[Trusty SRU] Add MSI/MSI-X driver for APM PCI bus

[Ike Panhc]

This is the driver to enable MSI function on AppliedMicro X-Gene SOC
which reduces interrupt overhead. For 10G or faster networking, this
function is critical to network performance.

This patch will only affect on APM X-Gene SOC, where pci-xgene* only
loaded according to device tree and the new-added helper in msi_bitmap.c
only called from pci-xgene*

I've tested this patch with 1G full networking load, the interrupt
rate drops from 99608 Int/s to 88527 Int/s which means less cpu loading.

Tanmay Inamdar (1):
  UBUNTU: SAUCE: Add MSI/MSI-X driver for APM PCI bus

 arch/arm64/boot/dts/apm-storm.dtsi        |  41 ++-
 arch/arm64/include/asm/msi_bitmap.h       |  36 ++
 arch/arm64/kernel/Makefile                |   1 +
 arch/arm64/kernel/msi_bitmap.c            | 134 +++++++
 debian.master/config/config.common.ubuntu |   1 +
 drivers/pci/host/Kconfig                  |   4 +
 drivers/pci/host/Makefile                 |   1 +
 drivers/pci/host/pci-xgene-msi.c          | 593 ++++++++++++++++++++++++++++++
 drivers/pci/host/pci-xgene.c              |   6 +-
 9 files changed, 807 insertions(+), 10 deletions(-)
 create mode 100644 arch/arm64/include/asm/msi_bitmap.h
 create mode 100644 arch/arm64/kernel/msi_bitmap.c
 create mode 100644 drivers/pci/host/pci-xgene-msi.c

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1.9.1