On 26/07/15 19:43, Jayachandran C. wrote: > On Sun, Jul 26, 2015 at 07:16:46PM +0100, Lorenzo Pieralisi wrote: >> On Sun, Jul 26, 2015 at 04:25:29PM +0100, Jayachandran C. wrote: >>> On Fri, Jul 24, 2015 at 05:13:03PM +0100, Lorenzo Pieralisi wrote: >>>> On ARM PCI systems relying on the pcibios API to initialize PCI host >>>> controllers, the pcibios_msi_controller weak callback is used to look-up >>>> the msi_controller pointer, through pci_sys_data msi_ctrl pointer. >>>> >>>> pci_sys_data is an ARM specific structure, which prevents using the >>>> same mechanism (so same PCI host controller drivers) on ARM64 systems. >>>> >>>> Since the struct pci_bus already contains an msi_controller pointer and >>>> the kernel already uses it to look-up the msi controller, >>>> this patch converts ARM host controller and related pcibios/host bridges >>>> initialization routines so that the msi_controller pointer look-up can be >>>> carried out by PCI core code through the struct pci_bus msi pointer, >>>> removing the need for the arch specific pcibios_msi_controller callback >>>> and the related pci_sys_data msi_ctrl pointer. >>>> >>>> ARM is the only arch relying on the pcibios_msi_controller() weak >>>> function, hence this patch removes the default weak implementation >>>> from PCI core code since it becomes of no use. >>>> >>>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx> >>>> Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> >>>> Cc: Pratyush Anand <pratyush.anand@xxxxxxxxx> >>>> Cc: Arnd Bergmann <arnd@xxxxxxxx> >>>> Cc: Jingoo Han <jingoohan1@xxxxxxxxx> >>>> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >>>> Cc: Simon Horman <horms@xxxxxxxxxxxx> >>>> Cc: Russell King <linux@xxxxxxxxxxxxxxxx> >>>> Cc: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> >>>> Cc: Thierry Reding <thierry.reding@xxxxxxxxx> >>>> Cc: Michal Simek <michal.simek@xxxxxxxxxx> >>>> Cc: Marc Zyngier <marc.zyngier@xxxxxxx> >>>> --- >>>> v1->v2 >>>> >>>> - Added patch to replace panic statements with WARN >>>> - Removed unused pcibios_msi_controller() and pci_msi_controller() from >>>> core code >>>> - Dropped RFT status >>>> >>>> v1: http://lists.infradead.org/pipermail/linux-arm-kernel/2015-July/356028.html >>>> >>>> arch/arm/include/asm/mach/pci.h | 3 --- >>>> arch/arm/kernel/bios32.c | 29 +++++++++++++---------------- >>>> drivers/pci/host/pcie-designware.c | 9 +++++++-- >>>> drivers/pci/host/pcie-xilinx.c | 12 ++++++++++-- >>>> drivers/pci/msi.c | 17 +---------------- >>>> 5 files changed, 31 insertions(+), 39 deletions(-) >>>> >>> [...] >>>> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >>>> index f66be86..0d20142 100644 >>>> --- a/drivers/pci/msi.c >>>> +++ b/drivers/pci/msi.c >>>> @@ -77,24 +77,9 @@ static void pci_msi_teardown_msi_irqs(struct pci_dev *dev) >>>> >>>> /* Arch hooks */ >>>> >>>> -struct msi_controller * __weak pcibios_msi_controller(struct pci_dev *dev) >>>> -{ >>>> - return NULL; >>>> -} >>>> - >>>> -static struct msi_controller *pci_msi_controller(struct pci_dev *dev) >>>> -{ >>>> - struct msi_controller *msi_ctrl = dev->bus->msi; >>>> - >>>> - if (msi_ctrl) >>>> - return msi_ctrl; >>>> - >>>> - return pcibios_msi_controller(dev); >>>> -} >>>> - >>>> int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc) >>>> { >>>> - struct msi_controller *chip = pci_msi_controller(dev); >>>> + struct msi_controller *chip = dev->bus->msi; >>>> int err; >>>> >>>> if (!chip || !chip->setup_irq) >>> >>> Don't you have to go to the top level bus and get the ->msi pointer? Something >>> like: >>> >>> for (bus = dev->bus; bus != NULL; bus = bus->parent) >>> if (bus->msi) >>> return bus->msi; >>> >>> I have not been following this closely, so I may have missed some patches. >> >> The msi pointer is initialized from parent to child in >> pci_alloc_child_bus(), so PCI core does that for us, >> that's my understanding. >> >> It works the same as sysdata pointer, which is why >> pcibios_msi_controller works in the current kernel. > > Thanks. > >> On a side note, are you able to prepare a new version >> of your set to enable the PCI generic host on ARM64 >> (and remove pci_sys_data and related ifdef CONFIG_ARM >> from it) ? >> >> We are not far from removing the pci_sys_data dependency, >> if you can't prepare a new version of your series let me >> know I can do it on your behalf. > > I will post an updated patch with a minor fix. I will also > add a patch for parsing msi-parent and setting ->msi on > the root bus. That shouldn't be necessary if you base your series on this one: http://lwn.net/Articles/652151/ Patch 5 in this series does it for you as part of the core PCI code. Thanks, M. -- Jazz is not dead. It just smells funny... -- 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
