powerpc/85xx: Handle the lack of L2 cache on P2040/P2040E

The P2040/P2040E have no L2 cache.  So we utilize the SVR to determine
if we are one of these devices and skip the L2 init code in cpu_init.c
and release.  For the device tree we skip the updating of the L2 cache
properties but we still update the chain of caches so the CPC/L3 node
can be properly updated.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/cpu/mpc85xx/cpu_init.c

@@ -392,6 +392,12 @@ int cpu_init_r(void)
 		puts("enabled\n");
 	}
 #elif defined(CONFIG_BACKSIDE_L2_CACHE)
+	if ((SVR_SOC_VER(get_svr()) == SVR_P2040) ||
+	    (SVR_SOC_VER(get_svr()) == SVR_P2040_E)) {
+		puts("N/A\n");
+		goto skip_l2;
+	}
+
 	u32 l2cfg0 = mfspr(SPRN_L2CFG0);
 
 	/* invalidate the L2 cache */
@@ -412,6 +418,8 @@ int cpu_init_r(void)
 			;
 		printf("%d KB enabled\n", (l2cfg0 & 0x3fff) * 64);
 	}
+
+skip_l2:
 #else
 	puts("disabled\n");
 #endif

arch/powerpc/cpu/mpc85xx/fdt.c

@@ -228,6 +228,12 @@ static inline void ft_fixup_l2cache(void *blob)
 	u32 *ph;
 	u32 l2cfg0 = mfspr(SPRN_L2CFG0);
 	u32 size, line_size, num_ways, num_sets;
+	int has_l2 = 1;
+
+	/* P2040/P2040E has no L2, so dont set any L2 props */
+	if ((SVR_SOC_VER(get_svr()) == SVR_P2040) ||
+	    (SVR_SOC_VER(get_svr()) == SVR_P2040_E))
+		has_l2 = 0;
 
 	size = (l2cfg0 & 0x3fff) * 64 * 1024;
 	num_ways = ((l2cfg0 >> 14) & 0x1f) + 1;
@@ -250,21 +256,22 @@ static inline void ft_fixup_l2cache(void *blob)
 			goto next;
 		}
 
+		if (has_l2) {
 #ifdef CONFIG_SYS_CACHE_STASHING
-		{
 			u32 *reg = (u32 *)fdt_getprop(blob, off, "reg", 0);
 			if (reg)
 				fdt_setprop_cell(blob, l2_off, "cache-stash-id",
 					 (*reg * 2) + 32 + 1);
-		}
 #endif
 
 			fdt_setprop(blob, l2_off, "cache-unified", NULL, 0);
-		fdt_setprop_cell(blob, l2_off, "cache-block-size", line_size);
+			fdt_setprop_cell(blob, l2_off, "cache-block-size",
+						line_size);
 			fdt_setprop_cell(blob, l2_off, "cache-size", size);
 			fdt_setprop_cell(blob, l2_off, "cache-sets", num_sets);
 			fdt_setprop_cell(blob, l2_off, "cache-level", 2);
 			fdt_setprop(blob, l2_off, "compatible", "cache", 6);
+		}
 
 		if (l3_off < 0) {
 			ph = (u32 *)fdt_getprop(blob, l2_off, "next-level-cache", 0);

arch/powerpc/cpu/mpc85xx/release.S

@@ -1,5 +1,5 @@
 /*
- * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008-2011 Freescale Semiconductor, Inc.
  * Kumar Gala <kumar.gala@freescale.com>
  *
  * See file CREDITS for list of people who contributed to this
@@ -144,6 +144,18 @@ __secondary_start_page:
 #endif
 
 #ifdef CONFIG_BACKSIDE_L2_CACHE
+	/* skip L2 setup on P2040/P2040E as they have no L2 */
+	mfspr	r2,SPRN_SVR
+	lis	r3,SVR_P2040@h
+	ori	r3,r3,SVR_P2040@l
+	cmpw	r2,r3
+	beq 3f
+
+	lis	r3,SVR_P2040_E@h
+	ori	r3,r3,SVR_P2040_E@l
+	cmpw	r2,r3
+	beq 3f
+
 	/* Enable/invalidate the L2 cache */
 	msync
 	lis	r2,(L2CSR0_L2FI|L2CSR0_L2LFC)@h
@@ -169,6 +181,7 @@ __secondary_start_page:
 	andis.	r1,r3,L2CSR0_L2E@h
 	beq	2b
 #endif
+3:
 
 #define EPAPR_MAGIC		(0x45504150)
 #define ENTRY_ADDR_UPPER	0