iommu/amd: Implement IO page-fault handler (028eeacc) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/iommu/amd_iommu_v2.c

+196 −8

Original line number	Original line	Diff line number	Diff line
	@@ -21,9 +21,11 @@
	#include <linux/module.h>		#include <linux/module.h>
	#include <linux/sched.h>		#include <linux/sched.h>
	#include <linux/iommu.h>		#include <linux/iommu.h>
			#include <linux/wait.h>
	#include <linux/pci.h>		#include <linux/pci.h>
	#include <linux/gfp.h>		#include <linux/gfp.h>

			#include "amd_iommu_types.h"
	#include "amd_iommu_proto.h"		#include "amd_iommu_proto.h"

	MODULE_LICENSE("GPL v2");		MODULE_LICENSE("GPL v2");
	@@ -35,6 +37,7 @@ MODULE_AUTHOR("Joerg Roedel <joerg.roedel@amd.com>");
	struct pri_queue {		struct pri_queue {
	atomic_t inflight;		atomic_t inflight;
	bool finish;		bool finish;
			int status;
	};		};

	struct pasid_state {		struct pasid_state {
	@@ -45,6 +48,8 @@ struct pasid_state {
	struct pri_queue pri[PRI_QUEUE_SIZE]; /* PRI tag states */		struct pri_queue pri[PRI_QUEUE_SIZE]; /* PRI tag states */
	struct device_state device_state; / Link to our device_state */		struct device_state device_state; / Link to our device_state */
	int pasid; /* PASID index */		int pasid; /* PASID index */
			spinlock_t lock; /* Protect pri_queues */
			wait_queue_head_t wq; /* To wait for count == 0 */
	};		};

	struct device_state {		struct device_state {
	@@ -55,6 +60,20 @@ struct device_state {
	int pasid_levels;		int pasid_levels;
	int max_pasids;		int max_pasids;
	spinlock_t lock;		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;		struct device_state **state_table;
	@@ -64,6 +83,8 @@ static spinlock_t state_lock;
	static LIST_HEAD(pasid_state_list);		static LIST_HEAD(pasid_state_list);
	static DEFINE_SPINLOCK(ps_lock);		static DEFINE_SPINLOCK(ps_lock);

			static struct workqueue_struct *iommu_wq;

	static void free_pasid_states(struct device_state *dev_state);		static void free_pasid_states(struct device_state *dev_state);
	static void unbind_pasid(struct device_state *dev_state, int pasid);		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)		static void put_device_state(struct device_state *dev_state)
	{		{
	if (atomic_dec_and_test(&dev_state->count))		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)		static void link_pasid_state(struct pasid_state *pasid_state)
	{		{
	spin_lock(&ps_lock);		spin_lock(&ps_lock);
	@@ -242,10 +274,25 @@ static void put_pasid_state(struct pasid_state *pasid_state)
	{		{
	if (atomic_dec_and_test(&pasid_state->count)) {		if (atomic_dec_and_test(&pasid_state->count)) {
	put_device_state(pasid_state->device_state);		put_device_state(pasid_state->device_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);		mmput(pasid_state->mm);
	free_pasid_state(pasid_state);		free_pasid_state(pasid_state);
	}		}
	}

	static void unbind_pasid(struct device_state *dev_state, int pasid)		static void unbind_pasid(struct device_state *dev_state, int pasid)
	{		{
	@@ -261,7 +308,7 @@ static void unbind_pasid(struct device_state *dev_state, int pasid)
	clear_pasid_state(dev_state, 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 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)		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)		if (pasid_state == NULL)
	continue;		continue;

	unbind_pasid(dev_state, i);
	put_pasid_state(pasid_state);		put_pasid_state(pasid_state);
			unbind_pasid(dev_state, i);
	}		}

	if (dev_state->pasid_levels == 2)		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);		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,		int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
	struct task_struct *task)		struct task_struct *task)
	{		{
	@@ -343,6 +504,7 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
	goto out;		goto out;

	atomic_set(&pasid_state->count, 1);		atomic_set(&pasid_state->count, 1);
			init_waitqueue_head(&pasid_state->wq);
	pasid_state->task = task;		pasid_state->task = task;
	pasid_state->mm = get_task_mm(task);		pasid_state->mm = get_task_mm(task);
	pasid_state->device_state = dev_state;		pasid_state->device_state = dev_state;
	@@ -368,7 +530,7 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
	clear_pasid_state(dev_state, pasid);		clear_pasid_state(dev_state, pasid);

	out_free:		out_free:
	put_pasid_state(pasid_state);		free_pasid_state(pasid_state);

	out:		out:
	put_device_state(dev_state);		put_device_state(dev_state);
	@@ -424,6 +586,7 @@ int amd_iommu_init_device(struct pci_dev *pdev, int pasids)
	return -ENOMEM;		return -ENOMEM;

	spin_lock_init(&dev_state->lock);		spin_lock_init(&dev_state->lock);
			init_waitqueue_head(&dev_state->wq);
	dev_state->pdev = pdev;		dev_state->pdev = pdev;

	tmp = pasids;		tmp = pasids;
	@@ -505,13 +668,14 @@ void amd_iommu_free_device(struct pci_dev *pdev)
	/* Get rid of any remaining pasid states */		/* Get rid of any remaining pasid states */
	free_pasid_states(dev_state);		free_pasid_states(dev_state);

	put_device_state(dev_state);		put_device_state_wait(dev_state);
	}		}
	EXPORT_SYMBOL(amd_iommu_free_device);		EXPORT_SYMBOL(amd_iommu_free_device);

	static int __init amd_iommu_v2_init(void)		static int __init amd_iommu_v2_init(void)
	{		{
	size_t state_table_size;		size_t state_table_size;
			int ret;

	pr_info("AMD IOMMUv2 driver by Joerg Roedel <joerg.roedel@amd.com>");		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)		if (state_table == NULL)
	return -ENOMEM;		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;		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)		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;		size_t state_table_size;
	int i;		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) {		for (i = 0; i < MAX_DEVICES; ++i) {
	dev_state = get_device_state(i);		dev_state = get_device_state(i);

	@@ -540,10 +726,12 @@ static void __exit amd_iommu_v2_exit(void)

	WARN_ON_ONCE(1);		WARN_ON_ONCE(1);

	amd_iommu_free_device(dev_state->pdev);
	put_device_state(dev_state);		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 *);		state_table_size = MAX_DEVICES * sizeof(struct device_state *);
	free_pages((unsigned long)state_table, get_order(state_table_size));		free_pages((unsigned long)state_table, get_order(state_table_size));
	}		}