Re: [PATCH V6 01/13] pci, acpi, x86, ia64: Move ACPI host bridge device companion assignment to core code.
From: Tomasz Nowicki
Date: Wed May 04 2016 - 04:11:13 EST
On 27.04.2016 04:45, Bjorn Helgaas wrote:
[question for Rafael below]
On Fri, Apr 15, 2016 at 07:06:36PM +0200, Tomasz Nowicki wrote:
Currently we have two platforms (x86 & ia64) capable of PCI ACPI host
bridge initialization. They both use arch-specific sysdata to pass down
parent device reference and both rely on NULL parent in pci_create_root_bus()
to validate sysdata content.
It looks hacky and prevents us from getting some firmware specific
info for PCI host controller based on its acpi_device structure
in generic pci_create_root_bus() function. However, we overcome that
blocker by passing down parent device via pci_create_root_bus parameter
(as the ACPI device type). Then we use ACPI_COMPANION_SET in core code
for ACPI boot method only. ACPI_COMPANION_SET is safe to run for all
cases DT, ACPI and DT&ACPI.
Since now PCI core code is setting ACPI companion device for us,
x86 & ia64 specific ACPI companion device setting turns out to be dead now.
We can get rid of it, including related companion reference from
PCI sysdata structure. Aslo, PCI_CONTROLLER macro cannot return valid
companion device anymore. Therefore we need to convert its usage to
ACPI_COMPANION.
Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Tested-by: Duc Dang <dhdang@xxxxxxx>
Tested-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
Tested-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Tested-by: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
Tested-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
---
arch/ia64/hp/common/sba_iommu.c | 2 +-
arch/ia64/include/asm/pci.h | 1 -
arch/ia64/pci/pci.c | 16 ----------------
arch/ia64/sn/kernel/io_acpi_init.c | 4 ++--
arch/x86/include/asm/pci.h | 3 ---
arch/x86/pci/acpi.c | 17 -----------------
drivers/acpi/pci_root.c | 7 ++++++-
drivers/pci/probe.c | 2 ++
8 files changed, 11 insertions(+), 41 deletions(-)
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index a6d6190..78e4444 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -1981,7 +1981,7 @@ sba_connect_bus(struct pci_bus *bus)
if (PCI_CONTROLLER(bus)->iommu)
return;
- handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
+ handle = acpi_device_handle(ACPI_COMPANION(bus->bridge));
if (!handle)
return;
diff --git a/arch/ia64/include/asm/pci.h b/arch/ia64/include/asm/pci.h
index c0835b0..12423f4 100644
--- a/arch/ia64/include/asm/pci.h
+++ b/arch/ia64/include/asm/pci.h
@@ -63,7 +63,6 @@ extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
#define pci_legacy_write platform_pci_legacy_write
struct pci_controller {
- struct acpi_device *companion;
void *iommu;
int segment;
int node; /* nearest node with memory or NUMA_NO_NODE for global allocation */
diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 8f6ac2f..978d6af 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -301,28 +301,12 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
}
info->controller.segment = root->segment;
- info->controller.companion = device;
info->controller.node = acpi_get_node(device->handle);
INIT_LIST_HEAD(&info->io_resources);
return acpi_pci_root_create(root, &pci_acpi_root_ops,
&info->common, &info->controller);
}
-int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
-{
- /*
- * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
- * here, pci_create_root_bus() has been called by someone else and
- * sysdata is likely to be different from what we expect. Let it go in
- * that case.
- */
- if (!bridge->dev.parent) {
- struct pci_controller *controller = bridge->bus->sysdata;
- ACPI_COMPANION_SET(&bridge->dev, controller->companion);
- }
- return 0;
-}
-
void pcibios_fixup_device_resources(struct pci_dev *dev)
{
int idx;
diff --git a/arch/ia64/sn/kernel/io_acpi_init.c b/arch/ia64/sn/kernel/io_acpi_init.c
index 231234c..e454492 100644
--- a/arch/ia64/sn/kernel/io_acpi_init.c
+++ b/arch/ia64/sn/kernel/io_acpi_init.c
@@ -132,7 +132,7 @@ sn_get_bussoft_ptr(struct pci_bus *bus)
struct acpi_resource_vendor_typed *vendor;
- handle = acpi_device_handle(PCI_CONTROLLER(bus)->companion);
+ handle = acpi_device_handle(ACPI_COMPANION(bus->bridge));
status = acpi_get_vendor_resource(handle, METHOD_NAME__CRS,
&sn_uuid, &buffer);
if (ACPI_FAILURE(status)) {
@@ -360,7 +360,7 @@ sn_acpi_get_pcidev_info(struct pci_dev *dev, struct pcidev_info **pcidev_info,
acpi_status status;
struct acpi_buffer name_buffer = { ACPI_ALLOCATE_BUFFER, NULL };
- rootbus_handle = acpi_device_handle(PCI_CONTROLLER(dev)->companion);
+ rootbus_handle = acpi_device_handle(ACPI_COMPANION(dev->bus->bridge));
status = acpi_evaluate_integer(rootbus_handle, METHOD_NAME__SEG, NULL,
&segment);
if (ACPI_SUCCESS(status)) {
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index 9ab7507..24de07d 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -14,9 +14,6 @@
struct pci_sysdata {
int domain; /* PCI domain */
int node; /* NUMA node */
-#ifdef CONFIG_ACPI
- struct acpi_device *companion; /* ACPI companion device */
-#endif
#ifdef CONFIG_X86_64
void *iommu; /* IOMMU private data */
#endif
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 3cd6983..f4ca17a 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -340,7 +340,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
struct pci_sysdata sd = {
.domain = domain,
.node = node,
- .companion = root->device
};
memcpy(bus->sysdata, &sd, sizeof(sd));
@@ -355,7 +354,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
else {
info->sd.domain = domain;
info->sd.node = node;
- info->sd.companion = root->device;
bus = acpi_pci_root_create(root, &acpi_pci_root_ops,
&info->common, &info->sd);
}
@@ -373,21 +371,6 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
return bus;
}
-int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
-{
- /*
- * We pass NULL as parent to pci_create_root_bus(), so if it is not NULL
- * here, pci_create_root_bus() has been called by someone else and
- * sysdata is likely to be different from what we expect. Let it go in
- * that case.
- */
- if (!bridge->dev.parent) {
- struct pci_sysdata *sd = bridge->bus->sysdata;
- ACPI_COMPANION_SET(&bridge->dev, sd->companion);
- }
- return 0;
-}
-
int __init pci_acpi_init(void)
{
struct pci_dev *dev = NULL;
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index ae3fe4e..4581e0e 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -564,6 +564,11 @@ static int acpi_pci_root_add(struct acpi_device *device,
}
}
+ /*
+ * pci_create_root_bus() needs to detect the parent device type,
+ * so initialize its companion data accordingly.
+ */
+ ACPI_COMPANION_SET(&device->dev, device);
root->device = device;
root->segment = segment & 0xFFFF;
strcpy(acpi_device_name(device), ACPI_PCI_ROOT_DEVICE_NAME);
@@ -846,7 +851,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
pci_acpi_root_add_resources(info);
pci_add_resource(&info->resources, &root->secondary);
- bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
+ bus = pci_create_root_bus(&device->dev, busnum, ops->pci_ops,
sysdata, &info->resources);
"device" here is a struct acpi_device *. Rafael, is that the right
thing to do? I dimly recall proposing something similar long ago and
that it turned out to be a bad idea.
Joining Bjorn's question. Rafael, do you recall what was the issue here
from the past?
Thanks,
Tomasz