On Tue, Apr 19, 2016 at 06:19:20PM +1000, Alexey Kardashevskiy wrote: >On 02/17/2016 02:44 PM, Gavin Shan wrote: >>The pdn (struct pci_dn) instances are allocated from memblock or >>bootmem when creating PCI controller (hoses) in setup_arch(). PCI >>hotplug, which will be supported by proceeding patches, releases >>PCI device nodes and their corresponding pdn on unplugging event. >>The memory chunks for pdn instances allocated from memblock or >>bootmem are hard to reused after being released. >> >>This delays creating pdn by pci_devs_phb_init() from setup_arch() >>to core_initcall() so that they are allocated from slab. The memory >>consumed by pdn can be released to system without problem during >>PCI unplugging time. It indicates that pci_dn is unavailable in >>setup_arch() and the the fixup on pdn (like AGP's) can't be carried >>out that time. We have to do that in ppc_md.pcibios_root_bridge_prepare() >>on maple/pasemi/powermac platforms where/when the pdn is available. >> >>At the mean while, the EEH device is created when pdn is populated, >>meaning pdn and EEH device have same life cycle. In turn, we needn't >>call eeh_dev_init() to create EEH device explicitly. >> >>Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> > > >Uff. It would not hurt to mention that pcibios_root_bridge_prepare is called >from subsys_initcall() which is executed after core_initcall() so the code >flow does not change. > Yes, will do in next revision. >Have you checked if there is anything in between >core_initcall(pci_devs_phb_init) and subsys_initcall(pcibios_init) which >might need device tree nodes? For example, subsys_initcall(pcibios_init) >calls (eventually) pnv_pci_ioda_fixup(), if we are unlucky and pcibios_init() >(and therefore pnv_pci_ioda_fixup() or what pseries/others do) is called >before pcibios_init() - won't we crash or something? > I don't catch what you were asking. device-tree nodes (struct device_node) are always there. This patch doesn't affect them. Perhaps you were talking about pdn (PCI_DN). If it's the case, this patch delays creating pdn from setup_arch() to core_initcall(pci_devs_phb_init). I don't see anything need pdn between setup_arch() and core_initcall(). The changes introduced to powermac/pasemi platforms are: move fixing the child pdns of the specifiec PHB's pdn from setup_arch() to subsys_initcall(pcibios_init). I don't see anything between them needs the fixed pdns. I don't understand how pcibios_init() is called before pcibios_init() in your context. Sorry for my bad English. Perhaps you're asking the the called sequence on core_initcall() and subsys_init()? If so, they're defined like below: #define core_initcall(fn) __define_initcall(fn, 1) #define subsys_initcall(fn) __define_initcall(fn, 4) > >-- >Alexey > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
