diff options
| author | Kevin D. Kissell <kevink@mips.com> | 2007-08-03 19:38:03 +0200 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2007-10-11 23:45:57 +0100 |
| commit | f571eff0a24ed97a919f2b61bb4afdeab4b43002 (patch) | |
| tree | e9d6c597fafca02720f000cf795a37f2d163f10f /arch/mips/mips-boards/malta | |
| parent | bbf25010f1a6b761914430f5fca081ec8c7accd1 (diff) | |
[MIPS] IRQ Affinity Support for SMTC on Malta Platform
Signed-off-by: Kevin D. Kissell <kevink@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mips-boards/malta')
| -rw-r--r-- | arch/mips/mips-boards/malta/malta_smtc.c | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/mips/mips-boards/malta/malta_smtc.c b/arch/mips/mips-boards/malta/malta_smtc.c index ae05d058cb3..5c980f4a48f 100644 --- a/arch/mips/mips-boards/malta/malta_smtc.c +++ b/arch/mips/mips-boards/malta/malta_smtc.c @@ -88,3 +88,53 @@ void __cpuinit prom_smp_finish(void) void prom_cpus_done(void) { } + +#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 */ |