OMAP2430 SDP boot broken after Linus' rmk merge

[Paul Walmsley]

Tonight I put on a Jon Hopkins album, in recollection of my UK ARM Linux 
colleagues perhaps, and started testing, and eventually wound up with this 
one:

commit 621a0147d5c921f4cc33636ccd0602ad5d7cbfbc
Author: Will Deacon <will.deacon at arm.com>
Date:   Wed Jun 12 12:25:56 2013 +0100

    ARM: 7757/1: mm: don't flush icache in switch_mm with hardware broadcasting
    
    When scheduling an mm on a CPU where it hasn't previously been used, we
    flush the icache on that CPU so that any code loaded previously on
    a different core can be safely executed.
    
    For cores with hardware broadcasting of cache maintenance operations,
    this is clearly unnecessary, since the inner-shareable invalidation in
    __sync_icache_dcache will affect all CPUs.
    
    This patch conditionalises the icache flush in switch_mm based on
    cache_ops_need_broadcast().
    
    Acked-by: Catalin Marinas <catalin.marinas at arm.com>
    Reported-by: Albin Tonnerre <albin.tonnerre at arm.com>
    Signed-off-by: Will Deacon <will.deacon at arm.com>
    Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>

...

v3.11-rc2 boots with it reverted.  What also works is v3.11-rc2 with the 
below patch applied.

Would be pleased to boot-test anything you'd care to send my way, as long 
as you can tolerate response latency jitter.


- Paul

diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h
index b5792b7..8dfb295 100644
--- a/arch/arm/include/asm/mmu_context.h
+++ b/arch/arm/include/asm/mmu_context.h
@@ -112,7 +112,7 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	 * so check for possible thread migration and invalidate the I-cache
 	 * if we're new to this CPU.
 	 */
-	if (cache_ops_need_broadcast() &&
+	if (1 &&
 	    !cpumask_empty(mm_cpumask(next)) &&
 	    !cpumask_test_cpu(cpu, mm_cpumask(next)))
 		__flush_icache_all();