<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/pci/hotplug/fakephp.c, branch v2.6.32.51</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: update fakephp for bus_id removal</title>
<updated>2009-03-26T23:00:34+00:00</updated>
<author>
<name>Stephen Rothwell</name>
<email>sfr@canb.auug.org.au</email>
</author>
<published>2009-03-26T07:34:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7bb2cb3e90dc49be1cd14956c155451499c857a7'/>
<id>7bb2cb3e90dc49be1cd14956c155451499c857a7</id>
<content type='text'>
Get rid of a new use of bus_id that snuck in.

Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Get rid of a new use of bus_id that snuck in.

Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI Hotplug: rename legacy_fakephp to fakephp</title>
<updated>2009-03-20T21:59:37+00:00</updated>
<author>
<name>Alex Chiang</name>
<email>achiang@hp.com</email>
</author>
<published>2009-03-20T20:56:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8ffd25454738fb9ed76ee18cc0f180fb0b360401'/>
<id>8ffd25454738fb9ed76ee18cc0f180fb0b360401</id>
<content type='text'>
We wanted to replace fakephp wholesale, so rename legacy_fakephp back
to fakephp. Yes, this is a silly commit, but it produces a much easier
patch to read and review.

Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We wanted to replace fakephp wholesale, so rename legacy_fakephp back
to fakephp. Yes, this is a silly commit, but it produces a much easier
patch to read and review.

Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI Hotplug: restore fakephp interface with complete reimplementation</title>
<updated>2009-03-20T21:59:25+00:00</updated>
<author>
<name>Trent Piepho</name>
<email>xyzzy@speakeasy.org</email>
</author>
<published>2009-03-20T20:56:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=83dbf66f04b96e65c6c18436c16d40f9cf8630aa'/>
<id>83dbf66f04b96e65c6c18436c16d40f9cf8630aa</id>
<content type='text'>
A complete re-implementation of fakephp is necessary if it is to
present its former interface (pre-2.6.27, when it broke). The
reason is that PCI hotplug drivers call pci_hp_register(), which
enforces the rule that only one /sys/bus/pci/slots/ file may be
created per physical slot.

The change breaks the old fakephp's assumption that it could
create a file per function. So we re-implement fakephp to avoid
using the standard PCI hotplug API so that we can restore the old
fakephp user interface.

It puts entries in /sys/bus/pci/slots with the names of all PCI
devices/functions, exactly symmetrical to what is shown in
/sys/bus/pci/devices. Each slots/ entry has a "power" attribute,
which works the same way as the fakephp driver's power attribute
has worked.

There are a few improvements over old fakephp, which couldn't handle
PCI devices being added or removed via a means outside of
fakephp's knowledge.  If a device was added another way, old fakephp
didn't notice and didn't create the fake slot for it.  If a
device was removed another way, old fakephp didn't delete the fake
slot for it (and accessing the stale slot caused an oops).

The new implementation overcomes these limitations. As a
consequence, removing a bridge with other devices behind it now
works as well, which is something else old fakephp couldn't do
previously.

This duplicates a tiny bit of the code in the PCI core that does
this same function.  Re-using that code ends up being more
complex than duplicating it, and it makes code in the PCI core
more ugly just to support this legacy fakephp interface
compatibility layer.

Reviewed-by: James Cameron &lt;qz@hp.com&gt;
Signed-off-by: Trent Piepho &lt;xyzzy@speakeasy.org&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A complete re-implementation of fakephp is necessary if it is to
present its former interface (pre-2.6.27, when it broke). The
reason is that PCI hotplug drivers call pci_hp_register(), which
enforces the rule that only one /sys/bus/pci/slots/ file may be
created per physical slot.

The change breaks the old fakephp's assumption that it could
create a file per function. So we re-implement fakephp to avoid
using the standard PCI hotplug API so that we can restore the old
fakephp user interface.

It puts entries in /sys/bus/pci/slots with the names of all PCI
devices/functions, exactly symmetrical to what is shown in
/sys/bus/pci/devices. Each slots/ entry has a "power" attribute,
which works the same way as the fakephp driver's power attribute
has worked.

There are a few improvements over old fakephp, which couldn't handle
PCI devices being added or removed via a means outside of
fakephp's knowledge.  If a device was added another way, old fakephp
didn't notice and didn't create the fake slot for it.  If a
device was removed another way, old fakephp didn't delete the fake
slot for it (and accessing the stale slot caused an oops).

The new implementation overcomes these limitations. As a
consequence, removing a bridge with other devices behind it now
works as well, which is something else old fakephp couldn't do
previously.

This duplicates a tiny bit of the code in the PCI core that does
this same function.  Re-using that code ends up being more
complex than duplicating it, and it makes code in the PCI core
more ugly just to support this legacy fakephp interface
compatibility layer.

Reviewed-by: James Cameron &lt;qz@hp.com&gt;
Signed-off-by: Trent Piepho &lt;xyzzy@speakeasy.org&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: Introduce pci_rescan_bus()</title>
<updated>2009-03-20T21:57:44+00:00</updated>
<author>
<name>Alex Chiang</name>
<email>achiang@hp.com</email>
</author>
<published>2009-03-20T20:56:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3ed4fd96b3188406ac5357d9290bcffa08c65cf6'/>
<id>3ed4fd96b3188406ac5357d9290bcffa08c65cf6</id>
<content type='text'>
This API is used by the PCI core to rescan a bus and rediscover
newly added devices.

Over time, it is expected that the various PCI hotplug drivers
will migrate to this interface and away from the old
pci_do_scan_bus() interface.

Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This API is used by the PCI core to rescan a bus and rediscover
newly added devices.

Over time, it is expected that the various PCI hotplug drivers
will migrate to this interface and away from the old
pci_do_scan_bus() interface.

Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI hotplug: fakephp: Allocate PCI resources before adding the device</title>
<updated>2009-01-27T18:53:24+00:00</updated>
<author>
<name>Darrick J. Wong</name>
<email>djwong@us.ibm.com</email>
</author>
<published>2008-11-25T21:51:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=bf4162bcf82ebc3258d6bc0ddd6453132abde72d'/>
<id>bf4162bcf82ebc3258d6bc0ddd6453132abde72d</id>
<content type='text'>
For PCI devices, pci_bus_assign_resources() must be called to set up the
pci_device-&gt;resource array before pci_bus_add_devices() can be called, else
attempts to load drivers results in BAR collision errors where there are none.
This is not done in fakephp, so devices can be "unplugged" but scanning the
parent bus won't bring the devices back due to resource unallocation.  Move the
pci_bus_add_device-calling logic into pci_rescan_bus and preface it with a call
to pci_bus_assign_resources so that we only have to (re)allocate resources once
per bus where a new device is found.

Signed-off-by: Darrick J. Wong &lt;djwong@us.ibm.com&gt;
Acked-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For PCI devices, pci_bus_assign_resources() must be called to set up the
pci_device-&gt;resource array before pci_bus_add_devices() can be called, else
attempts to load drivers results in BAR collision errors where there are none.
This is not done in fakephp, so devices can be "unplugged" but scanning the
parent bus won't bring the devices back due to resource unallocation.  Move the
pci_bus_add_device-calling logic into pci_rescan_bus and preface it with a call
to pci_bus_assign_resources so that we only have to (re)allocate resources once
per bus where a new device is found.

Signed-off-by: Darrick J. Wong &lt;djwong@us.ibm.com&gt;
Acked-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/pci/hotplug: Add missing pci_dev_get</title>
<updated>2009-01-07T19:12:33+00:00</updated>
<author>
<name>Julia Lawall</name>
<email>julia@diku.dk</email>
</author>
<published>2008-11-23T08:08:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4ba7d0f0eb68cf7731ead4ca20e540d0266cfa8e'/>
<id>4ba7d0f0eb68cf7731ead4ca20e540d0266cfa8e</id>
<content type='text'>
pci_get_slot does a pci_dev_get, so pci_dev_put needs to be called in an
error case.

An alterative would be to move the test_and_set_bit before the call to
pci_get_slot.

The problem was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// &lt;smpl&gt;
@@
local idexpression *n;
statement S1,S2;
expression E,E1;
expression *ptr != NULL;
type T,T1;
@@

(
if (!(n = pci_get_slot(...))) S1
|
n = pci_get_slot(...)
)
&lt;... when != pci_dev_put(n)
    when != if (...) { &lt;+... pci_dev_put(n) ...+&gt; }
    when != true !n  || ...
    when != n = (T)E
    when != E = n
if (!n || ...) S2
...&gt;
(
  return \(0\|&lt;+...n...+&gt;\|ptr\);
|
+ pci_dev_put(n);
return ...;
|
pci_dev_put(n);
|
n = (T1)E1
|
E1 = n
)
// &lt;/smpl&gt;

Signed-off-by: Julia Lawall &lt;julia@diku.dk&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
pci_get_slot does a pci_dev_get, so pci_dev_put needs to be called in an
error case.

An alterative would be to move the test_and_set_bit before the call to
pci_get_slot.

The problem was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// &lt;smpl&gt;
@@
local idexpression *n;
statement S1,S2;
expression E,E1;
expression *ptr != NULL;
type T,T1;
@@

(
if (!(n = pci_get_slot(...))) S1
|
n = pci_get_slot(...)
)
&lt;... when != pci_dev_put(n)
    when != if (...) { &lt;+... pci_dev_put(n) ...+&gt; }
    when != true !n  || ...
    when != n = (T)E
    when != E = n
if (!n || ...) S2
...&gt;
(
  return \(0\|&lt;+...n...+&gt;\|ptr\);
|
+ pci_dev_put(n);
return ...;
|
pci_dev_put(n);
|
n = (T1)E1
|
E1 = n
)
// &lt;/smpl&gt;

Signed-off-by: Julia Lawall &lt;julia@diku.dk&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI Hotplug: fakephp: add duplicate slot name debugging</title>
<updated>2008-10-22T23:42:44+00:00</updated>
<author>
<name>Alex Chiang</name>
<email>achiang@hp.com</email>
</author>
<published>2008-10-20T23:42:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0b8b0dca9aad94878adaf4520f3f12bf9813f329'/>
<id>0b8b0dca9aad94878adaf4520f3f12bf9813f329</id>
<content type='text'>
The PCI core now manages slot names on behalf of slot detection
and slot hotplug drivers, including the handling of duplicate
slot names.

We can use the fakephp driver to help test the new functionality.
Add a 'dup_slots' module param to force fakephp to create multiple
slots with the same name. We can then verify that the PCI core
correctly renamed the slots.

	sapphire:/sys/bus/pci/slots # modprobe fakephp dup_slots
	sapphire:/sys/bus/pci/slots # ls
	fake    fake-10  fake-3  fake-5  fake-7  fake-9
	fake-1  fake-2   fake-4  fake-6  fake-8

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The PCI core now manages slot names on behalf of slot detection
and slot hotplug drivers, including the handling of duplicate
slot names.

We can use the fakephp driver to help test the new functionality.
Add a 'dup_slots' module param to force fakephp to create multiple
slots with the same name. We can then verify that the PCI core
correctly renamed the slots.

	sapphire:/sys/bus/pci/slots # modprobe fakephp dup_slots
	sapphire:/sys/bus/pci/slots # ls
	fake    fake-10  fake-3  fake-5  fake-7  fake-9
	fake-1  fake-2   fake-4  fake-6  fake-8

Cc: kristen.c.accardi@intel.com
Cc: matthew@wil.cx
Acked-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: fakephp: remove 'name' parameter</title>
<updated>2008-10-22T23:42:41+00:00</updated>
<author>
<name>Alex Chiang</name>
<email>achiang@hp.com</email>
</author>
<published>2008-10-20T23:41:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=43caae884b5a5e2eacb4879225341cb49700e129'/>
<id>43caae884b5a5e2eacb4879225341cb49700e129</id>
<content type='text'>
Remove 'name' from fakephp's struct dummy_slot, as the PCI core
will now manage our slot name for us.

Cc: jbarnes@virtuousgeek.org
Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove 'name' from fakephp's struct dummy_slot, as the PCI core
will now manage our slot name for us.

Cc: jbarnes@virtuousgeek.org
Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI Hotplug core: add 'name' param pci_hp_register interface</title>
<updated>2008-10-22T23:42:37+00:00</updated>
<author>
<name>Alex Chiang</name>
<email>achiang@hp.com</email>
</author>
<published>2008-10-20T23:40:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1359f2701b96abd9bb69c1273fb995a093b6409a'/>
<id>1359f2701b96abd9bb69c1273fb995a093b6409a</id>
<content type='text'>
Update pci_hp_register() to take a const char *name parameter.

The motivation for this is to clean up the individual hotplug
drivers so that each one does not have to manage its own name.
The PCI core should be the place where we manage the name.

We update the interface and all callsites first, in a
"no functional change" manner, and clean up the drivers later.

Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Reviewed-by: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Update pci_hp_register() to take a const char *name parameter.

The motivation for this is to clean up the individual hotplug
drivers so that each one does not have to manage its own name.
The PCI core should be the place where we manage the name.

We update the interface and all callsites first, in a
"no functional change" manner, and clean up the drivers later.

Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige &lt;kaneshige.kenji@jp.fujitsu.com&gt;
Reviewed-by: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI Hotplug: fakephp: fix deadlock... again</title>
<updated>2008-09-09T18:44:06+00:00</updated>
<author>
<name>Alex Chiang</name>
<email>achiang@hp.com</email>
</author>
<published>2008-09-05T21:05:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=48902025af4da44dbbc0231061e542d6d40e712e'/>
<id>48902025af4da44dbbc0231061e542d6d40e712e</id>
<content type='text'>
Commit fe99740cac117f208707488c03f3789cf4904957 (construct one
fakephp slot per PCI slot) introduced a regression, causing a
deadlock when removing a PCI device.

We also never actually removed the device from the PCI core.

So we:

	- remove the device from the PCI core
	- do not directly call remove_slot() to prevent deadlock

Yu Zhao reported and diagnosed this defect.

Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Acked-by: Yu Zhao &lt;yu.zhao@intel.com&gt;
Cc: Matthew Wilcox &lt;matthew@wil.cx&gt;
Cc: Kristen Carlson Accardi &lt;kristen.c.accardi@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit fe99740cac117f208707488c03f3789cf4904957 (construct one
fakephp slot per PCI slot) introduced a regression, causing a
deadlock when removing a PCI device.

We also never actually removed the device from the PCI core.

So we:

	- remove the device from the PCI core
	- do not directly call remove_slot() to prevent deadlock

Yu Zhao reported and diagnosed this defect.

Signed-off-by: Alex Chiang &lt;achiang@hp.com&gt;
Acked-by: Yu Zhao &lt;yu.zhao@intel.com&gt;
Cc: Matthew Wilcox &lt;matthew@wil.cx&gt;
Cc: Kristen Carlson Accardi &lt;kristen.c.accardi@intel.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
