or1k: Fix compiler warnings

In my build the below are treated as error now and causing failures.  I
have described the fixes of each warning below.

In newlib/libc/sys/or1k/mlock.c:

      CC       libc/sys/or1k/libc_a-mlock.o
    newlib/libc/sys/or1k/mlock.c: In function ‘__malloc_lock’:
    newlib/libc/sys/or1k/mlock.c:56:19: warning: implicit declaration of function ‘or1k_critical_begin’ [-Wimplicit-function-declaration]
       56 |         restore = or1k_critical_begin();
	  |                   ^~~~~~~~~~~~~~~~~~~
    newlib/libc/sys/or1k/mlock.c: In function ‘__malloc_unlock’:
    newlib/libc/sys/or1k/mlock.c:93:17: warning: implicit declaration of function ‘or1k_critical_end’ [-Wimplicit-function-declaration]
       93 |                 or1k_critical_end(restore);
	  |                 ^~~~~~~~~~~~~~~~~

This patch adds prototypes for functions or1k_critical_begin and
or1k_critical_end to suppress the warning, inline with what we do for
or1k_sync_cas.

In libgloss/or1k/or1k_uart.c:

    libgloss/or1k/or1k_uart.c: In function ‘or1k_uart_set_read_cb’:
    libgloss/or1k/or1k_uart.c:163:25: warning: passing argument 2 of ‘or1k_interrupt_handler_add’ from incompatible pointer type [-Wincompatible-pointer-types]
      163 |                         _or1k_uart_interrupt_handler, 0);
	  |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
	  |                         |
	  |                         void (*)(uint32_t) {aka void (*)(long unsigned int)}
    In file included from libgloss/or1k/or1k_uart.c:19:
    libgloss/or1k/include/or1k-support.h:97:45: note: expected ‘or1k_interrupt_handler_fptr’ {aka ‘void (*)(void *)’} but argument is of type ‘void (*)(uint32_t)’ {aka ‘void (*)(long unsigned int)’}
       97 |                 or1k_interrupt_handler_fptr handler,
	  |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~

The public API is ‘void (*)(void *)' for our interrupt handlers.  The
function _or1k_uart_interrupt_hander is the internal default
implementation of the uart IRQ handler and it doesn't use the data
argument.

This patch updates the _or1k_uart_interrupt_handler argument type from
uint32_t to void* allowing the function prototype to match the required
prototype.

If we did have a 64-bit implementation it would be an ABI issue. But,
there never has been one, or1k is only 32-bit.

In libgloss/or1k/interrupts.c:

    libgloss/or1k/interrupts.c: In function ‘or1k_interrupt_handler_add’:
    libgloss/or1k/interrupts.c:41:52: warning: assignment to ‘void *’ from ‘long unsigned int’ makes pointer from integer without a cast [-Wint-conversion]
       41 |         _or1k_interrupt_handler_data_ptr_table[id] = (uint32_t) data_ptr;
	  |                                                    ^

The table _or1k_interrupt_handler_data_ptr_table is an array of void*
and data_ptr is void*.  There is no need for the cast so remove it.

In libgloss/or1k/sbrk.c:

    libgloss/or1k/sbrk.c:23:29: warning: initialization of ‘uint32_t’ {aka ‘long unsigned int’} from ‘uint32_t *’ {aka ‘long unsigned int *’} makes integer from pointer without a cast [-Wint-conversion]
       23 | uint32_t _or1k_heap_start = &end;
	  |

This patch adds a cast, which is safe in or1k as the architecture in
32-bit only.  But this code would not be 64-compatible.

Signed-off-by: Stafford Horne <shorne@gmail.com>

libgloss/or1k/interrupts.c

@@ -35,10 +35,10 @@ void or1k_interrupt_handler_add(uint32_t id,
 {
 #ifdef __OR1K_MULTICORE__
 	_or1k_interrupt_handler_table[or1k_coreid()][id] = handler;
-	_or1k_interrupt_handler_data_ptr_table[or1k_coreid()][id] = (uint32_t) data_ptr;
+	_or1k_interrupt_handler_data_ptr_table[or1k_coreid()][id] = data_ptr;
 #else
 	_or1k_interrupt_handler_table[id] = handler;
-	_or1k_interrupt_handler_data_ptr_table[id] = (uint32_t) data_ptr;
+	_or1k_interrupt_handler_data_ptr_table[id] = data_ptr;
 #endif
 }
 

libgloss/or1k/or1k_uart.c

@@ -90,7 +90,7 @@ void (*_or1k_uart_read_cb)(char c);
  * This is the interrupt handler that is registered for the callback
  * function.
  */
-void _or1k_uart_interrupt_handler(uint32_t data)
+void _or1k_uart_interrupt_handler(void *data)
 {
 	uint8_t iir = REG8(IIR);
 

libgloss/or1k/or1k_uart.h

@@ -30,7 +30,7 @@ extern void (*_or1k_uart_read_cb)(char c);
 /**
  * The UART interrupt handler
  */
-void _or1k_uart_interrupt_handler(uint32_t data);
+void _or1k_uart_interrupt_handler(void *data);
 
 /**
  * Initialize UART

libgloss/or1k/sbrk.c

@@ -20,7 +20,7 @@
 #include "include/or1k-support.h"
 
 extern uint32_t	end; /* Set by linker.  */
-uint32_t _or1k_heap_start = &end;
+uint32_t _or1k_heap_start = (uint32_t) &end;
 uint32_t _or1k_heap_end;
 
 void *

newlib/libc/sys/or1k/mlock.c

@@ -38,6 +38,9 @@ volatile uint32_t _or1k_malloc_lock_restore;
 
 extern uint32_t or1k_sync_cas(void *address, uint32_t compare, uint32_t swap);
 
+extern uint32_t or1k_critical_begin();
+extern void or1k_critical_end(uint32_t restore);
+
 /**
  * Recursive lock of the malloc
  */