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Diffstat (limited to 'arch/metag/kernel/smp.c')
-rw-r--r--arch/metag/kernel/smp.c175
1 files changed, 133 insertions, 42 deletions
diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c
index 4b6d1f14df3..f006d2276f4 100644
--- a/arch/metag/kernel/smp.c
+++ b/arch/metag/kernel/smp.c
@@ -8,6 +8,7 @@
* published by the Free Software Foundation.
*/
#include <linux/atomic.h>
+#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
@@ -28,6 +29,8 @@
#include <asm/cachepart.h>
#include <asm/core_reg.h>
#include <asm/cpu.h>
+#include <asm/global_lock.h>
+#include <asm/metag_mem.h>
#include <asm/mmu_context.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
@@ -37,6 +40,9 @@
#include <asm/hwthread.h>
#include <asm/traps.h>
+#define SYSC_DCPART(n) (SYSC_DCPART0 + SYSC_xCPARTn_STRIDE * (n))
+#define SYSC_ICPART(n) (SYSC_ICPART0 + SYSC_xCPARTn_STRIDE * (n))
+
DECLARE_PER_CPU(PTBI, pTBI);
void *secondary_data_stack;
@@ -57,10 +63,12 @@ static DEFINE_PER_CPU(struct ipi_data, ipi_data) = {
static DEFINE_SPINLOCK(boot_lock);
+static DECLARE_COMPLETION(cpu_running);
+
/*
* "thread" is assumed to be a valid Meta hardware thread ID.
*/
-int __cpuinit boot_secondary(unsigned int thread, struct task_struct *idle)
+static int boot_secondary(unsigned int thread, struct task_struct *idle)
{
u32 val;
@@ -99,7 +107,113 @@ int __cpuinit boot_secondary(unsigned int thread, struct task_struct *idle)
return 0;
}
-int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
+/**
+ * describe_cachepart_change: describe a change to cache partitions.
+ * @thread: Hardware thread number.
+ * @label: Label of cache type, e.g. "dcache" or "icache".
+ * @sz: Total size of the cache.
+ * @old: Old cache partition configuration (*CPART* register).
+ * @new: New cache partition configuration (*CPART* register).
+ *
+ * If the cache partition has changed, prints a message to the log describing
+ * those changes.
+ */
+static void describe_cachepart_change(unsigned int thread, const char *label,
+ unsigned int sz, unsigned int old,
+ unsigned int new)
+{
+ unsigned int lor1, land1, gor1, gand1;
+ unsigned int lor2, land2, gor2, gand2;
+ unsigned int diff = old ^ new;
+
+ if (!diff)
+ return;
+
+ pr_info("Thread %d: %s partition changed:", thread, label);
+ if (diff & (SYSC_xCPARTL_OR_BITS | SYSC_xCPARTL_AND_BITS)) {
+ lor1 = (old & SYSC_xCPARTL_OR_BITS) >> SYSC_xCPARTL_OR_S;
+ lor2 = (new & SYSC_xCPARTL_OR_BITS) >> SYSC_xCPARTL_OR_S;
+ land1 = (old & SYSC_xCPARTL_AND_BITS) >> SYSC_xCPARTL_AND_S;
+ land2 = (new & SYSC_xCPARTL_AND_BITS) >> SYSC_xCPARTL_AND_S;
+ pr_cont(" L:%#x+%#x->%#x+%#x",
+ (lor1 * sz) >> 4,
+ ((land1 + 1) * sz) >> 4,
+ (lor2 * sz) >> 4,
+ ((land2 + 1) * sz) >> 4);
+ }
+ if (diff & (SYSC_xCPARTG_OR_BITS | SYSC_xCPARTG_AND_BITS)) {
+ gor1 = (old & SYSC_xCPARTG_OR_BITS) >> SYSC_xCPARTG_OR_S;
+ gor2 = (new & SYSC_xCPARTG_OR_BITS) >> SYSC_xCPARTG_OR_S;
+ gand1 = (old & SYSC_xCPARTG_AND_BITS) >> SYSC_xCPARTG_AND_S;
+ gand2 = (new & SYSC_xCPARTG_AND_BITS) >> SYSC_xCPARTG_AND_S;
+ pr_cont(" G:%#x+%#x->%#x+%#x",
+ (gor1 * sz) >> 4,
+ ((gand1 + 1) * sz) >> 4,
+ (gor2 * sz) >> 4,
+ ((gand2 + 1) * sz) >> 4);
+ }
+ if (diff & SYSC_CWRMODE_BIT)
+ pr_cont(" %sWR",
+ (new & SYSC_CWRMODE_BIT) ? "+" : "-");
+ if (diff & SYSC_DCPART_GCON_BIT)
+ pr_cont(" %sGCOn",
+ (new & SYSC_DCPART_GCON_BIT) ? "+" : "-");
+ pr_cont("\n");
+}
+
+/**
+ * setup_smp_cache: ensure cache coherency for new SMP thread.
+ * @thread: New hardware thread number.
+ *
+ * Ensures that coherency is enabled and that the threads share the same cache
+ * partitions.
+ */
+static void setup_smp_cache(unsigned int thread)
+{
+ unsigned int this_thread, lflags;
+ unsigned int dcsz, dcpart_this, dcpart_old, dcpart_new;
+ unsigned int icsz, icpart_old, icpart_new;
+
+ /*
+ * Copy over the current thread's cache partition configuration to the
+ * new thread so that they share cache partitions.
+ */
+ __global_lock2(lflags);
+ this_thread = hard_processor_id();
+ /* Share dcache partition */
+ dcpart_this = metag_in32(SYSC_DCPART(this_thread));
+ dcpart_old = metag_in32(SYSC_DCPART(thread));
+ dcpart_new = dcpart_this;
+#if PAGE_OFFSET < LINGLOBAL_BASE
+ /*
+ * For the local data cache to be coherent the threads must also have
+ * GCOn enabled.
+ */
+ dcpart_new |= SYSC_DCPART_GCON_BIT;
+ metag_out32(dcpart_new, SYSC_DCPART(this_thread));
+#endif
+ metag_out32(dcpart_new, SYSC_DCPART(thread));
+ /* Share icache partition too */
+ icpart_new = metag_in32(SYSC_ICPART(this_thread));
+ icpart_old = metag_in32(SYSC_ICPART(thread));
+ metag_out32(icpart_new, SYSC_ICPART(thread));
+ __global_unlock2(lflags);
+
+ /*
+ * Log if the cache partitions were altered so the user is aware of any
+ * potential unintentional cache wastage.
+ */
+ dcsz = get_dcache_size();
+ icsz = get_dcache_size();
+ describe_cachepart_change(this_thread, "dcache", dcsz,
+ dcpart_this, dcpart_new);
+ describe_cachepart_change(thread, "dcache", dcsz,
+ dcpart_old, dcpart_new);
+ describe_cachepart_change(thread, "icache", icsz,
+ icpart_old, icpart_new);
+}
+
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
{
unsigned int thread = cpu_2_hwthread_id[cpu];
int ret;
@@ -108,6 +222,8 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
flush_tlb_all();
+ setup_smp_cache(thread);
+
/*
* Tell the secondary CPU where to find its idle thread's stack.
*/
@@ -120,20 +236,12 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
*/
ret = boot_secondary(thread, idle);
if (ret == 0) {
- unsigned long timeout;
-
/*
* CPU was successfully started, wait for it
* to come online or time out.
*/
- timeout = jiffies + HZ;
- while (time_before(jiffies, timeout)) {
- if (cpu_online(cpu))
- break;
-
- udelay(10);
- barrier();
- }
+ wait_for_completion_timeout(&cpu_running,
+ msecs_to_jiffies(1000));
if (!cpu_online(cpu))
ret = -EIO;
@@ -158,10 +266,9 @@ static DECLARE_COMPLETION(cpu_killed);
/*
* __cpu_disable runs on the processor to be shutdown.
*/
-int __cpuexit __cpu_disable(void)
+int __cpu_disable(void)
{
unsigned int cpu = smp_processor_id();
- struct task_struct *p;
/*
* Take this CPU offline. Once we clear this, we can't return,
@@ -181,12 +288,7 @@ int __cpuexit __cpu_disable(void)
flush_cache_all();
local_flush_tlb_all();
- read_lock(&tasklist_lock);
- for_each_process(p) {
- if (p->mm)
- cpumask_clear_cpu(cpu, mm_cpumask(p->mm));
- }
- read_unlock(&tasklist_lock);
+ clear_tasks_mm_cpumask(cpu);
return 0;
}
@@ -195,7 +297,7 @@ int __cpuexit __cpu_disable(void)
* called on the thread which is asking for a CPU to be shutdown -
* waits until shutdown has completed, or it is timed out.
*/
-void __cpuexit __cpu_die(unsigned int cpu)
+void __cpu_die(unsigned int cpu)
{
if (!wait_for_completion_timeout(&cpu_killed, msecs_to_jiffies(1)))
pr_err("CPU%u: unable to kill\n", cpu);
@@ -207,7 +309,7 @@ void __cpuexit __cpu_die(unsigned int cpu)
* Note that we do not return from this function. If this cpu is
* brought online again it will need to run secondary_startup().
*/
-void __cpuexit cpu_die(void)
+void cpu_die(void)
{
local_irq_disable();
idle_task_exit();
@@ -222,7 +324,7 @@ void __cpuexit cpu_die(void)
* Called by both boot and secondaries to move global data into
* per-processor storage.
*/
-void __cpuinit smp_store_cpu_info(unsigned int cpuid)
+void smp_store_cpu_info(unsigned int cpuid)
{
struct cpuinfo_metag *cpu_info = &per_cpu(cpu_data, cpuid);
@@ -270,12 +372,7 @@ asmlinkage void secondary_start_kernel(void)
setup_priv();
- /*
- * Enable local interrupts.
- */
- tbi_startup_interrupt(TBID_SIGNUM_TRT);
notify_cpu_starting(cpu);
- local_irq_enable();
pr_info("CPU%u (thread %u): Booted secondary processor\n",
cpu, cpu_2_hwthread_id[cpu]);
@@ -287,17 +384,18 @@ asmlinkage void secondary_start_kernel(void)
* OK, now it's safe to let the boot CPU continue
*/
set_cpu_online(cpu, true);
+ complete(&cpu_running);
/*
- * Check for cache aliasing.
- * Preemption is disabled
+ * Enable local interrupts.
*/
- check_for_cache_aliasing(cpu);
+ tbi_startup_interrupt(TBID_SIGNUM_TRT);
+ local_irq_enable();
/*
* OK, it's off to the idle thread for us
*/
- cpu_idle();
+ cpu_startup_entry(CPUHP_ONLINE);
}
void __init smp_cpus_done(unsigned int max_cpus)
@@ -393,7 +491,7 @@ void arch_send_call_function_ipi_mask(const struct cpumask *mask)
void arch_send_call_function_single_ipi(int cpu)
{
- send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
+ send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC);
}
void show_ipi_list(struct seq_file *p)
@@ -419,11 +517,10 @@ static DEFINE_SPINLOCK(stop_lock);
*
* Bit 0 - Inter-processor function call
*/
-static int do_IPI(struct pt_regs *regs)
+static int do_IPI(void)
{
unsigned int cpu = smp_processor_id();
struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
- struct pt_regs *old_regs = set_irq_regs(regs);
unsigned long msgs, nextmsg;
int handled = 0;
@@ -448,10 +545,6 @@ static int do_IPI(struct pt_regs *regs)
generic_smp_call_function_interrupt();
break;
- case IPI_CALL_FUNC_SINGLE:
- generic_smp_call_function_single_interrupt();
- break;
-
default:
pr_crit("CPU%u: Unknown IPI message 0x%lx\n",
cpu, nextmsg);
@@ -459,8 +552,6 @@ static int do_IPI(struct pt_regs *regs)
}
}
- set_irq_regs(old_regs);
-
return handled;
}
@@ -526,7 +617,7 @@ static void kick_raise_softirq(cpumask_t callmap, unsigned int irq)
static TBIRES ipi_handler(TBIRES State, int SigNum, int Triggers,
int Inst, PTBI pTBI, int *handled)
{
- *handled = do_IPI((struct pt_regs *)State.Sig.pCtx);
+ *handled = do_IPI();
return State;
}