diff options
Diffstat (limited to 'arch/mn10300/mm/cache-inv-icache.c')
| -rw-r--r-- | arch/mn10300/mm/cache-inv-icache.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/arch/mn10300/mm/cache-inv-icache.c b/arch/mn10300/mm/cache-inv-icache.c new file mode 100644 index 00000000000..4a3f7afcfe5 --- /dev/null +++ b/arch/mn10300/mm/cache-inv-icache.c @@ -0,0 +1,119 @@ +/* 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> + +/** + * 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_icache_inv_range2(addr + off, size); +} + +/** + * 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; + + if (end > 0x80000000UL) { + /* addresses above 0xa0000000 do not go through the cache */ + if (end > 0xa0000000UL) { + end = 0xa0000000UL; + if (start >= end) + return; + } + + /* 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_dcache_flush_range(start_page, end); + mn10300_icache_inv_range(start_page, end); + if (start_page == start) + return; + end = start_page; + } + + start_page = start & PAGE_MASK; + end_page = end & 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_icache_inv(); + } +} +EXPORT_SYMBOL(flush_icache_range); |