From 1a8e41cd672f894bbd74874eac601e6cedf838fb Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Thu, 16 Sep 2010 17:57:17 +0100 Subject: ARM: 6395/1: VExpress: Set bit 22 in the PL310 (cache controller) AuxCtlr register Clearing bit 22 in the PL310 Auxiliary Control register (shared attribute override enable) has the side effect of transforming Normal Shared Non-cacheable reads into Cacheable no-allocate reads. Coherent DMA buffers in Linux always have a Cacheable alias via the kernel linear mapping and the processor can speculatively load cache lines into the PL310 controller. With bit 22 cleared, Non-cacheable reads would unexpectedly hit such cache lines leading to buffer corruption. Cc: Nicolas Pitre Cc: Signed-off-by: Catalin Marinas Signed-off-by: Russell King --- arch/arm/mach-vexpress/ct-ca9x4.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm/mach-vexpress/ct-ca9x4.c') diff --git a/arch/arm/mach-vexpress/ct-ca9x4.c b/arch/arm/mach-vexpress/ct-ca9x4.c index 577df6cccb08..1c9c13e9d074 100644 --- a/arch/arm/mach-vexpress/ct-ca9x4.c +++ b/arch/arm/mach-vexpress/ct-ca9x4.c @@ -227,7 +227,7 @@ static void ct_ca9x4_init(void) int i; #ifdef CONFIG_CACHE_L2X0 - l2x0_init(MMIO_P2V(CT_CA9X4_L2CC), 0x00000000, 0xfe0fffff); + l2x0_init(MMIO_P2V(CT_CA9X4_L2CC), 0x00400000, 0xfe0fffff); #endif clkdev_add_table(lookups, ARRAY_SIZE(lookups)); -- cgit v1.2.3 From 2de59fea8b3095d1df4c729fda041625930aab4f Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 27 Sep 2010 14:55:15 +0100 Subject: 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 Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/mach-vexpress/ct-ca9x4.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'arch/arm/mach-vexpress/ct-ca9x4.c') 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)); -- cgit v1.2.3