Try insructioin-only cache.

4 files changed, 38 insertions, 11 deletions

diff --git a/c/src/lib/libbsp/m68k/uC5282/ChangeLog b/c/src/lib/libbsp/m68k/uC5282/ChangeLog
index bdd6293d53..24185ffa27 100644
--- a/c/src/lib/libbsp/m68k/uC5282/ChangeLog
+++ b/c/src/lib/libbsp/m68k/uC5282/ChangeLog
@@ -1,3 +1,8 @@
+2005-04-20  Eric Norum <norume@aps.anl.gov>
+
+	* startup/bspstart.c
+	* network/network.c: Try instruction-only cache.
+
 2005-04-19  Eric Norum <norume@aps.anl.gov>
 
 	* startup/bspstart.c: Expose read/write copy of cache control registers
diff --git a/c/src/lib/libbsp/m68k/uC5282/include/bsp.h b/c/src/lib/libbsp/m68k/uC5282/include/bsp.h
index 9297aad756..7cff0ba590 100644
--- a/c/src/lib/libbsp/m68k/uC5282/include/bsp.h
+++ b/c/src/lib/libbsp/m68k/uC5282/include/bsp.h
@@ -17,6 +17,14 @@ extern "C" {
 #include <rtems/bspIo.h>
 
 /***************************************************************************/
+/**  BSP Configuration                                                    **/
+/*
+ * Uncomment to use instruction/data cache
+ * Leave commented to use instruction-only cache
+ */
+/* #define RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE */
+
+/***************************************************************************/
 /**  Hardware data structure headers                                      **/
 #include <mcf5282/mcf5282.h>   /* internal MCF5282 modules */
 
diff --git a/c/src/lib/libbsp/m68k/uC5282/network/network.c b/c/src/lib/libbsp/m68k/uC5282/network/network.c
index 85e1a4f81a..a2e700d302 100644
--- a/c/src/lib/libbsp/m68k/uC5282/network/network.c
+++ b/c/src/lib/libbsp/m68k/uC5282/network/network.c
@@ -407,16 +407,18 @@ fec_rxDaemon (void *arg)
             struct ether_header *eh;
             int len = rxBd->length - sizeof(uint32_t);;
 
+            m = sc->rxMbuf[rxBdIndex];
+#ifdef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE
             /*
-             * Invalidate the cache and push the packet up.
-             * The cache is so small that it's more efficient to just
-             * invalidate the whole thing unless the packet is very small.
+             * Invalidate the cache.  The cache is so small that it's
+             * more efficient to just invalidate the whole thing unless
+             * the packet is very small.
              */
-            m = sc->rxMbuf[rxBdIndex];
             if (len < 128)
                 rtems_cache_invalidate_multiple_data_lines(m->m_data, len);
             else
                 rtems_cache_invalidate_entire_data();
+#endif
             m->m_len = m->m_pkthdr.len = len - sizeof(struct ether_header);
             eh = mtod(m, struct ether_header *);
             m->m_data += sizeof(struct ether_header);
diff --git a/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c b/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c
index aa900030fd..b3c11c7cf5 100644
--- a/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c
+++ b/c/src/lib/libbsp/m68k/uC5282/startup/bspstart.c
@@ -69,19 +69,23 @@ char *rtems_progname;
  * corruption problem.
  * DATECODES AFFECTED: All
  */
-#define m68k_set_cacr(_cacr) asm volatile ("movec %0,%%cacr ; nop" : : "d" (_cacr))
+#define m68k_set_cacr_nop(_cacr) asm volatile ("movec %0,%%cacr\n\tnop" : : "d" (_cacr))
+#define m68k_set_cacr(_cacr) asm volatile ("movec %0,%%cacr" : : "d" (_cacr))
 #define m68k_set_acr0(_acr0) asm volatile ("movec %0,%%acr0" : : "d" (_acr0))
 #define m68k_set_acr1(_acr1) asm volatile ("movec %0,%%acr1" : : "d" (_acr1))
 
 /*
  * Read/write copy of cache registers
- *   Split I/D cache
+ *   Split instruction/data or instruction-only
  *   Allow CPUSHL to invalidate a cache line
  *   Enable buffered writes
  *   No burst transfers on non-cacheable accesses
  *   Default cache mode is *disabled* (cache only ACRx areas)
  */
 uint32_t mcf5282_cacr_mode = MCF5XXX_CACR_CENB |
+#ifndef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE
+                             MCF5XXX_CACR_DISD |
+#endif
                              MCF5XXX_CACR_DBWE |
                              MCF5XXX_CACR_DCM;
 uint32_t mcf5282_acr0_mode = 0;
@@ -122,7 +126,7 @@ void _CPU_cache_disable_instruction(void)
 
 void _CPU_cache_invalidate_entire_instruction(void)
 {
-    m68k_set_cacr(mcf5282_cacr_mode | MCF5XXX_CACR_CINV | MCF5XXX_CACR_INVI);
+    m68k_set_cacr_nop(mcf5282_cacr_mode | MCF5XXX_CACR_CINV | MCF5XXX_CACR_INVI);
 }
 
 void _CPU_cache_invalidate_1_instruction_line(const void *addr)
@@ -136,37 +140,45 @@ void _CPU_cache_invalidate_1_instruction_line(const void *addr)
 
 void _CPU_cache_enable_data(void)
 {
+#ifdef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE
     rtems_interrupt_level level;
 
     rtems_interrupt_disable(level);
-    mcf5282_cacr_mode &= ~MCF5XXX_CACR_DISD;
+    mcf5282_cacr_mode &= ~MCF5XXX_CACR_CENB;
     m68k_set_cacr(mcf5282_cacr_mode);
     rtems_interrupt_enable(level);
+#endif
 }
 
 void _CPU_cache_disable_data(void)
 {
+#ifdef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE
     rtems_interrupt_level level;
 
     rtems_interrupt_disable(level);
     rtems_interrupt_disable(level);
-    mcf5282_cacr_mode |= MCF5XXX_CACR_DISD;
+    mcf5282_cacr_mode |= MCF5XXX_CACR_CENB;
     m68k_set_cacr(mcf5282_cacr_mode);
     rtems_interrupt_enable(level);
+#endif
 }
 
 void _CPU_cache_invalidate_entire_data(void)
 {
-    m68k_set_cacr(mcf5282_cacr_mode | MCF5XXX_CACR_CINV | MCF5XXX_CACR_INVD);
+#ifdef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE
+    m68k_set_cacr_nop(mcf5282_cacr_mode | MCF5XXX_CACR_CINV | MCF5XXX_CACR_INVD);
+#endif
 }
 
 void _CPU_cache_invalidate_1_data_line(const void *addr)
 {
+#ifdef RTEMS_MCF5282_BSP_ENABLE_DATA_CACHE
     /*
      * Bottom half of cache is D-space
      */
     addr = (void *)((int)addr & ~0x400);
     asm volatile ("cpushl %%bc,(%0)" :: "a" (addr));
+#endif
 }
 
 /*
@@ -220,7 +232,7 @@ void bsp_start( void )
      */
     m68k_set_acr0(mcf5282_acr0_mode);
     m68k_set_acr1(mcf5282_acr1_mode);
-    m68k_set_cacr(MCF5XXX_CACR_CINV);
+    m68k_set_cacr_nop(MCF5XXX_CACR_CINV);
 
     /*
      * Cache SDRAM