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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2017-10-02 20:28:44 +0300
committerCatalin Marinas <catalin.marinas@arm.com>2017-10-04 19:34:41 +0300
commit37f6b42e9c2966b08c7df5cfddc0d73c39cead4a (patch)
treee426ac90469207400f5da22cc60306ec4b6653f9
parent0a6de8b8668a2cfc0912a1d7df21107e1a075a3a (diff)
downloadlinux-37f6b42e9c2966b08c7df5cfddc0d73c39cead4a.tar.xz
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>
-rw-r--r--drivers/acpi/arm64/iort.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 9565d572f8dd..de56394dd161 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1178,12 +1178,44 @@ dev_put:
return ret;
}
+static bool __init iort_enable_acs(struct acpi_iort_node *iort_node)
+{
+ if (iort_node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX) {
+ struct acpi_iort_node *parent;
+ struct acpi_iort_id_mapping *map;
+ int i;
+
+ map = ACPI_ADD_PTR(struct acpi_iort_id_mapping, iort_node,
+ iort_node->mapping_offset);
+
+ for (i = 0; i < iort_node->mapping_count; i++, map++) {
+ if (!map->output_reference)
+ continue;
+
+ parent = ACPI_ADD_PTR(struct acpi_iort_node,
+ iort_table, map->output_reference);
+ /*
+ * If we detect a RC->SMMU mapping, make sure
+ * we enable ACS on the system.
+ */
+ if ((parent->type == ACPI_IORT_NODE_SMMU) ||
+ (parent->type == ACPI_IORT_NODE_SMMU_V3)) {
+ pci_request_acs();
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
+
static void __init iort_init_platform_devices(void)
{
struct acpi_iort_node *iort_node, *iort_end;
struct acpi_table_iort *iort;
struct fwnode_handle *fwnode;
int i, ret;
+ bool acs_enabled = false;
/*
* iort_table and iort both point to the start of IORT table, but
@@ -1203,6 +1235,9 @@ static void __init iort_init_platform_devices(void)
return;
}
+ if (!acs_enabled)
+ acs_enabled = iort_enable_acs(iort_node);
+
if ((iort_node->type == ACPI_IORT_NODE_SMMU) ||
(iort_node->type == ACPI_IORT_NODE_SMMU_V3)) {