xnu-4570.1.46.tar.gz

[apple/xnu.git] / pexpert / arm / pe_kprintf.c

diff --git a/pexpert/arm/pe_kprintf.c b/pexpert/arm/pe_kprintf.c
new file mode 100644 (file)
index 0000000..c0ec137
--- /dev/null
+++ b/pexpert/arm/pe_kprintf.c
@@ -0,0 +1,141 @@
+/*
+ * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
+ */
+/*
+ * file: pe_kprintf.c
+ *    arm platform expert debugging output initialization.
+ */
+#include <stdarg.h>
+#include <machine/machine_routines.h>
+#include <pexpert/pexpert.h>
+#include <kern/debug.h>
+#include <kern/simple_lock.h>
+#include <os/log_private.h>
+#include <libkern/section_keywords.h>
+
+/* Globals */
+void            (*PE_kputc) (char c) = 0;
+
+SECURITY_READ_ONLY_LATE(unsigned int)    disable_serial_output = TRUE;
+
+decl_simple_lock_data(static, kprintf_lock)
+
+void
+PE_init_kprintf(boolean_t vm_initialized)
+{
+       unsigned int    boot_arg;
+
+       if (PE_state.initialized == FALSE)
+               panic("Platform Expert not initialized");
+
+       if (!vm_initialized) {
+               simple_lock_init(&kprintf_lock, 0);
+
+               if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
+                       if (boot_arg & DB_KPRT)
+                               disable_serial_output = FALSE;
+
+               if (serial_init())
+                       PE_kputc = serial_putc;
+               else
+                       PE_kputc = cnputc;
+       }
+}
+
+#ifdef MP_DEBUG
+static void 
+_kprintf(const char *format,...)
+{
+       va_list         listp;
+
+       va_start(listp, format);
+       _doprnt_log(format, &listp, PE_kputc, 16);
+       va_end(listp);
+}
+#define MP_DEBUG_KPRINTF(x...) _kprintf(x)
+#else                          /* MP_DEBUG */
+#define MP_DEBUG_KPRINTF(x...)
+#endif                         /* MP_DEBUG */
+
+#if CONFIG_NO_KPRINTF_STRINGS
+/* Prevent CPP from breaking the definition below */
+#undef kprintf
+#endif
+
+static int      cpu_last_locked = 0;
+
+__attribute__((noinline,not_tail_called))
+void kprintf(const char *fmt,...)
+{
+       va_list         listp;
+       va_list         listp2;
+       boolean_t       state;
+       void           *caller = __builtin_return_address(0);
+
+       if (!disable_serial_output) {
+
+               /*
+                * Spin to get kprintf lock but re-enable interrupts while failing.
+                * This allows interrupts to be handled while waiting but
+                * interrupts are disabled once we have the lock.
+                */
+               state = ml_set_interrupts_enabled(FALSE);
+               while (!simple_lock_try(&kprintf_lock)) {
+                       ml_set_interrupts_enabled(state);
+                       ml_set_interrupts_enabled(FALSE);
+               }
+
+               if (cpu_number() != cpu_last_locked) {
+                       MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
+                       cpu_last_locked = cpu_number();
+               }
+
+               va_start(listp, fmt);
+               va_copy(listp2, listp);
+               _doprnt_log(fmt, &listp, PE_kputc, 16);
+               va_end(listp);
+
+               simple_unlock(&kprintf_lock);
+
+#if INTERRUPT_MASKED_DEBUG
+               /*
+                * kprintf holds interrupts disabled for far too long
+                * and would trip the spin-debugger.  If we are about to reenable
+                * interrupts then clear the timer and avoid panicking on the delay.
+                * Otherwise, let the code that printed with interrupt disabled
+                * take the panic when it reenables interrupts.
+                * Hopefully one day this is fixed so that this workaround is unnecessary.
+                */
+               if (state == TRUE)
+                       ml_spin_debug_clear_self();
+#endif
+               ml_set_interrupts_enabled(state);
+
+               // If interrupts are enabled
+               if (ml_get_interrupts_enabled()) {
+                       os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
+               }
+               va_end(listp2);
+       }
+       else {
+               // If interrupts are enabled
+               if (ml_get_interrupts_enabled()) {
+                       va_start(listp, fmt);
+                       os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp, caller);
+                       va_end(listp);
+               }
+       }
+}
+
+void 
+serial_putc(char c)
+{
+       uart_putc(c);
+}
+
+int 
+serial_getc(void)
+{
+       return uart_getc();
+}
+