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iommu/amd: Implement IO page-fault handler
Register the notifier for PPR faults and handle them as necessary. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Joerg Roedel
parent
2d5503b624
commit
028eeacc41
@ -21,9 +21,11 @@
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/iommu.h>
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#include <linux/wait.h>
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#include <linux/pci.h>
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#include <linux/gfp.h>
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#include "amd_iommu_types.h"
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#include "amd_iommu_proto.h"
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MODULE_LICENSE("GPL v2");
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@ -35,6 +37,7 @@ MODULE_AUTHOR("Joerg Roedel <joerg.roedel@amd.com>");
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struct pri_queue {
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atomic_t inflight;
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bool finish;
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int status;
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};
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struct pasid_state {
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@ -45,6 +48,8 @@ struct pasid_state {
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struct pri_queue pri[PRI_QUEUE_SIZE]; /* PRI tag states */
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struct device_state *device_state; /* Link to our device_state */
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int pasid; /* PASID index */
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spinlock_t lock; /* Protect pri_queues */
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wait_queue_head_t wq; /* To wait for count == 0 */
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};
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struct device_state {
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@ -55,6 +60,20 @@ struct device_state {
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int pasid_levels;
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int max_pasids;
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spinlock_t lock;
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wait_queue_head_t wq;
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};
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struct fault {
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struct work_struct work;
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struct device_state *dev_state;
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struct pasid_state *state;
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struct mm_struct *mm;
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u64 address;
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u16 devid;
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u16 pasid;
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u16 tag;
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u16 finish;
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u16 flags;
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};
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struct device_state **state_table;
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@ -64,6 +83,8 @@ static spinlock_t state_lock;
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static LIST_HEAD(pasid_state_list);
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static DEFINE_SPINLOCK(ps_lock);
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static struct workqueue_struct *iommu_wq;
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static void free_pasid_states(struct device_state *dev_state);
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static void unbind_pasid(struct device_state *dev_state, int pasid);
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@ -109,9 +130,20 @@ static void free_device_state(struct device_state *dev_state)
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static void put_device_state(struct device_state *dev_state)
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{
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if (atomic_dec_and_test(&dev_state->count))
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free_device_state(dev_state);
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wake_up(&dev_state->wq);
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}
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static void put_device_state_wait(struct device_state *dev_state)
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{
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DEFINE_WAIT(wait);
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prepare_to_wait(&dev_state->wq, &wait, TASK_UNINTERRUPTIBLE);
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if (!atomic_dec_and_test(&dev_state->count))
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schedule();
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finish_wait(&dev_state->wq, &wait);
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free_device_state(dev_state);
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}
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static void link_pasid_state(struct pasid_state *pasid_state)
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{
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spin_lock(&ps_lock);
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@ -242,11 +274,26 @@ static void put_pasid_state(struct pasid_state *pasid_state)
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{
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if (atomic_dec_and_test(&pasid_state->count)) {
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put_device_state(pasid_state->device_state);
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mmput(pasid_state->mm);
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free_pasid_state(pasid_state);
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wake_up(&pasid_state->wq);
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}
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}
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static void put_pasid_state_wait(struct pasid_state *pasid_state)
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{
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DEFINE_WAIT(wait);
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prepare_to_wait(&pasid_state->wq, &wait, TASK_UNINTERRUPTIBLE);
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if (atomic_dec_and_test(&pasid_state->count))
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put_device_state(pasid_state->device_state);
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else
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schedule();
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finish_wait(&pasid_state->wq, &wait);
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mmput(pasid_state->mm);
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free_pasid_state(pasid_state);
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}
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static void unbind_pasid(struct device_state *dev_state, int pasid)
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{
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struct pasid_state *pasid_state;
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@ -261,7 +308,7 @@ static void unbind_pasid(struct device_state *dev_state, int pasid)
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clear_pasid_state(dev_state, pasid);
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put_pasid_state(pasid_state); /* Reference taken in this function */
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put_pasid_state(pasid_state); /* Reference taken in bind() function */
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put_pasid_state_wait(pasid_state); /* Reference from bind() function */
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}
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static void free_pasid_states_level1(struct pasid_state **tbl)
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@ -300,8 +347,8 @@ static void free_pasid_states(struct device_state *dev_state)
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if (pasid_state == NULL)
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continue;
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unbind_pasid(dev_state, i);
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put_pasid_state(pasid_state);
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unbind_pasid(dev_state, i);
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}
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if (dev_state->pasid_levels == 2)
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@ -314,6 +361,120 @@ static void free_pasid_states(struct device_state *dev_state)
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free_page((unsigned long)dev_state->states);
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}
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static void set_pri_tag_status(struct pasid_state *pasid_state,
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u16 tag, int status)
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{
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unsigned long flags;
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spin_lock_irqsave(&pasid_state->lock, flags);
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pasid_state->pri[tag].status = status;
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spin_unlock_irqrestore(&pasid_state->lock, flags);
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}
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static void finish_pri_tag(struct device_state *dev_state,
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struct pasid_state *pasid_state,
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u16 tag)
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{
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unsigned long flags;
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spin_lock_irqsave(&pasid_state->lock, flags);
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if (atomic_dec_and_test(&pasid_state->pri[tag].inflight) &&
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pasid_state->pri[tag].finish) {
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amd_iommu_complete_ppr(dev_state->pdev, pasid_state->pasid,
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pasid_state->pri[tag].status, tag);
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pasid_state->pri[tag].finish = false;
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pasid_state->pri[tag].status = PPR_SUCCESS;
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}
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spin_unlock_irqrestore(&pasid_state->lock, flags);
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}
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static void do_fault(struct work_struct *work)
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{
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struct fault *fault = container_of(work, struct fault, work);
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int npages, write;
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struct page *page;
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write = !!(fault->flags & PPR_FAULT_WRITE);
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npages = get_user_pages(fault->state->task, fault->state->mm,
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fault->address, 1, write, 0, &page, NULL);
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if (npages == 1)
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put_page(page);
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else
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set_pri_tag_status(fault->state, fault->tag, PPR_INVALID);
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finish_pri_tag(fault->dev_state, fault->state, fault->tag);
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put_pasid_state(fault->state);
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kfree(fault);
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}
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static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data)
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{
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struct amd_iommu_fault *iommu_fault;
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struct pasid_state *pasid_state;
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struct device_state *dev_state;
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unsigned long flags;
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struct fault *fault;
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bool finish;
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u16 tag;
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int ret;
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iommu_fault = data;
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tag = iommu_fault->tag & 0x1ff;
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finish = (iommu_fault->tag >> 9) & 1;
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ret = NOTIFY_DONE;
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dev_state = get_device_state(iommu_fault->device_id);
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if (dev_state == NULL)
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goto out;
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pasid_state = get_pasid_state(dev_state, iommu_fault->pasid);
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if (pasid_state == NULL) {
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/* We know the device but not the PASID -> send INVALID */
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amd_iommu_complete_ppr(dev_state->pdev, iommu_fault->pasid,
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PPR_INVALID, tag);
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goto out_drop_state;
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}
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spin_lock_irqsave(&pasid_state->lock, flags);
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atomic_inc(&pasid_state->pri[tag].inflight);
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if (finish)
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pasid_state->pri[tag].finish = true;
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spin_unlock_irqrestore(&pasid_state->lock, flags);
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fault = kzalloc(sizeof(*fault), GFP_ATOMIC);
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if (fault == NULL) {
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/* We are OOM - send success and let the device re-fault */
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finish_pri_tag(dev_state, pasid_state, tag);
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goto out_drop_state;
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}
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fault->dev_state = dev_state;
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fault->address = iommu_fault->address;
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fault->state = pasid_state;
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fault->tag = tag;
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fault->finish = finish;
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fault->flags = iommu_fault->flags;
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INIT_WORK(&fault->work, do_fault);
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queue_work(iommu_wq, &fault->work);
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ret = NOTIFY_OK;
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out_drop_state:
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put_device_state(dev_state);
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out:
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return ret;
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}
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static struct notifier_block ppr_nb = {
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.notifier_call = ppr_notifier,
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};
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int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
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struct task_struct *task)
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{
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@ -343,6 +504,7 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
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goto out;
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atomic_set(&pasid_state->count, 1);
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init_waitqueue_head(&pasid_state->wq);
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pasid_state->task = task;
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pasid_state->mm = get_task_mm(task);
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pasid_state->device_state = dev_state;
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@ -368,7 +530,7 @@ out_clear_state:
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clear_pasid_state(dev_state, pasid);
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out_free:
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put_pasid_state(pasid_state);
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free_pasid_state(pasid_state);
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out:
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put_device_state(dev_state);
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@ -424,6 +586,7 @@ int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
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return -ENOMEM;
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spin_lock_init(&dev_state->lock);
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init_waitqueue_head(&dev_state->wq);
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dev_state->pdev = pdev;
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tmp = pasids;
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@ -505,13 +668,14 @@ void amd_iommu_free_device(struct pci_dev *pdev)
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/* Get rid of any remaining pasid states */
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free_pasid_states(dev_state);
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put_device_state(dev_state);
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put_device_state_wait(dev_state);
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}
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EXPORT_SYMBOL(amd_iommu_free_device);
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static int __init amd_iommu_v2_init(void)
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{
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size_t state_table_size;
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int ret;
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pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>");
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@ -523,7 +687,21 @@ static int __init amd_iommu_v2_init(void)
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if (state_table == NULL)
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return -ENOMEM;
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ret = -ENOMEM;
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iommu_wq = create_workqueue("amd_iommu_v2");
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if (iommu_wq == NULL) {
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ret = -ENOMEM;
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goto out_free;
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}
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amd_iommu_register_ppr_notifier(&ppr_nb);
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return 0;
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out_free:
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free_pages((unsigned long)state_table, get_order(state_table_size));
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return ret;
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}
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static void __exit amd_iommu_v2_exit(void)
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@ -532,6 +710,14 @@ static void __exit amd_iommu_v2_exit(void)
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size_t state_table_size;
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int i;
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amd_iommu_unregister_ppr_notifier(&ppr_nb);
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flush_workqueue(iommu_wq);
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/*
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* The loop below might call flush_workqueue(), so call
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* destroy_workqueue() after it
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*/
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for (i = 0; i < MAX_DEVICES; ++i) {
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dev_state = get_device_state(i);
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@ -540,10 +726,12 @@ static void __exit amd_iommu_v2_exit(void)
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WARN_ON_ONCE(1);
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amd_iommu_free_device(dev_state->pdev);
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put_device_state(dev_state);
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amd_iommu_free_device(dev_state->pdev);
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}
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destroy_workqueue(iommu_wq);
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state_table_size = MAX_DEVICES * sizeof(struct device_state *);
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free_pages((unsigned long)state_table, get_order(state_table_size));
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}
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