From: Mark Rutland <mark.rutland@arm.com>
To: Fuad Tabba <tabba@google.com>
Cc: linux-arm-kernel@lists.infradead.org, will@kernel.org,
catalin.marinas@arm.com, maz@kernel.org, ardb@kernel.org,
james.morse@arm.com, alexandru.elisei@arm.com,
suzuki.poulose@arm.com, robin.murphy@arm.com
Subject: Re: [PATCH v3 07/18] arm64: Downgrade flush_icache_range to invalidate
Date: Thu, 20 May 2021 15:15:55 +0100 [thread overview]
Message-ID: <20210520141555.GJ17233@C02TD0UTHF1T.local> (raw)
In-Reply-To: <20210520124406.2731873-8-tabba@google.com>
On Thu, May 20, 2021 at 01:43:55PM +0100, Fuad Tabba wrote:
> Since __flush_dcache_area is called right before,
> invalidate_icache_range is sufficient in this case.
>
> Rewrite the comment to better explain the rationale behind the
> cache maintenance operations used here.
>
> No functional change intended.
> Possible performance impact due to invalidating only the icache
> rather than invalidating and cleaning both caches.
>
> Reported-by: Catalin Marinas <catalin.marinas@arm.com>
> Reported-by: Will Deacon <will@kernel.org>
> Link: https://lore.kernel.org/linux-arch/20200511110014.lb9PEahJ4hVOYrbwIb_qUHXyNy9KQzNFdb_I3YlzY6A@z/
> Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> arch/arm64/kernel/machine_kexec.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c
> index 90a335c74442..a03944fd0cd4 100644
> --- a/arch/arm64/kernel/machine_kexec.c
> +++ b/arch/arm64/kernel/machine_kexec.c
> @@ -68,10 +68,14 @@ int machine_kexec_post_load(struct kimage *kimage)
> kimage->arch.kern_reloc = __pa(reloc_code);
> kexec_image_info(kimage);
>
> - /* Flush the reloc_code in preparation for its execution. */
> + /*
> + * For execution with the MMU off, reloc_code needs to be cleaned to the
> + * PoC and invalidated from the I-cache.
> + */
> __flush_dcache_area(reloc_code, arm64_relocate_new_kernel_size);
> - flush_icache_range((uintptr_t)reloc_code, (uintptr_t)reloc_code +
> - arm64_relocate_new_kernel_size);
> + invalidate_icache_range((uintptr_t)reloc_code,
> + (uintptr_t)reloc_code +
> + arm64_relocate_new_kernel_size);
>
> return 0;
> }
> --
> 2.31.1.751.gd2f1c929bd-goog
>
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-05-20 14:18 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-20 12:43 [PATCH v3 00/18] Tidy up cache.S Fuad Tabba
2021-05-20 12:43 ` [PATCH v3 01/18] arm64: assembler: replace `kaddr` with `addr` Fuad Tabba
2021-05-20 12:43 ` [PATCH v3 02/18] arm64: assembler: add conditional cache fixups Fuad Tabba
2021-05-20 12:43 ` [PATCH v3 03/18] arm64: Apply errata to swsusp_arch_suspend_exit Fuad Tabba
2021-05-20 12:46 ` Mark Rutland
2021-05-20 12:43 ` [PATCH v3 04/18] arm64: assembler: user_alt label optional Fuad Tabba
2021-05-20 12:57 ` Mark Rutland
2021-05-21 11:46 ` Fuad Tabba
2021-05-21 13:05 ` Mark Rutland
2021-05-20 12:43 ` [PATCH v3 05/18] arm64: Do not enable uaccess for flush_icache_range Fuad Tabba
2021-05-20 14:02 ` Mark Rutland
2021-05-20 15:37 ` Mark Rutland
2021-05-21 12:18 ` Mark Rutland
2021-05-25 11:18 ` Catalin Marinas
2021-05-20 12:43 ` [PATCH v3 06/18] arm64: Do not enable uaccess for invalidate_icache_range Fuad Tabba
2021-05-20 14:13 ` Mark Rutland
2021-05-25 11:18 ` Catalin Marinas
2021-05-20 12:43 ` [PATCH v3 07/18] arm64: Downgrade flush_icache_range to invalidate Fuad Tabba
2021-05-20 14:15 ` Mark Rutland [this message]
2021-05-25 11:18 ` Catalin Marinas
2021-05-20 12:43 ` [PATCH v3 08/18] arm64: Move documentation of dcache_by_line_op Fuad Tabba
2021-05-20 14:17 ` Mark Rutland
2021-05-20 12:43 ` [PATCH v3 09/18] arm64: Fix comments to refer to correct function __flush_icache_range Fuad Tabba
2021-05-20 14:18 ` Mark Rutland
2021-05-20 12:43 ` [PATCH v3 10/18] arm64: __inval_dcache_area to take end parameter instead of size Fuad Tabba
2021-05-20 15:46 ` Mark Rutland
2021-05-20 12:43 ` [PATCH v3 11/18] arm64: dcache_by_line_op " Fuad Tabba
2021-05-20 15:48 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 12/18] arm64: __flush_dcache_area " Fuad Tabba
2021-05-20 16:06 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 13/18] arm64: __clean_dcache_area_poc " Fuad Tabba
2021-05-20 16:16 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 14/18] arm64: __clean_dcache_area_pop " Fuad Tabba
2021-05-20 16:19 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 15/18] arm64: __clean_dcache_area_pou " Fuad Tabba
2021-05-20 16:24 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 16/18] arm64: sync_icache_aliases " Fuad Tabba
2021-05-20 16:34 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 17/18] arm64: Fix cache maintenance function comments Fuad Tabba
2021-05-20 16:48 ` Mark Rutland
2021-05-20 12:44 ` [PATCH v3 18/18] arm64: Rename arm64-internal cache maintenance functions Fuad Tabba
2021-05-20 17:01 ` Mark Rutland
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210520141555.GJ17233@C02TD0UTHF1T.local \
--to=mark.rutland@arm.com \
--cc=alexandru.elisei@arm.com \
--cc=ardb@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=james.morse@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=maz@kernel.org \
--cc=robin.murphy@arm.com \
--cc=suzuki.poulose@arm.com \
--cc=tabba@google.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).