1 /*
2  * Copyright (C) 2005-2008, 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/memblock.h>
23 #include <linux/types.h>
24 #include <linux/spinlock.h>
25 #include <linux/pci.h>
26 #include <asm/iommu.h>
27 #include <asm/machdep.h>
28 #include <asm/firmware.h>
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		0x40
38 #define IOBCOM_REG		0x100
39 /* Enable IOB address translation */
40 #define IOBCOM_ATEN		0x00000100
41 
42 /* Address decode configuration register */
43 #define IOB_AD_REG		0x14c
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	0x154
59 
60 /* Base of the 64 4-byte L1 registers */
61 #define IOB_XLT_L1_REGBASE	0x2b00
62 
63 /* Register to invalidate TLB entries */
64 #define IOB_AT_INVAL_TLB_REG	0x2d00
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 void __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 int iobmap_build(struct iommu_table *tbl, long index,
87 			 long npages, unsigned long uaddr,
88 			 enum dma_data_direction direction,
89 			 struct dma_attrs *attrs)
90 {
91 	u32 *ip;
92 	u32 rpn;
93 	unsigned long bus_addr;
94 
95 	pr_debug("iobmap: build at: %lx, %lx, addr: %lx\n", index, npages, uaddr);
96 
97 	bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
98 
99 	ip = ((u32 *)tbl->it_base) + index;
100 
101 	while (npages--) {
102 		rpn = __pa(uaddr) >> IOBMAP_PAGE_SHIFT;
103 
104 		*(ip++) = IOBMAP_L2E_V | rpn;
105 		/* invalidate tlb, can be optimized more */
106 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
107 
108 		uaddr += IOBMAP_PAGE_SIZE;
109 		bus_addr += IOBMAP_PAGE_SIZE;
110 	}
111 	return 0;
112 }
113 
114 
115 static void iobmap_free(struct iommu_table *tbl, long index,
116 			long npages)
117 {
118 	u32 *ip;
119 	unsigned long bus_addr;
120 
121 	pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
122 
123 	bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
124 
125 	ip = ((u32 *)tbl->it_base) + index;
126 
127 	while (npages--) {
128 		*(ip++) = iob_l2_emptyval;
129 		/* invalidate tlb, can be optimized more */
130 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
131 		bus_addr += IOBMAP_PAGE_SIZE;
132 	}
133 }
134 
135 
136 static void iommu_table_iobmap_setup(void)
137 {
138 	pr_debug(" -> %s\n", __func__);
139 	iommu_table_iobmap.it_busno = 0;
140 	iommu_table_iobmap.it_offset = 0;
141 	/* it_size is in number of entries */
142 	iommu_table_iobmap.it_size = 0x80000000 >> IOBMAP_PAGE_SHIFT;
143 
144 	/* Initialize the common IOMMU code */
145 	iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
146 	iommu_table_iobmap.it_index = 0;
147 	/* XXXOJN tune this to avoid IOB cache invals.
148 	 * Should probably be 8 (64 bytes)
149 	 */
150 	iommu_table_iobmap.it_blocksize = 4;
151 	iommu_init_table(&iommu_table_iobmap, 0);
152 	pr_debug(" <- %s\n", __func__);
153 }
154 
155 
156 
157 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
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 
167 
168 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
169 {
170 	pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
171 
172 #if !defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
173 	/* For non-LPAR environment, don't translate anything for the DMA
174 	 * engine. The exception to this is if the user has enabled
175 	 * CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE at build time.
176 	 */
177 	if (dev->vendor == 0x1959 && dev->device == 0xa007 &&
178 	    !firmware_has_feature(FW_FEATURE_LPAR)) {
179 		dev->dev.archdata.dma_ops = &dma_direct_ops;
180 		return;
181 	}
182 #endif
183 
184 	set_iommu_table_base(&dev->dev, &iommu_table_iobmap);
185 }
186 
187 int __init iob_init(struct device_node *dn)
188 {
189 	unsigned long tmp;
190 	u32 regword;
191 	int i;
192 
193 	pr_debug(" -> %s\n", __func__);
194 
195 	/* Allocate a spare page to map all invalid IOTLB pages. */
196 	tmp = memblock_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
197 	if (!tmp)
198 		panic("IOBMAP: Cannot allocate spare page!");
199 	/* Empty l1 is marked invalid */
200 	iob_l1_emptyval = 0;
201 	/* Empty l2 is mapped to dummy page */
202 	iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
203 
204 	iob = ioremap(IOB_BASE, IOB_SIZE);
205 	if (!iob)
206 		panic("IOBMAP: Cannot map registers!");
207 
208 	/* setup direct mapping of the L1 entries */
209 	for (i = 0; i < 64; i++) {
210 		/* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
211 		regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
212 		out_le32(iob+IOB_XLT_L1_REGBASE+i*4, regword);
213 	}
214 
215 	/* set 2GB translation window, based at 0 */
216 	regword = in_le32(iob+IOB_AD_REG);
217 	regword &= ~IOB_AD_TRNG_MASK;
218 	regword |= IOB_AD_TRNG_2G;
219 	out_le32(iob+IOB_AD_REG, regword);
220 
221 	/* Enable translation */
222 	regword = in_le32(iob+IOBCOM_REG);
223 	regword |= IOBCOM_ATEN;
224 	out_le32(iob+IOBCOM_REG, regword);
225 
226 	pr_debug(" <- %s\n", __func__);
227 
228 	return 0;
229 }
230 
231 
232 /* These are called very early. */
233 void __init iommu_init_early_pasemi(void)
234 {
235 	int iommu_off;
236 
237 #ifndef CONFIG_PPC_PASEMI_IOMMU
238 	iommu_off = 1;
239 #else
240 	iommu_off = of_chosen &&
241 			of_get_property(of_chosen, "linux,iommu-off", NULL);
242 #endif
243 	if (iommu_off)
244 		return;
245 
246 	iob_init(NULL);
247 
248 	ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pasemi;
249 	ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pasemi;
250 	ppc_md.tce_build = iobmap_build;
251 	ppc_md.tce_free  = iobmap_free;
252 	set_pci_dma_ops(&dma_iommu_ops);
253 }
254 
255 void __init alloc_iobmap_l2(void)
256 {
257 #ifndef CONFIG_PPC_PASEMI_IOMMU
258 	return;
259 #endif
260 	/* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
261 	iob_l2_base = (u32 *)__va(memblock_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
262 
263 	printk(KERN_INFO "IOBMAP L2 allocated at: %p\n", iob_l2_base);
264 }
265