powerpc/mp: add support for discontiguous cores

Some SOCs have discontiguously-numbered cores, and so we can't determine the
valid core numbers via the FRR register any more.  We define
CPU_TYPE_ENTRY_MASK to specify a discontiguous core mask, and helper functions
to process the mask and enumerate over the set of valid cores.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 34 insertions, 2 deletions

diff --git a/arch/powerpc/cpu/mpc8xxx/cpu.c b/arch/powerpc/cpu/mpc8xxx/cpu.c
index 767bc524d1..bb572cfff1 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;