patch-2.4.19 linux-2.4.19/arch/cris/mm/init.c

• Lines: 124
• Date: Fri Aug 2 17:39:42 2002
• Orig file: linux-2.4.18/arch/cris/mm/init.c
• Orig date: Mon Feb 25 11:37:52 2002

diff -urN linux-2.4.18/arch/cris/mm/init.c linux-2.4.19/arch/cris/mm/init.c
@@ -7,6 +7,18 @@
  *  Authors:  Bjorn Wesen (bjornw@axis.com)
  *
  *  $Log: init.c,v $
+ *  Revision 1.35  2002/05/17 05:33:59  starvik
+ *  Limit cache flush range to the size of the cache
+ *
+ *  Revision 1.34  2002/04/22 11:48:51  johana
+ *  Added KERN_INFO (2.4.19-pre7)
+ *
+ *  Revision 1.33  2002/03/19 15:22:17  bjornw
+ *  Added flush_etrax_cache
+ *
+ *  Revision 1.32  2002/03/15 17:09:31  bjornw
+ *  Added prepare_rx_descriptor as a workaround for a bug
+ *
  *  Revision 1.31  2001/11/13 16:22:00  bjornw
  *  Skip calculating totalram and sharedram in si_meminfo
  *
@@ -219,13 +231,15 @@
 #ifndef CONFIG_CRIS_LOW_MAP
 	/* This code is for the corrected Etrax-100 LX version 2... */
 
+#define CACHED_BOOTROM (KSEG_A | 0x08000000UL)
+
 	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg  ) | /* cached flash */
 			IO_STATE(R_MMU_KSEG, seg_e, seg  ) | /* uncached flash */
 			IO_STATE(R_MMU_KSEG, seg_d, page ) | /* vmalloc area */
 			IO_STATE(R_MMU_KSEG, seg_c, seg  ) | /* kernel area */
 			IO_STATE(R_MMU_KSEG, seg_b, seg  ) | /* kernel reg area */
-			IO_STATE(R_MMU_KSEG, seg_a, page ) | /* user area */
-			IO_STATE(R_MMU_KSEG, seg_9, page ) |
+			IO_STATE(R_MMU_KSEG, seg_a, seg  ) | /* bootrom/regs cached */ 
+			IO_STATE(R_MMU_KSEG, seg_9, page ) | /* user area */
 			IO_STATE(R_MMU_KSEG, seg_8, page ) |
 			IO_STATE(R_MMU_KSEG, seg_7, page ) |
 			IO_STATE(R_MMU_KSEG, seg_6, page ) |
@@ -241,7 +255,7 @@
 			    IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_c, 0x4 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_b, 0xb ) |
-			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0x0 ) |
+			    IO_FIELD(R_MMU_KBASE_HI, base_a, 0x3 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_9, 0x0 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_8, 0x0 ) );
 	
@@ -268,7 +282,9 @@
 	 * We map them straight over in LOW_MAP, but use vremap in LX version 2.
 	 */
 
-	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, page ) | 
+#define CACHED_BOOTROM (KSEG_F | 0x08000000UL)
+
+	*R_MMU_KSEG = ( IO_STATE(R_MMU_KSEG, seg_f, seg  ) |  /* cached bootrom/regs */ 
 			IO_STATE(R_MMU_KSEG, seg_e, page ) |
 			IO_STATE(R_MMU_KSEG, seg_d, page ) | 
 			IO_STATE(R_MMU_KSEG, seg_c, page ) |   
@@ -289,7 +305,7 @@
 			IO_STATE(R_MMU_KSEG, seg_1, page ) |  /* user area */
 			IO_STATE(R_MMU_KSEG, seg_0, page ) ); /* user area */
 
-	*R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x0 ) |
+	*R_MMU_KBASE_HI = ( IO_FIELD(R_MMU_KBASE_HI, base_f, 0x3 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_e, 0x0 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_d, 0x0 ) |
 			    IO_FIELD(R_MMU_KBASE_HI, base_c, 0x0 ) |
@@ -450,6 +466,48 @@
         }
 }
 
+/* Helper function for the two below */
+
+static inline void
+flush_etrax_cacherange(void *startadr, int length)
+{
+	/* CACHED_BOOTROM is mapped to the boot-rom area (cached) which
+	 * we can use to get fast dummy-reads of cachelines
+	 */
+
+	volatile short *flushadr = (volatile short *)(((unsigned long)startadr & ~PAGE_MASK) |
+						      CACHED_BOOTROM);
+
+	length = length > 8192 ? 8192 : length;  /* No need to flush more than cache size */
+
+	while(length > 0) {
+		short tmp = *flushadr;           /* dummy read to flush */
+		flushadr += (32/sizeof(short));  /* a cacheline is 32 bytes */
+		length -= 32;
+	}
+}
+
+/* Due to a bug in Etrax100(LX) all versions, receiving DMA buffers
+ * will occationally corrupt certain CPU writes if the DMA buffers
+ * happen to be hot in the cache.
+ * 
+ * As a workaround, we have to flush the relevant parts of the cache
+ * before (re) inserting any receiving descriptor into the DMA HW.
+ */
+
+void
+prepare_rx_descriptor(struct etrax_dma_descr *desc)
+{
+	flush_etrax_cacherange((void *)desc->buf, desc->sw_len ? desc->sw_len : 65536);
+}
+
+/* Do the same thing but flush the entire cache */
+
+void
+flush_etrax_cache(void)
+{
+	flush_etrax_cacherange(0, 8192);
+}
 
 /* free the pages occupied by initialization code */
 
@@ -465,7 +523,7 @@
                 free_page(addr);
                 totalram_pages++;
         }
-        printk ("Freeing unused kernel memory: %luk freed\n", 
+        printk (KERN_INFO "Freeing unused kernel memory: %luk freed\n", 
 		(&__init_end - &__init_begin) >> 10);
 }