On Tue, Oct 03, 2017 at 03:45:38PM +0100, John Garry wrote: > On 02/10/2017 18:28, Lorenzo Pieralisi wrote: > >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 > >Signed-workarounds") > >Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> > >Cc: Will Deacon <will.deacon@xxxxxxx> > >Cc: Hanjun Guo <hanjun.guo@xxxxxxxxxx> > >Cc: Sudeep Holla <sudeep.holla@xxxxxxx> > >Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > >Cc: Robin Murphy <robin.murphy@xxxxxxx> > >Cc: Zhou Wang <wangzhou1@xxxxxxxxxxxxx> > >Cc: Alex Williamson <alex.williamson@xxxxxxxxxx> > >--- > >v1 -> v2: > > > >- Reworked ACS enablement logic and based on root complex to SMMU > > ids firmware mapping detection > >- Rebased against v4.14-rc3 > > > >v1: https://marc.info/?l=linux-acpi&m=150584059818925&w=2 > > > > drivers/acpi/arm64/iort.c | 35 +++++++++++++++++++++++++++++++++++ > > 1 file changed, 35 insertions(+) > > > >diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > >index 9565d57..de56394 100644 > >--- a/drivers/acpi/arm64/iort.c > >+++ b/drivers/acpi/arm64/iort.c > >@@ -1178,12 +1178,44 @@ static int __init iort_add_smmu_platform_device(struct acpi_iort_node *node) > > 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)) { > > Hi Lorenzo, > > There are a couple of places now which check for any SMMU type. > Should we have a helper function/macro to condense, like this: > IORT_TYPE_MASK(type) & IORT_IOMMU_TYPE > > Personal taste, I guess. I agree, I will add that macro for 4.15, I would like to merge this as a fix now. > BTW, unfortunately we can't re-test this week due to Chinese holiday. Understood, I just would like to get some coverage before asking Will and Catalin to queue it as a fix. Cheers, Lorenzo > Cheers, > John > > >+ 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)) { > > > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html