x86/PCI: Remove unused HyperTransport interrupt support

There are no in-tree callers of ht_create_irq(), the driver interface for
HyperTransport interrupts, left.  Remove the unused entry point and all the
supporting code.

See 8b955b0d ("[PATCH] Initial generic hypertransport interrupt
support").
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-pci@vger.kernel.org
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Link: https://lkml.kernel.org/r/20171122221337.3877.23362.stgit@bhelgaas-glaptop.roam.corp.google.com

arch/x86/include/asm/hw_irq.h

@@ -99,14 +99,6 @@ struct irq_alloc_info {
 			void		*dmar_data;
 		};
 #endif
-#ifdef	CONFIG_HT_IRQ
-		struct {
-			int		ht_pos;
-			int		ht_idx;
-			struct pci_dev	*ht_dev;
-			void		*ht_update;
-		};
-#endif
 #ifdef	CONFIG_X86_UV
 		struct {
 			int		uv_limit;

arch/x86/include/asm/hypertransport.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_X86_HYPERTRANSPORT_H
-#define _ASM_X86_HYPERTRANSPORT_H
-
-/*
- * Constants for x86 Hypertransport Interrupts.
- */
-
-#define HT_IRQ_LOW_BASE			0xf8000000
-
-#define HT_IRQ_LOW_VECTOR_SHIFT		16
-#define HT_IRQ_LOW_VECTOR_MASK		0x00ff0000
-#define HT_IRQ_LOW_VECTOR(v)						\
-	(((v) << HT_IRQ_LOW_VECTOR_SHIFT) & HT_IRQ_LOW_VECTOR_MASK)
-
-#define HT_IRQ_LOW_DEST_ID_SHIFT	8
-#define HT_IRQ_LOW_DEST_ID_MASK		0x0000ff00
-#define HT_IRQ_LOW_DEST_ID(v)						\
-	(((v) << HT_IRQ_LOW_DEST_ID_SHIFT) & HT_IRQ_LOW_DEST_ID_MASK)
-
-#define HT_IRQ_LOW_DM_PHYSICAL		0x0000000
-#define HT_IRQ_LOW_DM_LOGICAL		0x0000040
-
-#define HT_IRQ_LOW_RQEOI_EDGE		0x0000000
-#define HT_IRQ_LOW_RQEOI_LEVEL		0x0000020
-
-
-#define HT_IRQ_LOW_MT_FIXED		0x0000000
-#define HT_IRQ_LOW_MT_ARBITRATED	0x0000004
-#define HT_IRQ_LOW_MT_SMI		0x0000008
-#define HT_IRQ_LOW_MT_NMI		0x000000c
-#define HT_IRQ_LOW_MT_INIT		0x0000010
-#define HT_IRQ_LOW_MT_STARTUP		0x0000014
-#define HT_IRQ_LOW_MT_EXTINT		0x0000018
-#define HT_IRQ_LOW_MT_LINT1		0x000008c
-#define HT_IRQ_LOW_MT_LINT0		0x0000098
-
-#define HT_IRQ_LOW_IRQ_MASKED		0x0000001
-
-
-#define HT_IRQ_HIGH_DEST_ID_SHIFT	0
-#define HT_IRQ_HIGH_DEST_ID_MASK	0x00ffffff
-#define HT_IRQ_HIGH_DEST_ID(v)						\
-	((((v) >> 8) << HT_IRQ_HIGH_DEST_ID_SHIFT) & HT_IRQ_HIGH_DEST_ID_MASK)
-
-#endif /* _ASM_X86_HYPERTRANSPORT_H */

arch/x86/include/asm/irqdomain.h

@@ -56,10 +56,4 @@ extern void arch_init_msi_domain(struct irq_domain *domain);
 static inline void arch_init_msi_domain(struct irq_domain *domain) { }
 #endif
 
-#ifdef CONFIG_HT_IRQ
-extern void arch_init_htirq_domain(struct irq_domain *domain);
-#else
-static inline void arch_init_htirq_domain(struct irq_domain *domain) { }
-#endif
-
 #endif

arch/x86/kernel/apic/Makefile

@@ -12,7 +12,6 @@ obj-y				+= hw_nmi.o
 
 obj-$(CONFIG_X86_IO_APIC)	+= io_apic.o
 obj-$(CONFIG_PCI_MSI)		+= msi.o
-obj-$(CONFIG_HT_IRQ)		+= htirq.o
 obj-$(CONFIG_SMP)		+= ipi.o
 
 ifeq ($(CONFIG_X86_64),y)

arch/x86/kernel/apic/htirq.c

-/*
- * Support Hypertransport IRQ
- *
- * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
- *	Moved from arch/x86/kernel/apic/io_apic.c.
- * Jiang Liu <jiang.liu@linux.intel.com>
- *	Add support of hierarchical irqdomain
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-#include <linux/mm.h>
-#include <linux/interrupt.h>
-#include <linux/init.h>
-#include <linux/device.h>
-#include <linux/pci.h>
-#include <linux/htirq.h>
-#include <asm/irqdomain.h>
-#include <asm/hw_irq.h>
-#include <asm/apic.h>
-#include <asm/hypertransport.h>
-
-static struct irq_domain *htirq_domain;
-
-/*
- * Hypertransport interrupt support
- */
-static int
-ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
-{
-	struct irq_data *parent = data->parent_data;
-	int ret;
-
-	ret = parent->chip->irq_set_affinity(parent, mask, force);
-	if (ret >= 0) {
-		struct ht_irq_msg msg;
-		struct irq_cfg *cfg = irqd_cfg(data);
-
-		fetch_ht_irq_msg(data->irq, &msg);
-		msg.address_lo &= ~(HT_IRQ_LOW_VECTOR_MASK |
-				    HT_IRQ_LOW_DEST_ID_MASK);
-		msg.address_lo |= HT_IRQ_LOW_VECTOR(cfg->vector) |
-				  HT_IRQ_LOW_DEST_ID(cfg->dest_apicid);
-		msg.address_hi &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
-		msg.address_hi |= HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
-		write_ht_irq_msg(data->irq, &msg);
-	}
-
-	return ret;
-}
-
-static struct irq_chip ht_irq_chip = {
-	.name			= "PCI-HT",
-	.irq_mask		= mask_ht_irq,
-	.irq_unmask		= unmask_ht_irq,
-	.irq_ack		= irq_chip_ack_parent,
-	.irq_set_affinity	= ht_set_affinity,
-	.irq_retrigger		= irq_chip_retrigger_hierarchy,
-	.flags			= IRQCHIP_SKIP_SET_WAKE,
-};
-
-static int htirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
-			      unsigned int nr_irqs, void *arg)
-{
-	struct ht_irq_cfg *ht_cfg;
-	struct irq_alloc_info *info = arg;
-	struct pci_dev *dev;
-	irq_hw_number_t hwirq;
-	int ret;
-
-	if (nr_irqs > 1 || !info)
-		return -EINVAL;
-
-	dev = info->ht_dev;
-	hwirq = (info->ht_idx & 0xFF) |
-		PCI_DEVID(dev->bus->number, dev->devfn) << 8 |
-		(pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 24;
-	if (irq_find_mapping(domain, hwirq) > 0)
-		return -EEXIST;
-
-	ht_cfg = kmalloc(sizeof(*ht_cfg), GFP_KERNEL);
-	if (!ht_cfg)
-		return -ENOMEM;
-
-	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
-	if (ret < 0) {
-		kfree(ht_cfg);
-		return ret;
-	}
-
-	/* Initialize msg to a value that will never match the first write. */
-	ht_cfg->msg.address_lo = 0xffffffff;
-	ht_cfg->msg.address_hi = 0xffffffff;
-	ht_cfg->dev = info->ht_dev;
-	ht_cfg->update = info->ht_update;
-	ht_cfg->pos = info->ht_pos;
-	ht_cfg->idx = 0x10 + (info->ht_idx * 2);
-	irq_domain_set_info(domain, virq, hwirq, &ht_irq_chip, ht_cfg,
-			    handle_edge_irq, ht_cfg, "edge");
-
-	return 0;
-}
-
-static void htirq_domain_free(struct irq_domain *domain, unsigned int virq,
-			      unsigned int nr_irqs)
-{
-	struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
-
-	BUG_ON(nr_irqs != 1);
-	kfree(irq_data->chip_data);
-	irq_domain_free_irqs_top(domain, virq, nr_irqs);
-}
-
-static int htirq_domain_activate(struct irq_domain *domain,
-				 struct irq_data *irq_data, bool early)
-{
-	struct ht_irq_msg msg;
-	struct irq_cfg *cfg = irqd_cfg(irq_data);
-
-	msg.address_hi = HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
-	msg.address_lo =
-		HT_IRQ_LOW_BASE |
-		HT_IRQ_LOW_DEST_ID(cfg->dest_apicid) |
-		HT_IRQ_LOW_VECTOR(cfg->vector) |
-		((apic->irq_dest_mode == 0) ?
-			HT_IRQ_LOW_DM_PHYSICAL :
-			HT_IRQ_LOW_DM_LOGICAL) |
-		HT_IRQ_LOW_RQEOI_EDGE |
-		((apic->irq_delivery_mode != dest_LowestPrio) ?
-			HT_IRQ_LOW_MT_FIXED :
-			HT_IRQ_LOW_MT_ARBITRATED) |
-		HT_IRQ_LOW_IRQ_MASKED;
-	write_ht_irq_msg(irq_data->irq, &msg);
-	return 0;
-}
-
-static void htirq_domain_deactivate(struct irq_domain *domain,
-				    struct irq_data *irq_data)
-{
-	struct ht_irq_msg msg;
-
-	memset(&msg, 0, sizeof(msg));
-	write_ht_irq_msg(irq_data->irq, &msg);
-}
-
-static const struct irq_domain_ops htirq_domain_ops = {
-	.alloc		= htirq_domain_alloc,
-	.free		= htirq_domain_free,
-	.activate	= htirq_domain_activate,
-	.deactivate	= htirq_domain_deactivate,
-};
-
-void __init arch_init_htirq_domain(struct irq_domain *parent)
-{
-	struct fwnode_handle *fn;
-
-	if (disable_apic)
-		return;
-
-	fn = irq_domain_alloc_named_fwnode("PCI-HT");
-	if (!fn)
-		goto warn;
-
-	htirq_domain = irq_domain_create_tree(fn, &htirq_domain_ops, NULL);
-	irq_domain_free_fwnode(fn);
-	if (!htirq_domain)
-		goto warn;
-
-	htirq_domain->parent = parent;
-	return;
-
-warn:
-	pr_warn("Failed to initialize irqdomain for HTIRQ.\n");
-}
-
-int arch_setup_ht_irq(int idx, int pos, struct pci_dev *dev,
-		      ht_irq_update_t *update)
-{
-	struct irq_alloc_info info;
-
-	if (!htirq_domain)
-		return -ENOSYS;
-
-	init_irq_alloc_info(&info, NULL);
-	info.ht_idx = idx;
-	info.ht_pos = pos;
-	info.ht_dev = dev;
-	info.ht_update = update;
-
-	return irq_domain_alloc_irqs(htirq_domain, 1, dev_to_node(&dev->dev),
-				     &info);
-}
-
-void arch_teardown_ht_irq(unsigned int irq)
-{
-	irq_domain_free_irqs(irq, 1);
-}

arch/x86/kernel/apic/vector.c

 /*
- * Local APIC related interfaces to support IOAPIC, MSI, HT_IRQ etc.
+ * Local APIC related interfaces to support IOAPIC, MSI, etc.
  *
  * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
  *	Moved from arch/x86/kernel/apic/io_apic.c.
@@ -601,7 +601,7 @@ int __init arch_probe_nr_irqs(void)
 		nr_irqs = NR_VECTORS * nr_cpu_ids;
 
 	nr = (gsi_top + nr_legacy_irqs()) + 8 * nr_cpu_ids;
-#if defined(CONFIG_PCI_MSI) || defined(CONFIG_HT_IRQ)
+#if defined(CONFIG_PCI_MSI)
 	/*
 	 * for MSI and HT dyn irq
 	 */
@@ -663,7 +663,6 @@ int __init arch_early_irq_init(void)
 	irq_set_default_host(x86_vector_domain);
 
 	arch_init_msi_domain(x86_vector_domain);
-	arch_init_htirq_domain(x86_vector_domain);
 
 	BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
 

drivers/pci/Kconfig

@@ -71,15 +71,6 @@ config XEN_PCIDEV_FRONTEND
           The PCI device frontend driver allows the kernel to import arbitrary
           PCI devices from a PCI backend to support PCI driver domains.
 
-config HT_IRQ
-	bool "Interrupts on hypertransport devices"
-	default y
-	depends on PCI && X86_LOCAL_APIC
-	help
-	   This allows native hypertransport devices to use interrupts.
-
-	   If unsure say Y.
-
 config PCI_ATS
 	bool
 

drivers/pci/Makefile

@@ -24,9 +24,6 @@ endif
 # Build the PCI MSI interrupt support
 obj-$(CONFIG_PCI_MSI) += msi.o
 
-# Build the Hypertransport interrupt support
-obj-$(CONFIG_HT_IRQ) += htirq.o
-
 obj-$(CONFIG_PCI_ATS) += ats.o
 obj-$(CONFIG_PCI_IOV) += iov.o
 

drivers/pci/htirq.c

-// SPDX-License-Identifier: GPL-2.0
-/*
- * 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);
-
-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)
-{
-	int max_irq, pos, irq;
-	unsigned long flags;
-	u32 data;
-
-	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;
-
-	irq = arch_setup_ht_irq(idx, pos, dev, update);
-	if (irq > 0)
-		dev_dbg(&dev->dev, "irq %d for HT\n", irq);
-
-	return irq;
-}
-EXPORT_SYMBOL(__ht_create_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);
-}
-EXPORT_SYMBOL(ht_create_irq);
-
-/**
- * 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)
-{
-	arch_teardown_ht_irq(irq);
-}
-EXPORT_SYMBOL(ht_destroy_irq);

include/linux/htirq.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef LINUX_HTIRQ_H
-#define LINUX_HTIRQ_H
-
-struct pci_dev;
-struct irq_data;
-
-struct ht_irq_msg {
-	u32	address_lo;	/* low 32 bits of the ht irq message */
-	u32	address_hi;	/* high 32 bits of the it irq message */
-};
-
-typedef void (ht_irq_update_t)(struct pci_dev *dev, int irq,
-			       struct ht_irq_msg *msg);
-
-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;
-};
-
-/* Helper functions.. */
-void fetch_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg);
-void write_ht_irq_msg(unsigned int irq, struct ht_irq_msg *msg);
-void mask_ht_irq(struct irq_data *data);
-void unmask_ht_irq(struct irq_data *data);
-
-/* The arch hook for getting things started */
-int arch_setup_ht_irq(int idx, int pos, struct pci_dev *dev,
-		      ht_irq_update_t *update);
-void arch_teardown_ht_irq(unsigned int irq);
-
-/* For drivers of buggy hardware */
-int __ht_create_irq(struct pci_dev *dev, int idx, ht_irq_update_t *update);
-
-#endif /* LINUX_HTIRQ_H */

include/linux/pci.h

@@ -1484,12 +1484,6 @@ static inline void pcie_set_ecrc_checking(struct pci_dev *dev) { }
 static inline void pcie_ecrc_get_policy(char *str) { }
 #endif
 
-#ifdef CONFIG_HT_IRQ
-/* The functions a driver should call */
-int  ht_create_irq(struct pci_dev *dev, int idx);
-void ht_destroy_irq(unsigned int irq);
-#endif /* CONFIG_HT_IRQ */
-
 #ifdef CONFIG_PCI_ATS
 /* Address Translation Service */
 void pci_ats_init(struct pci_dev *dev);