1/*
2 * This file manages the translation entries for the IBM Calgary IOMMU.
3 *
4 * Derived from arch/powerpc/platforms/pseries/iommu.c
5 *
6 * Copyright (C) IBM Corporation, 2006
7 *
8 * Author: Jon Mason <jdmason@us.ibm.com>
9 * Author: Muli Ben-Yehuda <muli@il.ibm.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19 * GNU General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
24 */
25
26#include <linux/types.h>
27#include <linux/slab.h>
28#include <linux/mm.h>
29#include <linux/spinlock.h>
30#include <linux/string.h>
31#include <linux/pci.h>
32#include <linux/dma-mapping.h>
33#include <linux/bootmem.h>
34#include <asm/tce.h>
35#include <asm/calgary.h>
36#include <asm/proto.h>
37
38/* flush a tce at 'tceaddr' to main memory */
39static inline void flush_tce(void* tceaddr)
40{
41	/* a single tce can't cross a cache line */
42	if (cpu_has_clflush)
43		asm volatile("clflush (%0)" :: "r" (tceaddr));
44	else
45		asm volatile("wbinvd":::"memory");
46}
47
48void tce_build(struct iommu_table *tbl, unsigned long index,
49	unsigned int npages, unsigned long uaddr, int direction)
50{
51	u64* tp;
52	u64 t;
53	u64 rpn;
54
55	t = (1 << TCE_READ_SHIFT);
56	if (direction != DMA_TO_DEVICE)
57		t |= (1 << TCE_WRITE_SHIFT);
58
59	tp = ((u64*)tbl->it_base) + index;
60
61	while (npages--) {
62		rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
63		t &= ~TCE_RPN_MASK;
64		t |= (rpn << TCE_RPN_SHIFT);
65
66		*tp = cpu_to_be64(t);
67		flush_tce(tp);
68
69		uaddr += PAGE_SIZE;
70		tp++;
71	}
72}
73
74void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
75{
76	u64* tp;
77
78	tp  = ((u64*)tbl->it_base) + index;
79
80	while (npages--) {
81		*tp = cpu_to_be64(0);
82		flush_tce(tp);
83		tp++;
84	}
85}
86
87static inline unsigned int table_size_to_number_of_entries(unsigned char size)
88{
89	/*
90	 * size is the order of the table, 0-7
91	 * smallest table is 8K entries, so shift result by 13 to
92	 * multiply by 8K
93	 */
94	return (1 << size) << 13;
95}
96
97static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
98{
99	unsigned int bitmapsz;
100	unsigned long bmppages;
101	int ret;
102
103	tbl->it_busno = dev->bus->number;
104
105	/* set the tce table size - measured in entries */
106	tbl->it_size = table_size_to_number_of_entries(specified_table_size);
107
108	/*
109	 * number of bytes needed for the bitmap size in number of
110	 * entries; we need one bit per entry
111	 */
112	bitmapsz = tbl->it_size / BITS_PER_BYTE;
113	bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
114	if (!bmppages) {
115		printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
116		ret = -ENOMEM;
117		goto done;
118	}
119
120	tbl->it_map = (unsigned long*)bmppages;
121
122	memset(tbl->it_map, 0, bitmapsz);
123
124	tbl->it_hint = 0;
125
126	spin_lock_init(&tbl->it_lock);
127
128	return 0;
129
130done:
131	return ret;
132}
133
134int build_tce_table(struct pci_dev *dev, void __iomem *bbar)
135{
136	struct iommu_table *tbl;
137	int ret;
138
139	if (dev->sysdata) {
140		printk(KERN_ERR "Calgary: dev %p has sysdata %p\n",
141		       dev, dev->sysdata);
142		BUG();
143	}
144
145	tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
146	if (!tbl) {
147		printk(KERN_ERR "Calgary: error allocating iommu_table\n");
148		ret = -ENOMEM;
149		goto done;
150	}
151
152	ret = tce_table_setparms(dev, tbl);
153	if (ret)
154		goto free_tbl;
155
156	tbl->bbar = bbar;
157
158	/*
159	 * NUMA is already using the bus's sysdata pointer, so we use
160	 * the bus's pci_dev's sysdata instead.
161	 */
162	dev->sysdata = tbl;
163
164	return 0;
165
166free_tbl:
167	kfree(tbl);
168done:
169	return ret;
170}
171
172void* alloc_tce_table(void)
173{
174	unsigned int size;
175
176	size = table_size_to_number_of_entries(specified_table_size);
177	size *= TCE_ENTRY_SIZE;
178
179	return __alloc_bootmem_low(size, size, 0);
180}
181
182void free_tce_table(void *tbl)
183{
184	unsigned int size;
185
186	if (!tbl)
187		return;
188
189	size = table_size_to_number_of_entries(specified_table_size);
190	size *= TCE_ENTRY_SIZE;
191
192	free_bootmem(__pa(tbl), size);
193}
194