From: Taniya Das <tdas@codeaurora.org>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org, tsoni@codeaurora.org
Subject: Re: arm_memblock_steal() API usage
Date: Wed, 04 Apr 2012 10:36:05 +0530 [thread overview]
Message-ID: <4F7BD6BD.7040102@codeaurora.org> (raw)
In-Reply-To: <20120403073053.GO24211@n2100.arm.linux.org.uk>
RMK,
On 03-Apr-12 1:00 PM, Russell King - ARM Linux wrote:
> On Tue, Apr 03, 2012 at 09:34:03AM +0530, Taniya Das wrote:
>> I have a requirement where I need around ~100 bytes of memory to save
>> contents of
>> registers to a non-cached area before going into low power mode.
>>
>> I did do some analysis on a 1GB RAM device of allocating 8 bytes using
>> the API and the below was the result
>> was showing allocating only 8 bytes.
>>
>> API used : - arm_memblock_steal(SZ_8, SZ_64K);--> physical address
>> returned is 0x3b1f0000
> It's silly to use this for the above purpose. Why not just use kmalloc
> and cache flushing to ensure that the data is pushed out to RAM?
We don't want to do a kmalloc and flush, we want to do something similar
to how OMAP4
does, keeping aside a chunk of RAM for saving the contents. But my only
concern what will
be the minimum amount of memory allocated by arm_memblock_steal?
>> Also is this API advisable for devices with low system RAM?
> No.
--
Thanks& Regards,
Taniya Das.
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
WARNING: multiple messages have this Message-ID (diff)
From: tdas@codeaurora.org (Taniya Das)
To: linux-arm-kernel@lists.infradead.org
Subject: arm_memblock_steal() API usage
Date: Wed, 04 Apr 2012 10:36:05 +0530 [thread overview]
Message-ID: <4F7BD6BD.7040102@codeaurora.org> (raw)
In-Reply-To: <20120403073053.GO24211@n2100.arm.linux.org.uk>
RMK,
On 03-Apr-12 1:00 PM, Russell King - ARM Linux wrote:
> On Tue, Apr 03, 2012 at 09:34:03AM +0530, Taniya Das wrote:
>> I have a requirement where I need around ~100 bytes of memory to save
>> contents of
>> registers to a non-cached area before going into low power mode.
>>
>> I did do some analysis on a 1GB RAM device of allocating 8 bytes using
>> the API and the below was the result
>> was showing allocating only 8 bytes.
>>
>> API used : - arm_memblock_steal(SZ_8, SZ_64K);--> physical address
>> returned is 0x3b1f0000
> It's silly to use this for the above purpose. Why not just use kmalloc
> and cache flushing to ensure that the data is pushed out to RAM?
We don't want to do a kmalloc and flush, we want to do something similar
to how OMAP4
does, keeping aside a chunk of RAM for saving the contents. But my only
concern what will
be the minimum amount of memory allocated by arm_memblock_steal?
>> Also is this API advisable for devices with low system RAM?
> No.
--
Thanks& Regards,
Taniya Das.
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
next prev parent reply other threads:[~2012-04-04 5:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-03 4:04 arm_memblock_steal() API usage Taniya Das
2012-04-03 4:04 ` Taniya Das
2012-04-03 7:30 ` Russell King - ARM Linux
2012-04-03 7:30 ` Russell King - ARM Linux
2012-04-04 5:06 ` Taniya Das [this message]
2012-04-04 5:06 ` Taniya Das
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