1 files changed, 172 insertions, 0 deletions
diff --git a/arch/mips/pmc-sierra/yosemite/smp.c b/arch/mips/pmc-sierra/yosemite/smp.c
new file mode 100644
index 000000000000..1d3b0734c78c
--- /dev/null
+++ b/arch/mips/pmc-sierra/yosemite/smp.c
@@ -0,0 +1,172 @@
+#include <linux/linkage.h>
+#include <linux/sched.h>
+
+#include <asm/pmon.h>
+#include <asm/titan_dep.h>
+
+extern unsigned int (*mips_hpt_read)(void);
+extern void (*mips_hpt_init)(unsigned int);
+
+#define LAUNCHSTACK_SIZE 256
+
+static spinlock_t launch_lock __initdata;
+
+static unsigned long secondary_sp __initdata;
+static unsigned long secondary_gp __initdata;
+
+static unsigned char launchstack[LAUNCHSTACK_SIZE] __initdata
+	__attribute__((aligned(2 * sizeof(long))));
+
+static void __init prom_smp_bootstrap(void)
+{
+	local_irq_disable();
+
+	while (spin_is_locked(&launch_lock));
+
+	__asm__ __volatile__(
+	"	move	$sp, %0		\n"
+	"	move	$gp, %1		\n"
+	"	j	smp_bootstrap	\n"
+	:
+	: "r" (secondary_sp), "r" (secondary_gp));
+}
+
+/*
+ * PMON is a fragile beast.  It'll blow up once the mappings it's littering
+ * right into the middle of KSEG3 are blown away so we have to grab the slave
+ * core early and keep it in a waiting loop.
+ */
+void __init prom_grab_secondary(void)
+{
+	spin_lock(&launch_lock);
+
+	pmon_cpustart(1, &prom_smp_bootstrap,
+	              launchstack + LAUNCHSTACK_SIZE, 0);
+}
+
+/*
+ * Detect available CPUs, populate phys_cpu_present_map before smp_init
+ *
+ * We don't want to start the secondary CPU yet nor do we have a nice probing
+ * feature in PMON so we just assume presence of the secondary core.
+ */
+static char maxcpus_string[] __initdata =
+	KERN_WARNING "max_cpus set to 0; using 1 instead\n";
+
+void __init prom_prepare_cpus(unsigned int max_cpus)
+{
+	int enabled = 0, i;
+
+	if (max_cpus == 0) {
+		printk(maxcpus_string);
+		max_cpus = 1;
+	}
+
+	cpus_clear(phys_cpu_present_map);
+
+	for (i = 0; i < 2; i++) {
+		if (i == max_cpus)
+			break;
+
+		/*
+		 * The boot CPU
+		 */
+		cpu_set(i, phys_cpu_present_map);
+		__cpu_number_map[i]	= i;
+		__cpu_logical_map[i]	= i;
+		enabled++;
+	}
+
+	/*
+	 * Be paranoid.  Enable the IPI only if we're really about to go SMP.
+	 */
+	if (enabled > 1)
+		set_c0_status(STATUSF_IP5);
+}
+
+/*
+ * Firmware CPU startup hook
+ * Complicated by PMON's weird interface which tries to minimic the UNIX fork.
+ * It launches the next * available CPU and copies some information on the
+ * stack so the first thing we do is throw away that stuff and load useful
+ * values into the registers ...
+ */
+void prom_boot_secondary(int cpu, struct task_struct *idle)
+{
+	unsigned long gp = (unsigned long) idle->thread_info;
+	unsigned long sp = gp + THREAD_SIZE - 32;
+
+	secondary_sp = sp;
+	secondary_gp = gp;
+
+	spin_unlock(&launch_lock);
+}
+
+/* Hook for after all CPUs are online */
+void prom_cpus_done(void)
+{
+}
+
+/*
+ *  After we've done initial boot, this function is called to allow the
+ *  board code to clean up state, if needed
+ */
+void prom_init_secondary(void)
+{
+	mips_hpt_init(mips_hpt_read());
+
+	set_c0_status(ST0_CO | ST0_IE | ST0_IM);
+}
+
+void prom_smp_finish(void)
+{
+}
+
+asmlinkage void titan_mailbox_irq(struct pt_regs *regs)
+{
+	int cpu = smp_processor_id();
+	unsigned long status;
+
+	if (cpu == 0) {
+		status = OCD_READ(RM9000x2_OCD_INTP0STATUS3);
+		OCD_WRITE(RM9000x2_OCD_INTP0CLEAR3, status);
+	}
+
+	if (cpu == 1) {
+		status = OCD_READ(RM9000x2_OCD_INTP1STATUS3);
+		OCD_WRITE(RM9000x2_OCD_INTP1CLEAR3, status);
+	}
+
+	if (status & 0x2)
+		smp_call_function_interrupt();
+}
+
+/*
+ * Send inter-processor interrupt
+ */
+void core_send_ipi(int cpu, unsigned int action)
+{
+	/*
+	 * Generate an INTMSG so that it can be sent over to the
+	 * destination CPU. The INTMSG will put the STATUS bits
+	 * based on the action desired. An alternative strategy
+	 * is to write to the Interrupt Set register, read the
+	 * Interrupt Status register and clear the Interrupt
+	 * Clear register. The latter is preffered.
+	 */
+	switch (action) {
+	case SMP_RESCHEDULE_YOURSELF:
+		if (cpu == 1)
+			OCD_WRITE(RM9000x2_OCD_INTP1SET3, 4);
+		else
+			OCD_WRITE(RM9000x2_OCD_INTP0SET3, 4);
+		break;
+
+	case SMP_CALL_FUNCTION:
+		if (cpu == 1)
+			OCD_WRITE(RM9000x2_OCD_INTP1SET3, 2);
+		else
+			OCD_WRITE(RM9000x2_OCD_INTP0SET3, 2);
+		break;
+	}
+}