[PATCH v3 4/5] x86/kernel: Move page table macros to header

Jason Andryuk posted 5 patches 2 months, 4 weeks ago
There is a newer version of this series
[PATCH v3 4/5] x86/kernel: Move page table macros to header
Posted by Jason Andryuk 2 months, 4 weeks ago
The PVH entry point will need an additional set of prebuild page tables.
Move the macros and defines to pgtable_64.h, so they can be re-used.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
---
v3:
Add Juergen's R-b

v2:
Use existing pgtable_64.h
s/-/ - / in pud_index()
Did not add Juergen's R-b in case the header movement matters
---
 arch/x86/include/asm/pgtable_64.h | 23 ++++++++++++++++++++++-
 arch/x86/kernel/head_64.S         | 20 --------------------
 2 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 3c4407271d08..72912b8edfdf 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -271,5 +271,26 @@ static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
 
 #include <asm/pgtable-invert.h>
 
-#endif /* !__ASSEMBLY__ */
+#else /* __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 /* _ASM_X86_PGTABLE_64_H */
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 330922b328bf..16752b8dfa89 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -32,13 +32,6 @@
  * 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)
 
 	__HEAD
 	.code64
@@ -577,9 +570,6 @@ 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_MITIGATION_PAGE_TABLE_ISOLATION
 /*
  * Each PGD needs to be 8k long and 8k aligned.  We do not
@@ -601,14 +591,6 @@ 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
 
@@ -708,8 +690,6 @@ SYM_DATA_START_PAGE_ALIGNED(level1_fixmap_pgt)
 	.endr
 SYM_DATA_END(level1_fixmap_pgt)
 
-#undef PMDS
-
 	.data
 	.align 16
 
-- 
2.34.1
Re: [PATCH v3 4/5] x86/kernel: Move page table macros to header
Posted by Dave Hansen 1 month, 3 weeks ago
On 8/23/24 12:36, Jason Andryuk wrote:
> The PVH entry point will need an additional set of prebuild page tables.
> Move the macros and defines to pgtable_64.h, so they can be re-used.
> 
> Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
> Reviewed-by: Juergen Gross <jgross@suse.com>

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>