[PATCH v4 01/24] iommu: Pull IOVA cookie management into the core

[Robin Murphy]

Now that everyone has converged on iommu-dma for IOMMU_DOMAIN_DMA
support, we can abandon the notion of drivers being responsible for the
cookie type, and consolidate all the management into the core code.

CC: Yong Wu <yong.wu@xxxxxxxxxxxx>
CC: Chunyan Zhang <chunyan.zhang@xxxxxxxxxx>
CC: Maxime Ripard <mripard@xxxxxxxxxx>
Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>

---

v3: Use a simpler temporary check instead of trying to be clever with
    the error code
---
 drivers/iommu/iommu.c | 7 +++++++
 include/linux/iommu.h | 3 ++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f2cda9950bd5..b65fcc66ffa4 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -7,6 +7,7 @@
 #define pr_fmt(fmt)    "iommu: " fmt
 
 #include <linux/device.h>
+#include <linux/dma-iommu.h>
 #include <linux/kernel.h>
 #include <linux/bits.h>
 #include <linux/bug.h>
@@ -1946,6 +1947,11 @@ static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
 	/* Assume all sizes by default; the driver may override this later */
 	domain->pgsize_bitmap  = bus->iommu_ops->pgsize_bitmap;
 
+	/* Temporarily avoid -EEXIST while drivers still get their own cookies */
+	if (type == IOMMU_DOMAIN_DMA && !domain->iova_cookie && iommu_get_dma_cookie(domain)) {
+		iommu_domain_free(domain);
+		domain = NULL;
+	}
 	return domain;
 }
 
@@ -1957,6 +1963,7 @@ EXPORT_SYMBOL_GPL(iommu_domain_alloc);
 
 void iommu_domain_free(struct iommu_domain *domain)
 {
+	iommu_put_dma_cookie(domain);
 	domain->ops->domain_free(domain);
 }
 EXPORT_SYMBOL_GPL(iommu_domain_free);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 4997c78e2670..141779d76035 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -40,6 +40,7 @@ struct iommu_domain;
 struct notifier_block;
 struct iommu_sva;
 struct iommu_fault_event;
+struct iommu_dma_cookie;
 
 /* iommu fault flags */
 #define IOMMU_FAULT_READ	0x0
@@ -86,7 +87,7 @@ struct iommu_domain {
 	iommu_fault_handler_t handler;
 	void *handler_token;
 	struct iommu_domain_geometry geometry;
-	void *iova_cookie;
+	struct iommu_dma_cookie *iova_cookie;
 };
 
 enum iommu_cap {
-- 
2.25.1