1 files changed, 240 insertions, 0 deletions
diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
new file mode 100644
index 000000000..5f04a0141
--- /dev/null
+++ b/arch/mips/kernel/smp-mt.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2004, 05, 06 MIPS Technologies, Inc.
+ *    Elizabeth Clarke (beth@mips.com)
+ *    Ralf Baechle (ralf@linux-mips.org)
+ * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
+ */
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
+#include <linux/compiler.h>
+#include <linux/sched/task_stack.h>
+#include <linux/smp.h>
+
+#include <linux/atomic.h>
+#include <asm/cacheflush.h>
+#include <asm/cpu.h>
+#include <asm/processor.h>
+#include <asm/hardirq.h>
+#include <asm/mmu_context.h>
+#include <asm/time.h>
+#include <asm/mipsregs.h>
+#include <asm/mipsmtregs.h>
+#include <asm/mips_mt.h>
+#include <asm/mips-cps.h>
+
+static void __init smvp_copy_vpe_config(void)
+{
+	write_vpe_c0_status(
+		(read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
+
+	/* set config to be the same as vpe0, particularly kseg0 coherency alg */
+	write_vpe_c0_config( read_c0_config());
+
+	/* make sure there are no software interrupts pending */
+	write_vpe_c0_cause(0);
+
+	/* Propagate Config7 */
+	write_vpe_c0_config7(read_c0_config7());
+
+	write_vpe_c0_count(read_c0_count());
+}
+
+static unsigned int __init smvp_vpe_init(unsigned int tc, unsigned int mvpconf0,
+	unsigned int ncpu)
+{
+	if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))
+		return ncpu;
+
+	/* Deactivate all but VPE 0 */
+	if (tc != 0) {
+		unsigned long tmp = read_vpe_c0_vpeconf0();
+
+		tmp &= ~VPECONF0_VPA;
+
+		/* master VPE */
+		tmp |= VPECONF0_MVP;
+		write_vpe_c0_vpeconf0(tmp);
+
+		/* Record this as available CPU */
+		set_cpu_possible(tc, true);
+		set_cpu_present(tc, true);
+		__cpu_number_map[tc]	= ++ncpu;
+		__cpu_logical_map[ncpu] = tc;
+	}
+
+	/* Disable multi-threading with TC's */
+	write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
+
+	if (tc != 0)
+		smvp_copy_vpe_config();
+
+	cpu_set_vpe_id(&cpu_data[ncpu], tc);
+
+	return ncpu;
+}
+
+static void __init smvp_tc_init(unsigned int tc, unsigned int mvpconf0)
+{
+	unsigned long tmp;
+
+	if (!tc)
+		return;
+
+	/* bind a TC to each VPE, May as well put all excess TC's
+	   on the last VPE */
+	if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
+		write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
+	else {
+		write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
+
+		/* and set XTC */
+		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
+	}
+
+	tmp = read_tc_c0_tcstatus();
+
+	/* mark not allocated and not dynamically allocatable */
+	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
+	tmp |= TCSTATUS_IXMT;		/* interrupt exempt */
+	write_tc_c0_tcstatus(tmp);
+
+	write_tc_c0_tchalt(TCHALT_H);
+}
+
+static void vsmp_init_secondary(void)
+{
+	/* This is Malta specific: IPI,performance and timer interrupts */
+	if (mips_gic_present())
+		change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 |
+					 STATUSF_IP4 | STATUSF_IP5 |
+					 STATUSF_IP6 | STATUSF_IP7);
+	else
+		change_c0_status(ST0_IM, STATUSF_IP0 | STATUSF_IP1 |
+					 STATUSF_IP6 | STATUSF_IP7);
+}
+
+static void vsmp_smp_finish(void)
+{
+	/* CDFIXME: remove this? */
+	write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
+
+#ifdef CONFIG_MIPS_MT_FPAFF
+	/* If we have an FPU, enroll ourselves in the FPU-full mask */
+	if (cpu_has_fpu)
+		cpumask_set_cpu(smp_processor_id(), &mt_fpu_cpumask);
+#endif /* CONFIG_MIPS_MT_FPAFF */
+
+	local_irq_enable();
+}
+
+/*
+ * Setup the PC, SP, and GP of a secondary processor and start it
+ * running!
+ * smp_bootstrap is the place to resume from
+ * __KSTK_TOS(idle) is apparently the stack pointer
+ * (unsigned long)idle->thread_info the gp
+ * assumes a 1:1 mapping of TC => VPE
+ */
+static int vsmp_boot_secondary(int cpu, struct task_struct *idle)
+{
+	struct thread_info *gp = task_thread_info(idle);
+	dvpe();
+	set_c0_mvpcontrol(MVPCONTROL_VPC);
+
+	settc(cpu);
+
+	/* restart */
+	write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
+
+	/* enable the tc this vpe/cpu will be running */
+	write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
+
+	write_tc_c0_tchalt(0);
+
+	/* enable the VPE */
+	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
+
+	/* stack pointer */
+	write_tc_gpr_sp( __KSTK_TOS(idle));
+
+	/* global pointer */
+	write_tc_gpr_gp((unsigned long)gp);
+
+	flush_icache_range((unsigned long)gp,
+			   (unsigned long)(gp + sizeof(struct thread_info)));
+
+	/* finally out of configuration and into chaos */
+	clear_c0_mvpcontrol(MVPCONTROL_VPC);
+
+	evpe(EVPE_ENABLE);
+
+	return 0;
+}
+
+/*
+ * Common setup before any secondaries are started
+ * Make sure all CPU's are in a sensible state before we boot any of the
+ * secondaries
+ */
+static void __init vsmp_smp_setup(void)
+{
+	unsigned int mvpconf0, ntc, tc, ncpu = 0;
+	unsigned int nvpe;
+
+#ifdef CONFIG_MIPS_MT_FPAFF
+	/* If we have an FPU, enroll ourselves in the FPU-full mask */
+	if (cpu_has_fpu)
+		cpumask_set_cpu(0, &mt_fpu_cpumask);
+#endif /* CONFIG_MIPS_MT_FPAFF */
+	if (!cpu_has_mipsmt)
+		return;
+
+	/* disable MT so we can configure */
+	dvpe();
+	dmt();
+
+	/* Put MVPE's into 'configuration state' */
+	set_c0_mvpcontrol(MVPCONTROL_VPC);
+
+	mvpconf0 = read_c0_mvpconf0();
+	ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
+
+	nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
+	smp_num_siblings = nvpe;
+
+	/* we'll always have more TC's than VPE's, so loop setting everything
+	   to a sensible state */
+	for (tc = 0; tc <= ntc; tc++) {
+		settc(tc);
+
+		smvp_tc_init(tc, mvpconf0);
+		ncpu = smvp_vpe_init(tc, mvpconf0, ncpu);
+	}
+
+	/* Release config state */
+	clear_c0_mvpcontrol(MVPCONTROL_VPC);
+
+	/* We'll wait until starting the secondaries before starting MVPE */
+
+	printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
+}
+
+static void __init vsmp_prepare_cpus(unsigned int max_cpus)
+{
+	mips_mt_set_cpuoptions();
+}
+
+const struct plat_smp_ops vsmp_smp_ops = {
+	.send_ipi_single	= mips_smp_send_ipi_single,
+	.send_ipi_mask		= mips_smp_send_ipi_mask,
+	.init_secondary		= vsmp_init_secondary,
+	.smp_finish		= vsmp_smp_finish,
+	.boot_secondary		= vsmp_boot_secondary,
+	.smp_setup		= vsmp_smp_setup,
+	.prepare_cpus		= vsmp_prepare_cpus,
+};
+