powerpc/e6500: Add support for hardware threads

The general idea is that each core will release all of its
threads into the secondary thread startup code, which will
eventually wait in the secondary core holding area, for the
appropriate bit in the PACA to be set. The kick_cpu function
pointer will set that bit in the PACA, and thus "release"
the core/thread to boot. We also need to do a few things that
U-Boot normally does for CPUs (like enable branch prediction).

Signed-off-by: Andy Fleming <afleming@freescale.com>
[scottwood@freescale.com: various changes, including only enabling
 threads if Linux wants to kick them]
Signed-off-by: Scott Wood <scottwood@freescale.com>

4 files changed, 35 insertions, 9 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index a95145d7f61b..36ff6f03f903 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -180,6 +180,28 @@ exception_marker:
 #include "exceptions-64s.S"
 #endif
 
+#ifdef CONFIG_PPC_BOOK3E
+_GLOBAL(fsl_secondary_thread_init)
+	/* Enable branch prediction */
+	lis     r3,BUCSR_INIT@h
+	ori     r3,r3,BUCSR_INIT@l
+	mtspr   SPRN_BUCSR,r3
+	isync
+
+	/*
+	 * Fix PIR to match the linear numbering in the device tree.
+	 *
+	 * On e6500, the reset value of PIR uses the low three bits for
+	 * the thread within a core, and the upper bits for the core
+	 * number.  There are two threads per core, so shift everything
+	 * but the low bit right by two bits so that the cpu numbering is
+	 * continuous.
+	 */
+	mfspr	r3, SPRN_PIR
+	rlwimi	r3, r3, 30, 2, 30
+	mtspr	SPRN_PIR, r3
+#endif
+
 _GLOBAL(generic_secondary_thread_init)
 	mr	r24,r3
 
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 613a860a203c..0448b1e9c0ae 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -309,12 +309,10 @@ static int __init early_init_dt_scan_cpus(unsigned long node,
 
 	/* Get physical cpuid */
 	intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
-	if (intserv) {
-		nthreads = len / sizeof(int);
-	} else {
-		intserv = of_get_flat_dt_prop(node, "reg", NULL);
-		nthreads = 1;
-	}
+	if (!intserv)
+		intserv = of_get_flat_dt_prop(node, "reg", &len);
+
+	nthreads = len / sizeof(int);
 
 	/*
 	 * Now see if any of these threads match our boot cpu.
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index e239df3768ac..1bb4dcde0dcc 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -456,18 +456,20 @@ void __init smp_setup_cpu_maps(void)
 		intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
 				&len);
 		if (intserv) {
-			nthreads = len / sizeof(int);
 			DBG("    ibm,ppc-interrupt-server#s -> %d threads\n",
 			    nthreads);
 		} else {
 			DBG("    no ibm,ppc-interrupt-server#s -> 1 thread\n");
-			intserv = of_get_property(dn, "reg", NULL);
+			intserv = of_get_property(dn, "reg", &len);
 			if (!intserv) {
 				cpu_be = cpu_to_be32(cpu);
 				intserv = &cpu_be;	/* assume logical == phys */
+				len = 4;
 			}
 		}
 
+		nthreads = len / sizeof(int);
+
 		for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) {
 			DBG("    thread %d -> cpu %d (hard id %d)\n",
 			    j, cpu, be32_to_cpu(intserv[j]));
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index ee082d771178..6d06947e7d21 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -507,7 +507,11 @@ void __init setup_system(void)
 	check_smt_enabled();
 	setup_tlb_core_data();
 
-#ifdef CONFIG_SMP
+	/*
+	 * Freescale Book3e parts spin in a loop provided by firmware,
+	 * so smp_release_cpus() does nothing for them
+	 */
+#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_FSL_BOOK3E)
 	/* Release secondary cpus out of their spinloops at 0x60 now that
 	 * we can map physical -> logical CPU ids
 	 */