diff --git a/arch/powerpc/cpu/mpc85xx/cpu.c b/arch/powerpc/cpu/mpc85xx/cpu.c
index 22fa461..f51829e 100644
--- a/arch/powerpc/cpu/mpc85xx/cpu.c
+++ b/arch/powerpc/cpu/mpc85xx/cpu.c
@@ -64,7 +64,8 @@ int checkcpu (void)
 	u32 ddr_ratio = 0;
 #endif /* CONFIG_FSL_CORENET */
 #endif /* CONFIG_DDR_CLK_FREQ */
-	int i;
+	unsigned int i, core, nr_cores = cpu_numcores();
+	u32 mask = cpu_mask();
 
 	svr = get_svr();
 	major = SVR_MAJ(svr);
@@ -119,11 +120,11 @@ int checkcpu (void)
 	get_sys_info(&sysinfo);
 
 	puts("Clock Configuration:");
-	for (i = 0; i < cpu_numcores(); i++) {
+	for_each_cpu(i, core, nr_cores, mask) {
 		if (!(i & 3))
 			printf ("\n       ");
-		printf("CPU%d:%-4s MHz, ",
-				i,strmhz(buf1, sysinfo.freqProcessor[i]));
+		printf("CPU%d:%-4s MHz, ", core,
+			strmhz(buf1, sysinfo.freqProcessor[core]));
 	}
 	printf("\n       CCB:%-4s MHz,\n", strmhz(buf1, sysinfo.freqSystemBus));
 
diff --git a/arch/powerpc/cpu/mpc85xx/mp.c b/arch/powerpc/cpu/mpc85xx/mp.c
index 758e6d7..ffc2a9a 100644
--- a/arch/powerpc/cpu/mpc85xx/mp.c
+++ b/arch/powerpc/cpu/mpc85xx/mp.c
@@ -221,14 +221,14 @@ ulong get_spin_virt_addr(void)
 #ifdef CONFIG_FSL_CORENET
 static void plat_mp_up(unsigned long bootpg)
 {
-	u32 up, cpu_up_mask, whoami;
+	u32 cpu_up_mask, whoami;
 	u32 *table = (u32 *)get_spin_virt_addr();
 	volatile ccsr_gur_t *gur;
 	volatile ccsr_local_t *ccm;
 	volatile ccsr_rcpm_t *rcpm;
 	volatile ccsr_pic_t *pic;
 	int timeout = 10;
-	u32 nr_cpus;
+	u32 mask = cpu_mask();
 	struct law_entry e;
 
 	gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
@@ -236,8 +236,6 @@ static void plat_mp_up(unsigned long bootpg)
 	rcpm = (void *)(CONFIG_SYS_FSL_CORENET_RCPM_ADDR);
 	pic = (void *)(CONFIG_SYS_MPC8xxx_PIC_ADDR);
 
-	nr_cpus = ((in_be32(&pic->frr) >> 8) & 0xff) + 1;
-
 	whoami = in_be32(&pic->whoami);
 	cpu_up_mask = 1 << whoami;
 	out_be32(&ccm->bstrl, bootpg);
@@ -251,19 +249,18 @@ static void plat_mp_up(unsigned long bootpg)
 	/* disable time base at the platform */
 	out_be32(&rcpm->ctbenrl, cpu_up_mask);
 
-	/* release the hounds */
-	up = ((1 << nr_cpus) - 1);
-	out_be32(&gur->brrl, up);
+	out_be32(&gur->brrl, mask);
 
 	/* wait for everyone */
 	while (timeout) {
-		int i;
-		for (i = 0; i < nr_cpus; i++) {
-			if (table[i * NUM_BOOT_ENTRY + BOOT_ENTRY_ADDR_LOWER])
-				cpu_up_mask |= (1 << i);
-		};
+		unsigned int i, cpu, nr_cpus = cpu_numcores();
 
-		if ((cpu_up_mask & up) == up)
+		for_each_cpu(i, cpu, nr_cpus, mask) {
+			if (table[cpu * NUM_BOOT_ENTRY + BOOT_ENTRY_ADDR_LOWER])
+				cpu_up_mask |= (1 << cpu);
+		}
+
+		if ((cpu_up_mask & mask) == mask)
 			break;
 
 		udelay(100);
@@ -272,7 +269,7 @@ static void plat_mp_up(unsigned long bootpg)
 
 	if (timeout == 0)
 		printf("CPU up timeout. CPU up mask is %x should be %x\n",
-			cpu_up_mask, up);
+			cpu_up_mask, mask);
 
 	/* enable time base at the platform */
 	out_be32(&rcpm->ctbenrl, 0);
@@ -283,7 +280,7 @@ static void plat_mp_up(unsigned long bootpg)
 	mtspr(SPRN_TBWU, 0);
 	mtspr(SPRN_TBWL, 0);
 
-	out_be32(&rcpm->ctbenrl, (1 << nr_cpus) - 1);
+	out_be32(&rcpm->ctbenrl, mask);
 
 #ifdef CONFIG_MPC8xxx_DISABLE_BPTR
 	/*
diff --git a/arch/powerpc/cpu/mpc85xx/speed.c b/arch/powerpc/cpu/mpc85xx/speed.c
index a83dfeb..ce47532 100644
--- a/arch/powerpc/cpu/mpc85xx/speed.c
+++ b/arch/powerpc/cpu/mpc85xx/speed.c
@@ -41,6 +41,7 @@ void get_sys_info (sys_info_t * sysInfo)
 	volatile ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
 #ifdef CONFIG_FSL_CORENET
 	volatile ccsr_clk_t *clk = (void *)(CONFIG_SYS_FSL_CORENET_CLK_ADDR);
+	unsigned int cpu;
 
 	const u8 core_cplx_PLL[16] = {
 		[ 0] = 0,	/* CC1 PPL / 1 */
@@ -97,11 +98,11 @@ void get_sys_info (sys_info_t * sysInfo)
 			freqCC_PLL[i] = sysInfo->freqSystemBus * ratio[i];
 	}
 	rcw_tmp = in_be32(&gur->rcwsr[3]);
-	for (i = 0; i < cpu_numcores(); i++) {
-		u32 c_pll_sel = (in_be32(&clk->clkc0csr + i*8) >> 27) & 0xf;
+	for_each_cpu(i, cpu, cpu_numcores(), cpu_mask()) {
+		u32 c_pll_sel = (in_be32(&clk->clkc0csr + cpu*8) >> 27) & 0xf;
 		u32 cplx_pll = core_cplx_PLL[c_pll_sel];
 
-		sysInfo->freqProcessor[i] =
+		sysInfo->freqProcessor[cpu] =
 			 freqCC_PLL[cplx_pll] / core_cplx_PLL_div[c_pll_sel];
 	}
 
diff --git a/arch/powerpc/cpu/mpc8xxx/cpu.c b/arch/powerpc/cpu/mpc8xxx/cpu.c
index 767bc52..bb572cf 100644
--- a/arch/powerpc/cpu/mpc8xxx/cpu.c
+++ b/arch/powerpc/cpu/mpc8xxx/cpu.c
@@ -129,13 +129,33 @@ struct cpu_type *identify_cpu(u32 ver)
 	return &cpu_type_unknown;
 }
 
+#define MPC8xxx_PICFRR_NCPU_MASK  0x00001f00
+#define MPC8xxx_PICFRR_NCPU_SHIFT 8
+
+/*
+ * Return a 32-bit mask indicating which cores are present on this SOC.
+ */
+u32 cpu_mask()
+{
+	ccsr_pic_t __iomem *pic = (void *)CONFIG_SYS_MPC8xxx_PIC_ADDR;
+	struct cpu_type *cpu = gd->cpu;
+
+	/* better to query feature reporting register than just assume 1 */
+	if (cpu == &cpu_type_unknown)
+	return ((in_be32(&pic->frr) & MPC8xxx_PICFRR_NCPU_MASK) >>
+			MPC8xxx_PICFRR_NCPU_SHIFT) + 1;
+
+	return cpu->mask;
+}
+
+/*
+ * Return the number of cores on this SOC.
+ */
 int cpu_numcores() {
 	ccsr_pic_t __iomem *pic = (void *)CONFIG_SYS_MPC8xxx_PIC_ADDR;
 	struct cpu_type *cpu = gd->cpu;
 
 	/* better to query feature reporting register than just assume 1 */
-#define MPC8xxx_PICFRR_NCPU_MASK 0x00001f00
-#define MPC8xxx_PICFRR_NCPU_SHIFT 8
 	if (cpu == &cpu_type_unknown)
 		return ((in_be32(&pic->frr) & MPC8xxx_PICFRR_NCPU_MASK) >>
 			MPC8xxx_PICFRR_NCPU_SHIFT) + 1;
@@ -143,6 +163,18 @@ int cpu_numcores() {
 	return cpu->num_cores;
 }
 
+/*
+ * Check if the given core ID is valid
+ *
+ * Returns zero if it isn't, 1 if it is.
+ */
+int is_core_valid(unsigned int core)
+{
+	struct cpu_type *cpu = gd->cpu;
+
+	return !!((1 << core) & cpu->mask);
+}
+
 int probecpu (void)
 {
 	uint svr;
diff --git a/arch/powerpc/cpu/mpc8xxx/fdt.c b/arch/powerpc/cpu/mpc8xxx/fdt.c
index 285051d..5bb9f53 100644
--- a/arch/powerpc/cpu/mpc8xxx/fdt.c
+++ b/arch/powerpc/cpu/mpc8xxx/fdt.c
@@ -63,7 +63,7 @@ void ft_fixup_num_cores(void *blob) {
 	while (off != -FDT_ERR_NOTFOUND) {
 		u32 *reg = (u32 *)fdt_getprop(blob, off, "reg", 0);
 
-		if ((*reg > num_cores-1) || (is_core_disabled(*reg))) {
+		if (!is_core_valid(*reg) || is_core_disabled(*reg)) {
 			int ph = fdt_get_phandle(blob, off);
 
 			/* Delete the cpu node once there are no cpu handles */
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 0c4cc25..50af6e7 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -1176,13 +1176,17 @@ struct cpu_type {
 	char name[15];
 	u32 soc_ver;
 	u32 num_cores;
+	u32 mask;	/* which cpu(s) actually exist */
 };
 
 struct cpu_type *identify_cpu(u32 ver);
 
 #if defined(CONFIG_MPC85xx) || defined(CONFIG_MPC86xx)
 #define CPU_TYPE_ENTRY(n, v, nc) \
-	{ .name = #n, .soc_ver = SVR_##v, .num_cores = (nc), }
+	{ .name = #n, .soc_ver = SVR_##v, .num_cores = (nc), \
+	  .mask = (1 << (nc)) - 1 }
+#define CPU_TYPE_ENTRY_MASK(n, v, nc, m) \
+	{ .name = #n, .soc_ver = SVR_##v, .num_cores = (nc), .mask = (m) }
 #else
 #if defined(CONFIG_MPC83xx)
 #define CPU_TYPE_ENTRY(x) {#x, SPR_##x}
diff --git a/common/cmd_mp.c b/common/cmd_mp.c
index f19bf41..b115b59 100644
--- a/common/cmd_mp.c
+++ b/common/cmd_mp.c
@@ -32,9 +32,8 @@ cpu_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 		return cmd_usage(cmdtp);
 
 	cpuid = simple_strtoul(argv[1], NULL, 10);
-	if (cpuid >= cpu_numcores()) {
-		printf ("Core num: %lu is out of range[0..%d]\n",
-				cpuid, cpu_numcores() - 1);
+	if (!is_core_valid(cpuid)) {
+		printf ("Core num: %lu is not valid\n",	cpuid);
 		return 1;
 	}
 
diff --git a/include/common.h b/include/common.h
index 1572791..f975023 100644
--- a/include/common.h
+++ b/include/common.h
@@ -461,7 +461,22 @@ void ddr_enable_ecc(unsigned int dram_size);
 #endif
 
 /* $(CPU)/cpu.c */
+static inline int cpumask_next(int cpu, unsigned int mask)
+{
+	for (cpu++; !((1 << cpu) & mask); cpu++)
+		;
+
+	return cpu;
+}
+
+#define for_each_cpu(iter, cpu, num_cpus, mask) \
+	for (iter = 0, cpu = cpumask_next(-1, mask); \
+		iter < num_cpus; \
+		iter++, cpu = cpumask_next(cpu, mask)) \
+
 int	cpu_numcores  (void);
+u32	cpu_mask      (void);
+int	is_core_valid (unsigned int);
 int	probecpu      (void);
 int	checkcpu      (void);
 int	checkicache   (void);
