diff options
Diffstat (limited to 'arch/powerpc/mm/pgtable-hash64.c')
| -rw-r--r-- | arch/powerpc/mm/pgtable-hash64.c | 115 |
1 files changed, 114 insertions, 1 deletions
diff --git a/arch/powerpc/mm/pgtable-hash64.c b/arch/powerpc/mm/pgtable-hash64.c index 8b85a14b08ea..188b4107584d 100644 --- a/arch/powerpc/mm/pgtable-hash64.c +++ b/arch/powerpc/mm/pgtable-hash64.c @@ -11,8 +11,12 @@ #include <linux/sched.h> #include <linux/mm_types.h> +#include <linux/mm.h> #include <asm/pgalloc.h> +#include <asm/pgtable.h> +#include <asm/sections.h> +#include <asm/mmu.h> #include <asm/tlb.h> #include "mmu_decl.h" @@ -22,6 +26,81 @@ #ifdef CONFIG_SPARSEMEM_VMEMMAP /* + * vmemmap is the starting address of the virtual address space where + * struct pages are allocated for all possible PFNs present on the system + * including holes and bad memory (hence sparse). These virtual struct + * pages are stored in sequence in this virtual address space irrespective + * of the fact whether the corresponding PFN is valid or not. This achieves + * constant relationship between address of struct page and its PFN. + * + * During boot or memory hotplug operation when a new memory section is + * added, physical memory allocation (including hash table bolting) will + * be performed for the set of struct pages which are part of the memory + * section. This saves memory by not allocating struct pages for PFNs + * which are not valid. + * + * ---------------------------------------------- + * | PHYSICAL ALLOCATION OF VIRTUAL STRUCT PAGES| + * ---------------------------------------------- + * + * f000000000000000 c000000000000000 + * vmemmap +--------------+ +--------------+ + * + | page struct | +--------------> | page struct | + * | +--------------+ +--------------+ + * | | page struct | +--------------> | page struct | + * | +--------------+ | +--------------+ + * | | page struct | + +------> | page struct | + * | +--------------+ | +--------------+ + * | | page struct | | +--> | page struct | + * | +--------------+ | | +--------------+ + * | | page struct | | | + * | +--------------+ | | + * | | page struct | | | + * | +--------------+ | | + * | | page struct | | | + * | +--------------+ | | + * | | page struct | | | + * | +--------------+ | | + * | | page struct | +-------+ | + * | +--------------+ | + * | | page struct | +-----------+ + * | +--------------+ + * | | page struct | No mapping + * | +--------------+ + * | | page struct | No mapping + * v +--------------+ + * + * ----------------------------------------- + * | RELATION BETWEEN STRUCT PAGES AND PFNS| + * ----------------------------------------- + * + * vmemmap +--------------+ +---------------+ + * + | page struct | +-------------> | PFN | + * | +--------------+ +---------------+ + * | | page struct | +-------------> | PFN | + * | +--------------+ +---------------+ + * | | page struct | +-------------> | PFN | + * | +--------------+ +---------------+ + * | | page struct | +-------------> | PFN | + * | +--------------+ +---------------+ + * | | | + * | +--------------+ + * | | | + * | +--------------+ + * | | | + * | +--------------+ +---------------+ + * | | page struct | +-------------> | PFN | + * | +--------------+ +---------------+ + * | | | + * | +--------------+ + * | | | + * | +--------------+ +---------------+ + * | | page struct | +-------------> | PFN | + * | +--------------+ +---------------+ + * | | page struct | +-------------> | PFN | + * v +--------------+ +---------------+ + */ +/* * On hash-based CPUs, the vmemmap is bolted in the hash table. * */ @@ -109,7 +188,7 @@ unsigned long hash__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr unsigned long old; #ifdef CONFIG_DEBUG_VM - WARN_ON(!pmd_trans_huge(*pmdp)); + WARN_ON(!hash__pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp)); assert_spin_locked(&mm->page_table_lock); #endif @@ -141,6 +220,7 @@ pmd_t hash__pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long addres VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(pmd_trans_huge(*pmdp)); + VM_BUG_ON(pmd_devmap(*pmdp)); pmd = *pmdp; pmd_clear(pmdp); @@ -221,6 +301,7 @@ void hash__pmdp_huge_split_prepare(struct vm_area_struct *vma, { VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(REGION_ID(address) != USER_REGION_ID); + VM_BUG_ON(pmd_devmap(*pmdp)); /* * We can't mark the pmd none here, because that will cause a race @@ -342,3 +423,35 @@ int hash__has_transparent_hugepage(void) return 1; } #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ + +#ifdef CONFIG_STRICT_KERNEL_RWX +void hash__mark_rodata_ro(void) +{ + unsigned long start = (unsigned long)_stext; + unsigned long end = (unsigned long)__init_begin; + unsigned long idx; + unsigned int step, shift; + unsigned long newpp = PP_RXXX; + + shift = mmu_psize_defs[mmu_linear_psize].shift; + step = 1 << shift; + + start = ((start + step - 1) >> shift) << shift; + end = (end >> shift) << shift; + + pr_devel("marking ro start %lx, end %lx, step %x\n", + start, end, step); + + if (start == end) { + pr_warn("could not set rodata ro, relocate the start" + " of the kernel to a 0x%x boundary\n", step); + return; + } + + for (idx = start; idx < end; idx += step) + /* Not sure if we can do much with the return value */ + mmu_hash_ops.hpte_updateboltedpp(newpp, idx, mmu_linear_psize, + mmu_kernel_ssize); + +} +#endif |