From eabc12e1afe0bfc2f9e6f7bacae03985439df1a2 Mon Sep 17 00:00:00 2001 From: vdumpa Date: Wed, 27 Apr 2011 11:11:44 -0700 Subject: ARM: errata: 752520: Faulty arbitration between PLD and Cacheable TLB requests may create a system deadlock. Under rare circumstances, PLDs may interfere with a Cacheable page table walk, creating a processor deadlock. The erratum can only happen when the Data Cache and MMU are enabled, with the TLB descriptors marked as L1 cacheable, so that Page Table Walks are performed as cache linefills. This workaround sets a bit in the diagnostic register of the Cortex-A9, causing PLD operations treated as NOP. (cherry-picked from b501cafea7328bc578f67e3e846ab9d25b7ec1b0) Change-Id: Ic4039b83de43530bae7ce705162441bea74e1e98 Reviewed-on: http://git-master/r/54095 Reviewed-by: Krishna Reddy Tested-by: Krishna Reddy Reviewed-by: Yu-Huan Hsu Reviewed-by: Scott Williams Rebase-Id: Ra35e48e21c1d62b6480a9d67d1413dd5d0df3f53 --- arch/arm/mm/proc-v7.S | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/arm/mm') diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 8c165d905461..f85116d422d8 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -551,6 +551,12 @@ __v7_setup: orrlt r10, r10, #1 << 11 @ set bit #11 mcrlt p15, 0, r10, c15, c0, 1 @ write diagnostic register #endif +#ifdef CONFIG_ARM_ERRATA_752520 + cmp r6, #0x29 @ present prior to r2p9 + mrclt p15, 0, r10, c15, c0, 1 @ read diagnostic register + orrlt r10, r10, #1 << 20 @ set bit #20 + mcrlt p15, 0, r10, c15, c0, 1 @ write diagnostic register +#endif 3: mov r10, #0 #ifdef HARVARD_CACHE -- cgit v1.2.3