[PATCH 4/5] x86/kernel: Move page table macros to new header

[Jason Andryuk]

The PVH entry point will need an additional set of prebuild page tables.
Move the macros and defines to a new header so they can be re-used.

Signed-off-by: Jason Andryuk <jason.andryuk@xxxxxxx>
---
checkpatch.pl gives an error: "ERROR: Macros with multiple statements
should be enclosed in a do - while loop" about the moved PMDS macro.
But PMDS is an assembler macro, so its not applicable.
---
 arch/x86/kernel/head_64.S            | 22 ++--------------------
 arch/x86/kernel/pgtable_64_helpers.h | 28 ++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 20 deletions(-)
 create mode 100644 arch/x86/kernel/pgtable_64_helpers.h

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index d4918d03efb4..4b036f3220f2 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -27,17 +27,12 @@
 #include <asm/fixmap.h>
 #include <asm/smp.h>
 
+#include "pgtable_64_helpers.h"
+
 /*
  * We are not able to switch in one step to the final KERNEL ADDRESS SPACE
  * because we need identity-mapped pages.
  */
-#define l4_index(x)	(((x) >> 39) & 511)
-#define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
-
-L4_PAGE_OFFSET = l4_index(__PAGE_OFFSET_BASE_L4)
-L4_START_KERNEL = l4_index(__START_KERNEL_map)
-
-L3_START_KERNEL = pud_index(__START_KERNEL_map)
 
 	.text
 	__HEAD
@@ -619,9 +614,6 @@ SYM_CODE_START_NOALIGN(vc_no_ghcb)
 SYM_CODE_END(vc_no_ghcb)
 #endif
 
-#define SYM_DATA_START_PAGE_ALIGNED(name)			\
-	SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE)
-
 #ifdef CONFIG_PAGE_TABLE_ISOLATION
 /*
  * Each PGD needs to be 8k long and 8k aligned.  We do not
@@ -643,14 +635,6 @@ SYM_CODE_END(vc_no_ghcb)
 #define PTI_USER_PGD_FILL	0
 #endif
 
-/* Automate the creation of 1 to 1 mapping pmd entries */
-#define PMDS(START, PERM, COUNT)			\
-	i = 0 ;						\
-	.rept (COUNT) ;					\
-	.quad	(START) + (i << PMD_SHIFT) + (PERM) ;	\
-	i = i + 1 ;					\
-	.endr
-
 	__INITDATA
 	.balign 4
 
@@ -749,8 +733,6 @@ SYM_DATA_START_PAGE_ALIGNED(level1_fixmap_pgt)
 	.endr
 SYM_DATA_END(level1_fixmap_pgt)
 
-#undef PMDS
-
 	.data
 	.align 16
 
diff --git a/arch/x86/kernel/pgtable_64_helpers.h b/arch/x86/kernel/pgtable_64_helpers.h
new file mode 100644
index 000000000000..0ae87d768ce2
--- /dev/null
+++ b/arch/x86/kernel/pgtable_64_helpers.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PGTABLES_64_H__
+#define __PGTABLES_64_H__
+
+#ifdef __ASSEMBLY__
+
+#define l4_index(x)	(((x) >> 39) & 511)
+#define pud_index(x)	(((x) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
+
+L4_PAGE_OFFSET = l4_index(__PAGE_OFFSET_BASE_L4)
+L4_START_KERNEL = l4_index(__START_KERNEL_map)
+
+L3_START_KERNEL = pud_index(__START_KERNEL_map)
+
+#define SYM_DATA_START_PAGE_ALIGNED(name)			\
+	SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE)
+
+/* Automate the creation of 1 to 1 mapping pmd entries */
+#define PMDS(START, PERM, COUNT)			\
+	i = 0 ;						\
+	.rept (COUNT) ;					\
+	.quad	(START) + (i << PMD_SHIFT) + (PERM) ;	\
+	i = i + 1 ;					\
+	.endr
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __PGTABLES_64_H__ */
-- 
2.44.0