- 21 6月, 2016 1 次提交
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由 Jon Derrick 提交于
Enabling interrupts may result in an interrupt raised and serviced while VMD holds a lock, resulting in contention with the spin lock held while enabling interrupts. The solution is to disable preemption and save/restore the state during interrupt enable and disable. Fixes lockdep: ====================================================== [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ] 4.6.0-2016-06-16-lockdep+ #47 Tainted: G E ------------------------------------------------------ kworker/0:1/447 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: (list_lock){+.+...}, at: [<ffffffffa04eb8fc>] vmd_irq_enable+0x3c/0x70 [vmd] and this task is already holding: (&irq_desc_lock_class){-.-...}, at: [<ffffffff810e1ff6>] __setup_irq+0xa6/0x610 which would create a new lock dependency: (&irq_desc_lock_class){-.-...} -> (list_lock){+.+...} but this new dependency connects a HARDIRQ-irq-safe lock: (&irq_desc_lock_class){-.-...} ... which became HARDIRQ-irq-safe at: [<ffffffff810c9f21>] __lock_acquire+0x981/0xe00 [<ffffffff810cb039>] lock_acquire+0x119/0x220 [<ffffffff8167294d>] _raw_spin_lock+0x3d/0x80 [<ffffffff810e36d4>] handle_level_irq+0x24/0x110 [<ffffffff8101f20a>] handle_irq+0x1a/0x30 [<ffffffff81675fc1>] do_IRQ+0x61/0x120 [<ffffffff8167404c>] ret_from_intr+0x0/0x20 [<ffffffff81672e30>] _raw_spin_unlock_irqrestore+0x40/0x60 [<ffffffff810e21ee>] __setup_irq+0x29e/0x610 [<ffffffff810e25a1>] setup_irq+0x41/0x90 [<ffffffff81f5777f>] setup_default_timer_irq+0x1e/0x20 [<ffffffff81f57798>] hpet_time_init+0x17/0x19 [<ffffffff81f5775a>] x86_late_time_init+0xa/0x11 [<ffffffff81f51e9b>] start_kernel+0x382/0x436 [<ffffffff81f51308>] x86_64_start_reservations+0x2a/0x2c [<ffffffff81f51445>] x86_64_start_kernel+0x13b/0x14a to a HARDIRQ-irq-unsafe lock: (list_lock){+.+...} ... which became HARDIRQ-irq-unsafe at: ... [<ffffffff810c9d8e>] __lock_acquire+0x7ee/0xe00 [<ffffffff810cb039>] lock_acquire+0x119/0x220 [<ffffffff8167294d>] _raw_spin_lock+0x3d/0x80 [<ffffffffa04eba42>] vmd_msi_init+0x72/0x150 [vmd] [<ffffffff810e8597>] msi_domain_alloc+0xb7/0x140 [<ffffffff810e6b10>] irq_domain_alloc_irqs_recursive+0x40/0xa0 [<ffffffff810e6cea>] __irq_domain_alloc_irqs+0x14a/0x330 [<ffffffff810e8a8c>] msi_domain_alloc_irqs+0x8c/0x1d0 [<ffffffff813ca4e3>] pci_msi_setup_msi_irqs+0x43/0x70 [<ffffffff813cada1>] pci_enable_msi_range+0x131/0x280 [<ffffffff813bf5e0>] pcie_port_device_register+0x320/0x4e0 [<ffffffff813bf9a4>] pcie_portdrv_probe+0x34/0x60 [<ffffffff813b0e85>] local_pci_probe+0x45/0xa0 [<ffffffff813b226b>] pci_device_probe+0xdb/0x130 [<ffffffff8149e3cc>] driver_probe_device+0x22c/0x440 [<ffffffff8149e774>] __device_attach_driver+0x94/0x110 [<ffffffff8149bfad>] bus_for_each_drv+0x5d/0x90 [<ffffffff8149e030>] __device_attach+0xc0/0x140 [<ffffffff8149e0c0>] device_attach+0x10/0x20 [<ffffffff813a77f7>] pci_bus_add_device+0x47/0x90 [<ffffffff813a7879>] pci_bus_add_devices+0x39/0x70 [<ffffffff813aaba7>] pci_rescan_bus+0x27/0x30 [<ffffffffa04ec1af>] vmd_probe+0x68f/0x76c [vmd] [<ffffffff813b0e85>] local_pci_probe+0x45/0xa0 [<ffffffff81088064>] work_for_cpu_fn+0x14/0x20 [<ffffffff8108c244>] process_one_work+0x1f4/0x740 [<ffffffff8108c9c6>] worker_thread+0x236/0x4f0 [<ffffffff810935c2>] kthread+0xf2/0x110 [<ffffffff816738f2>] ret_from_fork+0x22/0x50 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(list_lock); local_irq_disable(); lock(&irq_desc_lock_class); lock(list_lock); <Interrupt> lock(&irq_desc_lock_class); *** DEADLOCK *** Signed-off-by: NJon Derrick <jonathan.derrick@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com> Acked-by: NKeith Busch <keith.busch@intel.com>
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- 14 6月, 2016 2 次提交
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由 Keith Busch 提交于
Multiple calls to disable an IRQ would have caused the driver to dereference a poisoned list item. This re-initializes the list to allow multiple requests to disable the IRQ. Signed-off-by: NKeith Busch <keith.busch@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com> Acked-by Jon Derrick: <jonathan.derrick@intel.com>
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由 Keith Busch 提交于
VMD device doesn't usually have device archdata specific dma_ops, so we need to override the default ops for VMD devices. Signed-off-by: NKeith Busch <keith.busch@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com> Acked-by Jon Derrick: <jonathan.derrick@intel.com>
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- 11 3月, 2016 3 次提交
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由 Jon Derrick 提交于
Attach the new VMD domain's resources to the VMD device's resources. This allows /proc/iomem to display a more complete picture. Before: c0000000-c1ffffff : 0000:5d:05.5 c2000000-c3ffffff : 0000:5d:05.5 c2010000-c2013fff : nvme c4000000-c40fffff : 0000:5d:05.5 After: c0000000-c1ffffff : 0000:5d:05.5 c2000000-c3ffffff : 0000:5d:05.5 c2000000-c3ffffff : VMD MEMBAR1 c2000000-c22fffff : PCI Bus 10000:01 c2000000-c200ffff : 10000:01:00.0 c2010000-c2013fff : 10000:01:00.0 c2010000-c2013fff : nvme c2300000-c24fffff : PCI Bus 10000:01 c4000000-c40fffff : 0000:5d:05.5 c4002000-c40fffff : VMD MEMBAR2 Signed-off-by: NJon Derrick <jonathan.derrick@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com> Reviewed-by: NKeith Busch <keith.busch@intel.com>
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由 Keith Busch 提交于
The bus always starts at 0. Due to alignment and down-casting, this happened to work before, but looked alarmingly incorrect in kernel logs. Signed-off-by: NKeith Busch <keith.busch@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
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由 Keith Busch 提交于
Comment the less obvious portion of the code for setting up memory windows, and the platform dependency for initializing the h/w with appropriate resources. Signed-off-by: NKeith Busch <keith.busch@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
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- 16 1月, 2016 1 次提交
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由 Keith Busch 提交于
The Intel Volume Management Device (VMD) is a Root Complex Integrated Endpoint that acts as a host bridge to a secondary PCIe domain. BIOS can reassign one or more Root Ports to appear within a VMD domain instead of the primary domain. The immediate benefit is that additional PCIe domains allow more than 256 buses in a system by letting bus numbers be reused across different domains. VMD domains do not define ACPI _SEG, so to avoid domain clashing with host bridges defining this segment, VMD domains start at 0x10000, which is greater than the highest possible 16-bit ACPI defined _SEG. This driver enumerates and enables the domain using the root bus configuration interface provided by the PCI subsystem. The driver provides configuration space accessor functions (pci_ops), bus and memory resources, an MSI IRQ domain with irq_chip implementation, and DMA operations necessary to use devices through the VMD endpoint's interface. VMD routes I/O as follows: 1) Configuration Space: BAR 0 ("CFGBAR") of VMD provides the base address and size for configuration space register access to VMD-owned root ports. It works similarly to MMCONFIG for extended configuration space. Bus numbering is independent and does not conflict with the primary domain. 2) MMIO Space: BARs 2 and 4 ("MEMBAR1" and "MEMBAR2") of VMD provide the base address, size, and type for MMIO register access. These addresses are not translated by VMD hardware; they are simply reservations to be distributed to root ports' memory base/limit registers and subdivided among devices downstream. 3) DMA: To interact appropriately with an IOMMU, the source ID DMA read and write requests are translated to the bus-device-function of the VMD endpoint. Otherwise, DMA operates normally without VMD-specific address translation. 4) Interrupts: Part of VMD's BAR 4 is reserved for VMD's MSI-X Table and PBA. MSIs from VMD domain devices and ports are remapped to appear as if they were issued using one of VMD's MSI-X table entries. Each MSI and MSI-X address of VMD-owned devices and ports has a special format where the address refers to specific entries in the VMD's MSI-X table. As with DMA, the interrupt source ID is translated to VMD's bus-device-function. The driver provides its own MSI and MSI-X configuration functions specific to how MSI messages are used within the VMD domain, and provides an irq_chip for independent IRQ allocation to relay interrupts from VMD's interrupt handler to the appropriate device driver's handler. 5) Errors: PCIe error message are intercepted by the root ports normally (e.g., AER), except with VMD, system errors (i.e., firmware first) are disabled by default. AER and hotplug interrupts are translated in the same way as endpoint interrupts. 6) VMD does not support INTx interrupts or IO ports. Devices or drivers requiring these features should either not be placed below VMD-owned root ports, or VMD should be disabled by BIOS for such endpoints. [bhelgaas: add VMD BAR #defines, factor out vmd_cfg_addr(), rework VMD resource setup, whitespace, changelog] Signed-off-by: NKeith Busch <keith.busch@intel.com> Signed-off-by: NBjorn Helgaas <bhelgaas@google.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> (IRQ-related parts)
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