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authorArnd Bergmann <arnd@arndb.de>2015-01-28 17:55:31 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-02-06 21:16:40 +0100
commit1d88967900b87f94435581dad4ae319686c6ce10 (patch)
tree7fc8d85ca097dfdb6a49276061ffb1466723ef0c
parentARM: 8296/1: cache-l2x0: clean up aurora cache handling (diff)
downloadlinux-1d88967900b87f94435581dad4ae319686c6ce10.tar.xz
linux-1d88967900b87f94435581dad4ae319686c6ce10.zip
ARM: 8297/1: cache-l2x0: optimize aurora range operations
The aurora_inv_range(), aurora_clean_range() and aurora_flush_range() functions are highly redundant, both in source and in object code, and they are harder to understand than necessary. By moving the range loop into the aurora_pa_range() function, they become trivial wrappers, and the object code start looking like what one would expect for an optimal implementation. Further optimization may be possible by using the per-CPU "virtual" registers to avoid the spinlocks in most cases. (on Armada 370 RD and Armada XP GP, boot tested, plus a little bit of DMA traffic by reading data from a SD card) Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/mm/cache-l2x0.c68
1 files changed, 22 insertions, 46 deletions
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 404c598da27d..5ea2d6d417f7 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1256,7 +1256,7 @@ static const struct l2c_init_data of_l2c310_coherent_data __initconst = {
* noninclusive, while the hardware cache range operations use
* inclusive start and end addresses.
*/
-static unsigned long calc_range_end(unsigned long start, unsigned long end)
+static unsigned long aurora_range_end(unsigned long start, unsigned long end)
{
/*
* Limit the number of cache lines processed at once,
@@ -1275,26 +1275,13 @@ static unsigned long calc_range_end(unsigned long start, unsigned long end)
return end;
}
-/*
- * Make sure 'start' and 'end' reference the same page, as L2 is PIPT
- * and range operations only do a TLB lookup on the start address.
- */
static void aurora_pa_range(unsigned long start, unsigned long end,
- unsigned long offset)
+ unsigned long offset)
{
void __iomem *base = l2x0_base;
+ unsigned long range_end;
unsigned long flags;
- raw_spin_lock_irqsave(&l2x0_lock, flags);
- writel_relaxed(start, base + AURORA_RANGE_BASE_ADDR_REG);
- writel_relaxed(end, base + offset);
- raw_spin_unlock_irqrestore(&l2x0_lock, flags);
-
- writel_relaxed(0, base + AURORA_SYNC_REG);
-}
-
-static void aurora_inv_range(unsigned long start, unsigned long end)
-{
/*
* round start and end adresses up to cache line size
*/
@@ -1302,15 +1289,24 @@ static void aurora_inv_range(unsigned long start, unsigned long end)
end = ALIGN(end, CACHE_LINE_SIZE);
/*
- * Invalidate all full cache lines between 'start' and 'end'.
+ * perform operation on all full cache lines between 'start' and 'end'
*/
while (start < end) {
- unsigned long range_end = calc_range_end(start, end);
- aurora_pa_range(start, range_end - CACHE_LINE_SIZE,
- AURORA_INVAL_RANGE_REG);
+ range_end = aurora_range_end(start, end);
+
+ raw_spin_lock_irqsave(&l2x0_lock, flags);
+ writel_relaxed(start, base + AURORA_RANGE_BASE_ADDR_REG);
+ writel_relaxed(range_end - CACHE_LINE_SIZE, base + offset);
+ raw_spin_unlock_irqrestore(&l2x0_lock, flags);
+
+ writel_relaxed(0, base + AURORA_SYNC_REG);
start = range_end;
}
}
+static void aurora_inv_range(unsigned long start, unsigned long end)
+{
+ aurora_pa_range(start, end, AURORA_INVAL_RANGE_REG);
+}
static void aurora_clean_range(unsigned long start, unsigned long end)
{
@@ -1318,36 +1314,16 @@ static void aurora_clean_range(unsigned long start, unsigned long end)
* If L2 is forced to WT, the L2 will always be clean and we
* don't need to do anything here.
*/
- if (!l2_wt_override) {
- start &= ~(CACHE_LINE_SIZE - 1);
- end = ALIGN(end, CACHE_LINE_SIZE);
- while (start != end) {
- unsigned long range_end = calc_range_end(start, end);
- aurora_pa_range(start, range_end - CACHE_LINE_SIZE,
- AURORA_CLEAN_RANGE_REG);
- start = range_end;
- }
- }
+ if (!l2_wt_override)
+ aurora_pa_range(start, end, AURORA_CLEAN_RANGE_REG);
}
static void aurora_flush_range(unsigned long start, unsigned long end)
{
- start &= ~(CACHE_LINE_SIZE - 1);
- end = ALIGN(end, CACHE_LINE_SIZE);
- while (start != end) {
- unsigned long range_end = calc_range_end(start, end);
- /*
- * If L2 is forced to WT, the L2 will always be clean and we
- * just need to invalidate.
- */
- if (l2_wt_override)
- aurora_pa_range(start, range_end - CACHE_LINE_SIZE,
- AURORA_INVAL_RANGE_REG);
- else
- aurora_pa_range(start, range_end - CACHE_LINE_SIZE,
- AURORA_FLUSH_RANGE_REG);
- start = range_end;
- }
+ if (l2_wt_override)
+ aurora_pa_range(start, end, AURORA_INVAL_RANGE_REG);
+ else
+ aurora_pa_range(start, end, AURORA_FLUSH_RANGE_REG);
}
static void aurora_flush_all(void)