[Qemu-devel] [5971] target-sh4: Add SH bit handling to TLB

[Qemu-devel] [5971] target-sh4: Add SH bit handling to TLB

[Aurelien Jarno]

Revision: 5971
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=5971
Author:   aurel32
Date:     2008-12-10 17:31:51 +0000 (Wed, 10 Dec 2008)

Log Message:
-----------
target-sh4: Add SH bit handling to TLB

This patch adds SH bit handling to sh4's TLB, which is a part of MMU
functionality that had not been implemented in qemu.

Additionally, increment_urc() call in cpu_load_tlb() is deleted, because
the specification explicitly says that URC is not incremented by an LDTLB
instruction (at Section 3 of SH7751 Hardware manual(REJ09B0370-0400)).
Even though URC is not needed to be strictly same as HW because it is a
random number, this condition is not negligible.

Signed-off-by: Takashi YOSHII <takasi-y@ops.dti.ne.jp>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

Modified Paths:
--------------
    trunk/target-sh4/helper.c

Modified: trunk/target-sh4/helper.c
===================================================================
--- trunk/target-sh4/helper.c	2008-12-10 17:31:43 UTC (rev 5970)
+++ trunk/target-sh4/helper.c	2008-12-10 17:31:51 UTC (rev 5971)
@@ -255,7 +255,7 @@
     for (i = 0; i < nbtlb; i++) {
 	if (!entries[i].v)
 	    continue;		/* Invalid entry */
-	if (use_asid && entries[i].asid != asid)
+	if (!entries[i].sh && use_asid && entries[i].asid != asid)
 	    continue;		/* Bad ASID */
 #if 0
 	switch (entries[i].sz) {
@@ -538,9 +538,6 @@
 	}
     }
 
-    /* per utlb access cannot implemented. */
-    increment_urc(env);
-
     /* Take values into cpu status from registers. */
     entry->asid = (uint8_t)cpu_pteh_asid(env->pteh);
     entry->vpn  = cpu_pteh_vpn(env->pteh);
@@ -581,6 +578,7 @@
     uint8_t d = (uint8_t)((mem_value & 0x00000200) >> 9);
     uint8_t v = (uint8_t)((mem_value & 0x00000100) >> 8);
     uint8_t asid = (uint8_t)(mem_value & 0x000000ff);
+    int use_asid = (s->mmucr & MMUCR_SV) == 0 || (s->sr & SR_MD) == 0;
 
     if (associate) {
         int i;
@@ -593,7 +591,8 @@
             if (!entry->v)
 	        continue;
 
-            if (entry->vpn == vpn && entry->asid == asid) {
+            if (entry->vpn == vpn
+                && (!use_asid || entry->asid == asid || entry->sh)) {
 	        if (utlb_match_entry) {
 		    /* Multiple TLB Exception */
 		    s->exception_index = 0x140;
@@ -612,7 +611,8 @@
 	/* search ITLB */
 	for (i = 0; i < ITLB_SIZE; i++) {
             tlb_t * entry = &s->itlb[i];
-            if (entry->vpn == vpn && entry->asid == asid) {
+            if (entry->vpn == vpn
+                && (!use_asid || entry->asid == asid || entry->sh)) {
 	        if (entry->v && !v)
 		    needs_tlb_flush = 1;
 	        if (utlb_match_entry)