[RFC 06/10] powerpc: MPIC sys_device & suspend/resume
From: Johannes Berg <johannes@sipsolutions.net>
Date: 2007-02-05 18:30:33
Also in:
linux-pm
This adds mpic to the system devices and implements suspend and resume for them. This is necessary to get interrupts for modules back to where they were before a suspend to disk. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- The first hunk is just a tiny whitespace cleanup. Without this patch, i2sbus (built as a module) for example doesn't work properly across a suspend-to-disk/resume cycle, with this patch it works fine. I'm not entirely sure if there should be some wait logic after I restore the MPIC registers, it works as-is for me.
--- mb-wireless.orig/arch/powerpc/sysdev/mpic.c 2007-02-05 14:24:05.734526864 +0100
+++ mb-wireless/arch/powerpc/sysdev/mpic.c 2007-02-05 14:24:39.464526864 +0100@@ -1123,7 +1123,7 @@ void __init mpic_init(struct mpic *mpic) /* Do the HT PIC fixups on U3 broken mpic */ DBG("MPIC flags: %x\n", mpic->flags); if ((mpic->flags & MPIC_BROKEN_U3) && (mpic->flags & MPIC_PRIMARY)) - mpic_scan_ht_pics(mpic); + mpic_scan_ht_pics(mpic); for (i = 0; i < mpic->num_sources; i++) { /* start with vector = source number, and masked */
@@ -1147,6 +1147,12 @@ void __init mpic_init(struct mpic *mpic) /* Set current processor priority to 0 */ mpic_cpu_write(MPIC_INFO(CPU_CURRENT_TASK_PRI), 0); + +#ifdef CONFIG_PM + /* allocate memory to save mpic state */ + mpic->save_data = alloc_bootmem(mpic->num_sources * sizeof(struct mpic_irq_save)); + BUG_ON(mpic->save_data == NULL); +#endif } void __init mpic_set_clk_ratio(struct mpic *mpic, u32 clock_ratio)
@@ -1376,3 +1382,61 @@ void smp_mpic_message_pass(int target, i } } #endif /* CONFIG_SMP */ + +#ifdef CONFIG_PM +static int mpic_suspend(struct sys_device *dev, pm_message_t state) +{ + struct mpic *mpic = container_of(dev, struct mpic, sysdev); + int i; + + for (i = 0; i < mpic->num_sources; i++) { + mpic->save_data[i].vecprio = + mpic_irq_read(i, MPIC_INFO(IRQ_VECTOR_PRI)); + mpic->save_data[i].dest = + mpic_irq_read(i, MPIC_INFO(IRQ_DESTINATION)); + } + + return 0; +} + +static int mpic_resume(struct sys_device *dev) +{ + struct mpic *mpic = container_of(dev, struct mpic, sysdev); + int i; + + for (i = 0; i < mpic->num_sources; i++) { + mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI), + mpic->save_data[i].vecprio); + mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION), + mpic->save_data[i].dest); + } + + return 0; +} +#endif + +static struct sysdev_class mpic_sysclass = { +#ifdef CONFIG_PM + .resume = mpic_resume, + .suspend = mpic_suspend, +#endif + set_kset_name("mpic"), +}; + +static int mpic_init_sys(void) +{ + struct mpic *mpic = mpics; + int error, id = 0; + + error = sysdev_class_register(&mpic_sysclass); + + while (mpic && !error) { + mpic->sysdev.cls = &mpic_sysclass; + mpic->sysdev.id = id++; + error = sysdev_register(&mpic->sysdev); + mpic = mpic->next; + } + return error; +} + +device_initcall(mpic_init_sys); --- mb-wireless.orig/include/asm-powerpc/mpic.h 2007-02-05 14:24:05.784526864 +0100 +++ mb-wireless/include/asm-powerpc/mpic.h 2007-02-05 14:24:39.464526864 +0100
@@ -3,6 +3,7 @@ #ifdef __KERNEL__ #include <linux/irq.h> +#include <linux/sysdev.h> #include <asm/dcr.h> /*
@@ -243,6 +244,11 @@ struct mpic_reg_bank { #endif /* CONFIG_PPC_DCR */ }; +struct mpic_irq_save { + u32 vecprio, + dest; +}; + /* The instance data of a given MPIC */ struct mpic {
@@ -302,6 +308,12 @@ struct mpic /* link */ struct mpic *next; + + struct sys_device sysdev; + +#ifdef CONFIG_PM + struct mpic_irq_save *save_data; +#endif }; /* --