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Commit c1537b48 authored by Phil Edworthy's avatar Phil Edworthy Committed by Paul Mundt
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sh: sh2a: Improve cache flush/invalidate functions 



The cache functions lock out interrupts for long periods; this patch
reduces the impact when operating on large address ranges. In such
cases it will:
- Invalidate the entire cache rather than individual addresses.
- Do nothing when flushing the operand cache in write-through mode.
- When flushing the operand cache in write-back mdoe, index the
  search for matching addresses on the cache entires instead of the
  addresses to flush

Note: sh2a__flush_purge_region was only invalidating the operand
cache, this adds flush.

Signed-off-by: default avatarPhil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent e343a895

arch/sh/mm/cache-sh2a.c

+84 −39
Original line number Diff line number Diff line
@@ -15,35 +15,78 @@ 
#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



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);

	}

}



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 addr = CACHE_OC_ADDRESS_ARRAY | (v & 0x000007f0);

		int way;

		for (way = 0; way < 4; way++) {

			unsigned long data =  __raw_readl(addr | (way << 11));

			if ((data & CACHE_PHYSADDR_MASK) == (v & CACHE_PHYSADDR_MASK)) {

				data &= ~SH_CACHE_UPDATED;

				__raw_writel(data, addr | (way << 11));

			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;
@@ -58,13 +101,22 @@ static void sh2a__flush_purge_region(void *start, int size) 
	jump_to_uncached();



	for (v = begin; v < end; v+=L1_CACHE_BYTES) {

		__raw_writel((v & CACHE_PHYSADDR_MASK),

			  CACHE_OC_ADDRESS_ARRAY | (v & 0x000007f0) | 0x00000008);

#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;
@@ -74,29 +126,25 @@ static void sh2a__flush_invalidate_region(void *start, int size) 
	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();



#ifdef CONFIG_CACHE_WRITEBACK

	/* 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);

	/* I-cache invalidate */

	for (v = begin; v < end; v+=L1_CACHE_BYTES) {

		__raw_writel((v & CACHE_PHYSADDR_MASK),

			  CACHE_IC_ADDRESS_ARRAY | (v & 0x000007f0) | 0x00000008);

	} else {

		for (v = begin; v < end; v += L1_CACHE_BYTES)

			sh2a_invalidate_line(CACHE_OC_ADDRESS_ARRAY, v);

	}

#else

	for (v = begin; v < end; v+=L1_CACHE_BYTES) {

		__raw_writel((v & CACHE_PHYSADDR_MASK),

			  CACHE_IC_ADDRESS_ARRAY | (v & 0x000007f0) | 0x00000008);

		__raw_writel((v & CACHE_PHYSADDR_MASK),

			  CACHE_OC_ADDRESS_ARRAY | (v & 0x000007f0) | 0x00000008);

	}

#endif



	back_to_cached();

	local_irq_restore(flags);

}



/* WBack O-Cache and flush I-Cache */

/*

 * 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;
@@ -107,23 +155,20 @@ static void sh2a_flush_icache_range(void *args) 
	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();



	for (v = start; v < end; v+=L1_CACHE_BYTES) {

		unsigned long addr = (v & 0x000007f0);

		int way;

		/* O-Cache writeback */

		for (way = 0; way < 4; way++) {

			unsigned long data =  __raw_readl(CACHE_OC_ADDRESS_ARRAY | addr | (way << 11));

			if ((data & CACHE_PHYSADDR_MASK) == (v & CACHE_PHYSADDR_MASK)) {

				data &= ~SH_CACHE_UPDATED;

				__raw_writel(data, CACHE_OC_ADDRESS_ARRAY | addr | (way << 11));

			}

		}

	/* I-Cache invalidate */

		__raw_writel(addr,

			  CACHE_IC_ADDRESS_ARRAY | addr | 0x00000008);

	/* 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();