From a0a54d37b4b1d1f55d1e81e8ffc223bb85472fa3 Mon Sep 17 00:00:00 2001
From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Thu, 9 Jun 2011 10:12:41 +0100
Subject: [PATCH] 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>
---
arch/arm/mm/context.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index b6c776ae4039..b0ee9ba3cfab 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -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);
--
GitLab