Commit a0a54d37 authored Jun 09, 2011 by Russell King

Revert "ARM: 6944/1: mm: allow ASID 0 to be allocated to tasks"



This reverts commit 45b95235.

Will Deacon reports that:

 In 52af9c6c ("ARM: 6943/1: mm: use TTBR1 instead of reserved context ID")
 I updated the ASID rollover code to use only the kernel page tables
 whilst updating the ASID.

 Unfortunately, the code to restore the user page tables was part of a
 later patch which isn't yet in mainline, so this leaves the code
 quite broken.

We're also in the process of eliminating __ARCH_WANT_INTERRUPTS_ON_CTXSW
from ARM, so lets revert these until we can properly sort out what we're
doing with the context switching.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent 07989b7a

arch/arm/mm/context.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -93,7 +93,7 @@ static void reset_context(void *info)
		return;

		smp_rmb();
		asid = cpu_last_asid + cpu;
		asid = cpu_last_asid + cpu + 1;

		flush_context();
		set_mm_context(mm, asid);
		@@ -143,13 +143,13 @@ void __new_context(struct mm_struct *mm)
		* to start a new version and flush the TLB.
		*/
		if (unlikely((asid & ~ASID_MASK) == 0)) {
		asid = cpu_last_asid + smp_processor_id();
		asid = cpu_last_asid + smp_processor_id() + 1;
		flush_context();
		#ifdef CONFIG_SMP
		smp_wmb();
		smp_call_function(reset_context, NULL, 1);
		#endif
		cpu_last_asid += NR_CPUS - 1;
		cpu_last_asid += NR_CPUS;
		}

		set_mm_context(mm, asid);