This is a note to let you know that I've just added the patch titled powerpc/iommu: Remove IOMMU device references via bus notifier to the 3.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-iommu-remove-iommu-device-references-via-bus-notifier.patch and it can be found in the queue-3.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 4ad04e5987115ece5fa8a0cf1dc72fcd4707e33e Mon Sep 17 00:00:00 2001 From: Nishanth Aravamudan <nacc@xxxxxxxxxxxxxxxxxx> Date: Sat, 21 Feb 2015 11:00:50 -0800 Subject: powerpc/iommu: Remove IOMMU device references via bus notifier From: Nishanth Aravamudan <nacc@xxxxxxxxxxxxxxxxxx> commit 4ad04e5987115ece5fa8a0cf1dc72fcd4707e33e upstream. After d905c5df9aef ("PPC: POWERNV: move iommu_add_device earlier"), the refcnt on the kobject backing the IOMMU group for a PCI device is elevated by each call to pci_dma_dev_setup_pSeriesLP() (via set_iommu_table_base_and_group). When we go to dlpar a multi-function PCI device out: iommu_reconfig_notifier -> iommu_free_table -> iommu_group_put BUG_ON(tbl->it_group) We trip this BUG_ON, because there are still references on the table, so it is not freed. Fix this by moving the powernv bus notifier to common code and calling it for both powernv and pseries. Fixes: d905c5df9aef ("PPC: POWERNV: move iommu_add_device earlier") Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxxxxxxxxxx> Tested-by: Nishanth Aravamudan <nacc@xxxxxxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/powerpc/include/asm/iommu.h | 6 ++++++ arch/powerpc/kernel/iommu.c | 26 ++++++++++++++++++++++++++ arch/powerpc/platforms/powernv/pci.c | 26 -------------------------- arch/powerpc/platforms/pseries/iommu.c | 2 ++ 4 files changed, 34 insertions(+), 26 deletions(-) --- a/arch/powerpc/include/asm/iommu.h +++ b/arch/powerpc/include/asm/iommu.h @@ -113,6 +113,7 @@ extern void iommu_register_group(struct int pci_domain_number, unsigned long pe_num); extern int iommu_add_device(struct device *dev); extern void iommu_del_device(struct device *dev); +extern int __init tce_iommu_bus_notifier_init(void); #else static inline void iommu_register_group(struct iommu_table *tbl, int pci_domain_number, @@ -128,6 +129,11 @@ static inline int iommu_add_device(struc static inline void iommu_del_device(struct device *dev) { } + +static inline int __init tce_iommu_bus_notifier_init(void) +{ + return 0; +} #endif /* !CONFIG_IOMMU_API */ static inline void set_iommu_table_base_and_group(struct device *dev, --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1175,4 +1175,30 @@ void iommu_del_device(struct device *dev } EXPORT_SYMBOL_GPL(iommu_del_device); +static int tce_iommu_bus_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + return iommu_add_device(dev); + case BUS_NOTIFY_DEL_DEVICE: + if (dev->iommu_group) + iommu_del_device(dev); + return 0; + default: + return 0; + } +} + +static struct notifier_block tce_iommu_bus_nb = { + .notifier_call = tce_iommu_bus_notifier, +}; + +int __init tce_iommu_bus_notifier_init(void) +{ + bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb); + return 0; +} #endif /* CONFIG_IOMMU_API */ --- a/arch/powerpc/platforms/powernv/pci.c +++ b/arch/powerpc/platforms/powernv/pci.c @@ -866,30 +866,4 @@ void __init pnv_pci_init(void) #endif } -static int tce_iommu_bus_notifier(struct notifier_block *nb, - unsigned long action, void *data) -{ - struct device *dev = data; - - switch (action) { - case BUS_NOTIFY_ADD_DEVICE: - return iommu_add_device(dev); - case BUS_NOTIFY_DEL_DEVICE: - if (dev->iommu_group) - iommu_del_device(dev); - return 0; - default: - return 0; - } -} - -static struct notifier_block tce_iommu_bus_nb = { - .notifier_call = tce_iommu_bus_notifier, -}; - -static int __init tce_iommu_bus_notifier_init(void) -{ - bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb); - return 0; -} machine_subsys_initcall_sync(powernv, tce_iommu_bus_notifier_init); --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1340,3 +1340,5 @@ static int __init disable_multitce(char } __setup("multitce=", disable_multitce); + +machine_subsys_initcall_sync(pseries, tce_iommu_bus_notifier_init); Patches currently in stable-queue which might be from nacc@xxxxxxxxxxxxxxxxxx are queue-3.19/powerpc-iommu-remove-iommu-device-references-via-bus-notifier.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html