[PATCH 11/18] arm/arm64: make mmu_on per cpu

Andrew Jones
2015-02-01T18:35:11Z

We introduced a variable called mmu_on to the mmu implementation
because unit tests may want to run with the mmu off, yet still
call into common code that could lead to {Load,Store}-Exclusive
instructions - which is illegal. So, the mmu_on variable was added
and made query-able (through mmu_enabled()) in order to guard those
paths. But, mmu_on is really a per cpu concept, so for smp we need
to change it. As it's just a bool, we can easily make it per cpu by
changing it into a cpumask. We rename it more appropriately too.

Signed-off-by: Andrew Jones <drjones@redhat.com>
---
lib/arm/asm/mmu-api.h | 1 +
lib/arm/mmu.c | 15 ++++++++++++---
2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/lib/arm/asm/mmu-api.h b/lib/arm/asm/mmu-api.h
index f2511e3dc7dee..68dc707d67241 100644
--- a/lib/arm/asm/mmu-api.h
+++ b/lib/arm/asm/mmu-api.h
@@ -2,6 +2,7 @@
#define __ASMARM_MMU_API_H_
extern pgd_t *mmu_idmap;
extern bool mmu_enabled(void);
+extern void mmu_set_enabled(void);
extern void mmu_enable(pgd_t *pgtable);
extern void mmu_enable_idmap(void);
extern void mmu_init_io_sect(pgd_t *pgtable, unsigned long virt_offset);
diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
index 1c024538663ce..732000a8eb088 100644
--- a/lib/arm/mmu.c
+++ b/lib/arm/mmu.c
@@ -6,16 +6,25 @@
* This work is licensed under the terms of the GNU LGPL, version 2.
*/
#include <asm/setup.h>
+#include <asm/thread_info.h>
+#include <asm/cpumask.h>
#include <asm/mmu.h>

extern unsigned long etext;

pgd_t *mmu_idmap;

-static bool mmu_on;
+static cpumask_t mmu_enabled_cpumask;
bool mmu_enabled(void)
{
- return mmu_on;
+ struct thread_info *ti = current_thread_info();
+ return cpumask_test_cpu(ti->cpu, &mmu_enabled_cpumask);
+}
+
+void mmu_set_enabled(void)
+{
+ struct thread_info *ti = current_thread_info();
+ cpumask_set_cpu(ti->cpu, &mmu_enabled_cpumask);
}

extern void asm_mmu_enable(phys_addr_t pgtable);
@@ -23,7 +32,7 @@ void mmu_enable(pgd_t *pgtable)
{
asm_mmu_enable(__pa(pgtable));
flush_tlb_all();
- mmu_on = true;
+ mmu_set_enabled();
}

void mmu_set_range_ptes(pgd_t *pgtable, unsigned long virt_offset,
--
1.9.3