From 4a6d8cf90017019f3b2829b38157cd1a74c64856 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 26 Apr 2019 15:58:06 +0000 Subject: [PATCH] powerpc/mm: don't use pte_alloc_kernel() until slab is available on PPC32 In the same way as PPC64, implement early allocation functions and avoid calling pte_alloc_kernel() before slab is available. Reviewed-by: Aneesh Kumar K.V Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman --- arch/powerpc/mm/pgtable_32.c | 34 ++++++++++++++++++++++++++++------ 1 file changed, 28 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c index c9cdbb84d31f..e54b612cbc98 100644 --- a/arch/powerpc/mm/pgtable_32.c +++ b/arch/powerpc/mm/pgtable_32.c @@ -43,11 +43,8 @@ EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ extern char etext[], _stext[], _sinittext[], _einittext[]; -__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm) +pte_t *pte_alloc_one_kernel(struct mm_struct *mm) { - if (!slab_is_available()) - return memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE); - return (pte_t *)pte_fragment_alloc(mm, 1); } @@ -205,7 +202,29 @@ void iounmap(volatile void __iomem *addr) } EXPORT_SYMBOL(iounmap); -int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot) +static void __init *early_alloc_pgtable(unsigned long size) +{ + void *ptr = memblock_alloc(size, size); + + if (!ptr) + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", + __func__, size, size); + + return ptr; +} + +static pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va) +{ + if (pmd_none(*pmdp)) { + pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE); + + pmd_populate_kernel(&init_mm, pmdp, ptep); + } + return pte_offset_kernel(pmdp, va); +} + + +int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot) { pmd_t *pd; pte_t *pg; @@ -214,7 +233,10 @@ int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot) /* Use upper 10 bits of VA to index the first level map */ pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); /* Use middle 10 bits of VA to index the second-level map */ - pg = pte_alloc_kernel(pd, va); + if (likely(slab_is_available())) + pg = pte_alloc_kernel(pd, va); + else + pg = early_pte_alloc_kernel(pd, va); if (pg != 0) { err = 0; /* The PTE should never be already set nor present in the