[Qemu-devel] [PATCH v1 02/15] register: Add Memory API glue

[Alistair Francis <alistair.francis@xilinx.com>]

From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>

Add memory io handlers that glue the register API to the memory API.
Just translation functions at this stage. Although it does allow for
devices to be created without all-in-one mmio r/w handlers.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
---
changed from v2:
Added fast path to register_write_memory to skip endianness bitbashing

 hw/core/register.c    |   48 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/register.h |   30 ++++++++++++++++++++++++++++++
 2 files changed, 78 insertions(+), 0 deletions(-)

diff --git a/hw/core/register.c b/hw/core/register.c
index 02a4376..ca10cff 100644
--- a/hw/core/register.c
+++ b/hw/core/register.c
@@ -184,3 +184,51 @@ void register_reset(RegisterInfo *reg)
 
     register_write_val(reg, reg->access->reset);
 }
+
+static inline void register_write_memory(void *opaque, hwaddr addr,
+                                         uint64_t value, unsigned size, bool be)
+{
+    RegisterInfo *reg = opaque;
+    uint64_t we = ~0;
+    int shift = 0;
+
+    if (reg->data_size != size) {
+        we = (size == 8) ? ~0ull : (1ull << size * 8) - 1;
+        shift = 8 * (be ? reg->data_size - size - addr : addr);
+    }
+
+    assert(size + addr <= reg->data_size);
+    register_write(reg, value << shift, we << shift);
+}
+
+void register_write_memory_be(void *opaque, hwaddr addr, uint64_t value,
+                              unsigned size)
+{
+    register_write_memory(opaque, addr, value, size, true);
+}
+
+
+void register_write_memory_le(void *opaque, hwaddr addr, uint64_t value,
+                              unsigned size)
+{
+    register_write_memory(opaque, addr, value, size, false);
+}
+
+static inline uint64_t register_read_memory(void *opaque, hwaddr addr,
+                                            unsigned size, bool be)
+{
+    RegisterInfo *reg = opaque;
+    int shift = 8 * (be ? reg->data_size - size - addr : addr);
+
+    return register_read(reg) >> shift;
+}
+
+uint64_t register_read_memory_be(void *opaque, hwaddr addr, unsigned size)
+{
+    return register_read_memory(opaque, addr, size, true);
+}
+
+uint64_t register_read_memory_le(void *opaque, hwaddr addr, unsigned size)
+{
+    return register_read_memory(opaque, addr, size, false);
+}
diff --git a/include/hw/register.h b/include/hw/register.h
index 249f458..a3c41db 100644
--- a/include/hw/register.h
+++ b/include/hw/register.h
@@ -86,6 +86,8 @@ struct RegisterAccessInfo {
  * @prefix: String prefix for log and debug messages
  *
  * @opaque: Opaque data for the register
+ *
+ * @mem: optional Memory region for the register
  */
 
 struct RegisterInfo {
@@ -103,6 +105,8 @@ struct RegisterInfo {
 
     bool read_lite;
     bool write_lite;
+
+    MemoryRegion mem;
 };
 
 /**
@@ -129,4 +133,30 @@ uint64_t register_read(RegisterInfo *reg);
 
 void register_reset(RegisterInfo *reg);
 
+/**
+ * Memory API MMIO write handler that will write to a Register API register.
+ *  _be for big endian variant and _le for little endian.
+ * @opaque: RegisterInfo to write to
+ * @addr: Address to write
+ * @value: Value to write
+ * @size: Number of bytes to write
+ */
+
+void register_write_memory_be(void *opaque, hwaddr addr, uint64_t value,
+                              unsigned size);
+void register_write_memory_le(void *opaque, hwaddr addr, uint64_t value,
+                              unsigned size);
+
+/**
+ * Memory API MMIO read handler that will read from a Register API register.
+ *  _be for big endian variant and _le for little endian.
+ * @opaque: RegisterInfo to read from
+ * @addr: Address to read
+ * @size: Number of bytes to read
+ * returns: Value read from register
+ */
+
+uint64_t register_read_memory_be(void *opaque, hwaddr addr, unsigned size);
+uint64_t register_read_memory_le(void *opaque, hwaddr addr, unsigned size);
+
 #endif
-- 
1.7.1