From: Sven Peter <sven@svenpeter.dev>
To: iommu@lists.linux-foundation.org
Cc: Sven Peter <sven@svenpeter.dev>, Joerg Roedel <joro@8bytes.org>,
Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Arnd Bergmann <arnd@kernel.org>,
Mohamed Mediouni <mohamed.mediouni@caramail.com>,
Alexander Graf <graf@amazon.com>,
Hector Martin <marcan@marcan.st>,
linux-kernel@vger.kernel.org
Subject: [RFC PATCH 3/3] iommu: Introduce __IOMMU_DOMAIN_LARGE_PAGES
Date: Fri, 6 Aug 2021 17:55:23 +0200 [thread overview]
Message-ID: <20210806155523.50429-4-sven@svenpeter.dev> (raw)
In-Reply-To: <20210806155523.50429-1-sven@svenpeter.dev>
__IOMMU_DOMAIN_LARGE_PAGES indicates that a domain can handle
conditions where PAGE_SIZE might be smaller than the IOMMU page size.
Always allow attaching devices to such domains and set the flag for
IOMMU_DOMAIN_DMA, which can now handle these situations.
Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
drivers/iommu/iommu.c | 2 ++
include/linux/iommu.h | 14 +++++++++-----
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5854a4ef5681..f0bfd76187b1 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1970,6 +1970,8 @@ static int iommu_check_page_size(struct iommu_domain *domain)
{
if (!(domain->type & __IOMMU_DOMAIN_PAGING))
return 0;
+ if (domain->type & __IOMMU_DOMAIN_LARGE_PAGES)
+ return 0;
if ((1 << __ffs(domain->pgsize_bitmap)) > PAGE_SIZE) {
pr_warn("IOMMU page size cannot represent CPU pages.\n");
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index e552ecfefcf7..1f97eac8a4b0 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -56,10 +56,13 @@ struct iommu_domain_geometry {
};
/* Domain feature flags */
-#define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */
-#define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API
- implementation */
-#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
+#define __IOMMU_DOMAIN_PAGING (1U << 0) /* Support for iommu_map/unmap */
+#define __IOMMU_DOMAIN_DMA_API (1U << 1) /* Domain for use in DMA-API
+ implementation */
+#define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */
+#define __IOMMU_DOMAIN_LARGE_PAGES (1U << 3) /* Domain can handle IOMMU page
+ sizes larger than the CPU
+ page size */
/*
* This are the possible domain-types
@@ -77,7 +80,8 @@ 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_LARGE_PAGES)
struct iommu_domain {
unsigned type;
--
2.25.1
prev parent reply other threads:[~2021-08-06 15:57 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-06 15:55 [RFC PATCH 0/3] iommu/dma-iommu: Support IOMMU page size larger than the CPU page size Sven Peter
2021-08-06 15:55 ` [RFC PATCH 1/3] iommu: Move IOMMU pagesize check to attach_device Sven Peter
2021-08-06 15:55 ` [RFC PATCH 2/3] iommu/dma-iommu: Support iovad->granule > PAGE_SIZE Sven Peter
2021-08-06 18:04 ` Robin Murphy
2021-08-07 8:41 ` Sven Peter
2021-08-09 18:37 ` Robin Murphy
2021-08-09 19:57 ` Sven Peter
2021-08-07 11:47 ` Sven Peter
2021-08-09 17:41 ` Robin Murphy
2021-08-09 20:45 ` Sven Peter
2021-08-10 9:51 ` Robin Murphy
2021-08-11 20:18 ` Sven Peter
2021-08-12 12:43 ` Robin Murphy
2021-08-06 15:55 ` Sven Peter [this message]
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