[PATCH v2 01/24] iommu: Pull IOVA cookie management into the core

Robin Murphy
2021-07-28T16:02:12Z

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: Marek Szyprowski <m.szyprowski@samsung.com>
CC: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
CC: Geert Uytterhoeven <geert+renesas@glider.be>
CC: Yong Wu <yong.wu@mediatek.com>
CC: Heiko Stuebner <heiko@sntech.de>
CC: Chunyan Zhang <chunyan.zhang@unisoc.com>
CC: Chunyan Zhang <chunyan.zhang@unisoc.com>
CC: Maxime Ripard <mripard@kernel.org>
CC: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
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..ea5a9ea8d431 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 ignore -EEXIST while drivers still get their own cookies */
+ if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(domain) == -ENOMEM) {
+ 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