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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>
hifive-unleashed-5.1
Arnd Bergmann 2015-01-28 17:55:31 +01:00 committed by Russell King
parent 20e783e39e
commit 1d88967900
1 changed files with 22 additions and 46 deletions
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68
arch/arm/mm/cache-l2x0.c
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@ -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)