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authorRussell King <rmk+kernel@arm.linux.org.uk>2009-11-19 11:12:15 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2009-12-14 13:34:58 +0000
commit0eb948dd7f7c3cec37440c16a6c738c8e75efcda (patch)
tree96ecc9b1a3b5326f7de82cd2055b448a7e43c9f8 /arch/arm
parent22763c5cf3690a681551162c15d34d935308c8d7 (diff)
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 <rmk+kernel@arm.linux.org.uk> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mm/cache-l2x0.c65
1 files changed, 52 insertions, 13 deletions
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index b480f1d3591..c1b7bfff47f 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)