From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 00/10] arm64 kexec kernel patches V5
Date: Fri, 7 Nov 2014 10:16:42 +0000 [thread overview]
Message-ID: <20141107101642.GA4585@leverpostej> (raw)
In-Reply-To: <CACxGe6u=J_k3XZxyiyti=i=rtW+a5xxuukg3TgOyM+ra1vAACQ@mail.gmail.com>
On Fri, Nov 07, 2014 at 12:41:45AM +0000, Grant Likely wrote:
> On Thu, Nov 6, 2014 at 3:08 PM, Mark Rutland <mark.rutland@arm.com> wrote:
> > On Thu, Nov 06, 2014 at 01:56:42AM +0000, Dave Young wrote:
> >> On 11/03/14 at 07:46pm, Mark Rutland wrote:
> >> > On Fri, Oct 31, 2014 at 07:52:09AM +0000, Dave Young wrote:
> >> > > Hi Geoff
> >> > >
> >> > > I tested your patches. The macihne is using spin-table cpu enable method
> >> > > so I tried maxcpus=1 as you suggested.
> >> > >
> >> > > There's below issues for me, thoughts?
> >> > >
> >> > > 1. For acpi booting there's no /proc/device-tree so kexec can not find dtb
> >> > > to use.
> >> >
> >> > Are you absolutely certain of this?
> >> >
> >> > To use ACPI, you must have booted via EFI, as the only mechanism for
> >> > finding the ACPI tables is via EFI. If booted via EFI, the stub will
> >> > have created a stub DTB if there is no provided DTB, to pass the command
> >> > line and pointers to EFI data structures. This stub DTB should be
> >> > present in the usual place.
> >>
> >> Mark, I used kexec-tools from Geoff's git tree, it will create dtb from procfs
> >> maybe I can pass external dtb to kexec-tools. What you mentioned should be true
> >> though but I have not get idea how to get the dtb which kernel is using for boot
> >> since it is not unflattened.
> >
> > Ah, sorry. I see the problem now. For ACPI you don't unflatten the tree,
> > so there's nothing to expose at in sysfs/procfs.
> >
> > Somehow we need to unflatten the DTB without exposing it to drivers,
> > such that it can be exposed to userspace in the usual place but drivers
> > don't being probing based off of it.
>
> Is that even necessary? If the tree isn't unflattened, then it is just
> a stub tree. There really isn't anything interesting in it.
We need to UEFI properties [1] from /chosen to access the memory map and
system table (both of which are necessary to access any ACPI tables).
> Kexec should recreate the tree from scratch in that case.
I'm not sure if the required information is exposed to userspace
elsewhere. Ard, Leif?
Mark.
[1] Documentation/arm/uefi.txt
next prev parent reply other threads:[~2014-11-07 10:16 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-23 23:10 [PATCH 00/10] arm64 kexec kernel patches V5 Geoff Levand
2014-10-23 23:10 ` [PATCH 02/10] arm64: Convert hcalls to use ISS field Geoff Levand
2014-10-23 23:10 ` [PATCH 07/10] arm64: Move proc-macros.S to include/asm Geoff Levand
2014-10-23 23:10 ` [PATCH 03/10] arm64: Add new hcall HVC_CALL_FUNC Geoff Levand
2014-10-23 23:10 ` [PATCH 05/10] arm64: Convert dts to use reserved-memory nodes Geoff Levand
2014-10-24 10:51 ` Mark Rutland
2014-10-24 10:59 ` Grant Likely
2014-10-24 12:27 ` Mark Rutland
2014-10-24 14:45 ` Grant Likely
2014-10-31 23:44 ` Geoff Levand
2014-11-03 20:02 ` Mark Rutland
2014-11-03 22:26 ` Rob Herring
2014-11-04 11:35 ` Mark Rutland
2014-11-04 11:37 ` Grant Likely
2014-10-23 23:10 ` [PATCH 01/10] arm64/kvm: Fix assembler compatibility of macros Geoff Levand
2014-10-24 9:24 ` Mark Rutland
2014-10-27 12:13 ` Will Deacon
2014-10-27 12:45 ` Christoffer Dall
2014-10-31 23:06 ` [PATCH V2 " Geoff Levand
2014-10-23 23:10 ` [PATCH 04/10] arm64: Add EL2 switch to soft_restart Geoff Levand
2014-10-24 10:57 ` Mark Rutland
2014-10-31 23:47 ` Geoff Levand
2014-10-23 23:10 ` [PATCH 08/10] arm64/kexec: Add core kexec support Geoff Levand
2014-10-24 10:28 ` Mark Rutland
2014-11-13 2:19 ` Geoff Levand
2014-11-17 16:38 ` Mark Rutland
2014-11-17 20:20 ` Geoff Levand
2014-11-07 11:01 ` Arun Chandran
2014-11-12 21:54 ` Geoff Levand
2014-11-13 9:52 ` Arun Chandran
2014-11-17 3:52 ` Dave Young
2014-10-23 23:10 ` [PATCH 06/10] arm64: Update booting.txt to reserved-memory nodes Geoff Levand
2014-10-24 10:54 ` Mark Rutland
2014-10-24 11:04 ` Grant Likely
2014-10-24 12:18 ` Mark Rutland
2014-10-24 13:54 ` Grant Likely
2014-10-24 14:10 ` Mark Rutland
2014-10-24 14:47 ` Grant Likely
2014-10-23 23:10 ` [PATCH 10/10] arm64/kexec: Add pr_devel output Geoff Levand
2014-10-23 23:10 ` [PATCH 09/10] arm64/kexec: Enable kexec in the arm64 defconfig Geoff Levand
2014-10-24 10:31 ` Mark Rutland
2014-10-31 23:50 ` Geoff Levand
2014-11-03 20:05 ` Mark Rutland
2014-11-04 1:49 ` Geoff Levand
2014-10-31 7:52 ` [PATCH 00/10] arm64 kexec kernel patches V5 Dave Young
2014-10-31 23:25 ` Geoff Levand
2014-11-06 2:01 ` Dave Young
2014-11-13 8:37 ` Dave Young
2014-11-13 23:50 ` Geoff Levand
2014-11-17 3:49 ` Dave Young
2014-11-03 19:46 ` Mark Rutland
2014-11-06 1:56 ` Dave Young
2014-11-06 15:08 ` Mark Rutland
2014-11-07 0:41 ` Grant Likely
2014-11-07 10:16 ` Mark Rutland [this message]
2014-11-07 10:41 ` Ard Biesheuvel
2014-11-07 10:45 ` Ard Biesheuvel
2014-11-07 10:46 ` Ard Biesheuvel
2014-11-07 11:35 ` Mark Rutland
2014-11-07 11:42 ` Ard Biesheuvel
2014-11-07 22:34 ` Grant Likely
2014-11-06 12:16 ` Arun Chandran
2014-11-06 15:28 ` Mark Rutland
2014-11-06 16:13 ` Arun Chandran
2014-11-06 18:25 ` Geoff Levand
2014-11-07 6:26 ` Arun Chandran
2014-11-06 18:39 ` Mark Rutland
2014-11-07 6:36 ` Arun Chandran
2014-11-10 7:17 ` Dave Young
2014-11-10 8:35 ` Arun Chandran
2014-11-10 9:24 ` Dave Young
2014-11-12 9:56 ` Dave Young
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