diff options
Diffstat (limited to 'arch/mips/mti-malta/malta-smtc.c')
| -rw-r--r-- | arch/mips/mti-malta/malta-smtc.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/mips/mti-malta/malta-smtc.c b/arch/mips/mti-malta/malta-smtc.c new file mode 100644 index 00000000000..5ea705e4945 --- /dev/null +++ b/arch/mips/mti-malta/malta-smtc.c @@ -0,0 +1,154 @@ +/* + * 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(cpumask_t mask, unsigned int action) +{ + unsigned int i; + + for_each_cpu_mask(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) +{ + mipsmt_build_cpu_map(0); +} + +static void __init msmtc_prepare_cpus(unsigned int max_cpus) +{ + mipsmt_prepare_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 + */ + + +void plat_set_irq_affinity(unsigned int irq, cpumask_t affinity) +{ + cpumask_t tmask = affinity; + 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". + */ + + for_each_cpu_mask(cpu, affinity) { + if ((cpu_data[cpu].vpe_id != 0) || !cpu_online(cpu)) + cpu_clear(cpu, tmask); + } + 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); +} +#endif /* CONFIG_MIPS_MT_SMTC_IRQAFF */ |