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>

1 files changed, 44 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index ba093f553678..d7c1e69f3070 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -28,6 +28,7 @@
 #include <asm/dbell.h>
 #include <asm/fsl_guts.h>
 #include <asm/code-patching.h>
+#include <asm/cputhreads.h>
 
 #include <sysdev/fsl_soc.h>
 #include <sysdev/mpic.h>
@@ -168,6 +169,24 @@ static inline u32 read_spin_table_addr_l(void *spin_table)
 	return in_be32(&((struct epapr_spin_table *)spin_table)->addr_l);
 }
 
+#ifdef CONFIG_PPC64
+static void wake_hw_thread(void *info)
+{
+	void fsl_secondary_thread_init(void);
+	unsigned long imsr1, inia1;
+	int nr = *(const int *)info;
+
+	imsr1 = MSR_KERNEL;
+	inia1 = *(unsigned long *)fsl_secondary_thread_init;
+
+	mttmr(TMRN_IMSR1, imsr1);
+	mttmr(TMRN_INIA1, inia1);
+	mtspr(SPRN_TENS, TEN_THREAD(1));
+
+	smp_generic_kick_cpu(nr);
+}
+#endif
+
 static int smp_85xx_kick_cpu(int nr)
 {
 	unsigned long flags;
@@ -183,6 +202,31 @@ static int smp_85xx_kick_cpu(int nr)
 
 	pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
 
+#ifdef CONFIG_PPC64
+	/* Threads don't use the spin table */
+	if (cpu_thread_in_core(nr) != 0) {
+		int primary = cpu_first_thread_sibling(nr);
+
+		if (WARN_ON_ONCE(!cpu_has_feature(CPU_FTR_SMT)))
+			return -ENOENT;
+
+		if (cpu_thread_in_core(nr) != 1) {
+			pr_err("%s: cpu %d: invalid hw thread %d\n",
+			       __func__, nr, cpu_thread_in_core(nr));
+			return -ENOENT;
+		}
+
+		if (!cpu_online(primary)) {
+			pr_err("%s: cpu %d: primary %d not online\n",
+			       __func__, nr, primary);
+			return -ENOENT;
+		}
+
+		smp_call_function_single(primary, wake_hw_thread, &nr, 0);
+		return 0;
+	}
+#endif
+
 	np = of_get_cpu_node(nr, NULL);
 	cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);