[PATCH v10 13/18] powerpc/pci: Delay populating pdn
Gavin Shan
gwshan at linux.vnet.ibm.com
Thu Jun 23 11:34:32 AEST 2016
On Thu, Jun 23, 2016 at 10:59:57AM +1000, Daniel Axtens wrote:
>Hi,
>
>mpe merged this to his next yesterday, and my nightly scripts picked up
>the following cppcheck warning:
>
>[arch/powerpc/kernel/pci_dn.c:486]: (error) Memory leak: pdn
>
>That goes to the following function:
>
>static void *add_pdn(struct device_node *dn, void *data)
>{
> struct pci_controller *hose = data;
> struct pci_dn *pdn;
>
> pdn = pci_add_device_node_info(hose, dn);
> if (!pdn)
> return ERR_PTR(-ENOMEM);
>
> return NULL;
>}
>
>It looks like this is just called in pci_devs_phb_init_dynamic:
>
> /* Update dn->phb ptrs for new phb and children devices */
> pci_traverse_device_nodes(dn, add_pdn, phb);
>
>So my understanding is that this isn't a real memory leak but just
>cppcheck getting confused.
>
>Gavin, can you confirm that?
>
Daniel, thanks for the report. It's a false alarm: pci_traverse_device_nodes()
will be terminated immediate on non-NULL return value from add_pdn(). So the
function (add_pdn()) returns NULL intentionally. The newly created @pdn has
been attached to @dn. The @pdn is release when the @dn is released in PCI
hot remove time.
>Regards,
>Daniel
>
Thanks,
Gavin
>Gavin Shan <gwshan at linux.vnet.ibm.com> writes:
>
>> The pdn (struct pci_dn) instances are allocated from memblock or
>> bootmem when creating PCI controller (hoses) in setup_arch(). PCI
>> hotplug, which will be supported by proceeding patches, releases
>> PCI device nodes and their corresponding pdn on unplugging event.
>> The memory chunks for pdn instances allocated from memblock or
>> bootmem are hard to reused after being released.
>>
>> This delays creating pdn by pci_devs_phb_init() from setup_arch()
>> to core_initcall() so that they are allocated from slab. The memory
>> consumed by pdn can be released to system without problem during
>> PCI unplugging time. It indicates that pci_dn is unavailable in
>> setup_arch() and the the fixup on pdn (like AGP's) can't be carried
>> out that time. We have to do that in pcibios_root_bridge_prepare()
>> on maple/pasemi/powermac platforms where/when the pdn is available.
>> pcibios_root_bridge_prepare is called from subsys_initcall() which
>> is executed after core_initcall() so the code flow does not change.
>>
>> At the mean while, the EEH device is created when pdn is populated,
>> meaning pdn and EEH device have same life cycle. In turn, we needn't
>> call eeh_dev_init() to create EEH device explicitly.
>>
>> Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
>> Reviewed-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>> ---
>> arch/powerpc/include/asm/eeh.h | 2 +-
>> arch/powerpc/include/asm/ppc-pci.h | 2 --
>> arch/powerpc/kernel/eeh_dev.c | 17 +++------------
>> arch/powerpc/kernel/pci_dn.c | 23 ++++++++++++++++----
>> arch/powerpc/platforms/maple/pci.c | 34 ++++++++++++++++++------------
>> arch/powerpc/platforms/pasemi/pci.c | 3 ---
>> arch/powerpc/platforms/powermac/pci.c | 38 +++++++++++++++++++++-------------
>> arch/powerpc/platforms/powernv/pci.c | 3 ---
>> arch/powerpc/platforms/pseries/setup.c | 6 +-----
>> 9 files changed, 69 insertions(+), 59 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/eeh.h b/arch/powerpc/include/asm/eeh.h
>> index fb9f376..8721580 100644
>> --- a/arch/powerpc/include/asm/eeh.h
>> +++ b/arch/powerpc/include/asm/eeh.h
>> @@ -274,7 +274,7 @@ void eeh_pe_restore_bars(struct eeh_pe *pe);
>> const char *eeh_pe_loc_get(struct eeh_pe *pe);
>> struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe);
>>
>> -void *eeh_dev_init(struct pci_dn *pdn, void *data);
>> +struct eeh_dev *eeh_dev_init(struct pci_dn *pdn);
>> void eeh_dev_phb_init_dynamic(struct pci_controller *phb);
>> int eeh_init(void);
>> int __init eeh_ops_register(struct eeh_ops *ops);
>> diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h
>> index 8753e4e..0f73de0 100644
>> --- a/arch/powerpc/include/asm/ppc-pci.h
>> +++ b/arch/powerpc/include/asm/ppc-pci.h
>> @@ -39,8 +39,6 @@ void *pci_traverse_device_nodes(struct device_node *start,
>> void *traverse_pci_dn(struct pci_dn *root,
>> void *(*fn)(struct pci_dn *, void *),
>> void *data);
>> -
>> -extern void pci_devs_phb_init(void);
>> extern void pci_devs_phb_init_dynamic(struct pci_controller *phb);
>>
>> /* From rtas_pci.h */
>> diff --git a/arch/powerpc/kernel/eeh_dev.c b/arch/powerpc/kernel/eeh_dev.c
>> index 7815095..d6b2ca7 100644
>> --- a/arch/powerpc/kernel/eeh_dev.c
>> +++ b/arch/powerpc/kernel/eeh_dev.c
>> @@ -44,14 +44,13 @@
>> /**
>> * eeh_dev_init - Create EEH device according to OF node
>> * @pdn: PCI device node
>> - * @data: PHB
>> *
>> * It will create EEH device according to the given OF node. The function
>> * might be called by PCI emunation, DR, PHB hotplug.
>> */
>> -void *eeh_dev_init(struct pci_dn *pdn, void *data)
>> +struct eeh_dev *eeh_dev_init(struct pci_dn *pdn)
>> {
>> - struct pci_controller *phb = data;
>> + struct pci_controller *phb = pdn->phb;
>> struct eeh_dev *edev;
>>
>> /* Allocate EEH device */
>> @@ -69,7 +68,7 @@ void *eeh_dev_init(struct pci_dn *pdn, void *data)
>> INIT_LIST_HEAD(&edev->list);
>> INIT_LIST_HEAD(&edev->rmv_list);
>>
>> - return NULL;
>> + return edev;
>> }
>>
>> /**
>> @@ -81,16 +80,8 @@ void *eeh_dev_init(struct pci_dn *pdn, void *data)
>> */
>> void eeh_dev_phb_init_dynamic(struct pci_controller *phb)
>> {
>> - struct pci_dn *root = phb->pci_data;
>> -
>> /* EEH PE for PHB */
>> eeh_phb_pe_create(phb);
>> -
>> - /* EEH device for PHB */
>> - eeh_dev_init(root, phb);
>> -
>> - /* EEH devices for children OF nodes */
>> - traverse_pci_dn(root, eeh_dev_init, phb);
>> }
>>
>> /**
>> @@ -106,8 +97,6 @@ static int __init eeh_dev_phb_init(void)
>> list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
>> eeh_dev_phb_init_dynamic(phb);
>>
>> - pr_info("EEH: devices created\n");
>> -
>> return 0;
>> }
>>
>> diff --git a/arch/powerpc/kernel/pci_dn.c b/arch/powerpc/kernel/pci_dn.c
>> index ecdccce..9cbf95a 100644
>> --- a/arch/powerpc/kernel/pci_dn.c
>> +++ b/arch/powerpc/kernel/pci_dn.c
>> @@ -209,8 +209,7 @@ struct pci_dn *add_dev_pci_data(struct pci_dev *pdev)
>> }
>>
>> /* Create the EEH device for the VF */
>> - eeh_dev_init(pdn, pci_bus_to_host(pdev->bus));
>> - edev = pdn_to_eeh_dev(pdn);
>> + edev = eeh_dev_init(pdn);
>> BUG_ON(!edev);
>> edev->physfn = pdev;
>> }
>> @@ -289,8 +288,11 @@ struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
>> const __be32 *regs;
>> struct device_node *parent;
>> struct pci_dn *pdn;
>> +#ifdef CONFIG_EEH
>> + struct eeh_dev *edev;
>> +#endif
>>
>> - pdn = zalloc_maybe_bootmem(sizeof(*pdn), GFP_KERNEL);
>> + pdn = kzalloc(sizeof(*pdn), GFP_KERNEL);
>> if (pdn == NULL)
>> return NULL;
>> dn->data = pdn;
>> @@ -319,6 +321,15 @@ struct pci_dn *pci_add_device_node_info(struct pci_controller *hose,
>> /* Extended config space */
>> pdn->pci_ext_config_space = (type && of_read_number(type, 1) == 1);
>>
>> + /* Create EEH device */
>> +#ifdef CONFIG_EEH
>> + edev = eeh_dev_init(pdn);
>> + if (!edev) {
>> + kfree(pdn);
>> + return NULL;
>> + }
>> +#endif
>> +
>> /* Attach to parent node */
>> INIT_LIST_HEAD(&pdn->child_list);
>> INIT_LIST_HEAD(&pdn->list);
>> @@ -504,15 +515,19 @@ void pci_devs_phb_init_dynamic(struct pci_controller *phb)
>> * pci device found underneath. This routine runs once,
>> * early in the boot sequence.
>> */
>> -void __init pci_devs_phb_init(void)
>> +static int __init pci_devs_phb_init(void)
>> {
>> struct pci_controller *phb, *tmp;
>>
>> /* This must be done first so the device nodes have valid pci info! */
>> list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
>> pci_devs_phb_init_dynamic(phb);
>> +
>> + return 0;
>> }
>>
>> +core_initcall(pci_devs_phb_init);
>> +
>> static void pci_dev_pdn_setup(struct pci_dev *pdev)
>> {
>> struct pci_dn *pdn;
>> diff --git a/arch/powerpc/platforms/maple/pci.c b/arch/powerpc/platforms/maple/pci.c
>> index a923230..a2f89e6 100644
>> --- a/arch/powerpc/platforms/maple/pci.c
>> +++ b/arch/powerpc/platforms/maple/pci.c
>> @@ -568,6 +568,26 @@ void maple_pci_irq_fixup(struct pci_dev *dev)
>> DBG(" <- maple_pci_irq_fixup\n");
>> }
>>
>> +static int maple_pci_root_bridge_prepare(struct pci_host_bridge *bridge)
>> +{
>> + struct pci_controller *hose = pci_bus_to_host(bridge->bus);
>> + struct device_node *np, *child;
>> +
>> + if (hose != u3_agp)
>> + return 0;
>> +
>> + /* Fixup the PCI<->OF mapping for U3 AGP due to bus renumbering. We
>> + * assume there is no P2P bridge on the AGP bus, which should be a
>> + * safe assumptions hopefully.
>> + */
>> + np = hose->dn;
>> + PCI_DN(np)->busno = 0xf0;
>> + for_each_child_of_node(np, child)
>> + PCI_DN(child)->busno = 0xf0;
>> +
>> + return 0;
>> +}
>> +
>> void __init maple_pci_init(void)
>> {
>> struct device_node *np, *root;
>> @@ -605,19 +625,7 @@ void __init maple_pci_init(void)
>> if (ht && maple_add_bridge(ht) != 0)
>> of_node_put(ht);
>>
>> - /* Setup the linkage between OF nodes and PHBs */
>> - pci_devs_phb_init();
>> -
>> - /* Fixup the PCI<->OF mapping for U3 AGP due to bus renumbering. We
>> - * assume there is no P2P bridge on the AGP bus, which should be a
>> - * safe assumptions hopefully.
>> - */
>> - if (u3_agp) {
>> - struct device_node *np = u3_agp->dn;
>> - PCI_DN(np)->busno = 0xf0;
>> - for (np = np->child; np; np = np->sibling)
>> - PCI_DN(np)->busno = 0xf0;
>> - }
>> + ppc_md.pcibios_root_bridge_prepare = maple_pci_root_bridge_prepare;
>>
>> /* Tell pci.c to not change any resource allocations. */
>> pci_add_flags(PCI_PROBE_ONLY);
>> diff --git a/arch/powerpc/platforms/pasemi/pci.c b/arch/powerpc/platforms/pasemi/pci.c
>> index f3a68a0..10c4e8f 100644
>> --- a/arch/powerpc/platforms/pasemi/pci.c
>> +++ b/arch/powerpc/platforms/pasemi/pci.c
>> @@ -229,9 +229,6 @@ void __init pas_pci_init(void)
>> of_node_get(np);
>>
>> of_node_put(root);
>> -
>> - /* Setup the linkage between OF nodes and PHBs */
>> - pci_devs_phb_init();
>> }
>>
>> void __iomem *pasemi_pci_getcfgaddr(struct pci_dev *dev, int offset)
>> diff --git a/arch/powerpc/platforms/powermac/pci.c b/arch/powerpc/platforms/powermac/pci.c
>> index 59ab16f..6e06c3b 100644
>> --- a/arch/powerpc/platforms/powermac/pci.c
>> +++ b/arch/powerpc/platforms/powermac/pci.c
>> @@ -878,6 +878,29 @@ void pmac_pci_irq_fixup(struct pci_dev *dev)
>> #endif /* CONFIG_PPC32 */
>> }
>>
>> +#ifdef CONFIG_PPC64
>> +static int pmac_pci_root_bridge_prepare(struct pci_host_bridge *bridge)
>> +{
>> + struct pci_controller *hose = pci_bus_to_host(bridge->bus);
>> + struct device_node *np, *child;
>> +
>> + if (hose != u3_agp)
>> + return 0;
>> +
>> + /* Fixup the PCI<->OF mapping for U3 AGP due to bus renumbering. We
>> + * assume there is no P2P bridge on the AGP bus, which should be a
>> + * safe assumptions for now. We should do something better in the
>> + * future though
>> + */
>> + np = hose->dn;
>> + PCI_DN(np)->busno = 0xf0;
>> + for_each_child_of_node(np, child)
>> + PCI_DN(child)->busno = 0xf0;
>> +
>> + return 0;
>> +}
>> +#endif /* CONFIG_PPC64 */
>> +
>> void __init pmac_pci_init(void)
>> {
>> struct device_node *np, *root;
>> @@ -914,20 +937,7 @@ void __init pmac_pci_init(void)
>> if (ht && pmac_add_bridge(ht) != 0)
>> of_node_put(ht);
>>
>> - /* Setup the linkage between OF nodes and PHBs */
>> - pci_devs_phb_init();
>> -
>> - /* Fixup the PCI<->OF mapping for U3 AGP due to bus renumbering. We
>> - * assume there is no P2P bridge on the AGP bus, which should be a
>> - * safe assumptions for now. We should do something better in the
>> - * future though
>> - */
>> - if (u3_agp) {
>> - struct device_node *np = u3_agp->dn;
>> - PCI_DN(np)->busno = 0xf0;
>> - for (np = np->child; np; np = np->sibling)
>> - PCI_DN(np)->busno = 0xf0;
>> - }
>> + ppc_md.pcibios_root_bridge_prepare = pmac_pci_root_bridge_prepare;
>> /* pmac_check_ht_link(); */
>>
>> #else /* CONFIG_PPC64 */
>> diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
>> index b1ee631..0f1b8bf 100644
>> --- a/arch/powerpc/platforms/powernv/pci.c
>> +++ b/arch/powerpc/platforms/powernv/pci.c
>> @@ -816,9 +816,6 @@ void __init pnv_pci_init(void)
>> for_each_compatible_node(np, NULL, "ibm,ioda2-npu-phb")
>> pnv_pci_init_npu_phb(np);
>>
>> - /* Setup the linkage between OF nodes and PHBs */
>> - pci_devs_phb_init();
>> -
>> /* Configure IOMMU DMA hooks */
>> set_pci_dma_ops(&dma_iommu_ops);
>> }
>> diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
>> index 9883bc7..4eada28 100644
>> --- a/arch/powerpc/platforms/pseries/setup.c
>> +++ b/arch/powerpc/platforms/pseries/setup.c
>> @@ -265,11 +265,8 @@ static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long act
>> case OF_RECONFIG_ATTACH_NODE:
>> parent = of_get_parent(np);
>> pdn = parent ? PCI_DN(parent) : NULL;
>> - if (pdn) {
>> - /* Create pdn and EEH device */
>> + if (pdn)
>> pci_add_device_node_info(pdn->phb, np);
>> - eeh_dev_init(PCI_DN(np), pdn->phb);
>> - }
>>
>> of_node_put(parent);
>> break;
>> @@ -492,7 +489,6 @@ static void __init find_and_init_phbs(void)
>> }
>>
>> of_node_put(root);
>> - pci_devs_phb_init();
>>
>> /*
>> * PCI_PROBE_ONLY and PCI_REASSIGN_ALL_BUS can be set via properties
>> --
>> 2.1.0
>>
>> --
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