From: Kai Huang <kai.huang@intel.com>
To: linux-kernel@vger.kernel.org
Cc: dave.hansen@linux.intel.com, kirill.shutemov@linux.intel.com,
peterz@infradead.org, hpa@zytor.com, konrad.wilk@oracle.com,
rostedt@goodmis.org, jpoimboe@kernel.org,
Kai Huang <kai.huang@intel.com>
Subject: [PATCH] x86/kexec: Add a comment to relocate_kernel() for better readability
Date: Wed, 7 Jun 2023 22:39:10 +1200 [thread overview]
Message-ID: <20230607103910.407779-1-kai.huang@intel.com> (raw)
The reason to save %rcx to %r11 before calling swap_pages isn't that
obvious w/o looking into the swap_pages itself. Add a comment to
improve the readability.
Signed-off-by: Kai Huang <kai.huang@intel.com>
---
arch/x86/kernel/relocate_kernel_64.S | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S
index 56cab1bb25f5..97deae3c5e6c 100644
--- a/arch/x86/kernel/relocate_kernel_64.S
+++ b/arch/x86/kernel/relocate_kernel_64.S
@@ -169,6 +169,10 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped)
wbinvd
1:
+ /*
+ * Save the preserve_context to %r11 as
+ * swap_pages clobbers %rcx.
+ */
movq %rcx, %r11
call swap_pages
base-commit: 409bf2895d71bb68bc5b8589036e5ed1ca30bada
--
2.40.1
next reply other threads:[~2023-06-07 10:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-07 10:39 Kai Huang [this message]
2023-06-07 11:19 ` kirill.shutemov
2023-06-08 4:41 ` Huang, Kai
2023-06-08 11:25 ` kirill.shutemov
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