ACPI/IORT: Fix PCI ACS enablement
authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Mon, 2 Oct 2017 17:28:44 +0000 (18:28 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Wed, 4 Oct 2017 16:34:41 +0000 (17:34 +0100)
commit37f6b42e9c2966b08c7df5cfddc0d73c39cead4a
treee426ac90469207400f5da22cc60306ec4b6653f9
parent0a6de8b8668a2cfc0912a1d7df21107e1a075a3a
ACPI/IORT: Fix PCI ACS enablement

commit f6810c15cf97 ("iommu/arm-smmu: Clean up early-probing
workarounds") removed kernel code that was allowing to initialize
and probe the SMMU devices early (ie earlier than PCI devices, through
linker script callback entries) in the boot process because it was not
needed any longer in that the SMMU devices/drivers now support deferred
probing.

Since the SMMUs probe routines are also in charge of requesting global
PCI ACS kernel enablement, commit f6810c15cf97 ("iommu/arm-smmu: Clean
up early-probing workarounds") also postponed PCI ACS enablement to
SMMUs devices probe time, which is too late given that PCI devices needs
to detect if PCI ACS is enabled to init the respective capability
through the following call path:

pci_device_add()
 -> pci_init_capabilities()
  -> pci_enable_acs()

Add code in the ACPI IORT SMMU platform devices initialization path
(that is called before ACPI PCI enumeration) to detect if there
exists firmware mappings to map root complexes ids to SMMU ids
and if so enable ACS for the system.

Fixes: f6810c15cf97 ("iommu/arm-smmu: Clean up early-probing workarounds")
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Nate Watterson <nwatters@codeaurora.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Zhou Wang <wangzhou1@hisilicon.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
drivers/acpi/arm64/iort.c