On Fri, Feb 22, 2019 at 2:24 PM Sam Bobroff <sbobr...@linux.ibm.com> wrote: > > Hey all, > > After some consideration, I've decided to post a v2 of this patch that > will make it a bit safer (although I haven't seen any problems with it) > and make it a little easier to refactor some of the EEH code that > interacts with the hooks.
Can you be a little more specific? > Cheers, > Sam. > > On Thu, Feb 14, 2019 at 04:14:42PM +1100, Sam Bobroff wrote: > > The pcibios_init() function for 64 bit PowerPC currently calls > > pci_bus_add_devices() before pcibios_resource_survey(), which seems > > incorrect because it adds devices and attempts to bind their drivers > > before allocating their resources (although no problems seem to be > > apparent). > > > > So move the call to pci_bus_add_devices() to after > > pcibios_resource_survey(). > > > > This will also allow the ppc_md.pcibios_bus_add_device() hooks to > > perform actions that depend on PCI resources, both during rescanning > > (where this is already the case) and at boot time, which should > > support improvements and refactoring. > > > > Signed-off-by: Sam Bobroff <sbobr...@linux.ibm.com> > > --- > > Hi everyone, > > > > I've tested this on a P9 for both the host and a KVM guest, and the change > > hasn't caused any differences in PCI resource assignments or the general > > boot > > messages. > > > > I've also had a go at inspecting most of the code used by > > pci_bus_add_devices() > > and pcibios_resource_survey() and it doesn't look like there are going to be > > any changes in behaviour caused by reordering. It might be worth mentioning > > that the hotplug path (see pcibios_finish_adding_to_bus()) already does > > resource allocation before calling pci_bus_add_devices(). > > > > However, it would be great if someone could test this change on some older > > hardware or comment on wether we should make the same change on 32 bit > > machines. > > > > Cheers, > > Sam. > > > > arch/powerpc/kernel/pci_64.c | 8 +++++--- > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c > > index 9d8c10d55407..1ce28888dbdb 100644 > > --- a/arch/powerpc/kernel/pci_64.c > > +++ b/arch/powerpc/kernel/pci_64.c > > @@ -58,14 +58,16 @@ static int __init pcibios_init(void) > > pci_add_flags(PCI_ENABLE_PROC_DOMAINS | PCI_COMPAT_DOMAIN_0); > > > > /* Scan all of the recorded PCI controllers. */ > > - list_for_each_entry_safe(hose, tmp, &hose_list, list_node) { > > + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) > > pcibios_scan_phb(hose); > > - pci_bus_add_devices(hose->bus); > > - } > > > > /* Call common code to handle resource allocation */ > > pcibios_resource_survey(); > > > > + /* Add devices. */ > > + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) > > + pci_bus_add_devices(hose->bus); > > + > > printk(KERN_DEBUG "PCI: Probing PCI hardware done\n"); > > > > return 0; > > -- > > 2.19.0.2.gcad72f5712 > >