Changeset 4cb04f2 in rtems for c/src/lib/libbsp/sparc/leon3/startup/bspstart.c

Timestamp:

09/06/07 00:03:16 (15 years ago)

Author:

Joel Sherrill <joel.sherrill@…>

Branches:

4.10, 4.11, 4.8, 4.9, 5, master

Children:

3d0d969

Parents:

5982921

Message:

2007-09-05 Daniel Hellstrom <daniel@…>

• 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...)

File:

• c/src/lib/libbsp/sparc/leon3/startup/bspstart.c (modified) (2 diffs)

c/src/lib/libbsp/sparc/leon3/startup/bspstart.c

@@ -43 +43 @@
 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;
+}
 
 /*
@@ -113 +138 @@
 
   BSP_Configuration.work_space_start = work_space_start;
+  
+  CPU_SPARC_HAS_SNOOPING = set_snooping();
 }