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path: root/drivers/iommu/iova.c
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Diffstat (limited to 'drivers/iommu/iova.c')
-rw-r--r--drivers/iommu/iova.c95
1 files changed, 65 insertions, 30 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 10b964600948..d30e453d0fb4 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -11,6 +11,7 @@
#include <linux/smp.h>
#include <linux/bitops.h>
#include <linux/cpu.h>
+#include <linux/workqueue.h>
/* The anchor node sits above the top of the usable address space */
#define IOVA_ANCHOR ~0UL
@@ -622,15 +623,21 @@ EXPORT_SYMBOL_GPL(reserve_iova);
/*
* As kmalloc's buffer size is fixed to power of 2, 127 is chosen to
* assure size of 'iova_magazine' to be 1024 bytes, so that no memory
- * will be wasted.
+ * will be wasted. Since only full magazines are inserted into the depot,
+ * we don't need to waste PFN capacity on a separate list head either.
*/
#define IOVA_MAG_SIZE 127
-#define MAX_GLOBAL_MAGS 32 /* magazines per bin */
+
+#define IOVA_DEPOT_DELAY msecs_to_jiffies(100)
struct iova_magazine {
- unsigned long size;
+ union {
+ unsigned long size;
+ struct iova_magazine *next;
+ };
unsigned long pfns[IOVA_MAG_SIZE];
};
+static_assert(!(sizeof(struct iova_magazine) & (sizeof(struct iova_magazine) - 1)));
struct iova_cpu_rcache {
spinlock_t lock;
@@ -640,9 +647,11 @@ struct iova_cpu_rcache {
struct iova_rcache {
spinlock_t lock;
- unsigned long depot_size;
- struct iova_magazine *depot[MAX_GLOBAL_MAGS];
+ unsigned int depot_size;
+ struct iova_magazine *depot;
struct iova_cpu_rcache __percpu *cpu_rcaches;
+ struct iova_domain *iovad;
+ struct delayed_work work;
};
static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
@@ -717,6 +726,41 @@ static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
mag->pfns[mag->size++] = pfn;
}
+static struct iova_magazine *iova_depot_pop(struct iova_rcache *rcache)
+{
+ struct iova_magazine *mag = rcache->depot;
+
+ rcache->depot = mag->next;
+ mag->size = IOVA_MAG_SIZE;
+ rcache->depot_size--;
+ return mag;
+}
+
+static void iova_depot_push(struct iova_rcache *rcache, struct iova_magazine *mag)
+{
+ mag->next = rcache->depot;
+ rcache->depot = mag;
+ rcache->depot_size++;
+}
+
+static void iova_depot_work_func(struct work_struct *work)
+{
+ struct iova_rcache *rcache = container_of(work, typeof(*rcache), work.work);
+ struct iova_magazine *mag = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rcache->lock, flags);
+ if (rcache->depot_size > num_online_cpus())
+ mag = iova_depot_pop(rcache);
+ spin_unlock_irqrestore(&rcache->lock, flags);
+
+ if (mag) {
+ iova_magazine_free_pfns(mag, rcache->iovad);
+ iova_magazine_free(mag);
+ schedule_delayed_work(&rcache->work, IOVA_DEPOT_DELAY);
+ }
+}
+
int iova_domain_init_rcaches(struct iova_domain *iovad)
{
unsigned int cpu;
@@ -734,7 +778,8 @@ int iova_domain_init_rcaches(struct iova_domain *iovad)
rcache = &iovad->rcaches[i];
spin_lock_init(&rcache->lock);
- rcache->depot_size = 0;
+ rcache->iovad = iovad;
+ INIT_DELAYED_WORK(&rcache->work, iova_depot_work_func);
rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache),
cache_line_size());
if (!rcache->cpu_rcaches) {
@@ -776,7 +821,6 @@ static bool __iova_rcache_insert(struct iova_domain *iovad,
struct iova_rcache *rcache,
unsigned long iova_pfn)
{
- struct iova_magazine *mag_to_free = NULL;
struct iova_cpu_rcache *cpu_rcache;
bool can_insert = false;
unsigned long flags;
@@ -794,13 +838,9 @@ static bool __iova_rcache_insert(struct iova_domain *iovad,
if (new_mag) {
spin_lock(&rcache->lock);
- if (rcache->depot_size < MAX_GLOBAL_MAGS) {
- rcache->depot[rcache->depot_size++] =
- cpu_rcache->loaded;
- } else {
- mag_to_free = cpu_rcache->loaded;
- }
+ iova_depot_push(rcache, cpu_rcache->loaded);
spin_unlock(&rcache->lock);
+ schedule_delayed_work(&rcache->work, IOVA_DEPOT_DELAY);
cpu_rcache->loaded = new_mag;
can_insert = true;
@@ -812,11 +852,6 @@ static bool __iova_rcache_insert(struct iova_domain *iovad,
spin_unlock_irqrestore(&cpu_rcache->lock, flags);
- if (mag_to_free) {
- iova_magazine_free_pfns(mag_to_free, iovad);
- iova_magazine_free(mag_to_free);
- }
-
return can_insert;
}
@@ -854,9 +889,9 @@ static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
has_pfn = true;
} else {
spin_lock(&rcache->lock);
- if (rcache->depot_size > 0) {
+ if (rcache->depot) {
iova_magazine_free(cpu_rcache->loaded);
- cpu_rcache->loaded = rcache->depot[--rcache->depot_size];
+ cpu_rcache->loaded = iova_depot_pop(rcache);
has_pfn = true;
}
spin_unlock(&rcache->lock);
@@ -895,9 +930,8 @@ static void free_iova_rcaches(struct iova_domain *iovad)
struct iova_rcache *rcache;
struct iova_cpu_rcache *cpu_rcache;
unsigned int cpu;
- int i, j;
- for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+ for (int i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
rcache = &iovad->rcaches[i];
if (!rcache->cpu_rcaches)
break;
@@ -907,8 +941,9 @@ static void free_iova_rcaches(struct iova_domain *iovad)
iova_magazine_free(cpu_rcache->prev);
}
free_percpu(rcache->cpu_rcaches);
- for (j = 0; j < rcache->depot_size; ++j)
- iova_magazine_free(rcache->depot[j]);
+ cancel_delayed_work_sync(&rcache->work);
+ while (rcache->depot)
+ iova_magazine_free(iova_depot_pop(rcache));
}
kfree(iovad->rcaches);
@@ -942,16 +977,16 @@ static void free_global_cached_iovas(struct iova_domain *iovad)
{
struct iova_rcache *rcache;
unsigned long flags;
- int i, j;
- for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
+ for (int i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
rcache = &iovad->rcaches[i];
spin_lock_irqsave(&rcache->lock, flags);
- for (j = 0; j < rcache->depot_size; ++j) {
- iova_magazine_free_pfns(rcache->depot[j], iovad);
- iova_magazine_free(rcache->depot[j]);
+ while (rcache->depot) {
+ struct iova_magazine *mag = iova_depot_pop(rcache);
+
+ iova_magazine_free_pfns(mag, iovad);
+ iova_magazine_free(mag);
}
- rcache->depot_size = 0;
spin_unlock_irqrestore(&rcache->lock, flags);
}
}