xref: /linux/arch/powerpc/platforms/pasemi/iommu.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  * Copyright (C) 2005-2007, PA Semi, Inc
3  *
4  * Maintained by: Olof Johansson <olof@lixom.net>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18  */
19 
20 #undef DEBUG
21 
22 #include <linux/types.h>
23 #include <linux/spinlock.h>
24 #include <linux/pci.h>
25 #include <asm/iommu.h>
26 #include <asm/machdep.h>
27 #include <asm/abs_addr.h>
28 
29 
30 #define IOBMAP_PAGE_SHIFT	12
31 #define IOBMAP_PAGE_SIZE	(1 << IOBMAP_PAGE_SHIFT)
32 #define IOBMAP_PAGE_MASK	(IOBMAP_PAGE_SIZE - 1)
33 
34 #define IOBMAP_PAGE_FACTOR	(PAGE_SHIFT - IOBMAP_PAGE_SHIFT)
35 
36 #define IOB_BASE		0xe0000000
37 #define IOB_SIZE		0x3000
38 /* Configuration registers */
39 #define IOBCAP_REG		0x10
40 #define IOBCOM_REG		0x40
41 /* Enable IOB address translation */
42 #define IOBCOM_ATEN		0x00000100
43 
44 /* Address decode configuration register */
45 #define IOB_AD_REG		0x53
46 /* IOBCOM_AD_REG fields */
47 #define IOB_AD_VGPRT		0x00000e00
48 #define IOB_AD_VGAEN		0x00000100
49 /* Direct mapping settings */
50 #define IOB_AD_MPSEL_MASK	0x00000030
51 #define IOB_AD_MPSEL_B38	0x00000000
52 #define IOB_AD_MPSEL_B40	0x00000010
53 #define IOB_AD_MPSEL_B42	0x00000020
54 /* Translation window size / enable */
55 #define IOB_AD_TRNG_MASK	0x00000003
56 #define IOB_AD_TRNG_256M	0x00000000
57 #define IOB_AD_TRNG_2G		0x00000001
58 #define IOB_AD_TRNG_128G	0x00000003
59 
60 #define IOB_TABLEBASE_REG	0x55
61 
62 /* Base of the 64 4-byte L1 registers */
63 #define IOB_XLT_L1_REGBASE	0xac0
64 
65 /* Register to invalidate TLB entries */
66 #define IOB_AT_INVAL_TLB_REG	0xb40
67 
68 /* The top two bits of the level 1 entry contains valid and type flags */
69 #define IOBMAP_L1E_V		0x40000000
70 #define IOBMAP_L1E_V_B		0x80000000
71 
72 /* For big page entries, the bottom two bits contains flags */
73 #define IOBMAP_L1E_BIG_CACHED	0x00000002
74 #define IOBMAP_L1E_BIG_PRIORITY	0x00000001
75 
76 /* For regular level 2 entries, top 2 bits contain valid and cache flags */
77 #define IOBMAP_L2E_V		0x80000000
78 #define IOBMAP_L2E_V_CACHED	0xc0000000
79 
80 static u32 *iob;
81 static u32 iob_l1_emptyval;
82 static u32 iob_l2_emptyval;
83 static u32 *iob_l2_base;
84 
85 static struct iommu_table iommu_table_iobmap;
86 static int iommu_table_iobmap_inited;
87 
88 static void iobmap_build(struct iommu_table *tbl, long index,
89 			 long npages, unsigned long uaddr,
90 			 enum dma_data_direction direction)
91 {
92 	u32 *ip;
93 	u32 rpn;
94 	unsigned long bus_addr;
95 
96 	pr_debug("iobmap: build at: %lx, %lx, addr: %lx\n", index, npages, uaddr);
97 
98 	bus_addr = (tbl->it_offset + index) << PAGE_SHIFT;
99 
100 	npages <<= IOBMAP_PAGE_FACTOR;
101 	index <<= IOBMAP_PAGE_FACTOR;
102 
103 	ip = ((u32 *)tbl->it_base) + index;
104 
105 	while (npages--) {
106 		rpn = virt_to_abs(uaddr) >> IOBMAP_PAGE_SHIFT;
107 
108 		*(ip++) = IOBMAP_L2E_V | rpn;
109 		/* invalidate tlb, can be optimized more */
110 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
111 
112 		uaddr += IOBMAP_PAGE_SIZE;
113 		bus_addr += IOBMAP_PAGE_SIZE;
114 	}
115 }
116 
117 
118 static void iobmap_free(struct iommu_table *tbl, long index,
119 			long npages)
120 {
121 	u32 *ip;
122 	unsigned long bus_addr;
123 
124 	pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
125 
126 	bus_addr = (tbl->it_offset + index) << PAGE_SHIFT;
127 
128 	npages <<= IOBMAP_PAGE_FACTOR;
129 	index <<= IOBMAP_PAGE_FACTOR;
130 
131 	ip = ((u32 *)tbl->it_base) + index;
132 
133 	while (npages--) {
134 		*(ip++) = iob_l2_emptyval;
135 		/* invalidate tlb, can be optimized more */
136 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
137 		bus_addr += IOBMAP_PAGE_SIZE;
138 	}
139 }
140 
141 
142 static void iommu_table_iobmap_setup(void)
143 {
144 	pr_debug(" -> %s\n", __func__);
145 	iommu_table_iobmap.it_busno = 0;
146 	iommu_table_iobmap.it_offset = 0;
147 	/* it_size is in number of entries */
148 	iommu_table_iobmap.it_size = 0x80000000 >> PAGE_SHIFT;
149 
150 	/* Initialize the common IOMMU code */
151 	iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
152 	iommu_table_iobmap.it_index = 0;
153 	/* XXXOJN tune this to avoid IOB cache invals.
154 	 * Should probably be 8 (64 bytes)
155 	 */
156 	iommu_table_iobmap.it_blocksize = 4;
157 	iommu_init_table(&iommu_table_iobmap, 0);
158 	pr_debug(" <- %s\n", __func__);
159 }
160 
161 
162 
163 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
164 {
165 	struct device_node *dn;
166 
167 	pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
168 
169 	if (!iommu_table_iobmap_inited) {
170 		iommu_table_iobmap_inited = 1;
171 		iommu_table_iobmap_setup();
172 	}
173 
174 	dn = pci_bus_to_OF_node(bus);
175 
176 	if (dn)
177 		PCI_DN(dn)->iommu_table = &iommu_table_iobmap;
178 
179 }
180 
181 
182 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
183 {
184 	pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
185 
186 	/* DMA device is untranslated, but all other PCI-e goes through
187 	 * the IOMMU
188 	 */
189 	if (dev->vendor == 0x1959 && dev->device == 0xa007)
190 		dev->dev.archdata.dma_ops = &dma_direct_ops;
191 	else
192 		dev->dev.archdata.dma_data = &iommu_table_iobmap;
193 }
194 
195 static void pci_dma_bus_setup_null(struct pci_bus *b) { }
196 static void pci_dma_dev_setup_null(struct pci_dev *d) { }
197 
198 int iob_init(struct device_node *dn)
199 {
200 	unsigned long tmp;
201 	u32 regword;
202 	int i;
203 
204 	pr_debug(" -> %s\n", __func__);
205 
206 	/* Allocate a spare page to map all invalid IOTLB pages. */
207 	tmp = lmb_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
208 	if (!tmp)
209 		panic("IOBMAP: Cannot allocate spare page!");
210 	/* Empty l1 is marked invalid */
211 	iob_l1_emptyval = 0;
212 	/* Empty l2 is mapped to dummy page */
213 	iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
214 
215 	iob = ioremap(IOB_BASE, IOB_SIZE);
216 	if (!iob)
217 		panic("IOBMAP: Cannot map registers!");
218 
219 	/* setup direct mapping of the L1 entries */
220 	for (i = 0; i < 64; i++) {
221 		/* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
222 		regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
223 		out_le32(iob+IOB_XLT_L1_REGBASE+i, regword);
224 	}
225 
226 	/* set 2GB translation window, based at 0 */
227 	regword = in_le32(iob+IOB_AD_REG);
228 	regword &= ~IOB_AD_TRNG_MASK;
229 	regword |= IOB_AD_TRNG_2G;
230 	out_le32(iob+IOB_AD_REG, regword);
231 
232 	/* Enable translation */
233 	regword = in_le32(iob+IOBCOM_REG);
234 	regword |= IOBCOM_ATEN;
235 	out_le32(iob+IOBCOM_REG, regword);
236 
237 	pr_debug(" <- %s\n", __func__);
238 
239 	return 0;
240 }
241 
242 
243 /* These are called very early. */
244 void iommu_init_early_pasemi(void)
245 {
246 	int iommu_off;
247 
248 #ifndef CONFIG_PPC_PASEMI_IOMMU
249 	iommu_off = 1;
250 #else
251 	iommu_off = of_chosen &&
252 			get_property(of_chosen, "linux,iommu-off", NULL);
253 #endif
254 	if (iommu_off) {
255 		/* Direct I/O, IOMMU off */
256 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_null;
257 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_null;
258 		pci_dma_ops = &dma_direct_ops;
259 
260 		return;
261 	}
262 
263 	iob_init(NULL);
264 
265 	ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pasemi;
266 	ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pasemi;
267 	ppc_md.tce_build = iobmap_build;
268 	ppc_md.tce_free  = iobmap_free;
269 	pci_dma_ops = &dma_iommu_ops;
270 }
271 
272 void __init alloc_iobmap_l2(void)
273 {
274 #ifndef CONFIG_PPC_PASEMI_IOMMU
275 	return;
276 #endif
277 	/* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
278 	iob_l2_base = (u32 *)abs_to_virt(lmb_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
279 
280 	printk(KERN_INFO "IOBMAP L2 allocated at: %p\n", iob_l2_base);
281 }
282