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authorGavin Shan <gwshan@linux.vnet.ibm.com>2014-11-12 13:36:11 +1100
committerMichael Ellerman <mpe@ellerman.id.au>2014-11-14 17:24:25 +1100
commitcf2b1e0eb0c281122b001cc879ca0118bff71255 (patch)
tree1507182116826675e204a2352ecee75bfa32dda7
parentec8e4e9d3d83b7a973477c2cb4831511b0eec06e (diff)
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op-kernel-dev-cf2b1e0eb0c281122b001cc879ca0118bff71255.tar.gz
powerpc/powernv: Fix potential zero devisor
If there're no PHBs under P5IOC2 HUB device tree node, we should bail early to avoid zero devisor and allocating TCE tables. Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
-rw-r--r--arch/powerpc/platforms/powernv/pci-p5ioc2.c28
1 files changed, 16 insertions, 12 deletions
diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index 94ce348..3336fcb 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -196,6 +196,22 @@ void __init pnv_pci_init_p5ioc2_hub(struct device_node *np)
hub_id = be64_to_cpup(prop64);
pr_info(" HUB-ID : 0x%016llx\n", hub_id);
+ /* Count child PHBs and calculate TCE space per PHB */
+ for_each_child_of_node(np, phbn) {
+ if (of_device_is_compatible(phbn, "ibm,p5ioc2-pcix") ||
+ of_device_is_compatible(phbn, "ibm,p5ioc2-pciex"))
+ phb_count++;
+ }
+
+ if (phb_count <= 0) {
+ pr_info(" No PHBs for Hub %s\n", np->full_name);
+ return;
+ }
+
+ tce_per_phb = __rounddown_pow_of_two(P5IOC2_TCE_MEMORY / phb_count);
+ pr_info(" Allocating %lld MB of TCE memory per PHB\n",
+ tce_per_phb >> 20);
+
/* Currently allocate 16M of TCE memory for every Hub
*
* XXX TODO: Make it chip local if possible
@@ -215,18 +231,6 @@ void __init pnv_pci_init_p5ioc2_hub(struct device_node *np)
return;
}
- /* Count child PHBs */
- for_each_child_of_node(np, phbn) {
- if (of_device_is_compatible(phbn, "ibm,p5ioc2-pcix") ||
- of_device_is_compatible(phbn, "ibm,p5ioc2-pciex"))
- phb_count++;
- }
-
- /* Calculate how much TCE space we can give per PHB */
- tce_per_phb = __rounddown_pow_of_two(P5IOC2_TCE_MEMORY / phb_count);
- pr_info(" Allocating %lld MB of TCE memory per PHB\n",
- tce_per_phb >> 20);
-
/* Initialize PHBs */
for_each_child_of_node(np, phbn) {
if (of_device_is_compatible(phbn, "ibm,p5ioc2-pcix") ||
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