<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/powerpc/kernel/prom_init.c, branch v4.2.7</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>PCI: Remove unnecessary #includes of &lt;asm/pci.h&gt;</title>
<updated>2015-06-08T12:56:09+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2015-06-04T21:37:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=633adc711de0bcb6d6e1c071302880e0c8c05d57'/>
<id>633adc711de0bcb6d6e1c071302880e0c8c05d57</id>
<content type='text'>
In include/linux/pci.h, we already #include &lt;asm/pci.h&gt;, so we don't need
to include &lt;asm/pci.h&gt; directly.

Remove the unnecessary includes.  All the files here already include
&lt;linux/pci.h&gt;.

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Simon Horman &lt;horms+renesas@verge.net.au&gt;	# sh
Acked-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In include/linux/pci.h, we already #include &lt;asm/pci.h&gt;, so we don't need
to include &lt;asm/pci.h&gt; directly.

Remove the unnecessary includes.  All the files here already include
&lt;linux/pci.h&gt;.

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Simon Horman &lt;horms+renesas@verge.net.au&gt;	# sh
Acked-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Reword the "returning from prom_init" message</title>
<updated>2015-04-10T10:02:48+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2015-03-30T06:38:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7e862d7e7d118e3becc5b495af10ca076f087180'/>
<id>7e862d7e7d118e3becc5b495af10ca076f087180</id>
<content type='text'>
We get way too many bug reports that say "the kernel is hung in
prom_init", which stems from the fact that the last piece of output
people see is "returning from prom_init".

The kernel is almost never hung in prom_init(), it's just that it's
crashed somewhere after prom_init() but prior to the console coming up.

The existing message should give a clue to that, ie. "returning from"
indicates that prom_init() has finished, but it doesn't seem to work.
Let's try something different.

This prints:

  Quiescing Open Firmware ...
  Booting Linux via __start() ...

Which hopefully makes it clear that prom_init() is not the problem, and
although __start() probably isn't either, it's at least the right place
to begin looking.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Wistfully-Acked-by: Jeremy Kerr &lt;jk@ozlabs.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We get way too many bug reports that say "the kernel is hung in
prom_init", which stems from the fact that the last piece of output
people see is "returning from prom_init".

The kernel is almost never hung in prom_init(), it's just that it's
crashed somewhere after prom_init() but prior to the console coming up.

The existing message should give a clue to that, ie. "returning from"
indicates that prom_init() has finished, but it doesn't seem to work.
Let's try something different.

This prints:

  Quiescing Open Firmware ...
  Booting Linux via __start() ...

Which hopefully makes it clear that prom_init() is not the problem, and
although __start() probably isn't either, it's at least the right place
to begin looking.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Wistfully-Acked-by: Jeremy Kerr &lt;jk@ozlabs.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/powernv: Remove OPAL v1 takeover</title>
<updated>2014-06-25T03:10:47+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2014-06-24T07:17:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e2500be2b801f4e95d6a1efbc50af3bf14eeb940'/>
<id>e2500be2b801f4e95d6a1efbc50af3bf14eeb940</id>
<content type='text'>
In commit 27f4488872d9 "Add OPAL takeover from PowerVM" we added support
for "takeover" on OPAL v1 machines.

This was a mode of operation where we would boot under pHyp, and query
for the presence of OPAL. If detected we would then do a special
sequence to take over the machine, and the kernel would end up running
in hypervisor mode.

OPAL v1 was never a supported product, and was never shipped outside
IBM. As far as we know no one is still using it.

Newer versions of OPAL do not use the takeover mechanism. Although the
query for OPAL should be harmless on machines with newer OPAL, we have
seen a machine where it causes a crash in Open Firmware.

The code in early_init_devtree() to copy boot_command_line into cmd_line
was added in commit 817c21ad9a1f "Get kernel command line accross OPAL
takeover", and AFAIK is only used by takeover, so should also be
removed.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In commit 27f4488872d9 "Add OPAL takeover from PowerVM" we added support
for "takeover" on OPAL v1 machines.

This was a mode of operation where we would boot under pHyp, and query
for the presence of OPAL. If detected we would then do a special
sequence to take over the machine, and the kernel would end up running
in hypervisor mode.

OPAL v1 was never a supported product, and was never shipped outside
IBM. As far as we know no one is still using it.

Newer versions of OPAL do not use the takeover mechanism. Although the
query for OPAL should be harmless on machines with newer OPAL, we have
seen a machine where it causes a crash in Open Firmware.

The code in early_init_devtree() to copy boot_command_line into cmd_line
was added in commit 817c21ad9a1f "Get kernel command line accross OPAL
takeover", and AFAIK is only used by takeover, so should also be
removed.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Check return value of instance-to-package OF call</title>
<updated>2014-01-12T22:49:17+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2014-01-12T22:49:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=10348f5976830e5d8f74e8abb04a9a057a5e8478'/>
<id>10348f5976830e5d8f74e8abb04a9a057a5e8478</id>
<content type='text'>
On PA-Semi firmware, the instance-to-package callback doesn't seem
to be implemented. We didn't check for error, however, thus
subsequently passed the -1 value returned into stdout_node to
thins like prom_getprop etc...

Thus caused the firmware to load values around 0 (physical) internally
as node structures. It somewhat "worked" as long as we had a NULL in the
right place (address 8) at the beginning of the kernel, we didn't "see"
the bug. But commit 5c0484e25ec03243d4c2f2d4416d4a13efc77f6a
"powerpc: Endian safe trampoline" changed the kernel entry point causing
that old bug to now cause a crash early during boot.

This fixes booting on PA-Semi board by properly checking the return
value from instance-to-package.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Tested-by: Olof Johansson &lt;olof@lixom.net&gt;
---
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On PA-Semi firmware, the instance-to-package callback doesn't seem
to be implemented. We didn't check for error, however, thus
subsequently passed the -1 value returned into stdout_node to
thins like prom_getprop etc...

Thus caused the firmware to load values around 0 (physical) internally
as node structures. It somewhat "worked" as long as we had a NULL in the
right place (address 8) at the beginning of the kernel, we didn't "see"
the bug. But commit 5c0484e25ec03243d4c2f2d4416d4a13efc77f6a
"powerpc: Endian safe trampoline" changed the kernel entry point causing
that old bug to now cause a crash early during boot.

This fixes booting on PA-Semi board by properly checking the return
value from instance-to-package.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Tested-by: Olof Johansson &lt;olof@lixom.net&gt;
---
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: prom_init exception when updating core value</title>
<updated>2013-10-11T05:53:16+00:00</updated>
<author>
<name>Laurent Dufour</name>
<email>ldufour@linux.vnet.ibm.com</email>
</author>
<published>2013-09-17T09:52:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dbd0c5d5296f291a5c3affee4fbdde254632ffca'/>
<id>dbd0c5d5296f291a5c3affee4fbdde254632ffca</id>
<content type='text'>
Since the CPU is generating an exception when accessing unaligned word, and
as this exception is not yet handled when running prom_init, data should be
copied from the architecture vector byte per byte.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since the CPU is generating an exception when accessing unaligned word, and
as this exception is not yet handled when running prom_init, data should be
copied from the architecture vector byte per byte.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Do not start secondaries in Open Firmware</title>
<updated>2013-09-25T04:19:00+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2013-09-25T04:02:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dbe78b40118636f2d5d276144239dd4bfd5f04f9'/>
<id>dbe78b40118636f2d5d276144239dd4bfd5f04f9</id>
<content type='text'>
Starting secondary CPUs early on from Open Firmware and placing them
in a holding spin loop slows down the boot process significantly under
some hypervisors such as KVM.

This is also unnecessary when RTAS supports querying the CPU state

So let's not do it.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Starting secondary CPUs early on from Open Firmware and placing them
in a holding spin loop slows down the boot process significantly under
some hypervisors such as KVM.

This is also unnecessary when RTAS supports querying the CPU state

So let's not do it.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix section mismatch warning for prom_rtas_call</title>
<updated>2013-09-11T01:39:38+00:00</updated>
<author>
<name>Vladimir Murzin</name>
<email>murzin.v@gmail.com</email>
</author>
<published>2013-09-10T16:42:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=620e5050827008ab207a8dfcc44cb79f07f1942c'/>
<id>620e5050827008ab207a8dfcc44cb79f07f1942c</id>
<content type='text'>
While cross-building for PPC64 I've got

WARNING: vmlinux.o(.text.unlikely+0x1ba): Section mismatch in
reference from the function .prom_rtas_call() to the variable
.init.data:dt_string_start The function .prom_rtas_call() references
the variable __initdata dt_string_start.  This is often because
.prom_rtas_call lacks a __initdata annotation or the annotation of
dt_string_start is wrong.

WARNING: vmlinux.o(.meminit.text+0xeb0): Section mismatch in reference
from the function .free_area_init_core.isra.47() to the function
.init.text:.set_pageblock_order() The function __meminit
.free_area_init_core.isra.47() references a function __init
.set_pageblock_order().  If .set_pageblock_order is only used by
.free_area_init_core.isra.47 then annotate .set_pageblock_order with a
matching annotation.

Fix it by proper annotation of prom_rtas_call.

Signed-off-by: Vladimir Murzin &lt;murzin.v@gmail.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While cross-building for PPC64 I've got

WARNING: vmlinux.o(.text.unlikely+0x1ba): Section mismatch in
reference from the function .prom_rtas_call() to the variable
.init.data:dt_string_start The function .prom_rtas_call() references
the variable __initdata dt_string_start.  This is often because
.prom_rtas_call lacks a __initdata annotation or the annotation of
dt_string_start is wrong.

WARNING: vmlinux.o(.meminit.text+0xeb0): Section mismatch in reference
from the function .free_area_init_core.isra.47() to the function
.init.text:.set_pageblock_order() The function __meminit
.free_area_init_core.isra.47() references a function __init
.set_pageblock_order().  If .set_pageblock_order is only used by
.free_area_init_core.isra.47 then annotate .set_pageblock_order with a
matching annotation.

Fix it by proper annotation of prom_rtas_call.

Signed-off-by: Vladimir Murzin &lt;murzin.v@gmail.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Make prom_init.c endian safe</title>
<updated>2013-08-14T05:33:28+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2013-08-06T16:01:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=493adffcb43ffd9f8f2d5485603574502fd9e01d'/>
<id>493adffcb43ffd9f8f2d5485603574502fd9e01d</id>
<content type='text'>
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pmac: Early debug output on screen on 64-bit macs</title>
<updated>2013-08-14T04:57:40+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2013-07-25T02:12:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7191b615759ec10cab9eea43be5ecc42cda82364'/>
<id>7191b615759ec10cab9eea43be5ecc42cda82364</id>
<content type='text'>
We have a bunch of CONFIG_PPC_EARLY_DEBUG_* options that are intended
for bringup/debug only. They hard wire a machine specific udbg backend
very early on (before we even probe the platform), and use whatever
tricks are available on each machine/cpu to be able to get some kind
of output out there early on.

So far, on powermac with no serial ports, we have CONFIG_PPC_EARLY_DEBUG_BOOTX
to use the low-level btext engine on the screen, but it doesn't do much, at
least on 64-bit. It only really gets enabled after the platform has been
probed and the MMU enabled.

This adds a way to enable it much earlier. From prom_init.c (while still
running with Open Firmware), we grab the screen details and set things up
using the physical address of the frame buffer.

Then btext itself uses the "rm_ci" feature of the 970 processor (Real
Mode Cache Inhibited) to access it while in real mode.

We need to do a little bit of reorg of the btext code to inline things
better, in order to limit how much we touch memory while in this mode as
the consequences might be ... interesting.

This successfully allowed me to debug problems early on with the G5
(related to gold being broken vs. ppc64 kernels).

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We have a bunch of CONFIG_PPC_EARLY_DEBUG_* options that are intended
for bringup/debug only. They hard wire a machine specific udbg backend
very early on (before we even probe the platform), and use whatever
tricks are available on each machine/cpu to be able to get some kind
of output out there early on.

So far, on powermac with no serial ports, we have CONFIG_PPC_EARLY_DEBUG_BOOTX
to use the low-level btext engine on the screen, but it doesn't do much, at
least on 64-bit. It only really gets enabled after the platform has been
probed and the MMU enabled.

This adds a way to enable it much earlier. From prom_init.c (while still
running with Open Firmware), we grab the screen details and set things up
using the physical address of the frame buffer.

Then btext itself uses the "rm_ci" feature of the 970 processor (Real
Mode Cache Inhibited) to access it while in real mode.

We need to do a little bit of reorg of the btext code to inline things
better, in order to limit how much we touch memory while in this mode as
the consequences might be ... interesting.

This successfully allowed me to debug problems early on with the G5
(related to gold being broken vs. ppc64 kernels).

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Add second POWER8 PVR entry</title>
<updated>2013-07-24T04:18:43+00:00</updated>
<author>
<name>Michael Neuling</name>
<email>mikey@neuling.org</email>
</author>
<published>2013-07-18T01:31:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=33959f88fce9b8d3346d8000b3425814cbc6d6c0'/>
<id>33959f88fce9b8d3346d8000b3425814cbc6d6c0</id>
<content type='text'>
POWER8 comes with two different PVRs.  This patch enables the additional
PVR in the cputable.

The existing entry (PVR=0x4b) is renamed to POWER8E and the new entry
(PVR=0x4d) is given POWER8.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
POWER8 comes with two different PVRs.  This patch enables the additional
PVR in the cputable.

The existing entry (PVR=0x4b) is renamed to POWER8E and the new entry
(PVR=0x4d) is given POWER8.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
