xref: /openbmc/linux/arch/powerpc/platforms/pasemi/iommu.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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 #include <asm/firmware.h>
29 
30 
31 #define IOBMAP_PAGE_SHIFT	12
32 #define IOBMAP_PAGE_SIZE	(1 << IOBMAP_PAGE_SHIFT)
33 #define IOBMAP_PAGE_MASK	(IOBMAP_PAGE_SIZE - 1)
34 
35 #define IOB_BASE		0xe0000000
36 #define IOB_SIZE		0x3000
37 /* Configuration registers */
38 #define IOBCAP_REG		0x10
39 #define IOBCOM_REG		0x40
40 /* Enable IOB address translation */
41 #define IOBCOM_ATEN		0x00000100
42 
43 /* Address decode configuration register */
44 #define IOB_AD_REG		0x53
45 /* IOBCOM_AD_REG fields */
46 #define IOB_AD_VGPRT		0x00000e00
47 #define IOB_AD_VGAEN		0x00000100
48 /* Direct mapping settings */
49 #define IOB_AD_MPSEL_MASK	0x00000030
50 #define IOB_AD_MPSEL_B38	0x00000000
51 #define IOB_AD_MPSEL_B40	0x00000010
52 #define IOB_AD_MPSEL_B42	0x00000020
53 /* Translation window size / enable */
54 #define IOB_AD_TRNG_MASK	0x00000003
55 #define IOB_AD_TRNG_256M	0x00000000
56 #define IOB_AD_TRNG_2G		0x00000001
57 #define IOB_AD_TRNG_128G	0x00000003
58 
59 #define IOB_TABLEBASE_REG	0x55
60 
61 /* Base of the 64 4-byte L1 registers */
62 #define IOB_XLT_L1_REGBASE	0xac0
63 
64 /* Register to invalidate TLB entries */
65 #define IOB_AT_INVAL_TLB_REG	0xb40
66 
67 /* The top two bits of the level 1 entry contains valid and type flags */
68 #define IOBMAP_L1E_V		0x40000000
69 #define IOBMAP_L1E_V_B		0x80000000
70 
71 /* For big page entries, the bottom two bits contains flags */
72 #define IOBMAP_L1E_BIG_CACHED	0x00000002
73 #define IOBMAP_L1E_BIG_PRIORITY	0x00000001
74 
75 /* For regular level 2 entries, top 2 bits contain valid and cache flags */
76 #define IOBMAP_L2E_V		0x80000000
77 #define IOBMAP_L2E_V_CACHED	0xc0000000
78 
79 static u32 __iomem *iob;
80 static u32 iob_l1_emptyval;
81 static u32 iob_l2_emptyval;
82 static u32 *iob_l2_base;
83 
84 static struct iommu_table iommu_table_iobmap;
85 static int iommu_table_iobmap_inited;
86 
87 static void iobmap_build(struct iommu_table *tbl, long index,
88 			 long npages, unsigned long uaddr,
89 			 enum dma_data_direction direction)
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 = virt_to_abs(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 }
112 
113 
114 static void iobmap_free(struct iommu_table *tbl, long index,
115 			long npages)
116 {
117 	u32 *ip;
118 	unsigned long bus_addr;
119 
120 	pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
121 
122 	bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
123 
124 	ip = ((u32 *)tbl->it_base) + index;
125 
126 	while (npages--) {
127 		*(ip++) = iob_l2_emptyval;
128 		/* invalidate tlb, can be optimized more */
129 		out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
130 		bus_addr += IOBMAP_PAGE_SIZE;
131 	}
132 }
133 
134 
135 static void iommu_table_iobmap_setup(void)
136 {
137 	pr_debug(" -> %s\n", __func__);
138 	iommu_table_iobmap.it_busno = 0;
139 	iommu_table_iobmap.it_offset = 0;
140 	/* it_size is in number of entries */
141 	iommu_table_iobmap.it_size = 0x80000000 >> IOBMAP_PAGE_SHIFT;
142 
143 	/* Initialize the common IOMMU code */
144 	iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
145 	iommu_table_iobmap.it_index = 0;
146 	/* XXXOJN tune this to avoid IOB cache invals.
147 	 * Should probably be 8 (64 bytes)
148 	 */
149 	iommu_table_iobmap.it_blocksize = 4;
150 	iommu_init_table(&iommu_table_iobmap, 0);
151 	pr_debug(" <- %s\n", __func__);
152 }
153 
154 
155 
156 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
157 {
158 	struct device_node *dn;
159 
160 	pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
161 
162 	if (!iommu_table_iobmap_inited) {
163 		iommu_table_iobmap_inited = 1;
164 		iommu_table_iobmap_setup();
165 	}
166 
167 	dn = pci_bus_to_OF_node(bus);
168 
169 	if (dn)
170 		PCI_DN(dn)->iommu_table = &iommu_table_iobmap;
171 
172 }
173 
174 
175 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
176 {
177 	pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
178 
179 #if !defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
180 	/* For non-LPAR environment, don't translate anything for the DMA
181 	 * engine. The exception to this is if the user has enabled
182 	 * CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE at build time.
183 	 */
184 	if (dev->vendor == 0x1959 && dev->device == 0xa007 &&
185 	    !firmware_has_feature(FW_FEATURE_LPAR))
186 		dev->dev.archdata.dma_ops = &dma_direct_ops;
187 #endif
188 
189 	dev->dev.archdata.dma_data = &iommu_table_iobmap;
190 }
191 
192 static void pci_dma_bus_setup_null(struct pci_bus *b) { }
193 static void pci_dma_dev_setup_null(struct pci_dev *d) { }
194 
195 int __init iob_init(struct device_node *dn)
196 {
197 	unsigned long tmp;
198 	u32 regword;
199 	int i;
200 
201 	pr_debug(" -> %s\n", __func__);
202 
203 	/* Allocate a spare page to map all invalid IOTLB pages. */
204 	tmp = lmb_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
205 	if (!tmp)
206 		panic("IOBMAP: Cannot allocate spare page!");
207 	/* Empty l1 is marked invalid */
208 	iob_l1_emptyval = 0;
209 	/* Empty l2 is mapped to dummy page */
210 	iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
211 
212 	iob = ioremap(IOB_BASE, IOB_SIZE);
213 	if (!iob)
214 		panic("IOBMAP: Cannot map registers!");
215 
216 	/* setup direct mapping of the L1 entries */
217 	for (i = 0; i < 64; i++) {
218 		/* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
219 		regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
220 		out_le32(iob+IOB_XLT_L1_REGBASE+i, regword);
221 	}
222 
223 	/* set 2GB translation window, based at 0 */
224 	regword = in_le32(iob+IOB_AD_REG);
225 	regword &= ~IOB_AD_TRNG_MASK;
226 	regword |= IOB_AD_TRNG_2G;
227 	out_le32(iob+IOB_AD_REG, regword);
228 
229 	/* Enable translation */
230 	regword = in_le32(iob+IOBCOM_REG);
231 	regword |= IOBCOM_ATEN;
232 	out_le32(iob+IOBCOM_REG, regword);
233 
234 	pr_debug(" <- %s\n", __func__);
235 
236 	return 0;
237 }
238 
239 
240 /* These are called very early. */
241 void __init iommu_init_early_pasemi(void)
242 {
243 	int iommu_off;
244 
245 #ifndef CONFIG_PPC_PASEMI_IOMMU
246 	iommu_off = 1;
247 #else
248 	iommu_off = of_chosen &&
249 			of_get_property(of_chosen, "linux,iommu-off", NULL);
250 #endif
251 	if (iommu_off) {
252 		/* Direct I/O, IOMMU off */
253 		ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_null;
254 		ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_null;
255 		set_pci_dma_ops(&dma_direct_ops);
256 
257 		return;
258 	}
259 
260 	iob_init(NULL);
261 
262 	ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pasemi;
263 	ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pasemi;
264 	ppc_md.tce_build = iobmap_build;
265 	ppc_md.tce_free  = iobmap_free;
266 	set_pci_dma_ops(&dma_iommu_ops);
267 }
268 
269 void __init alloc_iobmap_l2(void)
270 {
271 #ifndef CONFIG_PPC_PASEMI_IOMMU
272 	return;
273 #endif
274 	/* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
275 	iob_l2_base = (u32 *)abs_to_virt(lmb_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
276 
277 	printk(KERN_INFO "IOBMAP L2 allocated at: %p\n", iob_l2_base);
278 }
279