linux-kernel - [PATCH 2/2] x86/purgatory: Omit use of bin2c

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Date:   Thu, 16 Jun 2022 16:24:07 +0900
From:   Masahiro Yamada <masahiroy@...nel.org>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
        "H . Peter Anvin" <hpa@...or.com>
Cc:     linux-kernel@...r.kernel.org,
        Masahiro Yamada <masahiroy@...nel.org>
Subject: [PATCH 2/2] x86/purgatory: Omit use of bin2c

The .incbin assembler directive is much faster than bin2c + $(CC).

Do similar refactoring as in commit 4c0f032d4963 ("s390/purgatory:
Omit use of bin2c").

Please note the .quad directive matches to size_t in C (both 8 byte)
because the purgatory is compiled only for the 64-bit kernel.
(KEXEC_FILE depends on X86_64).

Signed-off-by: Masahiro Yamada <masahiroy@...nel.org>
---

 arch/x86/.gitignore                  |  2 --
 arch/x86/Kconfig                     |  1 -
 arch/x86/purgatory/Makefile          |  8 +-------
 arch/x86/purgatory/kexec-purgatory.S | 14 ++++++++++++++
 scripts/remove-stale-files           |  2 ++
 5 files changed, 17 insertions(+), 10 deletions(-)
 create mode 100644 arch/x86/purgatory/kexec-purgatory.S

diff --git a/arch/x86/.gitignore b/arch/x86/.gitignore
index 677111acbaa3..f2e1d6c347fb 100644
--- a/arch/x86/.gitignore
+++ b/arch/x86/.gitignore
@@ -3,6 +3,4 @@ boot/compressed/vmlinux
 tools/test_get_len
 tools/insn_sanity
 tools/insn_decoder_test
-purgatory/kexec-purgatory.c
 purgatory/purgatory.ro
-
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index be0b95e51df6..2c1d37cd479f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2032,7 +2032,6 @@ config KEXEC
 config KEXEC_FILE
 	bool "kexec file based system call"
 	select KEXEC_CORE
-	select BUILD_BIN2C
 	depends on X86_64
 	depends on CRYPTO=y
 	depends on CRYPTO_SHA256=y
diff --git a/arch/x86/purgatory/Makefile b/arch/x86/purgatory/Makefile
index 248b009c4061..31c634a22818 100644
--- a/arch/x86/purgatory/Makefile
+++ b/arch/x86/purgatory/Makefile
@@ -73,12 +73,6 @@ $(obj)/purgatory.ro: $(PURGATORY_OBJS) FORCE
 $(obj)/purgatory.chk: $(obj)/purgatory.ro FORCE
 		$(call if_changed,ld)
 
-targets += kexec-purgatory.c
-
-quiet_cmd_bin2c = BIN2C   $@
-      cmd_bin2c = $(objtree)/scripts/bin2c kexec_purgatory < $< > $@
-
-$(obj)/kexec-purgatory.c: $(obj)/purgatory.ro $(obj)/purgatory.chk FORCE
-	$(call if_changed,bin2c)
+$(obj)/kexec-purgatory.o: $(obj)/purgatory.ro $(obj)/purgatory.chk
 
 obj-y += kexec-purgatory.o
diff --git a/arch/x86/purgatory/kexec-purgatory.S b/arch/x86/purgatory/kexec-purgatory.S
new file mode 100644
index 000000000000..1a1abf6268bc
--- /dev/null
+++ b/arch/x86/purgatory/kexec-purgatory.S
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+	.section .rodata, "a"
+
+	.align	8
+kexec_purgatory:
+	.globl	kexec_purgatory
+	.incbin	"arch/x86/purgatory/purgatory.ro"
+.Lkexec_purgatroy_end:
+
+	.align	8
+kexec_purgatory_size:
+	.globl	kexec_purgatory_size
+	.quad	.Lkexec_purgatroy_end - kexec_purgatory
diff --git a/scripts/remove-stale-files b/scripts/remove-stale-files
index 7adab4618035..379e86c71bed 100755
--- a/scripts/remove-stale-files
+++ b/scripts/remove-stale-files
@@ -41,3 +41,5 @@ if [ -n "${building_out_of_srctree}" ]; then
 fi
 
 rm -f scripts/extract-cert
+
+rm -f arch/x86/purgatory/kexec-purgatory.c
-- 
2.32.0