Re: [Qemu-devel] [PATCH 6/6] pci host: make pci_data_{write, read}() get PCIConfigAddress.

["Michael S. Tsirkin" <mst@redhat.com>]

Guys, I was wondering whether the following helper function will be
helpful, as a lot of common code seems to be around identical b/w/l
callbacks.  Comments?

diff --git a/cpu-common.h b/cpu-common.h
index 0ec9b72..be7e992 100644
--- a/cpu-common.h
+++ b/cpu-common.h
@@ -42,6 +42,24 @@ int cpu_register_io_memory(CPUReadMemoryFunc * const *mem_read,
                            void *opaque);
 void cpu_unregister_io_memory(int table_address);
 
+typedef struct CpuIoMemoryHandler CpuIoMemoryHandler;
+/* len is guaranteed to be one of 1, 2 or 4 and does not need
+ * to be range checked. */
+typedef void CpuWriteMemorySimple(CpuIoMemoryHandler *,
+                                  target_phys_addr_t addr,
+                                  uint32_t value, int len);
+typedef uint32_t CpuReadMemorySimple(CpuIoMemoryHandler *,
+                                     target_phys_addr_t addr, int len);
+
+struct CpuIoMemoryHandler {
+    CpuWriteMemorySimple *write;
+    CpuReadMemorySimple *read;
+};
+
+/* Helper routine for when we want to use a single routine with
+ * length instead. */
+int cpu_register_io_memory_simple(struct CpuIoMemoryHandler *);
+
 void cpu_physical_memory_rw(target_phys_addr_t addr, uint8_t *buf,
                             int len, int is_write);
 static inline void cpu_physical_memory_read(target_phys_addr_t addr,
diff --git a/exec.c b/exec.c
index 8a1c08e..cc0bf43 100644
--- a/exec.c
+++ b/exec.c
@@ -3065,6 +3065,67 @@ void cpu_unregister_io_memory(int io_table_address)
     io_mem_used[io_index] = 0;
 }
 
+static void cpu_io_memory_simple_writeb(void *opaque, target_phys_addr_t addr,
+                                        uint32_t value)
+{
+    struct CpuIoMemoryHandler *handler = opaque;
+    handler->write(handler, addr, value, 1);
+}
+
+static uint32_t cpu_io_memory_simple_readb(void *opaque,
+                                           target_phys_addr_t addr)
+{
+    struct CpuIoMemoryHandler *handler = opaque;
+    return handler->read(handler, addr, 1);
+}
+
+static void cpu_io_memory_simple_writew(void *opaque, target_phys_addr_t addr,
+                                        uint32_t value)
+{
+    struct CpuIoMemoryHandler *handler = opaque;
+    handler->write(handler, addr, value, 2);
+}
+
+static uint32_t cpu_io_memory_simple_readw(void *opaque,
+                                           target_phys_addr_t addr)
+{
+    struct CpuIoMemoryHandler *handler = opaque;
+    return handler->read(handler, addr, 2);
+}
+
+static void cpu_io_memory_simple_writel(void *opaque, target_phys_addr_t addr,
+                                        uint32_t value)
+{
+    struct CpuIoMemoryHandler *handler = opaque;
+    handler->write(handler, addr, value, 4);
+}
+
+static uint32_t cpu_io_memory_simple_readl(void *opaque,
+                                           target_phys_addr_t addr)
+{
+    struct CpuIoMemoryHandler *handler = opaque;
+    return handler->read(handler, addr, 4);
+}
+
+static CPUWriteMemoryFunc * const cpu_io_memory_simple_write[] = {
+    &cpu_io_memory_simple_writeb,
+    &cpu_io_memory_simple_writew,
+    &cpu_io_memory_simple_writel,
+};
+
+static CPUReadMemoryFunc * const cpu_io_memory_simple_read[] = {
+    &cpu_io_memory_simple_readb,
+    &cpu_io_memory_simple_readw,
+    &cpu_io_memory_simple_readl,
+};
+
+int cpu_register_io_memory_simple(struct CPUIoMemoryHandler *handler)
+{
+    return cpu_register_io_memory(cpu_io_memory_simple_read,
+                                  cpu_io_memory_simple_write,
+                                  handler);
+}
+
 static void io_mem_init(void)
 {
     int i;