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

Jason Andryuk
2024-04-10T19:49:13Z

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@amd.com>
---
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