fw_cfg: remove offset argument from callback prototype

Read callbacks are now only invoked at item selection, before any
data is read. As such, the value of the offset argument passed to
the callback will always be 0. Also, the two callback instances
currently in use both leave their offset argument unused.

This patch removes the offset argument from the fw_cfg read callback
prototype, and from the currently available instances. The unused
(write) callback prototype is also removed (write support was removed
earlier, in commit 023e3148).

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Marc Marí <markmb@redhat.com>
Signed-off-by: NGabriel Somlo <somlo@cmu.edu>
Reviewed-by: NLaszlo Ersek <lersek@redhat.com>
Message-id: 1446733972-1602-4-git-send-email-somlo@cmu.edu
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

hw/arm/virt-acpi-build.c

@@ -631,7 +631,7 @@ static void acpi_ram_update(MemoryRegion *mr, GArray *data)
     memory_region_set_dirty(mr, 0, size);
 }
 
-static void virt_acpi_build_update(void *build_opaque, uint32_t offset)
+static void virt_acpi_build_update(void *build_opaque)
 {
     AcpiBuildState *build_state = build_opaque;
     AcpiBuildTables tables;

hw/i386/acpi-build.c

@@ -1818,7 +1818,7 @@ static void acpi_ram_update(MemoryRegion *mr, GArray *data)
     memory_region_set_dirty(mr, 0, size);
 }
 
-static void acpi_build_update(void *build_opaque, uint32_t offset)
+static void acpi_build_update(void *build_opaque)
 {
     AcpiBuildState *build_state = build_opaque;
     AcpiBuildTables tables;

hw/nvram/fw_cfg.c

@@ -266,7 +266,7 @@ static int fw_cfg_select(FWCfgState *s, uint16_t key)
         arch = !!(key & FW_CFG_ARCH_LOCAL);
         e = &s->entries[arch][key & FW_CFG_ENTRY_MASK];
         if (e->read_callback) {
-            e->read_callback(e->callback_opaque, s->cur_offset);
+            e->read_callback(e->callback_opaque);
         }
     }
 

include/hw/nvram/fw_cfg.h

@@ -70,8 +70,7 @@ typedef struct FWCfgDmaAccess {
     uint64_t address;
 } QEMU_PACKED FWCfgDmaAccess;
 
-typedef void (*FWCfgCallback)(void *opaque, uint8_t *data);
-typedef void (*FWCfgReadCallback)(void *opaque, uint32_t offset);
+typedef void (*FWCfgReadCallback)(void *opaque);
 
 /**
  * fw_cfg_add_bytes: