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>
This commit is contained in:
Gavin Shan 2014-11-12 13:36:11 +11:00 committed by Michael Ellerman
parent ec8e4e9d3d
commit cf2b1e0eb0

View File

@ -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") ||