ppc4xx: Optimize PLB4 Arbiter and Memory Queue settings for PPC440SP/SPe,
	PPC405EX and PPC460EX/GT/SX

- Read pipeline depth set to 4 for PPC440SP/SPE, PPC405EX, PPC460EX/GT/SX
  processors
- Moved PLB4 Arbiter register definitions to ppc4xx.h since it is shared
  across processors (405 and 440/460)
- Optimize Memory Queue settings for PPC440SP/SPE and PPC460EX/GT/SX
  processors
- Add register bit definitions for Memory Queue Configuration registers

Signed-off-by: Prodyut Hazarika <phazarika@amcc.com>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/cpu/ppc4xx/44x_spd_ddr2.c b/cpu/ppc4xx/44x_spd_ddr2.c
index 1c36324..c7ed161 100644
--- a/cpu/ppc4xx/44x_spd_ddr2.c
+++ b/cpu/ppc4xx/44x_spd_ddr2.c
@@ -2172,6 +2172,11 @@
 	unsigned long i;
 	unsigned long bank_0_populated = 0;
 	phys_size_t total_size = 0;
+#if defined(CONFIG_440SP) || defined(CONFIG_440SPE) || \
+    defined(CONFIG_460EX) || defined(CONFIG_460GT) || \
+    defined(CONFIG_460SX)
+	unsigned long val;
+#endif
 
 	/*------------------------------------------------------------------
 	 * Reset the rank_base_address.
@@ -2249,17 +2254,31 @@
 		}
 	}
 
-#if defined(CONFIG_460EX) || defined(CONFIG_460GT)
+#if defined(CONFIG_440SP) || defined(CONFIG_440SPE) || \
+    defined(CONFIG_460EX) || defined(CONFIG_460GT) || \
+    defined(CONFIG_460SX)
+
 	/*
-	 * Enable high bandwidth access on 460EX/GT.
-	 * This should/could probably be done on other
-	 * PPC's too, like 440SPe.
+	 * Enable high bandwidth access
 	 * This is currently not used, but with this setup
 	 * it is possible to use it later on in e.g. the Linux
 	 * EMAC driver for performance gain.
 	 */
 	mtdcr(SDRAM_PLBADDULL, 0x00000000); /* MQ0_BAUL */
 	mtdcr(SDRAM_PLBADDUHB, 0x00000008); /* MQ0_BAUH */
+
+	/*
+	 * Set optimal value for Memory Queue HB/LL Configuration registers
+	 */
+
+	val = (mfdcr(SDRAM_CONF1HB) | SDRAM_CONF1HB_AAFR | SDRAM_CONF1HB_RPEN | SDRAM_CONF1HB_RFTE);
+	mtdcr(SDRAM_CONF1HB, val);
+
+	val = (mfdcr(SDRAM_CONF1LL) | SDRAM_CONF1LL_AAFR | SDRAM_CONF1LL_RPEN | SDRAM_CONF1LL_RFTE);
+	mtdcr(SDRAM_CONF1LL, val);
+
+	val = (mfdcr(SDRAM_CONFPATHB) | SDRAM_CONFPATHB_TPEN);
+	mtdcr(SDRAM_CONFPATHB, val);
 #endif
 }