From 0eb948dd7f7c3cec37440c16a6c738c8e75efcda Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 19 Nov 2009 11:12:15 +0000 Subject: [PATCH] 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: Russell King Acked-by: Catalin Marinas --- arch/arm/mm/cache-l2x0.c | 65 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 52 insertions(+), 13 deletions(-) diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index b480f1d..c1b7bff 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -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) -- 2.7.4