diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/amd_iommu_v2.c | 204 |
1 files changed, 196 insertions, 8 deletions
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index b5ee09ece65..8804b224769 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -21,9 +21,11 @@ #include <linux/module.h> #include <linux/sched.h> #include <linux/iommu.h> +#include <linux/wait.h> #include <linux/pci.h> #include <linux/gfp.h> +#include "amd_iommu_types.h" #include "amd_iommu_proto.h" MODULE_LICENSE("GPL v2"); @@ -35,6 +37,7 @@ MODULE_AUTHOR("Joerg Roedel <joerg.roedel@amd.com>"); struct pri_queue { atomic_t inflight; bool finish; + int status; }; struct pasid_state { @@ -45,6 +48,8 @@ struct pasid_state { struct pri_queue pri[PRI_QUEUE_SIZE]; /* PRI tag states */ struct device_state *device_state; /* Link to our device_state */ int pasid; /* PASID index */ + spinlock_t lock; /* Protect pri_queues */ + wait_queue_head_t wq; /* To wait for count == 0 */ }; struct device_state { @@ -55,6 +60,20 @@ struct device_state { int pasid_levels; int max_pasids; spinlock_t lock; + wait_queue_head_t wq; +}; + +struct fault { + struct work_struct work; + struct device_state *dev_state; + struct pasid_state *state; + struct mm_struct *mm; + u64 address; + u16 devid; + u16 pasid; + u16 tag; + u16 finish; + u16 flags; }; struct device_state **state_table; @@ -64,6 +83,8 @@ static spinlock_t state_lock; static LIST_HEAD(pasid_state_list); static DEFINE_SPINLOCK(ps_lock); +static struct workqueue_struct *iommu_wq; + static void free_pasid_states(struct device_state *dev_state); static void unbind_pasid(struct device_state *dev_state, int pasid); @@ -109,9 +130,20 @@ static void free_device_state(struct device_state *dev_state) static void put_device_state(struct device_state *dev_state) { if (atomic_dec_and_test(&dev_state->count)) - free_device_state(dev_state); + wake_up(&dev_state->wq); } +static void put_device_state_wait(struct device_state *dev_state) +{ + DEFINE_WAIT(wait); + + prepare_to_wait(&dev_state->wq, &wait, TASK_UNINTERRUPTIBLE); + if (!atomic_dec_and_test(&dev_state->count)) + schedule(); + finish_wait(&dev_state->wq, &wait); + + free_device_state(dev_state); +} static void link_pasid_state(struct pasid_state *pasid_state) { spin_lock(&ps_lock); @@ -242,11 +274,26 @@ static void put_pasid_state(struct pasid_state *pasid_state) { if (atomic_dec_and_test(&pasid_state->count)) { put_device_state(pasid_state->device_state); - mmput(pasid_state->mm); - free_pasid_state(pasid_state); + wake_up(&pasid_state->wq); } } +static void put_pasid_state_wait(struct pasid_state *pasid_state) +{ + DEFINE_WAIT(wait); + + prepare_to_wait(&pasid_state->wq, &wait, TASK_UNINTERRUPTIBLE); + + if (atomic_dec_and_test(&pasid_state->count)) + put_device_state(pasid_state->device_state); + else + schedule(); + + finish_wait(&pasid_state->wq, &wait); + mmput(pasid_state->mm); + free_pasid_state(pasid_state); +} + static void unbind_pasid(struct device_state *dev_state, int pasid) { struct pasid_state *pasid_state; @@ -261,7 +308,7 @@ static void unbind_pasid(struct device_state *dev_state, int pasid) clear_pasid_state(dev_state, pasid); put_pasid_state(pasid_state); /* Reference taken in this function */ - put_pasid_state(pasid_state); /* Reference taken in bind() function */ + put_pasid_state_wait(pasid_state); /* Reference from bind() function */ } static void free_pasid_states_level1(struct pasid_state **tbl) @@ -300,8 +347,8 @@ static void free_pasid_states(struct device_state *dev_state) if (pasid_state == NULL) continue; - unbind_pasid(dev_state, i); put_pasid_state(pasid_state); + unbind_pasid(dev_state, i); } if (dev_state->pasid_levels == 2) @@ -314,6 +361,120 @@ static void free_pasid_states(struct device_state *dev_state) free_page((unsigned long)dev_state->states); } +static void set_pri_tag_status(struct pasid_state *pasid_state, + u16 tag, int status) +{ + unsigned long flags; + + spin_lock_irqsave(&pasid_state->lock, flags); + pasid_state->pri[tag].status = status; + spin_unlock_irqrestore(&pasid_state->lock, flags); +} + +static void finish_pri_tag(struct device_state *dev_state, + struct pasid_state *pasid_state, + u16 tag) +{ + unsigned long flags; + + spin_lock_irqsave(&pasid_state->lock, flags); + if (atomic_dec_and_test(&pasid_state->pri[tag].inflight) && + pasid_state->pri[tag].finish) { + amd_iommu_complete_ppr(dev_state->pdev, pasid_state->pasid, + pasid_state->pri[tag].status, tag); + pasid_state->pri[tag].finish = false; + pasid_state->pri[tag].status = PPR_SUCCESS; + } + spin_unlock_irqrestore(&pasid_state->lock, flags); +} + +static void do_fault(struct work_struct *work) +{ + struct fault *fault = container_of(work, struct fault, work); + int npages, write; + struct page *page; + + write = !!(fault->flags & PPR_FAULT_WRITE); + + npages = get_user_pages(fault->state->task, fault->state->mm, + fault->address, 1, write, 0, &page, NULL); + + if (npages == 1) + put_page(page); + else + set_pri_tag_status(fault->state, fault->tag, PPR_INVALID); + + finish_pri_tag(fault->dev_state, fault->state, fault->tag); + + put_pasid_state(fault->state); + + kfree(fault); +} + +static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data) +{ + struct amd_iommu_fault *iommu_fault; + struct pasid_state *pasid_state; + struct device_state *dev_state; + unsigned long flags; + struct fault *fault; + bool finish; + u16 tag; + int ret; + + iommu_fault = data; + tag = iommu_fault->tag & 0x1ff; + finish = (iommu_fault->tag >> 9) & 1; + + ret = NOTIFY_DONE; + dev_state = get_device_state(iommu_fault->device_id); + if (dev_state == NULL) + goto out; + + pasid_state = get_pasid_state(dev_state, iommu_fault->pasid); + if (pasid_state == NULL) { + /* We know the device but not the PASID -> send INVALID */ + amd_iommu_complete_ppr(dev_state->pdev, iommu_fault->pasid, + PPR_INVALID, tag); + goto out_drop_state; + } + + spin_lock_irqsave(&pasid_state->lock, flags); + atomic_inc(&pasid_state->pri[tag].inflight); + if (finish) + pasid_state->pri[tag].finish = true; + spin_unlock_irqrestore(&pasid_state->lock, flags); + + fault = kzalloc(sizeof(*fault), GFP_ATOMIC); + if (fault == NULL) { + /* We are OOM - send success and let the device re-fault */ + finish_pri_tag(dev_state, pasid_state, tag); + goto out_drop_state; + } + + fault->dev_state = dev_state; + fault->address = iommu_fault->address; + fault->state = pasid_state; + fault->tag = tag; + fault->finish = finish; + fault->flags = iommu_fault->flags; + INIT_WORK(&fault->work, do_fault); + + queue_work(iommu_wq, &fault->work); + + ret = NOTIFY_OK; + +out_drop_state: + put_device_state(dev_state); + +out: + return ret; +} + +static struct notifier_block ppr_nb = { + .notifier_call = ppr_notifier, +}; + int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, struct task_struct *task) { @@ -343,6 +504,7 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, goto out; atomic_set(&pasid_state->count, 1); + init_waitqueue_head(&pasid_state->wq); pasid_state->task = task; pasid_state->mm = get_task_mm(task); pasid_state->device_state = dev_state; @@ -368,7 +530,7 @@ out_clear_state: clear_pasid_state(dev_state, pasid); out_free: - put_pasid_state(pasid_state); + free_pasid_state(pasid_state); out: put_device_state(dev_state); @@ -424,6 +586,7 @@ int amd_iommu_init_device(struct pci_dev *pdev, int pasids) return -ENOMEM; spin_lock_init(&dev_state->lock); + init_waitqueue_head(&dev_state->wq); dev_state->pdev = pdev; tmp = pasids; @@ -505,13 +668,14 @@ void amd_iommu_free_device(struct pci_dev *pdev) /* Get rid of any remaining pasid states */ free_pasid_states(dev_state); - put_device_state(dev_state); + put_device_state_wait(dev_state); } EXPORT_SYMBOL(amd_iommu_free_device); static int __init amd_iommu_v2_init(void) { size_t state_table_size; + int ret; pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>"); @@ -523,7 +687,21 @@ static int __init amd_iommu_v2_init(void) if (state_table == NULL) return -ENOMEM; + ret = -ENOMEM; + iommu_wq = create_workqueue("amd_iommu_v2"); + if (iommu_wq == NULL) { + ret = -ENOMEM; + goto out_free; + } + + amd_iommu_register_ppr_notifier(&ppr_nb); + return 0; + +out_free: + free_pages((unsigned long)state_table, get_order(state_table_size)); + + return ret; } static void __exit amd_iommu_v2_exit(void) @@ -532,6 +710,14 @@ static void __exit amd_iommu_v2_exit(void) size_t state_table_size; int i; + amd_iommu_unregister_ppr_notifier(&ppr_nb); + + flush_workqueue(iommu_wq); + + /* + * The loop below might call flush_workqueue(), so call + * destroy_workqueue() after it + */ for (i = 0; i < MAX_DEVICES; ++i) { dev_state = get_device_state(i); @@ -540,10 +726,12 @@ static void __exit amd_iommu_v2_exit(void) WARN_ON_ONCE(1); - amd_iommu_free_device(dev_state->pdev); put_device_state(dev_state); + amd_iommu_free_device(dev_state->pdev); } + destroy_workqueue(iommu_wq); + state_table_size = MAX_DEVICES * sizeof(struct device_state *); free_pages((unsigned long)state_table, get_order(state_table_size)); } |