/* * File: htirq.c * Purpose: Hypertransport Interrupt Capability * * Copyright (C) 2006 Linux Networx * Copyright (C) Eric Biederman <ebiederman@lnxi.com> */ #include <linux/irq.h> #include <linux/pci.h> #include <linux/spinlock.h> #include <linux/slab.h> #include <linux/gfp.h> #include <linux/htirq.h> /* Global ht irq lock. * * This is needed to serialize access to the data port in hypertransport * irq capability. * * With multiple simultaneous hypertransport irq devices it might pay * to make this more fine grained. But start with simple, stupid, and correct. */ static DEFINE_SPINLOCK(ht_irq_lock); struct ht_irq_cfg { struct pci_dev *dev; /* Update callback used to cope with buggy hardware */ ht_irq_update_t *update; unsigned pos; unsigned idx; struct ht_irq_msg msg; }; void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) { struct ht_irq_cfg *cfg = get_irq_data(irq); unsigned long flags; spin_lock_irqsave(&ht_irq_lock, flags); if (cfg->msg.address_lo != msg->address_lo) { pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx); pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_lo); } if (cfg->msg.address_hi != msg->address_hi) { pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1); pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi); } if (cfg->update) cfg->update(cfg->dev, irq, msg); spin_unlock_irqrestore(&ht_irq_lock, flags); cfg->msg = *msg; } void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg) { struct ht_irq_cfg *cfg = get_irq_data(irq); *msg = cfg->msg; } void mask_ht_irq(unsigned int irq) { struct ht_irq_cfg *cfg; struct ht_irq_msg msg; cfg = get_irq_data(irq); msg = cfg->msg; msg.address_lo |= 1; write_ht_irq_msg(irq, &msg); } void unmask_ht_irq(unsigned int irq) { struct ht_irq_cfg *cfg; struct ht_irq_msg msg; cfg = get_irq_data(irq); msg = cfg->msg; msg.address_lo &= ~1; write_ht_irq_msg(irq, &msg); } /** * __ht_create_irq - create an irq and attach it to a device. * @dev: The hypertransport device to find the irq capability on. * @idx: Which of the possible irqs to attach to. * @update: Function to be called when changing the htirq message * * The irq number of the new irq or a negative error value is returned. */ int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update) { struct ht_irq_cfg *cfg; unsigned long flags; u32 data; int max_irq; int pos; int irq; pos = pci_find_ht_capability(dev, HT_CAPTYPE_IRQ); if (!pos) return -EINVAL; /* Verify the idx I want to use is in range */ spin_lock_irqsave(&ht_irq_lock, flags); pci_write_config_byte(dev, pos + 2, 1); pci_read_config_dword(dev, pos + 4, &data); spin_unlock_irqrestore(&ht_irq_lock, flags); max_irq = (data >> 16) & 0xff; if ( idx > max_irq) return -EINVAL; cfg = kmalloc(sizeof(*cfg), GFP_KERNEL); if (!cfg) return -ENOMEM; cfg->dev = dev; cfg->update = update; cfg->pos = pos; cfg->idx = 0x10 + (idx * 2); /* Initialize msg to a value that will never match the first write. */ cfg->msg.address_lo = 0xffffffff; cfg->msg.address_hi = 0xffffffff; irq = create_irq(); if (irq <= 0) { kfree(cfg); return -EBUSY; } set_irq_data(irq, cfg); if (arch_setup_ht_irq(irq, dev) < 0) { ht_destroy_irq(irq); return -EBUSY; } return irq; } /** * ht_create_irq - create an irq and attach it to a device. * @dev: The hypertransport device to find the irq capability on. * @idx: Which of the possible irqs to attach to. * * ht_create_irq needs to be called for all hypertransport devices * that generate irqs. * * The irq number of the new irq or a negative error value is returned. */ int ht_create_irq(struct pci_dev *dev, int idx) { return __ht_create_irq(dev, idx, NULL); } /** * ht_destroy_irq - destroy an irq created with ht_create_irq * * This reverses ht_create_irq removing the specified irq from * existence. The irq should be free before this happens. */ void ht_destroy_irq(unsigned int irq) { struct ht_irq_cfg *cfg; cfg = get_irq_data(irq); set_irq_chip(irq, NULL); set_irq_data(irq, NULL); destroy_irq(irq); kfree(cfg); } EXPORT_SYMBOL(__ht_create_irq); EXPORT_SYMBOL(ht_create_irq); EXPORT_SYMBOL(ht_destroy_irq);