x86: Remove the calgary IOMMU driver

The calgary IOMMU was only used on high-end IBM systems in the early
x86_64 age and has no known users left.  Remove it to avoid having to
touch it for pending changes to the DMA API.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191113071836.21041-2-hch@lst.de

MAINTAINERS

@@ -3629,16 +3629,6 @@ L:	cake@lists.bufferbloat.net (moderated for non-subscribers)
 S:	Maintained
 F:	net/sched/sch_cake.c
 
-CALGARY x86-64 IOMMU
-M:	Muli Ben-Yehuda <mulix@mulix.org>
-M:	Jon Mason <jdmason@kudzu.us>
-L:	iommu@lists.linux-foundation.org
-S:	Maintained
-F:	arch/x86/kernel/pci-calgary_64.c
-F:	arch/x86/kernel/tce_64.c
-F:	arch/x86/include/asm/calgary.h
-F:	arch/x86/include/asm/tce.h
-
 CAN NETWORK DRIVERS
 M:	Wolfgang Grandegger <wg@grandegger.com>
 M:	Marc Kleine-Budde <mkl@pengutronix.de>

arch/x86/Kconfig

@@ -932,36 +932,6 @@ config GART_IOMMU
 
 	  If unsure, say Y.
 
-config CALGARY_IOMMU
-	bool "IBM Calgary IOMMU support"
-	select IOMMU_HELPER
-	select SWIOTLB
-	depends on X86_64 && PCI
-	---help---
-	  Support for hardware IOMMUs in IBM's xSeries x366 and x460
-	  systems. Needed to run systems with more than 3GB of memory
-	  properly with 32-bit PCI devices that do not support DAC
-	  (Double Address Cycle). Calgary also supports bus level
-	  isolation, where all DMAs pass through the IOMMU.  This
-	  prevents them from going anywhere except their intended
-	  destination. This catches hard-to-find kernel bugs and
-	  mis-behaving drivers and devices that do not use the DMA-API
-	  properly to set up their DMA buffers.  The IOMMU can be
-	  turned off at boot time with the iommu=off parameter.
-	  Normally the kernel will make the right choice by itself.
-	  If unsure, say Y.
-
-config CALGARY_IOMMU_ENABLED_BY_DEFAULT
-	def_bool y
-	prompt "Should Calgary be enabled by default?"
-	depends on CALGARY_IOMMU
-	---help---
-	  Should Calgary be enabled by default? if you choose 'y', Calgary
-	  will be used (if it exists). If you choose 'n', Calgary will not be
-	  used even if it exists. If you choose 'n' and would like to use
-	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
-	  If unsure, say Y.
-
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL

arch/x86/configs/x86_64_defconfig

@@ -25,7 +25,6 @@ CONFIG_MODULES=y
 CONFIG_MODULE_UNLOAD=y
 CONFIG_MODULE_FORCE_UNLOAD=y
 CONFIG_SMP=y
-CONFIG_CALGARY_IOMMU=y
 CONFIG_NR_CPUS=64
 CONFIG_SCHED_SMT=y
 CONFIG_PREEMPT_VOLUNTARY=y

arch/x86/include/asm/calgary.h

-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Derived from include/asm-powerpc/iommu.h
- *
- * Copyright IBM Corporation, 2006-2007
- *
- * Author: Jon Mason <jdmason@us.ibm.com>
- * Author: Muli Ben-Yehuda <muli@il.ibm.com>
- */
-
-#ifndef _ASM_X86_CALGARY_H
-#define _ASM_X86_CALGARY_H
-
-#include <linux/spinlock.h>
-#include <linux/device.h>
-#include <linux/dma-mapping.h>
-#include <linux/timer.h>
-#include <asm/types.h>
-
-struct iommu_table {
-	const struct cal_chipset_ops *chip_ops; /* chipset specific funcs */
-	unsigned long  it_base;      /* mapped address of tce table */
-	unsigned long  it_hint;      /* Hint for next alloc */
-	unsigned long *it_map;       /* A simple allocation bitmap for now */
-	void __iomem  *bbar;         /* Bridge BAR */
-	u64	       tar_val;      /* Table Address Register */
-	struct timer_list watchdog_timer;
-	spinlock_t     it_lock;      /* Protects it_map */
-	unsigned int   it_size;      /* Size of iommu table in entries */
-	unsigned char  it_busno;     /* Bus number this table belongs to */
-};
-
-struct cal_chipset_ops {
-	void (*handle_quirks)(struct iommu_table *tbl, struct pci_dev *dev);
-	void (*tce_cache_blast)(struct iommu_table *tbl);
-	void (*dump_error_regs)(struct iommu_table *tbl);
-};
-
-#define TCE_TABLE_SIZE_UNSPECIFIED	~0
-#define TCE_TABLE_SIZE_64K		0
-#define TCE_TABLE_SIZE_128K		1
-#define TCE_TABLE_SIZE_256K		2
-#define TCE_TABLE_SIZE_512K		3
-#define TCE_TABLE_SIZE_1M		4
-#define TCE_TABLE_SIZE_2M		5
-#define TCE_TABLE_SIZE_4M		6
-#define TCE_TABLE_SIZE_8M		7
-
-extern int use_calgary;
-
-#ifdef CONFIG_CALGARY_IOMMU
-extern int detect_calgary(void);
-#else
-static inline int detect_calgary(void) { return -ENODEV; }
-#endif
-
-#endif /* _ASM_X86_CALGARY_H */

arch/x86/include/asm/pci_64.h

@@ -4,20 +4,6 @@
 
 #ifdef __KERNEL__
 
-#ifdef CONFIG_CALGARY_IOMMU
-static inline void *pci_iommu(struct pci_bus *bus)
-{
-	struct pci_sysdata *sd = bus->sysdata;
-	return sd->iommu;
-}
-
-static inline void set_pci_iommu(struct pci_bus *bus, void *val)
-{
-	struct pci_sysdata *sd = bus->sysdata;
-	sd->iommu = val;
-}
-#endif /* CONFIG_CALGARY_IOMMU */
-
 extern int (*pci_config_read)(int seg, int bus, int dev, int fn,
 			      int reg, int len, u32 *value);
 extern int (*pci_config_write)(int seg, int bus, int dev, int fn,

arch/x86/include/asm/tce.h

-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * This file is derived from asm-powerpc/tce.h.
- *
- * Copyright (C) IBM Corporation, 2006
- *
- * Author: Muli Ben-Yehuda <muli@il.ibm.com>
- * Author: Jon Mason <jdmason@us.ibm.com>
- */
-
-#ifndef _ASM_X86_TCE_H
-#define _ASM_X86_TCE_H
-
-extern unsigned int specified_table_size;
-struct iommu_table;
-
-#define TCE_ENTRY_SIZE   8   /* in bytes */
-
-#define TCE_READ_SHIFT   0
-#define TCE_WRITE_SHIFT  1
-#define TCE_HUBID_SHIFT  2   /* unused */
-#define TCE_RSVD_SHIFT   8   /* unused */
-#define TCE_RPN_SHIFT    12
-#define TCE_UNUSED_SHIFT 48  /* unused */
-
-#define TCE_RPN_MASK     0x0000fffffffff000ULL
-
-extern void tce_build(struct iommu_table *tbl, unsigned long index,
-		      unsigned int npages, unsigned long uaddr, int direction);
-extern void tce_free(struct iommu_table *tbl, long index, unsigned int npages);
-extern void * __init alloc_tce_table(void);
-extern void __init free_tce_table(void *tbl);
-extern int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar);
-
-#endif /* _ASM_X86_TCE_H */

arch/x86/kernel/Makefile

@@ -146,7 +146,6 @@ ifeq ($(CONFIG_X86_64),y)
 	obj-$(CONFIG_AUDIT)		+= audit_64.o
 
 	obj-$(CONFIG_GART_IOMMU)	+= amd_gart_64.o aperture_64.o
-	obj-$(CONFIG_CALGARY_IOMMU)	+= pci-calgary_64.o tce_64.o
 
 	obj-$(CONFIG_MMCONF_FAM10H)	+= mmconf-fam10h_64.o
 	obj-y				+= vsmp_64.o

arch/x86/kernel/pci-dma.c

@@ -12,7 +12,6 @@
 #include <asm/dma.h>
 #include <asm/iommu.h>
 #include <asm/gart.h>
-#include <asm/calgary.h>
 #include <asm/x86_init.h>
 #include <asm/iommu_table.h>
 
@@ -112,11 +111,6 @@ static __init int iommu_setup(char *p)
 
 		gart_parse_options(p);
 
-#ifdef CONFIG_CALGARY_IOMMU
-		if (!strncmp(p, "calgary", 7))
-			use_calgary = 1;
-#endif /* CONFIG_CALGARY_IOMMU */
-
 		p += strcspn(p, ",");
 		if (*p == ',')
 			++p;

arch/x86/kernel/tce_64.c

-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * This file manages the translation entries for the IBM Calgary IOMMU.
- *
- * Derived from arch/powerpc/platforms/pseries/iommu.c
- *
- * Copyright (C) IBM Corporation, 2006
- *
- * Author: Jon Mason <jdmason@us.ibm.com>
- * Author: Muli Ben-Yehuda <muli@il.ibm.com>
- */
-
-#include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/mm.h>
-#include <linux/spinlock.h>
-#include <linux/string.h>
-#include <linux/pci.h>
-#include <linux/dma-mapping.h>
-#include <linux/memblock.h>
-#include <asm/tce.h>
-#include <asm/calgary.h>
-#include <asm/proto.h>
-#include <asm/cacheflush.h>
-
-/* flush a tce at 'tceaddr' to main memory */
-static inline void flush_tce(void* tceaddr)
-{
-	/* a single tce can't cross a cache line */
-	if (boot_cpu_has(X86_FEATURE_CLFLUSH))
-		clflush(tceaddr);
-	else
-		wbinvd();
-}
-
-void tce_build(struct iommu_table *tbl, unsigned long index,
-	unsigned int npages, unsigned long uaddr, int direction)
-{
-	u64* tp;
-	u64 t;
-	u64 rpn;
-
-	t = (1 << TCE_READ_SHIFT);
-	if (direction != DMA_TO_DEVICE)
-		t |= (1 << TCE_WRITE_SHIFT);
-
-	tp = ((u64*)tbl->it_base) + index;
-
-	while (npages--) {
-		rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
-		t &= ~TCE_RPN_MASK;
-		t |= (rpn << TCE_RPN_SHIFT);
-
-		*tp = cpu_to_be64(t);
-		flush_tce(tp);
-
-		uaddr += PAGE_SIZE;
-		tp++;
-	}
-}
-
-void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
-{
-	u64* tp;
-
-	tp  = ((u64*)tbl->it_base) + index;
-
-	while (npages--) {
-		*tp = cpu_to_be64(0);
-		flush_tce(tp);
-		tp++;
-	}
-}
-
-static inline unsigned int table_size_to_number_of_entries(unsigned char size)
-{
-	/*
-	 * size is the order of the table, 0-7
-	 * smallest table is 8K entries, so shift result by 13 to
-	 * multiply by 8K
-	 */
-	return (1 << size) << 13;
-}
-
-static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
-{
-	unsigned int bitmapsz;
-	unsigned long bmppages;
-	int ret;
-
-	tbl->it_busno = dev->bus->number;
-
-	/* set the tce table size - measured in entries */
-	tbl->it_size = table_size_to_number_of_entries(specified_table_size);
-
-	/*
-	 * number of bytes needed for the bitmap size in number of
-	 * entries; we need one bit per entry
-	 */
-	bitmapsz = tbl->it_size / BITS_PER_BYTE;
-	bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
-	if (!bmppages) {
-		printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
-		ret = -ENOMEM;
-		goto done;
-	}
-
-	tbl->it_map = (unsigned long*)bmppages;
-
-	memset(tbl->it_map, 0, bitmapsz);
-
-	tbl->it_hint = 0;
-
-	spin_lock_init(&tbl->it_lock);
-
-	return 0;
-
-done:
-	return ret;
-}
-
-int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
-{
-	struct iommu_table *tbl;
-	int ret;
-
-	if (pci_iommu(dev->bus)) {
-		printk(KERN_ERR "Calgary: dev %p has sysdata->iommu %p\n",
-		       dev, pci_iommu(dev->bus));
-		BUG();
-	}
-
-	tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
-	if (!tbl) {
-		printk(KERN_ERR "Calgary: error allocating iommu_table\n");
-		ret = -ENOMEM;
-		goto done;
-	}
-
-	ret = tce_table_setparms(dev, tbl);
-	if (ret)
-		goto free_tbl;
-
-	tbl->bbar = bbar;
-
-	set_pci_iommu(dev->bus, tbl);
-
-	return 0;
-
-free_tbl:
-	kfree(tbl);
-done:
-	return ret;
-}
-
-void * __init alloc_tce_table(void)
-{
-	unsigned int size;
-
-	size = table_size_to_number_of_entries(specified_table_size);
-	size *= TCE_ENTRY_SIZE;
-
-	return memblock_alloc_low(size, size);
-}
-
-void __init free_tce_table(void *tbl)
-{
-	unsigned int size;
-
-	if (!tbl)
-		return;
-
-	size = table_size_to_number_of_entries(specified_table_size);
-	size *= TCE_ENTRY_SIZE;
-
-	memblock_free(__pa(tbl), size);
-}