14 Dec, 2014
2 commits
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kmemleak will add allocations as objects to a pool. The memory allocated
for each object in this pool is periodically searched for pointers to
other allocated objects. This only works for memory that is mapped into
the kernel's virtual address space, which happens not to be the case for
most CMA regions.Furthermore, CMA regions are typically used to store data transferred to
or from a device and therefore don't contain pointers to other objects.Without this, the kernel crashes on the first execution of the
scan_gray_list() because it tries to access highmem. Perhaps a more
appropriate fix would be to reject any object that can't map to a kernel
virtual address?[akpm@linux-foundation.org: add comment]
[akpm@linux-foundation.org: fix comment, per Catalin]
[sfr@canb.auug.org.au: include linux/io.h for phys_to_virt()]
Signed-off-by: Thierry Reding
Cc: Michal Nazarewicz
Cc: Marek Szyprowski
Cc: Joonsoo Kim
Cc: "Aneesh Kumar K.V"
Cc: Catalin Marinas
Signed-off-by: Stephen Rothwell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The alignment in cma_alloc() was done w.r.t. the bitmap. This is a
problem when, for example:- a device requires 16M (order 12) alignment
- the CMA region is not 16 M alignedIn such a case, can result with the CMA region starting at, say,
0x2f800000 but any allocation you make from there will be aligned from
there. Requesting an allocation of 32 M with 16 M alignment will result
in an allocation from 0x2f800000 to 0x31800000, which doesn't work very
well if your strange device requires 16M alignment.Change to use bitmap_find_next_zero_area_off() to account for the
difference in alignment at reserve-time and alloc-time.Signed-off-by: Gregory Fong
Acked-by: Michal Nazarewicz
Cc: Marek Szyprowski
Cc: Joonsoo Kim
Cc: Kukjin Kim
Cc: Laurent Pinchart
Cc: Laura Abbott
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Dec, 2014
1 commit
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high_memory isn't direct mapped memory so retrieving it's physical address
isn't appropriate. But, it would be useful to check physical address of
highmem boundary so it's justfiable to get physical address from it. In
x86, there is a validation check if CONFIG_DEBUG_VIRTUAL and it triggers
following boot failure reported by Ingo....
BUG: Int 6: CR2 00f06f53
...
Call Trace:
dump_stack+0x41/0x52
early_idt_handler+0x6b/0x6b
cma_declare_contiguous+0x33/0x212
dma_contiguous_reserve_area+0x31/0x4e
dma_contiguous_reserve+0x11d/0x125
setup_arch+0x7b5/0xb63
start_kernel+0xb8/0x3e6
i386_start_kernel+0x79/0x7dTo fix boot regression, this patch implements workaround to avoid
validation check in x86 when retrieving physical address of high_memory.
__pa_nodebug() used by this patch is implemented only in x86 so there is
no choice but to use dirty #ifdef.[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Joonsoo Kim
Reported-by: Ingo Molnar
Tested-by: Ingo Molnar
Cc: Marek Szyprowski
Cc: Russell King
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Oct, 2014
4 commits
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Casting physical addresses to unsigned long and using %lu truncates the
values on systems where physical addresses are larger than 32 bits. Use
%pa and get rid of the cast instead.Signed-off-by: Laurent Pinchart
Acked-by: Michal Nazarewicz
Acked-by: Geert Uytterhoeven
Signed-off-by: Marek Szyprowski -
Commit 95b0e655f914 ("ARM: mm: don't limit default CMA region only to
low memory") extended CMA memory reservation to allow usage of high
memory. It relied on commit f7426b983a6a ("mm: cma: adjust address limit
to avoid hitting low/high memory boundary") to ensure that the reserved
block never crossed the low/high memory boundary. While the
implementation correctly lowered the limit, it failed to consider the
case where the base..limit range crossed the low/high memory boundary
with enough space on each side to reserve the requested size on either
low or high memory.Rework the base and limit adjustment to fix the problem. The function
now starts by rejecting the reservation altogether for fixed
reservations that cross the boundary, tries to reserve from high memory
first and then falls back to low memory.Signed-off-by: Laurent Pinchart
Signed-off-by: Marek Szyprowski -
The fixed parameter to cma_declare_contiguous() tells the function
whether the given base address must be honoured or should be considered
as a hint only. The API considers a zero base address as meaning any
base address, which must never be considered as a fixed value.Part of the implementation correctly checks both fixed and base != 0,
but two locations check the fixed value only. Set fixed to false when
base is 0 to fix that and simplify the code.Signed-off-by: Laurent Pinchart
Acked-by: Michal Nazarewicz
Signed-off-by: Marek Szyprowski -
If activation of the CMA area fails its mutex won't be initialized,
leading to an oops at allocation time when trying to lock the mutex. Fix
this by setting the cma area count field to 0 when activation fails,
leading to allocation returning NULL immediately.Cc: # v3.17
Signed-off-by: Laurent Pinchart
Acked-by: Michal Nazarewicz
Signed-off-by: Marek Szyprowski
14 Oct, 2014
2 commits
-
Add a function to create CMA region from previously reserved memory and
add support for handling 'shared-dma-pool' reserved-memory device tree
nodes.Based on previous code provided by Josh Cartwright
Signed-off-by: Marek Szyprowski
Cc: Arnd Bergmann
Cc: Michal Nazarewicz
Cc: Grant Likely
Cc: Laura Abbott
Cc: Josh Cartwright
Cc: Joonsoo Kim
Cc: Kyungmin Park
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The current cma bitmap aligned mask computation is incorrect. It could
cause an unexpected alignment when using cma_alloc() if the wanted align
order is larger than cma->order_per_bit.Take kvm for example (PAGE_SHIFT = 12), kvm_cma->order_per_bit is set to
6. When kvm_alloc_rma() tries to alloc kvm_rma_pages, it will use 15 as
the expected align value. After using the current implementation however,
we get 0 as cma bitmap aligned mask other than 511.This patch fixes the cma bitmap aligned mask calculation.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Weijie Yang
Acked-by: Michal Nazarewicz
Cc: Joonsoo Kim
Cc: "Aneesh Kumar K.V"
Cc: [3.17]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Oct, 2014
1 commit
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Russell King recently noticed that limiting default CMA region only to low
memory on ARM architecture causes serious memory management issues with
machines having a lot of memory (which is mainly available as high
memory). More information can be found the following thread:
http://thread.gmane.org/gmane.linux.ports.arm.kernel/348441/Those two patches removes this limit letting kernel to put default CMA
region into high memory when this is possible (there is enough high memory
available and architecture specific DMA limit fits).This should solve strange OOM issues on systems with lots of RAM (i.e.
>1GiB) and large (>256M) CMA area.This patch (of 2):
Automatically allocated regions should not cross low/high memory boundary,
because such regions cannot be later correctly initialized due to spanning
across two memory zones. This patch adds a check for this case and a
simple code for moving region to low memory if automatically selected
address might not fit completely into high memory.Signed-off-by: Marek Szyprowski
Acked-by: Michal Nazarewicz
Cc: Daniel Drake
Cc: Minchan Kim
Cc: Russell King
Cc: Joonsoo Kim
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Aug, 2014
4 commits
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We don't need explicit 'CMA:' prefix, since we already define prefix
'cma:' in pr_fmt. So remove it.Signed-off-by: Joonsoo Kim
Acked-by: Michal Nazarewicz
Reviewed-by: Zhang Yanfei
Cc: "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: Benjamin Herrenschmidt
Cc: Paul Mackerras
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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 -
We can remove one call sites for clear_cma_bitmap() if we first call it
before checking error number.Signed-off-by: Joonsoo Kim
Acked-by: Minchan Kim
Reviewed-by: Michal Nazarewicz
Reviewed-by: Zhang Yanfei
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 -
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