[PATCH 8/8] powerpc/powernv: Fix potential zero devisor
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STALE4360d
From: Gavin Shan <hidden>
Date: 2014-11-12 02:36:29
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
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 <redacted> Signed-off-by: Gavin Shan <redacted> --- arch/powerpc/platforms/powernv/pci-p5ioc2.c | 28 ++++++++++++++++------------ 1 file 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") ||
--
1.8.3.2