/*
* Malta Platform-specific hooks for SMP operation
*/
#include <linux/irq.h>
#include <linux/init.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/smtc.h>
#include <asm/smtc_ipi.h>
/* VPE/SMP Prototype implements platform interfaces directly */
/*
* Cause the specified action to be performed on a targeted "CPU"
*/
static void msmtc_send_ipi_single(int cpu, unsigned int action)
{
/* "CPU" may be TC of same VPE, VPE of same CPU, or different CPU */
smtc_send_ipi(cpu, LINUX_SMP_IPI, action);
}
static void msmtc_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
unsigned int i;
for_each_cpu(i, mask)
msmtc_send_ipi_single(i, action);
}
/*
* Post-config but pre-boot cleanup entry point
*/
static void __cpuinit msmtc_init_secondary(void)
{
void smtc_init_secondary(void);
int myvpe;
/* Don't enable Malta I/O interrupts (IP2) for secondary VPEs */
myvpe = read_c0_tcbind() & TCBIND_CURVPE;
if (myvpe != 0) {
/* Ideally, this should be done only once per VPE, but... */
clear_c0_status(ST0_IM);
set_c0_status((0x100 << cp0_compare_irq)
| (0x100 << MIPS_CPU_IPI_IRQ));
if (cp0_perfcount_irq >= 0)
set_c0_status(0x100 << cp0_perfcount_irq);
}
smtc_init_secondary();
}
/*
* Platform "CPU" startup hook
*/
static void __cpuinit msmtc_boot_secondary(int cpu, struct task_struct *idle)
{
smtc_boot_secondary(cpu, idle);
}
/*
* SMP initialization finalization entry point
*/
static void __cpuinit msmtc_smp_finish(void)
{
smtc_smp_finish();
}
/*
* Hook for after all CPUs are online
*/
static void msmtc_cpus_done(void)
{
}
/*
* Platform SMP pre-initialization
*
* As noted above, we can assume a single CPU for now
* but it may be multithreaded.
*/
static void __init msmtc_smp_setup(void)
{
/*
* we won't get the definitive value until
* we've run smtc_prepare_cpus later, but
* we would appear to need an upper bound now.
*/
smp_num_siblings = smtc_build_cpu_map(0);
}
static void __init msmtc_prepare_cpus(unsigned int max_cpus)
{
smtc_prepare_cpus(max_cpus);
}
struct plat_smp_ops msmtc_smp_ops = {
.send_ipi_single = msmtc_send_ipi_single,
.send_ipi_mask = msmtc_send_ipi_mask,
.init_secondary = msmtc_init_secondary,
.smp_finish = msmtc_smp_finish,
.cpus_done = msmtc_cpus_done,
.boot_secondary = msmtc_boot_secondary,
.smp_setup = msmtc_smp_setup,
.prepare_cpus = msmtc_prepare_cpus,
};
#ifdef CONFIG_MIPS_MT_SMTC_IRQAFF
/*
* IRQ affinity hook
*/
int plat_set_irq_affinity(unsigned int irq, const struct cpumask *affinity)
{
cpumask_t tmask;
int cpu = 0;
void smtc_set_irq_affinity(unsigned int irq, cpumask_t aff);
/*
* On the legacy Malta development board, all I/O interrupts
* are routed through the 8259 and combined in a single signal
* to the CPU daughterboard, and on the CoreFPGA2/3 34K models,
* that signal is brought to IP2 of both VPEs. To avoid racing
* concurrent interrupt service events, IP2 is enabled only on
* one VPE, by convention VPE0. So long as no bits are ever
* cleared in the affinity mask, there will never be any
* interrupt forwarding. But as soon as a program or operator
* sets affinity for one of the related IRQs, we need to make
* sure that we don't ever try to forward across the VPE boundry,
* at least not until we engineer a system where the interrupt
* _ack() or _end() function can somehow know that it corresponds
* to an interrupt taken on another VPE, and perform the appropriate
* restoration of Status.IM state using MFTR/MTTR instead of the
* normal local behavior. We also ensure that no attempt will
* be made to forward to an offline "CPU".
*/
cpumask_copy(&tmask, affinity);
for_each_cpu(cpu, affinity) {
if ((cpu_data[cpu].vpe_id != 0) || !cpu_online(cpu))
cpu_clear(cpu, tmask);
}
cpumask_copy(irq_desc[irq].affinity, &tmask);
if (cpus_empty(tmask))
/*
* We could restore a default mask here, but the
* runtime code can anyway deal with the null set
*/
printk(KERN_WARNING
"IRQ affinity leaves no legal CPU for IRQ %d\n", irq);
/* Do any generic SMTC IRQ affinity setup */
smtc_set_irq_affinity(irq, tmask);
return 0;
}
#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */
