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 #include "pasemi.h"
31 
32 #define IOBMAP_PAGE_SHIFT	12
33 #define IOBMAP_PAGE_SIZE	(1 << IOBMAP_PAGE_SHIFT)
34 #define IOBMAP_PAGE_MASK	(IOBMAP_PAGE_SIZE - 1)
35 
36 #define IOB_BASE		0xe0000000
37 #define IOB_SIZE		0x3000
38 /* Configuration registers */
39 #define IOBCAP_REG		0x40
40 #define IOBCOM_REG		0x100
41 /* Enable IOB address translation */
42 #define IOBCOM_ATEN		0x00000100
43 
44 /* Address decode configuration register */
45 #define IOB_AD_REG		0x14c
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	0x154
61 
62 /* Base of the 64 4-byte L1 registers */
63 #define IOB_XLT_L1_REGBASE	0x2b00
64 
65 /* Register to invalidate TLB entries */
66 #define IOB_AT_INVAL_TLB_REG	0x2d00
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 void __iomem *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 int iobmap_build(struct iommu_table *tbl, long index,
89 			 long npages, unsigned long uaddr,
90 			 enum dma_data_direction direction,
91 			 unsigned long attrs)
92 {
93 	u32 *ip;
94 	u32 rpn;
95 	unsigned long bus_addr;
96 
97 	pr_debug("iobmap: build at: %lx, %lx, addr: %lx\n", index, npages, uaddr);
98 
99 	bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
100 
101 	ip = ((u32 *)tbl->it_base) + index;
102 
103 	while (npages--) {
104 		rpn = __pa(uaddr) >> IOBMAP_PAGE_SHIFT;
105 
106 		*(ip++) = IOBMAP_L2E_V | rpn;
107 		/* invalidate tlb, can be optimized more */
108 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
109 
110 		uaddr += IOBMAP_PAGE_SIZE;
111 		bus_addr += IOBMAP_PAGE_SIZE;
112 	}
113 	return 0;
114 }
115 
116 
117 static void iobmap_free(struct iommu_table *tbl, long index,
118 			long npages)
119 {
120 	u32 *ip;
121 	unsigned long bus_addr;
122 
123 	pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
124 
125 	bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
126 
127 	ip = ((u32 *)tbl->it_base) + index;
128 
129 	while (npages--) {
130 		*(ip++) = iob_l2_emptyval;
131 		/* invalidate tlb, can be optimized more */
132 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
133 		bus_addr += IOBMAP_PAGE_SIZE;
134 	}
135 }
136 
137 static struct iommu_table_ops iommu_table_iobmap_ops = {
138 	.set = iobmap_build,
139 	.clear  = iobmap_free
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 	iommu_table_iobmap.it_page_shift = IOBMAP_PAGE_SHIFT;
148 
149 	/* it_size is in number of entries */
150 	iommu_table_iobmap.it_size =
151 		0x80000000 >> iommu_table_iobmap.it_page_shift;
152 
153 	/* Initialize the common IOMMU code */
154 	iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
155 	iommu_table_iobmap.it_index = 0;
156 	/* XXXOJN tune this to avoid IOB cache invals.
157 	 * Should probably be 8 (64 bytes)
158 	 */
159 	iommu_table_iobmap.it_blocksize = 4;
160 	iommu_table_iobmap.it_ops = &iommu_table_iobmap_ops;
161 	iommu_init_table(&iommu_table_iobmap, 0);
162 	pr_debug(" <- %s\n", __func__);
163 }
164 
165 
166 
167 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
168 {
169 	pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
170 
171 	if (!iommu_table_iobmap_inited) {
172 		iommu_table_iobmap_inited = 1;
173 		iommu_table_iobmap_setup();
174 	}
175 }
176 
177 
178 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
179 {
180 	pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
181 
182 #if !defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
183 	/* For non-LPAR environment, don't translate anything for the DMA
184 	 * engine. The exception to this is if the user has enabled
185 	 * CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE at build time.
186 	 */
187 	if (dev->vendor == 0x1959 && dev->device == 0xa007 &&
188 	    !firmware_has_feature(FW_FEATURE_LPAR)) {
189 		dev->dev.dma_ops = &dma_nommu_ops;
190 		/*
191 		 * Set the coherent DMA mask to prevent the iommu
192 		 * being used unnecessarily
193 		 */
194 		dev->dev.coherent_dma_mask = DMA_BIT_MASK(44);
195 		return;
196 	}
197 #endif
198 
199 	set_iommu_table_base(&dev->dev, &iommu_table_iobmap);
200 }
201 
202 static int __init iob_init(struct device_node *dn)
203 {
204 	unsigned long tmp;
205 	u32 regword;
206 	int i;
207 
208 	pr_debug(" -> %s\n", __func__);
209 
210 	/* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
211 	iob_l2_base = (u32 *)__va(memblock_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
212 
213 	pr_info("IOBMAP L2 allocated at: %p\n", iob_l2_base);
214 
215 	/* Allocate a spare page to map all invalid IOTLB pages. */
216 	tmp = memblock_phys_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
217 	if (!tmp)
218 		panic("IOBMAP: Cannot allocate spare page!");
219 	/* Empty l1 is marked invalid */
220 	iob_l1_emptyval = 0;
221 	/* Empty l2 is mapped to dummy page */
222 	iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
223 
224 	iob = ioremap(IOB_BASE, IOB_SIZE);
225 	if (!iob)
226 		panic("IOBMAP: Cannot map registers!");
227 
228 	/* setup direct mapping of the L1 entries */
229 	for (i = 0; i < 64; i++) {
230 		/* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
231 		regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
232 		out_le32(iob+IOB_XLT_L1_REGBASE+i*4, regword);
233 	}
234 
235 	/* set 2GB translation window, based at 0 */
236 	regword = in_le32(iob+IOB_AD_REG);
237 	regword &= ~IOB_AD_TRNG_MASK;
238 	regword |= IOB_AD_TRNG_2G;
239 	out_le32(iob+IOB_AD_REG, regword);
240 
241 	/* Enable translation */
242 	regword = in_le32(iob+IOBCOM_REG);
243 	regword |= IOBCOM_ATEN;
244 	out_le32(iob+IOBCOM_REG, regword);
245 
246 	pr_debug(" <- %s\n", __func__);
247 
248 	return 0;
249 }
250 
251 
252 /* These are called very early. */
253 void __init iommu_init_early_pasemi(void)
254 {
255 	int iommu_off;
256 
257 #ifndef CONFIG_PPC_PASEMI_IOMMU
258 	iommu_off = 1;
259 #else
260 	iommu_off = of_chosen &&
261 			of_get_property(of_chosen, "linux,iommu-off", NULL);
262 #endif
263 	if (iommu_off)
264 		return;
265 
266 	iob_init(NULL);
267 
268 	pasemi_pci_controller_ops.dma_dev_setup = pci_dma_dev_setup_pasemi;
269 	pasemi_pci_controller_ops.dma_bus_setup = pci_dma_bus_setup_pasemi;
270 	set_pci_dma_ops(&dma_iommu_ops);
271 }
272 
273