linux-toradex.git/drivers/pci/rom.c, branch v4.10

PCI: Add comments about ROM BAR updating

2016-11-30T00:05:09+00:00

pci_update_resource() updates a hardware BAR so its address matches the
kernel's struct resource UNLESS it's a disabled ROM BAR.  We only update
those when we enable the ROM.

It's not obvious from the code why ROM BARs should be handled specially.
Apparently there are Matrox devices with defective ROM BARs that read as
zero when disabled.  That means that if pci_enable_rom() reads the disabled
BAR, sets PCI_ROM_ADDRESS_ENABLE (without re-inserting the address), and
writes it back, it would enable the ROM at address zero.

Add comments and references to explain why we can't make the code look more
rational.

The code changes are from 755528c860b0 ("Ignore disabled ROM resources at
setup") and 8085ce084c0f ("[PATCH] Fix PCI ROM mapping").

Link: https://lkml.org/lkml/2005/8/30/138
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Gavin Shan

PCI: Remove unused IORESOURCE_ROM_COPY and IORESOURCE_ROM_BIOS_COPY

2016-03-12T12:00:29+00:00

The IORESOURCE_ROM_COPY and IORESOURCE_ROM_BIOS_COPY bits are unused.
Remove them and code that depends on them.

Signed-off-by: Bjorn Helgaas

PCI: Clean up pci_map_rom() whitespace

2016-03-12T12:00:28+00:00

Remove unnecessary indentation in pci_map_rom().  This is logically part of
the previous patch; I split it out to make the critical changes in that
patch more obvious.  No functional change intended.

Signed-off-by: Bjorn Helgaas

PCI: Set ROM shadow location in arch code, not in PCI core

2016-03-08T18:14:31+00:00

IORESOURCE_ROM_SHADOW means there is a copy of a device's option ROM in
RAM.  The existence of such a copy and its location are arch-specific.
Previously the IORESOURCE_ROM_SHADOW flag was set in arch code, but the
0xC0000-0xDFFFF location was hard-coded into the PCI core.

If we're using a shadow copy in RAM, disable the ROM BAR and release the
address space it was consuming.  Move the location information from the PCI
core to the arch code that sets IORESOURCE_ROM_SHADOW.  Save the location
of the RAM copy in the struct resource for PCI_ROM_RESOURCE.

After this change, pci_map_rom() will call pci_assign_resource() and
pci_enable_rom() for these IORESOURCE_ROM_SHADOW resources, which we did
not do before.  This is safe because:

  - pci_assign_resource() will do nothing because the resource is marked
    IORESOURCE_PCI_FIXED, which means we can't move it, and

  - pci_enable_rom() will not turn on the ROM BAR's enable bit because the
    resource is marked IORESOURCE_ROM_SHADOW, which means it is in RAM
    rather than in PCI memory space.

Storing the location in the struct resource means "lspci" will show the
shadow location, not the value from the ROM BAR.

Signed-off-by: Bjorn Helgaas

PCI: Don't enable/disable ROM BAR if we're using a RAM shadow copy

2016-03-08T18:14:31+00:00

If we're using a RAM shadow copy instead of the ROM BAR, we don't need to
touch the ROM BAR enable bit.

Signed-off-by: Bjorn Helgaas

Merge branches 'pci/hotplug' and 'pci/resource' into next

2016-01-15T18:33:29+00:00

* pci/hotplug:
  PCI: ibmphp: Remove unneeded NULL test
  PCI: hotplug: Use list_for_each_entry() to simplify code
  PCI: acpiphp_ibm: Fix null dereferences on null ibm_slot

* pci/resource:
  PCI: Avoid iterating through memory outside the resource window
  PCI: Fix minimum allocation address overwrite

PCI: Avoid iterating through memory outside the resource window

2016-01-08T18:16:04+00:00

If the 'image' pointer has been advanced more than 'size', we've already
iterated through memory outside the resource window.

We have zero control over whatever we find in the option ROM, if it's even
an option ROM and not just an accident of random data just happening to
look like an option ROM.

Signed-off-by: Edward O'Callaghan 
Signed-off-by: Bjorn Helgaas

PCI: Print warnings for all invalid expansion ROM headers

2015-12-11T01:38:06+00:00

We've always validated that both bytes of the Expansion ROM signature and
all four bytes of the PCI Data Structure signature (see PCI Firmware spec
r3.0, sec 5.1.1), but we only printed a warning if the first byte of the
ROM signature was invalid.

Print warnings if *any* of those bytes are invalid.  Note that we only look
at these headers if we map or read the ROM.

[bhelgaas: changelog, tweak printk format]
Signed-off-by: Vladis Dronov 
Signed-off-by: Bjorn Helgaas

PCI: Fix infinite loop with ROM image of size 0

2015-01-23T23:42:59+00:00

If the image size would ever read as 0, pci_get_rom_size() could keep
processing the same image over and over again.  Exit the loop if we ever
read a length of zero.

This fixes a soft lockup on boot when the radeon driver calls
pci_get_rom_size() on an AMD Radeon R7 250X PCIe discrete graphics card.

[bhelgaas: changelog, reference]
Link: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1386973
Reported-by: Federico 
Signed-off-by: Michel Dänzer 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Alex Deucher 
CC: stable@vger.kernel.org

PCI: Whitespace cleanup

2014-06-11T02:20:19+00:00

Fix various whitespace errors.

No functional change.

[bhelgaas: fix other similar problems]
Signed-off-by: Ryan Desfosses 
Signed-off-by: Bjorn Helgaas