diff options
Diffstat (limited to 'drivers/iommu/iova.c')
-rw-r--r-- | drivers/iommu/iova.c | 95 |
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); } } |