* [PATCH v2 0/3] arm/arm64: pci: PCI_PROBE_ONLY clean-up @ 2016-03-01 14:44 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel, linux-pci Cc: Lorenzo Pieralisi, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King Current arm/arm64 code prevents enabling resources in the respective pcibios_enable_device() callbacks if the PCI_PROBE_ONLY flag is set, in that on those platforms the resources tree was not validated properly since PCI resources are not currently claimed on arm/arm64 PCI_PROBE_ONLY systems. This is a temporary kludge, in that PCI_PROBE_ONLY flag is used to describe systems with fixed resources, that can nonetheless be enabled through the standard pci_enable_resources() call present in PCI core code, (ie via the generic pcibios_enable_device() call). To remove the PCI_PROBE_ONLY flag in arm/arm64 pcibios_enable_device() callbacks, the PCI host controllers that can be used with PCI_PROBE_ONLY configurations must make sure that devices resources are validated and inserted in the kernel resource tree even on PCI_PROBE_ONLY systems so that the generic pcibios_enable_device() generic code, while enabling resources (pci_enable_resources()), does not find dangling resources pointers (ie missing parent pointers) that are omens of an incomplete resource tree, causing failures in resources enablement. PCI core code provides interfaces to assign/reassign/reallocate PCI bus resources but it is currently lacking an interface to claim resources for a specific bus. Arches implement resources claiming through ad-hoc code built on top of pci_claim_resource() API, but that code cannot be leveraged on architectures like arm/arm64 that rely on the generic PCI infrastructure to carry out resources claiming/assignment. Therefore, to clean up the arm/arm64 resources enablement on PCI_PROBE_ONLY systems this patchset implements three patches: PATCH 1: Create PCI core code infrastructure to claim bus resources PATCH 2: Leverage the infrastructure in PATCH 1 to claim resources in the PCI generic host controller on PCI_PROBE_ONLY systems PATCH 3: Remove PCI_PROBE_ONLY kludges from arm/arm64 PCI back-ends to complete the clean-up and leverage the PCI generic pcibios_enable_device() implementation Tested on arm/arm64 systems with kvmtool and PCI host generic. v1 -> v2 - Rewrote patch 1 to recursively claim resources for the whole PCI bus hierarchy - Updated commits logs/tags - Rebased against v4.5-rc6 v1: https://patchwork.ozlabs.org/patch/545669/ Lorenzo Pieralisi (3): drivers: pci: add generic code to claim bus resources drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups arm/arm64: pci: remove arch specific pcibios_enable_device() arch/arm/kernel/bios32.c | 12 ------- arch/arm64/kernel/pci.c | 13 ------- drivers/pci/host/pci-host-generic.c | 5 ++- drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 5 files changed, 73 insertions(+), 26 deletions(-) -- 2.5.1 ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 0/3] arm/arm64: pci: PCI_PROBE_ONLY clean-up @ 2016-03-01 14:44 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel Current arm/arm64 code prevents enabling resources in the respective pcibios_enable_device() callbacks if the PCI_PROBE_ONLY flag is set, in that on those platforms the resources tree was not validated properly since PCI resources are not currently claimed on arm/arm64 PCI_PROBE_ONLY systems. This is a temporary kludge, in that PCI_PROBE_ONLY flag is used to describe systems with fixed resources, that can nonetheless be enabled through the standard pci_enable_resources() call present in PCI core code, (ie via the generic pcibios_enable_device() call). To remove the PCI_PROBE_ONLY flag in arm/arm64 pcibios_enable_device() callbacks, the PCI host controllers that can be used with PCI_PROBE_ONLY configurations must make sure that devices resources are validated and inserted in the kernel resource tree even on PCI_PROBE_ONLY systems so that the generic pcibios_enable_device() generic code, while enabling resources (pci_enable_resources()), does not find dangling resources pointers (ie missing parent pointers) that are omens of an incomplete resource tree, causing failures in resources enablement. PCI core code provides interfaces to assign/reassign/reallocate PCI bus resources but it is currently lacking an interface to claim resources for a specific bus. Arches implement resources claiming through ad-hoc code built on top of pci_claim_resource() API, but that code cannot be leveraged on architectures like arm/arm64 that rely on the generic PCI infrastructure to carry out resources claiming/assignment. Therefore, to clean up the arm/arm64 resources enablement on PCI_PROBE_ONLY systems this patchset implements three patches: PATCH 1: Create PCI core code infrastructure to claim bus resources PATCH 2: Leverage the infrastructure in PATCH 1 to claim resources in the PCI generic host controller on PCI_PROBE_ONLY systems PATCH 3: Remove PCI_PROBE_ONLY kludges from arm/arm64 PCI back-ends to complete the clean-up and leverage the PCI generic pcibios_enable_device() implementation Tested on arm/arm64 systems with kvmtool and PCI host generic. v1 -> v2 - Rewrote patch 1 to recursively claim resources for the whole PCI bus hierarchy - Updated commits logs/tags - Rebased against v4.5-rc6 v1: https://patchwork.ozlabs.org/patch/545669/ Lorenzo Pieralisi (3): drivers: pci: add generic code to claim bus resources drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups arm/arm64: pci: remove arch specific pcibios_enable_device() arch/arm/kernel/bios32.c | 12 ------- arch/arm64/kernel/pci.c | 13 ------- drivers/pci/host/pci-host-generic.c | 5 ++- drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 5 files changed, 73 insertions(+), 26 deletions(-) -- 2.5.1 ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 1/3] drivers: pci: add generic code to claim bus resources 2016-03-01 14:44 ` Lorenzo Pieralisi @ 2016-03-01 14:44 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel, linux-pci Cc: Lorenzo Pieralisi, Lorenzo Pieralisi, Arnd Bergmann, Bjorn Helgaas, Yinghai Lu, David Daney, Will Deacon, Catalin Marinas, Russell King From: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> PCI core code contains a set of functions, eg: pci_assign_unassigned_bus_resources() that allow to assign the PCI resources for a given bus after enumeration. On systems where the PCI BARs are immutable (ie they must not and can not be assigned), PCI bus resources should still be inserted in the PCI resources tree (even if they are not (re)-assigned), but there is no generic PCI kernel function for that purpose. Currently the PCI bus resources insertion in the resources tree is implemented in an arch specific fashion through arch specific callbacks that rely on the PCI resources claiming API (for bridges and devices) which resulted in arches implementations that contain duplicated code to claim resources for a given PCI bus hierarchy. This patch, based on the x86/ia64 resources claiming arch implementations, implements a set of functions in core PCI code that provides a PCI core interface for resources claiming for a given PCI bus hierarchy, paving the way for further resource claiming consolidation across architectures. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yinghai Lu <yinghai@kernel.org> --- drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 69 insertions(+) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 7796d0a..95f0906 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1424,6 +1424,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) } EXPORT_SYMBOL(pci_bus_assign_resources); +static void pci_claim_device_resources(struct pci_dev *dev) +{ + int i; + + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_resource(dev, i); + } +} + +static void pci_claim_bridge_resources(struct pci_dev *dev) +{ + int i; + + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_bridge_resource(dev, i); + } +} + +static void pci_bus_allocate_dev_resources(struct pci_bus *b) +{ + struct pci_dev *dev; + struct pci_bus *child; + + list_for_each_entry(dev, &b->devices, bus_list) { + pci_claim_device_resources(dev); + + child = dev->subordinate; + if (child) + pci_bus_allocate_dev_resources(child); + } +} + +static void pci_bus_allocate_resources(struct pci_bus *b) +{ + struct pci_bus *child; + + /* + * Carry out a depth-first search on the PCI bus + * tree to allocate bridge apertures. Read the + * programmed bridge bases and recursively claim + * the respective bridge resources. + */ + if (b->self) { + pci_read_bridge_bases(b); + pci_claim_bridge_resources(b->self); + } + + list_for_each_entry(child, &b->children, node) + pci_bus_allocate_resources(child); +} + +void pci_bus_claim_resources(struct pci_bus *b) +{ + pci_bus_allocate_resources(b); + pci_bus_allocate_dev_resources(b); +} +EXPORT_SYMBOL(pci_bus_claim_resources); + static void __pci_bridge_assign_resources(const struct pci_dev *bridge, struct list_head *add_head, struct list_head *fail_head) diff --git a/include/linux/pci.h b/include/linux/pci.h index 2771625..e66eba7 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1102,6 +1102,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); void pci_bus_assign_resources(const struct pci_bus *bus); +void pci_bus_claim_resources(struct pci_bus *bus); void pci_bus_size_bridges(struct pci_bus *bus); int pci_claim_resource(struct pci_dev *, int); int pci_claim_bridge_resource(struct pci_dev *bridge, int i); -- 2.5.1 ^ permalink raw reply related [flat|nested] 24+ messages in thread
* [PATCH v2 1/3] drivers: pci: add generic code to claim bus resources @ 2016-03-01 14:44 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel From: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> PCI core code contains a set of functions, eg: pci_assign_unassigned_bus_resources() that allow to assign the PCI resources for a given bus after enumeration. On systems where the PCI BARs are immutable (ie they must not and can not be assigned), PCI bus resources should still be inserted in the PCI resources tree (even if they are not (re)-assigned), but there is no generic PCI kernel function for that purpose. Currently the PCI bus resources insertion in the resources tree is implemented in an arch specific fashion through arch specific callbacks that rely on the PCI resources claiming API (for bridges and devices) which resulted in arches implementations that contain duplicated code to claim resources for a given PCI bus hierarchy. This patch, based on the x86/ia64 resources claiming arch implementations, implements a set of functions in core PCI code that provides a PCI core interface for resources claiming for a given PCI bus hierarchy, paving the way for further resource claiming consolidation across architectures. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Yinghai Lu <yinghai@kernel.org> --- drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 69 insertions(+) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 7796d0a..95f0906 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1424,6 +1424,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) } EXPORT_SYMBOL(pci_bus_assign_resources); +static void pci_claim_device_resources(struct pci_dev *dev) +{ + int i; + + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_resource(dev, i); + } +} + +static void pci_claim_bridge_resources(struct pci_dev *dev) +{ + int i; + + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_bridge_resource(dev, i); + } +} + +static void pci_bus_allocate_dev_resources(struct pci_bus *b) +{ + struct pci_dev *dev; + struct pci_bus *child; + + list_for_each_entry(dev, &b->devices, bus_list) { + pci_claim_device_resources(dev); + + child = dev->subordinate; + if (child) + pci_bus_allocate_dev_resources(child); + } +} + +static void pci_bus_allocate_resources(struct pci_bus *b) +{ + struct pci_bus *child; + + /* + * Carry out a depth-first search on the PCI bus + * tree to allocate bridge apertures. Read the + * programmed bridge bases and recursively claim + * the respective bridge resources. + */ + if (b->self) { + pci_read_bridge_bases(b); + pci_claim_bridge_resources(b->self); + } + + list_for_each_entry(child, &b->children, node) + pci_bus_allocate_resources(child); +} + +void pci_bus_claim_resources(struct pci_bus *b) +{ + pci_bus_allocate_resources(b); + pci_bus_allocate_dev_resources(b); +} +EXPORT_SYMBOL(pci_bus_claim_resources); + static void __pci_bridge_assign_resources(const struct pci_dev *bridge, struct list_head *add_head, struct list_head *fail_head) diff --git a/include/linux/pci.h b/include/linux/pci.h index 2771625..e66eba7 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1102,6 +1102,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); void pci_bus_assign_resources(const struct pci_bus *bus); +void pci_bus_claim_resources(struct pci_bus *bus); void pci_bus_size_bridges(struct pci_bus *bus); int pci_claim_resource(struct pci_dev *, int); int pci_claim_bridge_resource(struct pci_dev *bridge, int i); -- 2.5.1 ^ permalink raw reply related [flat|nested] 24+ messages in thread
* Re: [PATCH v2 1/3] drivers: pci: add generic code to claim bus resources 2016-03-01 14:44 ` Lorenzo Pieralisi @ 2016-04-26 12:47 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-26 12:47 UTC (permalink / raw) To: linux-arm-kernel, linux-pci Cc: Arnd Bergmann, Bjorn Helgaas, Yinghai Lu, David Daney, Will Deacon, Catalin Marinas, Russell King [Replying to self] On Tue, Mar 01, 2016 at 02:44:07PM +0000, Lorenzo Pieralisi wrote: > From: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> > > PCI core code contains a set of functions, eg: > > pci_assign_unassigned_bus_resources() > > that allow to assign the PCI resources for a given bus after > enumeration. > > On systems where the PCI BARs are immutable (ie they must not and can > not be assigned), PCI bus resources should still be inserted in the PCI > resources tree (even if they are not (re)-assigned), but there is > no generic PCI kernel function for that purpose. Currently the PCI bus > resources insertion in the resources tree is implemented in an arch > specific fashion through arch specific callbacks that rely on the PCI > resources claiming API (for bridges and devices) which resulted in arches > implementations that contain duplicated code to claim resources for a > given PCI bus hierarchy. > > This patch, based on the x86/ia64 resources claiming arch implementations, > implements a set of functions in core PCI code that provides a PCI core > interface for resources claiming for a given PCI bus hierarchy, paving > the way for further resource claiming consolidation across architectures. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Yinghai Lu <yinghai@kernel.org> > --- > drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 1 + > 2 files changed, 69 insertions(+) I have v3 ready, which does not change this patch, however I have some questions below before asking to merge it. > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 7796d0a..95f0906 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -1424,6 +1424,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) > } > EXPORT_SYMBOL(pci_bus_assign_resources); > > +static void pci_claim_device_resources(struct pci_dev *dev) > +{ > + int i; > + > + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { > + struct resource *r = &dev->resource[i]; > + > + if (!r->flags || r->parent) > + continue; > + > + pci_claim_resource(dev, i); pci_claim_resource() (and in particular pci_find_parent_resource()) fails if resource.start == 0x0. Is this intentional ? The resource.start == 0x0 check is used in other bits of the kernel to detect an "invalid" resource, I am not sure I understand its implications correctly. > + } > +} > + > +static void pci_claim_bridge_resources(struct pci_dev *dev) > +{ > + int i; > + > + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { > + struct resource *r = &dev->resource[i]; > + > + if (!r->flags || r->parent) > + continue; > + > + pci_claim_bridge_resource(dev, i); > + } > +} > + > +static void pci_bus_allocate_dev_resources(struct pci_bus *b) > +{ > + struct pci_dev *dev; > + struct pci_bus *child; > + > + list_for_each_entry(dev, &b->devices, bus_list) { > + pci_claim_device_resources(dev); > + > + child = dev->subordinate; > + if (child) > + pci_bus_allocate_dev_resources(child); > + } > +} > + > +static void pci_bus_allocate_resources(struct pci_bus *b) > +{ > + struct pci_bus *child; > + > + /* > + * Carry out a depth-first search on the PCI bus > + * tree to allocate bridge apertures. Read the > + * programmed bridge bases and recursively claim > + * the respective bridge resources. > + */ > + if (b->self) { Is it *always* correct to check b->self to detect a device backing the PCI bridge ? All PCI bridges should have their ->self pointer set-up correctly, I wanted to countercheck anyway. Comments welcome, thanks. Lorenzo > + pci_read_bridge_bases(b); > + pci_claim_bridge_resources(b->self); > + } > + > + list_for_each_entry(child, &b->children, node) > + pci_bus_allocate_resources(child); > +} > + > +void pci_bus_claim_resources(struct pci_bus *b) > +{ > + pci_bus_allocate_resources(b); > + pci_bus_allocate_dev_resources(b); > +} > +EXPORT_SYMBOL(pci_bus_claim_resources); > + > static void __pci_bridge_assign_resources(const struct pci_dev *bridge, > struct list_head *add_head, > struct list_head *fail_head) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 2771625..e66eba7 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1102,6 +1102,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void > /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ > resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); > void pci_bus_assign_resources(const struct pci_bus *bus); > +void pci_bus_claim_resources(struct pci_bus *bus); > void pci_bus_size_bridges(struct pci_bus *bus); > int pci_claim_resource(struct pci_dev *, int); > int pci_claim_bridge_resource(struct pci_dev *bridge, int i); > -- > 2.5.1 > ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 1/3] drivers: pci: add generic code to claim bus resources @ 2016-04-26 12:47 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-26 12:47 UTC (permalink / raw) To: linux-arm-kernel [Replying to self] On Tue, Mar 01, 2016 at 02:44:07PM +0000, Lorenzo Pieralisi wrote: > From: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> > > PCI core code contains a set of functions, eg: > > pci_assign_unassigned_bus_resources() > > that allow to assign the PCI resources for a given bus after > enumeration. > > On systems where the PCI BARs are immutable (ie they must not and can > not be assigned), PCI bus resources should still be inserted in the PCI > resources tree (even if they are not (re)-assigned), but there is > no generic PCI kernel function for that purpose. Currently the PCI bus > resources insertion in the resources tree is implemented in an arch > specific fashion through arch specific callbacks that rely on the PCI > resources claiming API (for bridges and devices) which resulted in arches > implementations that contain duplicated code to claim resources for a > given PCI bus hierarchy. > > This patch, based on the x86/ia64 resources claiming arch implementations, > implements a set of functions in core PCI code that provides a PCI core > interface for resources claiming for a given PCI bus hierarchy, paving > the way for further resource claiming consolidation across architectures. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Yinghai Lu <yinghai@kernel.org> > --- > drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 1 + > 2 files changed, 69 insertions(+) I have v3 ready, which does not change this patch, however I have some questions below before asking to merge it. > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 7796d0a..95f0906 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -1424,6 +1424,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) > } > EXPORT_SYMBOL(pci_bus_assign_resources); > > +static void pci_claim_device_resources(struct pci_dev *dev) > +{ > + int i; > + > + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { > + struct resource *r = &dev->resource[i]; > + > + if (!r->flags || r->parent) > + continue; > + > + pci_claim_resource(dev, i); pci_claim_resource() (and in particular pci_find_parent_resource()) fails if resource.start == 0x0. Is this intentional ? The resource.start == 0x0 check is used in other bits of the kernel to detect an "invalid" resource, I am not sure I understand its implications correctly. > + } > +} > + > +static void pci_claim_bridge_resources(struct pci_dev *dev) > +{ > + int i; > + > + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { > + struct resource *r = &dev->resource[i]; > + > + if (!r->flags || r->parent) > + continue; > + > + pci_claim_bridge_resource(dev, i); > + } > +} > + > +static void pci_bus_allocate_dev_resources(struct pci_bus *b) > +{ > + struct pci_dev *dev; > + struct pci_bus *child; > + > + list_for_each_entry(dev, &b->devices, bus_list) { > + pci_claim_device_resources(dev); > + > + child = dev->subordinate; > + if (child) > + pci_bus_allocate_dev_resources(child); > + } > +} > + > +static void pci_bus_allocate_resources(struct pci_bus *b) > +{ > + struct pci_bus *child; > + > + /* > + * Carry out a depth-first search on the PCI bus > + * tree to allocate bridge apertures. Read the > + * programmed bridge bases and recursively claim > + * the respective bridge resources. > + */ > + if (b->self) { Is it *always* correct to check b->self to detect a device backing the PCI bridge ? All PCI bridges should have their ->self pointer set-up correctly, I wanted to countercheck anyway. Comments welcome, thanks. Lorenzo > + pci_read_bridge_bases(b); > + pci_claim_bridge_resources(b->self); > + } > + > + list_for_each_entry(child, &b->children, node) > + pci_bus_allocate_resources(child); > +} > + > +void pci_bus_claim_resources(struct pci_bus *b) > +{ > + pci_bus_allocate_resources(b); > + pci_bus_allocate_dev_resources(b); > +} > +EXPORT_SYMBOL(pci_bus_claim_resources); > + > static void __pci_bridge_assign_resources(const struct pci_dev *bridge, > struct list_head *add_head, > struct list_head *fail_head) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 2771625..e66eba7 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1102,6 +1102,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void > /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ > resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); > void pci_bus_assign_resources(const struct pci_bus *bus); > +void pci_bus_claim_resources(struct pci_bus *bus); > void pci_bus_size_bridges(struct pci_bus *bus); > int pci_claim_resource(struct pci_dev *, int); > int pci_claim_bridge_resource(struct pci_dev *bridge, int i); > -- > 2.5.1 > ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-03-01 14:44 ` Lorenzo Pieralisi @ 2016-03-01 14:44 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel, linux-pci Cc: Lorenzo Pieralisi, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King The PCI host generic driver does not reassign bus resources on systems that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since that would trigger system failures. Nonetheless, PCI bus resources allocated to PCI bridge and devices must be claimed in order to be validated and inserted in the kernel resource tree, but the current driver omits the resources claiming and relies on arch specific kludges to prevent probing failure (ie preventing resources enablement on PCI_PROBE_ONLY systems). This patch adds code to the PCI host generic driver that correctly claims bus resources upon probe on systems that are required to prevent reassignment after bus enumeration, so that the allocated resources can be enabled successfully upon PCI device drivers probing, without resorting to arch back-ends workarounds. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Daney <david.daney@cavium.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> --- drivers/pci/host/pci-host-generic.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index 1652bc7..e529825 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); - if (!pci_has_flag(PCI_PROBE_ONLY)) { + + if (pci_has_flag(PCI_PROBE_ONLY)) { + pci_bus_claim_resources(bus); + } else { pci_bus_size_bridges(bus); pci_bus_assign_resources(bus); -- 2.5.1 ^ permalink raw reply related [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-03-01 14:44 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel The PCI host generic driver does not reassign bus resources on systems that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since that would trigger system failures. Nonetheless, PCI bus resources allocated to PCI bridge and devices must be claimed in order to be validated and inserted in the kernel resource tree, but the current driver omits the resources claiming and relies on arch specific kludges to prevent probing failure (ie preventing resources enablement on PCI_PROBE_ONLY systems). This patch adds code to the PCI host generic driver that correctly claims bus resources upon probe on systems that are required to prevent reassignment after bus enumeration, so that the allocated resources can be enabled successfully upon PCI device drivers probing, without resorting to arch back-ends workarounds. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Daney <david.daney@cavium.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> --- drivers/pci/host/pci-host-generic.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c index 1652bc7..e529825 100644 --- a/drivers/pci/host/pci-host-generic.c +++ b/drivers/pci/host/pci-host-generic.c @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); - if (!pci_has_flag(PCI_PROBE_ONLY)) { + + if (pci_has_flag(PCI_PROBE_ONLY)) { + pci_bus_claim_resources(bus); + } else { pci_bus_size_bridges(bus); pci_bus_assign_resources(bus); -- 2.5.1 ^ permalink raw reply related [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-03-01 14:44 ` Lorenzo Pieralisi @ 2016-04-12 4:43 ` Bjorn Helgaas -1 siblings, 0 replies; 24+ messages in thread From: Bjorn Helgaas @ 2016-04-12 4:43 UTC (permalink / raw) To: Lorenzo Pieralisi Cc: linux-arm-kernel, linux-pci, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King Hi Lorenzo, On Tue, Mar 01, 2016 at 02:44:08PM +0000, Lorenzo Pieralisi wrote: > The PCI host generic driver does not reassign bus resources on systems > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > that would trigger system failures. Nonetheless, PCI bus resources > allocated to PCI bridge and devices must be claimed in order to be > validated and inserted in the kernel resource tree, but the current > driver omits the resources claiming and relies on arch specific kludges > to prevent probing failure (ie preventing resources enablement on > PCI_PROBE_ONLY systems). > > This patch adds code to the PCI host generic driver that correctly > claims bus resources upon probe on systems that are required to > prevent reassignment after bus enumeration, so that the allocated > resources can be enabled successfully upon PCI device drivers probing, > without resorting to arch back-ends workarounds. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Acked-by: Will Deacon <will.deacon@arm.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: David Daney <david.daney@cavium.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> > --- > drivers/pci/host/pci-host-generic.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > index 1652bc7..e529825 100644 > --- a/drivers/pci/host/pci-host-generic.c > +++ b/drivers/pci/host/pci-host-generic.c > @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > + > + if (pci_has_flag(PCI_PROBE_ONLY)) { > + pci_bus_claim_resources(bus); > + } else { > pci_bus_size_bridges(bus); > pci_bus_assign_resources(bus); > The next patch removes the arm and arm64 pcibios_enable_device() implementations, which implies that arm and arm64 only need the generic version, which simply calls pci_enable_resources(). That assumes r->parent is set. After this patch, we'll call pci_bus_claim_resources() for the PCI_PROBE_ONLY case, and that sets r->parent for all the resources. Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously that path *works*, because you're not changing anything there. I'd just like to have a hint that makes this change more obvious. Bjorn ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-12 4:43 ` Bjorn Helgaas 0 siblings, 0 replies; 24+ messages in thread From: Bjorn Helgaas @ 2016-04-12 4:43 UTC (permalink / raw) To: linux-arm-kernel Hi Lorenzo, On Tue, Mar 01, 2016 at 02:44:08PM +0000, Lorenzo Pieralisi wrote: > The PCI host generic driver does not reassign bus resources on systems > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > that would trigger system failures. Nonetheless, PCI bus resources > allocated to PCI bridge and devices must be claimed in order to be > validated and inserted in the kernel resource tree, but the current > driver omits the resources claiming and relies on arch specific kludges > to prevent probing failure (ie preventing resources enablement on > PCI_PROBE_ONLY systems). > > This patch adds code to the PCI host generic driver that correctly > claims bus resources upon probe on systems that are required to > prevent reassignment after bus enumeration, so that the allocated > resources can be enabled successfully upon PCI device drivers probing, > without resorting to arch back-ends workarounds. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Acked-by: Will Deacon <will.deacon@arm.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: David Daney <david.daney@cavium.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Bjorn Helgaas <bhelgaas@google.com> > --- > drivers/pci/host/pci-host-generic.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > index 1652bc7..e529825 100644 > --- a/drivers/pci/host/pci-host-generic.c > +++ b/drivers/pci/host/pci-host-generic.c > @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > + > + if (pci_has_flag(PCI_PROBE_ONLY)) { > + pci_bus_claim_resources(bus); > + } else { > pci_bus_size_bridges(bus); > pci_bus_assign_resources(bus); > The next patch removes the arm and arm64 pcibios_enable_device() implementations, which implies that arm and arm64 only need the generic version, which simply calls pci_enable_resources(). That assumes r->parent is set. After this patch, we'll call pci_bus_claim_resources() for the PCI_PROBE_ONLY case, and that sets r->parent for all the resources. Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously that path *works*, because you're not changing anything there. I'd just like to have a hint that makes this change more obvious. Bjorn ^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-04-12 4:43 ` Bjorn Helgaas @ 2016-04-12 15:48 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-12 15:48 UTC (permalink / raw) To: Bjorn Helgaas Cc: linux-arm-kernel, linux-pci, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King On Mon, Apr 11, 2016 at 11:43:11PM -0500, Bjorn Helgaas wrote: > Hi Lorenzo, > > On Tue, Mar 01, 2016 at 02:44:08PM +0000, Lorenzo Pieralisi wrote: > > The PCI host generic driver does not reassign bus resources on systems > > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > > that would trigger system failures. Nonetheless, PCI bus resources > > allocated to PCI bridge and devices must be claimed in order to be > > validated and inserted in the kernel resource tree, but the current > > driver omits the resources claiming and relies on arch specific kludges > > to prevent probing failure (ie preventing resources enablement on > > PCI_PROBE_ONLY systems). > > > > This patch adds code to the PCI host generic driver that correctly > > claims bus resources upon probe on systems that are required to > > prevent reassignment after bus enumeration, so that the allocated > > resources can be enabled successfully upon PCI device drivers probing, > > without resorting to arch back-ends workarounds. > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Acked-by: Will Deacon <will.deacon@arm.com> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: David Daney <david.daney@cavium.com> > > Cc: Will Deacon <will.deacon@arm.com> > > Cc: Bjorn Helgaas <bhelgaas@google.com> > > --- > > drivers/pci/host/pci-host-generic.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > > index 1652bc7..e529825 100644 > > --- a/drivers/pci/host/pci-host-generic.c > > +++ b/drivers/pci/host/pci-host-generic.c > > @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > > + > > + if (pci_has_flag(PCI_PROBE_ONLY)) { > > + pci_bus_claim_resources(bus); > > + } else { > > pci_bus_size_bridges(bus); > > pci_bus_assign_resources(bus); > > > > The next patch removes the arm and arm64 pcibios_enable_device() > implementations, which implies that arm and arm64 only need the generic > version, which simply calls pci_enable_resources(). That assumes r->parent > is set. > > After this patch, we'll call pci_bus_claim_resources() for the > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > that path *works*, because you're not changing anything there. I'd just > like to have a hint that makes this change more obvious. On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need this patch), resources are always reassigned and the core code reassigning them takes care of assigning their parent pointers too, to answer your question. As for this patch series, given that: commit (in -next) 903589ca7165 ("ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling") removes the PCI_PROBE_ONLY handling from the (ARM) command line, the PCI host generic becomes the last ARM/ARM64 host controller that requires PCI_PROBE_ONLY to function (depending on DT settings). The idea behind adding pci_bus_claim_resources (patch 1) to core code was that it could be reused by other arches too, I do not have evidence though, I have to prove it, so I'd rather squash patch 1 into this one and make the code claiming resources local to the PCI host generic, I can't add a generic PCI core API just for one host controller (IMHO we should add an API that allows us to claim bus resources and realloc the ones for which claiming fail - which may mean releasing bridges resources and realloc/resize them - code is in the kernel already I have to write that API). The code claiming resources on x86, IA64 and PowerPC looks extremely similar but it has to be proven that a generic function has a chance to work, so patch 1 is not really justified at present. If you have no objections I will squash patch 1 into this one (moving the respective code in PCI host generic driver), and I would not merge this series till the commit above in -next gets in the kernel (which makes sure that PCI_PROBE_ONLY can't be set on the command line, that's fundamental to this series, at least on ARM, on ARM64 DT is the only way PCI_PROBE_ONLY can be set and only on host controllers that check the chosen node property - ie PCI host generic, that we are patching). Thanks, Lorenzo ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-12 15:48 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-12 15:48 UTC (permalink / raw) To: linux-arm-kernel On Mon, Apr 11, 2016 at 11:43:11PM -0500, Bjorn Helgaas wrote: > Hi Lorenzo, > > On Tue, Mar 01, 2016 at 02:44:08PM +0000, Lorenzo Pieralisi wrote: > > The PCI host generic driver does not reassign bus resources on systems > > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > > that would trigger system failures. Nonetheless, PCI bus resources > > allocated to PCI bridge and devices must be claimed in order to be > > validated and inserted in the kernel resource tree, but the current > > driver omits the resources claiming and relies on arch specific kludges > > to prevent probing failure (ie preventing resources enablement on > > PCI_PROBE_ONLY systems). > > > > This patch adds code to the PCI host generic driver that correctly > > claims bus resources upon probe on systems that are required to > > prevent reassignment after bus enumeration, so that the allocated > > resources can be enabled successfully upon PCI device drivers probing, > > without resorting to arch back-ends workarounds. > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Acked-by: Will Deacon <will.deacon@arm.com> > > Cc: Arnd Bergmann <arnd@arndb.de> > > Cc: David Daney <david.daney@cavium.com> > > Cc: Will Deacon <will.deacon@arm.com> > > Cc: Bjorn Helgaas <bhelgaas@google.com> > > --- > > drivers/pci/host/pci-host-generic.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > > index 1652bc7..e529825 100644 > > --- a/drivers/pci/host/pci-host-generic.c > > +++ b/drivers/pci/host/pci-host-generic.c > > @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > > + > > + if (pci_has_flag(PCI_PROBE_ONLY)) { > > + pci_bus_claim_resources(bus); > > + } else { > > pci_bus_size_bridges(bus); > > pci_bus_assign_resources(bus); > > > > The next patch removes the arm and arm64 pcibios_enable_device() > implementations, which implies that arm and arm64 only need the generic > version, which simply calls pci_enable_resources(). That assumes r->parent > is set. > > After this patch, we'll call pci_bus_claim_resources() for the > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > that path *works*, because you're not changing anything there. I'd just > like to have a hint that makes this change more obvious. On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need this patch), resources are always reassigned and the core code reassigning them takes care of assigning their parent pointers too, to answer your question. As for this patch series, given that: commit (in -next) 903589ca7165 ("ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling") removes the PCI_PROBE_ONLY handling from the (ARM) command line, the PCI host generic becomes the last ARM/ARM64 host controller that requires PCI_PROBE_ONLY to function (depending on DT settings). The idea behind adding pci_bus_claim_resources (patch 1) to core code was that it could be reused by other arches too, I do not have evidence though, I have to prove it, so I'd rather squash patch 1 into this one and make the code claiming resources local to the PCI host generic, I can't add a generic PCI core API just for one host controller (IMHO we should add an API that allows us to claim bus resources and realloc the ones for which claiming fail - which may mean releasing bridges resources and realloc/resize them - code is in the kernel already I have to write that API). The code claiming resources on x86, IA64 and PowerPC looks extremely similar but it has to be proven that a generic function has a chance to work, so patch 1 is not really justified at present. If you have no objections I will squash patch 1 into this one (moving the respective code in PCI host generic driver), and I would not merge this series till the commit above in -next gets in the kernel (which makes sure that PCI_PROBE_ONLY can't be set on the command line, that's fundamental to this series, at least on ARM, on ARM64 DT is the only way PCI_PROBE_ONLY can be set and only on host controllers that check the chosen node property - ie PCI host generic, that we are patching). Thanks, Lorenzo ^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-04-12 15:48 ` Lorenzo Pieralisi @ 2016-04-15 13:08 ` Bjorn Helgaas -1 siblings, 0 replies; 24+ messages in thread From: Bjorn Helgaas @ 2016-04-15 13:08 UTC (permalink / raw) To: Lorenzo Pieralisi Cc: linux-arm-kernel, linux-pci, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > On Mon, Apr 11, 2016 at 11:43:11PM -0500, Bjorn Helgaas wrote: > > Hi Lorenzo, > > > > On Tue, Mar 01, 2016 at 02:44:08PM +0000, Lorenzo Pieralisi wrote: > > > The PCI host generic driver does not reassign bus resources on systems > > > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > > > that would trigger system failures. Nonetheless, PCI bus resources > > > allocated to PCI bridge and devices must be claimed in order to be > > > validated and inserted in the kernel resource tree, but the current > > > driver omits the resources claiming and relies on arch specific kludges > > > to prevent probing failure (ie preventing resources enablement on > > > PCI_PROBE_ONLY systems). > > > > > > This patch adds code to the PCI host generic driver that correctly > > > claims bus resources upon probe on systems that are required to > > > prevent reassignment after bus enumeration, so that the allocated > > > resources can be enabled successfully upon PCI device drivers probing, > > > without resorting to arch back-ends workarounds. > > > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > > Acked-by: Will Deacon <will.deacon@arm.com> > > > Cc: Arnd Bergmann <arnd@arndb.de> > > > Cc: David Daney <david.daney@cavium.com> > > > Cc: Will Deacon <will.deacon@arm.com> > > > Cc: Bjorn Helgaas <bhelgaas@google.com> > > > --- > > > drivers/pci/host/pci-host-generic.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > > > index 1652bc7..e529825 100644 > > > --- a/drivers/pci/host/pci-host-generic.c > > > +++ b/drivers/pci/host/pci-host-generic.c > > > @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > > > > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > > > > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > > > + > > > + if (pci_has_flag(PCI_PROBE_ONLY)) { > > > + pci_bus_claim_resources(bus); > > > + } else { > > > pci_bus_size_bridges(bus); > > > pci_bus_assign_resources(bus); > > > > > > > The next patch removes the arm and arm64 pcibios_enable_device() > > implementations, which implies that arm and arm64 only need the generic > > version, which simply calls pci_enable_resources(). That assumes r->parent > > is set. > > > > After this patch, we'll call pci_bus_claim_resources() for the > > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > > that path *works*, because you're not changing anything there. I'd just > > like to have a hint that makes this change more obvious. > > On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the > kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need > this patch), resources are always reassigned and the core code reassigning > them takes care of assigning their parent pointers too, to answer your > question. Here's what I find confusing. Consider these three cases: 1) Firmware programs no BARs and we reassign everything. We call pci_bus_assign_resources(), and the pci_assign_resource() ... allocate_resource() path makes sure everything is claimed. This is apparently the normal arm/arm64 path, and it already works. 2) Firmware programs all BARs and we set PCI_PROBE_ONLY. After this series, we'll claim the resources and remove the PCI_PROBE_ONLY special case in pcibios_enable_device(). This is great! 3) Firmware programs all BARs but we don't set PCI_PROBE_ONLY. We call pci_bus_assign_resources(), but I think it does nothing because everything is already assigned. The resources are not claimed and pci_enable_resources() will fail. This last case 3) is the problem. I'm guessing this case doesn't currently occur on arm/arm64, but it's the normal case on x86, and it seems perverse that things work if firmware does nothing, but they don't work if firmware does more setup. So I think we should add some sort of arm/arm64-specific pci_claim_resource() path similar to the pcibios_allocate_resources() stuff on x86. > As for this patch series, given that: > > commit (in -next) 903589ca7165 ("ARM: 8554/1: kernel: pci: remove > pci=firmware command line parameter handling") removes the PCI_PROBE_ONLY > handling from the (ARM) command line, the PCI host generic becomes the > last ARM/ARM64 host controller that requires PCI_PROBE_ONLY to function > (depending on DT settings). > > The idea behind adding pci_bus_claim_resources (patch 1) to core code > was that it could be reused by other arches too, I do not have evidence > though, I have to prove it, so I'd rather squash patch 1 into this one > and make the code claiming resources local to the PCI host generic, > I can't add a generic PCI core API just for one host controller > (IMHO we should add an API that allows us to claim bus resources and > realloc the ones for which claiming fail - which may mean releasing > bridges resources and realloc/resize them - code is in the kernel already > I have to write that API). > > The code claiming resources on x86, IA64 and PowerPC looks extremely > similar but it has to be proven that a generic function has a chance > to work, so patch 1 is not really justified at present. I don't really object to patch 1, but you're right that it's possible we could do a better job later. I would certainly like to get that sort of code (including the pcibios_allocate_resources() stuff I just mentioned) out of the arches and into the core somehow. > If you have no objections I will squash patch 1 into this one (moving > the respective code in PCI host generic driver), and I would not merge > this series till the commit above in -next gets in the kernel (which > makes sure that PCI_PROBE_ONLY can't be set on the command line, that's > fundamental to this series, at least on ARM, on ARM64 DT is the only way > PCI_PROBE_ONLY can be set and only on host controllers that check the > chosen node property - ie PCI host generic, that we are patching). If there's a stable branch containing 903589ca7165 ("ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling"), I can pull that and merge your series on top of it. Bjorn ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-15 13:08 ` Bjorn Helgaas 0 siblings, 0 replies; 24+ messages in thread From: Bjorn Helgaas @ 2016-04-15 13:08 UTC (permalink / raw) To: linux-arm-kernel On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > On Mon, Apr 11, 2016 at 11:43:11PM -0500, Bjorn Helgaas wrote: > > Hi Lorenzo, > > > > On Tue, Mar 01, 2016 at 02:44:08PM +0000, Lorenzo Pieralisi wrote: > > > The PCI host generic driver does not reassign bus resources on systems > > > that require the BARs set-up to be immutable (ie PCI_PROBE_ONLY) since > > > that would trigger system failures. Nonetheless, PCI bus resources > > > allocated to PCI bridge and devices must be claimed in order to be > > > validated and inserted in the kernel resource tree, but the current > > > driver omits the resources claiming and relies on arch specific kludges > > > to prevent probing failure (ie preventing resources enablement on > > > PCI_PROBE_ONLY systems). > > > > > > This patch adds code to the PCI host generic driver that correctly > > > claims bus resources upon probe on systems that are required to > > > prevent reassignment after bus enumeration, so that the allocated > > > resources can be enabled successfully upon PCI device drivers probing, > > > without resorting to arch back-ends workarounds. > > > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > > Acked-by: Will Deacon <will.deacon@arm.com> > > > Cc: Arnd Bergmann <arnd@arndb.de> > > > Cc: David Daney <david.daney@cavium.com> > > > Cc: Will Deacon <will.deacon@arm.com> > > > Cc: Bjorn Helgaas <bhelgaas@google.com> > > > --- > > > drivers/pci/host/pci-host-generic.c | 5 ++++- > > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/pci/host/pci-host-generic.c b/drivers/pci/host/pci-host-generic.c > > > index 1652bc7..e529825 100644 > > > --- a/drivers/pci/host/pci-host-generic.c > > > +++ b/drivers/pci/host/pci-host-generic.c > > > @@ -252,7 +252,10 @@ static int gen_pci_probe(struct platform_device *pdev) > > > > > > pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci); > > > > > > - if (!pci_has_flag(PCI_PROBE_ONLY)) { > > > + > > > + if (pci_has_flag(PCI_PROBE_ONLY)) { > > > + pci_bus_claim_resources(bus); > > > + } else { > > > pci_bus_size_bridges(bus); > > > pci_bus_assign_resources(bus); > > > > > > > The next patch removes the arm and arm64 pcibios_enable_device() > > implementations, which implies that arm and arm64 only need the generic > > version, which simply calls pci_enable_resources(). That assumes r->parent > > is set. > > > > After this patch, we'll call pci_bus_claim_resources() for the > > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > > that path *works*, because you're not changing anything there. I'd just > > like to have a hint that makes this change more obvious. > > On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the > kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need > this patch), resources are always reassigned and the core code reassigning > them takes care of assigning their parent pointers too, to answer your > question. Here's what I find confusing. Consider these three cases: 1) Firmware programs no BARs and we reassign everything. We call pci_bus_assign_resources(), and the pci_assign_resource() ... allocate_resource() path makes sure everything is claimed. This is apparently the normal arm/arm64 path, and it already works. 2) Firmware programs all BARs and we set PCI_PROBE_ONLY. After this series, we'll claim the resources and remove the PCI_PROBE_ONLY special case in pcibios_enable_device(). This is great! 3) Firmware programs all BARs but we don't set PCI_PROBE_ONLY. We call pci_bus_assign_resources(), but I think it does nothing because everything is already assigned. The resources are not claimed and pci_enable_resources() will fail. This last case 3) is the problem. I'm guessing this case doesn't currently occur on arm/arm64, but it's the normal case on x86, and it seems perverse that things work if firmware does nothing, but they don't work if firmware does more setup. So I think we should add some sort of arm/arm64-specific pci_claim_resource() path similar to the pcibios_allocate_resources() stuff on x86. > As for this patch series, given that: > > commit (in -next) 903589ca7165 ("ARM: 8554/1: kernel: pci: remove > pci=firmware command line parameter handling") removes the PCI_PROBE_ONLY > handling from the (ARM) command line, the PCI host generic becomes the > last ARM/ARM64 host controller that requires PCI_PROBE_ONLY to function > (depending on DT settings). > > The idea behind adding pci_bus_claim_resources (patch 1) to core code > was that it could be reused by other arches too, I do not have evidence > though, I have to prove it, so I'd rather squash patch 1 into this one > and make the code claiming resources local to the PCI host generic, > I can't add a generic PCI core API just for one host controller > (IMHO we should add an API that allows us to claim bus resources and > realloc the ones for which claiming fail - which may mean releasing > bridges resources and realloc/resize them - code is in the kernel already > I have to write that API). > > The code claiming resources on x86, IA64 and PowerPC looks extremely > similar but it has to be proven that a generic function has a chance > to work, so patch 1 is not really justified at present. I don't really object to patch 1, but you're right that it's possible we could do a better job later. I would certainly like to get that sort of code (including the pcibios_allocate_resources() stuff I just mentioned) out of the arches and into the core somehow. > If you have no objections I will squash patch 1 into this one (moving > the respective code in PCI host generic driver), and I would not merge > this series till the commit above in -next gets in the kernel (which > makes sure that PCI_PROBE_ONLY can't be set on the command line, that's > fundamental to this series, at least on ARM, on ARM64 DT is the only way > PCI_PROBE_ONLY can be set and only on host controllers that check the > chosen node property - ie PCI host generic, that we are patching). If there's a stable branch containing 903589ca7165 ("ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling"), I can pull that and merge your series on top of it. Bjorn ^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-04-15 13:08 ` Bjorn Helgaas @ 2016-04-18 10:01 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-18 10:01 UTC (permalink / raw) To: Bjorn Helgaas Cc: linux-arm-kernel, linux-pci, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: [...] > > > The next patch removes the arm and arm64 pcibios_enable_device() > > > implementations, which implies that arm and arm64 only need the generic > > > version, which simply calls pci_enable_resources(). That assumes r->parent > > > is set. > > > > > > After this patch, we'll call pci_bus_claim_resources() for the > > > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > > > > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > > > that path *works*, because you're not changing anything there. I'd just > > > like to have a hint that makes this change more obvious. > > > > On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the > > kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need > > this patch), resources are always reassigned and the core code reassigning > > them takes care of assigning their parent pointers too, to answer your > > question. > > Here's what I find confusing. Consider these three cases: > > 1) Firmware programs no BARs and we reassign everything. We call > pci_bus_assign_resources(), and the pci_assign_resource() ... > allocate_resource() path makes sure everything is claimed. This is > apparently the normal arm/arm64 path, and it already works. > > 2) Firmware programs all BARs and we set PCI_PROBE_ONLY. After this > series, we'll claim the resources and remove the PCI_PROBE_ONLY > special case in pcibios_enable_device(). This is great! > > 3) Firmware programs all BARs but we don't set PCI_PROBE_ONLY. We > call pci_bus_assign_resources(), but I think it does nothing because > everything is already assigned. The resources are not claimed and > pci_enable_resources() will fail. I do not expect (1) and (3) to be different from a kernel resource allocation perspective. If the core resource layer is asked to assign resources it will, regardless of what FW programmed in the BARs (the BAR regions size matters, that's it), I went through pci_bus_assign_resources() a couple of times and I have to add a bit of debugging so give me the benefit of the doubt please, but there is nothing that let me think it won't assign resources (and therefore assign a parent pointer) if the resources are already programmed correctly (actually I even think the kernel may change what FW programmed according to its resource alloc policy). > This last case 3) is the problem. I'm guessing this case doesn't > currently occur on arm/arm64, but it's the normal case on x86, and it > seems perverse that things work if firmware does nothing, but they > don't work if firmware does more setup. IIUC X86 claim resources as programmed by FW so it is not really the same situation as arm64, that claims nothing. Claimed resources are not reassigned, they are skipped by resource allocation/sizing code (because their parent pointer is set). And as I said above even if FW does some set-up that will still work on ARM/ARM64, otherwise this means that on ALL ARM/ARM64 systems out there PCI set-up at kernel handover is non-existent, otherwise we would have resource enablement failures NOW, right ? > So I think we should add some sort of arm/arm64-specific > pci_claim_resource() path similar to the pcibios_allocate_resources() > stuff on x86. I agree but it has to be done with care in particular in relation to bridges apertures, claiming resources on systems that currently reassign everything may trigger regressions. In particular, having an API that claims resources is NOT sufficient for that purpose for two reasons: - If resource claiming fails for some resources, currently the kernel spits too much noise in the logs, claiming should be a best-effort approach, if it fails there is no error to report in the logs, if FW left resources unset that's *not* an error AFAIK - Bridge apertures: care must be taken so that resources downstream should be sized so that bridges can accomodate them, this may require releasing previously claimed bridge apertures and realloc them The approach should be: (1) Claim resources (2) Realloc whatever fails (which may imply releasing bridges resources previously claimed) > > As for this patch series, given that: > > > > commit (in -next) 903589ca7165 ("ARM: 8554/1: kernel: pci: remove > > pci=firmware command line parameter handling") removes the PCI_PROBE_ONLY > > handling from the (ARM) command line, the PCI host generic becomes the > > last ARM/ARM64 host controller that requires PCI_PROBE_ONLY to function > > (depending on DT settings). > > > > The idea behind adding pci_bus_claim_resources (patch 1) to core code > > was that it could be reused by other arches too, I do not have evidence > > though, I have to prove it, so I'd rather squash patch 1 into this one > > and make the code claiming resources local to the PCI host generic, > > I can't add a generic PCI core API just for one host controller > > (IMHO we should add an API that allows us to claim bus resources and > > realloc the ones for which claiming fail - which may mean releasing > > bridges resources and realloc/resize them - code is in the kernel already > > I have to write that API). > > > > The code claiming resources on x86, IA64 and PowerPC looks extremely > > similar but it has to be proven that a generic function has a chance > > to work, so patch 1 is not really justified at present. > > I don't really object to patch 1, but you're right that it's possible > we could do a better job later. I would certainly like to get that > sort of code (including the pcibios_allocate_resources() stuff I just > mentioned) out of the arches and into the core somehow. Problem with patch 1, is that, if resource claiming fails, it spits loads of noise in kernel logs (actually it is pci_claim_resource(), that patch 1 uses, that spits errors on claiming failure), that's a detail but it will make people unhappy. I do not think that if claiming for a particular resource fails we can consider it an error that's why I see patch 1 more PCI host generic PCI_PROBE_ONLY specific rather than anything else, we can't use it for !PCI_PROBE_ONLY systems unless I rework it to remove the kernel error logs on resource claiming failures. Probably on X86/IA64 resource claiming is spotless because on most if not all systems FW programmes the PCI bus and the kernel can take the set-up as-is, it is a question since I have no visibility into that. > > If you have no objections I will squash patch 1 into this one (moving > > the respective code in PCI host generic driver), and I would not merge > > this series till the commit above in -next gets in the kernel (which > > makes sure that PCI_PROBE_ONLY can't be set on the command line, that's > > fundamental to this series, at least on ARM, on ARM64 DT is the only way > > PCI_PROBE_ONLY can be set and only on host controllers that check the > > chosen node property - ie PCI host generic, that we are patching). > > If there's a stable branch containing 903589ca7165 ("ARM: 8554/1: > kernel: pci: remove pci=firmware command line parameter handling"), I > can pull that and merge your series on top of it. I think I should at least split patch 3 in two (one for ARM and one for ARM64), if Russell is forced to revert the commit above (because we discover pci=firmware command line users) I do not want ARM64 to be affected. Thanks ! Lorenzo ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-18 10:01 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-18 10:01 UTC (permalink / raw) To: linux-arm-kernel On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: [...] > > > The next patch removes the arm and arm64 pcibios_enable_device() > > > implementations, which implies that arm and arm64 only need the generic > > > version, which simply calls pci_enable_resources(). That assumes r->parent > > > is set. > > > > > > After this patch, we'll call pci_bus_claim_resources() for the > > > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > > > > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > > > that path *works*, because you're not changing anything there. I'd just > > > like to have a hint that makes this change more obvious. > > > > On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the > > kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need > > this patch), resources are always reassigned and the core code reassigning > > them takes care of assigning their parent pointers too, to answer your > > question. > > Here's what I find confusing. Consider these three cases: > > 1) Firmware programs no BARs and we reassign everything. We call > pci_bus_assign_resources(), and the pci_assign_resource() ... > allocate_resource() path makes sure everything is claimed. This is > apparently the normal arm/arm64 path, and it already works. > > 2) Firmware programs all BARs and we set PCI_PROBE_ONLY. After this > series, we'll claim the resources and remove the PCI_PROBE_ONLY > special case in pcibios_enable_device(). This is great! > > 3) Firmware programs all BARs but we don't set PCI_PROBE_ONLY. We > call pci_bus_assign_resources(), but I think it does nothing because > everything is already assigned. The resources are not claimed and > pci_enable_resources() will fail. I do not expect (1) and (3) to be different from a kernel resource allocation perspective. If the core resource layer is asked to assign resources it will, regardless of what FW programmed in the BARs (the BAR regions size matters, that's it), I went through pci_bus_assign_resources() a couple of times and I have to add a bit of debugging so give me the benefit of the doubt please, but there is nothing that let me think it won't assign resources (and therefore assign a parent pointer) if the resources are already programmed correctly (actually I even think the kernel may change what FW programmed according to its resource alloc policy). > This last case 3) is the problem. I'm guessing this case doesn't > currently occur on arm/arm64, but it's the normal case on x86, and it > seems perverse that things work if firmware does nothing, but they > don't work if firmware does more setup. IIUC X86 claim resources as programmed by FW so it is not really the same situation as arm64, that claims nothing. Claimed resources are not reassigned, they are skipped by resource allocation/sizing code (because their parent pointer is set). And as I said above even if FW does some set-up that will still work on ARM/ARM64, otherwise this means that on ALL ARM/ARM64 systems out there PCI set-up at kernel handover is non-existent, otherwise we would have resource enablement failures NOW, right ? > So I think we should add some sort of arm/arm64-specific > pci_claim_resource() path similar to the pcibios_allocate_resources() > stuff on x86. I agree but it has to be done with care in particular in relation to bridges apertures, claiming resources on systems that currently reassign everything may trigger regressions. In particular, having an API that claims resources is NOT sufficient for that purpose for two reasons: - If resource claiming fails for some resources, currently the kernel spits too much noise in the logs, claiming should be a best-effort approach, if it fails there is no error to report in the logs, if FW left resources unset that's *not* an error AFAIK - Bridge apertures: care must be taken so that resources downstream should be sized so that bridges can accomodate them, this may require releasing previously claimed bridge apertures and realloc them The approach should be: (1) Claim resources (2) Realloc whatever fails (which may imply releasing bridges resources previously claimed) > > As for this patch series, given that: > > > > commit (in -next) 903589ca7165 ("ARM: 8554/1: kernel: pci: remove > > pci=firmware command line parameter handling") removes the PCI_PROBE_ONLY > > handling from the (ARM) command line, the PCI host generic becomes the > > last ARM/ARM64 host controller that requires PCI_PROBE_ONLY to function > > (depending on DT settings). > > > > The idea behind adding pci_bus_claim_resources (patch 1) to core code > > was that it could be reused by other arches too, I do not have evidence > > though, I have to prove it, so I'd rather squash patch 1 into this one > > and make the code claiming resources local to the PCI host generic, > > I can't add a generic PCI core API just for one host controller > > (IMHO we should add an API that allows us to claim bus resources and > > realloc the ones for which claiming fail - which may mean releasing > > bridges resources and realloc/resize them - code is in the kernel already > > I have to write that API). > > > > The code claiming resources on x86, IA64 and PowerPC looks extremely > > similar but it has to be proven that a generic function has a chance > > to work, so patch 1 is not really justified at present. > > I don't really object to patch 1, but you're right that it's possible > we could do a better job later. I would certainly like to get that > sort of code (including the pcibios_allocate_resources() stuff I just > mentioned) out of the arches and into the core somehow. Problem with patch 1, is that, if resource claiming fails, it spits loads of noise in kernel logs (actually it is pci_claim_resource(), that patch 1 uses, that spits errors on claiming failure), that's a detail but it will make people unhappy. I do not think that if claiming for a particular resource fails we can consider it an error that's why I see patch 1 more PCI host generic PCI_PROBE_ONLY specific rather than anything else, we can't use it for !PCI_PROBE_ONLY systems unless I rework it to remove the kernel error logs on resource claiming failures. Probably on X86/IA64 resource claiming is spotless because on most if not all systems FW programmes the PCI bus and the kernel can take the set-up as-is, it is a question since I have no visibility into that. > > If you have no objections I will squash patch 1 into this one (moving > > the respective code in PCI host generic driver), and I would not merge > > this series till the commit above in -next gets in the kernel (which > > makes sure that PCI_PROBE_ONLY can't be set on the command line, that's > > fundamental to this series, at least on ARM, on ARM64 DT is the only way > > PCI_PROBE_ONLY can be set and only on host controllers that check the > > chosen node property - ie PCI host generic, that we are patching). > > If there's a stable branch containing 903589ca7165 ("ARM: 8554/1: > kernel: pci: remove pci=firmware command line parameter handling"), I > can pull that and merge your series on top of it. I think I should at least split patch 3 in two (one for ARM and one for ARM64), if Russell is forced to revert the commit above (because we discover pci=firmware command line users) I do not want ARM64 to be affected. Thanks ! Lorenzo ^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-04-18 10:01 ` Lorenzo Pieralisi @ 2016-04-18 14:49 ` Arnd Bergmann -1 siblings, 0 replies; 24+ messages in thread From: Arnd Bergmann @ 2016-04-18 14:49 UTC (permalink / raw) To: Lorenzo Pieralisi Cc: Bjorn Helgaas, linux-arm-kernel, linux-pci, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King On Monday 18 April 2016 11:01:54 Lorenzo Pieralisi wrote: > On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > > This last case 3) is the problem. I'm guessing this case doesn't > > currently occur on arm/arm64, but it's the normal case on x86, and it > > seems perverse that things work if firmware does nothing, but they > > don't work if firmware does more setup. > > IIUC X86 claim resources as programmed by FW so it is not really the > same situation as arm64, that claims nothing. Claimed resources are not > reassigned, they are skipped by resource allocation/sizing code > (because their parent pointer is set). > > And as I said above even if FW does some set-up that will still work > on ARM/ARM64, otherwise this means that on ALL ARM/ARM64 systems out there > PCI set-up at kernel handover is non-existent, otherwise we would > have resource enablement failures NOW, right ? The embedded systems (in which I would count all arm32 machines) tend to not do proper bus probing in their bootloaders, so we have to do it ourselves in the kernel. For server systems (all UEFI based ones), I'd argue that we should rely on the firmware to do it just like we do on x86, possibly with a blacklist of known-broken machines on which we have to do it manually as well. Once ACPI spreads, we will likely see an increasing number of machines on which we must not reassign the resources or bad things happen to stuff that is owned by the BIOS. Arnd ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-18 14:49 ` Arnd Bergmann 0 siblings, 0 replies; 24+ messages in thread From: Arnd Bergmann @ 2016-04-18 14:49 UTC (permalink / raw) To: linux-arm-kernel On Monday 18 April 2016 11:01:54 Lorenzo Pieralisi wrote: > On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > > This last case 3) is the problem. I'm guessing this case doesn't > > currently occur on arm/arm64, but it's the normal case on x86, and it > > seems perverse that things work if firmware does nothing, but they > > don't work if firmware does more setup. > > IIUC X86 claim resources as programmed by FW so it is not really the > same situation as arm64, that claims nothing. Claimed resources are not > reassigned, they are skipped by resource allocation/sizing code > (because their parent pointer is set). > > And as I said above even if FW does some set-up that will still work > on ARM/ARM64, otherwise this means that on ALL ARM/ARM64 systems out there > PCI set-up at kernel handover is non-existent, otherwise we would > have resource enablement failures NOW, right ? The embedded systems (in which I would count all arm32 machines) tend to not do proper bus probing in their bootloaders, so we have to do it ourselves in the kernel. For server systems (all UEFI based ones), I'd argue that we should rely on the firmware to do it just like we do on x86, possibly with a blacklist of known-broken machines on which we have to do it manually as well. Once ACPI spreads, we will likely see an increasing number of machines on which we must not reassign the resources or bad things happen to stuff that is owned by the BIOS. Arnd ^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-04-18 14:49 ` Arnd Bergmann @ 2016-04-18 17:31 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-18 17:31 UTC (permalink / raw) To: Arnd Bergmann Cc: Bjorn Helgaas, linux-arm-kernel, linux-pci, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King On Mon, Apr 18, 2016 at 04:49:43PM +0200, Arnd Bergmann wrote: > On Monday 18 April 2016 11:01:54 Lorenzo Pieralisi wrote: > > On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > > > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > > > > This last case 3) is the problem. I'm guessing this case doesn't > > > currently occur on arm/arm64, but it's the normal case on x86, and it > > > seems perverse that things work if firmware does nothing, but they > > > don't work if firmware does more setup. > > > > IIUC X86 claim resources as programmed by FW so it is not really the > > same situation as arm64, that claims nothing. Claimed resources are not > > reassigned, they are skipped by resource allocation/sizing code > > (because their parent pointer is set). > > > > And as I said above even if FW does some set-up that will still work > > on ARM/ARM64, otherwise this means that on ALL ARM/ARM64 systems out there > > PCI set-up at kernel handover is non-existent, otherwise we would > > have resource enablement failures NOW, right ? > > The embedded systems (in which I would count all arm32 machines) tend > to not do proper bus probing in their bootloaders, so we have to do it > ourselves in the kernel. > > For server systems (all UEFI based ones), I'd argue that we should > rely on the firmware to do it just like we do on x86, possibly with > a blacklist of known-broken machines on which we have to do it > manually as well. Once ACPI spreads, we will likely see an increasing > number of machines on which we must not reassign the resources or > bad things happen to stuff that is owned by the BIOS. The only way I can pull that off, is by writing an ARM64 PCI resource allocation function that does the following: - Try to claim the FW set-up - Realloc on claiming failures, inclusive of bridges resources releasing/resizing When to call it it has to be seen, either I do it on all ARM64 machines (but this requires significant testing because regressions are more than likely given that there are platforms on which we reassign everything already) or on !acpi_disabled (but I think that's wrong because I do not see why it is *only* dependent on ACPI), the sooner we implement it the better (and actually that's the reason why I wanted this function to be in the ACPI host controller code for ARM64 from the beginning - but if we do it at arch level it can be even more generic - again, when to call it it must be decided). Lorenzo ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-18 17:31 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-04-18 17:31 UTC (permalink / raw) To: linux-arm-kernel On Mon, Apr 18, 2016 at 04:49:43PM +0200, Arnd Bergmann wrote: > On Monday 18 April 2016 11:01:54 Lorenzo Pieralisi wrote: > > On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > > > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > > > > This last case 3) is the problem. I'm guessing this case doesn't > > > currently occur on arm/arm64, but it's the normal case on x86, and it > > > seems perverse that things work if firmware does nothing, but they > > > don't work if firmware does more setup. > > > > IIUC X86 claim resources as programmed by FW so it is not really the > > same situation as arm64, that claims nothing. Claimed resources are not > > reassigned, they are skipped by resource allocation/sizing code > > (because their parent pointer is set). > > > > And as I said above even if FW does some set-up that will still work > > on ARM/ARM64, otherwise this means that on ALL ARM/ARM64 systems out there > > PCI set-up at kernel handover is non-existent, otherwise we would > > have resource enablement failures NOW, right ? > > The embedded systems (in which I would count all arm32 machines) tend > to not do proper bus probing in their bootloaders, so we have to do it > ourselves in the kernel. > > For server systems (all UEFI based ones), I'd argue that we should > rely on the firmware to do it just like we do on x86, possibly with > a blacklist of known-broken machines on which we have to do it > manually as well. Once ACPI spreads, we will likely see an increasing > number of machines on which we must not reassign the resources or > bad things happen to stuff that is owned by the BIOS. The only way I can pull that off, is by writing an ARM64 PCI resource allocation function that does the following: - Try to claim the FW set-up - Realloc on claiming failures, inclusive of bridges resources releasing/resizing When to call it it has to be seen, either I do it on all ARM64 machines (but this requires significant testing because regressions are more than likely given that there are platforms on which we reassign everything already) or on !acpi_disabled (but I think that's wrong because I do not see why it is *only* dependent on ACPI), the sooner we implement it the better (and actually that's the reason why I wanted this function to be in the ACPI host controller code for ARM64 from the beginning - but if we do it at arch level it can be even more generic - again, when to call it it must be decided). Lorenzo ^ permalink raw reply [flat|nested] 24+ messages in thread
* Re: [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups 2016-04-18 10:01 ` Lorenzo Pieralisi @ 2016-04-19 21:03 ` Bjorn Helgaas -1 siblings, 0 replies; 24+ messages in thread From: Bjorn Helgaas @ 2016-04-19 21:03 UTC (permalink / raw) To: Lorenzo Pieralisi Cc: linux-arm-kernel, linux-pci, Arnd Bergmann, David Daney, Will Deacon, Bjorn Helgaas, Yinghai Lu, Catalin Marinas, Russell King On Mon, Apr 18, 2016 at 11:01:54AM +0100, Lorenzo Pieralisi wrote: > On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > > [...] > > > > > The next patch removes the arm and arm64 pcibios_enable_device() > > > > implementations, which implies that arm and arm64 only need the generic > > > > version, which simply calls pci_enable_resources(). That assumes r->parent > > > > is set. > > > > > > > > After this patch, we'll call pci_bus_claim_resources() for the > > > > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > > > > > > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > > > > that path *works*, because you're not changing anything there. I'd just > > > > like to have a hint that makes this change more obvious. > > > > > > On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the > > > kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need > > > this patch), resources are always reassigned and the core code reassigning > > > them takes care of assigning their parent pointers too, to answer your > > > question. > > > > Here's what I find confusing. Consider these three cases: > > > > 1) Firmware programs no BARs and we reassign everything. We call > > pci_bus_assign_resources(), and the pci_assign_resource() ... > > allocate_resource() path makes sure everything is claimed. This is > > apparently the normal arm/arm64 path, and it already works. > > > > 2) Firmware programs all BARs and we set PCI_PROBE_ONLY. After this > > series, we'll claim the resources and remove the PCI_PROBE_ONLY > > special case in pcibios_enable_device(). This is great! > > > > 3) Firmware programs all BARs but we don't set PCI_PROBE_ONLY. We > > call pci_bus_assign_resources(), but I think it does nothing because > > everything is already assigned. The resources are not claimed and > > pci_enable_resources() will fail. > > I do not expect (1) and (3) to be different from a kernel resource > allocation perspective. > > If the core resource layer is asked to assign resources it will, > regardless of what FW programmed in the BARs (the BAR regions size > matters, that's it), I went through pci_bus_assign_resources() a couple > of times and I have to add a bit of debugging so give me the benefit of > the doubt please, but there is nothing that let me think it won't assign > resources (and therefore assign a parent pointer) if the resources are > already programmed correctly (actually I even think the kernel may > change what FW programmed according to its resource alloc policy). OK. If you're saying that even if FW programmed the BARs, the core will assign resources and set r->parent, that's all I'm looking for. I *would* like a comment where we test PCI_PROBE_ONLY to the effect that for PCI_PROBE_ONLY we call pci_bus_claim_resources(), and for !PCI_PROBE_ONLY, we claim the resources in pci_bus_assign_resources(). Bjorn ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups @ 2016-04-19 21:03 ` Bjorn Helgaas 0 siblings, 0 replies; 24+ messages in thread From: Bjorn Helgaas @ 2016-04-19 21:03 UTC (permalink / raw) To: linux-arm-kernel On Mon, Apr 18, 2016 at 11:01:54AM +0100, Lorenzo Pieralisi wrote: > On Fri, Apr 15, 2016 at 08:08:03AM -0500, Bjorn Helgaas wrote: > > On Tue, Apr 12, 2016 at 04:48:10PM +0100, Lorenzo Pieralisi wrote: > > [...] > > > > > The next patch removes the arm and arm64 pcibios_enable_device() > > > > implementations, which implies that arm and arm64 only need the generic > > > > version, which simply calls pci_enable_resources(). That assumes r->parent > > > > is set. > > > > > > > > After this patch, we'll call pci_bus_claim_resources() for the > > > > PCI_PROBE_ONLY case, and that sets r->parent for all the resources. > > > > > > > > Where does r->parent get set in the non-PCI_PROBE_ONLY case? Obviously > > > > that path *works*, because you're not changing anything there. I'd just > > > > like to have a hint that makes this change more obvious. > > > > > > On all ARM/ARM64 PCI controllers drivers I am aware of (apart from the > > > kvmtool PCI host controller which does require PCI_PROBE_ONLY, so we need > > > this patch), resources are always reassigned and the core code reassigning > > > them takes care of assigning their parent pointers too, to answer your > > > question. > > > > Here's what I find confusing. Consider these three cases: > > > > 1) Firmware programs no BARs and we reassign everything. We call > > pci_bus_assign_resources(), and the pci_assign_resource() ... > > allocate_resource() path makes sure everything is claimed. This is > > apparently the normal arm/arm64 path, and it already works. > > > > 2) Firmware programs all BARs and we set PCI_PROBE_ONLY. After this > > series, we'll claim the resources and remove the PCI_PROBE_ONLY > > special case in pcibios_enable_device(). This is great! > > > > 3) Firmware programs all BARs but we don't set PCI_PROBE_ONLY. We > > call pci_bus_assign_resources(), but I think it does nothing because > > everything is already assigned. The resources are not claimed and > > pci_enable_resources() will fail. > > I do not expect (1) and (3) to be different from a kernel resource > allocation perspective. > > If the core resource layer is asked to assign resources it will, > regardless of what FW programmed in the BARs (the BAR regions size > matters, that's it), I went through pci_bus_assign_resources() a couple > of times and I have to add a bit of debugging so give me the benefit of > the doubt please, but there is nothing that let me think it won't assign > resources (and therefore assign a parent pointer) if the resources are > already programmed correctly (actually I even think the kernel may > change what FW programmed according to its resource alloc policy). OK. If you're saying that even if FW programmed the BARs, the core will assign resources and set r->parent, that's all I'm looking for. I *would* like a comment where we test PCI_PROBE_ONLY to the effect that for PCI_PROBE_ONLY we call pci_bus_claim_resources(), and for !PCI_PROBE_ONLY, we claim the resources in pci_bus_assign_resources(). Bjorn ^ permalink raw reply [flat|nested] 24+ messages in thread
* [PATCH v2 3/3] arm/arm64: pci: remove arch specific pcibios_enable_device() 2016-03-01 14:44 ` Lorenzo Pieralisi @ 2016-03-01 14:44 ` Lorenzo Pieralisi -1 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel, linux-pci Cc: Lorenzo Pieralisi, Arnd Bergmann, Will Deacon, Bjorn Helgaas, Catalin Marinas, Russell King, David Daney, Yinghai Lu The arm/arm64 pcibios_enable_device() implementations exist solely to prevent enabling PCI resources on PROBE_ONLY systems, since on those systems the PCI resources are currently not claimed (ie validated and inserted in the PCI resource tree) therefore they can not be enabled since this would trigger PCI set-ups failures. By introducing resources claiming in the PCI host controllers set-ups that have PROBE_ONLY as a probe option, there is no need for arch specific pcibios_enable_device() implementations anymore in that the kernel can rely on the generic pcibios_enable_device() implementation without resorting to arch specific code to work around the missing resources claiming enumeration step. This patch removes the pcibios_enable_device() implementations from the arm/arm64 arches back-end. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> --- arch/arm/kernel/bios32.c | 12 ------------ arch/arm64/kernel/pci.c | 13 ------------- 2 files changed, 25 deletions(-) diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index 05e61a2..488545f 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -590,18 +590,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, return start; } -/** - * pcibios_enable_device - Enable I/O and memory. - * @dev: PCI device to be enabled - */ -int pcibios_enable_device(struct pci_dev *dev, int mask) -{ - if (pci_has_flag(PCI_PROBE_ONLY)) - return 0; - - return pci_enable_resources(dev, mask); -} - int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine) { diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index b3d098b..4095379 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -38,19 +38,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, return res->start; } -/** - * pcibios_enable_device - Enable I/O and memory. - * @dev: PCI device to be enabled - * @mask: bitmask of BARs to enable - */ -int pcibios_enable_device(struct pci_dev *dev, int mask) -{ - if (pci_has_flag(PCI_PROBE_ONLY)) - return 0; - - return pci_enable_resources(dev, mask); -} - /* * Try to assign the IRQ number from DT when adding a new device */ -- 2.5.1 ^ permalink raw reply related [flat|nested] 24+ messages in thread
* [PATCH v2 3/3] arm/arm64: pci: remove arch specific pcibios_enable_device() @ 2016-03-01 14:44 ` Lorenzo Pieralisi 0 siblings, 0 replies; 24+ messages in thread From: Lorenzo Pieralisi @ 2016-03-01 14:44 UTC (permalink / raw) To: linux-arm-kernel The arm/arm64 pcibios_enable_device() implementations exist solely to prevent enabling PCI resources on PROBE_ONLY systems, since on those systems the PCI resources are currently not claimed (ie validated and inserted in the PCI resource tree) therefore they can not be enabled since this would trigger PCI set-ups failures. By introducing resources claiming in the PCI host controllers set-ups that have PROBE_ONLY as a probe option, there is no need for arch specific pcibios_enable_device() implementations anymore in that the kernel can rely on the generic pcibios_enable_device() implementation without resorting to arch specific code to work around the missing resources claiming enumeration step. This patch removes the pcibios_enable_device() implementations from the arm/arm64 arches back-end. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Will Deacon <will.deacon@arm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <linux@arm.linux.org.uk> --- arch/arm/kernel/bios32.c | 12 ------------ arch/arm64/kernel/pci.c | 13 ------------- 2 files changed, 25 deletions(-) diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index 05e61a2..488545f 100644 --- a/arch/arm/kernel/bios32.c +++ b/arch/arm/kernel/bios32.c @@ -590,18 +590,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, return start; } -/** - * pcibios_enable_device - Enable I/O and memory. - * @dev: PCI device to be enabled - */ -int pcibios_enable_device(struct pci_dev *dev, int mask) -{ - if (pci_has_flag(PCI_PROBE_ONLY)) - return 0; - - return pci_enable_resources(dev, mask); -} - int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, enum pci_mmap_state mmap_state, int write_combine) { diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index b3d098b..4095379 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -38,19 +38,6 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, return res->start; } -/** - * pcibios_enable_device - Enable I/O and memory. - * @dev: PCI device to be enabled - * @mask: bitmask of BARs to enable - */ -int pcibios_enable_device(struct pci_dev *dev, int mask) -{ - if (pci_has_flag(PCI_PROBE_ONLY)) - return 0; - - return pci_enable_resources(dev, mask); -} - /* * Try to assign the IRQ number from DT when adding a new device */ -- 2.5.1 ^ permalink raw reply related [flat|nested] 24+ messages in thread
end of thread, other threads:[~2016-04-26 12:47 UTC | newest] Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2016-03-01 14:44 [PATCH v2 0/3] arm/arm64: pci: PCI_PROBE_ONLY clean-up Lorenzo Pieralisi 2016-03-01 14:44 ` Lorenzo Pieralisi 2016-03-01 14:44 ` [PATCH v2 1/3] drivers: pci: add generic code to claim bus resources Lorenzo Pieralisi 2016-03-01 14:44 ` Lorenzo Pieralisi 2016-04-26 12:47 ` Lorenzo Pieralisi 2016-04-26 12:47 ` Lorenzo Pieralisi 2016-03-01 14:44 ` [PATCH v2 2/3] drivers: pci: host-generic: claim bus resources on PCI_PROBE_ONLY set-ups Lorenzo Pieralisi 2016-03-01 14:44 ` Lorenzo Pieralisi 2016-04-12 4:43 ` Bjorn Helgaas 2016-04-12 4:43 ` Bjorn Helgaas 2016-04-12 15:48 ` Lorenzo Pieralisi 2016-04-12 15:48 ` Lorenzo Pieralisi 2016-04-15 13:08 ` Bjorn Helgaas 2016-04-15 13:08 ` Bjorn Helgaas 2016-04-18 10:01 ` Lorenzo Pieralisi 2016-04-18 10:01 ` Lorenzo Pieralisi 2016-04-18 14:49 ` Arnd Bergmann 2016-04-18 14:49 ` Arnd Bergmann 2016-04-18 17:31 ` Lorenzo Pieralisi 2016-04-18 17:31 ` Lorenzo Pieralisi 2016-04-19 21:03 ` Bjorn Helgaas 2016-04-19 21:03 ` Bjorn Helgaas 2016-03-01 14:44 ` [PATCH v2 3/3] arm/arm64: pci: remove arch specific pcibios_enable_device() Lorenzo Pieralisi 2016-03-01 14:44 ` Lorenzo Pieralisi
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