linux-stable.git/lib/swiotlb.c, branch linux-4.15.y

swiotlb: suppress warning when __GFP_NOWARN is set

2018-02-22T14:39:54+00:00

commit d0bc0c2a31c95002d37c3cc511ffdcab851b3256 upstream.

TTM tries to allocate coherent memory in chunks of 2MB first to improve
TLB efficiency and falls back to allocating 4K pages if that fails.

Suppress the warning when the 2MB allocations fails since there is a
valid fall back path.

Signed-off-by: Christian König 
Reported-by: Mike Galbraith 
Acked-by: Konrad Rzeszutek Wilk 
Bug: https://bugs.freedesktop.org/show_bug.cgi?id=104082
Signed-off-by: Christoph Hellwig 
Signed-off-by: Greg Kroah-Hartman

x86/mm: Add DMA support for SEV memory encryption

2017-11-07T14:35:58+00:00

DMA access to encrypted memory cannot be performed when SEV is active.
In order for DMA to properly work when SEV is active, the SWIOTLB bounce
buffers must be used.

Signed-off-by: Tom Lendacky 
Signed-off-by: Brijesh Singh 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Borislav Petkov C
Tested-by: Borislav Petkov 
Cc: kvm@vger.kernel.org
Cc: Konrad Rzeszutek Wilk 
Cc: Borislav Petkov 
Link: https://lkml.kernel.org/r/20171020143059.3291-12-brijesh.singh@amd.com

swiotlb: Add warnings for use of bounce buffers with SME

2017-07-18T09:38:03+00:00

Add warnings to let the user know when bounce buffers are being used for
DMA when SME is active.  Since the bounce buffers are not in encrypted
memory, these notifications are to allow the user to determine some
appropriate action - if necessary.  Actions can range from utilizing an
IOMMU, replacing the device with another device that can support 64-bit
DMA, ignoring the message if the device isn't used much, etc.

Signed-off-by: Tom Lendacky 
Reviewed-by: Thomas Gleixner 
Cc: Alexander Potapenko 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brijesh Singh 
Cc: Dave Young 
Cc: Dmitry Vyukov 
Cc: Jonathan Corbet 
Cc: Konrad Rzeszutek Wilk 
Cc: Larry Woodman 
Cc: Linus Torvalds 
Cc: Matt Fleming 
Cc: Michael S. Tsirkin 
Cc: Paolo Bonzini 
Cc: Peter Zijlstra 
Cc: Radim Krčmář 
Cc: Rik van Riel 
Cc: Toshimitsu Kani 
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/d112564053c3f2e86ca634a8d4fa4abc0eb53a6a.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar

x86, swiotlb: Add memory encryption support

2017-07-18T09:38:03+00:00

Since DMA addresses will effectively look like 48-bit addresses when the
memory encryption mask is set, SWIOTLB is needed if the DMA mask of the
device performing the DMA does not support 48-bits. SWIOTLB will be
initialized to create decrypted bounce buffers for use by these devices.

Signed-off-by: Tom Lendacky 
Reviewed-by: Thomas Gleixner 
Cc: Alexander Potapenko 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Borislav Petkov 
Cc: Brijesh Singh 
Cc: Dave Young 
Cc: Dmitry Vyukov 
Cc: Jonathan Corbet 
Cc: Konrad Rzeszutek Wilk 
Cc: Larry Woodman 
Cc: Linus Torvalds 
Cc: Matt Fleming 
Cc: Michael S. Tsirkin 
Cc: Paolo Bonzini 
Cc: Peter Zijlstra 
Cc: Radim Krčmář 
Cc: Rik van Riel 
Cc: Toshimitsu Kani 
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/aa2d29b78ae7d508db8881e46a3215231b9327a7.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar

swiotlb: ensure that page-sized mappings are page-aligned

2017-01-15T17:37:24+00:00

Some drivers do depend on page mappings to be page aligned.

Swiotlb already enforces such alignment for mappings greater than page,
extend that to page-sized mappings as well.

Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine
assumes page-aligned mappings.

Signed-off-by: Nikita Yushchenko 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Sagi Grimberg 
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Export swiotlb_max_segment to users

2017-01-06T18:00:01+00:00

So they can figure out what is the optimal number of pages
that can be contingously stitched together without fear of
bounce buffer.

We also expose an mechanism for sub-users of SWIOTLB API, such
as Xen-SWIOTLB to set the max segment value. And lastly
if swiotlb=force is set (which mandates we bounce buffer everything)
we set max_segment so at least we can bounce buffer one 4K page
instead of a giant 512KB one for which we may not have space.

Signed-off-by: Konrad Rzeszutek Wilk 
Reported-and-Tested-by: Juergen Gross

swiotlb: Add swiotlb=noforce debug option

2016-12-19T14:05:20+00:00

On architectures like arm64, swiotlb is tied intimately to the core
architecture DMA support. In addition, ZONE_DMA cannot be disabled.

To aid debugging and catch devices not supporting DMA to memory outside
the 32-bit address space, add a kernel command line option
"swiotlb=noforce", which disables the use of bounce buffers.
If specified, trying to map memory that cannot be used with DMA will
fail, and a rate-limited warning will be printed.

Note that io_tlb_nslabs is set to 1, which is the minimal supported
value.

Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Convert swiotlb_force from int to enum

2016-12-19T14:05:20+00:00

Convert the flag swiotlb_force from an int to an enum, to prepare for
the advent of more possible values.

Suggested-by: Konrad Rzeszutek Wilk 
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Minor fix-ups for DMA_ATTR_SKIP_CPU_SYNC support

2016-11-10T20:56:19+00:00

I am updating the paths so that instead of trying to pass
"attr | DMA_ATTR_SKIP_CPU_SYNC" we instead just OR the value into attr and
then pass it since attr will not be used after we make the unmap call.

I realized there was one spot I had missed when I was applying the DMA
attribute to the DMA mapping exception handling.  This change corrects that.

Finally it looks like there is a stray blank line at the end of the
swiotlb_unmap_sg_attrs function that can be dropped.

Signed-off-by: Alexander Duyck 
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Add support for DMA_ATTR_SKIP_CPU_SYNC

2016-11-07T20:06:33+00:00

As a first step to making DMA_ATTR_SKIP_CPU_SYNC apply to architectures
beyond just ARM I need to make it so that the swiotlb will respect the
flag.  In order to do that I also need to update the swiotlb-xen since it
heavily makes use of the functionality.

Cc: Konrad Rzeszutek Wilk 
Signed-off-by: Alexander Duyck 
Signed-off-by: Konrad Rzeszutek Wilk