ARM: l2c: realview: improve commentry about the L2 cache requirements

Add better commentry about the L2 cache requirements on these platforms. Unfortunately, the auxiliary control register is not pre-set to indicate the correct cache parameters, so we have to manually program these. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
git-mirror · May 29, 2014 · 39b5345 · 39b5345
1 parent 918197b
commit 39b5345
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Showing 3 changed files with 21 additions and 5 deletions.
diff --git a/arch/arm/mach-realview/realview_eb.c b/arch/arm/mach-realview/realview_eb.c
@@ -442,8 +442,13 @@ static void __init realview_eb_init(void)
 		realview_eb11mp_fixup();
 
 #ifdef CONFIG_CACHE_L2X0
-		/* 1MB (128KB/way), 8-way associativity, evmon/parity/share enabled
-		 * Bits:  .... ...0 0111 1001 0000 .... .... .... */
+		/*
+		 * The PL220 needs to be manually configured as the hardware
+		 * doesn't report the correct sizes.
+		 * 1MB (128KB/way), 8-way associativity, event monitor and
+		 * parity enabled, ignore share bit, no force write allocate
+		 * Bits:  .... ...0 0111 1001 0000 .... .... ....
+		 */
 		l2x0_init(__io_address(REALVIEW_EB11MP_L220_BASE), 0x00790000, 0xfe000fff);
 #endif
 		platform_device_register(&pmu_device);

diff --git a/arch/arm/mach-realview/realview_pb1176.c b/arch/arm/mach-realview/realview_pb1176.c
@@ -355,7 +355,13 @@ static void __init realview_pb1176_init(void)
 	int i;
 
 #ifdef CONFIG_CACHE_L2X0
-	/* 128Kb (16Kb/way) 8-way associativity. evmon/parity/share enabled. */
+	/*
+	 * The PL220 needs to be manually configured as the hardware
+	 * doesn't report the correct sizes.
+	 * 128kB (16kB/way), 8-way associativity, event monitor and
+	 * parity enabled, ignore share bit, no force write allocate
+	 * Bits:  .... ...0 0111 0011 0000 .... .... ....
+	 */
 	l2x0_init(__io_address(REALVIEW_PB1176_L220_BASE), 0x00730000, 0xfe000fff);
 #endif
 

diff --git a/arch/arm/mach-realview/realview_pb11mp.c b/arch/arm/mach-realview/realview_pb11mp.c
@@ -337,8 +337,13 @@ static void __init realview_pb11mp_init(void)
 	int i;
 
 #ifdef CONFIG_CACHE_L2X0
-	/* 1MB (128KB/way), 8-way associativity, evmon/parity/share enabled
-	 * Bits:  .... ...0 0111 1001 0000 .... .... .... */
+	/*
+	 * The PL220 needs to be manually configured as the hardware
+	 * doesn't report the correct sizes.
+	 * 1MB (128KB/way), 8-way associativity, event monitor and
+	 * parity enabled, ignore share bit, no force write allocate
+	 * Bits:  .... ...0 0111 1001 0000 .... .... ....
+	 */
 	l2x0_init(__io_address(REALVIEW_TC11MP_L220_BASE), 0x00790000, 0xfe000fff);
 #endif