@@ -8,10 +8,14 @@
#include <asm/bootinfo.h>
#include <asm/fw/fw.h>
+#include <asm/mach-jz4740/smp.h>
void __init prom_init(void)
{
fw_init_cmdline();
+
+ if (IS_ENABLED(CONFIG_SMP))
+ jz4780_smp_init();
}
void __init prom_free_prom_memory(void)
diff --git a/arch/mips/jz4740/smp-entry.S b/arch/mips/jz4740/smp-entry.S
new file mode 100644
index 00000000..20049a3
--- /dev/null
+++ b/arch/mips/jz4740/smp-entry.S
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2013, Paul Burton <paul.burton@xxxxxxxxxx>
+ * JZ4780 SMP entry point
+ */
+
+#include <asm/addrspace.h>
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/cacheops.h>
+#include <asm/mipsregs.h>
+
+#define CACHE_SIZE (32 * 1024)
+#define CACHE_LINESIZE 32
+
+.extern jz4780_cpu_entry_sp
+.extern jz4780_cpu_entry_gp
+
+.section .text.smp-entry
+.balign 0x10000
+.set noreorder
+LEAF(jz4780_secondary_cpu_entry)
+ mtc0 zero, CP0_CAUSE
+
+ li t0, ST0_CU0
+ mtc0 t0, CP0_STATUS
+
+ /* cache setup */
+ li t0, KSEG0
+ ori t1, t0, CACHE_SIZE
+ mtc0 zero, CP0_TAGLO, 0
+1: cache Index_Store_Tag_I, 0(t0)
+ cache Index_Store_Tag_D, 0(t0)
+ bne t0, t1, 1b
+ addiu t0, t0, CACHE_LINESIZE
+
+ /* kseg0 cache attribute */
+ mfc0 t0, CP0_CONFIG, 0
+ ori t0, t0, CONF_CM_CACHABLE_NONCOHERENT
+ mtc0 t0, CP0_CONFIG, 0
+
+ /* pagemask */
+ mtc0 zero, CP0_PAGEMASK, 0
+
+ /* retrieve sp */
+ la t0, jz4780_cpu_entry_sp
+ lw sp, 0(t0)
+
+ /* retrieve gp */
+ la t0, jz4780_cpu_entry_gp
+ lw gp, 0(t0)
+
+ /* jump to the kernel in kseg0 */
+ la t0, smp_bootstrap
+ jr t0
+ nop
+ END(jz4780_secondary_cpu_entry)
diff --git a/arch/mips/jz4740/smp.c b/arch/mips/jz4740/smp.c
new file mode 100644
index 00000000..d95d22a
--- /dev/null
+++ b/arch/mips/jz4740/smp.c
@@ -0,0 +1,258 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2013, Paul Burton <paul.burton@xxxxxxxxxx>
+ * JZ4780 SMP
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/sched.h>
+#include <linux/sched/task_stack.h>
+#include <linux/smp.h>
+#include <linux/tick.h>
+#include <asm/mach-jz4740/smp.h>
+#include <asm/smp-ops.h>
+
+static struct clk *cpu_clock_gates[CONFIG_NR_CPUS] = { NULL };
+
+u32 jz4780_cpu_entry_sp;
+u32 jz4780_cpu_entry_gp;
+
+static struct cpumask cpu_running;
+
+static DEFINE_SPINLOCK(smp_lock);
+
+static irqreturn_t mbox_handler(int irq, void *dev_id)
+{
+ int cpu = smp_processor_id();
+ u32 action, status;
+
+ spin_lock(&smp_lock);
+
+ switch (cpu) {
+ case 0:
+ action = read_c0_mailbox0();
+ write_c0_mailbox0(0);
+ break;
+ case 1:
+ action = read_c0_mailbox1();
+ write_c0_mailbox1(0);
+ break;
+ case 2:
+ action = read_c0_mailbox2();
+ write_c0_mailbox2(0);
+ break;
+ case 3:
+ action = read_c0_mailbox3();
+ write_c0_mailbox3(0);
+ break;
+ default:
+ panic("unhandled cpu %d!", cpu);
+ }
+
+ /* clear pending mailbox interrupt */
+ status = read_c0_corestatus();
+ status &= ~(CORESTATUS_MIRQ0P << cpu);
+ write_c0_corestatus(status);
+
+ spin_unlock(&smp_lock);
+
+ if (action & SMP_RESCHEDULE_YOURSELF)
+ scheduler_ipi();
+ if (action & SMP_CALL_FUNCTION)
+ generic_smp_call_function_interrupt();
+
+ return IRQ_HANDLED;
+}
+
+static void jz4780_smp_setup(void)
+{
+ u32 addr, reim;
+ int cpu;
+
+ reim = read_c0_reim();
+
+ for (cpu = 0; cpu < NR_CPUS; cpu++) {
+ __cpu_number_map[cpu] = cpu;
+ __cpu_logical_map[cpu] = cpu;
+ set_cpu_possible(cpu, true);
+ }
+
+ /* mask mailbox interrupts for this core */
+ reim &= ~REIM_MBOXIRQ0M;
+ write_c0_reim(reim);
+
+ /* clear mailboxes & pending mailbox IRQs */
+ write_c0_mailbox0(0);
+ write_c0_mailbox1(0);
+ write_c0_corestatus(0);
+
+ /* set reset entry point */
+ addr = KSEG1ADDR((u32)&jz4780_secondary_cpu_entry);
+ WARN_ON(addr & ~REIM_ENTRY);
+ reim &= ~REIM_ENTRY;
+ reim |= addr & REIM_ENTRY;
+
+ /* unmask mailbox interrupts for this core */
+ reim |= REIM_MBOXIRQ0M;
+ write_c0_reim(reim);
+ set_c0_status(STATUSF_IP3);
+ irq_enable_hazard();
+
+ cpumask_set_cpu(cpu, &cpu_running);
+}
+
+static void jz4780_smp_prepare_cpus(unsigned int max_cpus)
+{
+ struct device_node *cpu_node;
+ unsigned cpu, ctrl;
+ int err;
+
+ /* setup the mailbox IRQ */
+ err = request_irq(MIPS_CPU_IRQ_BASE + 3, mbox_handler,
+ IRQF_PERCPU | IRQF_NO_THREAD, "core mailbox", NULL);
+ if (err)
+ pr_err("request_irq() on core mailbox failed\n");
+
+ ctrl = read_c0_corectrl();
+
+ for_each_of_cpu_node(cpu_node) {
+ cpu = of_cpu_node_to_id(cpu_node);
+ if (cpu < 0) {
+ pr_err("Failed to read index of %s\n",
+ cpu_node->full_name);
+ continue;
+ }
+
+ /* use reset entry point from REIM register */
+ ctrl |= CORECTRL_RPC0 << cpu;
+
+ cpu_clock_gates[cpu] = of_clk_get(cpu_node, 0);
+ if (IS_ERR(cpu_clock_gates[cpu])) {
+ cpu_clock_gates[cpu] = NULL;
+ continue;
+ }
+
+ err = clk_prepare(cpu_clock_gates[cpu]);
+ if (err)
+ pr_err("Failed to prepare CPU clock gate\n");
+ }
+
+ write_c0_corectrl(ctrl);
+}
+
+static int jz4780_boot_secondary(int cpu, struct task_struct *idle)
+{
+ unsigned long flags;
+ u32 ctrl;
+
+ spin_lock_irqsave(&smp_lock, flags);
+
+ /* ensure the core is in reset */
+ ctrl = read_c0_corectrl();
+ ctrl |= CORECTRL_SWRST0 << cpu;
+ write_c0_corectrl(ctrl);
+
+ /* ungate core clock */
+ if (cpu_clock_gates[cpu])
+ clk_enable(cpu_clock_gates[cpu]);
+
+ /* set entry sp/gp register values */
+ jz4780_cpu_entry_sp = __KSTK_TOS(idle);
+ jz4780_cpu_entry_gp = (u32)task_thread_info(idle);
+ smp_wmb();
+
+ /* take the core out of reset */
+ ctrl &= ~(CORECTRL_SWRST0 << cpu);
+ write_c0_corectrl(ctrl);
+
+ cpumask_set_cpu(cpu, &cpu_running);
+
+ spin_unlock_irqrestore(&smp_lock, flags);
+
+ return 0;
+}
+
+static void jz4780_init_secondary(void)
+{
+}
+
+static void jz4780_smp_finish(void)
+{
+ u32 reim;
+
+ spin_lock(&smp_lock);
+
+ /* unmask mailbox interrupts for this core */
+ reim = read_c0_reim();
+ reim |= REIM_MBOXIRQ0M << smp_processor_id();
+ write_c0_reim(reim);
+
+ spin_unlock(&smp_lock);
+
+ /* unmask interrupts for this core */
+ change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP2 |
+ STATUSF_IP1 | STATUSF_IP0);
+ irq_enable_hazard();
+
+ /* force broadcast timer */
+ tick_broadcast_force();
+}
+
+static void jz4780_send_ipi_single_locked(int cpu, unsigned int action)
+{
+ u32 mbox;
+
+ switch (cpu) {
+ case 0:
+ mbox = read_c0_mailbox0();
+ write_c0_mailbox0(mbox | action);
+ break;
+ case 1:
+ mbox = read_c0_mailbox1();
+ write_c0_mailbox1(mbox | action);
+ break;
+ default:
+ panic("unhandled cpu %d!", cpu);
+ }
+}
+
+static void jz4780_send_ipi_single(int cpu, unsigned int action)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&smp_lock, flags);
+ jz4780_send_ipi_single_locked(cpu, action);
+ spin_unlock_irqrestore(&smp_lock, flags);
+}
+
+static void jz4780_send_ipi_mask(const struct cpumask *mask,
+ unsigned int action)
+{
+ unsigned long flags;
+ int cpu;
+
+ spin_lock_irqsave(&smp_lock, flags);
+
+ for_each_cpu(cpu, mask)
+ jz4780_send_ipi_single_locked(cpu, action);
+
+ spin_unlock_irqrestore(&smp_lock, flags);
+}
+
+static struct plat_smp_ops jz4780_smp_ops = {
+ .send_ipi_single = jz4780_send_ipi_single,
+ .send_ipi_mask = jz4780_send_ipi_mask,
+ .init_secondary = jz4780_init_secondary,
+ .smp_finish = jz4780_smp_finish,
+ .boot_secondary = jz4780_boot_secondary,
+ .smp_setup = jz4780_smp_setup,
+ .prepare_cpus = jz4780_smp_prepare_cpus,
+};
+
+void __init jz4780_smp_init(void)
+{
+ register_smp_ops(&jz4780_smp_ops);
+}
diff --git a/arch/mips/kernel/idle.c b/arch/mips/kernel/idle.c
index 37f8e78..d33f2d4 100644
--- a/arch/mips/kernel/idle.c
+++ b/arch/mips/kernel/idle.c
@@ -18,6 +18,7 @@
#include <asm/cpu-type.h>
#include <asm/idle.h>
#include <asm/mipsregs.h>
+#include <asm/r4kcache.h>
/*
* Not all of the MIPS CPUs have the "wait" instruction available.
Moreover,
@@ -88,6 +89,34 @@ static void __cpuidle rm7k_wait_irqoff(void)
}
/*
+ * The Ingenic jz4780 SMP variant has to write back dirty cache
lines before
+ * executing wait. The CPU & cache clock will be gated until we
return from
+ * the wait, and if another core attempts to access data from our
data cache
+ * during this time then it will lock up.
+ */
+void jz4780_smp_wait_irqoff(void)
+{
+ unsigned long pending = read_c0_cause() & read_c0_status() &
CAUSEF_IP;
+
+ /*
+ * Going to idle has a significant overhead due to the cache
flush so
+ * try to avoid it if we'll immediately be woken again due to an
IRQ.
+ */
+ if (!need_resched() && !pending) {
+ r4k_blast_dcache();
+
+ __asm__(
+ " .set push \n"
+ " .set mips3 \n"
+ " sync \n"
+ " wait \n"
+ " .set pop \n");
+ }
+
+ local_irq_enable();
+}
+
+/*
* Au1 'wait' is only useful when the 32kHz counter is used as timer,
* since coreclock (and the cp0 counter) stops upon executing it.
Only an
* interrupt can wake it, so they must be enabled before entering
idle modes.
@@ -172,7 +201,6 @@ void __init check_wait(void)
case CPU_CAVIUM_OCTEON_PLUS:
case CPU_CAVIUM_OCTEON2:
case CPU_CAVIUM_OCTEON3:
- case CPU_XBURST:
case CPU_LOONGSON32:
case CPU_XLR:
case CPU_XLP:
@@ -246,6 +274,11 @@ void __init check_wait(void)
cpu_wait = r4k_wait;
*/
break;
+ case CPU_XBURST:
+ if (IS_ENABLED(CONFIG_SMP))
+ cpu_wait = jz4780_smp_wait_irqoff;
+ else
+ cpu_wait = r4k_wait;
default:
break;
}
--
2.7.4
