target/arm: Remove is_subpage argument to pmsav8_mpu_lookup

This can be made redundant with result->page_size, by moving the basic
set of page_size from get_phys_addr_pmsav8.  We still need to overwrite
page_size when v8m_security_lookup signals a subpage.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220822152741.1617527-11-richard.henderson@linaro.org
[PMM: Update a comment that used to refer to is_subpage]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

3 files changed, 15 insertions, 15 deletions

diff --git a/target/arm/internals.h b/target/arm/internals.h
index 103ae74..f8b22d3 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1152,8 +1152,8 @@ bool get_phys_addr(CPUARMState *env, target_ulong address,
 
 bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
                        MMUAccessType access_type, ARMMMUIdx mmu_idx,
-                       GetPhysAddrResult *result, bool *is_subpage,
-                       ARMMMUFaultInfo *fi, uint32_t *mregion);
+                       GetPhysAddrResult *result, ARMMMUFaultInfo *fi,
+                       uint32_t *mregion);
 
 void arm_log_exception(CPUState *cs);
 
diff --git a/target/arm/m_helper.c b/target/arm/m_helper.c
index 69d4a63..0126399 100644
--- a/target/arm/m_helper.c
+++ b/target/arm/m_helper.c
@@ -2806,11 +2806,10 @@ uint32_t HELPER(v7m_tt)(CPUARMState *env, uint32_t addr, uint32_t op)
     if (arm_current_el(env) != 0 || alt) {
         GetPhysAddrResult res = {};
         ARMMMUFaultInfo fi = {};
-        bool is_subpage;
 
         /* We can ignore the return value as prot is always set */
         pmsav8_mpu_lookup(env, addr, MMU_DATA_LOAD, mmu_idx,
-                          &res, &is_subpage, &fi, &mregion);
+                          &res, &fi, &mregion);
         if (mregion == -1) {
             mrvalid = false;
             mregion = 0;
diff --git a/target/arm/ptw.c b/target/arm/ptw.c
index d689004..bb3c709 100644
--- a/target/arm/ptw.c
+++ b/target/arm/ptw.c
@@ -1701,8 +1701,8 @@ static bool get_phys_addr_pmsav7(CPUARMState *env, uint32_t address,
 
 bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
                        MMUAccessType access_type, ARMMMUIdx mmu_idx,
-                       GetPhysAddrResult *result, bool *is_subpage,
-                       ARMMMUFaultInfo *fi, uint32_t *mregion)
+                       GetPhysAddrResult *result, ARMMMUFaultInfo *fi,
+                       uint32_t *mregion)
 {
     /*
      * Perform a PMSAv8 MPU lookup (without also doing the SAU check
@@ -1710,8 +1710,9 @@ bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
      * mregion is (if not NULL) set to the region number which matched,
      * or -1 if no region number is returned (MPU off, address did not
      * hit a region, address hit in multiple regions).
-     * We set is_subpage to true if the region hit doesn't cover the
-     * entire TARGET_PAGE the address is within.
+     * If the region hit doesn't cover the entire TARGET_PAGE the address
+     * is within, then we set the result page_size to 1 to force the
+     * memory system to use a subpage.
      */
     ARMCPU *cpu = env_archcpu(env);
     bool is_user = regime_is_user(env, mmu_idx);
@@ -1722,7 +1723,7 @@ bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
     uint32_t addr_page_base = address & TARGET_PAGE_MASK;
     uint32_t addr_page_limit = addr_page_base + (TARGET_PAGE_SIZE - 1);
 
-    *is_subpage = false;
+    result->page_size = TARGET_PAGE_SIZE;
     result->phys = address;
     result->prot = 0;
     if (mregion) {
@@ -1774,13 +1775,13 @@ bool pmsav8_mpu_lookup(CPUARMState *env, uint32_t address,
                     ranges_overlap(base, limit - base + 1,
                                    addr_page_base,
                                    TARGET_PAGE_SIZE)) {
-                    *is_subpage = true;
+                    result->page_size = 1;
                 }
                 continue;
             }
 
             if (base > addr_page_base || limit < addr_page_limit) {
-                *is_subpage = true;
+                result->page_size = 1;
             }
 
             if (matchregion != -1) {
@@ -1972,7 +1973,6 @@ static bool get_phys_addr_pmsav8(CPUARMState *env, uint32_t address,
     uint32_t secure = regime_is_secure(env, mmu_idx);
     V8M_SAttributes sattrs = {};
     bool ret;
-    bool mpu_is_subpage;
 
     if (arm_feature(env, ARM_FEATURE_M_SECURITY)) {
         v8m_security_lookup(env, address, access_type, mmu_idx, &sattrs);
@@ -2035,9 +2035,10 @@ static bool get_phys_addr_pmsav8(CPUARMState *env, uint32_t address,
     }
 
     ret = pmsav8_mpu_lookup(env, address, access_type, mmu_idx,
-                            result, &mpu_is_subpage, fi, NULL);
-    result->page_size =
-        sattrs.subpage || mpu_is_subpage ? 1 : TARGET_PAGE_SIZE;
+                            result, fi, NULL);
+    if (sattrs.subpage) {
+        result->page_size = 1;
+    }
     return ret;
 }