On 31/05/18 08:42, Zhen Lei wrote:
1. Save the related domain pointer in struct iommu_dma_cookie, make iovad
capable call domain->ops->flush_iotlb_all to flush TLB.
2. Define a new iommu capable: IOMMU_CAP_NON_STRICT, which used to indicate
that the iommu domain support non-strict mode.
3. During the iommu domain initialization phase, call capable() to check
whether it support non-strcit mode. If so, call init_iova_flush_queue
to register iovad->flush_cb callback.
4. All unmap(contains iova-free) APIs will finally invoke __iommu_dma_unmap
-->iommu_dma_free_iova. Use iovad->flush_cb to check whether its related
iommu support non-strict mode or not, and call IOMMU_DOMAIN_IS_STRICT to
make sure the IOMMU_DOMAIN_UNMANAGED domain always follow strict mode.
Once again, this is a whole load of complexity for a property which
could just be statically encoded at allocation, e.g. in the cookie type.
Signed-off-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx>
---
drivers/iommu/dma-iommu.c | 29 ++++++++++++++++++++++++++---
include/linux/iommu.h | 3 +++
2 files changed, 29 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4e885f7..2e116d9 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -55,6 +55,7 @@ struct iommu_dma_cookie {
};
struct list_head msi_page_list;
spinlock_t msi_lock;
+ struct iommu_domain *domain;
};
static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
@@ -64,7 +65,8 @@ static inline size_t cookie_msi_granule(struct iommu_dma_cookie *cookie)
return PAGE_SIZE;
}
-static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
+static struct iommu_dma_cookie *cookie_alloc(struct iommu_domain *domain,
+ enum iommu_dma_cookie_type type)
{
struct iommu_dma_cookie *cookie;
@@ -73,6 +75,7 @@ static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
spin_lock_init(&cookie->msi_lock);
INIT_LIST_HEAD(&cookie->msi_page_list);
cookie->type = type;
+ cookie->domain = domain;
}
return cookie;
}
@@ -94,7 +97,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
if (domain->iova_cookie)
return -EEXIST;
- domain->iova_cookie = cookie_alloc(IOMMU_DMA_IOVA_COOKIE);
+ domain->iova_cookie = cookie_alloc(domain, IOMMU_DMA_IOVA_COOKIE);
if (!domain->iova_cookie)
return -ENOMEM;
@@ -124,7 +127,7 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
if (domain->iova_cookie)
return -EEXIST;
- cookie = cookie_alloc(IOMMU_DMA_MSI_COOKIE);
+ cookie = cookie_alloc(domain, IOMMU_DMA_MSI_COOKIE);
if (!cookie)
return -ENOMEM;
@@ -261,6 +264,17 @@ static int iova_reserve_iommu_regions(struct device *dev,
return ret;
}
+static void iova_flush_iotlb_all(struct iova_domain *iovad)
iommu_dma_flush...
+{
+ struct iommu_dma_cookie *cookie;
+ struct iommu_domain *domain;
+
+ cookie = container_of(iovad, struct iommu_dma_cookie, iovad);
+ domain = cookie->domain;
+
+ domain->ops->flush_iotlb_all(domain);
+}
+
/**
* iommu_dma_init_domain - Initialise a DMA mapping domain
* @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
@@ -276,6 +290,7 @@ static int iova_reserve_iommu_regions(struct device *dev,
int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
u64 size, struct device *dev)
{
+ const struct iommu_ops *ops = domain->ops;
struct iommu_dma_cookie *cookie = domain->iova_cookie;
struct iova_domain *iovad = &cookie->iovad;
unsigned long order, base_pfn, end_pfn;
@@ -313,6 +328,11 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
init_iova_domain(iovad, 1UL << order, base_pfn);
+ if (ops->capable && ops->capable(IOMMU_CAP_NON_STRICT)) {
+ BUG_ON(!ops->flush_iotlb_all);
+ init_iova_flush_queue(iovad, iova_flush_iotlb_all, NULL);
+ }
+
return iova_reserve_iommu_regions(dev, domain);
}
EXPORT_SYMBOL(iommu_dma_init_domain);
@@ -392,6 +412,9 @@ static void iommu_dma_free_iova(struct iommu_dma_cookie *cookie,
/* The MSI case is only ever cleaning up its most recent allocation */
if (cookie->type == IOMMU_DMA_MSI_COOKIE)
cookie->msi_iova -= size;
+ else if (!IOMMU_DOMAIN_IS_STRICT(cookie->domain) && iovad->flush_cb)
+ queue_iova(iovad, iova_pfn(iovad, iova),
+ size >> iova_shift(iovad), 0);
else
free_iova_fast(iovad, iova_pfn(iovad, iova),
size >> iova_shift(iovad));
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 39b3150..01ff569 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -87,6 +87,8 @@ struct iommu_domain_geometry {
__IOMMU_DOMAIN_DMA_API)
#define IOMMU_STRICT 1
+#define IOMMU_DOMAIN_IS_STRICT(domain) \
+ (domain->type == IOMMU_DOMAIN_UNMANAGED)
struct iommu_domain {
unsigned type;
@@ -103,6 +105,7 @@ enum iommu_cap {
transactions */
IOMMU_CAP_INTR_REMAP, /* IOMMU supports interrupt isolation */
IOMMU_CAP_NOEXEC, /* IOMMU_NOEXEC flag */
+ IOMMU_CAP_NON_STRICT, /* IOMMU supports non-strict mode */
This isn't a property of the IOMMU, it depends purely on the driver
implementation. I think it also doesn't matter anyway - if a caller asks
for lazy unmapping on their domain but the IOMMU driver just does strict
unmaps anyway because that's all it supports, there's no actual harm done.
Robin.
};
/*
--
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