From: Sven Peter via iommu <iommu@lists.linux-foundation.org>
To: iommu@lists.linux-foundation.org, Robin Murphy <robin.murphy@arm.com>
Cc: Arnd Bergmann <arnd@kernel.org>, Sven Peter <sven@svenpeter.dev>,
Marc Zyngier <maz@kernel.org>, Hector Martin <marcan@marcan.st>,
linux-kernel@vger.kernel.org, Alexander Graf <graf@amazon.com>,
Mohamed Mediouni <mohamed.mediouni@caramail.com>,
Will Deacon <will@kernel.org>,
Alyssa Rosenzweig <alyssa@rosenzweig.io>
Subject: [PATCH v3 5/6] iommu: Introduce __IOMMU_DOMAIN_LP
Date: Tue, 19 Oct 2021 18:37:36 +0200 [thread overview]
Message-ID: <20211019163737.46269-6-sven@svenpeter.dev> (raw)
In-Reply-To: <20211019163737.46269-1-sven@svenpeter.dev>
__IOMMU_DOMAIN_LP (large pages) indicates that a domain can handle
conditions where PAGE_SIZE might be smaller than the IOMMU page size.
Always allow attaching trusted devices to such domains and set the flag for
IOMMU_DOMAIN_DMA, which can now handle these situations.
Note that untrusted devices are not yet supported. Those require
additional changes to allow aligning swiotlb buffers to granularities
larger than PAGE_SIZE.
Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
drivers/iommu/iommu.c | 9 +++++++--
include/linux/iommu.h | 13 +++++++++++--
2 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 28896739964b..66bba6a6bb28 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1976,10 +1976,15 @@ void iommu_domain_free(struct iommu_domain *domain)
}
EXPORT_SYMBOL_GPL(iommu_domain_free);
-static int iommu_check_page_size(struct iommu_domain *domain)
+static int iommu_check_page_size(struct iommu_domain *domain,
+ struct device *dev)
{
+ bool trusted = !(dev_is_pci(dev) && to_pci_dev(dev)->untrusted);
+
if (!iommu_is_paging_domain(domain))
return 0;
+ if (iommu_is_large_pages_domain(domain) && trusted)
+ return 0;
if (!(domain->pgsize_bitmap & (PAGE_SIZE | (PAGE_SIZE - 1)))) {
pr_warn("IOMMU pages cannot exactly represent CPU pages.\n");
@@ -2007,7 +2012,7 @@ static int __iommu_attach_device(struct iommu_domain *domain,
* only limit domain->pgsize_bitmap after having attached the first
* device.
*/
- ret = iommu_check_page_size(domain);
+ ret = iommu_check_page_size(domain, dev);
if (ret) {
__iommu_detach_device(domain, dev);
return ret;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index cabd25879613..1f1af59d0522 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -62,6 +62,8 @@ struct iommu_domain_geometry {
implementation */
#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
#define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */
+#define __IOMMU_DOMAIN_LP (1U << 4) /* Support for PAGE_SIZE smaller
+ than IOMMU page size */
/*
* This are the possible domain-types
@@ -81,10 +83,12 @@ struct iommu_domain_geometry {
#define IOMMU_DOMAIN_IDENTITY (__IOMMU_DOMAIN_PT)
#define IOMMU_DOMAIN_UNMANAGED (__IOMMU_DOMAIN_PAGING)
#define IOMMU_DOMAIN_DMA (__IOMMU_DOMAIN_PAGING | \
- __IOMMU_DOMAIN_DMA_API)
+ __IOMMU_DOMAIN_DMA_API | \
+ __IOMMU_DOMAIN_LP)
#define IOMMU_DOMAIN_DMA_FQ (__IOMMU_DOMAIN_PAGING | \
__IOMMU_DOMAIN_DMA_API | \
- __IOMMU_DOMAIN_DMA_FQ)
+ __IOMMU_DOMAIN_DMA_FQ | \
+ __IOMMU_DOMAIN_LP)
struct iommu_domain {
unsigned type;
@@ -106,6 +110,11 @@ static inline bool iommu_is_paging_domain(struct iommu_domain *domain)
return domain->type & __IOMMU_DOMAIN_PAGING;
}
+static inline bool iommu_is_large_pages_domain(struct iommu_domain *domain)
+{
+ return domain->type & __IOMMU_DOMAIN_LP;
+}
+
enum iommu_cap {
IOMMU_CAP_CACHE_COHERENCY, /* IOMMU can enforce cache coherent DMA
transactions */
--
2.25.1
_______________________________________________
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iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu
next prev parent reply other threads:[~2021-10-19 16:39 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-19 16:37 [PATCH v3 0/6] Support IOMMU page sizes larger than the CPU page size Sven Peter via iommu
2021-10-19 16:37 ` [PATCH v3 1/6] iommu/dma: Disable get_sgtable for granule > PAGE_SIZE Sven Peter via iommu
2021-10-19 16:37 ` [PATCH v3 2/6] iommu/dma: Support granule > PAGE_SIZE in dma_map_sg Sven Peter via iommu
2021-10-19 16:37 ` [PATCH v3 3/6] iommu/dma: Support granule > PAGE_SIZE allocations Sven Peter via iommu
2021-10-19 16:37 ` [PATCH v3 4/6] iommu: Move IOMMU pagesize check to attach_device Sven Peter via iommu
2021-10-20 5:21 ` Lu Baolu
2021-10-20 14:22 ` Marc Zyngier
2021-10-21 2:22 ` Lu Baolu
2021-10-21 8:10 ` Marc Zyngier
2021-10-22 2:52 ` Lu Baolu
2021-10-22 8:06 ` Marc Zyngier
2021-10-22 13:39 ` Robin Murphy
2021-10-23 8:40 ` Sven Peter via iommu
2021-10-21 8:31 ` Sven Peter via iommu
2021-10-19 16:37 ` Sven Peter via iommu [this message]
2021-10-19 16:37 ` [PATCH v3 6/6] iommu/dart: Remove force_bypass logic Sven Peter via iommu
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