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arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

RFC PATCH New Daniel Walker 5 participants 8 messages Jan 28, 2010 – Jan 29, 2010 Arm (32-bit)

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#0 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

From: Larry Bassel <[email protected]>

This change improves the following LMBench benchmarks by over 15%:

System Call Latency
Signal Handling Latency
Fault Latency
Inter-process Communication Latency Inter-process Communication Bandwidth Random Number Generation Latency

Cc Catalin Marinas <[email protected]>
Cc Shilimkar, Santosh <[email protected]>
Cc Nicolas Pitre <[email protected]>
Cc Bohan, Michael <[email protected]>
---
 arch/arm/mm/proc-v7.S |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
arch/arm/mm/proc-v7.S +5 -0
index 7aaf88a..3ca5d29 100644
@@ -2,6 +2,7 @@
  *  linux/arch/arm/mm/proc-v7.S
  *
  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
+ *  Copyright (c) 2009, Code Aurora Forum. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -242,6 +243,10 @@ __v7_setup:
 	mcr	p15, 0, r4, c2, c0, 1		@ load TTB1
 	mov	r10, #0x1f			@ domains 0, 1 = manager
 	mcr	p15, 0, r10, c3, c0, 0		@ load domain access register
+#ifdef CONFIG_ARCH_MSM_SCORPION
+	mov     r0, #0x77
+	mcr     p15, 3, r0, c15, c0, 3          @ set L2CR1
+#endif
 	/*
 	 * Memory region attributes with SCTLR.TRE=1
 	 *
Signature · 1 line
1.6.3.3
#1 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

Quoted 28 lines · Daniel Walker

From: Larry Bassel <[email protected]>

This change improves the following LMBench benchmarks by over 15%:

System Call Latency
Signal Handling Latency
Fault Latency
Inter-process Communication Latency Inter-process Communication Bandwidth Random Number Generation Latency

Cc Catalin Marinas <[email protected]>
Cc Shilimkar, Santosh <[email protected]>
Cc Nicolas Pitre <[email protected]>
Cc Bohan, Michael <[email protected]>
---
 arch/arm/mm/proc-v7.S |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
arch/arm/mm/proc-v7.S +0 -0
index 7aaf88a..3ca5d29 100644

arch/arm/mm/proc-v7.S line 5

Quoted 4 lines
arch/arm/mm/proc-v7.S +1 -0
@@ -2,6 +2,7 @@
  *  linux/arch/arm/mm/proc-v7.S
  *
  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
+ *  Copyright (c) 2009, Code Aurora Forum. All rights reserved.

Do you really think the addition of only 4 lines in a file that contains 348 lines justifies the addition of such copyright notice? What would the kernel source looks like if everyone adding/modifying 4 lines in every random files did the same?

Just a thought.

Quoted 16 lines
arch/arm/mm/proc-v7.S +4 -0
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -242,6 +243,10 @@ __v7_setup:
 	mcr	p15, 0, r4, c2, c0, 1		@ load TTB1
 	mov	r10, #0x1f			@ domains 0, 1 = manager
 	mcr	p15, 0, r10, c3, c0, 0		@ load domain access register
+#ifdef CONFIG_ARCH_MSM_SCORPION
+	mov     r0, #0x77
+	mcr     p15, 3, r0, c15, c0, 3          @ set L2CR1
+#endif
 	/*
 	 * Memory region attributes with SCTLR.TRE=1
 	 *
Signature · 1 line
1.6.3.3
#2 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

Quoted 7 lines · Nicolas Pitre

Do you really think the addition of only 4 lines in a file that contains 348 lines justifies the addition of such copyright notice? What would the kernel source looks like if everyone adding/modifying 4 lines in every random files did the same?

Just a thought.

I don't disagree with you. It's actually a legal policy .. I can ask some questions regard it tho ..

Daniel

#3 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

Quoted 7 lines · Daniel Walker
Quoted 5 lines · Nicolas Pitre

Do you really think the addition of only 4 lines in a file that contains 348 lines justifies the addition of such copyright notice? What would the kernel source looks like if everyone adding/modifying 4 lines in every random files did the same?

Quoted 5 lines
Quoted 2 lines

Just a thought.

I don't disagree with you. It's actually a legal policy .. I can ask some questions regard it tho ..

The legalese is usually satisfied by the attribution and the meaning attached to the SOB carried in the commit message.

Nicolas

#4 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

In reply to Daniel Walker
Quoted 5 lines

I don't disagree with you. It's actually a legal policy .. I can ask some questions regard it tho ..

Daniel

It's fine to remove the Code Aurora copyright from this patch. As Nicolas noted, it shouldn't have been in there in the first place.

- Bryan

#5 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

In reply to Daniel Walker

Hi!

Quoted 4 lines

From: Larry Bassel <[email protected]>

This change improves the following LMBench benchmarks by over 15%:

But what does this change do?

arch/arm/mm/proc-v7.S __v7_setup: · line 249

Quoted 8 lines
arch/arm/mm/proc-v7.S +4 -0
@@ -242,6 +243,10 @@ __v7_setup:
 	mcr	p15, 0, r4, c2, c0, 1		@ load TTB1
 	mov	r10, #0x1f			@ domains 0, 1 = manager
 	mcr	p15, 0, r10, c3, c0, 0		@ load domain access register
+#ifdef CONFIG_ARCH_MSM_SCORPION
+	mov     r0, #0x77
+	mcr     p15, 3, r0, c15, c0, 3          @ set L2CR1
+#endif

...probably should be explained here...

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#6 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

In reply to Daniel Walker

arch/arm/mm/proc-v7.S __v7_setup: · line 249

Quoted 8 lines · Daniel Walker
arch/arm/mm/proc-v7.S +4 -0
@@ -242,6 +243,10 @@ __v7_setup:
        mcr     p15, 0, r4, c2, c0, 1           @ load TTB1
        mov     r10, #0x1f                      @ domains 0, 1 = manager
        mcr     p15, 0, r10, c3, c0, 0          @ load domain access register
+#ifdef CONFIG_ARCH_MSM_SCORPION
+       mov     r0, #0x77
+       mcr     p15, 3, r0, c15, c0, 3          @ set L2CR1
+#endif

I thought we want to move these out of the kernel into the boot loader (or boot monitor or bios or whatever it's called).

Signature · 1 line
Catalin
#7 lore raw

RFC PATCH 6/12 arm: msm: set L2CR1 to enable prefetch and burst on Scorpion.

Quoted 12 lines · Catalin Marinas

arch/arm/mm/proc-v7.S __v7_setup: · line 249

Quoted 8 lines · Daniel Walker
arch/arm/mm/proc-v7.S +4 -0
@@ -242,6 +243,10 @@ __v7_setup:
        mcr     p15, 0, r4, c2, c0, 1           @ load TTB1
        mov     r10, #0x1f                      @ domains 0, 1 = manager
        mcr     p15, 0, r10, c3, c0, 0          @ load domain access register
+#ifdef CONFIG_ARCH_MSM_SCORPION
+       mov     r0, #0x77
+       mcr     p15, 3, r0, c15, c0, 3          @ set L2CR1
+#endif

I thought we want to move these out of the kernel into the boot loader (or boot monitor or bios or whatever it's called).

I left it in cause it still felt like an open question the last time I submitted it ..

Honestly, I feel like we should keep as much control in Linux as possible.. Having it in Linux is just one place for it to get screwed up, vs. having it in many different boot loaders.

Daniel