[PATCH 2/3] powerpc: Define swapper_pg_dir[] in C

From: Christophe Leroy
Date: Mon Jun 07 2021 - 06:56:18 EST


Don't duplicate swapper_pg_dir[] in each platform's head.S

Define it in mm/pgtable.c

Define MAX_PTRS_PER_PGD because on book3s/64 PTRS_PER_PGD is
not a constant.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 3 +++
arch/powerpc/include/asm/pgtable.h | 4 ++++
arch/powerpc/kernel/asm-offsets.c | 5 -----
arch/powerpc/kernel/head_40x.S | 11 -----------
arch/powerpc/kernel/head_44x.S | 17 +----------------
arch/powerpc/kernel/head_64.S | 15 ---------------
arch/powerpc/kernel/head_8xx.S | 12 ------------
arch/powerpc/kernel/head_book3s_32.S | 11 -----------
arch/powerpc/kernel/head_fsl_booke.S | 12 ------------
arch/powerpc/mm/pgtable.c | 2 ++
10 files changed, 10 insertions(+), 82 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index a666d561b44d..4d9941b2fe51 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -232,6 +232,9 @@ extern unsigned long __pmd_frag_size_shift;
#define PTRS_PER_PUD (1 << PUD_INDEX_SIZE)
#define PTRS_PER_PGD (1 << PGD_INDEX_SIZE)

+#define MAX_PTRS_PER_PGD (1 << (H_PGD_INDEX_SIZE > RADIX_PGD_INDEX_SIZE ? \
+ H_PGD_INDEX_SIZE : RADIX_PGD_INDEX_SIZE))
+
/* PMD_SHIFT determines what a second-level page table entry can map */
#define PMD_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE)
#define PMD_SIZE (1UL << PMD_SHIFT)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index c6a676714f04..b9c8641654f4 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -41,6 +41,10 @@ struct mm_struct;

#ifndef __ASSEMBLY__

+#ifndef MAX_PTRS_PER_PGD
+#define MAX_PTRS_PER_PGD PTRS_PER_PGD
+#endif
+
/* Keep these as a macros to avoid include dependency mess */
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 0480f4006e0c..f1b6ff14c8a0 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -361,11 +361,6 @@ int main(void)
DEFINE(BUG_ENTRY_SIZE, sizeof(struct bug_entry));
#endif

-#ifdef CONFIG_PPC_BOOK3S_64
- DEFINE(PGD_TABLE_SIZE, (sizeof(pgd_t) << max(RADIX_PGD_INDEX_SIZE, H_PGD_INDEX_SIZE)));
-#else
- DEFINE(PGD_TABLE_SIZE, PGD_TABLE_SIZE);
-#endif
DEFINE(PTE_SIZE, sizeof(pte_t));

#ifdef CONFIG_KVM
diff --git a/arch/powerpc/kernel/head_40x.S b/arch/powerpc/kernel/head_40x.S
index 92b6c7356161..7d72ee5ab387 100644
--- a/arch/powerpc/kernel/head_40x.S
+++ b/arch/powerpc/kernel/head_40x.S
@@ -701,14 +701,3 @@ _GLOBAL(abort)
mfspr r13,SPRN_DBCR0
oris r13,r13,DBCR0_RST_SYSTEM@h
mtspr SPRN_DBCR0,r13
-
-/* We put a few things here that have to be page-aligned. This stuff
- * goes at the beginning of the data segment, which is page-aligned.
- */
- .data
- .align 12
- .globl sdata
-sdata:
- .globl swapper_pg_dir
-swapper_pg_dir:
- .space PGD_TABLE_SIZE
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index e037eb615757..ddc978a2d381 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -1233,23 +1233,8 @@ head_start_common:
isync
blr

-/*
- * We put a few things here that have to be page-aligned. This stuff
- * goes at the beginning of the data segment, which is page-aligned.
- */
- .data
- .align PAGE_SHIFT
- .globl sdata
-sdata:
-
-/*
- * To support >32-bit physical addresses, we use an 8KB pgdir.
- */
- .globl swapper_pg_dir
-swapper_pg_dir:
- .space PGD_TABLE_SIZE
-
#ifdef CONFIG_SMP
+ .data
.align 12
temp_boot_stack:
.space 1024
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 730838c7ca39..79f2d1e61abd 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -997,18 +997,3 @@ start_here_common:
0: trap
EMIT_BUG_ENTRY 0b, __FILE__, __LINE__, 0
.previous
-
-/*
- * We put a few things here that have to be page-aligned.
- * This stuff goes at the beginning of the bss, which is page-aligned.
- */
- .section ".bss"
-/*
- * pgd dir should be aligned to PGD_TABLE_SIZE which is 64K.
- * We will need to find a better way to fix this
- */
- .align 16
-
- .globl swapper_pg_dir
-swapper_pg_dir:
- .space PGD_TABLE_SIZE
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 5ce42dfac061..9bdb95f5694f 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -786,15 +786,3 @@ _GLOBAL(mmu_pin_tlb)
mtspr SPRN_SRR1, r10
mtspr SPRN_SRR0, r11
rfi
-
-/*
- * We put a few things here that have to be page-aligned.
- * This stuff goes at the beginning of the data segment,
- * which is page-aligned.
- */
- .data
- .globl sdata
-sdata:
- .globl swapper_pg_dir
-swapper_pg_dir:
- .space PGD_TABLE_SIZE
diff --git a/arch/powerpc/kernel/head_book3s_32.S b/arch/powerpc/kernel/head_book3s_32.S
index 79c744afc6b6..689c9d37f193 100644
--- a/arch/powerpc/kernel/head_book3s_32.S
+++ b/arch/powerpc/kernel/head_book3s_32.S
@@ -1266,18 +1266,7 @@ setup_usbgecko_bat:
blr
#endif

-/*
- * We put a few things here that have to be page-aligned.
- * This stuff goes at the beginning of the data segment,
- * which is page-aligned.
- */
.data
- .globl sdata
-sdata:
- .globl swapper_pg_dir
-swapper_pg_dir:
- .space PGD_TABLE_SIZE
-
/* Room for two PTE pointers, usually the kernel and current user pointers
* to their respective root page table.
*/
diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index f33bc5a8e73e..0f9642f36b49 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1212,15 +1212,3 @@ _GLOBAL(restore_to_as0)
*/
3: mr r3,r5
bl _start
-
-/*
- * We put a few things here that have to be page-aligned. This stuff
- * goes at the beginning of the data segment, which is page-aligned.
- */
- .data
- .align 12
- .globl sdata
-sdata:
- .globl swapper_pg_dir
-swapper_pg_dir:
- .space PGD_TABLE_SIZE
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 354611940118..1707ab580ee2 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -28,6 +28,8 @@
#include <asm/hugetlb.h>
#include <asm/pte-walk.h>

+pgd_t swapper_pg_dir[MAX_PTRS_PER_PGD] __page_aligned_bss;
+
static inline int is_exec_fault(void)
{
return current->thread.regs && TRAP(current->thread.regs) == 0x400;
--
2.25.0