136 lines
3.6 KiB
C
136 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* File: htirq.c
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* Purpose: Hypertransport Interrupt Capability
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*
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* Copyright (C) 2006 Linux Networx
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* Copyright (C) Eric Biederman <ebiederman@lnxi.com>
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*/
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#include <linux/irq.h>
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#include <linux/pci.h>
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#include <linux/spinlock.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/htirq.h>
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/* Global ht irq lock.
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*
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* This is needed to serialize access to the data port in hypertransport
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* irq capability.
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*
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* With multiple simultaneous hypertransport irq devices it might pay
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* to make this more fine grained. But start with simple, stupid, and correct.
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*/
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static DEFINE_SPINLOCK(ht_irq_lock);
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void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
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{
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struct ht_irq_cfg *cfg = irq_get_handler_data(irq);
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unsigned long flags;
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spin_lock_irqsave(&ht_irq_lock, flags);
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if (cfg->msg.address_lo != msg->address_lo) {
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pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx);
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pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_lo);
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}
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if (cfg->msg.address_hi != msg->address_hi) {
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pci_write_config_byte(cfg->dev, cfg->pos + 2, cfg->idx + 1);
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pci_write_config_dword(cfg->dev, cfg->pos + 4, msg->address_hi);
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}
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if (cfg->update)
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cfg->update(cfg->dev, irq, msg);
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spin_unlock_irqrestore(&ht_irq_lock, flags);
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cfg->msg = *msg;
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}
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void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg)
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{
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struct ht_irq_cfg *cfg = irq_get_handler_data(irq);
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*msg = cfg->msg;
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}
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void mask_ht_irq(struct irq_data *data)
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{
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struct ht_irq_cfg *cfg = irq_data_get_irq_handler_data(data);
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struct ht_irq_msg msg = cfg->msg;
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msg.address_lo |= 1;
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write_ht_irq_msg(data->irq, &msg);
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}
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void unmask_ht_irq(struct irq_data *data)
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{
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struct ht_irq_cfg *cfg = irq_data_get_irq_handler_data(data);
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struct ht_irq_msg msg = cfg->msg;
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msg.address_lo &= ~1;
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write_ht_irq_msg(data->irq, &msg);
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}
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/**
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* __ht_create_irq - create an irq and attach it to a device.
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* @dev: The hypertransport device to find the irq capability on.
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* @idx: Which of the possible irqs to attach to.
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* @update: Function to be called when changing the htirq message
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*
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* The irq number of the new irq or a negative error value is returned.
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*/
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int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update)
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{
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int max_irq, pos, irq;
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unsigned long flags;
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u32 data;
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pos = pci_find_ht_capability(dev, HT_CAPTYPE_IRQ);
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if (!pos)
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return -EINVAL;
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/* Verify the idx I want to use is in range */
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spin_lock_irqsave(&ht_irq_lock, flags);
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pci_write_config_byte(dev, pos + 2, 1);
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pci_read_config_dword(dev, pos + 4, &data);
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spin_unlock_irqrestore(&ht_irq_lock, flags);
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max_irq = (data >> 16) & 0xff;
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if (idx > max_irq)
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return -EINVAL;
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irq = arch_setup_ht_irq(idx, pos, dev, update);
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if (irq > 0)
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dev_dbg(&dev->dev, "irq %d for HT\n", irq);
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return irq;
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}
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EXPORT_SYMBOL(__ht_create_irq);
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/**
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* ht_create_irq - create an irq and attach it to a device.
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* @dev: The hypertransport device to find the irq capability on.
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* @idx: Which of the possible irqs to attach to.
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*
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* ht_create_irq needs to be called for all hypertransport devices
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* that generate irqs.
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*
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* The irq number of the new irq or a negative error value is returned.
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*/
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int ht_create_irq(struct pci_dev *dev, int idx)
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{
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return __ht_create_irq(dev, idx, NULL);
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}
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EXPORT_SYMBOL(ht_create_irq);
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/**
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* ht_destroy_irq - destroy an irq created with ht_create_irq
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* @irq: irq to be destroyed
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*
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* This reverses ht_create_irq removing the specified irq from
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* existence. The irq should be free before this happens.
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*/
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void ht_destroy_irq(unsigned int irq)
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{
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arch_teardown_ht_irq(irq);
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}
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EXPORT_SYMBOL(ht_destroy_irq);
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