rwhandler: simplified way to register for mem/io

Some users prefer a single callback with length passed as parameter to
using b/w/l callbacks. It would maybe be cleaner to just pass length to
existing callbacks but that's a lot of churn.  So for now add a wrapper.
For convenience use pcibus_t for address so a single callback can be
used for pci io and pci memory.

I did have to resort to preprocessor to reduce code duplication.  It is
however slightly more straightforward, and better contained than what we
had with pci_host_template.h. Again, it would go away if we just passed
len to existing callbacks.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Makefile.target

@@ -46,6 +46,7 @@ all: $(PROGS)
 # cpu emulator library
 libobj-y = exec.o translate-all.o cpu-exec.o translate.o
 libobj-y += tcg/tcg.o
+libobj-y += rwhandler.o
 libobj-$(CONFIG_SOFTFLOAT) += fpu/softfloat.o
 libobj-$(CONFIG_NOSOFTFLOAT) += fpu/softfloat-native.o
 libobj-y += op_helper.o helper.o

rwhandler.c

@@ -0,0 +1,91 @@
+#include "rwhandler.h"
+#include "ioport.h"
+#include "cpu-all.h"
+
+#if !defined(CONFIG_USER_ONLY)
+
+#define RWHANDLER_WRITE(name, len, type) \
+static void name(void *opaque, type addr, uint32_t value) \
+{\
+    struct ReadWriteHandler *handler = opaque;\
+    handler->write(handler, addr, value, len);\
+}
+
+#define RWHANDLER_READ(name, len, type) \
+static uint32_t name(void *opaque, type addr) \
+{ \
+    struct ReadWriteHandler *handler = opaque; \
+    return handler->read(handler, addr, len); \
+}
+
+RWHANDLER_WRITE(cpu_io_memory_simple_writeb, 1, target_phys_addr_t);
+RWHANDLER_READ(cpu_io_memory_simple_readb, 1, target_phys_addr_t);
+RWHANDLER_WRITE(cpu_io_memory_simple_writew, 2, target_phys_addr_t);
+RWHANDLER_READ(cpu_io_memory_simple_readw, 2, target_phys_addr_t);
+RWHANDLER_WRITE(cpu_io_memory_simple_writel, 4, target_phys_addr_t);
+RWHANDLER_READ(cpu_io_memory_simple_readl, 4, target_phys_addr_t);
+
+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 ReadWriteHandler *handler)
+{
+    if (!handler->read || !handler->write) {
+        return -1;
+    }
+    return cpu_register_io_memory(cpu_io_memory_simple_read,
+                                  cpu_io_memory_simple_write,
+                                  handler);
+}
+
+RWHANDLER_WRITE(ioport_simple_writeb, 1, uint32_t);
+RWHANDLER_READ(ioport_simple_readb, 1, uint32_t);
+RWHANDLER_WRITE(ioport_simple_writew, 2, uint32_t);
+RWHANDLER_READ(ioport_simple_readw, 2, uint32_t);
+RWHANDLER_WRITE(ioport_simple_writel, 4, uint32_t);
+RWHANDLER_READ(ioport_simple_readl, 4, uint32_t);
+
+int register_ioport_simple(ReadWriteHandler* handler,
+                           pio_addr_t start, int length, int size)
+{
+    IOPortWriteFunc *write;
+    IOPortReadFunc *read;
+    int r;
+    switch (size) {
+    case 1:
+        write = ioport_simple_writeb;
+        read = ioport_simple_readb;
+        break;
+    case 2:
+        write = ioport_simple_writew;
+        read = ioport_simple_readw;
+        break;
+    default:
+        write = ioport_simple_writel;
+        read = ioport_simple_readl;
+    }
+    if (handler->write) {
+        r = register_ioport_write(start, length, size, write, handler);
+        if (r < 0) {
+            return r;
+        }
+    }
+    if (handler->read) {
+        r = register_ioport_read(start, length, size, read, handler);
+        if (r < 0) {
+            return r;
+        }
+    }
+    return 0;
+}
+
+#endif

rwhandler.h

@@ -0,0 +1,27 @@
+#ifndef READ_WRITE_HANDLER_H
+#define READ_WRITE_HANDLER_H
+
+#include "qemu-common.h"
+#include "ioport.h"
+
+typedef struct ReadWriteHandler ReadWriteHandler;
+
+/* len is guaranteed to be one of 1, 2 or 4, addr is guaranteed to fit in an
+ * appropriate type (io/memory/etc). They do not need to be range checked. */
+typedef void WriteHandlerFunc(ReadWriteHandler *, pcibus_t addr,
+                              uint32_t value, int len);
+typedef uint32_t ReadHandlerFunc(ReadWriteHandler *, pcibus_t addr, int len);
+
+struct ReadWriteHandler {
+    WriteHandlerFunc *write;
+    ReadHandlerFunc *read;
+};
+
+/* Helpers for when we want to use a single routine with length. */
+/* CPU memory handler: both read and write must be present. */
+int cpu_register_io_memory_simple(ReadWriteHandler *);
+/* io port handler: can supply only read or write handlers. */
+int register_ioport_simple(ReadWriteHandler *,
+                           pio_addr_t start, int length, int size);
+
+#endif