[PATCH 9/22] ppc64: DLPAR slot add and remove bugfixes

linas
2005-10-06T23:35:07Z

09-crash-on-pci-slot-remove.patch

This patch fixes two bugs related to dlpar slot removal and add.

-- Both crashes are due to the fact the some children
of pci nodes are not pci nodes themselves, and thus do not
have pci_dn structures. For example:
/pci@800000020000002/pci@2,3/usb@1/hub@1
/pci@800000020000002/pci@2,3/usb@1,1/hub@1

Strangely, though, sometimes the following appears,
and I don't quite understand why.
/interrupt-controller@3fe0000a400

A typical stack trace:
Vector: 300 (Data Access) at [c0000000555637d0]
pc: c000000000202a50: .dlpar_add_slot+0x108/0x410
c000000000202e78 .add_slot_store+0x7c/0xac
c000000000202da0 .dlpar_attr_store+0x48/0x64
c0000000000f8ee4 .sysfs_write_file+0x100/0x1a0

A similar stack trace is involved for the slot remove.

This code survived testing, of adding and removing different slots,
23 times each, so far, as of this writing.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>

Index: linux-2.6.14-rc2-git6/arch/ppc64/kernel/pSeries_iommu.c
===================================================================
--- linux-2.6.14-rc2-git6.orig/arch/ppc64/kernel/pSeries_iommu.c 2005-10-06 17:50:28.197206873 -0500
+++ linux-2.6.14-rc2-git6/arch/ppc64/kernel/pSeries_iommu.c 2005-10-06 17:53:46.650361968 -0500
@@ -478,10 +478,13 @@
{
int err = NOTIFY_OK;
struct device_node *np = node;
- struct pci_dn *pci = np->data;
+ struct pci_dn *pci;

switch (action) {
case PSERIES_RECONFIG_REMOVE:
+ pci = PCI_DN(np);
+ if (!pci)
+ return NOTIFY_OK;
if (pci->iommu_table &&
get_property(np, "ibm,dma-window", NULL))
iommu_free_table(np);
Index: linux-2.6.14-rc2-git6/arch/ppc64/kernel/pci_dn.c
===================================================================
--- linux-2.6.14-rc2-git6.orig/arch/ppc64/kernel/pci_dn.c 2005-10-06 17:50:28.198206733 -0500
+++ linux-2.6.14-rc2-git6/arch/ppc64/kernel/pci_dn.c 2005-10-06 17:53:46.660360565 -0500
@@ -195,7 +195,10 @@

switch (action) {
case PSERIES_RECONFIG_ADD:
- pci = np->parent->data;
+ pci = PCI_DN(np->parent);
+ if (!pci)
+ return NOTIFY_OK;
+
update_dn_pci_info(np, pci->phb);
break;