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authorLeon Alrae <leon.alrae@imgtec.com>2014-07-07 11:23:58 +0100
committerLeon Alrae <leon.alrae@imgtec.com>2014-11-03 11:48:34 +0000
commit2fb58b73746e2f99ac85e82160277b18b18279be (patch)
treecedded3812b8bd8cf5718c655420673c3a6b6ba7 /target-mips/helper.c
parent9f6bcedba61927438000fb94b0706c22dfb87eaa (diff)
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target-mips: add RI and XI fields to TLB entry
In Revision 3 of the architecture, the RI and XI bits were added to the TLB to enable more secure access of memory pages. These bits (along with the Dirty bit) allow the implementation of read-only, write-only, no-execute access policies for mapped pages. Signed-off-by: Leon Alrae <leon.alrae@imgtec.com> Reviewed-by: Yongbok Kim <yongbok.kim@imgtec.com>
Diffstat (limited to 'target-mips/helper.c')
-rw-r--r--target-mips/helper.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/target-mips/helper.c b/target-mips/helper.c
index 1c9e69d..49187a3 100644
--- a/target-mips/helper.c
+++ b/target-mips/helper.c
@@ -27,6 +27,8 @@
#include "sysemu/kvm.h"
enum {
+ TLBRET_XI = -6,
+ TLBRET_RI = -5,
TLBRET_DIRTY = -4,
TLBRET_INVALID = -3,
TLBRET_NOMATCH = -2,
@@ -85,8 +87,15 @@ int r4k_map_address (CPUMIPSState *env, hwaddr *physical, int *prot,
/* TLB match */
int n = !!(address & mask & ~(mask >> 1));
/* Check access rights */
- if (!(n ? tlb->V1 : tlb->V0))
+ if (!(n ? tlb->V1 : tlb->V0)) {
return TLBRET_INVALID;
+ }
+ if (rw == MMU_INST_FETCH && (n ? tlb->XI1 : tlb->XI0)) {
+ return TLBRET_XI;
+ }
+ if (rw == MMU_DATA_LOAD && (n ? tlb->RI1 : tlb->RI0)) {
+ return TLBRET_RI;
+ }
if (rw != MMU_DATA_STORE || (n ? tlb->D1 : tlb->D0)) {
*physical = tlb->PFN[n] | (address & (mask >> 1));
*prot = PAGE_READ;