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authorChristophe Leroy <christophe.leroy@csgroup.eu>2020-05-19 05:48:58 +0000
committerMichael Ellerman <mpe@ellerman.id.au>2020-05-26 22:22:19 +1000
commit925ac141d106b55acbe112a9272f970631a3c082 (patch)
treedd8af6d39c2dc563a235af298b36cb964105f2f2 /arch
parent4b19f96a81bceaf0bcf44d79c0855c61158065ec (diff)
powerpc/mm: Allocate static page tables for fixmap
Allocate static page tables for the fixmap area. This allows setting mappings through page tables before memblock is ready. That's needed to use early_ioremap() early and to use standard page mappings with fixmap. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/4f4b1412d34de6801b8e925cb88fc69d056ff536.1589866984.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/fixmap.h4
-rw-r--r--arch/powerpc/kernel/setup_32.c2
-rw-r--r--arch/powerpc/mm/pgtable_32.c16
3 files changed, 21 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/fixmap.h b/arch/powerpc/include/asm/fixmap.h
index 2ef155a3c821..ccbe2e83c950 100644
--- a/arch/powerpc/include/asm/fixmap.h
+++ b/arch/powerpc/include/asm/fixmap.h
@@ -86,6 +86,10 @@ enum fixed_addresses {
#define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE)
+#define FIXMAP_ALIGNED_SIZE (ALIGN(FIXADDR_TOP, PGDIR_SIZE) - \
+ ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE))
+#define FIXMAP_PTE_SIZE (FIXMAP_ALIGNED_SIZE / PGDIR_SIZE * PTE_TABLE_SIZE)
+
#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
#define FIXMAP_PAGE_IO PAGE_KERNEL_NCG
diff --git a/arch/powerpc/kernel/setup_32.c b/arch/powerpc/kernel/setup_32.c
index 15f0a7c84944..d642e42eabb1 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -80,7 +80,7 @@ notrace void __init machine_init(u64 dt_ptr)
/* Configure static keys first, now that we're relocated. */
setup_feature_keys();
- early_ioremap_setup();
+ early_ioremap_init();
/* Enable early debugging if any specified (see udbg.h) */
udbg_early_init();
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index f62de06e3d07..9934659cb871 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -29,11 +29,27 @@
#include <asm/fixmap.h>
#include <asm/setup.h>
#include <asm/sections.h>
+#include <asm/early_ioremap.h>
#include <mm/mmu_decl.h>
extern char etext[], _stext[], _sinittext[], _einittext[];
+static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data;
+
+notrace void __init early_ioremap_init(void)
+{
+ unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE);
+ pte_t *ptep = (pte_t *)early_fixmap_pagetable;
+ pmd_t *pmdp = pmd_ptr_k(addr);
+
+ for (; (s32)(FIXADDR_TOP - addr) > 0;
+ addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++)
+ pmd_populate_kernel(&init_mm, pmdp, ptep);
+
+ early_ioremap_setup();
+}
+
static void __init *early_alloc_pgtable(unsigned long size)
{
void *ptr = memblock_alloc(size, size);