target-ppc: Disentangle get_segment()

The poorly named get_segment() function handles most of the address
translation logic for hash-based MMUs.  It has many ugly conditionals on
whether the MMU is 32-bit or 64-bit.

This patch splits the function into 32 and 64-bit versions, using the
switch on mmu_type that's already in the caller
(get_physical_address()) to select the right one.  Most of the
original function remains in mmu_helper.c to support the 6xx software
loaded TLB implementations (cleaning those up is a project for another
day).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 89 insertions, 3 deletions

diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c
index a525bd552f..23eb4801cc 100644
--- a/target-ppc/mmu-hash64.c
+++ b/target-ppc/mmu-hash64.c
@@ -44,7 +44,7 @@
  * SLB handling
  */
 
-ppc_slb_t *slb_lookup(CPUPPCState *env, target_ulong eaddr)
+static ppc_slb_t *slb_lookup(CPUPPCState *env, target_ulong eaddr)
 {
     uint64_t esid_256M, esid_1T;
     int n;
@@ -276,8 +276,8 @@ static int pte64_check(mmu_ctx_t *ctx, target_ulong pte0,
 }
 
 /* PTE table lookup */
-int find_pte64(CPUPPCState *env, mmu_ctx_t *ctx, int h,
-               int rw, int type, int target_page_bits)
+static int find_pte64(CPUPPCState *env, mmu_ctx_t *ctx, int h,
+                      int rw, int type, int target_page_bits)
 {
     hwaddr pteg_off;
     target_ulong pte0, pte1;
@@ -349,3 +349,89 @@ int find_pte64(CPUPPCState *env, mmu_ctx_t *ctx, int h,
     }
     return ret;
 }
+
+int get_segment64(CPUPPCState *env, mmu_ctx_t *ctx,
+                  target_ulong eaddr, int rw, int type)
+{
+    hwaddr hash;
+    target_ulong vsid;
+    int pr, target_page_bits;
+    int ret, ret2;
+
+    pr = msr_pr;
+    ctx->eaddr = eaddr;
+    ppc_slb_t *slb;
+    target_ulong pageaddr;
+    int segment_bits;
+
+    LOG_MMU("Check SLBs\n");
+    slb = slb_lookup(env, eaddr);
+    if (!slb) {
+        return -5;
+    }
+
+    if (slb->vsid & SLB_VSID_B) {
+        vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT_1T;
+        segment_bits = 40;
+    } else {
+        vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT;
+        segment_bits = 28;
+    }
+
+    target_page_bits = (slb->vsid & SLB_VSID_L)
+        ? TARGET_PAGE_BITS_16M : TARGET_PAGE_BITS;
+    ctx->key = !!(pr ? (slb->vsid & SLB_VSID_KP)
+                  : (slb->vsid & SLB_VSID_KS));
+    ctx->nx = !!(slb->vsid & SLB_VSID_N);
+
+    pageaddr = eaddr & ((1ULL << segment_bits)
+                            - (1ULL << target_page_bits));
+    if (slb->vsid & SLB_VSID_B) {
+        hash = vsid ^ (vsid << 25) ^ (pageaddr >> target_page_bits);
+    } else {
+        hash = vsid ^ (pageaddr >> target_page_bits);
+    }
+    /* Only 5 bits of the page index are used in the AVPN */
+    ctx->ptem = (slb->vsid & SLB_VSID_PTEM) |
+        ((pageaddr >> 16) & ((1ULL << segment_bits) - 0x80));
+
+    LOG_MMU("pte segment: key=%d nx %d vsid " TARGET_FMT_lx "\n",
+            ctx->key, ctx->nx, vsid);
+    ret = -1;
+
+    /* Check if instruction fetch is allowed, if needed */
+    if (type != ACCESS_CODE || ctx->nx == 0) {
+        /* Page address translation */
+        LOG_MMU("htab_base " TARGET_FMT_plx " htab_mask " TARGET_FMT_plx
+                " hash " TARGET_FMT_plx "\n",
+                env->htab_base, env->htab_mask, hash);
+        ctx->hash[0] = hash;
+        ctx->hash[1] = ~hash;
+
+        /* Initialize real address with an invalid value */
+        ctx->raddr = (hwaddr)-1ULL;
+        LOG_MMU("0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
+                " vsid=" TARGET_FMT_lx " ptem=" TARGET_FMT_lx
+                " hash=" TARGET_FMT_plx "\n",
+                env->htab_base, env->htab_mask, vsid, ctx->ptem,
+                ctx->hash[0]);
+        /* Primary table lookup */
+        ret = find_pte64(env, ctx, 0, rw, type, target_page_bits);
+        if (ret < 0) {
+            /* Secondary table lookup */
+            LOG_MMU("1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
+                    " vsid=" TARGET_FMT_lx " api=" TARGET_FMT_lx
+                    " hash=" TARGET_FMT_plx "\n", env->htab_base,
+                    env->htab_mask, vsid, ctx->ptem, ctx->hash[1]);
+            ret2 = find_pte64(env, ctx, 1, rw, type, target_page_bits);
+            if (ret2 != -1) {
+                ret = ret2;
+            }
+        }
+    } else {
+        LOG_MMU("No access allowed\n");
+        ret = -3;
+    }
+
+    return ret;
+}