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#include <linux/linkage.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <asm/pmon.h>
#include <asm/titan_dep.h>
#include <asm/time.h>
#define LAUNCHSTACK_SIZE 256
static __cpuinitdata arch_spinlock_t launch_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static unsigned long secondary_sp __cpuinitdata;
static unsigned long secondary_gp __cpuinitdata;
static unsigned char launchstack[LAUNCHSTACK_SIZE] __initdata
__attribute__((aligned(2 * sizeof(long))));
static void __init prom_smp_bootstrap(void)
{
local_irq_disable();
while (arch_spin_is_locked(&launch_lock));
__asm__ __volatile__(
" move $sp, %0 \n"
" move $gp, %1 \n"
" j smp_bootstrap \n"
:
: "r" (secondary_sp), "r" (secondary_gp));
}
/*
* PMON is a fragile beast. It'll blow up once the mappings it's littering
* right into the middle of KSEG3 are blown away so we have to grab the slave
* core early and keep it in a waiting loop.
*/
void __init prom_grab_secondary(void)
{
arch_spin_lock(&launch_lock);
pmon_cpustart(1, &prom_smp_bootstrap,
launchstack + LAUNCHSTACK_SIZE, 0);
}
void titan_mailbox_irq(void)
{
int cpu = smp_processor_id();
unsigned long status;
switch (cpu) {
case 0:
status = OCD_READ(RM9000x2_OCD_INTP0STATUS3);
OCD_WRITE(RM9000x2_OCD_INTP0CLEAR3, status);
if (status & 0x2)
smp_call_function_interrupt();
if (status & 0x4)
scheduler_ipi();
break;
case 1:
status = OCD_READ(RM9000x2_OCD_INTP1STATUS3);
OCD_WRITE(RM9000x2_OCD_INTP1CLEAR3, status);
if (status & 0x2)
smp_call_function_interrupt();
if (status & 0x4)
scheduler_ipi();
break;
}
}
/*
* Send inter-processor interrupt
*/
static void yos_send_ipi_single(int cpu, unsigned int action)
{
/*
* Generate an INTMSG so that it can be sent over to the
* destination CPU. The INTMSG will put the STATUS bits
* based on the action desired. An alternative strategy
* is to write to the Interrupt Set register, read the
* Interrupt Status register and clear the Interrupt
* Clear register. The latter is preffered.
*/
switch (action) {
case SMP_RESCHEDULE_YOURSELF:
if (cpu == 1)
OCD_WRITE(RM9000x2_OCD_INTP1SET3, 4);
else
OCD_WRITE(RM9000x2_OCD_INTP0SET3, 4);
break;
case SMP_CALL_FUNCTION:
if (cpu == 1)
OCD_WRITE(RM9000x2_OCD_INTP1SET3, 2);
else
OCD_WRITE(RM9000x2_OCD_INTP0SET3, 2);
break;
}
}
static void yos_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
unsigned int i;
for_each_cpu(i, mask)
yos_send_ipi_single(i, action);
}
/*
* After we've done initial boot, this function is called to allow the
* board code to clean up state, if needed
*/
static void __cpuinit yos_init_secondary(void)
{
}
static void __cpuinit yos_smp_finish(void)
{
set_c0_status(ST0_CO | ST0_IM | ST0_IE);
}
/* Hook for after all CPUs are online */
static void yos_cpus_done(void)
{
}
/*
* Firmware CPU startup hook
* Complicated by PMON's weird interface which tries to minimic the UNIX fork.
* It launches the next * available CPU and copies some information on the
* stack so the first thing we do is throw away that stuff and load useful
* values into the registers ...
*/
static void __cpuinit yos_boot_secondary(int cpu, struct task_struct *idle)
{
unsigned long gp = (unsigned long) task_thread_info(idle);
unsigned long sp = __KSTK_TOS(idle);
secondary_sp = sp;
secondary_gp = gp;
arch_spin_unlock(&launch_lock);
}
/*
* Detect available CPUs, populate cpu_possible_mask before smp_init
*
* We don't want to start the secondary CPU yet nor do we have a nice probing
* feature in PMON so we just assume presence of the secondary core.
*/
static void __init yos_smp_setup(void)
{
int i;
init_cpu_possible(cpu_none_mask);
for (i = 0; i < 2; i++) {
set_cpu_possible(i, true);
__cpu_number_map[i] = i;
__cpu_logical_map[i] = i;
}
}
static void __init yos_prepare_cpus(unsigned int max_cpus)
{
/*
* Be paranoid. Enable the IPI only if we're really about to go SMP.
*/
if (num_possible_cpus())
set_c0_status(STATUSF_IP5);
}
struct plat_smp_ops yos_smp_ops = {
.send_ipi_single = yos_send_ipi_single,
.send_ipi_mask = yos_send_ipi_mask,
.init_secondary = yos_init_secondary,
.smp_finish = yos_smp_finish,
.cpus_done = yos_cpus_done,
.boot_secondary = yos_boot_secondary,
.smp_setup = yos_smp_setup,
.prepare_cpus = yos_prepare_cpus,
};
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