linux-toradex.git/kernel/dma/pool.c, branch v6.0-rc1

dma/pool: create dma atomic pool only if dma zone has managed pages

2022-01-15T14:30:29+00:00

Currently three dma atomic pools are initialized as long as the relevant
kernel codes are built in.  While in kdump kernel of x86_64, this is not
right when trying to create atomic_pool_dma, because there's no managed
pages in DMA zone.  In the case, DMA zone only has low 1M memory
presented and locked down by memblock allocator.  So no pages are added
into buddy of DMA zone.  Please check commit f1d4d47c5851 ("x86/setup:
Always reserve the first 1M of RAM").

Then in kdump kernel of x86_64, it always prints below failure message:

 DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
 swapper/0: page allocation failure: order:5, mode:0xcc1(GFP_KERNEL|GFP_DMA), nodemask=(null),cpuset=/,mems_allowed=0
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.13.0-0.rc5.20210611git929d931f2b40.42.fc35.x86_64 #1
 Hardware name: Dell Inc. PowerEdge R910/0P658H, BIOS 2.12.0 06/04/2018
 Call Trace:
  dump_stack+0x7f/0xa1
  warn_alloc.cold+0x72/0xd6
  __alloc_pages_slowpath.constprop.0+0xf29/0xf50
  __alloc_pages+0x24d/0x2c0
  alloc_page_interleave+0x13/0xb0
  atomic_pool_expand+0x118/0x210
  __dma_atomic_pool_init+0x45/0x93
  dma_atomic_pool_init+0xdb/0x176
  do_one_initcall+0x67/0x320
  kernel_init_freeable+0x290/0x2dc
  kernel_init+0xa/0x111
  ret_from_fork+0x22/0x30
 Mem-Info:
 ......
 DMA: failed to allocate 128 KiB GFP_KERNEL|GFP_DMA pool for atomic allocation
 DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA32 pool for atomic allocations

Here, let's check if DMA zone has managed pages, then create
atomic_pool_dma if yes.  Otherwise just skip it.

Link: https://lkml.kernel.org/r/20211223094435.248523-3-bhe@redhat.com
Fixes: 6f599d84231f ("x86/kdump: Always reserve the low 1M when the crashkernel option is specified")
Signed-off-by: Baoquan He 
Reviewed-by: Christoph Hellwig 
Acked-by: John Donnelly  
Reviewed-by: David Hildenbrand 
Cc: Marek Szyprowski 
Cc: Robin Murphy 
Cc: Borislav Petkov 
Cc: Christoph Lameter 
Cc: David Laight 
Cc: David Rientjes 
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim 
Cc: Pekka Enberg 
Cc: Vlastimil Babka 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

dma-pool: no need to check return value of debugfs_create functions

2020-11-27T09:33:42+00:00

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Signed-off-by: Tiezhu Yang 
Reviewed-by: Robin Murphy 
Signed-off-by: Christoph Hellwig

dma-mapping: merge into

2020-10-06T05:07:06+00:00

Move more nitty gritty DMA implementation details into the common
internal header.

Signed-off-by: Christoph Hellwig

dma-mapping: merge into

2020-10-06T05:07:04+00:00

Merge dma-contiguous.h into dma-map-ops.h, after removing the comment
describing the contiguous allocator into kernel/dma/contigous.c.

Signed-off-by: Christoph Hellwig

dma-direct: remove dma_direct_{alloc,free}_pages

2020-09-11T07:10:29+00:00

Just merge these helpers into the main dma_direct_{alloc,free} routines,
as the additional checks are always false for the two callers.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Robin Murphy

dma-pool: Fix an uninitialized variable bug in atomic_pool_expand()

2020-08-27T07:22:56+00:00

The "page" pointer can be used with out being initialized.

Fixes: d7e673ec2c8e ("dma-pool: Only allocate from CMA when in same memory zone")
Signed-off-by: Dan Carpenter 
Signed-off-by: Christoph Hellwig

dma-pool: Only allocate from CMA when in same memory zone

2020-08-14T14:27:05+00:00

There is no guarantee to CMA's placement, so allocating a zone specific
atomic pool from CMA might return memory from a completely different
memory zone. To get around this double check CMA's placement before
allocating from it.

Signed-off-by: Nicolas Saenz Julienne 
Signed-off-by: Christoph Hellwig

dma-pool: fix coherent pool allocations for IOMMU mappings

2020-08-14T14:27:00+00:00

When allocating coherent pool memory for an IOMMU mapping we don't care
about the DMA mask.  Move the guess for the initial GFP mask into the
dma_direct_alloc_pages and pass dma_coherent_ok as a function pointer
argument so that it doesn't get applied to the IOMMU case.

Signed-off-by: Christoph Hellwig 
Tested-by: Amit Pundir

dma-pool: do not allocate pool memory from CMA

2020-07-14T13:46:32+00:00

There is no guarantee to CMA's placement, so allocating a zone specific
atomic pool from CMA might return memory from a completely different
memory zone. So stop using it.

Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask")
Reported-by: Jeremy Linton 
Signed-off-by: Nicolas Saenz Julienne 
Tested-by: Jeremy Linton 
Acked-by: David Rientjes 
Signed-off-by: Christoph Hellwig

dma-pool: make sure atomic pool suits device

2020-07-14T13:42:33+00:00

When allocating DMA memory from a pool, the core can only guess which
atomic pool will fit a device's constraints. If it doesn't, get a safer
atomic pool and try again.

Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask")
Reported-by: Jeremy Linton 
Suggested-by: Robin Murphy 
Signed-off-by: Nicolas Saenz Julienne 
Signed-off-by: Christoph Hellwig