/* Invalidate icache when dcache doesn't need invalidation as it's in * write-through mode * * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #include <linux/module.h> #include <linux/mm.h> #include <asm/cacheflush.h> #include <asm/smp.h> #include "cache-smp.h" /** * flush_icache_page_range - Flush dcache and invalidate icache for part of a * single page * @start: The starting virtual address of the page part. * @end: The ending virtual address of the page part. * * Invalidate the icache for part of a single page, as determined by the * virtual addresses given. The page must be in the paged area. The dcache is * not flushed as the cache must be in write-through mode to get here. */ static void flush_icache_page_range(unsigned long start, unsigned long end) { unsigned long addr, size, off; struct page *page; pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *ppte, pte; /* work out how much of the page to flush */ off = start & ~PAGE_MASK; size = end - start; /* get the physical address the page is mapped to from the page * tables */ pgd = pgd_offset(current->mm, start); if (!pgd || !pgd_val(*pgd)) return; pud = pud_offset(pgd, start); if (!pud || !pud_val(*pud)) return; pmd = pmd_offset(pud, start); if (!pmd || !pmd_val(*pmd)) return; ppte = pte_offset_map(pmd, start); if (!ppte) return; pte = *ppte; pte_unmap(ppte); if (pte_none(pte)) return; page = pte_page(pte); if (!page) return; addr = page_to_phys(page); /* invalidate the icache coverage on that region */ mn10300_local_icache_inv_range2(addr + off, size); smp_cache_call(SMP_ICACHE_INV_RANGE, start, end); } /** * flush_icache_range - Globally flush dcache and invalidate icache for region * @start: The starting virtual address of the region. * @end: The ending virtual address of the region. * * This is used by the kernel to globally flush some code it has just written * from the dcache back to RAM and then to globally invalidate the icache over * that region so that that code can be run on all CPUs in the system. */ void flush_icache_range(unsigned long start, unsigned long end) { unsigned long start_page, end_page; unsigned long flags; flags = smp_lock_cache(); if (end > 0x80000000UL) { /* addresses above 0xa0000000 do not go through the cache */ if (end > 0xa0000000UL) { end = 0xa0000000UL; if (start >= end) goto done; } /* kernel addresses between 0x80000000 and 0x9fffffff do not * require page tables, so we just map such addresses * directly */ start_page = (start >= 0x80000000UL) ? start : 0x80000000UL; mn10300_icache_inv_range(start_page, end); smp_cache_call(SMP_ICACHE_INV_RANGE, start, end); if (start_page == start) goto done; end = start_page; } start_page = start & PAGE_MASK; end_page = (end - 1) & PAGE_MASK; if (start_page == end_page) { /* the first and last bytes are on the same page */ flush_icache_page_range(start, end); } else if (start_page + 1 == end_page) { /* split over two virtually contiguous pages */ flush_icache_page_range(start, end_page); flush_icache_page_range(end_page, end); } else { /* more than 2 pages; just flush the entire cache */ mn10300_local_icache_inv(); smp_cache_call(SMP_ICACHE_INV, 0, 0); } done: smp_unlock_cache(flags); } EXPORT_SYMBOL(flush_icache_range);