diff options
Diffstat (limited to 'arch/powerpc/mm/tlb_64.c')
| -rw-r--r-- | arch/powerpc/mm/tlb_64.c | 57 |
1 files changed, 56 insertions, 1 deletions
diff --git a/arch/powerpc/mm/tlb_64.c b/arch/powerpc/mm/tlb_64.c index 2bfc4d7e1aa2..cbd34fc813ee 100644 --- a/arch/powerpc/mm/tlb_64.c +++ b/arch/powerpc/mm/tlb_64.c @@ -8,7 +8,6 @@ * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras - * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds @@ -239,3 +238,59 @@ void pte_free_finish(void) pte_free_submit(*batchp); *batchp = NULL; } + +/** + * __flush_hash_table_range - Flush all HPTEs for a given address range + * from the hash table (and the TLB). But keeps + * the linux PTEs intact. + * + * @mm : mm_struct of the target address space (generally init_mm) + * @start : starting address + * @end : ending address (not included in the flush) + * + * This function is mostly to be used by some IO hotplug code in order + * to remove all hash entries from a given address range used to map IO + * space on a removed PCI-PCI bidge without tearing down the full mapping + * since 64K pages may overlap with other bridges when using 64K pages + * with 4K HW pages on IO space. + * + * Because of that usage pattern, it's only available with CONFIG_HOTPLUG + * and is implemented for small size rather than speed. + */ +#ifdef CONFIG_HOTPLUG + +void __flush_hash_table_range(struct mm_struct *mm, unsigned long start, + unsigned long end) +{ + unsigned long flags; + + start = _ALIGN_DOWN(start, PAGE_SIZE); + end = _ALIGN_UP(end, PAGE_SIZE); + + BUG_ON(!mm->pgd); + + /* Note: Normally, we should only ever use a batch within a + * PTE locked section. This violates the rule, but will work + * since we don't actually modify the PTEs, we just flush the + * hash while leaving the PTEs intact (including their reference + * to being hashed). This is not the most performance oriented + * way to do things but is fine for our needs here. + */ + local_irq_save(flags); + arch_enter_lazy_mmu_mode(); + for (; start < end; start += PAGE_SIZE) { + pte_t *ptep = find_linux_pte(mm->pgd, start); + unsigned long pte; + + if (ptep == NULL) + continue; + pte = pte_val(*ptep); + if (!(pte & _PAGE_HASHPTE)) + continue; + hpte_need_flush(mm, start, ptep, pte, 0); + } + arch_leave_lazy_mmu_mode(); + local_irq_restore(flags); +} + +#endif /* CONFIG_HOTPLUG */ |