[PATCH v4] ARM: l2c: add options to overwrite prefetching behavior
From: f.fainelli@gmail.com (Florian Fainelli)
Date: 2015-06-10 16:57:18
Also in:
linux-devicetree
On 29/05/15 16:19, Hauke Mehrtens wrote:
These options make it possible to overwrites the data and instruction prefetching behavior of the arm pl310 cache controller. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
quoted hunk
--- changes since v3: * remove arm prefix * improve documentation v2: only set prefetch v1: set prefetch and aux Documentation/devicetree/bindings/arm/l2cc.txt | 5 +++++ arch/arm/mm/cache-l2x0.c | 20 ++++++++++++++++++++ 2 files changed, 25 insertions(+)diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt index 0dbabe9..2251dcc 100644 --- a/Documentation/devicetree/bindings/arm/l2cc.txt +++ b/Documentation/devicetree/bindings/arm/l2cc.txt@@ -67,6 +67,11 @@ Optional properties: disable if zero. - arm,prefetch-offset : Override prefetch offset value. Valid values are 0-7, 15, 23, and 31. +- prefetch-data : Data prefetch. Value: <0> (forcibly disable), <1> + (forcibly enable), property absent (retain settings set by firmware) +- prefetch-instr : Instruction prefetch. Value: <0> (forcibly disable), + <1> (forcibly enable), property absent (retain settings set by + firmware) Example:diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c index e309c8f..2570f83 100644 --- a/arch/arm/mm/cache-l2x0.c +++ b/arch/arm/mm/cache-l2x0.c@@ -1199,6 +1199,26 @@ static void __init l2c310_of_parse(const struct device_node *np, pr_err("L2C-310 OF arm,prefetch-offset property value is missing\n"); } + ret = of_property_read_u32(np, "prefetch-data", &val); + if (ret == 0) { + if (val) + prefetch |= L310_PREFETCH_CTRL_DATA_PREFETCH; + else + prefetch &= ~L310_PREFETCH_CTRL_DATA_PREFETCH; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF prefetch-data property value is missing\n"); + } + + ret = of_property_read_u32(np, "prefetch-instr", &val); + if (ret == 0) { + if (val) + prefetch |= L310_PREFETCH_CTRL_INSTR_PREFETCH; + else + prefetch &= ~L310_PREFETCH_CTRL_INSTR_PREFETCH; + } else if (ret != -EINVAL) { + pr_err("L2C-310 OF prefetch-instr property value is missing\n"); + } + l2x0_saved_regs.prefetch_ctrl = prefetch; }
-- Florian