#include <asm/mips-cpc.h>
#include <asm/mips_mt.h>
#include <asm/mipsregs.h>
+#include <asm/pm-cps.h>
#include <asm/smp-cps.h>
#include <asm/time.h>
#include <asm/uasm.h>
static DECLARE_BITMAP(core_power, NR_CPUS);
-struct boot_config mips_cps_bootcfg;
+struct core_boot_config *mips_cps_core_bootcfg;
-static void init_core(void)
+static unsigned core_vpe_count(unsigned core)
{
- unsigned int nvpes, t;
- u32 mvpconf0, vpeconf0, vpecontrol, tcstatus, tcbind, status;
+ unsigned cfg;
- if (!cpu_has_mipsmt)
- return;
-
- /* Enter VPE configuration state */
- dvpe();
- set_c0_mvpcontrol(MVPCONTROL_VPC);
-
- /* Retrieve the count of VPEs in this core */
- mvpconf0 = read_c0_mvpconf0();
- nvpes = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
- smp_num_siblings = nvpes;
-
- for (t = 1; t < nvpes; t++) {
- /* Use a 1:1 mapping of TC index to VPE index */
- settc(t);
-
- /* Bind 1 TC to this VPE */
- tcbind = read_tc_c0_tcbind();
- tcbind &= ~TCBIND_CURVPE;
- tcbind |= t << TCBIND_CURVPE_SHIFT;
- write_tc_c0_tcbind(tcbind);
-
- /* Set exclusive TC, non-active, master */
- vpeconf0 = read_vpe_c0_vpeconf0();
- vpeconf0 &= ~(VPECONF0_XTC | VPECONF0_VPA);
- vpeconf0 |= t << VPECONF0_XTC_SHIFT;
- vpeconf0 |= VPECONF0_MVP;
- write_vpe_c0_vpeconf0(vpeconf0);
-
- /* Declare TC non-active, non-allocatable & interrupt exempt */
- tcstatus = read_tc_c0_tcstatus();
- tcstatus &= ~(TCSTATUS_A | TCSTATUS_DA);
- tcstatus |= TCSTATUS_IXMT;
- write_tc_c0_tcstatus(tcstatus);
-
- /* Halt the TC */
- write_tc_c0_tchalt(TCHALT_H);
-
- /* Allow only 1 TC to execute */
- vpecontrol = read_vpe_c0_vpecontrol();
- vpecontrol &= ~VPECONTROL_TE;
- write_vpe_c0_vpecontrol(vpecontrol);
-
- /* Copy (most of) Status from VPE 0 */
- status = read_c0_status();
- status &= ~(ST0_IM | ST0_IE | ST0_KSU);
- status |= ST0_CU0;
- write_vpe_c0_status(status);
-
- /* Copy Config from VPE 0 */
- write_vpe_c0_config(read_c0_config());
- write_vpe_c0_config7(read_c0_config7());
-
- /* Ensure no software interrupts are pending */
- write_vpe_c0_cause(0);
-
- /* Sync Count */
- write_vpe_c0_count(read_c0_count());
- }
+ if (!config_enabled(CONFIG_MIPS_MT_SMP) || !cpu_has_mipsmt)
+ return 1;
- /* Leave VPE configuration state */
- clear_c0_mvpcontrol(MVPCONTROL_VPC);
+ write_gcr_cl_other(core << CM_GCR_Cx_OTHER_CORENUM_SHF);
+ cfg = read_gcr_co_config() & CM_GCR_Cx_CONFIG_PVPE_MSK;
+ return (cfg >> CM_GCR_Cx_CONFIG_PVPE_SHF) + 1;
}
static void __init cps_smp_setup(void)
{
unsigned int ncores, nvpes, core_vpes;
int c, v;
- u32 core_cfg, *entry_code;
/* Detect & record VPE topology */
ncores = mips_cm_numcores();
pr_info("VPE topology ");
for (c = nvpes = 0; c < ncores; c++) {
- if (cpu_has_mipsmt && config_enabled(CONFIG_MIPS_MT_SMP)) {
- write_gcr_cl_other(c << CM_GCR_Cx_OTHER_CORENUM_SHF);
- core_cfg = read_gcr_co_config();
- core_vpes = ((core_cfg & CM_GCR_Cx_CONFIG_PVPE_MSK) >>
- CM_GCR_Cx_CONFIG_PVPE_SHF) + 1;
- } else {
- core_vpes = 1;
- }
-
+ core_vpes = core_vpe_count(c);
pr_cont("%c%u", c ? ',' : '{', core_vpes);
+ /* Use the number of VPEs in core 0 for smp_num_siblings */
+ if (!c)
+ smp_num_siblings = core_vpes;
+
for (v = 0; v < min_t(int, core_vpes, NR_CPUS - nvpes); v++) {
cpu_data[nvpes + v].core = c;
#ifdef CONFIG_MIPS_MT_SMP
/* Core 0 is powered up (we're running on it) */
bitmap_set(core_power, 0, 1);
- /* Disable MT - we only want to run 1 TC per VPE */
- if (cpu_has_mipsmt)
- dmt();
-
/* Initialise core 0 */
- init_core();
-
- /* Patch the start of mips_cps_core_entry to provide the CM base */
- entry_code = (u32 *)&mips_cps_core_entry;
- UASM_i_LA(&entry_code, 3, (long)mips_cm_base);
+ mips_cps_core_init();
/* Make core 0 coherent with everything */
write_gcr_cl_coherence(0xff);
static void __init cps_prepare_cpus(unsigned int max_cpus)
{
+ unsigned ncores, core_vpes, c;
+ u32 *entry_code;
+
mips_mt_set_cpuoptions();
+
+ /* Patch the start of mips_cps_core_entry to provide the CM base */
+ entry_code = (u32 *)&mips_cps_core_entry;
+ UASM_i_LA(&entry_code, 3, (long)mips_cm_base);
+ dma_cache_wback_inv((unsigned long)&mips_cps_core_entry,
+ (void *)entry_code - (void *)&mips_cps_core_entry);
+
+ /* Allocate core boot configuration structs */
+ ncores = mips_cm_numcores();
+ mips_cps_core_bootcfg = kcalloc(ncores, sizeof(*mips_cps_core_bootcfg),
+ GFP_KERNEL);
+ if (!mips_cps_core_bootcfg) {
+ pr_err("Failed to allocate boot config for %u cores\n", ncores);
+ goto err_out;
+ }
+
+ /* Allocate VPE boot configuration structs */
+ for (c = 0; c < ncores; c++) {
+ core_vpes = core_vpe_count(c);
+ mips_cps_core_bootcfg[c].vpe_config = kcalloc(core_vpes,
+ sizeof(*mips_cps_core_bootcfg[c].vpe_config),
+ GFP_KERNEL);
+ if (!mips_cps_core_bootcfg[c].vpe_config) {
+ pr_err("Failed to allocate %u VPE boot configs\n",
+ core_vpes);
+ goto err_out;
+ }
+ }
+
+ /* Mark this CPU as booted */
+ atomic_set(&mips_cps_core_bootcfg[current_cpu_data.core].vpe_mask,
+ 1 << cpu_vpe_id(¤t_cpu_data));
+
+ return;
+err_out:
+ /* Clean up allocations */
+ if (mips_cps_core_bootcfg) {
+ for (c = 0; c < ncores; c++)
+ kfree(mips_cps_core_bootcfg[c].vpe_config);
+ kfree(mips_cps_core_bootcfg);
+ mips_cps_core_bootcfg = NULL;
+ }
+
+ /* Effectively disable SMP by declaring CPUs not present */
+ for_each_possible_cpu(c) {
+ if (c == 0)
+ continue;
+ set_cpu_present(c, false);
+ }
}
-static void boot_core(struct boot_config *cfg)
+static void boot_core(unsigned core)
{
u32 access;
/* Select the appropriate core */
- write_gcr_cl_other(cfg->core << CM_GCR_Cx_OTHER_CORENUM_SHF);
+ write_gcr_cl_other(core << CM_GCR_Cx_OTHER_CORENUM_SHF);
/* Set its reset vector */
write_gcr_co_reset_base(CKSEG1ADDR((unsigned long)mips_cps_core_entry));
/* Ensure the core can access the GCRs */
access = read_gcr_access();
- access |= 1 << (CM_GCR_ACCESS_ACCESSEN_SHF + cfg->core);
+ access |= 1 << (CM_GCR_ACCESS_ACCESSEN_SHF + core);
write_gcr_access(access);
- /* Copy cfg */
- mips_cps_bootcfg = *cfg;
-
if (mips_cpc_present()) {
- /* Select the appropriate core */
- write_cpc_cl_other(cfg->core << CPC_Cx_OTHER_CORENUM_SHF);
-
/* Reset the core */
+ mips_cpc_lock_other(core);
write_cpc_co_cmd(CPC_Cx_CMD_RESET);
+ mips_cpc_unlock_other();
} else {
/* Take the core out of reset */
write_gcr_co_reset_release(0);
}
/* The core is now powered up */
- bitmap_set(core_power, cfg->core, 1);
+ bitmap_set(core_power, core, 1);
}
-static void boot_vpe(void *info)
+static void remote_vpe_boot(void *dummy)
{
- struct boot_config *cfg = info;
- u32 tcstatus, vpeconf0;
-
- /* Enter VPE configuration state */
- dvpe();
- set_c0_mvpcontrol(MVPCONTROL_VPC);
-
- settc(cfg->vpe);
-
- /* Set the TC restart PC */
- write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
-
- /* Activate the TC, allow interrupts */
- tcstatus = read_tc_c0_tcstatus();
- tcstatus &= ~TCSTATUS_IXMT;
- tcstatus |= TCSTATUS_A;
- write_tc_c0_tcstatus(tcstatus);
-
- /* Clear the TC halt bit */
- write_tc_c0_tchalt(0);
-
- /* Activate the VPE */
- vpeconf0 = read_vpe_c0_vpeconf0();
- vpeconf0 |= VPECONF0_VPA;
- write_vpe_c0_vpeconf0(vpeconf0);
-
- /* Set the stack & global pointer registers */
- write_tc_gpr_sp(cfg->sp);
- write_tc_gpr_gp(cfg->gp);
-
- /* Leave VPE configuration state */
- clear_c0_mvpcontrol(MVPCONTROL_VPC);
-
- /* Enable other VPEs to execute */
- evpe(EVPE_ENABLE);
+ mips_cps_boot_vpes();
}
static void cps_boot_secondary(int cpu, struct task_struct *idle)
{
- struct boot_config cfg;
+ unsigned core = cpu_data[cpu].core;
+ unsigned vpe_id = cpu_vpe_id(&cpu_data[cpu]);
+ struct core_boot_config *core_cfg = &mips_cps_core_bootcfg[core];
+ struct vpe_boot_config *vpe_cfg = &core_cfg->vpe_config[vpe_id];
unsigned int remote;
int err;
- cfg.core = cpu_data[cpu].core;
- cfg.vpe = cpu_vpe_id(&cpu_data[cpu]);
- cfg.pc = (unsigned long)&smp_bootstrap;
- cfg.sp = __KSTK_TOS(idle);
- cfg.gp = (unsigned long)task_thread_info(idle);
+ vpe_cfg->pc = (unsigned long)&smp_bootstrap;
+ vpe_cfg->sp = __KSTK_TOS(idle);
+ vpe_cfg->gp = (unsigned long)task_thread_info(idle);
+
+ atomic_or(1 << cpu_vpe_id(&cpu_data[cpu]), &core_cfg->vpe_mask);
+
+ preempt_disable();
- if (!test_bit(cfg.core, core_power)) {
+ if (!test_bit(core, core_power)) {
/* Boot a VPE on a powered down core */
- boot_core(&cfg);
- return;
+ boot_core(core);
+ goto out;
}
- if (cfg.core != current_cpu_data.core) {
+ if (core != current_cpu_data.core) {
/* Boot a VPE on another powered up core */
for (remote = 0; remote < NR_CPUS; remote++) {
- if (cpu_data[remote].core != cfg.core)
+ if (cpu_data[remote].core != core)
continue;
if (cpu_online(remote))
break;
}
BUG_ON(remote >= NR_CPUS);
- err = smp_call_function_single(remote, boot_vpe, &cfg, 1);
+ err = smp_call_function_single(remote, remote_vpe_boot,
+ NULL, 1);
if (err)
panic("Failed to call remote CPU\n");
- return;
+ goto out;
}
BUG_ON(!cpu_has_mipsmt);
/* Boot a VPE on this core */
- boot_vpe(&cfg);
+ mips_cps_boot_vpes();
+out:
+ preempt_enable();
}
static void cps_init_secondary(void)
if (cpu_has_mipsmt)
dmt();
- /* TODO: revisit this assumption once hotplug is implemented */
- if (cpu_vpe_id(¤t_cpu_data) == 0)
- init_core();
-
change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 |
STATUSF_IP6 | STATUSF_IP7);
}
{
}
+#ifdef CONFIG_HOTPLUG_CPU
+
+static int cps_cpu_disable(void)
+{
+ unsigned cpu = smp_processor_id();
+ struct core_boot_config *core_cfg;
+
+ if (!cpu)
+ return -EBUSY;
+
+ if (!cps_pm_support_state(CPS_PM_POWER_GATED))
+ return -EINVAL;
+
+ core_cfg = &mips_cps_core_bootcfg[current_cpu_data.core];
+ atomic_sub(1 << cpu_vpe_id(¤t_cpu_data), &core_cfg->vpe_mask);
+ smp_mb__after_atomic_dec();
+ set_cpu_online(cpu, false);
+ cpu_clear(cpu, cpu_callin_map);
+
+ return 0;
+}
+
+static DECLARE_COMPLETION(cpu_death_chosen);
+static unsigned cpu_death_sibling;
+static enum {
+ CPU_DEATH_HALT,
+ CPU_DEATH_POWER,
+} cpu_death;
+
+void play_dead(void)
+{
+ unsigned cpu, core;
+
+ local_irq_disable();
+ idle_task_exit();
+ cpu = smp_processor_id();
+ cpu_death = CPU_DEATH_POWER;
+
+ if (cpu_has_mipsmt) {
+ core = cpu_data[cpu].core;
+
+ /* Look for another online VPE within the core */
+ for_each_online_cpu(cpu_death_sibling) {
+ if (cpu_data[cpu_death_sibling].core != core)
+ continue;
+
+ /*
+ * There is an online VPE within the core. Just halt
+ * this TC and leave the core alone.
+ */
+ cpu_death = CPU_DEATH_HALT;
+ break;
+ }
+ }
+
+ /* This CPU has chosen its way out */
+ complete(&cpu_death_chosen);
+
+ if (cpu_death == CPU_DEATH_HALT) {
+ /* Halt this TC */
+ write_c0_tchalt(TCHALT_H);
+ instruction_hazard();
+ } else {
+ /* Power down the core */
+ cps_pm_enter_state(CPS_PM_POWER_GATED);
+ }
+
+ /* This should never be reached */
+ panic("Failed to offline CPU %u", cpu);
+}
+
+static void wait_for_sibling_halt(void *ptr_cpu)
+{
+ unsigned cpu = (unsigned)ptr_cpu;
+ unsigned vpe_id = cpu_data[cpu].vpe_id;
+ unsigned halted;
+ unsigned long flags;
+
+ do {
+ local_irq_save(flags);
+ settc(vpe_id);
+ halted = read_tc_c0_tchalt();
+ local_irq_restore(flags);
+ } while (!(halted & TCHALT_H));
+}
+
+static void cps_cpu_die(unsigned int cpu)
+{
+ unsigned core = cpu_data[cpu].core;
+ unsigned stat;
+ int err;
+
+ /* Wait for the cpu to choose its way out */
+ if (!wait_for_completion_timeout(&cpu_death_chosen,
+ msecs_to_jiffies(5000))) {
+ pr_err("CPU%u: didn't offline\n", cpu);
+ return;
+ }
+
+ /*
+ * Now wait for the CPU to actually offline. Without doing this that
+ * offlining may race with one or more of:
+ *
+ * - Onlining the CPU again.
+ * - Powering down the core if another VPE within it is offlined.
+ * - A sibling VPE entering a non-coherent state.
+ *
+ * In the non-MT halt case (ie. infinite loop) the CPU is doing nothing
+ * with which we could race, so do nothing.
+ */
+ if (cpu_death == CPU_DEATH_POWER) {
+ /*
+ * Wait for the core to enter a powered down or clock gated
+ * state, the latter happening when a JTAG probe is connected
+ * in which case the CPC will refuse to power down the core.
+ */
+ do {
+ mips_cpc_lock_other(core);
+ stat = read_cpc_co_stat_conf();
+ stat &= CPC_Cx_STAT_CONF_SEQSTATE_MSK;
+ mips_cpc_unlock_other();
+ } while (stat != CPC_Cx_STAT_CONF_SEQSTATE_D0 &&
+ stat != CPC_Cx_STAT_CONF_SEQSTATE_D2 &&
+ stat != CPC_Cx_STAT_CONF_SEQSTATE_U2);
+
+ /* Indicate the core is powered off */
+ bitmap_clear(core_power, core, 1);
+ } else if (cpu_has_mipsmt) {
+ /*
+ * Have a CPU with access to the offlined CPUs registers wait
+ * for its TC to halt.
+ */
+ err = smp_call_function_single(cpu_death_sibling,
+ wait_for_sibling_halt,
+ (void *)cpu, 1);
+ if (err)
+ panic("Failed to call remote sibling CPU\n");
+ }
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
static struct plat_smp_ops cps_smp_ops = {
.smp_setup = cps_smp_setup,
.prepare_cpus = cps_prepare_cpus,
.send_ipi_single = gic_send_ipi_single,
.send_ipi_mask = gic_send_ipi_mask,
.cpus_done = cps_cpus_done,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_disable = cps_cpu_disable,
+ .cpu_die = cps_cpu_die,
+#endif
};
+bool mips_cps_smp_in_use(void)
+{
+ extern struct plat_smp_ops *mp_ops;
+ return mp_ops == &cps_smp_ops;
+}
+
int register_cps_smp_ops(void)
{
if (!mips_cm_present()) {
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