From 18126f35f69c928af26ec1dda2cb91b23220cdd4 Mon Sep 17 00:00:00 2001 From: Linas Vepstas Date: Thu, 3 Nov 2005 18:49:38 -0600 Subject: [PATCH] [PATCH] ppc64: bugfix: crash on PCI hotplug 09-hotplug-bugfix.patch In the current 2.6.14-rc2-git6 kernel, performing a Dynamic LPAR Add of a hotplug slot will crash the system, with the following (abbreviated) stack trace: cpu 0x3: Vector: 700 (Program Check) at [c000000053dff7f0] pc: c0000000004f5974: .__alloc_bootmem+0x0/0xb0 lr: c0000000000258a0: .update_dn_pci_info+0x108/0x118 c0000000000257c8 .update_dn_pci_info+0x30/0x118 (unreliable) c0000000000258fc .pci_dn_reconfig_notifier+0x4c/0x64 c000000000060754 .notifier_call_chain+0x68/0x9c The root cause was that __init __alloc_bootmem() was called long after boot had finished, resulting in a crash because this routine is undefined after boot time. The patch below fixes this crash, and adds some docs to clarify the code. Signed-off-by: Linas Vepstas Signed-off-by: Paul Mackerras --- arch/ppc64/kernel/pci_dn.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/arch/ppc64/kernel/pci_dn.c b/arch/ppc64/kernel/pci_dn.c index 1a443a7ada..12c4c9e9bb 100644 --- a/arch/ppc64/kernel/pci_dn.c +++ b/arch/ppc64/kernel/pci_dn.c @@ -43,7 +43,7 @@ static void * __devinit update_dn_pci_info(struct device_node *dn, void *data) u32 *regs; struct pci_dn *pdn; - if (phb->is_dynamic) + if (mem_init_done) pdn = kmalloc(sizeof(*pdn), GFP_KERNEL); else pdn = alloc_bootmem(sizeof(*pdn)); @@ -120,6 +120,14 @@ void *traverse_pci_devices(struct device_node *start, traverse_func pre, return NULL; } +/** + * pci_devs_phb_init_dynamic - setup pci devices under this PHB + * phb: pci-to-host bridge (top-level bridge connecting to cpu) + * + * This routine is called both during boot, (before the memory + * subsystem is set up, before kmalloc is valid) and during the + * dynamic lpar operation of adding a PHB to a running system. + */ void __devinit pci_devs_phb_init_dynamic(struct pci_controller *phb) { struct device_node * dn = (struct device_node *) phb->arch_data; @@ -201,9 +209,14 @@ static struct notifier_block pci_dn_reconfig_nb = { .notifier_call = pci_dn_reconfig_notifier, }; -/* - * Actually initialize the phbs. - * The buswalk on this phb has not happened yet. +/** + * pci_devs_phb_init - Initialize phbs and pci devs under them. + * + * This routine walks over all phb's (pci-host bridges) on the + * system, and sets up assorted pci-related structures + * (including pci info in the device node structs) for each + * pci device found underneath. This routine runs once, + * early in the boot sequence. */ void __init pci_devs_phb_init(void) { -- 2.39.5