From cf0681ca4cc5c9faa85a2df4c063b926fc09c977 Mon Sep 17 00:00:00 2001 From: Tomasz Figa Date: Thu, 8 Jan 2015 07:52:38 +0100 Subject: [PATCH] ARM: 8262/1: l2c: Add support for overriding prefetch settings Firmware on certain boards (e.g. ODROID-U3) can leave incorrect L2C prefetch settings configured in registers leading to crashes if L2C is enabled without overriding them. This patch introduces bindings to enable prefetch settings to be specified from DT and necessary support in the driver. [mszyprow: rebased onto v3.18-rc1, added error message when prefetch related dt property has been provided without any value] Signed-off-by: Tomasz Figa Signed-off-by: Marek Szyprowski Tested-by: Nishanth Menon Acked-by: Nishanth Menon Acked-by: Tony Lindgren Signed-off-by: Russell King --- Documentation/devicetree/bindings/arm/l2cc.txt | 10 +++++ arch/arm/mm/cache-l2x0.c | 54 ++++++++++++++++++++++++++ 2 files changed, 64 insertions(+) diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt index 292ef7c..0dbabe9 100644 --- a/Documentation/devicetree/bindings/arm/l2cc.txt +++ b/Documentation/devicetree/bindings/arm/l2cc.txt @@ -57,6 +57,16 @@ Optional properties: - cache-id-part: cache id part number to be used if it is not present on hardware - wt-override: If present then L2 is forced to Write through mode +- arm,double-linefill : Override double linefill enable setting. Enable if + non-zero, disable if zero. +- arm,double-linefill-incr : Override double linefill on INCR read. Enable + if non-zero, disable if zero. +- arm,double-linefill-wrap : Override double linefill on WRAP read. Enable + if non-zero, disable if zero. +- arm,prefetch-drop : Override prefetch drop enable setting. Enable if non-zero, + disable if zero. +- arm,prefetch-offset : Override prefetch offset value. Valid values are + 0-7, 15, 23, and 31. Example: diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index 5288153..01de138 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c @@ -1169,6 +1169,8 @@ static void __init l2c310_of_parse(const struct device_node *np, u32 tag[3] = { 0, 0, 0 }; u32 filter[2] = { 0, 0 }; u32 assoc; + u32 prefetch; + u32 val; int ret; of_property_read_u32_array(np, "arm,tag-latency", tag, ARRAY_SIZE(tag)); @@ -1214,6 +1216,58 @@ static void __init l2c310_of_parse(const struct device_node *np, assoc); break; } + + prefetch = l2x0_saved_regs.prefetch_ctrl; + + ret = of_property_read_u32(np, "arm,double-linefill", &val); + if (ret == 0) { + if (val) + prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL; + else + prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF arm,double-linefill property value is missing\n"); + } + + ret = of_property_read_u32(np, "arm,double-linefill-incr", &val); + if (ret == 0) { + if (val) + prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL_INCR; + else + prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL_INCR; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF arm,double-linefill-incr property value is missing\n"); + } + + ret = of_property_read_u32(np, "arm,double-linefill-wrap", &val); + if (ret == 0) { + if (!val) + prefetch |= L310_PREFETCH_CTRL_DBL_LINEFILL_WRAP; + else + prefetch &= ~L310_PREFETCH_CTRL_DBL_LINEFILL_WRAP; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF arm,double-linefill-wrap property value is missing\n"); + } + + ret = of_property_read_u32(np, "arm,prefetch-drop", &val); + if (ret == 0) { + if (val) + prefetch |= L310_PREFETCH_CTRL_PREFETCH_DROP; + else + prefetch &= ~L310_PREFETCH_CTRL_PREFETCH_DROP; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF arm,prefetch-drop property value is missing\n"); + } + + ret = of_property_read_u32(np, "arm,prefetch-offset", &val); + if (ret == 0) { + prefetch &= ~L310_PREFETCH_CTRL_OFFSET_MASK; + prefetch |= val & L310_PREFETCH_CTRL_OFFSET_MASK; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF arm,prefetch-offset property value is missing\n"); + } + + l2x0_saved_regs.prefetch_ctrl = prefetch; } static const struct l2c_init_data of_l2c310_data __initconst = { -- 2.7.4