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From: Suzuki.Poulose@arm•com (Suzuki K. Poulose)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCHv3 02/11] arm64: Handle section maps for swapper/idmap
Date: Wed, 14 Oct 2015 16:08:43 +0100	[thread overview]
Message-ID: <561E6FFB.3020005@arm.com> (raw)
In-Reply-To: <20151014145158.GA4422@leverpostej>

On 14/10/15 15:51, Mark Rutland wrote:
>>>> +/* With 4K pages, we use section maps. */

>> /*
>>   * ARM64 kernel is guaranteed to be loaded at 2M aligned
>>   * address (as per booting requirements). Hence we can use
>>   * section mapping with 4K (section size = 2M) and not with
>>   * 16K(section size = 32M) or 64K (section size = 512M).
>>   */
>
> That sounds much better. I hadn't figured out why myself, so thanks for
> the explanation :)
>
> However, there's one minor nit: the start of memory below the kernel is
> 2M aligned, but the offset means that the kernel itself is not loaded at
> a 2M aligned address.

Oh yes

>
> So how about:
>
> /*
>   * The linear mapping and the start of memory are both 2M aligned (per
>   * the arm64 booting.txt requirements). Hence we can use section mapping
>   * with 4K (section size = 2M) but not with 16K (section size = 32M) or
>   * 64K (section size = 512M).
>   */

Will add this

Thanks
Suzuki

  reply	other threads:[~2015-10-14 15:08 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-14 11:20 [PATCHv3 00/11] arm64: 16K translation granule support Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 01/11] arm64: Move swapper pagetable definitions Suzuki K. Poulose
2015-10-14 11:42   ` Mark Rutland
2015-10-14 12:41     ` Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 02/11] arm64: Handle section maps for swapper/idmap Suzuki K. Poulose
2015-10-14 12:06   ` Mark Rutland
2015-10-14 13:21     ` Suzuki K. Poulose
2015-10-14 14:51       ` Mark Rutland
2015-10-14 15:08         ` Suzuki K. Poulose [this message]
2015-10-14 15:14           ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 03/11] arm64: Introduce helpers for page table levels Suzuki K. Poulose
2015-10-14 17:07   ` Mark Rutland
2015-10-15  9:35     ` Suzuki K. Poulose
2015-10-15 10:37       ` Mark Rutland
2015-10-15 11:40       ` Christoffer Dall
2015-10-15 11:37   ` Christoffer Dall
2015-10-15 12:44     ` Mark Rutland
2015-10-15 13:14       ` Suzuki K. Poulose
2015-10-15 13:30         ` Christoffer Dall
2015-10-15 13:48           ` Suzuki K. Poulose
2015-10-15 14:15             ` Christoffer Dall
2015-10-14 11:20 ` [PATCHv3 04/11] arm64: Calculate size for idmap_pg_dir at compile time Suzuki K. Poulose
2015-10-14 17:12   ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 05/11] arm64: Handle 4 level page table for swapper Suzuki K. Poulose
2015-10-14 17:15   ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 06/11] arm64: Clean config usages for page size Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 07/11] arm64: Kconfig: Fix help text about AArch32 support with 64K pages Suzuki K. Poulose
2015-10-14 17:16   ` Mark Rutland
2015-10-14 11:20 ` [PATCHv3 08/11] arm64: Check for selected granule support Suzuki K. Poulose
2015-10-14 17:24   ` Mark Rutland
2015-10-14 17:32     ` Mark Rutland
2015-10-15  9:45     ` Suzuki K. Poulose
2015-10-15 10:39       ` Mark Rutland
2015-10-14 21:13   ` Jeremy Linton
2015-10-15  9:48     ` Suzuki K. Poulose
2015-10-15 10:45     ` Mark Rutland
2015-10-15 11:25       ` Suzuki K. Poulose
2015-10-15 12:37         ` Mark Rutland
2015-10-15 12:58           ` Suzuki K. Poulose
2015-10-16  8:03             ` Ard Biesheuvel
2015-10-15 14:47         ` Jeremy Linton
2015-10-15 15:02           ` Suzuki K. Poulose
2015-10-15 15:11           ` Mark Rutland
2015-10-16  8:11             ` Ard Biesheuvel
2015-10-14 11:20 ` [PATCHv3 09/11] arm64: Add page size to the kernel image header Suzuki K. Poulose
2015-10-14 17:27   ` Mark Rutland
2015-10-15  9:19     ` Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 10/11] arm64: Add 16K page size support Suzuki K. Poulose
2015-10-14 15:40   ` Jeremy Linton
2015-10-14 15:53     ` Suzuki K. Poulose
2015-10-15 14:06   ` Mark Rutland
2015-10-15 14:48     ` Suzuki K. Poulose
2015-10-15 15:36       ` Steve Capper
2015-10-15 15:48         ` Suzuki K. Poulose
2015-10-14 11:20 ` [PATCHv3 11/11] arm64: 36 bit VA Suzuki K. Poulose

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