arm/boot: split load_dtb() from arm_load_kernel()

load_dtb() depends on arm_load_kernel() to figure out place
in RAM where it should be loaded, but it's not required for
arm_load_kernel() to work. Sometimes it's neccesary for
devices added with -device/device_add to be enumerated in
DTB as well, which's lead to [1] and surrounding commits to
add 2 more machine_done notifiers with non obvious ordering
to make dynamic sysbus devices initialization happen in
the right order.

However instead of moving whole arm_load_kernel() in to
machine_done, it's sufficient to move only load_dtb() into
virt_machine_done() notifier and remove ArmLoadKernelNotifier/
/PlatformBusFDTNotifierParams notifiers, which saves us ~90LOC
and simplifies code flow quite a bit.
Later would allow to consolidate DTB generation within one
function for 'mach-virt' board and make it reentrant so it
could generate updated DTB in device hotplug secenarios.

While at it rename load_dtb() to arm_load_dtb() since it's
public now.

Add additional field skip_dtb_autoload to struct arm_boot_info
to allow manual DTB load later in mach-virt and to avoid touching
all other boards to explicitly call arm_load_dtb().

 1) (ac9d32e hw/arm/boot: arm_load_kernel implemented as a machine init done notifier)

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 1525691524-32265-4-git-send-email-imammedo@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 34 insertions, 11 deletions

diff --git a/include/hw/arm/arm.h b/include/hw/arm/arm.h
index ce769bde6a..70fa2287e2 100644
--- a/include/hw/arm/arm.h
+++ b/include/hw/arm/arm.h
@@ -39,15 +39,6 @@ DeviceState *armv7m_init(MemoryRegion *system_memory, int mem_size, int num_irq,
  */
 void armv7m_load_kernel(ARMCPU *cpu, const char *kernel_filename, int mem_size);
 
-/*
- * struct used as a parameter of the arm_load_kernel machine init
- * done notifier
- */
-typedef struct {
-    Notifier notifier; /* actual notifier */
-    ARMCPU *cpu; /* handle to the first cpu object */
-} ArmLoadKernelNotifier;
-
 /* arm_boot.c */
 struct arm_boot_info {
     uint64_t ram_size;
@@ -56,6 +47,13 @@ struct arm_boot_info {
     const char *initrd_filename;
     const char *dtb_filename;
     hwaddr loader_start;
+    hwaddr dtb_start;
+    hwaddr dtb_limit;
+    /* If set to True, arm_load_kernel() will not load DTB.
+     * It allows board to load DTB manually later.
+     * (default: False)
+     */
+    bool skip_dtb_autoload;
     /* multicore boards that use the default secondary core boot functions
      * need to put the address of the secondary boot code, the boot reg,
      * and the GIC address in the next 3 values, respectively. boards that
@@ -94,8 +92,6 @@ struct arm_boot_info {
      * the user it should implement this hook.
      */
     void (*modify_dtb)(const struct arm_boot_info *info, void *fdt);
-    /* machine init done notifier executing arm_load_dtb */
-    ArmLoadKernelNotifier load_kernel_notifier;
     /* Used internally by arm_boot.c */
     int is_linux;
     hwaddr initrd_start;
@@ -143,6 +139,33 @@ struct arm_boot_info {
  */
 void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info);
 
+AddressSpace *arm_boot_address_space(ARMCPU *cpu,
+                                     const struct arm_boot_info *info);
+
+/**
+ * arm_load_dtb() - load a device tree binary image into memory
+ * @addr:       the address to load the image at
+ * @binfo:      struct describing the boot environment
+ * @addr_limit: upper limit of the available memory area at @addr
+ * @as:         address space to load image to
+ *
+ * Load a device tree supplied by the machine or by the user  with the
+ * '-dtb' command line option, and put it at offset @addr in target
+ * memory.
+ *
+ * If @addr_limit contains a meaningful value (i.e., it is strictly greater
+ * than @addr), the device tree is only loaded if its size does not exceed
+ * the limit.
+ *
+ * Returns: the size of the device tree image on success,
+ *          0 if the image size exceeds the limit,
+ *          -1 on errors.
+ *
+ * Note: Must not be called unless have_dtb(binfo) is true.
+ */
+int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
+                 hwaddr addr_limit, AddressSpace *as);
+
 /* Write a secure board setup routine with a dummy handler for SMCs */
 void arm_write_secure_board_setup_dummy_smc(ARMCPU *cpu,
                                             const struct arm_boot_info *info,