iommu/amd: Convert IOMMUv2 state_table into state_list
The state_table consumes 512kb of memory and is only sparsly
populated. Convert it into a list to save memory. There
should be no measurable performance impact.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Jay Cornwall <Jay.Cornwall@amd.com>
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 5db3675..569b6a0 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -56,6 +56,8 @@
};
struct device_state {
+ struct list_head list;
+ u16 devid;
atomic_t count;
struct pci_dev *pdev;
struct pasid_state **states;
@@ -81,7 +83,7 @@
u16 flags;
};
-static struct device_state **state_table;
+static LIST_HEAD(state_list);
static spinlock_t state_lock;
/* List and lock for all pasid_states */
@@ -113,7 +115,14 @@
static struct device_state *__get_device_state(u16 devid)
{
- return state_table[devid];
+ struct device_state *dev_state;
+
+ list_for_each_entry(dev_state, &state_list, list) {
+ if (dev_state->devid == devid)
+ return dev_state;
+ }
+
+ return NULL;
}
static struct device_state *get_device_state(u16 devid)
@@ -778,7 +787,8 @@
spin_lock_init(&dev_state->lock);
init_waitqueue_head(&dev_state->wq);
- dev_state->pdev = pdev;
+ dev_state->pdev = pdev;
+ dev_state->devid = devid;
tmp = pasids;
for (dev_state->pasid_levels = 0; (tmp - 1) & ~0x1ff; tmp >>= 9)
@@ -808,13 +818,13 @@
spin_lock_irqsave(&state_lock, flags);
- if (state_table[devid] != NULL) {
+ if (__get_device_state(devid) != NULL) {
spin_unlock_irqrestore(&state_lock, flags);
ret = -EBUSY;
goto out_free_domain;
}
- state_table[devid] = dev_state;
+ list_add_tail(&dev_state->list, &state_list);
spin_unlock_irqrestore(&state_lock, flags);
@@ -852,7 +862,7 @@
return;
}
- state_table[devid] = NULL;
+ list_del(&dev_state->list);
spin_unlock_irqrestore(&state_lock, flags);
@@ -927,7 +937,6 @@
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>\n");
@@ -943,16 +952,10 @@
spin_lock_init(&state_lock);
- state_table_size = MAX_DEVICES * sizeof(struct device_state *);
- state_table = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
- get_order(state_table_size));
- if (state_table == NULL)
- return -ENOMEM;
-
ret = -ENOMEM;
iommu_wq = create_workqueue("amd_iommu_v2");
if (iommu_wq == NULL)
- goto out_free;
+ goto out;
ret = -ENOMEM;
empty_page_table = (u64 *)get_zeroed_page(GFP_KERNEL);
@@ -967,16 +970,13 @@
out_destroy_wq:
destroy_workqueue(iommu_wq);
-out_free:
- free_pages((unsigned long)state_table, get_order(state_table_size));
-
+out:
return ret;
}
static void __exit amd_iommu_v2_exit(void)
{
struct device_state *dev_state;
- size_t state_table_size;
int i;
if (!amd_iommu_v2_supported())
@@ -1005,9 +1005,6 @@
destroy_workqueue(iommu_wq);
- 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);
}