Revert "ARM: 6944/1: mm: allow ASID 0 to be allocated to tasks"
This reverts commit 45b95235b0ac86cef2ad4480b0618b8778847479.
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>
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index b6c776a..b0ee9ba 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -93,7 +93,7 @@
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 @@
* 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);