<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/drivers/pci/bus.c, branch v3.6.1</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: fix undefined reference to 'pci_fixup_final_inited'</title>
<updated>2012-07-16T15:14:49+00:00</updated>
<author>
<name>Myron Stowe</name>
<email>myron.stowe@redhat.com</email>
</author>
<published>2012-07-13T20:29:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=95df8b8708a8b381bf276d83c56f7b4e7de04a71'/>
<id>95df8b8708a8b381bf276d83c56f7b4e7de04a71</id>
<content type='text'>
My "PCI: Integrate 'pci_fixup_final' quirks into hot-plug paths" patch
introduced an undefined reference to 'pci_fixup_final_inited' when
CONFIG_PCI_QUIRKS is not enabled (on x86_64):
  drivers/built-in.o: In function `pci_bus_add_device':
  (.text+0x4f62): undefined reference to `pci_fixup_final_inited'

This patch removes the external reference ending up with a result closer
to what we ultimately want when the boot path issues described in the
original patch are resolved.

References:
  https://lkml.org/lkml/2012/7/9/542    Original, offending, patch
  https://lkml.org/lkml/2012/7/12/338	Randy's catch

Reported-by: Randy Dunlap &lt;rdunlap@xenotime.net&gt;
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@xenotime.net&gt;</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
My "PCI: Integrate 'pci_fixup_final' quirks into hot-plug paths" patch
introduced an undefined reference to 'pci_fixup_final_inited' when
CONFIG_PCI_QUIRKS is not enabled (on x86_64):
  drivers/built-in.o: In function `pci_bus_add_device':
  (.text+0x4f62): undefined reference to `pci_fixup_final_inited'

This patch removes the external reference ending up with a result closer
to what we ultimately want when the boot path issues described in the
original patch are resolved.

References:
  https://lkml.org/lkml/2012/7/9/542    Original, offending, patch
  https://lkml.org/lkml/2012/7/12/338	Randy's catch

Reported-by: Randy Dunlap &lt;rdunlap@xenotime.net&gt;
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@xenotime.net&gt;</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: call final fixups hot-added devices</title>
<updated>2012-07-10T02:56:45+00:00</updated>
<author>
<name>Myron Stowe</name>
<email>myron.stowe@redhat.com</email>
</author>
<published>2012-07-09T21:36:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=735bff10c157fdbba2291e10ca3e28a59c7acc1c'/>
<id>735bff10c157fdbba2291e10ca3e28a59c7acc1c</id>
<content type='text'>
Final fixups are currently applied only at boot-time by
pci_apply_final_quirks(), which is an fs_initcall().  Hot-added devices
don't get these fixups, so they may not be completely initialized.

This patch makes us run final fixups for hot-added devices in
pci_bus_add_device() just before the new device becomes eligible for driver
binding.

This patch keeps the fs_initcall() for devices present at boot because we
do resource assignment between pci_bus_add_device and the fs_initcall(),
and we don't want to break any fixups that depend on that assignment.  This
is a design issue that may be addressed in the future -- any resource
assignment should be done *before* device_add().

[bhelgaas: changelog]
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Final fixups are currently applied only at boot-time by
pci_apply_final_quirks(), which is an fs_initcall().  Hot-added devices
don't get these fixups, so they may not be completely initialized.

This patch makes us run final fixups for hot-added devices in
pci_bus_add_device() just before the new device becomes eligible for driver
binding.

This patch keeps the fs_initcall() for devices present at boot because we
do resource assignment between pci_bus_add_device and the fs_initcall(),
and we don't want to break any fixups that depend on that assignment.  This
is a design issue that may be addressed in the future -- any resource
assignment should be done *before* device_add().

[bhelgaas: changelog]
Signed-off-by: Myron Stowe &lt;myron.stowe@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: add struct pci_host_bridge_window with CPU/bus address offset</title>
<updated>2012-02-24T03:19:00+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2012-02-24T03:19:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0efd5aab41e18a1175f72641696cfda154ba6c87'/>
<id>0efd5aab41e18a1175f72641696cfda154ba6c87</id>
<content type='text'>
Some PCI host bridges apply an address offset, so bus addresses on PCI are
different from CPU addresses.  This patch adds a way for architectures to
tell the PCI core about this offset.  For example:

    LIST_HEAD(resources);
    pci_add_resource_offset(&amp;resources, host-&gt;io_space, host-&gt;io_offset);
    pci_add_resource_offset(&amp;resources, host-&gt;mem_space, host-&gt;mem_offset);
    pci_scan_root_bus(parent, bus, ops, sysdata, &amp;resources);

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Some PCI host bridges apply an address offset, so bus addresses on PCI are
different from CPU addresses.  This patch adds a way for architectures to
tell the PCI core about this offset.  For example:

    LIST_HEAD(resources);
    pci_add_resource_offset(&amp;resources, host-&gt;io_space, host-&gt;io_offset);
    pci_add_resource_offset(&amp;resources, host-&gt;mem_space, host-&gt;mem_offset);
    pci_scan_root_bus(parent, bus, ops, sysdata, &amp;resources);

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: add helpers for building PCI bus resource lists</title>
<updated>2012-01-06T20:10:50+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bhelgaas@google.com</email>
</author>
<published>2011-10-28T22:25:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=45ca9e9730c5acdb482dd95799fd8ac834481897'/>
<id>45ca9e9730c5acdb482dd95799fd8ac834481897</id>
<content type='text'>
We'd like to supply a list of resources when we create a new PCI bus,
e.g., the root bus under a PCI host bridge.  These are helpers for
constructing that list.

These are exported because the plan is to replace this exported interface:
    pci_scan_bus_parented()
with this one:
    pci_add_resource(resources, ...)
    pci_scan_root_bus(..., resources)

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.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'd like to supply a list of resources when we create a new PCI bus,
e.g., the root bus under a PCI host bridge.  These are helpers for
constructing that list.

These are exported because the plan is to replace this exported interface:
    pci_scan_bus_parented()
with this one:
    pci_add_resource(resources, ...)
    pci_scan_root_bus(..., resources)

Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI/sysfs: move bus cpuaffinity to class dev_attrs</title>
<updated>2011-05-21T19:17:13+00:00</updated>
<author>
<name>Yinghai Lu</name>
<email>yinghai@kernel.org</email>
</author>
<published>2011-05-13T00:11:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=dc2c2c9dd513dec6c17df04e8abff795e20a5271'/>
<id>dc2c2c9dd513dec6c17df04e8abff795e20a5271</id>
<content type='text'>
Requested by Greg KH to fix a race condition in the creating of PCI bus
cpuaffinity files.

Acked-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Signed-off-by: Yinghai Lu &lt;yinghai@kernel.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>
Requested by Greg KH to fix a race condition in the creating of PCI bus
cpuaffinity files.

Acked-by: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Signed-off-by: Yinghai Lu &lt;yinghai@kernel.org&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "PCI: allocate bus resources from the top down"</title>
<updated>2010-12-17T18:00:54+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bjorn.helgaas@hp.com</email>
</author>
<published>2010-12-16T17:38:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6db45b76eaa08133187f2cb44d496de7e9503aa8'/>
<id>6db45b76eaa08133187f2cb44d496de7e9503aa8</id>
<content type='text'>
This reverts commit b126b4703afa4010b161784a43650337676dd03b.

We're going back to the old behavior of allocating from bus resources
in _CRS order.

Acked-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@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 reverts commit b126b4703afa4010b161784a43650337676dd03b.

We're going back to the old behavior of allocating from bus resources
in _CRS order.

Acked-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Revert "PCI: fix pci_bus_alloc_resource() hang, prefer positive decode"</title>
<updated>2010-12-17T18:00:38+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bjorn.helgaas@hp.com</email>
</author>
<published>2010-12-16T17:38:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ac57cd5ee1935d1e60de86d75f13f377775f1c96'/>
<id>ac57cd5ee1935d1e60de86d75f13f377775f1c96</id>
<content type='text'>
This reverts commit 82e3e767c21fef2b1b38868e20eb4e470a1e38e3.

We're going back to considering bus resources in the order we found
them (in _CRS order, when we're using _CRS), so we don't need to
define any ordering.

Acked-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@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 reverts commit 82e3e767c21fef2b1b38868e20eb4e470a1e38e3.

We're going back to considering bus resources in the order we found
them (in _CRS order, when we're using _CRS), so we don't need to
define any ordering.

Acked-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: fix pci_bus_alloc_resource() hang, prefer positive decode</title>
<updated>2010-11-12T17:16:08+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bjorn.helgaas@hp.com</email>
</author>
<published>2010-11-10T17:26:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=82e3e767c21fef2b1b38868e20eb4e470a1e38e3'/>
<id>82e3e767c21fef2b1b38868e20eb4e470a1e38e3</id>
<content type='text'>
When a PCI bus has two resources with the same start/end, e.g.,

    pci_bus 0000:04: resource 2 [mem 0xd0000000-0xd7ffffff pref]
    pci_bus 0000:04: resource 7 [mem 0xd0000000-0xd7ffffff]

the previous pci_bus_find_resource_prev() implementation would alternate
between them forever:

    pci_bus_find_resource_prev(... [mem 0xd0000000-0xd7ffffff pref])
        returns [mem 0xd0000000-0xd7ffffff]
    pci_bus_find_resource_prev(... [mem 0xd0000000-0xd7ffffff])
        returns [mem 0xd0000000-0xd7ffffff pref]
    pci_bus_find_resource_prev(... [mem 0xd0000000-0xd7ffffff pref])
        returns [mem 0xd0000000-0xd7ffffff]
    ...

This happened because there was no ordering between two resources with the
same start and end.  A resource that had the same start and end as the
cursor, but was not itself the cursor, was considered to be before the
cursor.

This patch fixes the hang by making a fixed ordering between any two
resources.

In addition, it tries to allocate from positively decoded regions before
using any subtractively decoded resources.  This means we will use a
positive decode region before a subtractive decode one, even if it means
using a smaller address.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=22062
Reported-by: Borislav Petkov &lt;bp@amd64.org&gt;
Tested-by: Borislav Petkov &lt;bp@amd64.org&gt;
Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@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>
When a PCI bus has two resources with the same start/end, e.g.,

    pci_bus 0000:04: resource 2 [mem 0xd0000000-0xd7ffffff pref]
    pci_bus 0000:04: resource 7 [mem 0xd0000000-0xd7ffffff]

the previous pci_bus_find_resource_prev() implementation would alternate
between them forever:

    pci_bus_find_resource_prev(... [mem 0xd0000000-0xd7ffffff pref])
        returns [mem 0xd0000000-0xd7ffffff]
    pci_bus_find_resource_prev(... [mem 0xd0000000-0xd7ffffff])
        returns [mem 0xd0000000-0xd7ffffff pref]
    pci_bus_find_resource_prev(... [mem 0xd0000000-0xd7ffffff pref])
        returns [mem 0xd0000000-0xd7ffffff]
    ...

This happened because there was no ordering between two resources with the
same start and end.  A resource that had the same start and end as the
cursor, but was not itself the cursor, was considered to be before the
cursor.

This patch fixes the hang by making a fixed ordering between any two
resources.

In addition, it tries to allocate from positively decoded regions before
using any subtractively decoded resources.  This means we will use a
positive decode region before a subtractive decode one, even if it means
using a smaller address.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=22062
Reported-by: Borislav Petkov &lt;bp@amd64.org&gt;
Tested-by: Borislav Petkov &lt;bp@amd64.org&gt;
Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen</title>
<updated>2010-10-29T00:11:17+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2010-10-29T00:11:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=18cb657ca1bafe635f368346a1676fb04c512edf'/>
<id>18cb657ca1bafe635f368346a1676fb04c512edf</id>
<content type='text'>
  and branch 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm

* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: register xen pci notifier
  xen: initialize cpu masks for pv guests in xen_smp_init
  xen: add a missing #include to arch/x86/pci/xen.c
  xen: mask the MTRR feature from the cpuid
  xen: make hvc_xen console work for dom0.
  xen: add the direct mapping area for ISA bus access
  xen: Initialize xenbus for dom0.
  xen: use vcpu_ops to setup cpu masks
  xen: map a dummy page for local apic and ioapic in xen_set_fixmap
  xen: remap MSIs into pirqs when running as initial domain
  xen: remap GSIs as pirqs when running as initial domain
  xen: introduce XEN_DOM0 as a silent option
  xen: map MSIs into pirqs
  xen: support GSI -&gt; pirq remapping in PV on HVM guests
  xen: add xen hvm acpi_register_gsi variant
  acpi: use indirect call to register gsi in different modes
  xen: implement xen_hvm_register_pirq
  xen: get the maximum number of pirqs from xen
  xen: support pirq != irq

* 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (27 commits)
  X86/PCI: Remove the dependency on isapnp_disable.
  xen: Update Makefile with CONFIG_BLOCK dependency for biomerge.c
  MAINTAINERS: Add myself to the Xen Hypervisor Interface and remove Chris Wright.
  x86: xen: Sanitse irq handling (part two)
  swiotlb-xen: On x86-32 builts, select SWIOTLB instead of depending on it.
  MAINTAINERS: Add myself for Xen PCI and Xen SWIOTLB maintainer.
  xen/pci: Request ACS when Xen-SWIOTLB is activated.
  xen-pcifront: Xen PCI frontend driver.
  xenbus: prevent warnings on unhandled enumeration values
  xenbus: Xen paravirtualised PCI hotplug support.
  xen/x86/PCI: Add support for the Xen PCI subsystem
  x86: Introduce x86_msi_ops
  msi: Introduce default_[teardown|setup]_msi_irqs with fallback.
  x86/PCI: Export pci_walk_bus function.
  x86/PCI: make sure _PAGE_IOMAP it set on pci mappings
  x86/PCI: Clean up pci_cache_line_size
  xen: fix shared irq device passthrough
  xen: Provide a variant of xen_poll_irq with timeout.
  xen: Find an unbound irq number in reverse order (high to low).
  xen: statically initialize cpu_evtchn_mask_p
  ...

Fix up trivial conflicts in drivers/pci/Makefile
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
  and branch 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm

* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: register xen pci notifier
  xen: initialize cpu masks for pv guests in xen_smp_init
  xen: add a missing #include to arch/x86/pci/xen.c
  xen: mask the MTRR feature from the cpuid
  xen: make hvc_xen console work for dom0.
  xen: add the direct mapping area for ISA bus access
  xen: Initialize xenbus for dom0.
  xen: use vcpu_ops to setup cpu masks
  xen: map a dummy page for local apic and ioapic in xen_set_fixmap
  xen: remap MSIs into pirqs when running as initial domain
  xen: remap GSIs as pirqs when running as initial domain
  xen: introduce XEN_DOM0 as a silent option
  xen: map MSIs into pirqs
  xen: support GSI -&gt; pirq remapping in PV on HVM guests
  xen: add xen hvm acpi_register_gsi variant
  acpi: use indirect call to register gsi in different modes
  xen: implement xen_hvm_register_pirq
  xen: get the maximum number of pirqs from xen
  xen: support pirq != irq

* 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (27 commits)
  X86/PCI: Remove the dependency on isapnp_disable.
  xen: Update Makefile with CONFIG_BLOCK dependency for biomerge.c
  MAINTAINERS: Add myself to the Xen Hypervisor Interface and remove Chris Wright.
  x86: xen: Sanitse irq handling (part two)
  swiotlb-xen: On x86-32 builts, select SWIOTLB instead of depending on it.
  MAINTAINERS: Add myself for Xen PCI and Xen SWIOTLB maintainer.
  xen/pci: Request ACS when Xen-SWIOTLB is activated.
  xen-pcifront: Xen PCI frontend driver.
  xenbus: prevent warnings on unhandled enumeration values
  xenbus: Xen paravirtualised PCI hotplug support.
  xen/x86/PCI: Add support for the Xen PCI subsystem
  x86: Introduce x86_msi_ops
  msi: Introduce default_[teardown|setup]_msi_irqs with fallback.
  x86/PCI: Export pci_walk_bus function.
  x86/PCI: make sure _PAGE_IOMAP it set on pci mappings
  x86/PCI: Clean up pci_cache_line_size
  xen: fix shared irq device passthrough
  xen: Provide a variant of xen_poll_irq with timeout.
  xen: Find an unbound irq number in reverse order (high to low).
  xen: statically initialize cpu_evtchn_mask_p
  ...

Fix up trivial conflicts in drivers/pci/Makefile
</pre>
</div>
</content>
</entry>
<entry>
<title>PCI: allocate bus resources from the top down</title>
<updated>2010-10-26T22:33:37+00:00</updated>
<author>
<name>Bjorn Helgaas</name>
<email>bjorn.helgaas@hp.com</email>
</author>
<published>2010-10-26T21:41:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=b126b4703afa4010b161784a43650337676dd03b'/>
<id>b126b4703afa4010b161784a43650337676dd03b</id>
<content type='text'>
Allocate space from the highest-address PCI bus resource first, then work
downward.

Previously, we looked for space in PCI host bridge windows in the order
we discovered the windows.  For example, given the following windows
(discovered via an ACPI _CRS method):

    pci_root PNP0A03:00: host bridge window [mem 0x000a0000-0x000bffff]
    pci_root PNP0A03:00: host bridge window [mem 0x000c0000-0x000effff]
    pci_root PNP0A03:00: host bridge window [mem 0x000f0000-0x000fffff]
    pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xf7ffffff]
    pci_root PNP0A03:00: host bridge window [mem 0xff980000-0xff980fff]
    pci_root PNP0A03:00: host bridge window [mem 0xff97c000-0xff97ffff]
    pci_root PNP0A03:00: host bridge window [mem 0xfed20000-0xfed9ffff]

we attempted to allocate from [mem 0x000a0000-0x000bffff] first, then
[mem 0x000c0000-0x000effff], and so on.

With this patch, we allocate from [mem 0xff980000-0xff980fff] first, then
[mem 0xff97c000-0xff97ffff], [mem 0xfed20000-0xfed9ffff], etc.

Allocating top-down follows Windows practice, so we're less likely to
trip over BIOS defects in the _CRS description.

On the machine above (a Dell T3500), the [mem 0xbff00000-0xbfffffff] region
doesn't actually work and is likely a BIOS defect.  The symptom is that we
move the AHCI controller to 0xbff00000, which leads to "Boot has failed,
sleeping forever," a BUG in ahci_stop_engine(), or some other boot failure.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228#c43
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=620313
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=629933
Reported-by: Brian Bloniarz &lt;phunge0@hotmail.com&gt;
Reported-and-tested-by: Stefan Becker &lt;chemobejk@gmail.com&gt;
Reported-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@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>
Allocate space from the highest-address PCI bus resource first, then work
downward.

Previously, we looked for space in PCI host bridge windows in the order
we discovered the windows.  For example, given the following windows
(discovered via an ACPI _CRS method):

    pci_root PNP0A03:00: host bridge window [mem 0x000a0000-0x000bffff]
    pci_root PNP0A03:00: host bridge window [mem 0x000c0000-0x000effff]
    pci_root PNP0A03:00: host bridge window [mem 0x000f0000-0x000fffff]
    pci_root PNP0A03:00: host bridge window [mem 0xbff00000-0xf7ffffff]
    pci_root PNP0A03:00: host bridge window [mem 0xff980000-0xff980fff]
    pci_root PNP0A03:00: host bridge window [mem 0xff97c000-0xff97ffff]
    pci_root PNP0A03:00: host bridge window [mem 0xfed20000-0xfed9ffff]

we attempted to allocate from [mem 0x000a0000-0x000bffff] first, then
[mem 0x000c0000-0x000effff], and so on.

With this patch, we allocate from [mem 0xff980000-0xff980fff] first, then
[mem 0xff97c000-0xff97ffff], [mem 0xfed20000-0xfed9ffff], etc.

Allocating top-down follows Windows practice, so we're less likely to
trip over BIOS defects in the _CRS description.

On the machine above (a Dell T3500), the [mem 0xbff00000-0xbfffffff] region
doesn't actually work and is likely a BIOS defect.  The symptom is that we
move the AHCI controller to 0xbff00000, which leads to "Boot has failed,
sleeping forever," a BUG in ahci_stop_engine(), or some other boot failure.

Reference: https://bugzilla.kernel.org/show_bug.cgi?id=16228#c43
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=620313
Reference: https://bugzilla.redhat.com/show_bug.cgi?id=629933
Reported-by: Brian Bloniarz &lt;phunge0@hotmail.com&gt;
Reported-and-tested-by: Stefan Becker &lt;chemobejk@gmail.com&gt;
Reported-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Signed-off-by: Bjorn Helgaas &lt;bjorn.helgaas@hp.com&gt;
Signed-off-by: Jesse Barnes &lt;jbarnes@virtuousgeek.org&gt;
</pre>
</div>
</content>
</entry>
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