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authorRobin Murphy <robin.murphy@arm.com>2018-12-10 15:00:31 +0100
committerChristoph Hellwig <hch@lst.de>2018-12-11 14:32:12 +0100
commita8a4c98fc9ac84ee9e068fbb16210d2ab8cfefe0 (patch)
tree216128ca9be3b97e771a4f1b0f31aae1acee9a2a /Documentation/x86
parentdma-debug: Make leak-like behaviour apparent (diff)
downloadlinux-a8a4c98fc9ac84ee9e068fbb16210d2ab8cfefe0.tar.xz
linux-a8a4c98fc9ac84ee9e068fbb16210d2ab8cfefe0.zip
x86/dma/amd-gart: Stop resizing dma_debug_entry pool
dma-debug is now capable of adding new entries to its pool on-demand if the initial preallocation was insufficient, so the IOMMU_LEAK logic no longer needs to explicitly change the pool size. This does lose it the ability to save a couple of megabytes of RAM by reducing the pool size below its default, but it seems unlikely that that is a realistic concern these days (or indeed that anyone is actively debugging AGP drivers' DMA usage any more). Getting rid of dma_debug_resize_entries() will make room for further streamlining in the dma-debug code itself. Removing the call reveals quite a lot of cruft which has been useless for nearly a decade since commit 19c1a6f5764d ("x86 gart: reimplement IOMMU_LEAK feature by using DMA_API_DEBUG"), including the entire 'iommu=leak' parameter, which controlled nothing except whether dma_debug_resize_entries() was called or not. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Qian Cai <cai@lca.pw> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'Documentation/x86')
-rw-r--r--Documentation/x86/x86_64/boot-options.txt5
1 files changed, 1 insertions, 4 deletions
diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt
index ad6d2a80cf05..abc53886655e 100644
--- a/Documentation/x86/x86_64/boot-options.txt
+++ b/Documentation/x86/x86_64/boot-options.txt
@@ -209,7 +209,7 @@ IOMMU (input/output memory management unit)
mapping with memory protection, etc.
Kernel boot message: "PCI-DMA: Using Calgary IOMMU"
- iommu=[<size>][,noagp][,off][,force][,noforce][,leak[=<nr_of_leak_pages>]
+ iommu=[<size>][,noagp][,off][,force][,noforce]
[,memaper[=<order>]][,merge][,fullflush][,nomerge]
[,noaperture][,calgary]
@@ -228,9 +228,6 @@ IOMMU (input/output memory management unit)
allowed Overwrite iommu off workarounds for specific chipsets.
fullflush Flush IOMMU on each allocation (default).
nofullflush Don't use IOMMU fullflush.
- leak Turn on simple iommu leak tracing (only when
- CONFIG_IOMMU_LEAK is on). Default number of leak pages
- is 20.
memaper[=<order>] Allocate an own aperture over RAM with size 32MB<<order.
(default: order=1, i.e. 64MB)
merge Do scatter-gather (SG) merging. Implies "force"