From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Rob Herring <robherring2@gmail.com>,
Gavin Shan <gwshan@linux.vnet.ibm.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Bjorn Helgaas <bhelgaas@google.com>,
Grant Likely <grant.likely@linaro.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: Re: [PATCH v4 19/21] drivers/of: Support adding sub-tree
Date: Fri, 15 May 2015 09:25:53 +1000 [thread overview]
Message-ID: <1431645953.4160.82.camel@kernel.crashing.org> (raw)
In-Reply-To: <A748C569-24CF-41B9-BA91-822A67132DA9@antoniou-consulting.com>
On Thu, 2015-05-14 at 14:02 +0300, Pantelis Antoniou wrote:
> Hi Ben,
>
> > On May 14, 2015, at 10:47 , Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> >
>
> [snip]
>
> So I spend some time thinking about your use case and I think it boils down
> to this:
>
> I have a live tree in the firmware, I have made changes and I need to reflect
> those changes to the live tree in the kernel.
>
> Sounds like ‘how do I generate a patch for getting those two in sync'. No?
More or less.
> I can see where this might be useful for others as all.
>
> I think we really need to create a liblivedt like we have libfdt since
> we have a number of projects going about using/manipulating DT at runtime.
>
> 1. The linux kernel, with it’s own live tree implementation.
> 2. The device tree compiler (it has a live tree) custom implemented.
> 3. Your weird and wonderful (or wacky) firmware.
> 4. u-boot does use DT now, but it does with libfdt. I believe this is suboptimal.
> 5. barebox does DT as well.
>
> Most of what we want to do with DT can be abstracted in a library I think that
> all of those projects can use.
>
> What are your thoughts?
Well, we have at least two implementations, the kernel one and the one
in our OPAL firmware:
https://github.com/open-power/skiboot/blob/master/include/device.h
https://github.com/open-power/skiboot/blob/master/core/device.c
The latter uses some nice Rusty tricks (tm) for multiple argument
functions.
It would make sense to do a library somewhere yes. However, I need to
cut my firmware API pretty much today so I think for now I'll stick
to something Ad-Hoc for the PCI hotplug code that just passes the
bit of FDT with the new devices and leave the "grand project" of live
sync of the tree for later.
There are other implementations of live DT in various Open Firmware
variants out there, most are in Forth which I suggest you don't bother
with unless you enjoy pain, but I think at least one of these is
actually in C.
Cheers,
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
Gavin Shan <gwshan@linux.vnet.ibm.com>,
Grant Likely <grant.likely@linaro.org>,
Rob Herring <robherring2@gmail.com>,
Bjorn Helgaas <bhelgaas@google.com>,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>
Subject: Re: [PATCH v4 19/21] drivers/of: Support adding sub-tree
Date: Fri, 15 May 2015 09:25:53 +1000 [thread overview]
Message-ID: <1431645953.4160.82.camel@kernel.crashing.org> (raw)
In-Reply-To: <A748C569-24CF-41B9-BA91-822A67132DA9@antoniou-consulting.com>
On Thu, 2015-05-14 at 14:02 +0300, Pantelis Antoniou wrote:
> Hi Ben,
>
> > On May 14, 2015, at 10:47 , Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> >
>
> [snip]
>
> So I spend some time thinking about your use case and I think it boils down
> to this:
>
> I have a live tree in the firmware, I have made changes and I need to reflect
> those changes to the live tree in the kernel.
>
> Sounds like ‘how do I generate a patch for getting those two in sync'. No?
More or less.
> I can see where this might be useful for others as all.
>
> I think we really need to create a liblivedt like we have libfdt since
> we have a number of projects going about using/manipulating DT at runtime.
>
> 1. The linux kernel, with it’s own live tree implementation.
> 2. The device tree compiler (it has a live tree) custom implemented.
> 3. Your weird and wonderful (or wacky) firmware.
> 4. u-boot does use DT now, but it does with libfdt. I believe this is suboptimal.
> 5. barebox does DT as well.
>
> Most of what we want to do with DT can be abstracted in a library I think that
> all of those projects can use.
>
> What are your thoughts?
Well, we have at least two implementations, the kernel one and the one
in our OPAL firmware:
https://github.com/open-power/skiboot/blob/master/include/device.h
https://github.com/open-power/skiboot/blob/master/core/device.c
The latter uses some nice Rusty tricks (tm) for multiple argument
functions.
It would make sense to do a library somewhere yes. However, I need to
cut my firmware API pretty much today so I think for now I'll stick
to something Ad-Hoc for the PCI hotplug code that just passes the
bit of FDT with the new devices and leave the "grand project" of live
sync of the tree for later.
There are other implementations of live DT in various Open Firmware
variants out there, most are in Forth which I suggest you don't bother
with unless you enjoy pain, but I think at least one of these is
actually in C.
Cheers,
Ben.
next prev parent reply other threads:[~2015-05-14 23:25 UTC|newest]
Thread overview: 184+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-01 6:02 [PATCH v4 00/21] PowerPC/PowerNV: PCI Slot Management Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 01/21] pci: Add pcibios_setup_bridge() Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-07 22:12 ` Bjorn Helgaas
2015-05-07 22:12 ` Bjorn Helgaas
2015-05-11 1:59 ` Gavin Shan
2015-05-11 1:59 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 02/21] powerpc/powernv: Enable M64 on P7IOC Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 0:18 ` Alexey Kardashevskiy
2015-05-09 0:18 ` Alexey Kardashevskiy
2015-05-11 4:37 ` Gavin Shan
2015-05-11 4:37 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 03/21] powerpc/powernv: M64 support improvement Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 10:24 ` Alexey Kardashevskiy
2015-05-09 10:24 ` Alexey Kardashevskiy
2015-05-11 4:47 ` Gavin Shan
2015-05-11 4:47 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 04/21] powerpc/powernv: Improve IO and M32 mapping Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 10:53 ` Alexey Kardashevskiy
2015-05-09 10:53 ` Alexey Kardashevskiy
2015-05-11 4:52 ` Gavin Shan
2015-05-11 4:52 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 05/21] powerpc/powernv: Improve DMA32 segment assignment Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 06/21] powerpc/powernv: Create PEs dynamically Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 11:43 ` Alexey Kardashevskiy
2015-05-09 11:43 ` Alexey Kardashevskiy
2015-05-11 4:55 ` Gavin Shan
2015-05-11 4:55 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 07/21] powerpc/powernv: Release " Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 12:43 ` Alexey Kardashevskiy
2015-05-09 12:43 ` Alexey Kardashevskiy
2015-05-11 6:25 ` Gavin Shan
2015-05-11 6:25 ` Gavin Shan
2015-05-11 7:02 ` Alexey Kardashevskiy
2015-05-11 7:02 ` Alexey Kardashevskiy
2015-05-12 0:03 ` Gavin Shan
2015-05-12 0:03 ` Gavin Shan
2015-05-12 0:53 ` Alexey Kardashevskiy
2015-05-12 0:53 ` Alexey Kardashevskiy
2015-05-12 1:25 ` Gavin Shan
2015-05-12 1:25 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 08/21] powerpc/powernv: Drop pnv_ioda_setup_dev_PE() Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 12:45 ` Alexey Kardashevskiy
2015-05-09 12:45 ` Alexey Kardashevskiy
2015-05-01 6:02 ` [PATCH v4 09/21] powerpc/powernv: Use PCI slot reset infrastructure Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 13:41 ` Alexey Kardashevskiy
2015-05-09 13:41 ` Alexey Kardashevskiy
2015-05-11 6:45 ` Gavin Shan
2015-05-11 6:45 ` Gavin Shan
2015-05-11 7:16 ` Alexey Kardashevskiy
2015-05-11 7:16 ` Alexey Kardashevskiy
2015-05-01 6:02 ` [PATCH v4 10/21] powerpc/powernv: Fundamental reset for PCI bus reset Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-09 14:12 ` Alexey Kardashevskiy
2015-05-09 14:12 ` Alexey Kardashevskiy
2015-05-11 6:47 ` Gavin Shan
2015-05-11 6:47 ` Gavin Shan
2015-05-11 7:17 ` Alexey Kardashevskiy
2015-05-11 7:17 ` Alexey Kardashevskiy
2015-05-12 0:04 ` Gavin Shan
2015-05-12 0:04 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 11/21] powerpc/pci: Don't scan empty slot Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-01 6:02 ` [PATCH v4 12/21] powerpc/pci: Move pcibios_find_pci_bus() around Gavin Shan
2015-05-01 6:02 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 13/21] powerpc/powernv: Introduce pnv_pci_poll() Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-09 14:30 ` Alexey Kardashevskiy
2015-05-09 14:30 ` Alexey Kardashevskiy
2015-05-11 7:19 ` Gavin Shan
2015-05-11 7:19 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 14/21] powerpc/powernv: Functions to get/reset PCI slot status Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-09 14:44 ` Alexey Kardashevskiy
2015-05-09 14:44 ` Alexey Kardashevskiy
2015-05-01 6:03 ` [PATCH v4 15/21] powerpc/pci: Delay creating pci_dn Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-09 14:55 ` Alexey Kardashevskiy
2015-05-09 14:55 ` Alexey Kardashevskiy
2015-05-11 7:21 ` Gavin Shan
2015-05-11 7:21 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 16/21] powerpc/pci: Create eeh_dev while " Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-09 15:08 ` Alexey Kardashevskiy
2015-05-09 15:08 ` Alexey Kardashevskiy
2015-05-11 7:24 ` Gavin Shan
2015-05-11 7:24 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 17/21] powerpc/pci: Export traverse_pci_device_nodes() Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 18/21] powerpc/pci: Update bridge windows on PCI plugging Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 19/21] drivers/of: Support adding sub-tree Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-01 12:54 ` Rob Herring
2015-05-01 12:54 ` Rob Herring
2015-05-01 15:22 ` Benjamin Herrenschmidt
2015-05-01 15:22 ` Benjamin Herrenschmidt
2015-05-01 18:46 ` Rob Herring
2015-05-01 18:46 ` Rob Herring
2015-05-01 22:57 ` Benjamin Herrenschmidt
2015-05-01 22:57 ` Benjamin Herrenschmidt
2015-05-01 23:29 ` Benjamin Herrenschmidt
2015-05-01 23:29 ` Benjamin Herrenschmidt
2015-05-02 2:48 ` Benjamin Herrenschmidt
2015-05-02 2:48 ` Benjamin Herrenschmidt
2015-05-04 1:30 ` Gavin Shan
2015-05-04 1:30 ` Gavin Shan
2015-05-04 4:51 ` Benjamin Herrenschmidt
2015-05-04 4:51 ` Benjamin Herrenschmidt
2015-05-04 0:23 ` Gavin Shan
2015-05-04 0:23 ` Gavin Shan
[not found] ` <1430521038.7979.70.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2015-05-04 16:41 ` Pantelis Antoniou
2015-05-04 16:41 ` Pantelis Antoniou
2015-05-04 16:41 ` Pantelis Antoniou
2015-05-04 21:14 ` Benjamin Herrenschmidt
2015-05-04 21:14 ` Benjamin Herrenschmidt
2015-05-13 23:35 ` Benjamin Herrenschmidt
2015-05-13 23:35 ` Benjamin Herrenschmidt
[not found] ` <1431560124.20218.91.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2015-05-14 0:18 ` Rob Herring
2015-05-14 0:18 ` Rob Herring
2015-05-14 0:18 ` Rob Herring
[not found] ` <CAL_JsqKqTa5eg3eOqx3bkeNdO_920WwDiRbQaxwWLEWpCypFmA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-05-14 0:54 ` Benjamin Herrenschmidt
2015-05-14 0:54 ` Benjamin Herrenschmidt
2015-05-14 0:54 ` Benjamin Herrenschmidt
2015-05-14 6:23 ` Pantelis Antoniou
2015-05-14 6:23 ` Pantelis Antoniou
2015-05-14 6:46 ` Benjamin Herrenschmidt
2015-05-14 6:46 ` Benjamin Herrenschmidt
2015-05-14 7:04 ` Pantelis Antoniou
2015-05-14 7:04 ` Pantelis Antoniou
[not found] ` <3988EABE-3DE9-4E1C-9778-22E35138E359-wVdstyuyKrO8r51toPun2/C9HSW9iNxf@public.gmane.org>
2015-05-14 7:14 ` Benjamin Herrenschmidt
2015-05-14 7:14 ` Benjamin Herrenschmidt
2015-05-14 7:14 ` Benjamin Herrenschmidt
2015-05-14 7:19 ` Pantelis Antoniou
2015-05-14 7:19 ` Pantelis Antoniou
2015-05-14 7:19 ` Pantelis Antoniou
[not found] ` <75F026CA-5AC1-4106-B2F0-AB0D006DEF5A-wVdstyuyKrO8r51toPun2/C9HSW9iNxf@public.gmane.org>
2015-05-14 7:25 ` Benjamin Herrenschmidt
2015-05-14 7:25 ` Benjamin Herrenschmidt
2015-05-14 7:25 ` Benjamin Herrenschmidt
2015-05-14 7:29 ` Benjamin Herrenschmidt
2015-05-14 7:29 ` Benjamin Herrenschmidt
[not found] ` <1431588358.4160.42.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2015-05-14 7:34 ` Pantelis Antoniou
2015-05-14 7:34 ` Pantelis Antoniou
2015-05-14 7:34 ` Pantelis Antoniou
[not found] ` <D7FC0542-DD1A-428F-8E75-81620C6D83DC-wVdstyuyKrO8r51toPun2/C9HSW9iNxf@public.gmane.org>
2015-05-14 7:47 ` Benjamin Herrenschmidt
2015-05-14 7:47 ` Benjamin Herrenschmidt
2015-05-14 7:47 ` Benjamin Herrenschmidt
2015-05-14 11:02 ` Pantelis Antoniou
2015-05-14 11:02 ` Pantelis Antoniou
2015-05-14 11:02 ` Pantelis Antoniou
2015-05-14 23:25 ` Benjamin Herrenschmidt [this message]
2015-05-14 23:25 ` Benjamin Herrenschmidt
[not found] ` <1431564871.4160.8.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2015-06-07 7:54 ` Grant Likely
2015-06-07 7:54 ` Grant Likely
[not found] ` <20150607075422.6ECE9C40A12-WNowdnHR2B42iJbIjFUEsiwD8/FfD2ys@public.gmane.org>
2015-06-08 20:57 ` Benjamin Herrenschmidt
2015-06-08 20:57 ` Benjamin Herrenschmidt
[not found] ` <1433797073.4526.163.camel-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2015-06-08 21:34 ` Grant Likely
2015-06-08 21:34 ` Grant Likely
2015-06-10 6:55 ` Gavin Shan
2015-05-03 23:28 ` Gavin Shan
2015-05-03 23:28 ` Gavin Shan
2015-05-15 1:27 ` Gavin Shan
2015-05-15 1:27 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 20/21] powerpc/powernv: Select OF_DYNAMIC Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-01 6:03 ` [PATCH v4 21/21] pci/hotplug: PowerPC PowerNV PCI hotplug driver Gavin Shan
2015-05-01 6:03 ` Gavin Shan
2015-05-09 15:54 ` Alexey Kardashevskiy
2015-05-09 15:54 ` Alexey Kardashevskiy
2015-05-11 7:38 ` Gavin Shan
2015-05-11 7:38 ` Gavin Shan
2015-05-08 23:59 ` [PATCH v4 00/21] PowerPC/PowerNV: PCI Slot Management Alexey Kardashevskiy
2015-05-08 23:59 ` Alexey Kardashevskiy
2015-05-11 7:40 ` Gavin Shan
2015-05-11 7:40 ` Gavin Shan
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