Sequential accesses to non-existent memory must be synchronized,

at least on G2 cores.

This fixes get_ram_size() problems on MPC5200 Rev. B boards.

diff --git a/board/mcc200/mcc200.c b/board/mcc200/mcc200.c
index 71a691b..8b475c6 100644 (file)
--- a/board/mcc200/mcc200.c
+++ b/board/mcc200/mcc200.c
@@ -27,6 +27,7 @@
 #include <common.h>
 #include <mpc5xxx.h>
 #include <pci.h>
+#include <asm/processor.h>
 
 /* Two MT48LC8M32B2 for 32 MB */
 /* #include "mt48lc8m32b2-6-7.h" */
@@ -98,6 +99,7 @@ long int initdram (int board_type)
 {
        ulong dramsize = 0;
        ulong dramsize2 = 0;
+       uint svr, pvr;
 #ifndef CFG_RAMBOOT
        ulong test1, test2;
 
@@ -192,6 +194,23 @@ long int initdram (int board_type)
 
 #endif /* CFG_RAMBOOT */
 
+       /*
+        * On MPC5200B we need to set the special configuration delay in the
+        * DDR controller. Please refer to Freescale's AN3221 "MPC5200B SDRAM
+        * Initialization and Configuration", 3.3.1 SDelay--MBAR + 0x0190:
+        *
+        * "The SDelay should be written to a value of 0x00000004. It is
+        * required to account for changes caused by normal wafer processing
+        * parameters."
+        */
+       svr = get_svr();
+       pvr = get_pvr();
+       if ((SVR_MJREV(svr) >= 2) && (PVR_MAJ(pvr) == 1) && 
+           (PVR_MIN(pvr) == 4)) {
+               *(vu_long *)MPC5XXX_SDRAM_SDELAY = 0x04;
+               __asm__ volatile ("sync");
+       }
+
        return dramsize + dramsize2;
 }
 

diff --git a/common/memsize.c b/common/memsize.c
index dbc812d..6c275c9 100644 (file)
--- a/common/memsize.c
+++ b/common/memsize.c
@@ -21,6 +21,16 @@
  * MA 02111-1307 USA
  */
 
+#include <config.h>
+#ifdef __PPC__
+/*
+ * At least on G2 PowerPC cores, sequential accesses to non-existent
+ * memory must be synchronized.
+ */
+# include <asm/io.h>   /* for sync() */
+#else
+# define sync()                /* nothing */
+#endif
 
 /*
  * Check memory range for valid RAM. A simple memory test determines
@@ -38,20 +48,27 @@ long get_ram_size(volatile long *base, long maxsize)
 
        for (cnt = (maxsize / sizeof (long)) >> 1; cnt > 0; cnt >>= 1) {
                addr = base + cnt;      /* pointer arith! */
+               sync ();
                save[i++] = *addr;
+               sync ();
                *addr = ~cnt;
        }
 
        addr = base;
+       sync ();
        save[i] = *addr;
+       sync ();
        *addr = 0;
 
+       sync ();
        if ((val = *addr) != 0) {
                /* Restore the original data before leaving the function.
                 */
+               sync ();
                *addr = save[i];
                for (cnt = 1; cnt < maxsize / sizeof(long); cnt <<= 1) {
                        addr  = base + cnt;
+                       sync ();
                        *addr = save[--i];
                }
                return (0);

diff --git a/include/common.h b/include/common.h
index 349d5cf..ac78d1c 100644 (file)
--- a/include/common.h
+++ b/include/common.h
@@ -270,7 +270,7 @@ int misc_init_r   (void);
 void   jumptable_init(void);
 
 /* common/memsize.c */
-int    get_ram_size  (volatile long *, long);
+long   get_ram_size  (volatile long *, long);
 
 /* $(BOARD)/$(BOARD).c */
 void   reset_phy     (void);