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| author | Alexey Brodkin <alexey.brodkin@synopsys.com> | 2018-10-31 16:25:47 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-11-11 20:40:04 +0100 |
| commit | a66d972465d15b1d89281258805eb8b47d66bd36 (patch) | |
| tree | ec2a59ba96a3ab10277197653eb4c76d2a0825cb /drivers | |
| parent | Linux 4.20-rc1 (diff) | |
| download | linux-a66d972465d15b1d89281258805eb8b47d66bd36.tar.xz linux-a66d972465d15b1d89281258805eb8b47d66bd36.zip | |
devres: Align data[] to ARCH_KMALLOC_MINALIGN
Initially we bumped into problem with 32-bit aligned atomic64_t
on ARC, see [1]. And then during quite lengthly discussion Peter Z.
mentioned ARCH_KMALLOC_MINALIGN which IMHO makes perfect sense.
If allocation is done by plain kmalloc() obtained buffer will be
ARCH_KMALLOC_MINALIGN aligned and then why buffer obtained via
devm_kmalloc() should have any other alignment?
This way we at least get the same behavior for both types of
allocation.
[1] http://lists.infradead.org/pipermail/linux-snps-arc/2018-July/004009.html
[2] http://lists.infradead.org/pipermail/linux-snps-arc/2018-July/004036.html
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Greg KH <greg@kroah.com>
Cc: <stable@vger.kernel.org> # 4.8+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/base/devres.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/base/devres.c b/drivers/base/devres.c index 4aaf00d2098b..e038e2b3b7ea 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -26,8 +26,14 @@ struct devres_node { struct devres { struct devres_node node; - /* -- 3 pointers */ - unsigned long long data[]; /* guarantee ull alignment */ + /* + * Some archs want to perform DMA into kmalloc caches + * and need a guaranteed alignment larger than + * the alignment of a 64-bit integer. + * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same + * buffer alignment as if it was allocated by plain kmalloc(). + */ + u8 __aligned(ARCH_KMALLOC_MINALIGN) data[]; }; struct devres_group { |