target/openrisc: Fixes for memory debugging

Commit Message

Stafford Horne March 13, 2017, 3:01 p.m. UTC

When debugging in gdb you might want to inspect instructions in mapped
pages or in exception vectors like 0x800 etc.  This was previously not
possible in qemu since the *get_phys_page_debug() routine only looked
into the data tlb.

Change to fall back to look into instruction tlb and plain physical
pages.

Signed-off-by: Stafford Horne <[e-mail]>
---
 target/openrisc/mmu.c | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

Patch

diff --git a/target/openrisc/mmu.c b/target/openrisc/mmu.c
index 56b11d3..a6d7bcd 100644
--- a/target/openrisc/mmu.c
+++ b/target/openrisc/mmu.c
@@ -124,7 +124,7 @@  static int cpu_openrisc_get_phys_addr(OpenRISCCPU *cpu,
 {
     int ret = TLBRET_MATCH;
 
-    if (rw == 2) {    /* ITLB */
+    if (rw == MMU_INST_FETCH) {    /* ITLB */
        *physical = 0;
         ret = cpu->env.tlb->cpu_openrisc_map_address_code(cpu, physical,
                                                           prot, address, rw);
@@ -221,12 +221,27 @@  hwaddr openrisc_cpu_get_phys_page_debug(CPUState *cs, vaddr addr)
     OpenRISCCPU *cpu = OPENRISC_CPU(cs);
     hwaddr phys_addr;
     int prot;
+    int miss;
 
-    if (cpu_openrisc_get_phys_addr(cpu, &phys_addr, &prot, addr, 0)) {
-        return -1;
+    /* Check memory for any kind of address, since during debug the
+       gdb can ask for anything, check data tlb for address */
+    miss = cpu_openrisc_get_phys_addr(cpu, &phys_addr, &prot, addr, 0);
+
+    /* Check instruction tlb */
+    if (miss) {
+        miss = cpu_openrisc_get_phys_addr(cpu, &phys_addr, &prot, addr, MMU_INST_FETCH);
+    }
+
+    /* Last, fall back to a plain address */
+    if (miss) {
+        miss = cpu_openrisc_get_phys_nommu(cpu, &phys_addr, &prot, addr, 0);
     }
 
-    return phys_addr;
+    if (miss) {
+        return -1;
+    } else {
+        return phys_addr;
+    }
 }
 
 void cpu_openrisc_mmu_init(OpenRISCCPU *cpu)