[Qemu-devel] [PATCH] PPC: booke206: Check for min/max TLB entry size

[Alexander Graf <agraf@suse.de>]

When setting a TLB entry, we need to check if the TLB we're putting it in
actually supports the given size. According to the 2.06 PowerPC ISA, a
value that's out of range results in the minimum page size for the TLB
to be used.

Signed-off-by: Alexander Graf <agraf@suse.de>

---

v1 -> v2:

  - fix min/max check

diff --git a/target-ppc/op_helper.c b/target-ppc/op_helper.c
index 6339c95..8cd0224 100644
--- a/target-ppc/op_helper.c
+++ b/target-ppc/op_helper.c
@@ -4228,6 +4228,7 @@ void helper_booke206_tlbwe(void)
 {
     uint32_t tlbncfg, tlbn;
     ppcmas_tlb_t *tlb;
+    uint32_t size_tlb, size_min, size_max;
 
     switch (env->spr[SPR_BOOKE_MAS0] & MAS0_WQ_MASK) {
     case MAS0_WQ_ALWAYS:
@@ -4273,6 +4274,16 @@ void helper_booke206_tlbwe(void)
         tlb->mas1 &= ~MAS1_IPROT;
     }
 
+    /* XXX only applies for MAV 1.0 */
+    size_tlb = (tlb->mas1 & MAS1_TSIZE_MASK) >> (MAS1_TSIZE_SHIFT + 1);
+    size_min = (tlbncfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
+    size_max = (tlbncfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
+    if ((size_tlb > size_max) || (size_tlb < size_min)) {
+        /* set to min size */
+        tlb->mas1 &= ~MAS1_TSIZE_MASK;
+        tlb->mas1 |= size_min << (MAS1_TSIZE_SHIFT + 1);
+    }
+
     if (booke206_tlb_to_page_size(env, tlb) == TARGET_PAGE_SIZE) {
         tlb_flush_page(env, tlb->mas2 & MAS2_EPN_MASK);
     } else {