Hi Arnd, Please see my comments inline. > -----Original Message----- > From: Arnd Bergmann [mailto:arnd@xxxxxxxx] > Sent: Wednesday, April 15, 2015 6:17 PM > To: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: Lian Minghuan-B31939; linux-pci@xxxxxxxxxxxxxxx; Jingoo Han; Hu > Mingkai-B21284; Zang Roy-R61911; Yoder Stuart-B08248; Bjorn Helgaas; > Wood Scott-B07421 > Subject: Re: [PATCH v2 1/3] arm/pci: Add support architecture-independent > PCIe driver > > On Wednesday 15 April 2015 17:48:33 Minghuan Lian wrote: > > PCIe common driver of arm architecture uses private structure > > pci_sys_data and hw_pci to associate with specific PCIe controller ops > > which results in the PCIe controller driver not compatible with other > > architectures. This patch provides another approach to support > > architecture-independent PCIe driver which does not need to use > > pci_sys_data and hw_pci and call pci_common_init_dev(). > > > > Signed-off-by: Minghuan Lian <Minghuan.Lian@xxxxxxxxxxxxx> > > This looks ok in principle, but I think we already have plans to fix this up in a > better way. > > Your code is broken in the theoretical case where you'd have two PCI host > bridges, and only one of them uses pci_common_init_dev. > [Minghuan] Yes, my method is not really good, it is just a workaround before the better fixup is merged. > > diff --git a/arch/arm/kernel/bios32.c b/arch/arm/kernel/bios32.c index > > ab19b7c0..8820ed5 100644 > > --- a/arch/arm/kernel/bios32.c > > +++ b/arch/arm/kernel/bios32.c > > @@ -7,6 +7,7 @@ > > */ > > #include <linux/export.h> > > #include <linux/kernel.h> > > +#include <linux/of_pci.h> > > #include <linux/pci.h> > > #include <linux/slab.h> > > #include <linux/init.h> > > @@ -17,12 +18,16 @@ > > #include <asm/mach/pci.h> > > > > static int debug_pci; > > +static int pci_commont_init_enable; > > > > #ifdef CONFIG_PCI_MSI > > struct msi_controller *pcibios_msi_controller(struct pci_dev *dev) { > > struct pci_sys_data *sysdata = dev->bus->sysdata; > > > > + if (!pci_commont_init_enable) > > + return NULL; > > + > > return sysdata->msi_ctrl; > > } > > #endif > > @@ -508,6 +513,8 @@ void pci_common_init_dev(struct device *parent, > struct hw_pci *hw) > > struct pci_sys_data *sys; > > LIST_HEAD(head); > > > > + pci_commont_init_enable = 1; > > + > > pci_add_flags(PCI_REASSIGN_ALL_RSRC); > > if (hw->preinit) > > hw->preinit(); > > A simpler hack to achieve the same thing is to add an empty pci_sys_data > member to the designware pcie_port: > > +++ b/drivers/pci/host/pcie-designware.h > @@ -23,6 +23,15 @@ > #define MAX_MSI_CTRLS (MAX_MSI_IRQS / 32) > > struct pcie_port { > +#ifdef CONFIG_ARM > + /* > + * this is a temporary hack to let the driver work on > + * both arm32 and arm64. it can be removed after the > + * arm32 cleanup is complete and bios32.c has stopped > + * referencing host->pci_sys_data. > + */ > + struct pci_sys_data dummy; > +#endif > struct device *dev; > u8 root_bus_nr; > void __iomem *dbi_base; > > I've just drafted a patch in reply to the hisilicon patch that tries to achieve the > same thing as yours, see "Re: [RFC PATCH 1/3] PCI: host: > designware: support ARM64". > > > > @@ -651,3 +658,13 @@ void __init pci_map_io_early(unsigned long pfn) > > pci_io_desc.pfn = pfn; > > iotable_init(&pci_io_desc, 1); > > } > > + > > +/* > > + * Try to assign the IRQ number from DT when adding a new device */ > > +int pcibios_add_device(struct pci_dev *dev) { > > + dev->irq = of_irq_parse_and_map_pci(dev, 0, 0); > > + > > + return 0; > > +} > > I don't see why this is required here. Doesn't this break platforms that get > their IRQ in some other way? > [Minghuan] It is for IRQ map to replace sys->map_irq. > Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
