Mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ https://git.shady.money/linux/atom?h=v3.8 2013-01-14T17:23:22Z 2013-01-14T17:23:22Z Bjorn Helgaas bhelgaas@google.com 2013-01-11T19:21:15Z urn:sha1:f652e7d2916fe2fcf9e7d709aa5b7476b431e2dd When we have an SHPC-capable bridge with a second SHPC-capable bridge below it, pushing the upstream bridge's attention button causes a deadlock. The deadlock happens because we use the shpchp_wq workqueue to run shpchp_pushbutton_thread(), which uses shpchp_disable_slot() to remove devices below the upstream bridge. When we remove the downstream bridge, we call shpc_remove(), the shpchp driver's .remove() method. That calls flush_workqueue(shpchp_wq), which deadlocks because the shpchp_pushbutton_thread() work item is still running. This patch avoids the deadlock by creating a workqueue for every slot and removing the single shared workqueue. Here's the call path that leads to the deadlock: shpchp_queue_pushbutton_work queue_work(shpchp_wq) # shpchp_pushbutton_thread ... shpchp_pushbutton_thread shpchp_disable_slot remove_board shpchp_unconfigure_device pci_stop_and_remove_bus_device ... shpc_remove # shpchp driver .remove method hpc_release_ctlr cleanup_slots flush_workqueue(shpchp_wq) This change is based on code inspection, since we don't have hardware with this topology. Based-on-patch-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org 2013-01-14T17:23:07Z Bjorn Helgaas bhelgaas@google.com 2013-01-11T19:07:22Z urn:sha1:d347e75847c1fb299c97736638f45e6ea39702d4 Use non-ordered workqueue for attention button events. Attention button events on each slot can be handled asynchronously. So we should use non-ordered workqueue. This patch also removes ordered workqueue in shpchp as a result. 486b10b9f4 ("PCI: pciehp: Handle push button event asynchronously") made the same change to pciehp. I split this out from a patch by Yijing Wang <wangyijing@huawei.com> so we fix one thing at a time and to make the shpchp history correspond more closely with the pciehp history. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> 2013-01-13T23:16:03Z Bjorn Helgaas bhelgaas@google.com 2013-01-11T22:30:52Z urn:sha1:10959d72d401cec2781ca636b07d692c625e1c91 e24dcbef93 ("shpchp: update workqueue usage") was described as adding non-ordered shpchp_wq, but it actually made it an *ordered* workqueue. This patch changes shpchp_wq to be non-ordered, as described in the e24dcbef93 commit log and as was done for pciehp by a827ea307b ("pciehp: update workqueue usage"). Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Tejun Heo <tj@kernel.org> 2013-01-12T20:56:33Z Yijing Wang wangyijing@huawei.com 2013-01-11T02:15:54Z urn:sha1:c2be6f93b383c873a4f9d521afa49b1b67d06085 When we have a hotplug-capable PCIe port with a second hotplug-capable PCIe port below it, removing the device below the upstream port causes a deadlock. The deadlock happens because we use the pciehp_wq workqueue to run pciehp_power_thread(), which uses pciehp_disable_slot() to remove devices below the upstream port. When we remove the downstream PCIe port, we call pciehp_remove(), the pciehp driver's .remove() method. That calls flush_workqueue(pciehp_wq), which deadlocks because the pciehp_power_thread() work item is still running. This patch avoids the deadlock by creating a workqueue for every PCIe port and removing the single shared workqueue. Here's the call path that leads to the deadlock: pciehp_queue_pushbutton_work queue_work(pciehp_wq) # queue pciehp_power_thread ... pciehp_power_thread pciehp_disable_slot remove_board pciehp_unconfigure_device pci_stop_and_remove_bus_device ... pciehp_remove # pciehp driver .remove method pciehp_release_ctrl pcie_cleanup_slot flush_workqueue(pciehp_wq) This is fairly urgent because it can be caused by simply unplugging a Thunderbolt adapter, as reported by Daniel below. [bhelgaas: changelog] Reference: http://lkml.kernel.org/r/CAMVG2ssiRgcTD1bej2tkUUfsWmpL5eNtPcNif9va2-Gzb2u8nQ@mail.gmail.com Reported-and-tested-by: Daniel J Blueman <daniel@quora.org> Reviewed-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> Signed-off-by: Yijing Wang <wangyijing@huawei.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: stable@vger.kernel.org 2012-12-13T22:20:19Z Linus Torvalds torvalds@linux-foundation.org 2012-12-13T22:20:19Z urn:sha1:c7708fac5a878d6e0f2de0aa19f9749cff4f707f Pull s390 update from Martin Schwidefsky: "Add support to generate code for the latest machine zEC12, MOD and XOR instruction support for the BPF jit compiler, the dasd safe offline feature and the big one: the s390 architecture gets PCI support!! Right before the world ends on the 21st ;-)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (41 commits) s390/qdio: rename the misleading PCI flag of qdio devices s390/pci: remove obsolete email addresses s390/pci: speed up __iowrite64_copy by using pci store block insn s390/pci: enable NEED_DMA_MAP_STATE s390/pci: no msleep in potential IRQ context s390/pci: fix potential NULL pointer dereference in dma_free_seg_table() s390/pci: use kmem_cache_zalloc instead of kmem_cache_alloc/memset s390/bpf,jit: add support for XOR instruction s390/bpf,jit: add support MOD instruction s390/cio: fix pgid reserved check vga: compile fix, disable vga for s390 s390/pci: add PCI Kconfig options s390/pci: s390 specific PCI sysfs attributes s390/pci: PCI hotplug support via SCLP s390/pci: CHSC PCI support for error and availability events s390/pci: DMA support s390/pci: PCI adapter interrupts for MSI/MSI-X s390/bitops: find leftmost bit instruction support s390/pci: CLP interface s390/pci: base support ... 2012-11-30T16:47:25Z Jan Glauber jang@linux.vnet.ibm.com 2012-11-29T13:35:47Z urn:sha1:7441b0627e2251370902305a204e1330a696ca04 Add SCLP PCI configure/deconfigure and implement a PCI hotplug controller (s390_pci_hpc). The hotplug controller creates a slot for every PCI function in stand-by or configured state. The PCI functions are named after the PCI function ID (fid). By writing to the power attribute in /sys/bus/pci/slots/<fid>/power the PCI function is moved to stand-by or configured state. If moved to the configured state the device is automatically scanned by the s390 PCI layer. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> 2012-11-28T21:16:47Z Bill Pemberton wfp5p@virginia.edu 2012-11-21T20:35:00Z urn:sha1:15856ad50bf5ea02a5ee22399c036d49e7e1124d CONFIG_HOTPLUG is going away as an option so __devexit_p, __devint, __devinitdata, __devinitconst, and _devexit are no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 2012-10-05T18:16:12Z Linus Torvalds torvalds@linux-foundation.org 2012-10-05T18:16:12Z urn:sha1:5f3d2f2e1a63679cf1c4a4210f2f1cc2f335bef6 Pull powerpc updates from Benjamin Herrenschmidt: "Some highlights in addition to the usual batch of fixes: - 64TB address space support for 64-bit processes by Aneesh Kumar - Gavin Shan did a major cleanup & re-organization of our EEH support code (IBM fancy PCI error handling & recovery infrastructure) which paves the way for supporting different platform backends, along with some rework of the PCIe code for the PowerNV platform in order to remove home made resource allocations and instead use the generic code (which is possible after some small improvements to it done by Gavin). - Uprobes support by Ananth N Mavinakayanahalli - A pile of embedded updates from Freescale folks, including new SoC and board supports, more KVM stuff including preparing for 64-bit BookE KVM support, ePAPR 1.1 updates, etc..." Fixup trivial conflicts in drivers/scsi/ipr.c * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (146 commits) powerpc/iommu: Fix multiple issues with IOMMU pools code powerpc: Fix VMX fix for memcpy case driver/mtd:IFC NAND:Initialise internal SRAM before any write powerpc/fsl-pci: use 'Header Type' to identify PCIE mode powerpc/eeh: Don't release eeh_mutex in eeh_phb_pe_get powerpc: Remove tlb batching hack for nighthawk powerpc: Set paca->data_offset = 0 for boot cpu powerpc/perf: Sample only if SIAR-Valid bit is set in P7+ powerpc/fsl-pci: fix warning when CONFIG_SWIOTLB is disabled powerpc/mpc85xx: Update interrupt handling for IFC controller powerpc/85xx: Enable USB support in p1023rds_defconfig powerpc/smp: Do not disable IPI interrupts during suspend powerpc/eeh: Fix crash on converting OF node to edev powerpc/eeh: Lock module while handling EEH event powerpc/kprobe: Don't emulate store when kprobe stwu r1 powerpc/kprobe: Complete kprobe and migrate exception frame powerpc/kprobe: Introduce a new thread flag powerpc: Remove unused __get_user64() and __put_user64() powerpc/eeh: Global mutex to protect PE tree powerpc/eeh: Remove EEH PE for normal PCI hotplug ... 2012-09-24T22:36:48Z Bjorn Helgaas bhelgaas@google.com 2012-09-24T22:36:48Z urn:sha1:d3ce52f50cc1697504130897f1d7c489b62dae1c 2012-09-24T22:36:10Z Bjorn Helgaas bhelgaas@google.com 2012-09-24T22:36:10Z urn:sha1:18d63c35a265465b7137c4ea9c6b135aada13c3c