffc0008247a78 000003ff86dc61f8 0000000000000014 fffffc0008fc0000
> [ 585.412149] fec0: fffffc00090143e8 fffffc0009014000 fffffc0008fc94a0 0000000000000000
> [ 585.412150] fee0: 0000000000000000 fffffe8f46bb1700 0000000000000000 0000000000000000
> [ 585.412152] ff00: 0000000000000000 fffffc001130ff60 fffffc0008085034 fffffc001130ff60
> [ 585.412153] ff20: fffffc0008085038 0000000000400149 fffffc0009014000 fffffc0008fc94a0
> [ 585.412155] ff40: ffffffffffffffff 0000000000000000 fffffc001130ff60 fffffc0008085038
> [ 585.412156] [<fffffc0008082fb0>] el1_irq+0xb0/0x124
> [ 585.412158] [<fffffc0008085038>] arch_cpu_idle+0x10/0x18
> [ 585.412159] [<fffffc00080ff38c>] do_idle+0x10c/0x1d8
> [ 585.412160] [<fffffc00080ff5ec>] cpu_startup_entry+0x24/0x28
> [ 585.412162] [<fffffc000808db04>] secondary_start_kernel+0x15c/0x1a0
> [ 585.412164] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0-isolation-160735-g59b71c1-dirty #18
>
> [ 585.412058] Call trace:
> [ 585.412060] [<fffffc00080878d8>] dump_backtrace+0x0/0x380
> [ 585.412062] [<fffffc0008087c6c>] show_stack+0x14/0x20
> [ 585.412064] [<fffffc0008a091ec>] dump_stack+0x98/0xbc
> [ 585.412066] [<fffffc0008122080>] rcu_dynticks_eqs_exit+0x68/0x70
> [ 585.412068] [<fffffc00081232bc>] rcu_eqs_exit.isra.23+0x64/0x80
> [ 585.412069] [<fffffc000812609c>] rcu_user_exit+0xc/0x18
> [ 585.412071] [<fffffc000817c34c>] __context_tracking_exit.part.2+0x74/0x98
> [ 585.412072] [<fffffc000817c3e0>] context_tracking_exit.part.3+0x40/0x50
> [ 585.412074] [<fffffc000817c4e0>] context_tracking_user_exit+0x30/0x38
> [ 585.412075] Exception stack(0xfffffc00385afec0 to 0xfffffc00385b0000)
> [ 585.412076] fec0: 00000000000000b1 000002aacd702420 0000000000000200 00000000000001f4
> [ 585.412078] fee0: 0000000000000000 0000000000000008 000002aabec9af17 ffffffffffffffff
> [ 585.412079] ff00: 0000000000000016 ffffffffffffffff 000003ffe7619470 0000000000000057
> [ 585.412081] ff20: a3d70a3d70a3d70b 000000000000016d 2ce33e6c02ce33e7 00000000000001db
> [ 585.412082] ff40: 000002aabec7d260 000003ff86dc61f8 0000000000000014 00000000000001f4
> [ 585.412083] ff60: 0000000000000000 000002aabecab000 000002aacd6e2830 0000000000000001
> [ 585.412085] ff80: 000002aacd6e2830 000002aabec58380 0000000000000054 000002aabebccf50
> [ 585.412086] ffa0: 0000000000000054 000003ffe7619540 000002aabebcf538 000003ffe7619540
> [ 585.412088] ffc0: 000003ff86dc6410 0000000060000000 00000000000000b1 0000000000000016
> [ 585.412089] ffe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
> [ 585.412091] [<fffffc0008083498>] el0_svc_naked+0xc/0x3c
> [ 585.446067] CPU: 68 PID: 0 Comm: swapper/68 Not tainted 4.14.0-isolation-160735-g59b71c1-dirty #18
>
> [ 585.412038] Call trace:
> [ 585.412041] [<fffffc00080878d8>] dump_backtrace+0x0/0x380
> [ 585.412042] [<fffffc0008087c6c>] show_stack+0x14/0x20
> [ 585.412045] [<fffffc0008a091ec>] dump_stack+0x98/0xbc
> [ 585.412047] [<fffffc0008122080>] rcu_dynticks_eqs_exit+0x68/0x70
> [ 585.412049] [<fffffc00081232bc>] rcu_eqs_exit.isra.23+0x64/0x80
> [ 585.412050] [<fffffc0008126080>] rcu_idle_exit+0x18/0x28
> [ 585.412052] [<fffffc00080ff398>] do_idle+0x118/0x1d8
> [ 585.412053] [<fffffc00080ff5ec>] cpu_startup_entry+0x24/0x28
> [ 585.412055] [<fffffc000808db04>] secondary_start_kernel+0x15c/0x1a0
> [ 585.412057] CPU: 22 PID: 4315 Comm: nginx Not tainted 4.14.0-isolation-160735-g59b71c1-dirty #18
>
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index e1c59d4008a8..efa5060a2f1c 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -35,22 +35,29 @@
> #include <asm/unistd.h>
>
> /*
> - * Context tracking subsystem. Used to instrument transitions
> - * between user and kernel mode.
> + * Save/restore needed during syscalls. Restore syscall arguments from
> + * the values already saved on stack during kernel_entry.
> */
> - .macro ct_user_exit, syscall = 0
> -#ifdef CONFIG_CONTEXT_TRACKING
> - bl context_tracking_user_exit
> - .if \syscall == 1
> - /*
> - * Save/restore needed during syscalls. Restore syscall arguments from
> - * the values already saved on stack during kernel_entry.
> - */
> + .macro __restore_syscall_args
> ldp x0, x1, [sp]
> ldp x2, x3, [sp, #S_X2]
> ldp x4, x5, [sp, #S_X4]
> ldp x6, x7, [sp, #S_X6]
> - .endif
> + .endm
> +
> + .macro el0_svc_restore_syscall_args
> +#if !defined(CONFIG_TINY_RCU) || defined(CONFIG_CONTEXT_TRACKING)
> + __restore_syscall_args
> +#endif
> + .endm
> +
> +/*
> + * Context tracking subsystem. Used to instrument transitions
> + * between user and kernel mode.
> + */
> + .macro ct_user_exit
> +#ifdef CONFIG_CONTEXT_TRACKING
> + bl context_tracking_user_exit
> #endif
> .endm
>
> @@ -433,6 +440,20 @@ __bad_stack:
> ASM_BUG()
> .endm
>
> +/*
> + * Flush I-cache if CPU is in extended quiescent state
> + */
> + .macro isb_if_eqs
> +#ifndef CONFIG_TINY_RCU
> + bl rcu_is_watching
> + tst w0, #0xff
> + b.ne 1f
> + /* Pairs with aarch64_insn_patch_text for EQS CPUs. */
> + isb
> +1:
> +#endif
> + .endm
> +
> el0_sync_invalid:
> inv_entry 0, BAD_SYNC
> ENDPROC(el0_sync_invalid)
> @@ -840,8 +861,10 @@ el0_svc:
> mov wsc_nr, #__NR_syscalls
> el0_svc_naked: // compat entry point
> stp x0, xscno, [sp, #S_ORIG_X0] // save the original x0 and syscall number
> + isb_if_eqs
> enable_dbg_and_irq
> - ct_user_exit 1
> + ct_user_exit
> + el0_svc_restore_syscall_args
>
> ldr x16, [tsk, #TSK_TI_FLAGS] // check for syscall hooks
> tst x16, #_TIF_SYSCALL_WORK
> @@ -874,10 +897,7 @@ __sys_trace:
> mov x1, sp // pointer to regs
> cmp wscno, wsc_nr // check upper syscall limit
> b.hs __ni_sys_trace
> - ldp x0, x1, [sp] // restore the syscall args
> - ldp x2, x3, [sp, #S_X2]
> - ldp x4, x5, [sp, #S_X4]
> - ldp x6, x7, [sp, #S_X6]
> + __restore_syscall_args
> ldr x16, [stbl, xscno, lsl #3] // address in the syscall table
> blr x16 // call sys_* routine
>
> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
> index 2dc0f8482210..f11afd2aa33a 100644
> --- a/arch/arm64/kernel/process.c
> +++ b/arch/arm64/kernel/process.c
> @@ -88,6 +88,12 @@ void arch_cpu_idle(void)
> trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
> }
>
> +void arch_cpu_idle_exit(void)
> +{
> + if (!rcu_is_watching())
> + isb();
> +}
> +
> #ifdef CONFIG_HOTPLUG_CPU
> void arch_cpu_idle_dead(void)
> {
>
^ permalink raw reply
* [PATCH v6 14/16] powerpc: Switch to generic free_initrd_mem.
From: Shea Levy @ 2018-04-01 14:59 UTC (permalink / raw)
To: linux-riscv, linux-kernel
Cc: Shea Levy, Benjamin Herrenschmidt, Paul Mackerras,
Michael Ellerman, linuxppc-dev
In-Reply-To: <20180401145931.7932-1-shea@shealevy.com>
The first patch in this series added a weakly-defined generic
implementation, which is functionally identical to the
architecture-specific one removed here.
Series boot-tested on RISC-V (which now uses the generic
implementation) and x86_64 (which doesn't).
Signed-off-by: Shea Levy <shea@shealevy.com>
---
arch/powerpc/mm/mem.c | 7 -------
1 file changed, 7 deletions(-)
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index fe8c61149fb8..e85b2a3cd264 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -404,13 +404,6 @@ void free_initmem(void)
free_initmem_default(POISON_FREE_INITMEM);
}
-#ifdef CONFIG_BLK_DEV_INITRD
-void __init free_initrd_mem(unsigned long start, unsigned long end)
-{
- free_reserved_area((void *)start, (void *)end, -1, "initrd");
-}
-#endif
-
/*
* This is called when a page has been modified by the kernel.
* It just marks the page as not i-cache clean. We do the i-cache
--
2.16.2
^ permalink raw reply related
* Re: [PATCH v4 14/16] powerpc: Use generic free_initrd_mem.
From: Shea Levy @ 2018-04-01 15:01 UTC (permalink / raw)
To: Michael Ellerman, Joe Perches, linux-riscv, linux-kernel
Cc: Benjamin Herrenschmidt, Paul Mackerras, Michal Hocko,
Vlastimil Babka, Andrew Morton, Dan Williams, Christophe Leroy,
Oliver O'Halloran, linuxppc-dev
In-Reply-To: <87a7ur10k3.fsf@concordia.ellerman.id.au>
[-- Attachment #1: Type: text/plain, Size: 1085 bytes --]
Hi Michael,
Michael Ellerman <mpe@ellerman.id.au> writes:
> Shea Levy <shea@shealevy.com> writes:
>
>> Joe Perches <joe@perches.com> writes:
>>
>>> On Wed, 2018-03-28 at 16:36 -0400, Shea Levy wrote:
>>>> Signed-off-by: Shea Levy <shea@shealevy.com>
>>>
>>> Most people seem to want some form of commit message
>>> and not just your sign-off.
>>>
>>
>> Ah, if the subject is insufficient I can add some more detail.
>
> Yeah please do.
>
> Seeing this patch in isolation, with no change log, I might think it's
> safe for me to just apply it.
>
> But that would break the build because I don't have patch 1.
>
> So for starters you need to explain that part, eg something like:
>
> A previous patch in the series added a weak definition of
> free_initrd_mem() in init/initramfs.c.
>
> The powerpc implementation is identical, so it can be removed allowing
> the generic version to be used.
>
>
> Then you could also tell me if you did/didn't build/boot test it.
Thanks for the feedback, can you let me know if the recently posted v6
fits the bill?
>
> cheers
Thanks,
Shea
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^ permalink raw reply
* Re: [PATCH] Extract initrd free logic from arch-specific code.
From: Shea Levy @ 2018-04-01 15:05 UTC (permalink / raw)
To: Ingo Molnar
Cc: linux-riscv, linux-kernel, Christoph Hellwig, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Mark Salter, Aurelien Jacquiot,
Mikael Starvik, Jesper Nilsson, Yoshinori Sato, Richard Kuo,
Tony Luck, Fenghua Yu, Geert Uytterhoeven, James Hogan,
Michal Simek, Ralf Baechle, David Howells, Ley Foon Tan,
Jonas Bonn, Stefan Kristiansson, Stafford Horne,
James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, Palmer Dabbelt, Albert Ou,
Martin Schwidefsky, Heiko Carstens, Chen Liqin, Lennox Wu,
Rich Felker, David S. Miller, Jeff Dike, Richard Weinberger,
Guan Xuetao, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86,
Chris Zankel, Max Filippov, Kate Stewart, Greg Kroah-Hartman,
Philippe Ombredanne, Eugeniy Paltsev, Al Viro, Vladimir Murzin,
Linus Walleij, Michal Hocko, Andrew Morton, Sudip Mukherjee,
Marc Zyngier, Rob Herring, Kees Cook, Vlastimil Babka,
Balbir Singh, Christophe Leroy, Joe Perches,
Oliver O'Halloran, Dan Williams, Wei Yang,
Christian König, Arnd Bergmann, Deepa Dinamani,
Daniel Thompson, Rob Landley, Florian Fainelli, linux-alpha,
linux-snps-arc, linux-arm-kernel, adi-buildroot-devel,
linux-c6x-dev, linux-cris-kernel, uclinux-h8-devel, linux-hexagon,
linux-ia64, linux-m68k, linux-metag, linux-mips, linux-am33-list,
nios2-dev, openrisc, linux-parisc, linuxppc-dev, linux-s390,
linux-sh, sparclinux, user-mode-linux-devel, user-mode-linux-user,
linux-xtensa
In-Reply-To: <20180330111517.rrx6gs2skkgk336j@gmail.com>
[-- Attachment #1: Type: text/plain, Size: 3181 bytes --]
Hi Ingo,
Ingo Molnar <mingo@kernel.org> writes:
> * Shea Levy <shea@shealevy.com> wrote:
>
>> Now only those architectures that have custom initrd free requirements
>> need to define free_initrd_mem.
>>
>> Signed-off-by: Shea Levy <shea@shealevy.com>
>
> Please put the Kconfig symbol name this patch introduces both into the title, so
> that people know what to grep for.
>
>> ---
>> arch/alpha/mm/init.c | 8 --------
>> arch/arc/mm/init.c | 7 -------
>> arch/arm/Kconfig | 1 +
>> arch/arm64/Kconfig | 1 +
>> arch/blackfin/Kconfig | 1 +
>> arch/c6x/mm/init.c | 7 -------
>> arch/cris/Kconfig | 1 +
>> arch/frv/mm/init.c | 11 -----------
>> arch/h8300/mm/init.c | 7 -------
>> arch/hexagon/Kconfig | 1 +
>> arch/ia64/Kconfig | 1 +
>> arch/m32r/Kconfig | 1 +
>> arch/m32r/mm/init.c | 11 -----------
>> arch/m68k/mm/init.c | 7 -------
>> arch/metag/Kconfig | 1 +
>> arch/microblaze/mm/init.c | 7 -------
>> arch/mips/Kconfig | 1 +
>> arch/mn10300/Kconfig | 1 +
>> arch/nios2/mm/init.c | 7 -------
>> arch/openrisc/mm/init.c | 7 -------
>> arch/parisc/mm/init.c | 7 -------
>> arch/powerpc/mm/mem.c | 7 -------
>> arch/riscv/mm/init.c | 6 ------
>> arch/s390/Kconfig | 1 +
>> arch/score/Kconfig | 1 +
>> arch/sh/mm/init.c | 7 -------
>> arch/sparc/Kconfig | 1 +
>> arch/tile/Kconfig | 1 +
>> arch/um/kernel/mem.c | 7 -------
>> arch/unicore32/Kconfig | 1 +
>> arch/x86/Kconfig | 1 +
>> arch/xtensa/Kconfig | 1 +
>> init/initramfs.c | 7 +++++++
>> usr/Kconfig | 4 ++++
>> 34 files changed, 28 insertions(+), 113 deletions(-)
>
> Please also put it into Documentation/features/.
>
I switched this patch series (the latest revision v6 was just posted) to
using weak symbols instead of Kconfig. Does it still warrant documentation?
>
>> diff --git a/usr/Kconfig b/usr/Kconfig
>> index 43658b8a975e..7a94f6df39bf 100644
>> --- a/usr/Kconfig
>> +++ b/usr/Kconfig
>> @@ -233,3 +233,7 @@ config INITRAMFS_COMPRESSION
>> default ".lzma" if RD_LZMA
>> default ".bz2" if RD_BZIP2
>> default ""
>> +
>> +config HAVE_ARCH_FREE_INITRD_MEM
>> + bool
>> + default n
>
> Help text would be nice, to tell arch maintainers what the purpose of this switch
> is.
>
> Also, a nit, I think this should be named "ARCH_HAS_FREE_INITRD_MEM", which is the
> dominant pattern:
>
> triton:~/tip> git grep 'select.*ARCH' arch/x86/Kconfig* | cut -f2 | cut -d_ -f1-2 | sort | uniq -c | sort -n
> ...
> 2 select ARCH_USES
> 2 select ARCH_WANTS
> 3 select ARCH_MIGHT
> 3 select ARCH_WANT
> 4 select ARCH_SUPPORTS
> 4 select ARCH_USE
> 16 select HAVE_ARCH
> 23 select ARCH_HAS
>
> It also reads nicely in English:
>
> "arch has free_initrd_mem()"
>
> While the other makes little sense:
>
> "have arch free_initrd_mem()"
>
> ?
>
> Thanks,
>
> Ingo
Thanks,
Shea
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^ permalink raw reply
* Re: [PATCH] Extract initrd free logic from arch-specific code.
From: Ingo Molnar @ 2018-04-02 5:59 UTC (permalink / raw)
To: Shea Levy
Cc: linux-riscv, linux-kernel, Christoph Hellwig, Richard Henderson,
Ivan Kokshaysky, Matt Turner, Vineet Gupta, Russell King,
Catalin Marinas, Will Deacon, Mark Salter, Aurelien Jacquiot,
Mikael Starvik, Jesper Nilsson, Yoshinori Sato, Richard Kuo,
Tony Luck, Fenghua Yu, Geert Uytterhoeven, James Hogan,
Michal Simek, Ralf Baechle, David Howells, Ley Foon Tan,
Jonas Bonn, Stefan Kristiansson, Stafford Horne,
James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
Paul Mackerras, Michael Ellerman, Palmer Dabbelt, Albert Ou,
Martin Schwidefsky, Heiko Carstens, Chen Liqin, Lennox Wu,
Rich Felker, David S. Miller, Jeff Dike, Richard Weinberger,
Guan Xuetao, Thomas Gleixner, Ingo Molnar, H. Peter Anvin, x86,
Chris Zankel, Max Filippov, Kate Stewart, Greg Kroah-Hartman,
Philippe Ombredanne, Eugeniy Paltsev, Al Viro, Vladimir Murzin,
Linus Walleij, Michal Hocko, Andrew Morton, Sudip Mukherjee,
Marc Zyngier, Rob Herring, Kees Cook, Vlastimil Babka,
Balbir Singh, Christophe Leroy, Joe Perches,
Oliver O'Halloran, Dan Williams, Wei Yang,
Christian König, Arnd Bergmann, Deepa Dinamani,
Daniel Thompson, Rob Landley, Florian Fainelli, linux-alpha,
linux-snps-arc, linux-arm-kernel, adi-buildroot-devel,
linux-c6x-dev, linux-cris-kernel, uclinux-h8-devel, linux-hexagon,
linux-ia64, linux-m68k, linux-metag, linux-mips, linux-am33-list,
nios2-dev, openrisc, linux-parisc, linuxppc-dev, linux-s390,
linux-sh, sparclinux, user-mode-linux-devel, user-mode-linux-user,
linux-xtensa
In-Reply-To: <87bmf3rmq6.fsf@xps13.shealevy.com>
* Shea Levy <shea@shealevy.com> wrote:
> > Please also put it into Documentation/features/.
>
> I switched this patch series (the latest revision v6 was just posted) to
> using weak symbols instead of Kconfig. Does it still warrant documentation?
Probably not.
Thanks,
Ingo
^ permalink raw reply
* [PATCH v3 0/7] powerpc/fadump: Improvements and fixes for firmware-assisted dump.
From: Mahesh J Salgaonkar @ 2018-04-02 6:29 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
One of the primary issues with Firmware Assisted Dump (fadump) on Power
is that it needs a large amount of memory to be reserved. This reserved
memory is used for saving the contents of old crashed kernel's memory before
fadump capture kernel uses old kernel's memory area to boot. However, This
reserved memory area stays unused until system crash and isn't available
for production kernel to use.
Instead of setting aside a significant chunk of memory that nobody can use,
take advantage Linux kernel's Contiguous Memory Allocator (CMA) feature,
to reserve a significant chunk of memory that the kernel is prevented from
using , but applications are free to use it.
Patch 1 moves the metadata region to the start of the reserved area for easy
handling/detection of metadata region in second kernel.
Patch 3 implements the usage of CMA region to allow production kernel to
use that memory for applications usage, making fadump reservationless.
Patch 4-7 fixes various fadump issues and bugs.
Changes in V3:
- patch 1 & 2: move metadata region and documentation update.
- patch 7: Un-register the faudmp on kexec path
---
Mahesh Salgaonkar (7):
powerpc/fadump: Move the metadata region to start of the reserved area.
powerpc/fadump: Update documentation to reflect the metadata region movement.
powerpc/fadump: Reservationless firmware assisted dump
powerpc/fadump: exclude memory holes while reserving memory in second kernel.
powerpc/fadump: throw proper error message on fadump registration failure.
powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.
powerpc/fadump: un-register fadump on kexec path.
Documentation/powerpc/firmware-assisted-dump.txt | 31 ++
arch/powerpc/include/asm/fadump.h | 6
arch/powerpc/kernel/fadump.c | 275 +++++++++++++++++++---
arch/powerpc/platforms/pseries/hotplug-memory.c | 7 -
4 files changed, 271 insertions(+), 48 deletions(-)
--
Signature
^ permalink raw reply
* [PATCH v3 1/7] powerpc/fadump: Move the metadata region to start of the reserved area.
From: Mahesh J Salgaonkar @ 2018-04-02 6:29 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Currently the metadata region that holds crash info structure and ELF core
header is placed towards the end of reserved memory area. This patch places
it at the beginning of the reserved memory area.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/fadump.h | 4 ++
arch/powerpc/kernel/fadump.c | 92 ++++++++++++++++++++++++++++++++-----
2 files changed, 83 insertions(+), 13 deletions(-)
diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h
index 5a23010af600..44b6ebfe9be6 100644
--- a/arch/powerpc/include/asm/fadump.h
+++ b/arch/powerpc/include/asm/fadump.h
@@ -61,6 +61,9 @@
#define FADUMP_UNREGISTER 2
#define FADUMP_INVALIDATE 3
+/* Number of dump sections requested by kernel */
+#define FADUMP_NUM_SECTIONS 4
+
/* Dump status flag */
#define FADUMP_ERROR_FLAG 0x2000
@@ -119,6 +122,7 @@ struct fadump_mem_struct {
struct fadump_section cpu_state_data;
struct fadump_section hpte_region;
struct fadump_section rmr_region;
+ struct fadump_section metadata_region;
};
/* Firmware-assisted dump configuration details. */
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 3c2c2688918f..80552fd7d5f8 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -188,17 +188,48 @@ static void fadump_show_config(void)
pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size);
}
+static unsigned long get_fadump_metadata_size(void)
+{
+ unsigned long size = 0;
+
+ /*
+ * If fadump is active then look into fdm_active to get metadata
+ * size set by previous kernel.
+ */
+ if (fw_dump.dump_active) {
+ size = fdm_active->cpu_state_data.destination_address -
+ fdm_active->metadata_region.source_address;
+ goto out;
+ }
+ size += sizeof(struct fadump_crash_info_header);
+ size += sizeof(struct elfhdr); /* ELF core header.*/
+ size += sizeof(struct elf_phdr); /* place holder for cpu notes */
+ /* Program headers for crash memory regions. */
+ size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
+
+ size = PAGE_ALIGN(size);
+out:
+ pr_debug("fadump Metadata size is %ld\n", size);
+ return size;
+}
+
static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
unsigned long addr)
{
+ uint16_t num_sections = 0;
+ unsigned long metadata_base = 0;
+
if (!fdm)
return 0;
+ /* Skip the fadump metadata area. */
+ metadata_base = addr;
+ addr += get_fadump_metadata_size();
+
memset(fdm, 0, sizeof(struct fadump_mem_struct));
addr = addr & PAGE_MASK;
fdm->header.dump_format_version = cpu_to_be32(0x00000001);
- fdm->header.dump_num_sections = cpu_to_be16(3);
fdm->header.dump_status_flag = 0;
fdm->header.offset_first_dump_section =
cpu_to_be32((u32)offsetof(struct fadump_mem_struct, cpu_state_data));
@@ -222,6 +253,7 @@ static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
fdm->cpu_state_data.source_address = 0;
fdm->cpu_state_data.source_len = cpu_to_be64(fw_dump.cpu_state_data_size);
fdm->cpu_state_data.destination_address = cpu_to_be64(addr);
+ num_sections++;
addr += fw_dump.cpu_state_data_size;
/* hpte region section */
@@ -230,6 +262,7 @@ static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
fdm->hpte_region.source_address = 0;
fdm->hpte_region.source_len = cpu_to_be64(fw_dump.hpte_region_size);
fdm->hpte_region.destination_address = cpu_to_be64(addr);
+ num_sections++;
addr += fw_dump.hpte_region_size;
/* RMA region section */
@@ -238,8 +271,25 @@ static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm,
fdm->rmr_region.source_address = cpu_to_be64(RMA_START);
fdm->rmr_region.source_len = cpu_to_be64(fw_dump.boot_memory_size);
fdm->rmr_region.destination_address = cpu_to_be64(addr);
+ num_sections++;
addr += fw_dump.boot_memory_size;
+ /*
+ * fadump metadata section.
+ * Add an entry with source len a zero. We are only intereseted in
+ * source address which will help us to detect the location of
+ * metadata area where faump header and elf core header is placed.
+ */
+ fdm->metadata_region.request_flag = cpu_to_be32(FADUMP_REQUEST_FLAG);
+ fdm->metadata_region.source_data_type =
+ cpu_to_be16(FADUMP_REAL_MODE_REGION);
+ fdm->metadata_region.source_address = cpu_to_be64(metadata_base);
+ fdm->metadata_region.source_len = 0;
+ fdm->metadata_region.destination_address = cpu_to_be64(addr);
+ num_sections++;
+
+ fdm->header.dump_num_sections = cpu_to_be16(num_sections);
+ BUILD_BUG_ON(num_sections != FADUMP_NUM_SECTIONS);
return addr;
}
@@ -325,16 +375,17 @@ static unsigned long get_fadump_area_size(void)
size += fw_dump.cpu_state_data_size;
size += fw_dump.hpte_region_size;
size += fw_dump.boot_memory_size;
- size += sizeof(struct fadump_crash_info_header);
- size += sizeof(struct elfhdr); /* ELF core header.*/
- size += sizeof(struct elf_phdr); /* place holder for cpu notes */
- /* Program headers for crash memory regions. */
- size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2);
-
+ size += get_fadump_metadata_size();
size = PAGE_ALIGN(size);
return size;
}
+static inline unsigned long get_fadump_metadata_base(
+ const struct fadump_mem_struct *fdm)
+{
+ return be64_to_cpu(fdm->metadata_region.source_address);
+}
+
int __init fadump_reserve_mem(void)
{
unsigned long base, size, memory_boundary;
@@ -395,9 +446,9 @@ int __init fadump_reserve_mem(void)
(unsigned long)(size >> 20),
(unsigned long)(base >> 20));
- fw_dump.fadumphdr_addr =
- be64_to_cpu(fdm_active->rmr_region.destination_address) +
- be64_to_cpu(fdm_active->rmr_region.source_len);
+ pr_info("Number of kernel Dump sections: %d\n",
+ be16_to_cpu(fdm_active->header.dump_num_sections));
+ fw_dump.fadumphdr_addr = get_fadump_metadata_base(fdm_active);
pr_debug("fadumphdr_addr = %p\n",
(void *) fw_dump.fadumphdr_addr);
} else {
@@ -803,14 +854,24 @@ static int __init fadump_build_cpu_notes(const struct fadump_mem_struct *fdm)
static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
{
struct fadump_crash_info_header *fdh;
+ uint16_t num_sections = 0;
int rc = 0;
if (!fdm_active || !fw_dump.fadumphdr_addr)
return -EINVAL;
+ /* Check if platform has honored all 4 dump sections requested. */
+ num_sections = be16_to_cpu(fdm_active->header.dump_num_sections);
+ if (num_sections < FADUMP_NUM_SECTIONS) {
+ printk(KERN_ERR "Dump taken by platform does not "
+ "contain all requested sections\n");
+ return -EINVAL;
+ }
+
/* Check if the dump data is valid. */
if ((be16_to_cpu(fdm_active->header.dump_status_flag) == FADUMP_ERROR_FLAG) ||
(fdm_active->cpu_state_data.error_flags != 0) ||
+ (fdm_active->metadata_region.error_flags != 0) ||
(fdm_active->rmr_region.error_flags != 0)) {
printk(KERN_ERR "Dump taken by platform is not valid\n");
return -EINVAL;
@@ -821,6 +882,11 @@ static int __init process_fadump(const struct fadump_mem_struct *fdm_active)
printk(KERN_ERR "Dump taken by platform is incomplete\n");
return -EINVAL;
}
+ if ((fdm_active->metadata_region.bytes_dumped !=
+ fdm_active->metadata_region.source_len)) {
+ printk(KERN_ERR "Dump taken by platform is incomplete\n");
+ return -EINVAL;
+ }
/* Validate the fadump crash info header */
fdh = __va(fw_dump.fadumphdr_addr);
@@ -1082,7 +1148,7 @@ static int register_fadump(void)
fadump_setup_crash_memory_ranges();
- addr = be64_to_cpu(fdm.rmr_region.destination_address) + be64_to_cpu(fdm.rmr_region.source_len);
+ addr = get_fadump_metadata_base(&fdm);
/* Initialize fadump crash info header. */
addr = init_fadump_header(addr);
vaddr = __va(addr);
@@ -1153,7 +1219,7 @@ void fadump_cleanup(void)
/* Invalidate the registration only if dump is active. */
if (fw_dump.dump_active) {
init_fadump_mem_struct(&fdm,
- be64_to_cpu(fdm_active->cpu_state_data.destination_address));
+ get_fadump_metadata_base(fdm_active));
fadump_invalidate_dump(&fdm);
}
}
@@ -1236,7 +1302,7 @@ static void fadump_invalidate_release_mem(void)
return;
}
- destination_address = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
+ destination_address = get_fadump_metadata_base(fdm_active);
fadump_cleanup();
mutex_unlock(&fadump_mutex);
^ permalink raw reply related
* [PATCH v3 2/7] powerpc/fadump: Update documentation to reflect the metadata region movement.
From: Mahesh J Salgaonkar @ 2018-04-02 6:30 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Metadata region that holds fadump header and ELF header is now placed at
the start of reserved memory area. Update the documentation accordingly
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
Documentation/powerpc/firmware-assisted-dump.txt | 31 +++++++++++++---------
1 file changed, 19 insertions(+), 12 deletions(-)
diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt
index bdd344aa18d9..c77f8dc9231f 100644
--- a/Documentation/powerpc/firmware-assisted-dump.txt
+++ b/Documentation/powerpc/firmware-assisted-dump.txt
@@ -115,17 +115,24 @@ be kept permanently reserved, so that it can act as a receptacle
for a copy of the boot memory content in addition to CPU state
and HPTE region, in the case a crash does occur.
+The first kernel, during fadump registration, prepares ELF core header
+that contains necessary information for the coredump of the 1st kernel
+which includes its physical memory layout. This ELF header and some more
+additional data is stored in the area called metadata region at the start
+of the reserved memory area.
+
o Memory Reservation during first kernel
Low memory Top of memory
0 boot memory size |
| | |<--Reserved dump area -->| |
V V | Permanent Reservation | V
- +-----------+----------/ /---+---+----+-----------+----+------+
- | | |CPU|HPTE| DUMP |ELF | |
- +-----------+----------/ /---+---+----+-----------+----+------+
- | ^
- | |
+ +-----------+----------/ /---+----+---+----+-----------+------+
+ | | |ELF |CPU|HPTE| DUMP | |
+ +-----------+---------/ /----+----+---+----+-----------+------+
+ | ^ ^
+ | | |
+ | metadata region |
\ /
-------------------------------------------
Boot memory content gets transferred to
@@ -137,14 +144,14 @@ and HPTE region, in the case a crash does occur.
Low memory Top of memory
0 boot memory size |
- | |<------------- Reserved dump area ----------- -->|
+ | |<------------- Reserved dump area -------------->|
V V V
- +-----------+----------/ /---+---+----+-----------+----+------+
- | | |CPU|HPTE| DUMP |ELF | |
- +-----------+----------/ /---+---+----+-----------+----+------+
- | |
- V V
- Used by second /proc/vmcore
+ +-----------+----------/ /---+----+----+---------------+------+
+ | | |ELF |CPU|HPTE| DUMP | |
+ +-----------+----------/ /---+----+----+---------------+------+
+ | |
+ V V
+ Used by second /proc/vmcore
kernel to boot
Fig. 2
^ permalink raw reply related
* [PATCH v3 3/7] powerpc/fadump: Reservationless firmware assisted dump
From: Mahesh J Salgaonkar @ 2018-04-02 6:30 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Ananth N Mavinakayanahalli,
Aneesh Kumar K.V, Ananth Narayan, Hari Bathini, Nathan Fontenot,
Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
One of the primary issues with Firmware Assisted Dump (fadump) on Power
is that it needs a large amount of memory to be reserved. On large
systems with TeraBytes of memory, this reservation can be quite
significant.
In some cases, fadump fails if the memory reserved is insufficient, or
if the reserved memory was DLPAR hot-removed.
In the normal case, post reboot, the preserved memory is filtered to
extract only relevant areas of interest using the makedumpfile tool.
While the tool provides flexibility to determine what needs to be part
of the dump and what memory to filter out, all supported distributions
default this to "Capture only kernel data and nothing else".
We take advantage of this default and the Linux kernel's Contiguous
Memory Allocator (CMA) to fundamentally change the memory reservation
model for fadump. Fadump can now only capture kernel memory.
Instead of setting aside a significant chunk of memory nobody can use,
this patch uses CMA instead, to reserve a significant chunk of memory
that the kernel is prevented from using (due to MIGRATE_CMA), but
applications are free to use it.
Essentially, on a P9 LPAR with 2 cores, 8GB RAM and current upstream:
[root@zzxx-yy10 ~]# free -m
total used free shared buff/cache available
Mem: 7557 193 6822 12 541 6725
Swap: 4095 0 4095
With this patch:
[root@zzxx-yy10 ~]# free -m
total used free shared buff/cache available
Mem: 8133 194 7464 12 475 7338
Swap: 4095 0 4095
Changes made here are completely transparent to how fadump has
traditionally worked.
Thanks to Aneesh Kumar and Anshuman Khandual for helping us understand
CMA and its usage.
TODO:
- Handle case where CMA reservation spans nodes.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
arch/powerpc/kernel/fadump.c | 122 ++++++++++++++++++++++++++++++++++++------
1 file changed, 104 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 80552fd7d5f8..011f1aa7abab 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -34,6 +34,7 @@
#include <linux/crash_dump.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
+#include <linux/cma.h>
#include <asm/debugfs.h>
#include <asm/page.h>
@@ -45,11 +46,57 @@
static struct fw_dump fw_dump;
static struct fadump_mem_struct fdm;
static const struct fadump_mem_struct *fdm_active;
+static struct cma *fadump_cma;
static DEFINE_MUTEX(fadump_mutex);
struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES];
int crash_mem_ranges;
+/*
+ * fadump_cma_reserve() - reserve area for fadump memory reservation
+ *
+ * This function reserves memory from early allocator. It should be
+ * called by arch specific code once the memblock allocator
+ * has been activated.
+ */
+int __init fadump_cma_reserve(void)
+{
+ unsigned long long base, size;
+ int rc;
+
+ if (!fw_dump.fadump_enabled)
+ return 0;
+
+ base = fw_dump.reserve_dump_area_start;
+ size = fw_dump.reserve_dump_area_size;
+ pr_debug("Original reserve area base %ld, size %ld\n",
+ (unsigned long)base >> 20,
+ (unsigned long)size >> 20);
+ if (!size)
+ return 0;
+
+ rc = cma_declare_contiguous(base, size, 0, 0, 0, false,
+ "fadump_cma", &fadump_cma);
+ if (rc) {
+ printk(KERN_ERR "fadump: Failed to reserve cma area for "
+ "firmware-assisted dump, %d\n", rc);
+ fw_dump.reserve_dump_area_size = 0;
+ return 0;
+ }
+ /*
+ * So we now have cma area reserved for fadump. base may be different
+ * from what we requested.
+ */
+ fw_dump.reserve_dump_area_start = cma_get_base(fadump_cma);
+ fw_dump.reserve_dump_area_size = cma_get_size(fadump_cma);
+ printk("Reserved %ldMB cma area at %ldMB for firmware-assisted dump "
+ "(System RAM: %ldMB)\n",
+ cma_get_size(fadump_cma) >> 20,
+ (unsigned long)cma_get_base(fadump_cma) >> 20,
+ (unsigned long)(memblock_phys_mem_size() >> 20));
+ return 1;
+}
+
/* Scan the Firmware Assisted dump configuration details. */
int __init early_init_dt_scan_fw_dump(unsigned long node,
const char *uname, int depth, void *data)
@@ -381,7 +428,7 @@ static unsigned long get_fadump_area_size(void)
}
static inline unsigned long get_fadump_metadata_base(
- const struct fadump_mem_struct *fdm)
+ const struct fadump_mem_struct *fdm)
{
return be64_to_cpu(fdm->metadata_region.source_address);
}
@@ -449,8 +496,9 @@ int __init fadump_reserve_mem(void)
pr_info("Number of kernel Dump sections: %d\n",
be16_to_cpu(fdm_active->header.dump_num_sections));
fw_dump.fadumphdr_addr = get_fadump_metadata_base(fdm_active);
- pr_debug("fadumphdr_addr = %p\n",
- (void *) fw_dump.fadumphdr_addr);
+ pr_debug("fadumphdr_addr = %pa\n", &fw_dump.fadumphdr_addr);
+ fw_dump.reserve_dump_area_start = base;
+ fw_dump.reserve_dump_area_size = size;
} else {
size = get_fadump_area_size();
@@ -467,21 +515,10 @@ int __init fadump_reserve_mem(void)
!memblock_is_region_reserved(base, size))
break;
}
- if ((base > (memory_boundary - size)) ||
- memblock_reserve(base, size)) {
- pr_err("Failed to reserve memory\n");
- return 0;
- }
-
- pr_info("Reserved %ldMB of memory at %ldMB for firmware-"
- "assisted dump (System RAM: %ldMB)\n",
- (unsigned long)(size >> 20),
- (unsigned long)(base >> 20),
- (unsigned long)(memblock_phys_mem_size() >> 20));
+ fw_dump.reserve_dump_area_start = base;
+ fw_dump.reserve_dump_area_size = size;
+ return fadump_cma_reserve();
}
-
- fw_dump.reserve_dump_area_start = base;
- fw_dump.reserve_dump_area_size = size;
return 1;
}
@@ -1134,6 +1171,39 @@ static unsigned long init_fadump_header(unsigned long addr)
return addr;
}
+static unsigned long allocate_metadata_area(void)
+{
+ int nr_pages;
+ unsigned long size;
+ struct page *page = NULL;
+
+ /*
+ * Check if fadump cma region is activated.
+ * fadump_cma->count == 0 means cma activation has failed. This means
+ * that the fadump reserved memory now will not be visible/available
+ * for user applications to use. It will be as good as old fadump
+ * behaviour of blocking this memory chunk from production system
+ * use. CMA activation failure does not mean that fadump will not
+ * work. Will continue to setup fadump.
+ */
+ if (!fadump_cma || !cma_get_size(fadump_cma)) {
+ pr_warn("fadump cma region activation failed.\n");
+ return 0;
+ }
+
+ size = get_fadump_metadata_size();
+ nr_pages = ALIGN(size, PAGE_SIZE) >> PAGE_SHIFT;
+ pr_info("Fadump metadata size = %ld (nr_pages = %d)\n", size, nr_pages);
+
+ page = cma_alloc(fadump_cma, nr_pages, 0, GFP_KERNEL);
+ if (page) {
+ pr_debug("Allocated fadump metadata area at %ldMB (cma)\n",
+ (unsigned long)page_to_phys(page) >> 20);
+ return page_to_phys(page);
+ }
+ return 0;
+}
+
static int register_fadump(void)
{
unsigned long addr;
@@ -1556,8 +1626,24 @@ int __init setup_fadump(void)
fadump_invalidate_release_mem();
}
/* Initialize the kernel dump memory structure for FAD registration. */
- else if (fw_dump.reserve_dump_area_size)
+ else if (fw_dump.reserve_dump_area_size) {
+ /*
+ * By this time cma area has been activated. Allocate memory
+ * for metadata from fadump cma region. Since this is very
+ * early during boot we are guaranteed to get metadata cma
+ * allocation at address fw_dump.reserve_dump_area_start.
+ *
+ * During fadump registration, metadata region is used
+ * to setup fadump header and ELF core header. We don't want
+ * this region to be touched by anyone. Allocating metadata
+ * region memory from fadump cma will make sure that this
+ * region will not given to any user space application.
+ * However the rest of the fadump cma memory is still free
+ * to be used by user applications.
+ */
+ allocate_metadata_area();
init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start);
+ }
fadump_init_files();
return 1;
^ permalink raw reply related
* [PATCH v3 4/7] powerpc/fadump: exclude memory holes while reserving memory in second kernel.
From: Mahesh J Salgaonkar @ 2018-04-02 6:30 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
The second kernel, during early boot after the crash, reserves rest of
the memory above boot memory size to make sure it does not touch any of the
dump memory area. It uses memblock_reserve() that reserves the specified
memory region irrespective of memory holes present within that region.
There are chances where previous kernel would have hot removed some of
its memory leaving memory holes behind. In such cases fadump kernel reports
incorrect number of reserved pages through arch_reserved_kernel_pages()
hook causing kernel to hang or panic.
Fix this by excluding memory holes while reserving rest of the memory
above boot memory size during second kernel boot after crash.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
arch/powerpc/kernel/fadump.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 011f1aa7abab..a497e9fb93fe 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -433,6 +433,21 @@ static inline unsigned long get_fadump_metadata_base(
return be64_to_cpu(fdm->metadata_region.source_address);
}
+static void fadump_memblock_reserve(unsigned long base, unsigned long size)
+{
+ struct memblock_region *reg;
+ unsigned long start, end;
+
+ for_each_memblock(memory, reg) {
+ start = max(base, (unsigned long)reg->base);
+ end = reg->base + reg->size;
+ end = min(base + size, end);
+
+ if (start < end)
+ memblock_reserve(start, end - start);
+ }
+}
+
int __init fadump_reserve_mem(void)
{
unsigned long base, size, memory_boundary;
@@ -487,7 +502,7 @@ int __init fadump_reserve_mem(void)
*/
base = fw_dump.boot_memory_size;
size = memory_boundary - base;
- memblock_reserve(base, size);
+ fadump_memblock_reserve(base, size);
printk(KERN_INFO "Reserved %ldMB of memory at %ldMB "
"for saving crash dump\n",
(unsigned long)(size >> 20),
^ permalink raw reply related
* [PATCH v3 5/7] powerpc/fadump: throw proper error message on fadump registration failure.
From: Mahesh J Salgaonkar @ 2018-04-02 6:30 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
fadump fails to register when there are holes in reserved memory area.
This can happen if user has hot-removed a memory that falls in the fadump
reserved memory area. Throw a meaningful error message to the user in
such case.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
arch/powerpc/kernel/fadump.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index a497e9fb93fe..59aaf0357a52 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -216,6 +216,36 @@ static int is_boot_memory_area_contiguous(void)
return ret;
}
+/*
+ * Returns 1, if there are no holes in reserved memory area,
+ * 0 otherwise.
+ */
+static int is_reserved_memory_area_contiguous(void)
+{
+ struct memblock_region *reg;
+ unsigned long start, end;
+ unsigned long d_start = fw_dump.reserve_dump_area_start;
+ unsigned long d_end = d_start + fw_dump.reserve_dump_area_size;
+ int ret = 0;
+
+ for_each_memblock(memory, reg) {
+ start = max(d_start, (unsigned long)reg->base);
+ end = min(d_end, (unsigned long)(reg->base + reg->size));
+ if (d_start < end) {
+ /* Memory hole from d_start to start */
+ if (start > d_start)
+ break;
+
+ if (end == d_end) {
+ ret = 1;
+ break;
+ }
+ d_start = end + 1;
+ }
+ }
+ return ret;
+}
+
/* Print firmware assisted dump configurations for debugging purpose. */
static void fadump_show_config(void)
{
@@ -602,6 +632,9 @@ static int register_fw_dump(struct fadump_mem_struct *fdm)
if (!is_boot_memory_area_contiguous())
pr_err("Can't have holes in boot memory area while "
"registering fadump\n");
+ else if (!is_reserved_memory_area_contiguous())
+ pr_err("Can't have holes in reserved memory area while"
+ " registering fadump\n");
printk(KERN_ERR "Failed to register firmware-assisted kernel"
" dump. Parameter Error(%d).\n", rc);
^ permalink raw reply related
* [PATCH v3 6/7] powerpc/fadump: Do not allow hot-remove memory from fadump reserved area.
From: Mahesh J Salgaonkar @ 2018-04-02 6:30 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
For fadump to work successfully there should not be any holes in reserved
memory ranges where kernel has asked firmware to move the content of old
kernel memory in event of crash. But this memory area is currently not
protected from hot-remove operations. Hence, fadump service can fail to
re-register after the hot-remove operation, if hot-removed memory belongs
to fadump reserved region. To avoid this make sure that memory from fadump
reserved area is not hot-removable if fadump is registered.
However, if user still wants to remove that memory, he can do so by
manually stopping fadump service before hot-remove operation.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
arch/powerpc/include/asm/fadump.h | 2 +-
arch/powerpc/kernel/fadump.c | 10 ++++++++--
arch/powerpc/platforms/pseries/hotplug-memory.c | 7 +++++--
3 files changed, 14 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h
index 44b6ebfe9be6..d16dc77107a8 100644
--- a/arch/powerpc/include/asm/fadump.h
+++ b/arch/powerpc/include/asm/fadump.h
@@ -207,7 +207,7 @@ struct fad_crash_memory_ranges {
unsigned long long size;
};
-extern int is_fadump_boot_memory_area(u64 addr, ulong size);
+extern int is_fadump_memory_area(u64 addr, ulong size);
extern int early_init_dt_scan_fw_dump(unsigned long node,
const char *uname, int depth, void *data);
extern int fadump_reserve_mem(void);
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 59aaf0357a52..2c3c7e655eec 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -162,13 +162,19 @@ int __init early_init_dt_scan_fw_dump(unsigned long node,
/*
* If fadump is registered, check if the memory provided
- * falls within boot memory area.
+ * falls within boot memory area and reserved memory area.
*/
-int is_fadump_boot_memory_area(u64 addr, ulong size)
+int is_fadump_memory_area(u64 addr, ulong size)
{
+ u64 d_start = fw_dump.reserve_dump_area_start;
+ u64 d_end = d_start + fw_dump.reserve_dump_area_size;
+
if (!fw_dump.dump_registered)
return 0;
+ if (((addr + size) > d_start) && (addr <= d_end))
+ return 1;
+
return (addr + size) > RMA_START && addr <= fw_dump.boot_memory_size;
}
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index c1578f54c626..e4c658cda3a7 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -389,8 +389,11 @@ static bool lmb_is_removable(struct drmem_lmb *lmb)
phys_addr = lmb->base_addr;
#ifdef CONFIG_FA_DUMP
- /* Don't hot-remove memory that falls in fadump boot memory area */
- if (is_fadump_boot_memory_area(phys_addr, block_sz))
+ /*
+ * Don't hot-remove memory that falls in fadump boot memory area
+ * and memory that is reserved for capturing old kernel memory.
+ */
+ if (is_fadump_memory_area(phys_addr, block_sz))
return false;
#endif
^ permalink raw reply related
* [PATCH v3 7/7] powerpc/fadump: un-register fadump on kexec path.
From: Mahesh J Salgaonkar @ 2018-04-02 6:30 UTC (permalink / raw)
To: linuxppc-dev
Cc: Srikar Dronamraju, kernelfans, Aneesh Kumar K.V, Ananth Narayan,
Hari Bathini, Nathan Fontenot, Anshuman Khandual
In-Reply-To: <152265046485.23251.1392824827444770657.stgit@jupiter.in.ibm.com>
From: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
otherwise the fadump registration in new kexec-ed kernel complains that
fadump is already registered. This makes new kernel to continue using
fadump registered by previous kernel which may lead to invalid vmcore
generation. Hence this patch fixes this issue by un-registering fadump
in fadump_cleanup() which is called during kexec path so that new kernel
can register fadump with new valid values.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
---
arch/powerpc/kernel/fadump.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 2c3c7e655eec..cb496c8f40f3 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -1345,6 +1345,9 @@ void fadump_cleanup(void)
init_fadump_mem_struct(&fdm,
get_fadump_metadata_base(fdm_active));
fadump_invalidate_dump(&fdm);
+ } else if (fw_dump.dump_registered) {
+ /* Un-register Firmware-assisted dump if it was registered. */
+ fadump_unregister_dump(&fdm);
}
}
^ permalink raw reply related
* [PATCH] powerpc: Fix oops due to deferral of lpacca on non virtualized platform
From: Aneesh Kumar K.V @ 2018-04-02 7:30 UTC (permalink / raw)
To: benh, paulus, mpe, npiggin; +Cc: linuxppc-dev, Aneesh Kumar K.V
Commit 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not
virtualized") removed allocation of lppaca on non virtualized platform. But with
CONFIG_PPC_SPLPAR enabled, we do access lppaca non-virtualized platform in some
code paths.
Fix this but adding runtime check for virtualized platform.
Fixes: 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not virtualized")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
arch/powerpc/include/asm/lppaca.h | 3 +++
arch/powerpc/include/asm/spinlock.h | 2 ++
arch/powerpc/kernel/time.c | 3 +++
3 files changed, 8 insertions(+)
diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h
index 65d589689f01..7c23ce8a5a4c 100644
--- a/arch/powerpc/include/asm/lppaca.h
+++ b/arch/powerpc/include/asm/lppaca.h
@@ -34,6 +34,7 @@
#include <linux/threads.h>
#include <asm/types.h>
#include <asm/mmu.h>
+#include <asm/firmware.h>
/*
* The lppaca is the "virtual processor area" registered with the hypervisor,
@@ -114,6 +115,8 @@ struct lppaca {
static inline bool lppaca_shared_proc(struct lppaca *l)
{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return false;
return !!(l->__old_status & LPPACA_OLD_SHARED_PROC);
}
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index b9ebc3085fb7..72dc4ddc2972 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -56,6 +56,8 @@
#define vcpu_is_preempted vcpu_is_preempted
static inline bool vcpu_is_preempted(int cpu)
{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return false;
return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1);
}
#endif
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index f7d96a68ecaa..360e71d455cc 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -266,6 +266,9 @@ void accumulate_stolen_time(void)
static inline u64 calculate_stolen_time(u64 stop_tb)
{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return 0;
+
if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
return scan_dispatch_log(stop_tb);
--
2.14.3
^ permalink raw reply related
* [PATCH V2] powerpc: Fix oops due to wrong access of lppaca on non virtualized platform
From: Aneesh Kumar K.V @ 2018-04-02 7:33 UTC (permalink / raw)
To: benh, paulus, mpe, npiggin; +Cc: linuxppc-dev, Aneesh Kumar K.V
Commit 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not
virtualized") removed allocation of lppaca on non virtualized platform. But with
CONFIG_PPC_SPLPAR enabled, we do access lppaca non-virtualized platform in some
code paths.
Fix this but adding runtime check for virtualized platform.
Fixes: 8e0b634b1327 ("powerpc/64s: Do not allocate lppaca if we are not virtualized")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
Changes from V1:
* update commit summary
arch/powerpc/include/asm/lppaca.h | 3 +++
arch/powerpc/include/asm/spinlock.h | 2 ++
arch/powerpc/kernel/time.c | 3 +++
3 files changed, 8 insertions(+)
diff --git a/arch/powerpc/include/asm/lppaca.h b/arch/powerpc/include/asm/lppaca.h
index 65d589689f01..7c23ce8a5a4c 100644
--- a/arch/powerpc/include/asm/lppaca.h
+++ b/arch/powerpc/include/asm/lppaca.h
@@ -34,6 +34,7 @@
#include <linux/threads.h>
#include <asm/types.h>
#include <asm/mmu.h>
+#include <asm/firmware.h>
/*
* The lppaca is the "virtual processor area" registered with the hypervisor,
@@ -114,6 +115,8 @@ struct lppaca {
static inline bool lppaca_shared_proc(struct lppaca *l)
{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return false;
return !!(l->__old_status & LPPACA_OLD_SHARED_PROC);
}
diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index b9ebc3085fb7..72dc4ddc2972 100644
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -56,6 +56,8 @@
#define vcpu_is_preempted vcpu_is_preempted
static inline bool vcpu_is_preempted(int cpu)
{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return false;
return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1);
}
#endif
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index f7d96a68ecaa..360e71d455cc 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -266,6 +266,9 @@ void accumulate_stolen_time(void)
static inline u64 calculate_stolen_time(u64 stop_tb)
{
+ if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+ return 0;
+
if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
return scan_dispatch_log(stop_tb);
--
2.14.3
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