From: jy0922.shim@samsung.com (Joonyoung Shim)
Date: Wed, 07 Jul 2010 11:15:59 +0900
Subject: [PATCH] ARM: S5PV210: Fix on SECTION_SIZE_BITS on	S5PV210/S5PC110.
In-Reply-To: <013001cb1d62$de72ff30$9b58fd90$%kim@samsung.com>
References: <1278391007-11144-1-git-send-email-kgene.kim@samsung.com>
	<20100706071245.GA5058@n2100.arm.linux.org.uk>
	<013001cb1d62$de72ff30$9b58fd90$%kim@samsung.com>
Message-ID: <4C33E35F.8060409@samsung.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 7/7/2010 8:27 AM, Kukjin Kim wrote:
> Russell King wrote:
> Hi Russell :-)
> 
>> On Tue, Jul 06, 2010 at 01:36:47PM +0900, Kukjin Kim wrote:
>>> This patch fixes on SECTION_SIZE_BITS for Sparsemem on S5PV210/S5PC110.
>>> Because smallest size of a bank on S5PV210/S5PC110 is aligned by 16MB.
>>> So each section's maximum size should be 16MB.
>> What is the spacing of chunks of memory, and minimum alignment of those
>> chunks in physical address space?
> 
> Some S5PC110(MCP D-type) has only available 80MiB in a bank.
> So the space accounts for 432MiB in a DMC0, but larger memory(256MiB +
> 128MiB) exists in a DMC1.
> 
> As you know, the size of a section should be a power of 2 and a physical
> address space of a section should be contiguous.
> If a section size is greater than 16MiB, a section have a hole. So the
> SECTION_SIZE_BITS should be 16MiB.
> 
>> Also, what is the maximum physical address which memory can be located?
> 
> Following is memory map of S5PV210/S5PC110.
> 
> 0x80000000  -------------------
>             |          |
> 0x70000000  |          |
>             |          |
> 0x60000000  |  DMC 1  |  up to 1GiB
>             |          |
> 0x50000000  |          |
>             |          |
> 0x40000000  ----------------- 
>             |          |
> 0x30000000  |  DMC 0  |  up to 512MiB
>             |          |
> 0x20000000  -------------------
> 

Please see arch/arm/include/asm/sparsemem.h

 * SECTION_SIZE_BITS: The number of physical address bits to cover                                
 *   the maximum amount of memory in a section.

I know 1 bank of S5PV210/S5PC110 have maximum 256MB, so i think
SECTION_SIZE_BITS is 28.