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| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2014-11-25 18:43:15 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-12-06 15:55:37 -0800 |
| commit | c84eb54a06e525d9b290a2c80fdd42f06d2c0380 (patch) | |
| tree | 9bd021534f48b674454e52ec7f98b5fb418530ad /arch | |
| parent | 80eb5395671d378f308aa68599f96089c1427b1f (diff) | |
| download | lwn-c84eb54a06e525d9b290a2c80fdd42f06d2c0380.tar.gz lwn-c84eb54a06e525d9b290a2c80fdd42f06d2c0380.zip | |
ARM: 8222/1: mvebu: enable strex backoff delay
commit 995ab5189d1d7264e79e665dfa032a19b3ac646e upstream.
Under extremely rare conditions, in an MPCore node consisting of at
least 3 CPUs, two CPUs trying to perform a STREX to data on the same
shared cache line can enter a livelock situation.
This patch enables the HW mechanism that overcomes the bug. This fixes
the incorrect setup of the STREX backoff delay bit due to a wrong
description in the specification.
Note that enabling the STREX backoff delay mechanism is done by
leaving the bit *cleared*, while the bit was currently being set by
the proc-v7.S code.
[Thomas: adapt to latest mainline, slightly reword the commit log, add
stable markers.]
Fixes: de4901933f6d ("arm: mm: Add support for PJ4B cpu and init routines")
Signed-off-by: Nadav Haklai <nadavh@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/mm/proc-v7.S | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 74f6033e76dd..fdedc31e0f40 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -211,7 +211,6 @@ __v7_pj4b_setup: /* Auxiliary Debug Modes Control 1 Register */ #define PJ4B_STATIC_BP (1 << 2) /* Enable Static BP */ #define PJ4B_INTER_PARITY (1 << 8) /* Disable Internal Parity Handling */ -#define PJ4B_BCK_OFF_STREX (1 << 5) /* Enable the back off of STREX instr */ #define PJ4B_CLEAN_LINE (1 << 16) /* Disable data transfer for clean line */ /* Auxiliary Debug Modes Control 2 Register */ @@ -234,7 +233,6 @@ __v7_pj4b_setup: /* Auxiliary Debug Modes Control 1 Register */ mrc p15, 1, r0, c15, c1, 1 orr r0, r0, #PJ4B_CLEAN_LINE - orr r0, r0, #PJ4B_BCK_OFF_STREX orr r0, r0, #PJ4B_INTER_PARITY bic r0, r0, #PJ4B_STATIC_BP mcr p15, 1, r0, c15, c1, 1 |