diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/iommu/amd_iommu_v2.c | 186 |
2 files changed, 178 insertions, 11 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index e608a36bb0b..6bea6962f8e 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -62,7 +62,8 @@ config AMD_IOMMU_STATS config AMD_IOMMU_V2 tristate "AMD IOMMU Version 2 driver (EXPERIMENTAL)" - depends on AMD_IOMMU && EXPERIMENTAL + depends on AMD_IOMMU && PROFILING && EXPERIMENTAL + select MMU_NOTIFIER ---help--- This option enables support for the AMD IOMMUv2 features of the IOMMU hardware. Select this option if you want to use devices that support diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index 8804b224769..abdb8396f89 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -16,8 +16,10 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/mmu_notifier.h> #include <linux/amd-iommu.h> #include <linux/mm_types.h> +#include <linux/profile.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/iommu.h> @@ -45,6 +47,7 @@ struct pasid_state { atomic_t count; /* Reference count */ struct task_struct *task; /* Task bound to this PASID */ struct mm_struct *mm; /* mm_struct for the faults */ + struct mmu_notifier mn; /* mmu_otifier handle */ struct pri_queue pri[PRI_QUEUE_SIZE]; /* PRI tag states */ struct device_state *device_state; /* Link to our device_state */ int pasid; /* PASID index */ @@ -85,8 +88,16 @@ static DEFINE_SPINLOCK(ps_lock); static struct workqueue_struct *iommu_wq; +/* + * Empty page table - Used between + * mmu_notifier_invalidate_range_start and + * mmu_notifier_invalidate_range_end + */ +static u64 *empty_page_table; + static void free_pasid_states(struct device_state *dev_state); static void unbind_pasid(struct device_state *dev_state, int pasid); +static int task_exit(struct notifier_block *nb, unsigned long e, void *data); static u16 device_id(struct pci_dev *pdev) { @@ -144,6 +155,11 @@ static void put_device_state_wait(struct device_state *dev_state) free_device_state(dev_state); } + +static struct notifier_block profile_nb = { + .notifier_call = task_exit, +}; + static void link_pasid_state(struct pasid_state *pasid_state) { spin_lock(&ps_lock); @@ -294,6 +310,23 @@ static void put_pasid_state_wait(struct pasid_state *pasid_state) free_pasid_state(pasid_state); } +static void __unbind_pasid(struct pasid_state *pasid_state) +{ + struct iommu_domain *domain; + + domain = pasid_state->device_state->domain; + + amd_iommu_domain_clear_gcr3(domain, pasid_state->pasid); + clear_pasid_state(pasid_state->device_state, pasid_state->pasid); + + /* Make sure no more pending faults are in the queue */ + flush_workqueue(iommu_wq); + + mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm); + + put_pasid_state(pasid_state); /* Reference taken in bind() function */ +} + static void unbind_pasid(struct device_state *dev_state, int pasid) { struct pasid_state *pasid_state; @@ -303,12 +336,8 @@ static void unbind_pasid(struct device_state *dev_state, int pasid) return; unlink_pasid_state(pasid_state); - - amd_iommu_domain_clear_gcr3(dev_state->domain, pasid); - clear_pasid_state(dev_state, pasid); - - put_pasid_state(pasid_state); /* Reference taken in this function */ - put_pasid_state_wait(pasid_state); /* Reference from bind() function */ + __unbind_pasid(pasid_state); + put_pasid_state_wait(pasid_state); /* Reference taken in this function */ } static void free_pasid_states_level1(struct pasid_state **tbl) @@ -361,6 +390,83 @@ static void free_pasid_states(struct device_state *dev_state) free_page((unsigned long)dev_state->states); } +static struct pasid_state *mn_to_state(struct mmu_notifier *mn) +{ + return container_of(mn, struct pasid_state, mn); +} + +static void __mn_flush_page(struct mmu_notifier *mn, + unsigned long address) +{ + struct pasid_state *pasid_state; + struct device_state *dev_state; + + pasid_state = mn_to_state(mn); + dev_state = pasid_state->device_state; + + amd_iommu_flush_page(dev_state->domain, pasid_state->pasid, address); +} + +static int mn_clear_flush_young(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address) +{ + __mn_flush_page(mn, address); + + return 0; +} + +static void mn_change_pte(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address, + pte_t pte) +{ + __mn_flush_page(mn, address); +} + +static void mn_invalidate_page(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address) +{ + __mn_flush_page(mn, address); +} + +static void mn_invalidate_range_start(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, unsigned long end) +{ + struct pasid_state *pasid_state; + struct device_state *dev_state; + + pasid_state = mn_to_state(mn); + dev_state = pasid_state->device_state; + + amd_iommu_domain_set_gcr3(dev_state->domain, pasid_state->pasid, + __pa(empty_page_table)); +} + +static void mn_invalidate_range_end(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, unsigned long end) +{ + struct pasid_state *pasid_state; + struct device_state *dev_state; + + pasid_state = mn_to_state(mn); + dev_state = pasid_state->device_state; + + amd_iommu_domain_set_gcr3(dev_state->domain, pasid_state->pasid, + __pa(pasid_state->mm->pgd)); +} + +static struct mmu_notifier_ops iommu_mn = { + .clear_flush_young = mn_clear_flush_young, + .change_pte = mn_change_pte, + .invalidate_page = mn_invalidate_page, + .invalidate_range_start = mn_invalidate_range_start, + .invalidate_range_end = mn_invalidate_range_end, +}; + static void set_pri_tag_status(struct pasid_state *pasid_state, u16 tag, int status) { @@ -475,6 +581,50 @@ static struct notifier_block ppr_nb = { .notifier_call = ppr_notifier, }; +static int task_exit(struct notifier_block *nb, unsigned long e, void *data) +{ + struct pasid_state *pasid_state; + struct task_struct *task; + + task = data; + + /* + * Using this notifier is a hack - but there is no other choice + * at the moment. What I really want is a sleeping notifier that + * is called when an MM goes down. But such a notifier doesn't + * exist yet. The notifier needs to sleep because it has to make + * sure that the device does not use the PASID and the address + * space anymore before it is destroyed. This includes waiting + * for pending PRI requests to pass the workqueue. The + * MMU-Notifiers would be a good fit, but they use RCU and so + * they are not allowed to sleep. Lets see how we can solve this + * in a more intelligent way in the future. + */ +again: + spin_lock(&ps_lock); + list_for_each_entry(pasid_state, &pasid_state_list, list) { + struct device_state *dev_state; + int pasid; + + if (pasid_state->task != task) + continue; + + /* Drop Lock and unbind */ + spin_unlock(&ps_lock); + + dev_state = pasid_state->device_state; + pasid = pasid_state->pasid; + + unbind_pasid(dev_state, pasid); + + /* Task may be in the list multiple times */ + goto again; + } + spin_unlock(&ps_lock); + + return NOTIFY_OK; +} + int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, struct task_struct *task) { @@ -509,13 +659,16 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, pasid_state->mm = get_task_mm(task); pasid_state->device_state = dev_state; pasid_state->pasid = pasid; + pasid_state->mn.ops = &iommu_mn; if (pasid_state->mm == NULL) goto out_free; + mmu_notifier_register(&pasid_state->mn, pasid_state->mm); + ret = set_pasid_state(dev_state, pasid_state, pasid); if (ret) - goto out_free; + goto out_unregister; ret = amd_iommu_domain_set_gcr3(dev_state->domain, pasid, __pa(pasid_state->mm->pgd)); @@ -529,6 +682,9 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, out_clear_state: clear_pasid_state(dev_state, pasid); +out_unregister: + mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm); + out_free: free_pasid_state(pasid_state); @@ -689,15 +845,22 @@ static int __init amd_iommu_v2_init(void) ret = -ENOMEM; iommu_wq = create_workqueue("amd_iommu_v2"); - if (iommu_wq == NULL) { - ret = -ENOMEM; + if (iommu_wq == NULL) goto out_free; - } + + ret = -ENOMEM; + empty_page_table = (u64 *)get_zeroed_page(GFP_KERNEL); + if (empty_page_table == NULL) + goto out_destroy_wq; amd_iommu_register_ppr_notifier(&ppr_nb); + profile_event_register(PROFILE_TASK_EXIT, &profile_nb); return 0; +out_destroy_wq: + destroy_workqueue(iommu_wq); + out_free: free_pages((unsigned long)state_table, get_order(state_table_size)); @@ -710,6 +873,7 @@ static void __exit amd_iommu_v2_exit(void) size_t state_table_size; int i; + profile_event_unregister(PROFILE_TASK_EXIT, &profile_nb); amd_iommu_unregister_ppr_notifier(&ppr_nb); flush_workqueue(iommu_wq); @@ -734,6 +898,8 @@ static void __exit amd_iommu_v2_exit(void) state_table_size = MAX_DEVICES * sizeof(struct device_state *); free_pages((unsigned long)state_table, get_order(state_table_size)); + + free_page((unsigned long)empty_page_table); } module_init(amd_iommu_v2_init); |