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-rw-r--r--target/arm/cpu.h24
1 files changed, 23 insertions, 1 deletions
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 5c46c48889..13da5036bc 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -2045,6 +2045,18 @@ static inline bool arm_excp_unmasked(CPUState *cs, unsigned int excp_idx,
* for the accesses done as part of a stage 1 page table walk, rather than
* having to walk the stage 2 page table over and over.)
*
+ * R profile CPUs have an MPU, but can use the same set of MMU indexes
+ * as A profile. They only need to distinguish NS EL0 and NS EL1 (and
+ * NS EL2 if we ever model a Cortex-R52).
+ *
+ * M profile CPUs are rather different as they do not have a true MMU.
+ * They have the following different MMU indexes:
+ * User
+ * Privileged
+ * Execution priority negative (this is like privileged, but the
+ * MPU HFNMIENA bit means that it may have different access permission
+ * check results to normal privileged code, so can't share a TLB).
+ *
* The ARMMMUIdx and the mmu index value used by the core QEMU TLB code
* are not quite the same -- different CPU types (most notably M profile
* vs A/R profile) would like to use MMU indexes with different semantics,
@@ -2080,6 +2092,7 @@ typedef enum ARMMMUIdx {
ARMMMUIdx_S2NS = 6 | ARM_MMU_IDX_A,
ARMMMUIdx_MUser = 0 | ARM_MMU_IDX_M,
ARMMMUIdx_MPriv = 1 | ARM_MMU_IDX_M,
+ ARMMMUIdx_MNegPri = 2 | ARM_MMU_IDX_M,
/* Indexes below here don't have TLBs and are used only for AT system
* instructions or for the first stage of an S12 page table walk.
*/
@@ -2100,6 +2113,7 @@ typedef enum ARMMMUIdxBit {
ARMMMUIdxBit_S2NS = 1 << 6,
ARMMMUIdxBit_MUser = 1 << 0,
ARMMMUIdxBit_MPriv = 1 << 1,
+ ARMMMUIdxBit_MNegPri = 1 << 2,
} ARMMMUIdxBit;
#define MMU_USER_IDX 0
@@ -2125,7 +2139,7 @@ static inline int arm_mmu_idx_to_el(ARMMMUIdx mmu_idx)
case ARM_MMU_IDX_A:
return mmu_idx & 3;
case ARM_MMU_IDX_M:
- return mmu_idx & 1;
+ return mmu_idx == ARMMMUIdx_MUser ? 0 : 1;
default:
g_assert_not_reached();
}
@@ -2139,6 +2153,14 @@ static inline int cpu_mmu_index(CPUARMState *env, bool ifetch)
if (arm_feature(env, ARM_FEATURE_M)) {
ARMMMUIdx mmu_idx = el == 0 ? ARMMMUIdx_MUser : ARMMMUIdx_MPriv;
+ /* Execution priority is negative if FAULTMASK is set or
+ * we're in a HardFault or NMI handler.
+ */
+ if ((env->v7m.exception > 0 && env->v7m.exception <= 3)
+ || env->daif & PSTATE_F) {
+ return arm_to_core_mmu_idx(ARMMMUIdx_MNegPri);
+ }
+
return arm_to_core_mmu_idx(mmu_idx);
}