From bb3a6b7845851d23cb826040b4c3c9c294e7cfb4 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:24 +0800 Subject: iommu/vt-d: Factor out dmar_alloc_dev_scope() for later reuse Factor out function dmar_alloc_dev_scope() from dmar_parse_dev_scope() for later reuse. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index eccb0c0c6cf6..1b08ce80bfbf 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -69,6 +69,7 @@ extern int dmar_table_init(void); extern int dmar_dev_scope_init(void); extern int dmar_parse_dev_scope(void *start, void *end, int *cnt, struct pci_dev ***devices, u16 segment); +extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt); extern void dmar_free_dev_scope(struct pci_dev ***devices, int *cnt); /* Intel IOMMU detection */ -- cgit v1.2.2 From b94e4117f8c4ffb591b1e462364d725e3a1c63c4 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:25 +0800 Subject: iommu/vt-d: Move private structures and variables into intel-iommu.c Move private structures and variables into intel-iommu.c, which will help to simplify locking policy for hotplug. Also delete redundant declarations. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 23 +---------------------- 1 file changed, 1 insertion(+), 22 deletions(-) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 1b08ce80bfbf..ea599d4ca9e0 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -139,28 +139,7 @@ extern int arch_setup_dmar_msi(unsigned int irq); #ifdef CONFIG_INTEL_IOMMU extern int iommu_detected, no_iommu; -extern struct list_head dmar_rmrr_units; -struct dmar_rmrr_unit { - struct list_head list; /* list of rmrr units */ - struct acpi_dmar_header *hdr; /* ACPI header */ - u64 base_address; /* reserved base address*/ - u64 end_address; /* reserved end address */ - struct pci_dev **devices; /* target devices */ - int devices_cnt; /* target device count */ -}; - -#define for_each_rmrr_units(rmrr) \ - list_for_each_entry(rmrr, &dmar_rmrr_units, list) - -struct dmar_atsr_unit { - struct list_head list; /* list of ATSR units */ - struct acpi_dmar_header *hdr; /* ACPI header */ - struct pci_dev **devices; /* target devices */ - int devices_cnt; /* target device count */ - u8 include_all:1; /* include all ports */ -}; - -int dmar_parse_rmrr_atsr_dev(void); +extern int dmar_parse_rmrr_atsr_dev(void); extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header); extern int dmar_parse_one_atsr(struct acpi_dmar_header *header); extern int intel_iommu_init(void); -- cgit v1.2.2 From b683b230a244c3b2b3f6f3292e59d4a63298528b Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:32 +0800 Subject: iommu/vt-d: Introduce macro for_each_dev_scope() to walk device scope entries Introduce for_each_dev_scope()/for_each_active_dev_scope() to walk {active} device scope entries. This will help following RCU lock related patches. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index ea599d4ca9e0..4b77fd8fde76 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -65,6 +65,12 @@ extern struct list_head dmar_drhd_units; list_for_each_entry(drhd, &dmar_drhd_units, list) \ if (i=drhd->iommu, 0) {} else +#define for_each_dev_scope(a, c, p, d) \ + for ((p) = 0; ((d) = (p) < (c) ? (a)[(p)] : NULL, (p) < (c)); (p)++) + +#define for_each_active_dev_scope(a, c, p, d) \ + for_each_dev_scope((a), (c), (p), (d)) if (!(d)) { continue; } else + extern int dmar_table_init(void); extern int dmar_dev_scope_init(void); extern int dmar_parse_dev_scope(void *start, void *end, int *cnt, -- cgit v1.2.2 From 3a5670e8ac932c10a3e50d9dc0ab1da4cc3041d7 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:33 +0800 Subject: iommu/vt-d: Introduce a rwsem to protect global data structures Introduce a global rwsem dmar_global_lock, which will be used to protect DMAR related global data structures from DMAR/PCI/memory device hotplug operations in process context. DMA and interrupt remapping related data structures are read most, and only change when memory/PCI/DMAR hotplug event happens. So a global rwsem solution is adopted for balance between simplicity and performance. For interrupt remapping driver, function intel_irq_remapping_supported(), dmar_table_init(), intel_enable_irq_remapping(), disable_irq_remapping(), reenable_irq_remapping() and enable_drhd_fault_handling() etc are called during booting, suspending and resuming with interrupt disabled, so no need to take the global lock. For interrupt remapping entry allocation, the locking model is: down_read(&dmar_global_lock); /* Find corresponding iommu */ iommu = map_hpet_to_ir(id); if (iommu) /* * Allocate remapping entry and mark entry busy, * the IOMMU won't be hot-removed until the * allocated entry has been released. */ index = alloc_irte(iommu, irq, 1); up_read(&dmar_global_lock); For DMA remmaping driver, we only uses the dmar_global_lock rwsem to protect functions which are only called in process context. For any function which may be called in interrupt context, we will use RCU to protect them in following patches. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 4b77fd8fde76..8f06a0135a84 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -25,6 +25,7 @@ #include #include #include +#include struct acpi_dmar_header; @@ -48,6 +49,7 @@ struct dmar_drhd_unit { struct intel_iommu *iommu; }; +extern struct rw_semaphore dmar_global_lock; extern struct list_head dmar_drhd_units; #define for_each_drhd_unit(drhd) \ -- cgit v1.2.2 From 0e242612d9cdb46e878ed1f126c78fe68492af00 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:34 +0800 Subject: iommu/vt-d: Use RCU to protect global resources in interrupt context Global DMA and interrupt remapping resources may be accessed in interrupt context, so use RCU instead of rwsem to protect them in such cases. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 8f06a0135a84..bedebab934b4 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -26,6 +26,7 @@ #include #include #include +#include struct acpi_dmar_header; @@ -41,7 +42,7 @@ struct dmar_drhd_unit { struct list_head list; /* list of drhd units */ struct acpi_dmar_header *hdr; /* ACPI header */ u64 reg_base_addr; /* register base address*/ - struct pci_dev **devices; /* target device array */ + struct pci_dev __rcu **devices;/* target device array */ int devices_cnt; /* target device count */ u16 segment; /* PCI domain */ u8 ignored:1; /* ignore drhd */ @@ -53,22 +54,31 @@ extern struct rw_semaphore dmar_global_lock; extern struct list_head dmar_drhd_units; #define for_each_drhd_unit(drhd) \ - list_for_each_entry(drhd, &dmar_drhd_units, list) + list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) #define for_each_active_drhd_unit(drhd) \ - list_for_each_entry(drhd, &dmar_drhd_units, list) \ + list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \ if (drhd->ignored) {} else #define for_each_active_iommu(i, drhd) \ - list_for_each_entry(drhd, &dmar_drhd_units, list) \ + list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \ if (i=drhd->iommu, drhd->ignored) {} else #define for_each_iommu(i, drhd) \ - list_for_each_entry(drhd, &dmar_drhd_units, list) \ + list_for_each_entry_rcu(drhd, &dmar_drhd_units, list) \ if (i=drhd->iommu, 0) {} else +static inline bool dmar_rcu_check(void) +{ + return rwsem_is_locked(&dmar_global_lock) || + system_state == SYSTEM_BOOTING; +} + +#define dmar_rcu_dereference(p) rcu_dereference_check((p), dmar_rcu_check()) + #define for_each_dev_scope(a, c, p, d) \ - for ((p) = 0; ((d) = (p) < (c) ? (a)[(p)] : NULL, (p) < (c)); (p)++) + for ((p) = 0; ((d) = (p) < (c) ? dmar_rcu_dereference((a)[(p)]) : \ + NULL, (p) < (c)); (p)++) #define for_each_active_dev_scope(a, c, p, d) \ for_each_dev_scope((a), (c), (p), (d)) if (!(d)) { continue; } else @@ -78,6 +88,7 @@ extern int dmar_dev_scope_init(void); extern int dmar_parse_dev_scope(void *start, void *end, int *cnt, struct pci_dev ***devices, u16 segment); extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt); +extern void dmar_free_dev_scope(struct pci_dev __rcu ***devices, int *cnt); extern void dmar_free_dev_scope(struct pci_dev ***devices, int *cnt); /* Intel IOMMU detection */ -- cgit v1.2.2 From 59ce0515cdaf3b7d47893d12f61e51d691863788 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:35 +0800 Subject: iommu/vt-d: Update DRHD/RMRR/ATSR device scope caches when PCI hotplug happens Current Intel DMAR/IOMMU driver assumes that all PCI devices associated with DMAR/RMRR/ATSR device scope arrays are created at boot time and won't change at runtime, so it caches pointers of associated PCI device object. That assumption may be wrong now due to: 1) introduction of PCI host bridge hotplug 2) PCI device hotplug through sysfs interfaces. Wang Yijing has tried to solve this issue by caching tupple instead of the PCI device object pointer, but that's still unreliable because PCI bus number may change in case of hotplug. Please refer to http://lkml.org/lkml/2013/11/5/64 Message from Yingjing's mail: after remove and rescan a pci device [ 611.857095] dmar: DRHD: handling fault status reg 2 [ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000 [ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857524] dmar: DRHD: handling fault status reg 102 [ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000 [ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.857936] dmar: DRHD: handling fault status reg 202 [ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000 [ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.858351] dmar: DRHD: handling fault status reg 302 [ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000 [ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear [ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready [ 611.860983] dmar: DRHD: handling fault status reg 402 [ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4 [ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope caches by hooking PCI bus notification. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index bedebab934b4..4e196430f1b2 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -50,6 +50,15 @@ struct dmar_drhd_unit { struct intel_iommu *iommu; }; +struct dmar_pci_notify_info { + struct pci_dev *dev; + unsigned long event; + int bus; + u16 seg; + u16 level; + struct acpi_dmar_pci_path path[]; +} __attribute__((packed)); + extern struct rw_semaphore dmar_global_lock; extern struct list_head dmar_drhd_units; @@ -89,12 +98,18 @@ extern int dmar_parse_dev_scope(void *start, void *end, int *cnt, struct pci_dev ***devices, u16 segment); extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt); extern void dmar_free_dev_scope(struct pci_dev __rcu ***devices, int *cnt); -extern void dmar_free_dev_scope(struct pci_dev ***devices, int *cnt); - +extern int dmar_insert_dev_scope(struct dmar_pci_notify_info *info, + void *start, void*end, u16 segment, + struct pci_dev __rcu **devices, + int devices_cnt); +extern int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, + u16 segment, struct pci_dev __rcu **devices, + int count); /* Intel IOMMU detection */ extern int detect_intel_iommu(void); extern int enable_drhd_fault_handling(void); #else +struct dmar_pci_notify_info; static inline int detect_intel_iommu(void) { return -ENODEV; @@ -161,6 +176,7 @@ extern int iommu_detected, no_iommu; extern int dmar_parse_rmrr_atsr_dev(void); extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header); extern int dmar_parse_one_atsr(struct acpi_dmar_header *header); +extern int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info); extern int intel_iommu_init(void); #else /* !CONFIG_INTEL_IOMMU: */ static inline int intel_iommu_init(void) { return -ENODEV; } @@ -176,6 +192,10 @@ static inline int dmar_parse_rmrr_atsr_dev(void) { return 0; } +static inline int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) +{ + return 0; +} #endif /* CONFIG_INTEL_IOMMU */ #endif /* __DMAR_H__ */ -- cgit v1.2.2 From 2e45528930388658603ea24d49cf52867b928d3e Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 19 Feb 2014 14:07:36 +0800 Subject: iommu/vt-d: Unify the way to process DMAR device scope array Now we have a PCI bus notification based mechanism to update DMAR device scope array, we could extend the mechanism to support boot time initialization too, which will help to unify and simplify the implementation. Signed-off-by: Jiang Liu Signed-off-by: Joerg Roedel --- include/linux/dmar.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 4e196430f1b2..0a92e4d978bc 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -173,7 +173,6 @@ extern int arch_setup_dmar_msi(unsigned int irq); #ifdef CONFIG_INTEL_IOMMU extern int iommu_detected, no_iommu; -extern int dmar_parse_rmrr_atsr_dev(void); extern int dmar_parse_one_rmrr(struct acpi_dmar_header *header); extern int dmar_parse_one_atsr(struct acpi_dmar_header *header); extern int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info); @@ -188,10 +187,6 @@ static inline int dmar_parse_one_atsr(struct acpi_dmar_header *header) { return 0; } -static inline int dmar_parse_rmrr_atsr_dev(void) -{ - return 0; -} static inline int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) { return 0; -- cgit v1.2.2 From 832bd858674023b2415c7585db3beba345ef807f Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Fri, 7 Mar 2014 15:08:36 +0000 Subject: iommu/vt-d: Change scope lists to struct device, bus, devfn It's not only for PCI devices any more, and the scope information for an ACPI device provides the bus and devfn so that has to be stored here too. It is the device pointer itself which needs to be protected with RCU, so the __rcu annotation follows it into the definition of struct dmar_dev_scope, since we're no longer just passing arrays of device pointers around. Signed-off-by: David Woodhouse --- include/linux/dmar.h | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'include/linux/dmar.h') diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 0a92e4d978bc..23c8db129560 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -36,13 +36,19 @@ struct acpi_dmar_header; struct intel_iommu; +struct dmar_dev_scope { + struct device __rcu *dev; + u8 bus; + u8 devfn; +}; + #ifdef CONFIG_DMAR_TABLE extern struct acpi_table_header *dmar_tbl; struct dmar_drhd_unit { struct list_head list; /* list of drhd units */ struct acpi_dmar_header *hdr; /* ACPI header */ u64 reg_base_addr; /* register base address*/ - struct pci_dev __rcu **devices;/* target device array */ + struct dmar_dev_scope *devices;/* target device array */ int devices_cnt; /* target device count */ u16 segment; /* PCI domain */ u8 ignored:1; /* ignore drhd */ @@ -86,7 +92,7 @@ static inline bool dmar_rcu_check(void) #define dmar_rcu_dereference(p) rcu_dereference_check((p), dmar_rcu_check()) #define for_each_dev_scope(a, c, p, d) \ - for ((p) = 0; ((d) = (p) < (c) ? dmar_rcu_dereference((a)[(p)]) : \ + for ((p) = 0; ((d) = (p) < (c) ? dmar_rcu_dereference((a)[(p)].dev) : \ NULL, (p) < (c)); (p)++) #define for_each_active_dev_scope(a, c, p, d) \ @@ -95,15 +101,15 @@ static inline bool dmar_rcu_check(void) extern int dmar_table_init(void); extern int dmar_dev_scope_init(void); extern int dmar_parse_dev_scope(void *start, void *end, int *cnt, - struct pci_dev ***devices, u16 segment); + struct dmar_dev_scope **devices, u16 segment); extern void *dmar_alloc_dev_scope(void *start, void *end, int *cnt); -extern void dmar_free_dev_scope(struct pci_dev __rcu ***devices, int *cnt); +extern void dmar_free_dev_scope(struct dmar_dev_scope **devices, int *cnt); extern int dmar_insert_dev_scope(struct dmar_pci_notify_info *info, void *start, void*end, u16 segment, - struct pci_dev __rcu **devices, + struct dmar_dev_scope *devices, int devices_cnt); extern int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, - u16 segment, struct pci_dev __rcu **devices, + u16 segment, struct dmar_dev_scope *devices, int count); /* Intel IOMMU detection */ extern int detect_intel_iommu(void); -- cgit v1.2.2