[+ Yinghai] On Mon, Feb 29, 2016 at 02:03:45PM -0500, Sinan Kaya wrote: > On 2/16/2016 8:53 AM, Tomasz Nowicki wrote: > > From the functionality point of view this series might be split into the > > following logic parts: > > 1. Make MMCONFIG code arch-agnostic which allows all architectures to collect > > PCI config regions and used when necessary. > > 2. Move non-arch specific bits to the core code. > > 3. Use MMCONFIG code and implement generic ACPI based PCI host controller driver. > > 4. Enable above driver on ARM64 > > > > Patches has been built on top of 4.5-rc3 and can be found here: > > git@xxxxxxxxxx:semihalf-nowicki-tomasz/linux.git (pci-acpi-v5) > > > > NOTE, this patch set depends on Lorenzo's fixes: > > https://patchwork.ozlabs.org/patch/576450/ > > which can be found in pci-acpi-v5 branch. > > > > This has been tested on Cavium ThunderX server, JunoR2, HP RX2660 IA64, x86, > > Hip05, X-Gene and QEMU-aarch64. Any help in reviewing and testing is very appreciated. > > > > v4 -> v5 > > - dropped MCFG refactoring group patches 1-6 from series v4 and integrated Jayachandran's patch > > https://patchwork.ozlabs.org/patch/575525/ > > - rewrite PCI legacy IRQs allocation > > - squashed two patches 11 and 12 from series v4, fixed bisection issue > > - changelog improvements > > - rebased to 4.5-rc3 > > > > v3 -> v4 > > - dropped Jiang's fix http://lkml.iu.edu/hypermail/linux/kernel/1601.1/04318.html > > - added Lorenzo's fix patch 19/24 > > - ACPI PCI bus domain number assigning cleanup > > - changed resource management, we now claim and reassign resources > > - improvements for applying quirks > > - dropped Matthew's http://www.spinics.net/lists/linux-pci/msg45950.html dependency > > - rebased to 4.5-rc1 > > > > Having tested v4 and v5, I'm seeing some resource assignment problems > and address conflicts. And problems booting QEMU. I asked Tomasz to add resource claiming code in v4 to make sure that, if FW has left resources in a reasonable set-up, we reuse it as-is. Now, I was and I am aware this could trigger resource allocation issues (in particular in relation to bridges apertures sizing), that can be nonetheless solved by forcing the kernel to reallocate resources (pci=realloc, that's exactly what's there for, release the bridge apertures, resize the busses downstream and reassign the respective hierarchy). I am not entirely aware of how consistently pci=realloc was used on x86, what I am aware of is the panoply of pci=* command line parameters defined for x86 and I would certainly avoid that. The decision on whether we claim resources before reassigning them is either dictacted by the boot method (ie ACPI->claim resources by default) or we should control it via a FW option or a command line option, PCI standard (PCI FW revision 3.1, 3.5 "Device State at Firmware/Operating System Handoff) IIUC does not stricly mandate FW configuring the whole PCI hierarchy (and to be 100% compliant we should check the device IO/MEM enable bits before claiming, as x86 does - see pcibios_allocate_dev_resources() in arch/x86/pci/i386.c). x86 and IA64 claim PCI resources on boot and live with that (well, minus the gazillions x86 pci= parameters that change the PCI resources assignment one way or another), comments very welcome in particular on the pci=realloc option and its usage. What's certain is, if we do not claim resources by default we will *never* be able to do it, it will certainly trigger regressions. Lorenzo -- 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
