From mboxrd@z Thu Jan 1 00:00:00 1970 From: suravee.suthikulpanit@amd.com (Suravee Suthikulanit) Date: Thu, 14 May 2015 21:09:03 -0500 Subject: [RFC/RFT PATCH 2/2] ARM64: kernel: pci: implement PCI device resources claiming In-Reply-To: <1431614537-16136-2-git-send-email-lorenzo.pieralisi@arm.com> References: <1431614537-16136-1-git-send-email-lorenzo.pieralisi@arm.com> <1431614537-16136-2-git-send-email-lorenzo.pieralisi@arm.com> Message-ID: <5555553F.9070608@amd.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 5/14/2015 9:42 AM, Lorenzo Pieralisi wrote: > When a device is scanned and added to the PCI bus, its resources > should be claimed to validate the BARs configuration and to assign > them a parent resource so that the resource hierarchy can be sanity > checked. > > This patch adds code that carries out PCI device resources claiming to > the ARM64 pcibios_add_device implementation so that device resources > are claimed by the core PCI layer upon PCI device initialization on > ARM64 systems. > > Signed-off-by: Lorenzo Pieralisi > Cc: Arnd Bergmann > Cc: Will Deacon > Cc: Liviu Dudau > Cc: Bjorn Helgaas > --- > arch/arm64/kernel/pci.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c > index 4095379..c0a88ca 100644 > --- a/arch/arm64/kernel/pci.c > +++ b/arch/arm64/kernel/pci.c > @@ -43,8 +43,18 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res, > */ > int pcibios_add_device(struct pci_dev *dev) > { > + struct resource *res; > + int i; > + > dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); > > + for (i = 0; i < PCI_NUM_RESOURCES; i++) { > + res = &dev->resource[i]; > + if (res->parent || !res->flags) > + continue; > + pci_claim_resource(dev, i); > + } > + > return 0; > } > > Lorenzo/Bjorn, I have tested this patch on top of Jayachandran's V2 patch series (http://www.spinics.net/lists/linux-pci/msg40811.html) on AMD Seattle (w/ PROBE_ONLY and non-PROBE_ONLY mode), and your changes here works with additional changes below. It seems that when booting w/ PROBE_ONLY case, we need to call pci_read_bridge_bases() at some point before claiming the resources of devices underneath the bridge. This is needed to determine the bridge bases (i.e. bridge io, mmio and mmio_pref bases), and update bridge resources accordingly. ---- BEGIN PATCH ----- diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c index c0a88ca..57be6aa 100644 --- a/arch/arm64/kernel/pci.c +++ b/arch/arm64/kernel/pci.c @@ -48,6 +48,11 @@ int pcibios_add_device(struct pci_dev *dev) dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); + if (pci_has_flag(PCI_PROBE_ONLY) && + !pci_is_root_bus(dev->bus) && + !pci_bridge_bases_is_read(dev->bus)) + pci_read_bridge_bases(dev->bus); + for (i = 0; i < PCI_NUM_RESOURCES; i++) { res = &dev->resource[i]; if (res->parent || !res->flags) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 6675a7a..6cab8be 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -447,6 +447,13 @@ static void pci_read_bridge_mmio_pref(struct pci_bus *child) } } +bool pci_bridge_bases_is_read(struct pci_bus *bus) +{ + return (bus->resource[0]->start || + bus->resource[1]->start || + bus->resource[2]->start); +} + void pci_read_bridge_bases(struct pci_bus *child) { struct pci_dev *dev = child->self; diff --git a/include/linux/pci.h b/include/linux/pci.h index 353db8d..11c674d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -798,6 +798,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus); unsigned int pci_scan_child_bus(struct pci_bus *bus); void pci_bus_add_device(struct pci_dev *dev); void pci_read_bridge_bases(struct pci_bus *child); +bool pci_bridge_bases_is_read(struct pci_bus *bus); struct resource *pci_find_parent_resource(const struct pci_dev *dev, struct resource *res); u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin); ---- END PATCH ----- I'm not sure if this is the best place to be reading the bridge bases. I guess we should be able to do this when adding bridge devices. Thanks, Suravee