From 925ac141d106b55acbe112a9272f970631a3c082 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 19 May 2020 05:48:58 +0000 Subject: [PATCH] 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 Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/4f4b1412d34de6801b8e925cb88fc69d056ff536.1589866984.git.christophe.leroy@csgroup.eu --- 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 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 #include #include +#include #include 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); -- 2.11.0