linux-toradex.git/lib/genalloc.c, branch v6.4-rc1

lib/genalloc: use try_cmpxchg in {set,clear}_bits_ll

2023-02-03T06:50:05+00:00

Use try_cmpxchg instead of cmpxchg (*ptr, old, new) == old in
{set,clear}_bits_ll.  x86 CMPXCHG instruction returns success in ZF flag,
so this change saves a compare after cmpxchg (and related move instruction
in front of cmpxchg).

Also, try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg
fails.

Note that the value from *ptr should be read using READ_ONCE to prevent
the compiler from merging, refetching or reordering the read.

The patch also declares these two functions inline, to ensure inlining.

No functional change intended.

Link: https://lkml.kernel.org/r/20230118150703.4024-1-ubizjak@gmail.com
Signed-off-by: Uros Bizjak 
Signed-off-by: Andrew Morton

all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate

2022-01-15T16:47:31+00:00

find_first{,_zero}_bit is a more effective analogue of 'next' version if
start == 0. This patch replaces 'next' with 'first' where things look
trivial.

Signed-off-by: Yury Norov 
Tested-by: Wolfram Sang

lib/genalloc: add parameter description to fix doc compile warning

2021-05-07T02:24:12+00:00

Commit 52fbf1134d47 ("lib/genalloc.c: fix allocation of aligned buffer
from non-aligned chunk") added a new parameter 'start_addr' w/o
description for it. That causes some doc compile warning:

  lib/genalloc.c:649: warning: Function parameter or member 'start_addr' not described in 'gen_pool_first_fit'
  lib/genalloc.c:667: warning: Function parameter or member 'start_addr' not described in 'gen_pool_first_fit_align'
  lib/genalloc.c:694: warning: Function parameter or member 'start_addr' not described in 'gen_pool_fixed_alloc'
  lib/genalloc.c:729: warning: Function parameter or member 'start_addr' not described in 'gen_pool_first_fit_order_align'
  lib/genalloc.c:752: warning: Function parameter or member 'start_addr' not described in 'gen_pool_best_fit'

This fixes it by adding a parameter descriptions.

Link: https://lkml.kernel.org/r/20210405132021.131231-1-alexs@kernel.org
Signed-off-by: Alex Shi 
Cc: Alexey Skidanov 
Cc: Huang Shijie 
Cc: Alex Shi 
Cc: Bhaskar Chowdhury 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/genalloc.c: Fix a typo

2021-05-07T02:24:12+00:00

s/macthing/matching/

Link: https://lkml.kernel.org/r/20210326131530.30481-1-unixbhaskar@gmail.com
Signed-off-by: Bhaskar Chowdhury 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/genalloc.c: change return type to unsigned long for bitmap_set_ll

2021-02-26T17:41:04+00:00

Just as bitmap_clear_ll(), change return type to unsigned long
for bitmap_set_ll to avoid the possible overflow in future.

Link: https://lkml.kernel.org/r/20210105031644.2771-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/genalloc: fix the overflow when size is too big

2020-12-29T23:36:49+00:00

Some graphic card has very big memory on chip, such as 32G bytes.

In the following case, it will cause overflow:

    pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE);
    ret = gen_pool_add(pool, 0x1000000, SZ_32G, NUMA_NO_NODE);

    va = gen_pool_alloc(pool, SZ_4G);

The overflow occurs in gen_pool_alloc_algo_owner():

		....
		size = nbits << order;
		....

The @nbits is "int" type, so it will overflow.
Then the gen_pool_avail() will return the wrong value.

This patch converts some "int" to "unsigned long", and
changes the compare code in while.

Link: https://lkml.kernel.org/r/20201229060657.3389-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie 
Reported-by: Shi Jiasheng 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr

2019-12-05T03:44:13+00:00

Follow the kernel conventions, rename addr_in_gen_pool to
gen_pool_has_addr.

[sjhuang@iluvatar.ai: fix Documentation/ too]
 Link: http://lkml.kernel.org/r/20181229015914.5573-1-sjhuang@iluvatar.ai
Link: http://lkml.kernel.org/r/20181228083950.20398-1-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie 
Reviewed-by: Andrew Morton 
Cc: Russell King 
Cc: Arnd Bergmann 
Cc: Greg Kroah-Hartman 
Cc: Christoph Hellwig 
Cc: Marek Szyprowski 
Cc: Robin Murphy 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

lib/genalloc.c: export symbol addr_in_gen_pool

2019-12-05T03:44:13+00:00

We use addr_in_gen_pool() in a driver module.  So export it.

Link: http://lkml.kernel.org/r/20181224070622.22197-2-sjhuang@iluvatar.ai
Signed-off-by: Huang Shijie 
Reviewed-by: Andrew Morton 
Cc: Alexey Skidanov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

genalloc: Fix a set of docs build warnings

2019-10-07T15:10:38+00:00

Commit 795ee30648c7 ("lib/genalloc: introduce chunk owners") made a number
of changes to the genalloc API and implementation but did not update the
documentation to match, leading to these docs build warnings:

  ./lib/genalloc.c:1: warning: 'gen_pool_add_virt' not found
  ./lib/genalloc.c:1: warning: 'gen_pool_alloc' not found
  ./lib/genalloc.c:1: warning: 'gen_pool_free' not found
  ./lib/genalloc.c:1: warning: 'gen_pool_alloc_algo' not found

Fix these by updating the docs to match new function locations and names,
and by completing the update of one kerneldoc comment.

Fixes: 795ee30648c7 ("lib/genalloc: introduce chunk owners")
Acked-by: Dan Williams 
Signed-off-by: Jonathan Corbet

Merge tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping

2019-07-12T22:13:55+00:00

Pull dma-mapping updates from Christoph Hellwig:

 - move the USB special case that bounced DMA through a device bar into
   the USB code instead of handling it in the common DMA code (Laurentiu
   Tudor and Fredrik Noring)

 - don't dip into the global CMA pool for single page allocations
   (Nicolin Chen)

 - fix a crash when allocating memory for the atomic pool failed during
   boot (Florian Fainelli)

 - move support for MIPS-style uncached segments to the common code and
   use that for MIPS and nios2 (me)

 - make support for DMA_ATTR_NON_CONSISTENT and
   DMA_ATTR_NO_KERNEL_MAPPING generic (me)

 - convert nds32 to the generic remapping allocator (me)

* tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping: (29 commits)
  dma-mapping: mark dma_alloc_need_uncached as __always_inline
  MIPS: only select ARCH_HAS_UNCACHED_SEGMENT for non-coherent platforms
  usb: host: Fix excessive alignment restriction for local memory allocations
  lib/genalloc.c: Add algorithm, align and zeroed family of DMA allocators
  nios2: use the generic uncached segment support in dma-direct
  nds32: use the generic remapping allocator for coherent DMA allocations
  arc: use the generic remapping allocator for coherent DMA allocations
  dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code
  dma-direct: handle DMA_ATTR_NON_CONSISTENT in common code
  dma-mapping: add a dma_alloc_need_uncached helper
  openrisc: remove the partial DMA_ATTR_NON_CONSISTENT support
  arc: remove the partial DMA_ATTR_NON_CONSISTENT support
  arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support
  ARM: dma-mapping: allow larger DMA mask than supported
  dma-mapping: truncate dma masks to what dma_addr_t can hold
  iommu/dma: Apply dma_{alloc,free}_contiguous functions
  dma-remap: Avoid de-referencing NULL atomic_pool
  MIPS: use the generic uncached segment support in dma-direct
  dma-direct: provide generic support for uncached kernel segments
  au1100fb: fix DMA API abuse
  ...