[Xen-devel] [PATCH] xen: arm: context switch the aux memory attribute registers

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

We appear to have somehow missed these. Linux doesn't actually use them and
none of the processors I've looked at actually define any bits in them (so
they are UNK/SBZP) but it is good form to context switch them anyway.

Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
---
 xen/arch/arm/domain.c        |    6 ++++++
 xen/include/asm-arm/cpregs.h |    2 ++
 xen/include/asm-arm/domain.h |    2 ++
 3 files changed, 10 insertions(+)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 4099e88..124cccf 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -98,8 +98,11 @@ static void ctxt_switch_from(struct vcpu *p)
 #if defined(CONFIG_ARM_32)
     p->arch.mair0 = READ_CP32(MAIR0);
     p->arch.mair1 = READ_CP32(MAIR1);
+    p->arch.amair0 = READ_CP32(AMAIR0);
+    p->arch.amair1 = READ_CP32(AMAIR1);
 #else
     p->arch.mair = READ_SYSREG64(MAIR_EL1);
+    p->arch.amair = READ_SYSREG64(AMAIR_EL1);
 #endif
 
     /* Fault Status */
@@ -177,8 +180,11 @@ static void ctxt_switch_to(struct vcpu *n)
 #if defined(CONFIG_ARM_32)
     WRITE_CP32(n->arch.mair0, MAIR0);
     WRITE_CP32(n->arch.mair1, MAIR1);
+    WRITE_CP32(n->arch.amair0, AMAIR0);
+    WRITE_CP32(n->arch.amair1, AMAIR1);
 #elif defined(CONFIG_ARM_64)
     WRITE_SYSREG64(n->arch.mair, MAIR_EL1);
+    WRITE_SYSREG64(n->arch.amair, AMAIR_EL1);
 #endif
     isb();
 
diff --git a/xen/include/asm-arm/cpregs.h b/xen/include/asm-arm/cpregs.h
index 29cd9d7..dcdbe47 100644
--- a/xen/include/asm-arm/cpregs.h
+++ b/xen/include/asm-arm/cpregs.h
@@ -200,6 +200,8 @@
 #define MAIR1           p15,0,c10,c2,1  /* Memory Attribute Indirection 
Register 1 AKA NMRR */
 #define HMAIR0          p15,4,c10,c2,0  /* Hyp. Memory Attribute Indirection 
Register 0 */
 #define HMAIR1          p15,4,c10,c2,1  /* Hyp. Memory Attribute Indirection 
Register 1 */
+#define AMAIR0          p15,0,c10,c3,0  /* Aux. Memory Attribute Indirection 
Register 0 */
+#define AMAIR1          p15,0,c10,c3,1  /* Aux. Memory Attribute Indirection 
Register 1 */
 
 /* CP15 CR11: DMA Operations for TCM Access */
 
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index e2202a6..bc20a15 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -221,8 +221,10 @@ struct arch_vcpu
     uint64_t par;
 #ifdef CONFIG_ARM_32
     uint32_t mair0, mair1;
+    uint32_t amair0, amair1;
 #else
     uint64_t mair;
+    uint64_t amair;
 #endif
 
     /* Control Registers */
-- 
1.7.10.4


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