| Message ID | 1452691267-32240-12-git-send-email-tn@semihalf.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Wed, Jan 13, 2016 at 02:20:57PM +0100, Tomasz Nowicki wrote: > Currently we have two platforms (x86 & ia64) capable of PCI ACPI host > bridge initialization. They both use sysdata pill to pass down parent pill ? > device reference and both relay on NULL parent in pci_create_root_bus() s/relay/rely > to validate sysdata content. > > It looks hacky and prevent us from getting some frimware specific "prevents us from getting some firmware..." > info for PCI host controller e.g. bus domain number. > However, it seems we can overcome that blocker by passing down parent It does not seem, either this patch overcomes the issue and it is accepted, or it does not and it is discarded. > device via pci_create_root_bus parameter (as the ACPI device type) I do not understand what you mean by "as the ACPI device type". > and using ACPI_COMPANION_SET in core code for ACPI boot method. > ACPI_COMPANION_SET is safe to run for all cases DT, ACPI and DT&ACPI. > > Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Signed-off-by: Tomasz Nowicki <tn@semihalf.com> > --- > drivers/acpi/pci_root.c | 5 ++++- > drivers/pci/probe.c | 2 ++ > 2 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index ae3fe4e..a65c8c2 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -846,7 +846,10 @@ 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, > + > + /* Root bridge device needs to be sure of parent ACPI type */ > + ACPI_COMPANION_SET(&device->dev, device); I do not understand why the code above is needed, can you elaborate please ? Thanks, Lorenzo > + bus = pci_create_root_bus(&device->dev, busnum, ops->pci_ops, > sysdata, &info->resources); > if (!bus) > goto out_release_info; > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 553a029..cad836f 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2107,6 +2107,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, > bridge->dev.parent = parent; > bridge->dev.release = pci_release_host_bridge_dev; > dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); > + ACPI_COMPANION_SET(&bridge->dev, > + parent ? to_acpi_device_node(parent->fwnode) : NULL); > error = pcibios_root_bridge_prepare(bridge); > if (error) { > kfree(bridge); > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 19.01.2016 17:02, Lorenzo Pieralisi wrote: > On Wed, Jan 13, 2016 at 02:20:57PM +0100, Tomasz Nowicki wrote: [...] >> device via pci_create_root_bus parameter (as the ACPI device type) > > I do not understand what you mean by "as the ACPI device type". See below. > >> and using ACPI_COMPANION_SET in core code for ACPI boot method. >> ACPI_COMPANION_SET is safe to run for all cases DT, ACPI and DT&ACPI. >> >> Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >> Signed-off-by: Tomasz Nowicki <tn@semihalf.com> >> --- >> drivers/acpi/pci_root.c | 5 ++++- >> drivers/pci/probe.c | 2 ++ >> 2 files changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c >> index ae3fe4e..a65c8c2 100644 >> --- a/drivers/acpi/pci_root.c >> +++ b/drivers/acpi/pci_root.c >> @@ -846,7 +846,10 @@ 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, >> + >> + /* Root bridge device needs to be sure of parent ACPI type */ >> + ACPI_COMPANION_SET(&device->dev, device); > > I do not understand why the code above is needed, can you elaborate > please ? > This makes sure that device->dev can be identified as ACPI device, so we can use to_acpi_device_node() and assign companion safely below. > >> + bus = pci_create_root_bus(&device->dev, busnum, ops->pci_ops, >> sysdata, &info->resources); >> if (!bus) >> goto out_release_info; >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c >> index 553a029..cad836f 100644 >> --- a/drivers/pci/probe.c >> +++ b/drivers/pci/probe.c >> @@ -2107,6 +2107,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, >> bridge->dev.parent = parent; >> bridge->dev.release = pci_release_host_bridge_dev; >> dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); >> + ACPI_COMPANION_SET(&bridge->dev, >> + parent ? to_acpi_device_node(parent->fwnode) : NULL); pci_create_root_bus() can be called with DT device, then ACPI_COMPANION_SET assign no companion to bridge device. Thanks, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jan 20, 2016 at 12:20:07PM +0100, Tomasz Nowicki wrote: > On 19.01.2016 17:02, Lorenzo Pieralisi wrote: > >On Wed, Jan 13, 2016 at 02:20:57PM +0100, Tomasz Nowicki wrote: > [...] > >>device via pci_create_root_bus parameter (as the ACPI device type) > > > >I do not understand what you mean by "as the ACPI device type". > > See below. > > > > >>and using ACPI_COMPANION_SET in core code for ACPI boot method. > >>ACPI_COMPANION_SET is safe to run for all cases DT, ACPI and DT&ACPI. > >> > >>Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > >>Signed-off-by: Tomasz Nowicki <tn@semihalf.com> > >>--- > >> drivers/acpi/pci_root.c | 5 ++++- > >> drivers/pci/probe.c | 2 ++ > >> 2 files changed, 6 insertions(+), 1 deletion(-) > >> > >>diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > >>index ae3fe4e..a65c8c2 100644 > >>--- a/drivers/acpi/pci_root.c > >>+++ b/drivers/acpi/pci_root.c > >>@@ -846,7 +846,10 @@ 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, > >>+ > >>+ /* Root bridge device needs to be sure of parent ACPI type */ > >>+ ACPI_COMPANION_SET(&device->dev, device); > > > >I do not understand why the code above is needed, can you elaborate > >please ? > > > > This makes sure that device->dev can be identified as ACPI device, > so we can use to_acpi_device_node() and assign companion safely > below. I do not follow. If you refer to the fwnode handle type, that is already set by ACPI core code (before acpi_pci_root_add() is called, in acpi_init_device_object()). Did you add the code above to solve a real issue you encountered ? Thanks, Lorenzo -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index ae3fe4e..a65c8c2 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -846,7 +846,10 @@ 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, + + /* Root bridge device needs to be sure of parent ACPI type */ + ACPI_COMPANION_SET(&device->dev, device); + bus = pci_create_root_bus(&device->dev, busnum, ops->pci_ops, sysdata, &info->resources); if (!bus) goto out_release_info; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 553a029..cad836f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2107,6 +2107,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, bridge->dev.parent = parent; bridge->dev.release = pci_release_host_bridge_dev; dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus); + ACPI_COMPANION_SET(&bridge->dev, + parent ? to_acpi_device_node(parent->fwnode) : NULL); error = pcibios_root_bridge_prepare(bridge); if (error) { kfree(bridge);
Currently we have two platforms (x86 & ia64) capable of PCI ACPI host bridge initialization. They both use sysdata pill to pass down parent device reference and both relay on NULL parent in pci_create_root_bus() to validate sysdata content. It looks hacky and prevent us from getting some frimware specific info for PCI host controller e.g. bus domain number. However, it seems we can overcome that blocker by passing down parent device via pci_create_root_bus parameter (as the ACPI device type) and using ACPI_COMPANION_SET in core code for ACPI boot method. ACPI_COMPANION_SET is safe to run for all cases DT, ACPI and DT&ACPI. Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Tomasz Nowicki <tn@semihalf.com> --- drivers/acpi/pci_root.c | 5 ++++- drivers/pci/probe.c | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-)