linux-sg2042/arch/sh/mm/cache-sh2a.c

/*
 * arch/sh/mm/cache-sh2a.c
 *
 * Copyright (C) 2008 Yoshinori Sato
 *
 * Released under the terms of the GNU GPL v2.0.
 */

#include <linux/init.h>
#include <linux/mm.h>

#include <asm/cache.h>
#include <asm/addrspace.h>
#include <asm/processor.h>
#include <asm/cacheflush.h>
#include <asm/io.h>

/*
 * The maximum number of pages we support up to when doing ranged dcache
 * flushing. Anything exceeding this will simply flush the dcache in its
 * entirety.
 */
#define MAX_OCACHE_PAGES	32
#define MAX_ICACHE_PAGES	32

#ifdef CONFIG_CACHE_WRITEBACK
static void sh2a_flush_oc_line(unsigned long v, int way)
{
	unsigned long addr = (v & 0x000007f0) | (way << 11);
	unsigned long data;

	data = __raw_readl(CACHE_OC_ADDRESS_ARRAY | addr);
	if ((data & CACHE_PHYSADDR_MASK) == (v & CACHE_PHYSADDR_MASK)) {
		data &= ~SH_CACHE_UPDATED;
		__raw_writel(data, CACHE_OC_ADDRESS_ARRAY | addr);
	}
}
#endif

static void sh2a_invalidate_line(unsigned long cache_addr, unsigned long v)
{
	/* Set associative bit to hit all ways */
	unsigned long addr = (v & 0x000007f0) | SH_CACHE_ASSOC;
	__raw_writel((addr & CACHE_PHYSADDR_MASK), cache_addr | addr);
}

/*
 * Write back the dirty D-caches, but not invalidate them.
 */
static void sh2a__flush_wback_region(void *start, int size)
{
#ifdef CONFIG_CACHE_WRITEBACK
	unsigned long v;
	unsigned long begin, end;
	unsigned long flags;
	int nr_ways;

	begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
	end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
		& ~(L1_CACHE_BYTES-1);
	nr_ways = current_cpu_data.dcache.ways;

	local_irq_save(flags);
	jump_to_uncached();

	/* If there are too many pages then flush the entire cache */
	if (((end - begin) >> PAGE_SHIFT) >= MAX_OCACHE_PAGES) {
		begin = CACHE_OC_ADDRESS_ARRAY;
		end = begin + (nr_ways * current_cpu_data.dcache.way_size);

		for (v = begin; v < end; v += L1_CACHE_BYTES) {
			unsigned long data = __raw_readl(v);
			if (data & SH_CACHE_UPDATED)
				__raw_writel(data & ~SH_CACHE_UPDATED, v);
		}
	} else {
		int way;
		for (way = 0; way < nr_ways; way++) {
			for (v = begin; v < end; v += L1_CACHE_BYTES)
				sh2a_flush_oc_line(v, way);
		}
	}

	back_to_cached();
	local_irq_restore(flags);
#endif
}

/*
 * Write back the dirty D-caches and invalidate them.
 */
static void sh2a__flush_purge_region(void *start, int size)
{
	unsigned long v;
	unsigned long begin, end;
	unsigned long flags;

	begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
	end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
		& ~(L1_CACHE_BYTES-1);

	local_irq_save(flags);
	jump_to_uncached();

	for (v = begin; v < end; v+=L1_CACHE_BYTES) {
#ifdef CONFIG_CACHE_WRITEBACK
		int way;
		int nr_ways = current_cpu_data.dcache.ways;
		for (way = 0; way < nr_ways; way++)
			sh2a_flush_oc_line(v, way);
#endif
		sh2a_invalidate_line(CACHE_OC_ADDRESS_ARRAY, v);
	}

	back_to_cached();
	local_irq_restore(flags);
}

/*
 * Invalidate the D-caches, but no write back please
 */
static void sh2a__flush_invalidate_region(void *start, int size)
{
	unsigned long v;
	unsigned long begin, end;
	unsigned long flags;

	begin = (unsigned long)start & ~(L1_CACHE_BYTES-1);
	end = ((unsigned long)start + size + L1_CACHE_BYTES-1)
		& ~(L1_CACHE_BYTES-1);

	local_irq_save(flags);
	jump_to_uncached();

	/* If there are too many pages then just blow the cache */
	if (((end - begin) >> PAGE_SHIFT) >= MAX_OCACHE_PAGES) {
		__raw_writel(__raw_readl(CCR) | CCR_OCACHE_INVALIDATE, CCR);
	} else {
		for (v = begin; v < end; v += L1_CACHE_BYTES)
			sh2a_invalidate_line(CACHE_OC_ADDRESS_ARRAY, v);
	}

	back_to_cached();
	local_irq_restore(flags);
}

/*
 * Write back the range of D-cache, and purge the I-cache.
 */
static void sh2a_flush_icache_range(void *args)
{
	struct flusher_data *data = args;
	unsigned long start, end;
	unsigned long v;
	unsigned long flags;

	start = data->addr1 & ~(L1_CACHE_BYTES-1);
	end = (data->addr2 + L1_CACHE_BYTES-1) & ~(L1_CACHE_BYTES-1);

#ifdef CONFIG_CACHE_WRITEBACK
	sh2a__flush_wback_region((void *)start, end-start);
#endif

	local_irq_save(flags);
	jump_to_uncached();

	/* I-Cache invalidate */
	/* If there are too many pages then just blow the cache */
	if (((end - start) >> PAGE_SHIFT) >= MAX_ICACHE_PAGES) {
		__raw_writel(__raw_readl(CCR) | CCR_ICACHE_INVALIDATE, CCR);
	} else {
		for (v = start; v < end; v += L1_CACHE_BYTES)
			sh2a_invalidate_line(CACHE_IC_ADDRESS_ARRAY, v);
	}

	back_to_cached();
	local_irq_restore(flags);
}

void __init sh2a_cache_init(void)
{
	local_flush_icache_range	= sh2a_flush_icache_range;

	__flush_wback_region		= sh2a__flush_wback_region;
	__flush_purge_region		= sh2a__flush_purge_region;
	__flush_invalidate_region	= sh2a__flush_invalidate_region;
}