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* intel-iommu: fix superpage support in pfn_to_dma_pte()Allen Kay2011-10-19
| | | | | | | | | | If target_level == 0, current code breaks out of the while-loop if SUPERPAGE bit is set. We should also break out if PTE is not present. If we don't do this, KVM calls to iommu_iova_to_phys() will cause pfn_to_dma_pte() to create mapping for 4KiB pages. Signed-off-by: Allen Kay <allen.m.kay@intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* intel-iommu: set iommu_superpage on VM domains to lowest common denominatorAllen Kay2011-10-19
| | | | | | | | | | | set dmar->iommu_superpage field to the smallest common denominator of super page sizes supported by all active VT-d engines. Initialize this field in intel_iommu_domain_init() API so intel_iommu_map() API will be able to use iommu_superpage field to determine the appropriate super page size to use. Signed-off-by: Allen Kay <allen.m.kay@intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* intel-iommu: fix return value of iommu_unmap() APIAllen Kay2011-10-19
| | | | | | | | | iommu_unmap() API expects IOMMU drivers to return the actual page order of the address being unmapped. Previous code was just returning page order passed in from the caller. This patch fixes this problem. Signed-off-by: Allen Kay <allen.m.kay@intel.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* intel-iommu: Export a flag indicating that the IOMMU is used for iGFX.David Woodhouse2011-10-14
| | | | | | | | | | | We really don't want this to work in the general case; device drivers *shouldn't* care whether they are behind an IOMMU or not. But the integrated graphics is a special case, because the IOMMU and the GTT are all kind of smashed into one and generally horrifically buggy, so it's reasonable for the graphics driver to want to know when the IOMMU is active for the graphics hardware. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* intel-iommu: Workaround IOTLB hang on Ironlake GPUDavid Woodhouse2011-10-14
| | | | | | | | | | To work around a hardware issue, we have to submit IOTLB flushes while the graphics engine is idle. The graphics driver will (we hope) go to great lengths to ensure that it gets that right on the affected chipset(s)... so let's not screw it over by deferring the unmap and doing it later. That wouldn't be very helpful. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* intel-iommu: Fix AB-BA lockdep reportRoland Dreier2011-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When unbinding a device so that I could pass it through to a KVM VM, I got the lockdep report below. It looks like a legitimate lock ordering problem: - domain_context_mapping_one() takes iommu->lock and calls iommu_support_dev_iotlb(), which takes device_domain_lock (inside iommu->lock). - domain_remove_one_dev_info() starts by taking device_domain_lock then takes iommu->lock inside it (near the end of the function). So this is the classic AB-BA deadlock. It looks like a safe fix is to simply release device_domain_lock a bit earlier, since as far as I can tell, it doesn't protect any of the stuff accessed at the end of domain_remove_one_dev_info() anyway. BTW, the use of device_domain_lock looks a bit unsafe to me... it's at least not obvious to me why we aren't vulnerable to the race below: iommu_support_dev_iotlb() domain_remove_dev_info() lock device_domain_lock find info unlock device_domain_lock lock device_domain_lock find same info unlock device_domain_lock free_devinfo_mem(info) do stuff with info after it's free However I don't understand the locking here well enough to know if this is a real problem, let alone what the best fix is. Anyway here's the full lockdep output that prompted all of this: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.39.1+ #1 ------------------------------------------------------- bash/13954 is trying to acquire lock: (&(&iommu->lock)->rlock){......}, at: [<ffffffff812f6421>] domain_remove_one_dev_info+0x121/0x230 but task is already holding lock: (device_domain_lock){-.-...}, at: [<ffffffff812f6508>] domain_remove_one_dev_info+0x208/0x230 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (device_domain_lock){-.-...}: [<ffffffff8109ca9d>] lock_acquire+0x9d/0x130 [<ffffffff81571475>] _raw_spin_lock_irqsave+0x55/0xa0 [<ffffffff812f8350>] domain_context_mapping_one+0x600/0x750 [<ffffffff812f84df>] domain_context_mapping+0x3f/0x120 [<ffffffff812f9175>] iommu_prepare_identity_map+0x1c5/0x1e0 [<ffffffff81ccf1ca>] intel_iommu_init+0x88e/0xb5e [<ffffffff81cab204>] pci_iommu_init+0x16/0x41 [<ffffffff81002165>] do_one_initcall+0x45/0x190 [<ffffffff81ca3d3f>] kernel_init+0xe3/0x168 [<ffffffff8157ac24>] kernel_thread_helper+0x4/0x10 -> #0 (&(&iommu->lock)->rlock){......}: [<ffffffff8109bf3e>] __lock_acquire+0x195e/0x1e10 [<ffffffff8109ca9d>] lock_acquire+0x9d/0x130 [<ffffffff81571475>] _raw_spin_lock_irqsave+0x55/0xa0 [<ffffffff812f6421>] domain_remove_one_dev_info+0x121/0x230 [<ffffffff812f8b42>] device_notifier+0x72/0x90 [<ffffffff8157555c>] notifier_call_chain+0x8c/0xc0 [<ffffffff81089768>] __blocking_notifier_call_chain+0x78/0xb0 [<ffffffff810897b6>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff81373a5c>] __device_release_driver+0xbc/0xe0 [<ffffffff81373ccf>] device_release_driver+0x2f/0x50 [<ffffffff81372ee3>] driver_unbind+0xa3/0xc0 [<ffffffff813724ac>] drv_attr_store+0x2c/0x30 [<ffffffff811e4506>] sysfs_write_file+0xe6/0x170 [<ffffffff8117569e>] vfs_write+0xce/0x190 [<ffffffff811759e4>] sys_write+0x54/0xa0 [<ffffffff81579a82>] system_call_fastpath+0x16/0x1b other info that might help us debug this: 6 locks held by bash/13954: #0: (&buffer->mutex){+.+.+.}, at: [<ffffffff811e4464>] sysfs_write_file+0x44/0x170 #1: (s_active#3){++++.+}, at: [<ffffffff811e44ed>] sysfs_write_file+0xcd/0x170 #2: (&__lockdep_no_validate__){+.+.+.}, at: [<ffffffff81372edb>] driver_unbind+0x9b/0xc0 #3: (&__lockdep_no_validate__){+.+.+.}, at: [<ffffffff81373cc7>] device_release_driver+0x27/0x50 #4: (&(&priv->bus_notifier)->rwsem){.+.+.+}, at: [<ffffffff8108974f>] __blocking_notifier_call_chain+0x5f/0xb0 #5: (device_domain_lock){-.-...}, at: [<ffffffff812f6508>] domain_remove_one_dev_info+0x208/0x230 stack backtrace: Pid: 13954, comm: bash Not tainted 2.6.39.1+ #1 Call Trace: [<ffffffff810993a7>] print_circular_bug+0xf7/0x100 [<ffffffff8109bf3e>] __lock_acquire+0x195e/0x1e10 [<ffffffff810972bd>] ? trace_hardirqs_off+0xd/0x10 [<ffffffff8109d57d>] ? trace_hardirqs_on_caller+0x13d/0x180 [<ffffffff8109ca9d>] lock_acquire+0x9d/0x130 [<ffffffff812f6421>] ? domain_remove_one_dev_info+0x121/0x230 [<ffffffff81571475>] _raw_spin_lock_irqsave+0x55/0xa0 [<ffffffff812f6421>] ? domain_remove_one_dev_info+0x121/0x230 [<ffffffff810972bd>] ? trace_hardirqs_off+0xd/0x10 [<ffffffff812f6421>] domain_remove_one_dev_info+0x121/0x230 [<ffffffff812f8b42>] device_notifier+0x72/0x90 [<ffffffff8157555c>] notifier_call_chain+0x8c/0xc0 [<ffffffff81089768>] __blocking_notifier_call_chain+0x78/0xb0 [<ffffffff810897b6>] blocking_notifier_call_chain+0x16/0x20 [<ffffffff81373a5c>] __device_release_driver+0xbc/0xe0 [<ffffffff81373ccf>] device_release_driver+0x2f/0x50 [<ffffffff81372ee3>] driver_unbind+0xa3/0xc0 [<ffffffff813724ac>] drv_attr_store+0x2c/0x30 [<ffffffff811e4506>] sysfs_write_file+0xe6/0x170 [<ffffffff8117569e>] vfs_write+0xce/0x190 [<ffffffff811759e4>] sys_write+0x54/0xa0 [<ffffffff81579a82>] system_call_fastpath+0x16/0x1b Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
* x86, iommu: Mark DMAR IRQ as non-threadedThomas Gleixner2011-09-13
| | | | | | | | | | | Mark this lowlevel IRQ handler as non-threaded. This prevents a boot crash when "threadirqs" is on the kernel commandline. Also the interrupt handler is handling hardware critical events which should not be delayed into a thread. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* iommu/amd: Don't take domain->lock recursivlyJoerg Roedel2011-09-02
| | | | | | | | | | | The domain_flush_devices() function takes the domain->lock. But this function is only called from update_domain() which itself is already called unter the domain->lock. This causes a deadlock situation when the dma-address-space of a domain grows larger than 1GB. Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* iommu/amd: Make sure iommu->need_sync contains correct valueJoerg Roedel2011-09-02
| | | | | | | | | The value is only set to true but never set back to false, which causes to many completion-wait commands to be sent to hardware. Fix it with this patch. Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* iommu/amd: Don't use MSI address range for DMA addressesJoerg Roedel2011-07-06
| | | | | | | | Reserve the MSI address range in the address allocator so that MSI addresses are not handed out as dma handles. Cc: stable@kernel.org Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* Merge branches 'amd/transparent-bridge' and 'core'Joerg Roedel2011-06-21
| | | | | | | | Conflicts: arch/x86/include/asm/amd_iommu_types.h arch/x86/kernel/amd_iommu.c Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* iommu/amd: Move missing parts to drivers/iommuJoerg Roedel2011-06-21
| | | | | | | | A few parts of the driver were missing in drivers/iommu. Move them there to have the complete driver in that directory. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* iommu: Move iommu Kconfig entries to submenuJoerg Roedel2011-06-21
| | | | | | | For better navigation this patch moves the drivers/iommu drivers into its own submenu in Kconfig. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* x86/ia64: intel-iommu: move to drivers/iommu/Ohad Ben-Cohen2011-06-21
| | | | | | | | | | | | | | | | | This should ease finding similarities with different platforms, with the intention of solving problems once in a generic framework which everyone can use. Note: to move intel-iommu.c, the declaration of pci_find_upstream_pcie_bridge() has to move from drivers/pci/pci.h to include/linux/pci.h. This is handled in this patch, too. As suggested, also drop DMAR's EXPERIMENTAL tag while we're at it. Compile-tested on x86_64. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* x86: amd_iommu: move to drivers/iommu/Ohad Ben-Cohen2011-06-21
| | | | | | | | | | | This should ease finding similarities with different platforms, with the intention of solving problems once in a generic framework which everyone can use. Compile-tested on x86_64. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* msm: iommu: move to drivers/iommu/Ohad Ben-Cohen2011-06-21
| | | | | | | | | | | | This should ease finding similarities with different platforms, with the intention of solving problems once in a generic framework which everyone can use. Compile-tested for MSM8X60. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Acked-by: David Brown <davidb@codeaurora.org> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
* drivers: iommu: move to a dedicated folderOhad Ben-Cohen2011-06-14
Create a dedicated folder for iommu drivers, and move the base iommu implementation over there. Grouping the various iommu drivers in a single location will help finding similar problems shared by different platforms, so they could be solved once, in the iommu framework, instead of solved differently (or duplicated) in each driver. Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com> Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>