/* 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);
