ARM: 6411/1: vexpress: set RAM latencies to 1 cycle for PL310 on ct-ca9x4 tile

The PL310 on the ct-ca9x4 tile for the Versatile Express does not need
to add additional latency when accessing its cache RAMs. Unfortunately,
the boot monitor sets this up for an 8-cycle delay on reads and writes,
resulting in greatly reduced memory performance when the L2 cache is
enabled.

This patch sets the L2 RAM latencies to the correct value of 1 cycle
on the ct-ca9x4 tile before enabling the L2 cache.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Will Deacon 2010-09-27 14:55:15 +01:00 committed by Russell King
parent 2de5c00ac0
commit 2de59fea8b

View file

@ -227,7 +227,13 @@ static void ct_ca9x4_init(void)
int i;
#ifdef CONFIG_CACHE_L2X0
l2x0_init(MMIO_P2V(CT_CA9X4_L2CC), 0x00400000, 0xfe0fffff);
void __iomem *l2x0_base = MMIO_P2V(CT_CA9X4_L2CC);
/* set RAM latencies to 1 cycle for this core tile. */
writel(0, l2x0_base + L2X0_TAG_LATENCY_CTRL);
writel(0, l2x0_base + L2X0_DATA_LATENCY_CTRL);
l2x0_init(l2x0_base, 0x00400000, 0xfe0fffff);
#endif
clkdev_add_table(lookups, ARRAY_SIZE(lookups));