Re: [PATCH v3 1/12] Create a powerpc update_devicetree interface
On 04/22/2013 07:15 PM, Benjamin Herrenschmidt wrote:
On Mon, 2013-04-22 at 13:30 -0500, Nathan Fontenot wrote:
This patch exposes a method for updating the device tree via
ppc_md.update_devicetree that takes a single 32-bit value as a parameter.
For pseries platforms this is the existing pseries_devicetree_update routine
which is updated to take the new parameter which is a scope value
to indicate the the reason for making the rtas calls. This parameter is
required by the ibm,update-nodes/ibm,update-properties RTAS calls, and
the appropriate value is contained within the RTAS event for PRRN
notifications. In pseries_devicetree_update() it was previously
hard-coded to 1, the scope value for partition migration.
I think that's too much abstraction (see below)
Also you add this helper:
Index: powerpc/arch/powerpc/kernel/rtas.c
===
--- powerpc.orig/arch/powerpc/kernel/rtas.c 2013-03-08 19:23:06.0
-0600
+++ powerpc/arch/powerpc/kernel/rtas.c 2013-04-17 13:02:29.0
-0500
@@ -1085,3 +1085,13 @@
timebase = 0;
arch_spin_unlock(timebase_lock);
}
+
+int update_devicetree(s32 scope)
+{
+int rc = 0;
+
+if (ppc_md.update_devicetree)
+rc = ppc_md.update_devicetree(scope);
+
+return rc;
+}
But then don't use it afaik (you call directly ppc_md.update_... from
prrn_work_fn().
In the end, the caller (PRRN stuff), while in rtasd, is really pseries
specific and the resulting update_device_tree() as well, so I don't
think we need the ppc_md. hook in the middle with that oddball scope
parameter which is not defined outside of pseries specific areas.
In this case, it might be better to make sure the PRRN related stuff in
rtasd is inside an ifdef CONFIG_PPC_PSERIES and have it call directly
into pseries_update_devicetree().
It makes the code somewhat easier to follow and I doubt anybody else
will ever use that specific hook, at least not in its current form. If
we need an abstraction later, we can add one then.
ok, good. I was not crazy about using ppc_md to do this and if you're fine
with putting the pseries specific stuff in ifdef CONFIG_PPC_PSERIES I'll
update the code to do that.
Question concerning rtas code. There is quite a bit of pseries specific
pieces in the general powerpc/kernel directory. Has there been, or should
there be, any effort to move that to the pseries directory?
-Nathan
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Re: [PATCH v3 1/12] Create a powerpc update_devicetree interface
On Tue, 2013-04-23 at 13:46 -0500, Nathan Fontenot wrote: ok, good. I was not crazy about using ppc_md to do this and if you're fine with putting the pseries specific stuff in ifdef CONFIG_PPC_PSERIES I'll update the code to do that. Question concerning rtas code. There is quite a bit of pseries specific pieces in the general powerpc/kernel directory. Has there been, or should there be, any effort to move that to the pseries directory? It's a good question ... it's shared in part with CHRP, it might make sense to split it but only if the split can be done cleanly, which I haven't looked into. Cheers, Ben. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH v3 1/12] Create a powerpc update_devicetree interface
On Mon, 2013-04-22 at 13:30 -0500, Nathan Fontenot wrote:
This patch exposes a method for updating the device tree via
ppc_md.update_devicetree that takes a single 32-bit value as a parameter.
For pseries platforms this is the existing pseries_devicetree_update routine
which is updated to take the new parameter which is a scope value
to indicate the the reason for making the rtas calls. This parameter is
required by the ibm,update-nodes/ibm,update-properties RTAS calls, and
the appropriate value is contained within the RTAS event for PRRN
notifications. In pseries_devicetree_update() it was previously
hard-coded to 1, the scope value for partition migration.
I think that's too much abstraction (see below)
Also you add this helper:
Index: powerpc/arch/powerpc/kernel/rtas.c
===
--- powerpc.orig/arch/powerpc/kernel/rtas.c 2013-03-08 19:23:06.0
-0600
+++ powerpc/arch/powerpc/kernel/rtas.c2013-04-17 13:02:29.0
-0500
@@ -1085,3 +1085,13 @@
timebase = 0;
arch_spin_unlock(timebase_lock);
}
+
+int update_devicetree(s32 scope)
+{
+ int rc = 0;
+
+ if (ppc_md.update_devicetree)
+ rc = ppc_md.update_devicetree(scope);
+
+ return rc;
+}
But then don't use it afaik (you call directly ppc_md.update_... from
prrn_work_fn().
In the end, the caller (PRRN stuff), while in rtasd, is really pseries
specific and the resulting update_device_tree() as well, so I don't
think we need the ppc_md. hook in the middle with that oddball scope
parameter which is not defined outside of pseries specific areas.
In this case, it might be better to make sure the PRRN related stuff in
rtasd is inside an ifdef CONFIG_PPC_PSERIES and have it call directly
into pseries_update_devicetree().
It makes the code somewhat easier to follow and I doubt anybody else
will ever use that specific hook, at least not in its current form. If
we need an abstraction later, we can add one then.
Cheers,
Ben.
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