PCI: Add pcie_flags_reg to cache PCIe capabilities register

Since PCI Express Capabilities Register is read only, cache its value
into struct pci_dev to avoid repeatedly calling pci_read_config_*().

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>(cherry picked from commit 786e22885d9959fda0473ace5a61cb11620fba9b)
powerpc/PCI: Override pcibios_window_alignment()

This patch implements pcibios_window_alignment() so powerpc platforms can
force P2P bridge windows to be at larger alignments than the PCI spec
requires.

[bhelgaas: changelog]
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
(cherry picked from commit 4c2245bb5c9c6e9950ee8919b4462dfa77f7a28f)
powerpc/powernv: I/O and memory alignment for P2P bridges

The patch implements ppc_md.pcibios_window_alignment for powernv
platform so that the resource reassignment in PCI core will be
done according to the I/O and memory alignment returned from
powernv platform. The alignments returned from powernv platform
is closely depending on the scheme for PE segmenting. Besides,
the patch isn't useful for now, but the subsequent patches will
be working based on it.

[bhelgaas: use pci_pcie_type() since pci_dev.pcie_type was removed]
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
(cherry picked from commit 271fd03a3013b106ccc178d54219c1be0c9759b7)
hvc_console: Better kernel console support

hvc_console has two methods to instanciate the consoles.

hvc_instanciate is meant to be called at early boot, while hvc_alloc is
called for more dynamically probed objects.

Currently, it only deals with adding kernel consoles in the former case,
which means for example that if a console only uses dynamic probing, it
will never be usable as a kernel console even when specifying
console=hvc0 explicitly, which could be considered annoying...

More specifically, on pseries, we only do the early instanciate for the
console currently used by the firmware, so if you have your firmware
configured to go to a video card, for example, you cannot get your
kernel console, oops messages, etc... on your serial port or hypervisor
console, which would be handy to deal with oopses.

This fixes it by checking if hvc_console.flags & CON_ENABLED is set when
registering a new dynamic console, and if not, redo the index check and
re-register the console if the index matches, allowing console=hvcN to
work.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
(cherry picked from commit 92057a493af4bb56928a762ad0423200b835d995)

Conflicts:
	drivers/tty/hvc/hvc_console.c
hvc_vio: Improve registration of udbg backend

The pseries hvterm driver only registers a udbg backend (for xmon and
other low level debugging mechanisms) when hvc0 is recognized as the
firmware console at boot time, not if it's detected later on, for
example because the firmware is using a graphics card.

This can make debugging challenging especially under X11, and there's
really no good reason for that limitation, so let's hookup udbg
whenever hvc0 is detected instead.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
(cherry picked from commit d1cfc0ce5d3196ccd88b9d868bb7cbcab61e0a31)