linux-toradex.git/kernel/resource.c, branch v2.6.38.5

resources: add arch hook for preventing allocation in reserved areas

2010-12-17T18:01:09+00:00

This adds arch_remove_reservations(), which an arch can implement if it
needs to protect part of the address space from allocation.

Sometimes that can be done by just putting a region in the resource tree,
but there are cases where that doesn't work well.  For example, x86 BIOS
E820 reservations are not related to devices, so they may overlap part of,
all of, or more than a device resource, so they may not end up at the
correct spot in the resource tree.

Acked-by: H. Peter Anvin 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

Revert "resources: support allocating space within a region from the top down"

2010-12-17T18:00:59+00:00

This reverts commit e7f8567db9a7f6b3151b0b275e245c1cef0d9c70.

Acked-by: H. Peter Anvin 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6

2010-10-28T18:59:52+00:00

* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (27 commits)
  x86: allocate space within a region top-down
  x86: update iomem_resource end based on CPU physical address capabilities
  x86/PCI: allocate space from the end of a region, not the beginning
  PCI: allocate bus resources from the top down
  resources: support allocating space within a region from the top down
  resources: handle overflow when aligning start of available area
  resources: ensure callback doesn't allocate outside available space
  resources: factor out resource_clip() to simplify find_resource()
  resources: add a default alignf to simplify find_resource()
  x86/PCI: MMCONFIG: fix region end calculation
  PCI: Add support for polling PME state on suspended legacy PCI devices
  PCI: Export some PCI PM functionality
  PCI: fix message typo
  PCI: log vendor/device ID always
  PCI: update Intel chipset names and defines
  PCI: use new ccflags variable in Makefile
  PCI: add PCI_MSIX_TABLE/PBA defines
  PCI: add PCI vendor id for STmicroelectronics
  x86/PCI: irq and pci_ids patch for Intel Patsburg DeviceIDs
  PCI: OLPC: Only enable PCI configuration type override on XO-1
  ...

kernel/resource.c: handle reinsertion of an already-inserted resource

2010-10-28T01:03:18+00:00

If the same resource is inserted to the resource tree (maybe not on
purpose), a dead loop will be created.  In this situation, The kernel does
not report any warning or error :(

  The command below will show a endless print.
  #cat /proc/iomem

[akpm@linux-foundation.org: add WARN_ON()]
Signed-off-by: Huang Shijie 
Cc: Jesse Barnes 
Cc: Bjorn Helgaas 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

resources: support allocating space within a region from the top down

2010-10-26T22:33:31+00:00

Allocate space from the top of a region first, then work downward,
if an architecture desires this.

When we allocate space from a resource, we look for gaps between children
of the resource.  Previously, we always looked at gaps from the bottom up.
For example, given this:

    [mem 0xbff00000-0xf7ffffff] PCI Bus 0000:00
      [mem 0xbff00000-0xbfffffff] gap -- available
      [mem 0xc0000000-0xdfffffff] PCI Bus 0000:02
      [mem 0xe0000000-0xf7ffffff] gap -- available

we attempted to allocate from the [mem 0xbff00000-0xbfffffff] gap first,
then the [mem 0xe0000000-0xf7ffffff] gap.

With this patch an architecture can choose to allocate from the top gap
[mem 0xe0000000-0xf7ffffff] first.

We can't do this across the board because iomem_resource.end is initialized
to 0xffffffff_ffffffff on 64-bit architectures, and most machines can't
address the entire 64-bit physical address space.  Therefore, we only
allocate top-down if the arch requests it by clearing
"resource_alloc_from_bottom".

Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

resources: handle overflow when aligning start of available area

2010-10-26T22:33:28+00:00

If tmp.start is near ~0, ALIGN(tmp.start) may overflow, which would
make us think there's more available space than there really is.  We
would likely return something that conflicts with a previous resource,
which would cause a failure when allocate_resource() requests the newly-
allocated region.

Reference: https://bugzilla.redhat.com/show_bug.cgi?id=646027
Reported-by: Fabrice Bellet 
Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

resources: ensure callback doesn't allocate outside available space

2010-10-26T22:33:26+00:00

The alignment callback returns a proposed location, which may have been
adjusted to avoid ISA aliases or for other architecture-specific reasons.

We already had a check ("tmp.start < tmp.end") to make sure the callback
doesn't return an area that extends past the available area.  This patch
reworks the check to make sure it doesn't return an area that extends
either below or above the available area.

Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

resources: factor out resource_clip() to simplify find_resource()

2010-10-26T22:33:24+00:00

This factors out the min/max clipping to simplify find_resource().
No functional change.

Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

resources: add a default alignf to simplify find_resource()

2010-10-26T22:33:22+00:00

This removes a test from find_resource(), which is getting cluttered.
No functional change.

Signed-off-by: Bjorn Helgaas 
Signed-off-by: Jesse Barnes

resource: shared I/O region support

2010-05-11T19:01:10+00:00

SuperIO devices share regions and use lock/unlock operations to chip
select.  We therefore need to be able to request a resource and wait for
it to be freed by whichever other SuperIO device currently hogs it.
Right now you have to poll which is horrible.

Add a MUXED field to IO port resources. If the MUXED field is set on the
resource and on the request (via request_muxed_region) then we block
until the previous owner of the muxed resource releases their region.

This allows us to implement proper resource sharing and locking for
superio chips using code of the form

enable_my_superio_dev() {
	request_muxed_region(0x44, 0x02, "superio:watchdog");
	outb() ..sequence to enable chip
}

disable_my_superio_dev() {
	outb() .. sequence of disable chip
	release_region(0x44, 0x02);
}

Signed-off-by: Giel van Schijndel 
Signed-off-by: Alan Cox 
Signed-off-by: Jesse Barnes