[Qemu-devel] [PATCH v6 03/13] register: Add Memory API glue

[Alistair Francis]

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.

This patch also adds the RegisterInfoArray struct, which allows all of
the individual RegisterInfo structs to be grouped into a single memory
region.

Signed-off-by: Peter Crosthwaite <address@hidden>
Signed-off-by: Alistair Francis <address@hidden>
---
V6:
 - Add the memory region later
V5:
 - Convert to using only one memory region

 hw/core/register.c    | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++
 include/hw/register.h | 50 +++++++++++++++++++++++++++++++++++
 2 files changed, 122 insertions(+)

diff --git a/hw/core/register.c b/hw/core/register.c
index 5e6f621..25196e6 100644
--- a/hw/core/register.c
+++ b/hw/core/register.c
@@ -147,3 +147,75 @@ 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)
+{
+    RegisterInfoArray *reg_array = opaque;
+    RegisterInfo *reg = NULL;
+    uint64_t we = ~0;
+    int i, shift = 0;
+
+    for (i = 0; i < reg_array->num_elements; i++) {
+        if (reg_array->r[i]->access->decode.addr == addr) {
+            reg = reg_array->r[i];
+            break;
+        }
+    }
+    assert(reg);
+
+    /* Generate appropriate write enable mask and shift values */
+    if (reg->data_size < size) {
+        we = MAKE_64BIT_MASK(0, reg->data_size * 8);
+        shift = 8 * (be ? reg->data_size - size : 0);
+    } else if (reg->data_size >= size) {
+        we = MAKE_64BIT_MASK(0, size * 8);
+    }
+
+    register_write(reg, value << shift, we << shift, reg_array->prefix,
+                   reg_array->debug);
+}
+
+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)
+{
+    RegisterInfoArray *reg_array = opaque;
+    RegisterInfo *reg = NULL;
+    int i, shift;
+
+    for (i = 0; i < reg_array->num_elements; i++) {
+        if (reg_array->r[i]->access->decode.addr == addr) {
+            reg = reg_array->r[i];
+            break;
+        }
+    }
+    assert(reg);
+
+    shift = 8 * (be ? reg->data_size - size : 0);
+
+    return (register_read(reg, reg_array->prefix, reg_array->debug) >> shift) &
+           MAKE_64BIT_MASK(0, size * 8);
+}
+
+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 07d0616..786707b 100644
--- a/include/hw/register.h
+++ b/include/hw/register.h
@@ -15,6 +15,7 @@
 
 typedef struct RegisterInfo RegisterInfo;
 typedef struct RegisterAccessInfo RegisterAccessInfo;
+typedef struct RegisterInfoArray RegisterInfoArray;
 
 /**
  * Access description for a register that is part of guest accessible device
@@ -51,6 +52,10 @@ struct RegisterAccessInfo {
     void (*post_write)(RegisterInfo *reg, uint64_t val);
 
     uint64_t (*post_read)(RegisterInfo *reg, uint64_t val);
+
+    struct {
+        hwaddr addr;
+    } decode;
 };
 
 /**
@@ -79,6 +84,25 @@ struct RegisterInfo {
 };
 
 /**
+ * This structure is used to group all of the individual registers which are
+ * modeled using the RegisterInfo strucutre.
+ *
+ * @r is an aray containing of all the relevent RegisterInfo structures.
+ *
+ * @num_elements is the number of elements in the array r
+ *
+ * @mem: optional Memory region for the register
+ */
+
+struct RegisterInfoArray {
+    int num_elements;
+    RegisterInfo **r;
+
+    bool debug;
+    const char *prefix;
+};
+
+/**
  * write a value to a register, subject to its restrictions
  * @reg: register to write to
  * @val: value to write
@@ -107,4 +131,30 @@ uint64_t register_read(RegisterInfo *reg, const char* 
prefix, bool debug);
 
 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
-- 
2.7.4