2007-09-05 Daniel Hellstrom <daniel@gaisler.com>

	* include/bsp.h, startup/bspstart.c: LEON2 and LEON3 Data cache
	snooping detection on startup, for drivers. (LEON2,3 are configurable
	processors, they can be with or without DCache snooping. Caches
	without snooping needs the drivers to flush cache or use the sparc
	instruction lda to force cache miss...)

1 files changed, 27 insertions, 0 deletions

diff --git a/c/src/lib/libbsp/sparc/leon3/startup/bspstart.c b/c/src/lib/libbsp/sparc/leon3/startup/bspstart.c
index e863250614..baf1b1cbef 100644
--- a/c/src/lib/libbsp/sparc/leon3/startup/bspstart.c
+++ b/c/src/lib/libbsp/sparc/leon3/startup/bspstart.c
@@ -42,11 +42,36 @@ rtems_cpu_table Cpu_table;
 
 extern uint32_t rdb_start;
 
+/*
+ * Tells us if data cache snooping is available
+ */ 
+
+int CPU_SPARC_HAS_SNOOPING;
+
 void bsp_postdriver_hook(void);
 void bsp_libc_init( void *, uint32_t, int );
 extern void bsp_spurious_initialize();
 
 /*
+ * set_snooping
+ * 
+ * Read the data cache configuration register to determine if
+ * bus snooping is available. This is needed for some drivers so
+ * that they can select the most efficient copy routines.  
+ *
+ */
+
+static inline int set_snooping(void) 
+{
+        int tmp;        
+        asm(" lda [%1] 2, %0 "
+            : "=r"(tmp)
+            : "r"(0xC)
+        );
+        return (tmp >> 27) & 1;
+}
+
+/*
  *  bsp_pretasking_hook
  *
  *  BSP pretasking hook.  Called just before drivers are initialized.
@@ -112,4 +137,6 @@ void bsp_start( void )
   }
 
   BSP_Configuration.work_space_start = work_space_start;
+  
+  CPU_SPARC_HAS_SNOOPING = set_snooping();
 }