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#include <asm/cacheflush.h>
38
39/* flush a tce at 'tceaddr' to main memory */
40static inline void flush_tce(void* tceaddr)
41{
42	/* a single tce can't cross a cache line */
43	if (cpu_has_clflush)
44		clflush(tceaddr);
45	else
46		wbinvd();
47}
48
49void tce_build(struct iommu_table *tbl, unsigned long index,
50	unsigned int npages, unsigned long uaddr, int direction)
51{
52	u64* tp;
53	u64 t;
54	u64 rpn;
55
56	t = (1 << TCE_READ_SHIFT);
57	if (direction != DMA_TO_DEVICE)
58		t |= (1 << TCE_WRITE_SHIFT);
59
60	tp = ((u64*)tbl->it_base) + index;
61
62	while (npages--) {
63		rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
64		t &= ~TCE_RPN_MASK;
65		t |= (rpn << TCE_RPN_SHIFT);
66
67		*tp = cpu_to_be64(t);
68		flush_tce(tp);
69
70		uaddr += PAGE_SIZE;
71		tp++;
72	}
73}
74
75void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
76{
77	u64* tp;
78
79	tp  = ((u64*)tbl->it_base) + index;
80
81	while (npages--) {
82		*tp = cpu_to_be64(0);
83		flush_tce(tp);
84		tp++;
85	}
86}
87
88static inline unsigned int table_size_to_number_of_entries(unsigned char size)
89{
90	/*
91	 * size is the order of the table, 0-7
92	 * smallest table is 8K entries, so shift result by 13 to
93	 * multiply by 8K
94	 */
95	return (1 << size) << 13;
96}
97
98static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
99{
100	unsigned int bitmapsz;
101	unsigned long bmppages;
102	int ret;
103
104	tbl->it_busno = dev->bus->number;
105
106	/* set the tce table size - measured in entries */
107	tbl->it_size = table_size_to_number_of_entries(specified_table_size);
108
109	/*
110	 * number of bytes needed for the bitmap size in number of
111	 * entries; we need one bit per entry
112	 */
113	bitmapsz = tbl->it_size / BITS_PER_BYTE;
114	bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
115	if (!bmppages) {
116		printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
117		ret = -ENOMEM;
118		goto done;
119	}
120
121	tbl->it_map = (unsigned long*)bmppages;
122
123	memset(tbl->it_map, 0, bitmapsz);
124
125	tbl->it_hint = 0;
126
127	spin_lock_init(&tbl->it_lock);
128
129	return 0;
130
131done:
132	return ret;
133}
134
135int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
136{
137	struct iommu_table *tbl;
138	int ret;
139
140	if (pci_iommu(dev->bus)) {
141		printk(KERN_ERR "Calgary: dev %p has sysdata->iommu %p\n",
142		       dev, pci_iommu(dev->bus));
143		BUG();
144	}
145
146	tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
147	if (!tbl) {
148		printk(KERN_ERR "Calgary: error allocating iommu_table\n");
149		ret = -ENOMEM;
150		goto done;
151	}
152
153	ret = tce_table_setparms(dev, tbl);
154	if (ret)
155		goto free_tbl;
156
157	tbl->bbar = bbar;
158
159	set_pci_iommu(dev->bus, tbl);
160
161	return 0;
162
163free_tbl:
164	kfree(tbl);
165done:
166	return ret;
167}
168
169void * __init alloc_tce_table(void)
170{
171	unsigned int size;
172
173	size = table_size_to_number_of_entries(specified_table_size);
174	size *= TCE_ENTRY_SIZE;
175
176	return __alloc_bootmem_low(size, size, 0);
177}
178
179void __init free_tce_table(void *tbl)
180{
181	unsigned int size;
182
183	if (!tbl)
184		return;
185
186	size = table_size_to_number_of_entries(specified_table_size);
187	size *= TCE_ENTRY_SIZE;
188
189	free_bootmem(__pa(tbl), size);
190}
191