diff options
Diffstat (limited to 'drivers/pci/htirq.c')
| -rw-r--r-- | drivers/pci/htirq.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/pci/htirq.c b/drivers/pci/htirq.c new file mode 100644 index 00000000..6e373ea5 --- /dev/null +++ b/drivers/pci/htirq.c @@ -0,0 +1,176 @@ +/* + * 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/export.h> +#include <linux/slab.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 = irq_get_handler_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 = irq_get_handler_data(irq); + *msg = cfg->msg; +} + +void mask_ht_irq(struct irq_data *data) +{ + struct ht_irq_cfg *cfg = irq_data_get_irq_handler_data(data); + struct ht_irq_msg msg = cfg->msg; + + msg.address_lo |= 1; + write_ht_irq_msg(data->irq, &msg); +} + +void unmask_ht_irq(struct irq_data *data) +{ + struct ht_irq_cfg *cfg = irq_data_get_irq_handler_data(data); + struct ht_irq_msg msg = cfg->msg; + + msg.address_lo &= ~1; + write_ht_irq_msg(data->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; + int node; + + 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; + + node = dev_to_node(&dev->dev); + irq = create_irq_nr(0, node); + + if (irq <= 0) { + kfree(cfg); + return -EBUSY; + } + irq_set_handler_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 + * @irq: irq to be destroyed + * + * 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 = irq_get_handler_data(irq); + irq_set_chip(irq, NULL); + irq_set_handler_data(irq, NULL); + destroy_irq(irq); + + kfree(cfg); +} + +EXPORT_SYMBOL(__ht_create_irq); +EXPORT_SYMBOL(ht_create_irq); +EXPORT_SYMBOL(ht_destroy_irq); |