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Commit 0eb948dd authored by Russell King's avatar Russell King
Browse files

ARM: cache-l2x0: avoid taking spinlock for every iteration 



Taking the spinlock for every iteration is very expensive; instead,
batch iterations up into 4K blocks, releasing and reacquiring the
spinlock between each block.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 22763c5c

arch/arm/mm/cache-l2x0.c

+52 −13
Original line number Diff line number Diff line
@@ -31,14 +31,10 @@ static DEFINE_SPINLOCK(l2x0_lock); 
static inline void sync_writel(unsigned long val, unsigned long reg,

			       unsigned long complete_mask)

{

	unsigned long flags;



	spin_lock_irqsave(&l2x0_lock, flags);

	writel(val, l2x0_base + reg);

	/* wait for the operation to complete */

	while (readl(l2x0_base + reg) & complete_mask)

		;

	spin_unlock_irqrestore(&l2x0_lock, flags);

}



static inline void cache_sync(void)
@@ -48,15 +44,20 @@ static inline void cache_sync(void) 


static inline void l2x0_inv_all(void)

{

	unsigned long flags;



	/* invalidate all ways */

	spin_lock_irqsave(&l2x0_lock, flags);

	sync_writel(0xff, L2X0_INV_WAY, 0xff);

	cache_sync();

	spin_unlock_irqrestore(&l2x0_lock, flags);

}



static void l2x0_inv_range(unsigned long start, unsigned long end)

{

	unsigned long addr;

	unsigned long flags;



	spin_lock_irqsave(&l2x0_lock, flags);

	if (start & (CACHE_LINE_SIZE - 1)) {

		start &= ~(CACHE_LINE_SIZE - 1);

		sync_writel(start, L2X0_CLEAN_INV_LINE_PA, 1);
@@ -68,29 +69,67 @@ static void l2x0_inv_range(unsigned long start, unsigned long end) 
		sync_writel(end, L2X0_CLEAN_INV_LINE_PA, 1);

	}



	for (addr = start; addr < end; addr += CACHE_LINE_SIZE)

		sync_writel(addr, L2X0_INV_LINE_PA, 1);

	while (start < end) {

		unsigned long blk_end = start + min(end - start, 4096UL);



		while (start < blk_end) {

			sync_writel(start, L2X0_INV_LINE_PA, 1);

			start += CACHE_LINE_SIZE;

		}



		if (blk_end < end) {

			spin_unlock_irqrestore(&l2x0_lock, flags);

			spin_lock_irqsave(&l2x0_lock, flags);

		}

	}

	cache_sync();

	spin_unlock_irqrestore(&l2x0_lock, flags);

}



static void l2x0_clean_range(unsigned long start, unsigned long end)

{

	unsigned long addr;

	unsigned long flags;



	spin_lock_irqsave(&l2x0_lock, flags);

	start &= ~(CACHE_LINE_SIZE - 1);

	for (addr = start; addr < end; addr += CACHE_LINE_SIZE)

		sync_writel(addr, L2X0_CLEAN_LINE_PA, 1);

	while (start < end) {

		unsigned long blk_end = start + min(end - start, 4096UL);



		while (start < blk_end) {

			sync_writel(start, L2X0_CLEAN_LINE_PA, 1);

			start += CACHE_LINE_SIZE;

		}



		if (blk_end < end) {

			spin_unlock_irqrestore(&l2x0_lock, flags);

			spin_lock_irqsave(&l2x0_lock, flags);

		}

	}

	cache_sync();

	spin_unlock_irqrestore(&l2x0_lock, flags);

}



static void l2x0_flush_range(unsigned long start, unsigned long end)

{

	unsigned long addr;

	unsigned long flags;



	spin_lock_irqsave(&l2x0_lock, flags);

	start &= ~(CACHE_LINE_SIZE - 1);

	for (addr = start; addr < end; addr += CACHE_LINE_SIZE)

		sync_writel(addr, L2X0_CLEAN_INV_LINE_PA, 1);

	while (start < end) {

		unsigned long blk_end = start + min(end - start, 4096UL);



		while (start < blk_end) {

			sync_writel(start, L2X0_CLEAN_INV_LINE_PA, 1);

			start += CACHE_LINE_SIZE;

		}



		if (blk_end < end) {

			spin_unlock_irqrestore(&l2x0_lock, flags);

			spin_lock_irqsave(&l2x0_lock, flags);

		}

	}

	cache_sync();

	spin_unlock_irqrestore(&l2x0_lock, flags);

}



void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)