[PATCH v2 04/11] iommu/iova: Squash entry_dtor abstraction

Robin Murphy
2021-12-10T17:55:16Z

All flush queues are driven by iommu-dma now, so there is no need to
abstract entry_dtor or its data any more. Squash the now-canonical
implementation directly into the IOVA code to get it out of the way.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

v2: No change

drivers/iommu/dma-iommu.c | 17 ++---------------
drivers/iommu/iova.c | 28 +++++++++++++++-------------
include/linux/iova.h | 26 +++-----------------------
3 files changed, 20 insertions(+), 51 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index b42e38a0dbe2..fa21b9141b71 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -64,18 +64,6 @@ static int __init iommu_dma_forcedac_setup(char *str)
}
early_param("iommu.forcedac", iommu_dma_forcedac_setup);

-static void iommu_dma_entry_dtor(unsigned long data)
-{
- struct page *freelist = (struct page *)data;
-
- while (freelist) {
- unsigned long p = (unsigned long)page_address(freelist);
-
- freelist = freelist->freelist;
- free_page(p);
- }
-}
-
static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
{
if (cookie->type == IOMMU_DMA_IOVA_COOKIE)
@@ -324,8 +312,7 @@ int iommu_dma_init_fq(struct iommu_domain *domain)
if (cookie->fq_domain)
return 0;

- ret = init_iova_flush_queue(&cookie->iovad, iommu_dma_flush_iotlb_all,
- iommu_dma_entry_dtor);
+ ret = init_iova_flush_queue(&cookie->iovad, iommu_dma_flush_iotlb_all);
if (ret) {
pr_warn("iova flush queue initialization failed\n");
return ret;
@@ -479,7 +466,7 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
else if (gather && gather->queued)
queue_iova(iovad, iova_pfn(iovad, iova),
size >> iova_shift(iovad),
- (unsigned long)gather->freelist);
+ gather->freelist);
else
free_iova_fast(iovad, iova_pfn(iovad, iova),
size >> iova_shift(iovad));
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 920fcc27c9a1..280dd0c7fe1b 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -91,11 +91,9 @@ static void free_iova_flush_queue(struct iova_domain *iovad)

iovad->fq = NULL;
iovad->flush_cb = NULL;
- iovad->entry_dtor = NULL;
}

-int init_iova_flush_queue(struct iova_domain *iovad,
- iova_flush_cb flush_cb, iova_entry_dtor entry_dtor)
+int init_iova_flush_queue(struct iova_domain *iovad, iova_flush_cb flush_cb)
{
struct iova_fq __percpu *queue;
int cpu;
@@ -108,7 +106,6 @@ int init_iova_flush_queue(struct iova_domain *iovad,
return -ENOMEM;

iovad->flush_cb = flush_cb;
- iovad->entry_dtor = entry_dtor;

for_each_possible_cpu(cpu) {
struct iova_fq *fq;
@@ -538,6 +535,16 @@ free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
}
EXPORT_SYMBOL_GPL(free_iova_fast);

+static void fq_entry_dtor(struct page *freelist)
+{
+ while (freelist) {
+ unsigned long p = (unsigned long)page_address(freelist);
+
+ freelist = freelist->freelist;
+ free_page(p);
+ }
+}
+
#define fq_ring_for_each(i, fq) \
for ((i) = (fq)->head; (i) != (fq)->tail; (i) = ((i) + 1) % IOVA_FQ_SIZE)

@@ -570,9 +577,7 @@ static void fq_ring_free(struct iova_domain *iovad, struct iova_fq *fq)
if (fq->entries[idx].counter >= counter)
break;

- if (iovad->entry_dtor)
- iovad->entry_dtor(fq->entries[idx].data);
-
+ fq_entry_dtor(fq->entries[idx].freelist);
free_iova_fast(iovad,
fq->entries[idx].iova_pfn,
fq->entries[idx].pages);
@@ -597,15 +602,12 @@ static void fq_destroy_all_entries(struct iova_domain *iovad)
* bother to free iovas, just call the entry_dtor on all remaining
* entries.
*/
- if (!iovad->entry_dtor)
- return;
-
for_each_possible_cpu(cpu) {
struct iova_fq *fq = per_cpu_ptr(iovad->fq, cpu);
int idx;

fq_ring_for_each(idx, fq)
- iovad->entry_dtor(fq->entries[idx].data);
+ fq_entry_dtor(fq->entries[idx].freelist);
}
}

@@ -630,7 +632,7 @@ static void fq_flush_timeout(struct timer_list *t)

void queue_iova(struct iova_domain *iovad,
unsigned long pfn, unsigned long pages,
- unsigned long data)
+ struct page *freelist)
{
struct iova_fq *fq;
unsigned long flags;
@@ -664,7 +666,7 @@ void queue_iova(struct iova_domain *iovad,

fq->entries[idx].iova_pfn = pfn;
fq->entries[idx].pages = pages;
- fq->entries[idx].data = data;
+ fq->entries[idx].freelist = freelist;
fq->entries[idx].counter = atomic64_read(&iovad->fq_flush_start_cnt);

spin_unlock_irqrestore(&fq->lock, flags);
diff --git a/include/linux/iova.h b/include/linux/iova.h
index 71d8a2de6635..e746d8e41449 100644
--- a/include/linux/iova.h
+++ b/include/linux/iova.h
@@ -40,9 +40,6 @@ struct iova_domain;
/* Call-Back from IOVA code into IOMMU drivers */
typedef void (* iova_flush_cb)(struct iova_domain *domain);

-/* Destructor for per-entry data */
-typedef void (* iova_entry_dtor)(unsigned long data);
-
/* Number of entries per Flush Queue */
#define IOVA_FQ_SIZE 256

@@ -53,7 +50,7 @@ typedef void (* iova_entry_dtor)(unsigned long data);
struct iova_fq_entry {
unsigned long iova_pfn;
unsigned long pages;
- unsigned long data;
+ struct page *freelist;
u64 counter; /* Flush counter when this entrie was added */
};

@@ -88,9 +85,6 @@ struct iova_domain {
iova_flush_cb flush_cb; /* Call-Back function to flush IOMMU
TLBs */

- iova_entry_dtor entry_dtor; /* IOMMU driver specific destructor for
- iova entry */
-
struct timer_list fq_timer; /* Timer to regularily empty the
flush-queues */
atomic_t fq_timer_on; /* 1 when timer is active, 0
@@ -146,15 +140,14 @@ void free_iova_fast(struct iova_domain *iovad, unsigned long pfn,
unsigned long size);
void queue_iova(struct iova_domain *iovad,
unsigned long pfn, unsigned long pages,
- unsigned long data);
+ struct page *freelist);
unsigned long alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
unsigned long limit_pfn, bool flush_rcache);
struct iova *reserve_iova(struct iova_domain *iovad, unsigned long pfn_lo,
unsigned long pfn_hi);
void init_iova_domain(struct iova_domain *iovad, unsigned long granule,
unsigned long start_pfn);
-int init_iova_flush_queue(struct iova_domain *iovad,
- iova_flush_cb flush_cb, iova_entry_dtor entry_dtor);
+int init_iova_flush_queue(struct iova_domain *iovad, iova_flush_cb flush_cb);
struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn);
void put_iova_domain(struct iova_domain *iovad);
#else
@@ -189,12 +182,6 @@ static inline void free_iova_fast(struct iova_domain *iovad,
{
}

-static inline void queue_iova(struct iova_domain *iovad,
- unsigned long pfn, unsigned long pages,
- unsigned long data)
-{
-}
-
static inline unsigned long alloc_iova_fast(struct iova_domain *iovad,
unsigned long size,
unsigned long limit_pfn,
@@ -216,13 +203,6 @@ static inline void init_iova_domain(struct iova_domain *iovad,
{
}

-static inline int init_iova_flush_queue(struct iova_domain *iovad,
- iova_flush_cb flush_cb,
- iova_entry_dtor entry_dtor)
-{
- return -ENODEV;
-}
-
static inline struct iova *find_iova(struct iova_domain *iovad,
unsigned long pfn)
{
--
2.28.0.dirty