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* [PATCH] ARM: l2c: add options to overwrite prefetching behavior
@ 2015-05-13 23:42 ` Hauke Mehrtens
  0 siblings, 0 replies; 4+ messages in thread
From: Hauke Mehrtens @ 2015-05-13 23:42 UTC (permalink / raw)
  To: linux, arnd
  Cc: devicetree, Hauke Mehrtens, linux-arm-kernel, geert+renesas,
	catalin.marinas

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>
---
 Documentation/devicetree/bindings/arm/l2cc.txt |  4 ++++
 arch/arm/mm/cache-l2x0.c                       | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt
index 0dbabe9..528821a 100644
--- a/Documentation/devicetree/bindings/arm/l2cc.txt
+++ b/Documentation/devicetree/bindings/arm/l2cc.txt
@@ -67,6 +67,10 @@ Optional properties:
   disable if zero.
 - arm,prefetch-offset : Override prefetch offset value. Valid values are
   0-7, 15, 23, and 31.
+- arm,prefetch-data : Enable data prefetch. Enabling prefetching
+  can improve performance.
+- arm,prefetch-instr : Enable instruction prefetch. Enabling prefetching
+  can improve performance.
 
 Example:
 
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index e309c8f..f919548 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1149,6 +1149,16 @@ static void __init l2c310_of_parse(const struct device_node *np,
 		}
 	}
 
+	if (of_property_read_bool(np, "arm,prefetch-data")) {
+		*aux_val |= L310_AUX_CTRL_DATA_PREFETCH;
+		*aux_mask &= ~L310_AUX_CTRL_DATA_PREFETCH;
+	}
+
+	if (of_property_read_bool(np, "arm,prefetch-instr")) {
+		*aux_val |= L310_AUX_CTRL_INSTR_PREFETCH;
+		*aux_mask &= ~L310_AUX_CTRL_INSTR_PREFETCH;
+	}
+
 	prefetch = l2x0_saved_regs.prefetch_ctrl;
 
 	ret = of_property_read_u32(np, "arm,double-linefill", &val);
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* [PATCH] ARM: l2c: add options to overwrite prefetching behavior
@ 2015-05-13 23:42 ` Hauke Mehrtens
  0 siblings, 0 replies; 4+ messages in thread
From: Hauke Mehrtens @ 2015-05-13 23:42 UTC (permalink / raw)
  To: linux-arm-kernel

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>
---
 Documentation/devicetree/bindings/arm/l2cc.txt |  4 ++++
 arch/arm/mm/cache-l2x0.c                       | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt
index 0dbabe9..528821a 100644
--- a/Documentation/devicetree/bindings/arm/l2cc.txt
+++ b/Documentation/devicetree/bindings/arm/l2cc.txt
@@ -67,6 +67,10 @@ Optional properties:
   disable if zero.
 - arm,prefetch-offset : Override prefetch offset value. Valid values are
   0-7, 15, 23, and 31.
+- arm,prefetch-data : Enable data prefetch. Enabling prefetching
+  can improve performance.
+- arm,prefetch-instr : Enable instruction prefetch. Enabling prefetching
+  can improve performance.
 
 Example:
 
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index e309c8f..f919548 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -1149,6 +1149,16 @@ static void __init l2c310_of_parse(const struct device_node *np,
 		}
 	}
 
+	if (of_property_read_bool(np, "arm,prefetch-data")) {
+		*aux_val |= L310_AUX_CTRL_DATA_PREFETCH;
+		*aux_mask &= ~L310_AUX_CTRL_DATA_PREFETCH;
+	}
+
+	if (of_property_read_bool(np, "arm,prefetch-instr")) {
+		*aux_val |= L310_AUX_CTRL_INSTR_PREFETCH;
+		*aux_mask &= ~L310_AUX_CTRL_INSTR_PREFETCH;
+	}
+
 	prefetch = l2x0_saved_regs.prefetch_ctrl;
 
 	ret = of_property_read_u32(np, "arm,double-linefill", &val);
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 4+ messages in thread
* Re: [PATCH] ARM: l2c: add options to overwrite prefetching behavior
  2015-05-13 23:42 ` Hauke Mehrtens
@ 2015-05-14  9:58     ` Russell King - ARM Linux
  -1 siblings, 0 replies; 4+ messages in thread
From: Russell King - ARM Linux @ 2015-05-14  9:58 UTC (permalink / raw)
  To: Hauke Mehrtens
  Cc: arnd-r2nGTMty4D4, geert+renesas-gXvu3+zWzMSzQB+pC5nmwQ,
	devicetree-u79uwXL29TY76Z2rM5mHXA,
	linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
	catalin.marinas-5wv7dgnIgG8

On Thu, May 14, 2015 at 01:42:00AM +0200, Hauke Mehrtens wrote:
> diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
> index e309c8f..f919548 100644
> --- a/arch/arm/mm/cache-l2x0.c
> +++ b/arch/arm/mm/cache-l2x0.c
> @@ -1149,6 +1149,16 @@ static void __init l2c310_of_parse(const struct device_node *np,
>  		}
>  	}
>  
> +	if (of_property_read_bool(np, "arm,prefetch-data")) {
> +		*aux_val |= L310_AUX_CTRL_DATA_PREFETCH;
> +		*aux_mask &= ~L310_AUX_CTRL_DATA_PREFETCH;
> +	}
> +
> +	if (of_property_read_bool(np, "arm,prefetch-instr")) {
> +		*aux_val |= L310_AUX_CTRL_INSTR_PREFETCH;
> +		*aux_mask &= ~L310_AUX_CTRL_INSTR_PREFETCH;
> +	}
> +
>  	prefetch = l2x0_saved_regs.prefetch_ctrl;
>  
>  	ret = of_property_read_u32(np, "arm,double-linefill", &val);

Please move these down along-side the "arm,prefetch-offset" property
parsing, and please update the prefetch value using
L310_PREFETCH_CTRL_DATA_PREFETCH and L310_PREFETCH_CTRL_INSTR_PREFETCH
instead.

These are in fact the same bit, but let's try to keep the prefetch
configuration all in one place and via the same method.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.
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^ permalink raw reply	[flat|nested] 4+ messages in thread
* [PATCH] ARM: l2c: add options to overwrite prefetching behavior
@ 2015-05-14  9:58     ` Russell King - ARM Linux
  0 siblings, 0 replies; 4+ messages in thread
From: Russell King - ARM Linux @ 2015-05-14  9:58 UTC (permalink / raw)
  To: linux-arm-kernel

On Thu, May 14, 2015 at 01:42:00AM +0200, Hauke Mehrtens wrote:
> diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
> index e309c8f..f919548 100644
> --- a/arch/arm/mm/cache-l2x0.c
> +++ b/arch/arm/mm/cache-l2x0.c
> @@ -1149,6 +1149,16 @@ static void __init l2c310_of_parse(const struct device_node *np,
>  		}
>  	}
>  
> +	if (of_property_read_bool(np, "arm,prefetch-data")) {
> +		*aux_val |= L310_AUX_CTRL_DATA_PREFETCH;
> +		*aux_mask &= ~L310_AUX_CTRL_DATA_PREFETCH;
> +	}
> +
> +	if (of_property_read_bool(np, "arm,prefetch-instr")) {
> +		*aux_val |= L310_AUX_CTRL_INSTR_PREFETCH;
> +		*aux_mask &= ~L310_AUX_CTRL_INSTR_PREFETCH;
> +	}
> +
>  	prefetch = l2x0_saved_regs.prefetch_ctrl;
>  
>  	ret = of_property_read_u32(np, "arm,double-linefill", &val);

Please move these down along-side the "arm,prefetch-offset" property
parsing, and please update the prefetch value using
L310_PREFETCH_CTRL_DATA_PREFETCH and L310_PREFETCH_CTRL_INSTR_PREFETCH
instead.

These are in fact the same bit, but let's try to keep the prefetch
configuration all in one place and via the same method.

-- 
FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up
according to speedtest.net.

^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-05-14  9:58 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2015-05-13 23:42 [PATCH] ARM: l2c: add options to overwrite prefetching behavior Hauke Mehrtens
2015-05-13 23:42 ` Hauke Mehrtens
     [not found] ` <1431560520-12544-1-git-send-email-hauke-5/S+JYg5SzeELgA04lAiVw@public.gmane.org>
2015-05-14  9:58   ` Russell King - ARM Linux
2015-05-14  9:58     ` Russell King - ARM Linux

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