From: Peter Zijlstra <peterz@infradead.org>
To: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: linux-arch@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, stable@vger.kernel.org,
David Laight <David.Laight@ACULAB.COM>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Greg KH <greg@kroah.com>, Thomas Gleixner <tglx@linutronix.de>,
linux-snps-arc@lists.infradead.org
Subject: Re: [PATCH v3] devres: Explicitly align datai[] to 64-bit
Date: Mon, 9 Jul 2018 15:54:09 +0200 [thread overview]
Message-ID: <20180709135409.GQ2476@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20180709134550.29541-1-abrodkin@synopsys.com>
On Mon, Jul 09, 2018 at 04:45:50PM +0300, Alexey Brodkin wrote:
> diff --git a/drivers/base/devres.c b/drivers/base/devres.c
> index f98a097e73f2..d65327cb83c9 100644
> --- a/drivers/base/devres.c
> +++ b/drivers/base/devres.c
> @@ -24,8 +24,12 @@ struct devres_node {
>
> struct devres {
> struct devres_node node;
> - /* -- 3 pointers */
> - unsigned long long data[]; /* guarantee ull alignment */
> + /*
> + * data[] must be 64 bit aligned even on 32 bit architectures
> + * because it might be accessed by instructions that require
> + * aligned memory arguments such as atomic64_t.
> + */
> + u8 __aligned(8) data[];
> };
From a quick reading in Documentation/driver-model/devres.txt this
devres muck is supposed to be device memory, right?
atomics (as in atomic*_t) are not defined for use on mmio.
wth kind of code is relying on this?
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Cc: linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org,
linux-arch@vger.kernel.org,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
David Laight <David.Laight@ACULAB.COM>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will.deacon@arm.com>, Greg KH <greg@kroah.com>,
stable@vger.kernel.org
Subject: Re: [PATCH v3] devres: Explicitly align datai[] to 64-bit
Date: Mon, 9 Jul 2018 15:54:09 +0200 [thread overview]
Message-ID: <20180709135409.GQ2476@hirez.programming.kicks-ass.net> (raw)
Message-ID: <20180709135409.1SthS0PLwQSgRyAZdPrantuXEXwg6UhF6n_K4zvmigk@z> (raw)
In-Reply-To: <20180709134550.29541-1-abrodkin@synopsys.com>
On Mon, Jul 09, 2018 at 04:45:50PM +0300, Alexey Brodkin wrote:
> diff --git a/drivers/base/devres.c b/drivers/base/devres.c
> index f98a097e73f2..d65327cb83c9 100644
> --- a/drivers/base/devres.c
> +++ b/drivers/base/devres.c
> @@ -24,8 +24,12 @@ struct devres_node {
>
> struct devres {
> struct devres_node node;
> - /* -- 3 pointers */
> - unsigned long long data[]; /* guarantee ull alignment */
> + /*
> + * data[] must be 64 bit aligned even on 32 bit architectures
> + * because it might be accessed by instructions that require
> + * aligned memory arguments such as atomic64_t.
> + */
> + u8 __aligned(8) data[];
> };
next prev parent reply other threads:[~2018-07-09 13:54 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-09 13:45 [PATCH v3] devres: Explicitly align datai[] to 64-bit Alexey Brodkin
2018-07-09 13:45 ` Alexey Brodkin
2018-07-09 13:54 ` Peter Zijlstra [this message]
2018-07-09 13:54 ` Peter Zijlstra
2018-07-09 14:04 ` Mark Rutland
2018-07-09 14:04 ` Mark Rutland
2018-07-09 14:10 ` Geert Uytterhoeven
2018-07-09 14:10 ` Geert Uytterhoeven
2018-07-09 14:07 ` Alexey Brodkin
2018-07-09 14:07 ` Alexey Brodkin
2018-07-09 14:07 ` Peter Zijlstra
2018-07-09 14:07 ` Peter Zijlstra
2018-07-09 14:10 ` Peter Zijlstra
2018-07-09 14:10 ` Peter Zijlstra
2018-07-09 14:33 ` Alexey Brodkin
2018-07-09 14:33 ` Alexey Brodkin
2018-07-09 14:49 ` Peter Zijlstra
2018-07-09 14:49 ` Peter Zijlstra
2018-07-09 14:53 ` Alexey Brodkin
2018-07-09 14:53 ` Alexey Brodkin
2018-10-04 16:19 ` Alexey Brodkin
2018-10-04 16:19 ` Alexey Brodkin
2018-07-09 15:02 ` David Laight
2018-07-09 15:02 ` David Laight
2018-07-09 15:14 ` Peter Zijlstra
2018-07-09 15:14 ` Peter Zijlstra
2018-07-09 15:29 ` Mark Rutland
2018-07-09 15:29 ` Mark Rutland
2018-07-09 15:34 ` Peter Zijlstra
2018-07-09 15:34 ` Peter Zijlstra
2018-07-09 15:45 ` Peter Zijlstra
2018-07-09 15:45 ` Peter Zijlstra
2018-07-09 15:48 ` Mark Rutland
2018-07-09 15:48 ` Mark Rutland
2018-07-09 16:10 ` David Laight
2018-07-09 16:10 ` David Laight
2018-07-09 20:28 ` Vineet Gupta
2018-07-09 20:28 ` Vineet Gupta
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