Le 16/03/2020 à 13:36, Christophe Leroy a écrit :
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.le...@c-s.fr>
---
arch/powerpc/include/asm/fixmap.h | 4 ++++
arch/powerpc/kernel/setup_32.c | 2 +-
arch/powerpc/mm/pgtable_32.c | 16 ++++++++++++++++
3 files changed, 21 insertions(+), 1 deletion(-)
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 5b49b26eb154..3f1e1c0b328a 100644
--- a/arch/powerpc/kernel/setup_32.c
+++ b/arch/powerpc/kernel/setup_32.c
@@ -81,7 +81,7 @@ 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;
Sparse reports this as a variable size array. This is definitely not.
Gcc properly sees it is an 8k table (2 pages).
Christophe
+
+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);
Christophe
