182 lines
4.2 KiB
C
182 lines
4.2 KiB
C
#include <linux/linkage.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <asm/pmon.h>
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#include <asm/titan_dep.h>
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#include <asm/time.h>
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#define LAUNCHSTACK_SIZE 256
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static __cpuinitdata arch_spinlock_t launch_lock = __ARCH_SPIN_LOCK_UNLOCKED;
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static unsigned long secondary_sp __cpuinitdata;
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static unsigned long secondary_gp __cpuinitdata;
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static unsigned char launchstack[LAUNCHSTACK_SIZE] __initdata
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__attribute__((aligned(2 * sizeof(long))));
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static void __init prom_smp_bootstrap(void)
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{
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local_irq_disable();
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while (arch_spin_is_locked(&launch_lock));
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__asm__ __volatile__(
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" move $sp, %0 \n"
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" move $gp, %1 \n"
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" j smp_bootstrap \n"
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:
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: "r" (secondary_sp), "r" (secondary_gp));
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}
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/*
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* PMON is a fragile beast. It'll blow up once the mappings it's littering
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* right into the middle of KSEG3 are blown away so we have to grab the slave
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* core early and keep it in a waiting loop.
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*/
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void __init prom_grab_secondary(void)
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{
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arch_spin_lock(&launch_lock);
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pmon_cpustart(1, &prom_smp_bootstrap,
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launchstack + LAUNCHSTACK_SIZE, 0);
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}
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void titan_mailbox_irq(void)
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{
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int cpu = smp_processor_id();
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unsigned long status;
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switch (cpu) {
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case 0:
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status = OCD_READ(RM9000x2_OCD_INTP0STATUS3);
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OCD_WRITE(RM9000x2_OCD_INTP0CLEAR3, status);
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if (status & 0x2)
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smp_call_function_interrupt();
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break;
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case 1:
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status = OCD_READ(RM9000x2_OCD_INTP1STATUS3);
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OCD_WRITE(RM9000x2_OCD_INTP1CLEAR3, status);
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if (status & 0x2)
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smp_call_function_interrupt();
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break;
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}
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}
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/*
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* Send inter-processor interrupt
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*/
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static void yos_send_ipi_single(int cpu, unsigned int action)
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{
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/*
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* Generate an INTMSG so that it can be sent over to the
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* destination CPU. The INTMSG will put the STATUS bits
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* based on the action desired. An alternative strategy
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* is to write to the Interrupt Set register, read the
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* Interrupt Status register and clear the Interrupt
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* Clear register. The latter is preffered.
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*/
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switch (action) {
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case SMP_RESCHEDULE_YOURSELF:
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if (cpu == 1)
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OCD_WRITE(RM9000x2_OCD_INTP1SET3, 4);
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else
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OCD_WRITE(RM9000x2_OCD_INTP0SET3, 4);
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break;
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case SMP_CALL_FUNCTION:
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if (cpu == 1)
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OCD_WRITE(RM9000x2_OCD_INTP1SET3, 2);
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else
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OCD_WRITE(RM9000x2_OCD_INTP0SET3, 2);
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break;
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}
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}
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static void yos_send_ipi_mask(const struct cpumask *mask, unsigned int action)
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{
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unsigned int i;
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for_each_cpu(i, mask)
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yos_send_ipi_single(i, action);
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}
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/*
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* After we've done initial boot, this function is called to allow the
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* board code to clean up state, if needed
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*/
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static void __cpuinit yos_init_secondary(void)
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{
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set_c0_status(ST0_CO | ST0_IE | ST0_IM);
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}
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static void __cpuinit yos_smp_finish(void)
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{
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}
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/* Hook for after all CPUs are online */
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static void yos_cpus_done(void)
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{
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}
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/*
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* Firmware CPU startup hook
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* Complicated by PMON's weird interface which tries to minimic the UNIX fork.
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* It launches the next * available CPU and copies some information on the
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* stack so the first thing we do is throw away that stuff and load useful
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* values into the registers ...
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*/
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static void __cpuinit yos_boot_secondary(int cpu, struct task_struct *idle)
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{
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unsigned long gp = (unsigned long) task_thread_info(idle);
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unsigned long sp = __KSTK_TOS(idle);
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secondary_sp = sp;
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secondary_gp = gp;
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arch_spin_unlock(&launch_lock);
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}
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/*
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* Detect available CPUs, populate cpu_possible_map before smp_init
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*
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* We don't want to start the secondary CPU yet nor do we have a nice probing
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* feature in PMON so we just assume presence of the secondary core.
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*/
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static void __init yos_smp_setup(void)
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{
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int i;
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cpus_clear(cpu_possible_map);
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for (i = 0; i < 2; i++) {
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cpu_set(i, cpu_possible_map);
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__cpu_number_map[i] = i;
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__cpu_logical_map[i] = i;
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}
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}
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static void __init yos_prepare_cpus(unsigned int max_cpus)
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{
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/*
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* Be paranoid. Enable the IPI only if we're really about to go SMP.
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*/
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if (cpus_weight(cpu_possible_map))
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set_c0_status(STATUSF_IP5);
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}
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struct plat_smp_ops yos_smp_ops = {
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.send_ipi_single = yos_send_ipi_single,
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.send_ipi_mask = yos_send_ipi_mask,
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.init_secondary = yos_init_secondary,
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.smp_finish = yos_smp_finish,
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.cpus_done = yos_cpus_done,
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.boot_secondary = yos_boot_secondary,
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.smp_setup = yos_smp_setup,
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.prepare_cpus = yos_prepare_cpus,
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};
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