mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

ACPI/IORT: Fix PCI ACS enablement 

commit f6810c15cf ("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 f6810c15cf ("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: f6810c15cf ("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>
This commit is contained in:
Lorenzo Pieralisi 2017-10-02 18:28:44 +01:00 committed by Catalin Marinas
parent 0a6de8b866
commit 37f6b42e9c
1 changed files with 35 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

35
drivers/acpi/arm64/iort.c
View File

@ -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)) {