grlib: Add ambapp_plb()

Replace the global variable ambapp_plb with a function to allow an automatic on
demand initialization.

5 files changed, 25 insertions, 16 deletions

diff --git a/bsps/riscv/griscv/console/console.c b/bsps/riscv/griscv/console/console.c
index c92be99fdb..c0e19cddfe 100644
--- a/bsps/riscv/griscv/console/console.c
+++ b/bsps/riscv/griscv/console/console.c
@@ -68,7 +68,7 @@ static int find_matching_apbuart(struct ambapp_dev *dev, int index, void *arg)
   /* Get APBUART core frequency, it is assumed that it is the same
    * as Bus frequency where the UART is situated
    */
-  apbuarts[uarts].freq_hz = ambapp_freq_get(&ambapp_plb, dev);
+  apbuarts[uarts].freq_hz = ambapp_freq_get(ambapp_plb(), dev);
   uarts++;
 
   if (uarts >= BSP_NUMBER_OF_TERMIOS_PORTS)
@@ -83,7 +83,7 @@ static void grlib_console_scan_uarts(void)
   memset(apbuarts, 0, sizeof(apbuarts));
 
   /* Find APBUART cores */
-  ambapp_for_each(&ambapp_plb, (OPTIONS_ALL|OPTIONS_APB_SLVS), VENDOR_GAISLER,
+  ambapp_for_each(ambapp_plb(), (OPTIONS_ALL|OPTIONS_APB_SLVS), VENDOR_GAISLER,
                   GAISLER_APBUART, find_matching_apbuart, NULL);
 }
 
diff --git a/bsps/riscv/griscv/console/printk_support.c b/bsps/riscv/griscv/console/printk_support.c
index f8c14692c1..e789924e4f 100644
--- a/bsps/riscv/griscv/console/printk_support.c
+++ b/bsps/riscv/griscv/console/printk_support.c
@@ -64,7 +64,7 @@ static void bsp_debug_uart_init(void)
 
   /* Find APBUART core for System Debug Console */
   i = grlib_debug_uart_index;
-  adev = (void *)ambapp_for_each(&ambapp_plb, (OPTIONS_ALL|OPTIONS_APB_SLVS),
+  adev = (void *)ambapp_for_each(ambapp_plb(), (OPTIONS_ALL|OPTIONS_APB_SLVS),
                                  VENDOR_GAISLER, GAISLER_APBUART,
                                  ambapp_find_by_idx, (void *)&i);
   if (adev) {
diff --git a/bsps/riscv/griscv/include/amba.h b/bsps/riscv/griscv/include/amba.h
index 8833cdfba6..292660d5c1 100644
--- a/bsps/riscv/griscv/include/amba.h
+++ b/bsps/riscv/griscv/include/amba.h
@@ -69,9 +69,6 @@
 extern "C" {
 #endif
 
-/* The AMBA Plug&Play info of the bus that the cpu sits on */
-extern struct ambapp_bus ambapp_plb;
-
 extern uint32_t GRLIB_Cpu_Index;
 extern const unsigned char GRLIB_mp_irq;
 
@@ -89,7 +86,7 @@ static inline uint32_t grlib_up_counter_frequency(void)
    * For simplicity, assume that the interrupt controller uses the processor
    * clock.  This is at least true on the GR740.
    */
-  return ambapp_freq_get(&ambapp_plb, GRLIB_IrqCtrl_Adev);
+  return ambapp_freq_get(ambapp_plb(), GRLIB_IrqCtrl_Adev);
 }
 
 extern rtems_interrupt_lock GRLIB_IrqCtrl_Lock;
diff --git a/bsps/riscv/griscv/start/amba.c b/bsps/riscv/griscv/start/amba.c
index 182f659d69..ffb609dc38 100644
--- a/bsps/riscv/griscv/start/amba.c
+++ b/bsps/riscv/griscv/start/amba.c
@@ -42,7 +42,7 @@ void irqmp_initialize(void)
   struct ambapp_dev *adev;
 
   /* Find GRLIB Interrupt controller */
-  adev = (void *)ambapp_for_each(&ambapp_plb, (OPTIONS_ALL|OPTIONS_APB_SLVS),
+  adev = (void *)ambapp_for_each(ambapp_plb(), (OPTIONS_ALL|OPTIONS_APB_SLVS),
                                  VENDOR_GAISLER, GAISLER_IRQMP,
                                  ambapp_find_by_idx, NULL);
   if (adev != NULL) {
@@ -89,7 +89,7 @@ void gptimer_initialize(void)
   struct ambapp_dev *adev;
 
   /* find GP Timer */
-  adev = (void *)ambapp_for_each(&ambapp_plb, (OPTIONS_ALL|OPTIONS_APB_SLVS),
+  adev = (void *)ambapp_for_each(ambapp_plb(), (OPTIONS_ALL|OPTIONS_APB_SLVS),
                                  VENDOR_GAISLER, GAISLER_GPTIMER,
                                  ambapp_find_by_idx, &grlib_timer_core_index);
   if (adev) {
@@ -98,7 +98,7 @@ void gptimer_initialize(void)
 
     /* Register AMBA Bus Frequency */
     ambapp_freq_init(
-      &ambapp_plb,
+      ambapp_plb(),
       GRLIB_Timer_Adev,
       (GRLIB_Timer_Regs->scaler_reload + 1)
         * GRLIB_GPTIMER_0_FREQUENCY_SET_BY_BOOT_LOADER
diff --git a/bsps/riscv/griscv/start/bspstart.c b/bsps/riscv/griscv/start/bspstart.c
index dd83c80818..26c214caac 100644
--- a/bsps/riscv/griscv/start/bspstart.c
+++ b/bsps/riscv/griscv/start/bspstart.c
@@ -53,14 +53,26 @@ void bsp_start(void)
 #endif
 }
 
-void amba_initialize(void);
-struct ambapp_bus ambapp_plb;
+static struct ambapp_bus ambapp_plb_instance;
 
-void amba_initialize(void)
+struct ambapp_bus *ambapp_plb( void )
 {
-  ambapp_scan(&ambapp_plb, GRLIB_IO_AREA, NULL, NULL);
-  gptimer_initialize();
-  irqmp_initialize();
+  struct ambapp_bus *plb;
+
+  plb = &ambapp_plb_instance;
+
+  if ( plb->root == NULL ) {
+    ambapp_scan( plb, GRLIB_IO_AREA, NULL, NULL );
+    gptimer_initialize();
+    irqmp_initialize();
+  }
+
+  return plb;
+}
+
+static void amba_initialize( void )
+{
+  (void) ambapp_plb();
 }
 
 RTEMS_SYSINIT_ITEM(