[Qemu-devel] [PATCH 0/2] target-xtensa: implement do_unassigned_access

[Qemu-devel] [PATCH 0/2] target-xtensa: implement do_unassigned_access

[Max Filippov]

Hi,

this series implements do_unassigned_access callback for target-xtensa and
adds default memory access handler for the system I/O region of the XTFPGA
board to retain current behaviour.

Max Filippov (2):
  hw/xtensa: allow reads/writes in the system I/O region
  target-xtensa: implement do_unassigned_access callback

 hw/xtensa/xtfpga.c        | 20 +++++++++++++++++++-
 target-xtensa/cpu-qom.h   |  3 +++
 target-xtensa/cpu.c       |  1 +
 target-xtensa/op_helper.c | 14 ++++++++++++++
 4 files changed, 37 insertions(+), 1 deletion(-)

-- 
1.8.1.4

[Qemu-devel] [PATCH 1/2] hw/xtensa: allow reads/writes in the system I/O region

[Max Filippov]

Ignore writes to unassigned areas of system I/O regison and return 0 for
reads. This makes drivers for unimportant unimplemented hardware blocks
happy.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 hw/xtensa/xtfpga.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/hw/xtensa/xtfpga.c b/hw/xtensa/xtfpga.c
index e5a6bba..2c2f997 100644
--- a/hw/xtensa/xtfpga.c
+++ b/hw/xtensa/xtfpga.c
@@ -162,6 +162,23 @@ static void lx60_reset(void *opaque)
     cpu_reset(CPU(cpu));
 }
 
+static uint64_t lx60_io_read(void *opaque, hwaddr addr,
+        unsigned size)
+{
+    return 0;
+}
+
+static void lx60_io_write(void *opaque, hwaddr addr,
+        uint64_t val, unsigned size)
+{
+}
+
+static const MemoryRegionOps lx60_io_ops = {
+    .read = lx60_io_read,
+    .write = lx60_io_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
 static void lx_init(const LxBoardDesc *board, MachineState *machine)
 {
 #ifdef TARGET_WORDS_BIGENDIAN
@@ -211,7 +228,8 @@ static void lx_init(const LxBoardDesc *board, MachineState *machine)
     memory_region_add_subregion(system_memory, 0, ram);
 
     system_io = g_malloc(sizeof(*system_io));
-    memory_region_init(system_io, NULL, "lx60.io", 224 * 1024 * 1024);
+    memory_region_init_io(system_io, NULL, &lx60_io_ops, NULL, "lx60.io",
+                          224 * 1024 * 1024);
     memory_region_add_subregion(system_memory, 0xf0000000, system_io);
     lx60_fpga_init(system_io, 0x0d020000);
     if (nd_table[0].used) {
-- 
1.8.1.4

[Qemu-devel] [PATCH 2/2] target-xtensa: implement do_unassigned_access callback

[Max Filippov]

Depending on access type raise either InstrPIFDataError or
LoadStorePIFDataError exception.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 target-xtensa/cpu-qom.h   |  3 +++
 target-xtensa/cpu.c       |  1 +
 target-xtensa/op_helper.c | 14 ++++++++++++++
 3 files changed, 18 insertions(+)

diff --git a/target-xtensa/cpu-qom.h b/target-xtensa/cpu-qom.h
index 9de5c6e..2258224 100644
--- a/target-xtensa/cpu-qom.h
+++ b/target-xtensa/cpu-qom.h
@@ -85,6 +85,9 @@ static inline XtensaCPU *xtensa_env_get_cpu(const CPUXtensaState *env)
 
 void xtensa_cpu_do_interrupt(CPUState *cpu);
 bool xtensa_cpu_exec_interrupt(CPUState *cpu, int interrupt_request);
+void xtensa_cpu_do_unassigned_access(CPUState *cpu, hwaddr addr,
+                                     bool is_write, bool is_exec, int opaque,
+                                     unsigned size);
 void xtensa_cpu_dump_state(CPUState *cpu, FILE *f,
                            fprintf_function cpu_fprintf, int flags);
 hwaddr xtensa_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
diff --git a/target-xtensa/cpu.c b/target-xtensa/cpu.c
index 6a5414f..2b75678 100644
--- a/target-xtensa/cpu.c
+++ b/target-xtensa/cpu.c
@@ -151,6 +151,7 @@ static void xtensa_cpu_class_init(ObjectClass *oc, void *data)
 #ifndef CONFIG_USER_ONLY
     cc->do_unaligned_access = xtensa_cpu_do_unaligned_access;
     cc->get_phys_page_debug = xtensa_cpu_get_phys_page_debug;
+    cc->do_unassigned_access = xtensa_cpu_do_unassigned_access;
 #endif
     cc->debug_excp_handler = xtensa_breakpoint_handler;
     dc->vmsd = &vmstate_xtensa_cpu;
diff --git a/target-xtensa/op_helper.c b/target-xtensa/op_helper.c
index 49e8634..be657e6 100644
--- a/target-xtensa/op_helper.c
+++ b/target-xtensa/op_helper.c
@@ -71,6 +71,20 @@ void tlb_fill(CPUState *cs,
     }
 }
 
+void xtensa_cpu_do_unassigned_access(CPUState *cs, hwaddr addr,
+                                     bool is_write, bool is_exec, int opaque,
+                                     unsigned size)
+{
+    XtensaCPU *cpu = XTENSA_CPU(cs);
+    CPUXtensaState *env = &cpu->env;
+
+    HELPER(exception_cause_vaddr)(env, env->pc,
+                                  is_exec ?
+                                  INSTR_PIF_ADDR_ERROR_CAUSE :
+                                  LOAD_STORE_PIF_ADDR_ERROR_CAUSE,
+                                  is_exec ? addr : cs->mem_io_vaddr);
+}
+
 static void tb_invalidate_virtual_addr(CPUXtensaState *env, uint32_t vaddr)
 {
     uint32_t paddr;
-- 
1.8.1.4