[Qemu-block] [PATCH v4 1/4] i386/pc: expose identifying the floppy controller

[Roman Kagan]

Factor out and expose the function to locate the floppy controller in
the system.
It will be useful when dynamically populating the relevant objects in
the ACPI tables.

Signed-off-by: Roman Kagan <address@hidden>
Cc: "Michael S. Tsirkin" <address@hidden>
Cc: Eduardo Habkost <address@hidden>
Cc: Igor Mammedov <address@hidden>
Cc: John Snow <address@hidden>
Cc: Kevin Wolf <address@hidden>
Cc: Paolo Bonzini <address@hidden>
Cc: Richard Henderson <address@hidden>
Cc: address@hidden
Cc: address@hidden
---
changes since v3:
 - split out into a separate patch to faciliate review

 hw/i386/pc.c         | 44 ++++++++++++++++++++++++++------------------
 include/hw/i386/pc.h |  2 ++
 2 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 459260b..c36b8cf 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -360,6 +360,31 @@ static const char * const fdc_container_path[] = {
     "/unattached", "/peripheral", "/peripheral-anon"
 };
 
+/*
+ * Locate the FDC at IO address 0x3f0, in order to configure the CMOS registers
+ * and ACPI objects.
+ */
+ISADevice *pc_find_fdc0(void)
+{
+    int i;
+    Object *container;
+    CheckFdcState state = { 0 };
+
+    for (i = 0; i < ARRAY_SIZE(fdc_container_path); i++) {
+        container = container_get(qdev_get_machine(), fdc_container_path[i]);
+        object_child_foreach(container, check_fdc, &state);
+    }
+
+    if (state.multiple) {
+        error_report("warning: multiple floppy disk controllers with "
+                     "iobase=0x3f0 have been found;\n"
+                     "the one being picked for CMOS setup might not reflect "
+                     "your intent");
+    }
+
+    return state.floppy;
+}
+
 static void pc_cmos_init_late(void *opaque)
 {
     pc_cmos_init_late_arg *arg = opaque;
@@ -368,8 +393,6 @@ static void pc_cmos_init_late(void *opaque)
     int8_t heads, sectors;
     int val;
     int i, trans;
-    Object *container;
-    CheckFdcState state = { 0 };
 
     val = 0;
     if (ide_get_geometry(arg->idebus[0], 0,
@@ -399,22 +422,7 @@ static void pc_cmos_init_late(void *opaque)
     }
     rtc_set_memory(s, 0x39, val);
 
-    /*
-     * Locate the FDC at IO address 0x3f0, and configure the CMOS registers
-     * accordingly.
-     */
-    for (i = 0; i < ARRAY_SIZE(fdc_container_path); i++) {
-        container = container_get(qdev_get_machine(), fdc_container_path[i]);
-        object_child_foreach(container, check_fdc, &state);
-    }
-
-    if (state.multiple) {
-        error_report("warning: multiple floppy disk controllers with "
-                     "iobase=0x3f0 have been found;\n"
-                     "the one being picked for CMOS setup might not reflect "
-                     "your intent");
-    }
-    pc_cmos_init_floppy(s, state.floppy);
+    pc_cmos_init_floppy(s, pc_find_fdc0());
 
     qemu_unregister_reset(pc_cmos_init_late, opaque);
 }
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index b0d6283..8122229 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -267,6 +267,8 @@ typedef void (*cpu_set_smm_t)(int smm, void *arg);
 
 void ioapic_init_gsi(GSIState *gsi_state, const char *parent_name);
 
+ISADevice *pc_find_fdc0(void);
+
 /* acpi_piix.c */
 
 I2CBus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
-- 
2.5.0