linux-stable.git/drivers/base/dma-contiguous.c, branch linux-3.17.y

mm, CMA: change cma_declare_contiguous() to obey coding convention

2014-08-07T01:01:16+00:00

Conventionally, we put output param to the end of param list and put the
'base' ahead of 'size', but cma_declare_contiguous() doesn't look like
that, so change it.

Additionally, move down cma_areas reference code to the position where
it is really needed.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Cc: Minchan Kim 
Cc: Paolo Bonzini 
Cc: Zhang Yanfei 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

CMA: generalize CMA reserved area management functionality

2014-08-07T01:01:16+00:00

Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc.  They have their own code
to manage CMA reserved area even if they looks really similar.  From my
guess, it is caused by some needs on bitmap management.  KVM side wants
to maintain bitmap not for 1 page, but for more size.  Eventually it use
bitmap where one bit represents 64 pages.

When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me.  I want to change
this situation and reduce future code management overhead through this
patch.

This change could also help developer who want to use CMA in their new
feature development, since they can use CMA easily without copying &
pasting this reserved area management code.

In previous patches, we have prepared some features to generalize CMA
reserved area management and now it's time to do it.  This patch moves
core functions to mm/cma.c and change DMA APIs to use these functions.

There is no functional change in DMA APIs.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Acked-by: Zhang Yanfei 
Acked-by: Minchan Kim 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Cc: Paolo Bonzini 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

DMA, CMA: support arbitrary bitmap granularity

2014-08-07T01:01:16+00:00

PPC KVM's CMA area management requires arbitrary bitmap granularity,
since they want to reserve very large memory and manage this region with
bitmap that one bit for several pages to reduce management overheads.
So support arbitrary bitmap granularity for following generalization.

[akpm@linux-foundation.org: s/1/1UL/]
Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Acked-by: Zhang Yanfei 
Acked-by: Minchan Kim 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Cc: Paolo Bonzini 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

DMA, CMA: support alignment constraint on CMA region

2014-08-07T01:01:16+00:00

PPC KVM's CMA area management needs alignment constraint on CMA region.
So support it to prepare generalization of CMA area management
functionality.

Additionally, add some comments which tell us why alignment constraint
is needed on CMA region.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Cc: Minchan Kim 
Cc: Paolo Bonzini 
Cc: Zhang Yanfei 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

DMA, CMA: separate core CMA management codes from DMA APIs

2014-08-07T01:01:16+00:00

To prepare future generalization work on CMA area management code, we
need to separate core CMA management codes from DMA APIs.  We will
extend these core functions to cover requirements of PPC KVM's CMA area
management functionality in following patches.  This separation helps us
not to touch DMA APIs while extending core functions.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Cc: Minchan Kim 
Cc: Paolo Bonzini 
Cc: Zhang Yanfei 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

DMA, CMA: fix possible memory leak

2014-06-23T23:47:44+00:00

We should free memory for bitmap when we find zone mismatch, otherwise
this memory will leak.

Additionally, I copy code comment from PPC KVM's CMA code to inform why
we need to check zone mis-match.

Signed-off-by: Joonsoo Kim 
Acked-by: Zhang Yanfei 
Reviewed-by: Michal Nazarewicz 
Reviewed-by: Aneesh Kumar K.V 
Acked-by: Minchan Kim 
Cc: "Aneesh Kumar K.V" 
Cc: Marek Szyprowski 
Cc: Michal Nazarewicz 
Cc: Paolo Bonzini 
Cc: Gleb Natapov 
Cc: Alexander Graf 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cma: add placement specifier for "cma=" kernel parameter

2014-06-04T23:53:57+00:00

Currently, "cma=" kernel parameter is used to specify the size of CMA,
but we can't specify where it is located.  We want to locate CMA below
4GB for devices only supporting 32-bit addressing on 64-bit systems
without iommu.

This enables to specify the placement of CMA by extending "cma=" kernel
parameter.

Examples:
 1. locate 64MB CMA below 4GB by "cma=64M@0-4G"
 2. locate 64MB CMA exact at 512MB by "cma=64M@512M"

Note that the DMA contiguous memory allocator on x86 assumes that
page_address() works for the pages to allocate.  So this change requires
to limit end address of contiguous memory area upto max_pfn_mapped to
prevent from locating it on highmem area by the argument of
dma_contiguous_reserve().

Signed-off-by: Akinobu Mita 
Cc: Marek Szyprowski 
Cc: Konrad Rzeszutek Wilk 
Cc: David Woodhouse 
Cc: Don Dutile 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Andi Kleen 
Cc: Yinghai Lu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

CMA: correct unlock target

2014-05-29T07:25:14+00:00

'cma: Remove potential deadlock situation' introduces per cma area mutex
for bitmap management. It is good, but there is one mistake. When we
can't find appropriate area in bitmap, we release cma_mutex global lock
rather than cma->lock and this is a bug. So fix it.

Signed-off-by: Joonsoo Kim 
Signed-off-by: Marek Szyprowski

drivers/base/dma-contiguous.c: erratum of dev_get_cma_area

2014-05-22T06:16:05+00:00

fix erratum get_dev_cma_area into dev_get_cma_area

Signed-off-by: Gioh Kim 
Signed-off-by: Marek Szyprowski

cma: Remove potential deadlock situation

2014-05-15T10:14:21+00:00

CMA locking is currently very coarse. The cma_mutex protects both
the bitmap and avoids concurrency with alloc_contig_range. There
are several situations which may result in a deadlock on the CMA
mutex currently, mostly involving AB/BA situations with alloc and
free. Fix this issue by protecting the bitmap with a mutex per CMA
region and use the existing mutex for protecting against concurrency
with alloc_contig_range.

Signed-off-by: Laura Abbott 
Signed-off-by: Marek Szyprowski