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 IOB_BASE		0xe0000000
35 #define IOB_SIZE		0x3000
36 /* Configuration registers */
37 #define IOBCAP_REG		0x10
38 #define IOBCOM_REG		0x40
39 /* Enable IOB address translation */
40 #define IOBCOM_ATEN		0x00000100
41 
42 /* Address decode configuration register */
43 #define IOB_AD_REG		0x53
44 /* IOBCOM_AD_REG fields */
45 #define IOB_AD_VGPRT		0x00000e00
46 #define IOB_AD_VGAEN		0x00000100
47 /* Direct mapping settings */
48 #define IOB_AD_MPSEL_MASK	0x00000030
49 #define IOB_AD_MPSEL_B38	0x00000000
50 #define IOB_AD_MPSEL_B40	0x00000010
51 #define IOB_AD_MPSEL_B42	0x00000020
52 /* Translation window size / enable */
53 #define IOB_AD_TRNG_MASK	0x00000003
54 #define IOB_AD_TRNG_256M	0x00000000
55 #define IOB_AD_TRNG_2G		0x00000001
56 #define IOB_AD_TRNG_128G	0x00000003
57 
58 #define IOB_TABLEBASE_REG	0x55
59 
60 /* Base of the 64 4-byte L1 registers */
61 #define IOB_XLT_L1_REGBASE	0xac0
62 
63 /* Register to invalidate TLB entries */
64 #define IOB_AT_INVAL_TLB_REG	0xb40
65 
66 /* The top two bits of the level 1 entry contains valid and type flags */
67 #define IOBMAP_L1E_V		0x40000000
68 #define IOBMAP_L1E_V_B		0x80000000
69 
70 /* For big page entries, the bottom two bits contains flags */
71 #define IOBMAP_L1E_BIG_CACHED	0x00000002
72 #define IOBMAP_L1E_BIG_PRIORITY	0x00000001
73 
74 /* For regular level 2 entries, top 2 bits contain valid and cache flags */
75 #define IOBMAP_L2E_V		0x80000000
76 #define IOBMAP_L2E_V_CACHED	0xc0000000
77 
78 static u32 __iomem *iob;
79 static u32 iob_l1_emptyval;
80 static u32 iob_l2_emptyval;
81 static u32 *iob_l2_base;
82 
83 static struct iommu_table iommu_table_iobmap;
84 static int iommu_table_iobmap_inited;
85 
86 static void iobmap_build(struct iommu_table *tbl, long index,
87 			 long npages, unsigned long uaddr,
88 			 enum dma_data_direction direction)
89 {
90 	u32 *ip;
91 	u32 rpn;
92 	unsigned long bus_addr;
93 
94 	pr_debug("iobmap: build at: %lx, %lx, addr: %lx\n", index, npages, uaddr);
95 
96 	bus_addr = (tbl->it_offset + index) << PAGE_SHIFT;
97 
98 	ip = ((u32 *)tbl->it_base) + index;
99 
100 	while (npages--) {
101 		rpn = virt_to_abs(uaddr) >> IOBMAP_PAGE_SHIFT;
102 
103 		*(ip++) = IOBMAP_L2E_V | rpn;
104 		/* invalidate tlb, can be optimized more */
105 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
106 
107 		uaddr += IOBMAP_PAGE_SIZE;
108 		bus_addr += IOBMAP_PAGE_SIZE;
109 	}
110 }
111 
112 
113 static void iobmap_free(struct iommu_table *tbl, long index,
114 			long npages)
115 {
116 	u32 *ip;
117 	unsigned long bus_addr;
118 
119 	pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
120 
121 	bus_addr = (tbl->it_offset + index) << PAGE_SHIFT;
122 
123 	ip = ((u32 *)tbl->it_base) + index;
124 
125 	while (npages--) {
126 		*(ip++) = iob_l2_emptyval;
127 		/* invalidate tlb, can be optimized more */
128 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
129 		bus_addr += IOBMAP_PAGE_SIZE;
130 	}
131 }
132 
133 
134 static void iommu_table_iobmap_setup(void)
135 {
136 	pr_debug(" -> %s\n", __func__);
137 	iommu_table_iobmap.it_busno = 0;
138 	iommu_table_iobmap.it_offset = 0;
139 	/* it_size is in number of entries */
140 	iommu_table_iobmap.it_size = 0x80000000 >> PAGE_SHIFT;
141 
142 	/* Initialize the common IOMMU code */
143 	iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
144 	iommu_table_iobmap.it_index = 0;
145 	/* XXXOJN tune this to avoid IOB cache invals.
146 	 * Should probably be 8 (64 bytes)
147 	 */
148 	iommu_table_iobmap.it_blocksize = 4;
149 	iommu_init_table(&iommu_table_iobmap, 0);
150 	pr_debug(" <- %s\n", __func__);
151 }
152 
153 
154 
155 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
156 {
157 	struct device_node *dn;
158 
159 	pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
160 
161 	if (!iommu_table_iobmap_inited) {
162 		iommu_table_iobmap_inited = 1;
163 		iommu_table_iobmap_setup();
164 	}
165 
166 	dn = pci_bus_to_OF_node(bus);
167 
168 	if (dn)
169 		PCI_DN(dn)->iommu_table = &iommu_table_iobmap;
170 
171 }
172 
173 
174 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
175 {
176 	pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
177 
178 	/* DMA device is untranslated, but all other PCI-e goes through
179 	 * the IOMMU
180 	 */
181 	if (dev->vendor == 0x1959 && dev->device == 0xa007)
182 		dev->dev.archdata.dma_ops = &dma_direct_ops;
183 	else
184 		dev->dev.archdata.dma_data = &iommu_table_iobmap;
185 }
186 
187 static void pci_dma_bus_setup_null(struct pci_bus *b) { }
188 static void pci_dma_dev_setup_null(struct pci_dev *d) { }
189 
190 int iob_init(struct device_node *dn)
191 {
192 	unsigned long tmp;
193 	u32 regword;
194 	int i;
195 
196 	pr_debug(" -> %s\n", __func__);
197 
198 	/* Allocate a spare page to map all invalid IOTLB pages. */
199 	tmp = lmb_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
200 	if (!tmp)
201 		panic("IOBMAP: Cannot allocate spare page!");
202 	/* Empty l1 is marked invalid */
203 	iob_l1_emptyval = 0;
204 	/* Empty l2 is mapped to dummy page */
205 	iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
206 
207 	iob = ioremap(IOB_BASE, IOB_SIZE);
208 	if (!iob)
209 		panic("IOBMAP: Cannot map registers!");
210 
211 	/* setup direct mapping of the L1 entries */
212 	for (i = 0; i < 64; i++) {
213 		/* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
214 		regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
215 		out_le32(iob+IOB_XLT_L1_REGBASE+i, regword);
216 	}
217 
218 	/* set 2GB translation window, based at 0 */
219 	regword = in_le32(iob+IOB_AD_REG);
220 	regword &= ~IOB_AD_TRNG_MASK;
221 	regword |= IOB_AD_TRNG_2G;
222 	out_le32(iob+IOB_AD_REG, regword);
223 
224 	/* Enable translation */
225 	regword = in_le32(iob+IOBCOM_REG);
226 	regword |= IOBCOM_ATEN;
227 	out_le32(iob+IOBCOM_REG, regword);
228 
229 	pr_debug(" <- %s\n", __func__);
230 
231 	return 0;
232 }
233 
234 
235 /* These are called very early. */
236 void iommu_init_early_pasemi(void)
237 {
238 	int iommu_off;
239 
240 #ifndef CONFIG_PPC_PASEMI_IOMMU
241 	iommu_off = 1;
242 #else
243 	iommu_off = of_chosen &&
244 			of_get_property(of_chosen, "linux,iommu-off", NULL);
245 #endif
246 	if (iommu_off) {
247 		/* Direct I/O, IOMMU off */
248 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_null;
249 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_null;
250 		set_pci_dma_ops(&dma_direct_ops);
251 
252 		return;
253 	}
254 
255 	iob_init(NULL);
256 
257 	ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pasemi;
258 	ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pasemi;
259 	ppc_md.tce_build = iobmap_build;
260 	ppc_md.tce_free  = iobmap_free;
261 	set_pci_dma_ops(&dma_iommu_ops);
262 }
263 
264 void __init alloc_iobmap_l2(void)
265 {
266 #ifndef CONFIG_PPC_PASEMI_IOMMU
267 	return;
268 #endif
269 	/* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
270 	iob_l2_base = (u32 *)abs_to_virt(lmb_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
271 
272 	printk(KERN_INFO "IOBMAP L2 allocated at: %p\n", iob_l2_base);
273 }
274