linux-toradex.git/include/linux/swiotlb.h, branch v3.12-rc7

x86, kdump: Set crashkernel_low automatically

2013-04-17T19:35:32+00:00

Chao said that kdump does does work well on his system on 3.8
without extra parameter, even iommu does not work with kdump.
And now have to append crashkernel_low=Y in first kernel to make
kdump work.

We have now modified crashkernel=X to allocate memory beyong 4G (if
available) and do not allocate low range for crashkernel if the user
does not specify that with crashkernel_low=Y.  This causes regression
if iommu is not enabled.  Without iommu, swiotlb needs to be setup in
first 4G and there is no low memory available to second kernel.

Set crashkernel_low automatically if the user does not specify that.

For system that does support IOMMU with kdump properly, user could
specify crashkernel_low=0 to save that 72M low ram.

-v3: add swiotlb_size() according to Konrad.
-v4: add comments what 8M is for according to hpa.
     also update more crashkernel_low= in kernel-parameters.txt
-v5: update changelog according to Vivek.
-v6: Change description about swiotlb referring according to HATAYAMA.

Reported-by: WANG Chao 
Tested-by: WANG Chao 
Signed-off-by: Yinghai Lu 
Link: http://lkml.kernel.org/r/1366089828-19692-2-git-send-email-yinghai@kernel.org
Acked-by: Vivek Goyal 
Signed-off-by: H. Peter Anvin

x86: Don't panic if can not alloc buffer for swiotlb

2013-01-30T03:36:53+00:00

Normal boot path on system with iommu support:
swiotlb buffer will be allocated early at first and then try to initialize
iommu, if iommu for intel or AMD could setup properly, swiotlb buffer
will be freed.

The early allocating is with bootmem, and could panic when we try to use
kdump with buffer above 4G only, or with memmap to limit mem under 4G.
for example: memmap=4095M$1M to remove memory under 4G.

According to Eric, add _nopanic version and no_iotlb_memory to fail
map single later if swiotlb is still needed.

-v2: don't pass nopanic, and use -ENOMEM return value according to Eric.
     panic early instead of using swiotlb_full to panic...according to Eric/Konrad.
-v3: make swiotlb_init to be notpanic, but will affect:
     arm64, ia64, powerpc, tile, unicore32, x86.
-v4: cleanup swiotlb_init by removing swiotlb_init_with_default_size.

Suggested-by: Eric W. Biederman 
Signed-off-by: Yinghai Lu 
Link: http://lkml.kernel.org/r/1359058816-7615-36-git-send-email-yinghai@kernel.org
Reviewed-and-tested-by: Konrad Rzeszutek Wilk 
Cc: Joerg Roedel 
Cc: Ralf Baechle 
Cc: Jeremy Fitzhardinge 
Cc: Kyungmin Park 
Cc: Marek Szyprowski 
Cc: Arnd Bergmann 
Cc: Andrzej Pietrasiewicz 
Cc: linux-mips@linux-mips.org
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: Shuah Khan 
Signed-off-by: H. Peter Anvin

swiotlb: Do not export swiotlb_bounce since there are no external consumers

2012-10-30T13:32:07+00:00

Currently swiotlb is the only consumer for swiotlb_bounce.  Since that is the
case it doesn't make much sense to be exporting it so make it a static
function only.

In addition we can save a few more lines of code by making it so that it
accepts the DMA address as a physical address instead of a virtual one.  This
is the last piece in essentially pushing all of the DMA address values to use
physical addresses in swiotlb.

In order to clarify things since we now have 2 physical addresses in use
inside of swiotlb_bounce I am renaming phys to orig_addr, and dma_addr to
tlb_addr.  This way is should be clear that orig_addr is contained within
io_orig_addr and tlb_addr is an address within the io_tlb_addr buffer.

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

swiotlb: Use physical addresses instead of virtual in swiotlb_tbl_sync_single

2012-10-30T13:32:07+00:00

This change makes it so that the sync functionality also uses physical
addresses.  This helps to further reduce the use of virt_to_phys and
phys_to_virt functions.

In order to clarify things since we now have 2 physical addresses in use
inside of swiotlb_tbl_sync_single I am renaming phys to orig_addr, and
dma_addr to tlb_addr.  This way is should be clear that orig_addr is
contained within io_orig_addr and tlb_addr is an address within the
io_tlb_addr buffer.

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

swiotlb: Use physical addresses for swiotlb_tbl_unmap_single

2012-10-30T13:32:07+00:00

This change makes it so that the unmap functionality also uses physical
addresses.  This helps to further reduce the use of virt_to_phys and
phys_to_virt functions.

In order to clarify things since we now have 2 physical addresses in use
inside of swiotlb_tbl_unmap_single I am renaming phys to orig_addr, and
dma_addr to tlb_addr.  This way is should be clear that orig_addr is
contained within io_orig_addr and tlb_addr is an address within the
io_tlb_addr buffer.

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

swiotlb: Return physical addresses when calling swiotlb_tbl_map_single

2012-10-30T13:32:06+00:00

This change makes it so that swiotlb_tbl_map_single will return a physical
address instead of a virtual address when called.  The advantage to this once
again is that we are avoiding a number of virt_to_phys and phys_to_virt
translations by working with everything as a physical address.

One change I had to make in order to support using physical addresses is that
I could no longer trust 0 to be a invalid physical address on all platforms.
So instead I made it so that ~0 is returned on error.  This should never be a
valid return value as it implies that only one byte would be available for
use.

In order to clarify things since we now have 2 physical addresses in use
inside of swiotlb_tbl_map_single I am renaming phys to orig_addr, and
dma_addr to tlb_addr.  This way is should be clear that orig_addr is
contained within io_orig_addr and tlb_addr is an address within the
io_tlb_addr buffer.

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

swiotlb: add the late swiotlb initialization function with iotlb memory

2012-08-21T18:47:25+00:00

This enables the caller to initialize swiotlb with its own iotlb
memory late in the bootup.

See git commit eb605a5754d050a25a9f00d718fb173f24c486ef
"swiotlb: add swiotlb_tbl_map_single library function" which will
explain the full details of what it can be used for.

CC: FUJITA Tomonori 
[v1: Fold in smatch warning]
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Expose swiotlb_nr_tlb function to modules

2011-12-06T10:38:03+00:00

As a mechanism to detect whether SWIOTLB is enabled or not.
We also fix the spelling - it was swioltb instead of
swiotlb.

CC: FUJITA Tomonori 
[v1: Ripped out swiotlb_enabled]
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Export swioltb_nr_tbl and utilize it as appropiate.

2011-06-06T19:41:16+00:00

By default the io_tlb_nslabs is set to zero, and gets set to
whatever value is passed in via swiotlb_init_with_tbl function.
The default value passed in is 64MB. However, if the user provides
the 'swiotlb=' the default value is ignored and
the value provided by the user is used... Except when the SWIOTLB
is used under Xen - there the default value of 64MB is used and
the Xen-SWIOTLB has no mechanism to get the 'io_tlb_nslabs' filled
out by setup_io_tlb_npages functions. This patch provides a function
for the Xen-SWIOTLB to call to see if the io_tlb_nslabs is set
and if so use that value.

Signed-off-by: FUJITA Tomonori 
Signed-off-by: Konrad Rzeszutek Wilk

swiotlb: Make swiotlb bookkeeping functions visible in the header file.

2010-06-07T15:59:27+00:00

We put the functions dealing with the operations on
the SWIOTLB buffer in the header and make those functions non-static.
And also make the functions exported via EXPORT_SYMBOL_GPL.

See "swiotlb: swiotlb: add swiotlb_tbl_map_single library function" for
full description of patchset.

[v2: swiotlb_sync_single_range_for_* no more. Remove usage.]

Signed-off-by: Konrad Rzeszutek Wilk 
Acked-by: FUJITA Tomonori 
Tested-by: Albert Herranz