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From: Aneesh V <aneesh@ti.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH v3 05/10] armv7: integrate cache maintenance support
Date: Tue, 17 May 2011 15:50:06 +0530	[thread overview]
Message-ID: <4DD24BD6.5060608@ti.com> (raw)
In-Reply-To: <20110515185534.9B1F01491B06@gemini.denx.de>

Hi Wolfgang,

On Monday 16 May 2011 12:25 AM, Wolfgang Denk wrote:
> Dear Aneesh V,
>
> In message<1305202276-27784-6-git-send-email-aneesh@ti.com>  you wrote:
>> - Enable I-cache on bootup
>> - Enable MMU and D-cache immediately after relocation
>> 	- Do necessary initialization before enabling d-cache and MMU
>
> Would it be possible to do this even _before_ relocation, so to speed
> up memory accesses during relocation?  Of course, proper invalidates/
> flushes will be needed before jumping to the RAM address, but I guess
> this would save a bit of boot times?

I intentionally kept it after  relocation to avoid un-necessary 
complexities.
Relocation is a case of self-modifying code. In Harvard architectures
like armv7 there will be coherency issues unless we flush the entire
D-cache(range based operation may be equally or more expensive) and
invalidate the entire I-cache.

So, in effect everything has to be flushed to memory before you jump to
the new location. There may be a small advantage because flushing from
cache allows for bursting to the DDR where as bursting is not possible
when d-cache is disabled. But I think this is not worth the trouble.

best regards,
Aneesh

  reply	other threads:[~2011-05-17 10:20 UTC|newest]

Thread overview: 105+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-03-08 13:07 [U-Boot] [PATCH v2 00/10] armv7: cache maintenance operations Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 01/10] arm: make default implementation of cache_flush() weakly linked Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 02/10] armv7: add miscellaneous utility macros Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 03/10] armv7: cache maintenance operations for armv7 Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 04/10] armv7: replace CONFIG_L2_OFF with CONFIG_SYS_NO_L2CACHE Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 05/10] armv7: integrate cache maintenance support Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 06/10] arm: minor fixes for cache and mmu handling Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 07/10] armv7: add PL310 support to u-boot Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 08/10] armv7: adapt omap4 to the new cache maintenance framework Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 09/10] armv7: adapt omap3 " Aneesh V
2011-03-08 13:07 ` [U-Boot] [PATCH v2 10/10] armv7: adapt s5pc1xx " Aneesh V
2011-04-27  1:05 ` [U-Boot] [PATCH v2 00/10] armv7: cache maintenance operations Simon Glass
2011-05-05  4:48   ` Simon Glass
2011-05-10 10:25     ` Aneesh V
2011-05-12 12:11 ` [U-Boot] [PATCH v3 " Aneesh V
2011-05-12 12:11 ` [U-Boot] [PATCH v3 01/10] arm: make default implementation of cache_flush() weakly linked Aneesh V
2011-05-12 12:11 ` [U-Boot] [PATCH v3 02/10] armv7: add miscellaneous utility macros Aneesh V
2011-05-15 18:44   ` Wolfgang Denk
2011-05-15 22:15     ` Simon Glass
2011-05-16  2:23       ` Eric Cooper
2011-05-16 14:50         ` Simon Glass
2011-05-16 15:52           ` Wolfgang Denk
2011-05-16  5:51       ` Wolfgang Denk
2011-05-17  3:47         ` Simon Glass
2011-05-17  5:27           ` Wolfgang Denk
2011-05-17  8:44             ` Aneesh V
2011-05-17  9:27               ` Wolfgang Denk
2011-05-31  7:54                 ` V, Aneesh
2011-06-01  2:13                   ` Simon Glass
2011-06-01  6:01                     ` Aneesh V
2011-05-16 15:07     ` Aneesh V
2011-06-06 15:57       ` Aneesh V
2011-06-06 18:50         ` Wolfgang Denk
2011-06-07  9:01           ` Aneesh V
2011-06-07 10:39             ` Wolfgang Denk
2011-06-07 12:14               ` Aneesh V
2011-06-07 15:19                 ` Simon Glass
2011-06-07 15:40                 ` Wolfgang Denk
2011-06-08 11:53                   ` Aneesh V
2011-06-08 21:41                     ` Wolfgang Denk
2011-06-14  8:45                       ` Aneesh V
2011-06-14 10:51                         ` Wolfgang Denk
2011-06-14 11:39                           ` Aneesh V
2011-06-14 13:53                             ` Wolfgang Denk
2011-06-14 15:11                               ` Simon Glass
2011-06-14 18:54                                 ` Wolfgang Denk
2011-06-15 15:19                                   ` Simon Glass
2011-06-15  8:48                               ` Aneesh V
2011-06-15  9:20                                 ` Wolfgang Denk
2011-06-15 11:01                                   ` Aneesh V
2011-06-15 12:04                                     ` Wolfgang Denk
2011-06-15 12:42                                       ` Graeme Russ
2011-06-15 12:51                                         ` Wolfgang Denk
2011-06-15 13:03                                           ` Graeme Russ
2011-06-16 11:07                                           ` Graeme Russ
2011-06-16 11:46                                             ` Wolfgang Denk
2011-06-16 23:58                                               ` Graeme Russ
2011-06-16  5:39                                         ` Aneesh V
2011-06-16  6:19                                           ` Graeme Russ
2011-06-16  8:15                                             ` Wolfgang Denk
2011-06-16 11:10                                               ` Graeme Russ
2011-05-12 12:11 ` [U-Boot] [PATCH v3 03/10] armv7: cache maintenance operations for armv7 Aneesh V
2011-05-15 18:51   ` Wolfgang Denk
2011-05-17  9:17     ` Aneesh V
2011-05-17  9:31       ` Wolfgang Denk
2011-05-17  9:37         ` Aneesh V
2011-05-17  9:58         ` Aneesh V
2011-06-16 14:17           ` Simon Glass
2011-05-12 12:11 ` [U-Boot] [PATCH v3 04/10] armv7: replace CONFIG_L2_OFF with CONFIG_SYS_NO_L2CACHE Aneesh V
2011-05-15 18:53   ` Wolfgang Denk
2011-05-17  9:59     ` Aneesh V
2011-05-17 11:09       ` Wolfgang Denk
2011-06-06 11:39         ` Aneesh V
2011-06-15 10:13           ` Wolfgang Denk
2011-05-12 12:11 ` [U-Boot] [PATCH v3 05/10] armv7: integrate cache maintenance support Aneesh V
2011-05-15 18:55   ` Wolfgang Denk
2011-05-17 10:20     ` Aneesh V [this message]
2011-05-17 11:14       ` Wolfgang Denk
2011-05-17 12:06         ` Aneesh V
2011-05-17 12:28           ` Wolfgang Denk
2011-05-17 13:28             ` Aneesh V
2011-05-17 21:37               ` Wolfgang Denk
2011-05-12 12:11 ` [U-Boot] [PATCH v3 06/10] arm: minor fixes for cache and mmu handling Aneesh V
2011-05-12 12:11 ` [U-Boot] [PATCH v3 07/10] armv7: add PL310 support to u-boot Aneesh V
2011-05-12 12:11 ` [U-Boot] [PATCH v3 08/10] armv7: adapt omap4 to the new cache maintenance framework Aneesh V
2011-05-15 18:57   ` Wolfgang Denk
2011-05-12 12:11 ` [U-Boot] [PATCH v3 09/10] armv7: adapt omap3 " Aneesh V
2011-05-15 18:58   ` Wolfgang Denk
2011-05-12 12:11 ` [U-Boot] [PATCH v3 10/10] armv7: adapt s5pc1xx " Aneesh V
2011-05-15 18:59   ` Wolfgang Denk
2011-06-17  9:30 ` [U-Boot] [PATCH v4 0/9] armv7: cache maintenance operations Aneesh V
2011-06-22 17:41   ` Albert ARIBAUD
2011-06-23  5:57     ` V, Aneesh
2011-06-23 19:24     ` Paulraj, Sandeep
2011-06-28  1:44       ` Minkyu Kang
2011-06-28  5:41   ` Albert ARIBAUD
2011-06-17  9:30 ` [U-Boot] [PATCH v4 1/9] arm: make default implementation of cache_flush() weakly linked Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 2/9] armv7: cache maintenance operations for armv7 Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 3/9] armv7: rename cache related CONFIG flags Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 4/9] armv7: integrate cache maintenance support Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 5/9] arm: minor fixes for cache and mmu handling Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 6/9] armv7: add PL310 support to u-boot Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 7/9] armv7: adapt omap4 to the new cache maintenance framework Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 8/9] armv7: adapt omap3 " Aneesh V
2011-06-17  9:30 ` [U-Boot] [PATCH v4 9/9] armv7: adapt s5pc1xx " Aneesh V

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