From: Joerg Roedel Date: Thu, 24 Nov 2011 09:41:57 +0000 (+0100) Subject: iommu/amd: Add routines to bind/unbind a pasid X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=2d5503b624736abfe0e0bad281f9b8d8a705b930;p=mv-sheeva.git iommu/amd: Add routines to bind/unbind a pasid This patch adds routines to bind a specific process address-space to a given PASID. Signed-off-by: Joerg Roedel --- diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c index bfceed25c18..b5ee09ece65 100644 --- a/drivers/iommu/amd_iommu_v2.c +++ b/drivers/iommu/amd_iommu_v2.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -61,6 +62,10 @@ static spinlock_t state_lock; /* List and lock for all pasid_states */ static LIST_HEAD(pasid_state_list); +static DEFINE_SPINLOCK(ps_lock); + +static void free_pasid_states(struct device_state *dev_state); +static void unbind_pasid(struct device_state *dev_state, int pasid); static u16 device_id(struct pci_dev *pdev) { @@ -88,8 +93,16 @@ static struct device_state *get_device_state(u16 devid) static void free_device_state(struct device_state *dev_state) { + /* + * First detach device from domain - No more PRI requests will arrive + * from that device after it is unbound from the IOMMUv2 domain. + */ iommu_detach_device(dev_state->domain, &dev_state->pdev->dev); + + /* Everything is down now, free the IOMMUv2 domain */ iommu_domain_free(dev_state->domain); + + /* Finally get rid of the device-state */ kfree(dev_state); } @@ -99,6 +112,296 @@ static void put_device_state(struct device_state *dev_state) free_device_state(dev_state); } +static void link_pasid_state(struct pasid_state *pasid_state) +{ + spin_lock(&ps_lock); + list_add_tail(&pasid_state->list, &pasid_state_list); + spin_unlock(&ps_lock); +} + +static void __unlink_pasid_state(struct pasid_state *pasid_state) +{ + list_del(&pasid_state->list); +} + +static void unlink_pasid_state(struct pasid_state *pasid_state) +{ + spin_lock(&ps_lock); + __unlink_pasid_state(pasid_state); + spin_unlock(&ps_lock); +} + +/* Must be called under dev_state->lock */ +static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state, + int pasid, bool alloc) +{ + struct pasid_state **root, **ptr; + int level, index; + + level = dev_state->pasid_levels; + root = dev_state->states; + + while (true) { + + index = (pasid >> (9 * level)) & 0x1ff; + ptr = &root[index]; + + if (level == 0) + break; + + if (*ptr == NULL) { + if (!alloc) + return NULL; + + *ptr = (void *)get_zeroed_page(GFP_ATOMIC); + if (*ptr == NULL) + return NULL; + } + + root = (struct pasid_state **)*ptr; + level -= 1; + } + + return ptr; +} + +static int set_pasid_state(struct device_state *dev_state, + struct pasid_state *pasid_state, + int pasid) +{ + struct pasid_state **ptr; + unsigned long flags; + int ret; + + spin_lock_irqsave(&dev_state->lock, flags); + ptr = __get_pasid_state_ptr(dev_state, pasid, true); + + ret = -ENOMEM; + if (ptr == NULL) + goto out_unlock; + + ret = -ENOMEM; + if (*ptr != NULL) + goto out_unlock; + + *ptr = pasid_state; + + ret = 0; + +out_unlock: + spin_unlock_irqrestore(&dev_state->lock, flags); + + return ret; +} + +static void clear_pasid_state(struct device_state *dev_state, int pasid) +{ + struct pasid_state **ptr; + unsigned long flags; + + spin_lock_irqsave(&dev_state->lock, flags); + ptr = __get_pasid_state_ptr(dev_state, pasid, true); + + if (ptr == NULL) + goto out_unlock; + + *ptr = NULL; + +out_unlock: + spin_unlock_irqrestore(&dev_state->lock, flags); +} + +static struct pasid_state *get_pasid_state(struct device_state *dev_state, + int pasid) +{ + struct pasid_state **ptr, *ret = NULL; + unsigned long flags; + + spin_lock_irqsave(&dev_state->lock, flags); + ptr = __get_pasid_state_ptr(dev_state, pasid, false); + + if (ptr == NULL) + goto out_unlock; + + ret = *ptr; + if (ret) + atomic_inc(&ret->count); + +out_unlock: + spin_unlock_irqrestore(&dev_state->lock, flags); + + return ret; +} + +static void free_pasid_state(struct pasid_state *pasid_state) +{ + kfree(pasid_state); +} + +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); + } +} + +static void unbind_pasid(struct device_state *dev_state, int pasid) +{ + struct pasid_state *pasid_state; + + pasid_state = get_pasid_state(dev_state, pasid); + if (pasid_state == NULL) + 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(pasid_state); /* Reference taken in bind() function */ +} + +static void free_pasid_states_level1(struct pasid_state **tbl) +{ + int i; + + for (i = 0; i < 512; ++i) { + if (tbl[i] == NULL) + continue; + + free_page((unsigned long)tbl[i]); + } +} + +static void free_pasid_states_level2(struct pasid_state **tbl) +{ + struct pasid_state **ptr; + int i; + + for (i = 0; i < 512; ++i) { + if (tbl[i] == NULL) + continue; + + ptr = (struct pasid_state **)tbl[i]; + free_pasid_states_level1(ptr); + } +} + +static void free_pasid_states(struct device_state *dev_state) +{ + struct pasid_state *pasid_state; + int i; + + for (i = 0; i < dev_state->max_pasids; ++i) { + pasid_state = get_pasid_state(dev_state, i); + if (pasid_state == NULL) + continue; + + unbind_pasid(dev_state, i); + put_pasid_state(pasid_state); + } + + if (dev_state->pasid_levels == 2) + free_pasid_states_level2(dev_state->states); + else if (dev_state->pasid_levels == 1) + free_pasid_states_level1(dev_state->states); + else if (dev_state->pasid_levels != 0) + BUG(); + + free_page((unsigned long)dev_state->states); +} + +int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, + struct task_struct *task) +{ + struct pasid_state *pasid_state; + struct device_state *dev_state; + u16 devid; + int ret; + + might_sleep(); + + if (!amd_iommu_v2_supported()) + return -ENODEV; + + devid = device_id(pdev); + dev_state = get_device_state(devid); + + if (dev_state == NULL) + return -EINVAL; + + ret = -EINVAL; + if (pasid < 0 || pasid >= dev_state->max_pasids) + goto out; + + ret = -ENOMEM; + pasid_state = kzalloc(sizeof(*pasid_state), GFP_KERNEL); + if (pasid_state == NULL) + goto out; + + atomic_set(&pasid_state->count, 1); + pasid_state->task = task; + pasid_state->mm = get_task_mm(task); + pasid_state->device_state = dev_state; + pasid_state->pasid = pasid; + + if (pasid_state->mm == NULL) + goto out_free; + + ret = set_pasid_state(dev_state, pasid_state, pasid); + if (ret) + goto out_free; + + ret = amd_iommu_domain_set_gcr3(dev_state->domain, pasid, + __pa(pasid_state->mm->pgd)); + if (ret) + goto out_clear_state; + + link_pasid_state(pasid_state); + + return 0; + +out_clear_state: + clear_pasid_state(dev_state, pasid); + +out_free: + put_pasid_state(pasid_state); + +out: + put_device_state(dev_state); + + return ret; +} +EXPORT_SYMBOL(amd_iommu_bind_pasid); + +void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid) +{ + struct device_state *dev_state; + u16 devid; + + might_sleep(); + + if (!amd_iommu_v2_supported()) + return; + + devid = device_id(pdev); + dev_state = get_device_state(devid); + if (dev_state == NULL) + return; + + if (pasid < 0 || pasid >= dev_state->max_pasids) + goto out; + + unbind_pasid(dev_state, pasid); + +out: + put_device_state(dev_state); +} +EXPORT_SYMBOL(amd_iommu_unbind_pasid); + int amd_iommu_init_device(struct pci_dev *pdev, int pasids) { struct device_state *dev_state; @@ -199,6 +502,9 @@ void amd_iommu_free_device(struct pci_dev *pdev) spin_unlock_irqrestore(&state_lock, flags); + /* Get rid of any remaining pasid states */ + free_pasid_states(dev_state); + put_device_state(dev_state); } EXPORT_SYMBOL(amd_iommu_free_device); diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h index e8c7a2ec86b..23e21e15dfa 100644 --- a/include/linux/amd-iommu.h +++ b/include/linux/amd-iommu.h @@ -24,9 +24,13 @@ #ifdef CONFIG_AMD_IOMMU +struct task_struct; struct pci_dev; extern int amd_iommu_detect(void); +extern int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, + struct task_struct *task); +extern void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid); /** @@ -65,6 +69,28 @@ extern int amd_iommu_init_device(struct pci_dev *pdev, int pasids); */ extern void amd_iommu_free_device(struct pci_dev *pdev); +/** + * amd_iommu_bind_pasid() - Bind a given task to a PASID on a device + * @pdev: The PCI device to bind the task to + * @pasid: The PASID on the device the task should be bound to + * @task: the task to bind + * + * The function returns 0 on success or a negative value on error. + */ +extern int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, + struct task_struct *task); + +/** + * amd_iommu_unbind_pasid() - Unbind a PASID from its task on + * a device + * @pdev: The device of the PASID + * @pasid: The PASID to unbind + * + * When this function returns the device is no longer using the PASID + * and the PASID is no longer bound to its task. + */ +extern void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid); + #else static inline int amd_iommu_detect(void) { return -ENODEV; }