[PATCH 3/4] target/arm: Add new 's1_is_el0' argument to get_phys_addr_lpae()

[Peter Maydell <peter.maydell@linaro.org>]

For ARMv8.2-TTS2UXN, the stage 2 page table walk wants to know
whether the stage 1 access is for EL0 or not, because whether
exec permission is given can depend on whether this is an EL0
or EL1 access. Add a new argument to get_phys_addr_lpae() so
the call sites can pass this information in.

Since get_phys_addr_lpae() doesn't already have a doc comment,
add one so we have a place to put the documentation of the
semantics of the new s1_is_el0 argument.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/helper.c | 29 ++++++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/target/arm/helper.c b/target/arm/helper.c
index 25439bf6fd9..47a175b8e9d 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -41,6 +41,7 @@
 
 static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address,
                                MMUAccessType access_type, ARMMMUIdx mmu_idx,
+                               bool s1_is_el0,
                                hwaddr *phys_ptr, MemTxAttrs *txattrs, int *prot,
                                target_ulong *page_size_ptr,
                                ARMMMUFaultInfo *fi, ARMCacheAttrs *cacheattrs);
@@ -10036,6 +10037,7 @@ static hwaddr S1_ptw_translate(CPUARMState *env, ARMMMUIdx mmu_idx,
         }
 
         ret = get_phys_addr_lpae(env, addr, MMU_DATA_LOAD, ARMMMUIdx_Stage2,
+                                 false,
                                  &s2pa, &txattrs, &s2prot, &s2size, fi,
                                  pcacheattrs);
         if (ret) {
@@ -10638,8 +10640,32 @@ static ARMVAParameters aa32_va_parameters(CPUARMState *env, uint32_t va,
     };
 }
 
+/**
+ * get_phys_addr_lpae: perform one stage of page table walk, LPAE format
+ *
+ * Returns false if the translation was successful. Otherwise, phys_ptr, attrs,
+ * prot and page_size may not be filled in, and the populated fsr value provides
+ * information on why the translation aborted, in the format of a long-format
+ * DFSR/IFSR fault register, with the following caveats:
+ *  * the WnR bit is never set (the caller must do this).
+ *
+ * @env: CPUARMState
+ * @address: virtual address to get physical address for
+ * @access_type: MMU_DATA_LOAD, MMU_DATA_STORE or MMU_INST_FETCH
+ * @mmu_idx: MMU index indicating required translation regime
+ * @s1_is_el0: if @mmu_idx is ARMMMUIdx_Stage2 (so this is a stage 2 page table
+ *             walk), must be true if this is stage 2 of a stage 1+2 walk for an
+ *             EL0 access). If @mmu_idx is anything else, @s1_is_el0 is ignored.
+ * @phys_ptr: set to the physical address corresponding to the virtual address
+ * @attrs: set to the memory transaction attributes to use
+ * @prot: set to the permissions for the page containing phys_ptr
+ * @page_size_ptr: set to the size of the page containing phys_ptr
+ * @fi: set to fault info if the translation fails
+ * @cacheattrs: (if non-NULL) set to the cacheability/shareability attributes
+ */
 static bool get_phys_addr_lpae(CPUARMState *env, target_ulong address,
                                MMUAccessType access_type, ARMMMUIdx mmu_idx,
+                               bool s1_is_el0,
                                hwaddr *phys_ptr, MemTxAttrs *txattrs, int *prot,
                                target_ulong *page_size_ptr,
                                ARMMMUFaultInfo *fi, ARMCacheAttrs *cacheattrs)
@@ -11736,6 +11762,7 @@ bool get_phys_addr(CPUARMState *env, target_ulong address,
 
             /* S1 is done. Now do S2 translation.  */
             ret = get_phys_addr_lpae(env, ipa, access_type, ARMMMUIdx_Stage2,
+                                     mmu_idx == ARMMMUIdx_E10_0,
                                      phys_ptr, attrs, &s2_prot,
                                      page_size, fi,
                                      cacheattrs != NULL ? &cacheattrs2 : NULL);
@@ -11860,7 +11887,7 @@ bool get_phys_addr(CPUARMState *env, target_ulong address,
     }
 
     if (regime_using_lpae_format(env, mmu_idx)) {
-        return get_phys_addr_lpae(env, address, access_type, mmu_idx,
+        return get_phys_addr_lpae(env, address, access_type, mmu_idx, false,
                                   phys_ptr, attrs, prot, page_size,
                                   fi, cacheattrs);
     } else if (regime_sctlr(env, mmu_idx) & SCTLR_XP) {
-- 
2.20.1