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-rw-r--r--arch/mips/loongson/Kconfig1
-rw-r--r--arch/mips/loongson/loongson-3/irq.c10
-rw-r--r--arch/mips/loongson/loongson-3/smp.c180
3 files changed, 189 insertions, 2 deletions
diff --git a/arch/mips/loongson/Kconfig b/arch/mips/loongson/Kconfig
index a5d46f5efe03..7397be226a06 100644
--- a/arch/mips/loongson/Kconfig
+++ b/arch/mips/loongson/Kconfig
@@ -79,6 +79,7 @@ config LEMOTE_MACH3A
select SYS_HAS_CPU_LOONGSON3
select SYS_HAS_EARLY_PRINTK
select SYS_SUPPORTS_SMP
+ select SYS_SUPPORTS_HOTPLUG_CPU
select SYS_SUPPORTS_64BIT_KERNEL
select SYS_SUPPORTS_HIGHMEM
select SYS_SUPPORTS_LITTLE_ENDIAN
diff --git a/arch/mips/loongson/loongson-3/irq.c b/arch/mips/loongson/loongson-3/irq.c
index 088fd5e4fd64..f240828181ff 100644
--- a/arch/mips/loongson/loongson-3/irq.c
+++ b/arch/mips/loongson/loongson-3/irq.c
@@ -114,3 +114,13 @@ void __init mach_init_irq(void)
set_c0_status(STATUSF_IP2 | STATUSF_IP6);
}
+
+#ifdef CONFIG_HOTPLUG_CPU
+
+void fixup_irqs(void)
+{
+ irq_cpu_offline();
+ clear_c0_status(ST0_IM);
+}
+
+#endif
diff --git a/arch/mips/loongson/loongson-3/smp.c b/arch/mips/loongson/loongson-3/smp.c
index 93483c25b4b9..c665fe16d4c9 100644
--- a/arch/mips/loongson/loongson-3/smp.c
+++ b/arch/mips/loongson/loongson-3/smp.c
@@ -23,10 +23,14 @@
#include <asm/time.h>
#include <asm/clock.h>
#include <asm/tlbflush.h>
+#include <asm/cacheflush.h>
#include <loongson.h>
#include "smp.h"
+DEFINE_PER_CPU(int, cpu_state);
+DEFINE_PER_CPU(uint32_t, core0_c0count);
+
/* read a 32bit value from ipi register */
#define loongson3_ipi_read32(addr) readl(addr)
/* read a 64bit value from ipi register */
@@ -158,8 +162,8 @@ loongson3_send_ipi_mask(const struct cpumask *mask, unsigned int action)
void loongson3_ipi_interrupt(struct pt_regs *regs)
{
- int cpu = smp_processor_id();
- unsigned int action;
+ int i, cpu = smp_processor_id();
+ unsigned int action, c0count;
/* Load the ipi register to figure out what we're supposed to do */
action = loongson3_ipi_read32(ipi_status0_regs[cpu]);
@@ -172,14 +176,24 @@ void loongson3_ipi_interrupt(struct pt_regs *regs)
if (action & SMP_CALL_FUNCTION)
smp_call_function_interrupt();
+
+ if (action & SMP_ASK_C0COUNT) {
+ BUG_ON(cpu != 0);
+ c0count = read_c0_count();
+ for (i = 1; i < loongson_sysconf.nr_cpus; i++)
+ per_cpu(core0_c0count, i) = c0count;
+ }
}
+#define MAX_LOOPS 1111
/*
* SMP init and finish on secondary CPUs
*/
static void loongson3_init_secondary(void)
{
int i;
+ uint32_t initcount;
+ unsigned int cpu = smp_processor_id();
unsigned int imask = STATUSF_IP7 | STATUSF_IP6 |
STATUSF_IP3 | STATUSF_IP2;
@@ -188,6 +202,21 @@ static void loongson3_init_secondary(void)
for (i = 0; i < loongson_sysconf.nr_cpus; i++)
loongson3_ipi_write32(0xffffffff, ipi_en0_regs[i]);
+
+ per_cpu(cpu_state, cpu) = CPU_ONLINE;
+
+ i = 0;
+ __get_cpu_var(core0_c0count) = 0;
+ loongson3_send_ipi_single(0, SMP_ASK_C0COUNT);
+ while (!__get_cpu_var(core0_c0count)) {
+ i++;
+ cpu_relax();
+ }
+
+ if (i > MAX_LOOPS)
+ i = MAX_LOOPS;
+ initcount = __get_cpu_var(core0_c0count) + i;
+ write_c0_count(initcount);
}
static void loongson3_smp_finish(void)
@@ -222,6 +251,8 @@ static void __init loongson3_smp_setup(void)
static void __init loongson3_prepare_cpus(unsigned int max_cpus)
{
+ init_cpu_present(cpu_possible_mask);
+ per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
}
/*
@@ -255,6 +286,147 @@ static void __init loongson3_cpus_done(void)
{
}
+#ifdef CONFIG_HOTPLUG_CPU
+
+static int loongson3_cpu_disable(void)
+{
+ unsigned long flags;
+ unsigned int cpu = smp_processor_id();
+
+ if (cpu == 0)
+ return -EBUSY;
+
+ set_cpu_online(cpu, false);
+ cpu_clear(cpu, cpu_callin_map);
+ local_irq_save(flags);
+ fixup_irqs();
+ local_irq_restore(flags);
+ flush_cache_all();
+ local_flush_tlb_all();
+
+ return 0;
+}
+
+
+static void loongson3_cpu_die(unsigned int cpu)
+{
+ while (per_cpu(cpu_state, cpu) != CPU_DEAD)
+ cpu_relax();
+
+ mb();
+}
+
+/* To shutdown a core in Loongson 3, the target core should go to CKSEG1 and
+ * flush all L1 entries at first. Then, another core (usually Core 0) can
+ * safely disable the clock of the target core. loongson3_play_dead() is
+ * called via CKSEG1 (uncached and unmmaped) */
+static void loongson3_play_dead(int *state_addr)
+{
+ register int val;
+ register long cpuid, core, node, count;
+ register void *addr, *base, *initfunc;
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set noreorder \n"
+ " li %[addr], 0x80000000 \n" /* KSEG0 */
+ "1: cache 0, 0(%[addr]) \n" /* flush L1 ICache */
+ " cache 0, 1(%[addr]) \n"
+ " cache 0, 2(%[addr]) \n"
+ " cache 0, 3(%[addr]) \n"
+ " cache 1, 0(%[addr]) \n" /* flush L1 DCache */
+ " cache 1, 1(%[addr]) \n"
+ " cache 1, 2(%[addr]) \n"
+ " cache 1, 3(%[addr]) \n"
+ " addiu %[sets], %[sets], -1 \n"
+ " bnez %[sets], 1b \n"
+ " addiu %[addr], %[addr], 0x20 \n"
+ " li %[val], 0x7 \n" /* *state_addr = CPU_DEAD; */
+ " sw %[val], (%[state_addr]) \n"
+ " sync \n"
+ " cache 21, (%[state_addr]) \n" /* flush entry of *state_addr */
+ " .set pop \n"
+ : [addr] "=&r" (addr), [val] "=&r" (val)
+ : [state_addr] "r" (state_addr),
+ [sets] "r" (cpu_data[smp_processor_id()].dcache.sets));
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set noreorder \n"
+ " .set mips64 \n"
+ " mfc0 %[cpuid], $15, 1 \n"
+ " andi %[cpuid], 0x3ff \n"
+ " dli %[base], 0x900000003ff01000 \n"
+ " andi %[core], %[cpuid], 0x3 \n"
+ " sll %[core], 8 \n" /* get core id */
+ " or %[base], %[base], %[core] \n"
+ " andi %[node], %[cpuid], 0xc \n"
+ " dsll %[node], 42 \n" /* get node id */
+ " or %[base], %[base], %[node] \n"
+ "1: li %[count], 0x100 \n" /* wait for init loop */
+ "2: bnez %[count], 2b \n" /* limit mailbox access */
+ " addiu %[count], -1 \n"
+ " ld %[initfunc], 0x20(%[base]) \n" /* get PC via mailbox */
+ " beqz %[initfunc], 1b \n"
+ " nop \n"
+ " ld $sp, 0x28(%[base]) \n" /* get SP via mailbox */
+ " ld $gp, 0x30(%[base]) \n" /* get GP via mailbox */
+ " ld $a1, 0x38(%[base]) \n"
+ " jr %[initfunc] \n" /* jump to initial PC */
+ " nop \n"
+ " .set pop \n"
+ : [core] "=&r" (core), [node] "=&r" (node),
+ [base] "=&r" (base), [cpuid] "=&r" (cpuid),
+ [count] "=&r" (count), [initfunc] "=&r" (initfunc)
+ : /* No Input */
+ : "a1");
+}
+
+void play_dead(void)
+{
+ int *state_addr;
+ unsigned int cpu = smp_processor_id();
+ void (*play_dead_at_ckseg1)(int *);
+
+ idle_task_exit();
+ play_dead_at_ckseg1 =
+ (void *)CKSEG1ADDR((unsigned long)loongson3_play_dead);
+ state_addr = &per_cpu(cpu_state, cpu);
+ mb();
+ play_dead_at_ckseg1(state_addr);
+}
+
+#define CPU_POST_DEAD_FROZEN (CPU_POST_DEAD | CPU_TASKS_FROZEN)
+static int loongson3_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+
+ switch (action) {
+ case CPU_POST_DEAD:
+ case CPU_POST_DEAD_FROZEN:
+ pr_info("Disable clock for CPU#%d\n", cpu);
+ LOONGSON_CHIPCFG0 &= ~(1 << (12 + cpu));
+ break;
+ case CPU_UP_PREPARE:
+ case CPU_UP_PREPARE_FROZEN:
+ pr_info("Enable clock for CPU#%d\n", cpu);
+ LOONGSON_CHIPCFG0 |= 1 << (12 + cpu);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static int register_loongson3_notifier(void)
+{
+ hotcpu_notifier(loongson3_cpu_callback, 0);
+ return 0;
+}
+early_initcall(register_loongson3_notifier);
+
+#endif
+
struct plat_smp_ops loongson3_smp_ops = {
.send_ipi_single = loongson3_send_ipi_single,
.send_ipi_mask = loongson3_send_ipi_mask,
@@ -264,4 +436,8 @@ struct plat_smp_ops loongson3_smp_ops = {
.boot_secondary = loongson3_boot_secondary,
.smp_setup = loongson3_smp_setup,
.prepare_cpus = loongson3_prepare_cpus,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_disable = loongson3_cpu_disable,
+ .cpu_die = loongson3_cpu_die,
+#endif
};
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.