From 360eb3c5687e2df23e29e97878238765bfe6a756 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 6 Jan 2014 14:18:08 +0800 Subject: iommu/vt-d: use dedicated bitmap to track remapping entry allocation status Currently Intel interrupt remapping drivers uses the "present" flag bit in remapping entry to track whether an entry is allocated or not. It works as follow: 1) allocate a remapping entry and set its "present" flag bit to 1 2) compose other fields for the entry 3) update the remapping entry with the composed value The remapping hardware may access the entry between step 1 and step 3, which then observers an entry with the "present" flag set but random values in all other fields. This patch introduces a dedicated bitmap to track remapping entry allocation status instead of sharing the "present" flag with hardware, thus eliminate the race window. It also simplifies the implementation. Tested-and-reviewed-by: Yijing Wang Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/intel-iommu.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/intel-iommu.h') diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index d380c5e68008..de1e5e936420 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -288,6 +288,7 @@ struct q_inval { struct ir_table { struct irte *base; + unsigned long *bitmap; }; #endif -- cgit v1.2.3 From 694835dc227ad203886457aa447025d09b2f7523 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 6 Jan 2014 14:18:16 +0800 Subject: iommu/vt-d: mark internal functions as static Functions alloc_iommu() and parse_ioapics_under_ir() are only used internally, so mark them as static. [Joerg: Made detect_intel_iommu() non-static again for IA64] Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/intel-iommu.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/intel-iommu.h') diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index de1e5e936420..f2c4114b8665 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -348,7 +348,6 @@ static inline void __iommu_flush_cache( extern struct dmar_drhd_unit * dmar_find_matched_drhd_unit(struct pci_dev *dev); extern int dmar_find_matched_atsr_unit(struct pci_dev *dev); -extern int alloc_iommu(struct dmar_drhd_unit *drhd); extern void free_iommu(struct intel_iommu *iommu); extern int dmar_enable_qi(struct intel_iommu *iommu); extern void dmar_disable_qi(struct intel_iommu *iommu); -- cgit v1.2.3 From a868e6b7b661c3d3e7e681a16d0b205971987c99 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Mon, 6 Jan 2014 14:18:20 +0800 Subject: iommu/vt-d: keep shared resources when failed to initialize iommu devices Data structure drhd->iommu is shared between DMA remapping driver and interrupt remapping driver, so DMA remapping driver shouldn't release drhd->iommu when it failed to initialize IOMMU devices. Otherwise it may cause invalid memory access to the interrupt remapping driver. Sample stack dump: [ 13.315090] BUG: unable to handle kernel paging request at ffffc9000605a088 [ 13.323221] IP: [] qi_submit_sync+0x15c/0x400 [ 13.330107] PGD 82f81e067 PUD c2f81e067 PMD 82e846067 PTE 0 [ 13.336818] Oops: 0002 [#1] SMP [ 13.340757] Modules linked in: [ 13.344422] CPU: 0 PID: 4 Comm: kworker/0:0 Not tainted 3.13.0-rc1-gerry+ #7 [ 13.352474] Hardware name: Intel Corporation LH Pass ........../SVRBD-ROW_T, BIOS SE5C600.86B.99.99.x059.091020121352 09/10/2012 [ 13.365659] Workqueue: events work_for_cpu_fn [ 13.370774] task: ffff88042ddf00d0 ti: ffff88042ddee000 task.ti: ffff88042dde e000 [ 13.379389] RIP: 0010:[] [] qi_submit_sy nc+0x15c/0x400 [ 13.389055] RSP: 0000:ffff88042ddef940 EFLAGS: 00010002 [ 13.395151] RAX: 00000000000005e0 RBX: 0000000000000082 RCX: 0000000200000025 [ 13.403308] RDX: ffffc9000605a000 RSI: 0000000000000010 RDI: ffff88042ddb8610 [ 13.411446] RBP: ffff88042ddef9a0 R08: 00000000000005d0 R09: 0000000000000001 [ 13.419599] R10: 0000000000000000 R11: 000000000000005d R12: 000000000000005c [ 13.427742] R13: ffff88102d84d300 R14: 0000000000000174 R15: ffff88042ddb4800 [ 13.435877] FS: 0000000000000000(0000) GS:ffff88043de00000(0000) knlGS:00000 00000000000 [ 13.445168] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 13.451749] CR2: ffffc9000605a088 CR3: 0000000001a0b000 CR4: 00000000000407f0 [ 13.459895] Stack: [ 13.462297] ffff88042ddb85d0 000000000000005d ffff88042ddef9b0 0000000000000 5d0 [ 13.471147] 00000000000005c0 ffff88042ddb8000 000000000000005c 0000000000000 015 [ 13.480001] ffff88042ddb4800 0000000000000282 ffff88042ddefa40 ffff88042ddef ac0 [ 13.488855] Call Trace: [ 13.491771] [] modify_irte+0x9d/0xd0 [ 13.497778] [] intel_setup_ioapic_entry+0x10d/0x290 [ 13.505250] [] ? trace_hardirqs_on_caller+0x16/0x1e0 [ 13.512824] [] ? default_init_apic_ldr+0x60/0x60 [ 13.519998] [] setup_ioapic_remapped_entry+0x20/0x30 [ 13.527566] [] io_apic_setup_irq_pin+0x12a/0x2c0 [ 13.534742] [] ? acpi_pci_irq_find_prt_entry+0x2b9/0x2d8 [ 13.544102] [] io_apic_setup_irq_pin_once+0x85/0xa0 [ 13.551568] [] ? mp_find_ioapic_pin+0x8f/0xf0 [ 13.558434] [] io_apic_set_pci_routing+0x34/0x70 [ 13.565621] [] mp_register_gsi+0xaf/0x1c0 [ 13.572111] [] acpi_register_gsi_ioapic+0xe/0x10 [ 13.579286] [] acpi_register_gsi+0xf/0x20 [ 13.585779] [] acpi_pci_irq_enable+0x171/0x1e3 [ 13.592764] [] pcibios_enable_device+0x31/0x40 [ 13.599744] [] do_pci_enable_device+0x3b/0x60 [ 13.606633] [] pci_enable_device_flags+0xc8/0x120 [ 13.613887] [] pci_enable_device+0x13/0x20 [ 13.620484] [] pcie_port_device_register+0x1e/0x510 [ 13.627947] [] ? trace_hardirqs_on_caller+0x16/0x1e0 [ 13.635510] [] ? trace_hardirqs_on+0xd/0x10 [ 13.642189] [] pcie_portdrv_probe+0x58/0xc0 [ 13.648877] [] local_pci_probe+0x45/0xa0 [ 13.655266] [] work_for_cpu_fn+0x14/0x20 [ 13.661656] [] process_one_work+0x369/0x710 [ 13.668334] [] ? process_one_work+0x2f2/0x710 [ 13.675215] [] ? worker_thread+0x46/0x690 [ 13.681714] [] worker_thread+0x484/0x690 [ 13.688109] [] ? cancel_delayed_work_sync+0x20/0x20 [ 13.695576] [] kthread+0xf0/0x110 [ 13.701300] [] ? local_clock+0x3f/0x50 [ 13.707492] [] ? kthread_create_on_node+0x250/0x250 [ 13.714959] [] ret_from_fork+0x7c/0xb0 [ 13.721152] [] ? kthread_create_on_node+0x250/0x250 Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/intel-iommu.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux/intel-iommu.h') diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h index f2c4114b8665..2c4bed593b32 100644 --- a/include/linux/intel-iommu.h +++ b/include/linux/intel-iommu.h @@ -348,7 +348,6 @@ static inline void __iommu_flush_cache( extern struct dmar_drhd_unit * dmar_find_matched_drhd_unit(struct pci_dev *dev); extern int dmar_find_matched_atsr_unit(struct pci_dev *dev); -extern void free_iommu(struct intel_iommu *iommu); extern int dmar_enable_qi(struct intel_iommu *iommu); extern void dmar_disable_qi(struct intel_iommu *iommu); extern int dmar_reenable_qi(struct intel_iommu *iommu); -- cgit v1.2.3