[Qemu-ppc] [PATCH 31/32] mmu-hash64: Don't use full ppc_hash64_translate() path for get_phys_page_debug()

[David Gibson]

Currently the mmu-hash64 version of get_phys_page_debug() uses the same
ppc64_hash64_translate() function to do the translation logic as the normal
mm fault handler code.

That sounds like a good idea, but has some complications. The debug path
doesn't need, or even want some parts of the full translation path, like
pte permissions checking.  Furthermore, the pte flags update included in
the normal path means that the debug call is not quite side effect free.

This patch, therefore, reimplements get_phys_page_debug as the minimal
required subset of the full translation path.

Signed-off-by: David Gibson <address@hidden>
---
 target-ppc/mmu-hash64.c |   19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index 848440c..3f68933 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -454,13 +454,26 @@ static int ppc_hash64_translate(CPUPPCState *env, struct 
mmu_ctx_hash64 *ctx,
 
 hwaddr ppc_hash64_get_phys_page_debug(CPUPPCState *env, target_ulong addr)
 {
-    struct mmu_ctx_hash64 ctx;
+    ppc_slb_t *slb;
+    hwaddr pte_offset;
+    ppc_hash_pte64_t pte;
+
+    if (msr_dr == 0) {
+        /* In real mode the top 4 effective address bits are ignored */
+        return addr & 0x0FFFFFFFFFFFFFFFULL;
+    }
 
-    if (unlikely(ppc_hash64_translate(env, &ctx, addr, 0) != 0)) {
+    slb = slb_lookup(env, addr);
+    if (!slb) {
+        return -1;
+    }
+
+    pte_offset = ppc_hash64_htab_lookup(env, slb, addr, &pte);
+    if (pte_offset == -1) {
         return -1;
     }
 
-    return ctx.raddr & TARGET_PAGE_MASK;
+    return ppc_hash64_pte_real_address(slb, pte, addr) & TARGET_PAGE_MASK;
 }
 
 int ppc_hash64_handle_mmu_fault(CPUPPCState *env, target_ulong address, int 
rwx,
-- 
1.7.10.4