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authorWill Deacon <will.deacon@arm.com>2010-09-27 14:55:15 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-09-27 14:57:36 +0100
commit2de59fea8b3095d1df4c729fda041625930aab4f (patch)
treeb7d5e28e4da11607c74a7ed99c3bd2f93473a8fd /arch
parent2de5c00ac06c8983ab33ad51a8341584f1cf42c3 (diff)
downloadblackbird-op-linux-2de59fea8b3095d1df4c729fda041625930aab4f.tar.gz
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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>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-vexpress/ct-ca9x4.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/arm/mach-vexpress/ct-ca9x4.c b/arch/arm/mach-vexpress/ct-ca9x4.c
index 1c9c13e9d074..efb127022d42 100644
--- a/arch/arm/mach-vexpress/ct-ca9x4.c
+++ b/arch/arm/mach-vexpress/ct-ca9x4.c
@@ -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));
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