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1 /*
2  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
3  *
4  * Rewrite, cleanup:
5  *
6  * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
7  * Copyright (C) 2006 Olof Johansson <olof@lixom.net>
8  *
9  * Dynamic DMA mapping support, iSeries-specific parts.
10  *
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
25  */
26 
27 #include <linux/types.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/list.h>
30 #include <linux/pci.h>
31 #include <linux/module.h>
32 
33 #include <asm/iommu.h>
34 #include <asm/vio.h>
35 #include <asm/tce.h>
36 #include <asm/machdep.h>
37 #include <asm/abs_addr.h>
38 #include <asm/prom.h>
39 #include <asm/pci-bridge.h>
40 #include <asm/iseries/hv_call_xm.h>
41 #include <asm/iseries/hv_call_event.h>
42 #include <asm/iseries/iommu.h>
43 
tce_build_iSeries(struct iommu_table * tbl,long index,long npages,unsigned long uaddr,enum dma_data_direction direction,struct dma_attrs * attrs)44 static int tce_build_iSeries(struct iommu_table *tbl, long index, long npages,
45 		unsigned long uaddr, enum dma_data_direction direction,
46 		struct dma_attrs *attrs)
47 {
48 	u64 rc;
49 	u64 tce, rpn;
50 
51 	while (npages--) {
52 		rpn = virt_to_abs(uaddr) >> TCE_SHIFT;
53 		tce = (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
54 
55 		if (tbl->it_type == TCE_VB) {
56 			/* Virtual Bus */
57 			tce |= TCE_VALID|TCE_ALLIO;
58 			if (direction != DMA_TO_DEVICE)
59 				tce |= TCE_VB_WRITE;
60 		} else {
61 			/* PCI Bus */
62 			tce |= TCE_PCI_READ; /* Read allowed */
63 			if (direction != DMA_TO_DEVICE)
64 				tce |= TCE_PCI_WRITE;
65 		}
66 
67 		rc = HvCallXm_setTce((u64)tbl->it_index, (u64)index, tce);
68 		if (rc)
69 			panic("PCI_DMA: HvCallXm_setTce failed, Rc: 0x%llx\n",
70 					rc);
71 		index++;
72 		uaddr += TCE_PAGE_SIZE;
73 	}
74 	return 0;
75 }
76 
tce_free_iSeries(struct iommu_table * tbl,long index,long npages)77 static void tce_free_iSeries(struct iommu_table *tbl, long index, long npages)
78 {
79 	u64 rc;
80 
81 	while (npages--) {
82 		rc = HvCallXm_setTce((u64)tbl->it_index, (u64)index, 0);
83 		if (rc)
84 			panic("PCI_DMA: HvCallXm_setTce failed, Rc: 0x%llx\n",
85 					rc);
86 		index++;
87 	}
88 }
89 
90 /*
91  * Structure passed to HvCallXm_getTceTableParms
92  */
93 struct iommu_table_cb {
94 	unsigned long	itc_busno;	/* Bus number for this tce table */
95 	unsigned long	itc_start;	/* Will be NULL for secondary */
96 	unsigned long	itc_totalsize;	/* Size (in pages) of whole table */
97 	unsigned long	itc_offset;	/* Index into real tce table of the
98 					   start of our section */
99 	unsigned long	itc_size;	/* Size (in pages) of our section */
100 	unsigned long	itc_index;	/* Index of this tce table */
101 	unsigned short	itc_maxtables;	/* Max num of tables for partition */
102 	unsigned char	itc_virtbus;	/* Flag to indicate virtual bus */
103 	unsigned char	itc_slotno;	/* IOA Tce Slot Index */
104 	unsigned char	itc_rsvd[4];
105 };
106 
107 /*
108  * Call Hv with the architected data structure to get TCE table info.
109  * info. Put the returned data into the Linux representation of the
110  * TCE table data.
111  * The Hardware Tce table comes in three flavors.
112  * 1. TCE table shared between Buses.
113  * 2. TCE table per Bus.
114  * 3. TCE Table per IOA.
115  */
iommu_table_getparms_iSeries(unsigned long busno,unsigned char slotno,unsigned char virtbus,struct iommu_table * tbl)116 void iommu_table_getparms_iSeries(unsigned long busno,
117 				  unsigned char slotno,
118 				  unsigned char virtbus,
119 				  struct iommu_table* tbl)
120 {
121 	struct iommu_table_cb *parms;
122 
123 	parms = kzalloc(sizeof(*parms), GFP_KERNEL);
124 	if (parms == NULL)
125 		panic("PCI_DMA: TCE Table Allocation failed.");
126 
127 	parms->itc_busno = busno;
128 	parms->itc_slotno = slotno;
129 	parms->itc_virtbus = virtbus;
130 
131 	HvCallXm_getTceTableParms(iseries_hv_addr(parms));
132 
133 	if (parms->itc_size == 0)
134 		panic("PCI_DMA: parms->size is zero, parms is 0x%p", parms);
135 
136 	/* itc_size is in pages worth of table, it_size is in # of entries */
137 	tbl->it_size = (parms->itc_size * TCE_PAGE_SIZE) / TCE_ENTRY_SIZE;
138 	tbl->it_busno = parms->itc_busno;
139 	tbl->it_offset = parms->itc_offset;
140 	tbl->it_index = parms->itc_index;
141 	tbl->it_blocksize = 1;
142 	tbl->it_type = virtbus ? TCE_VB : TCE_PCI;
143 
144 	kfree(parms);
145 }
146 
147 
148 #ifdef CONFIG_PCI
149 /*
150  * This function compares the known tables to find an iommu_table
151  * that has already been built for hardware TCEs.
152  */
iommu_table_find(struct iommu_table * tbl)153 static struct iommu_table *iommu_table_find(struct iommu_table * tbl)
154 {
155 	struct device_node *node;
156 
157 	for (node = NULL; (node = of_find_all_nodes(node)); ) {
158 		struct pci_dn *pdn = PCI_DN(node);
159 		struct iommu_table *it;
160 
161 		if (pdn == NULL)
162 			continue;
163 		it = pdn->iommu_table;
164 		if ((it != NULL) &&
165 		    (it->it_type == TCE_PCI) &&
166 		    (it->it_offset == tbl->it_offset) &&
167 		    (it->it_index == tbl->it_index) &&
168 		    (it->it_size == tbl->it_size)) {
169 			of_node_put(node);
170 			return it;
171 		}
172 	}
173 	return NULL;
174 }
175 
176 
iommu_devnode_init_iSeries(struct pci_dev * pdev,struct device_node * dn)177 void iommu_devnode_init_iSeries(struct pci_dev *pdev, struct device_node *dn)
178 {
179 	struct iommu_table *tbl;
180 	struct pci_dn *pdn = PCI_DN(dn);
181 	const u32 *lsn = of_get_property(dn, "linux,logical-slot-number", NULL);
182 
183 	BUG_ON(lsn == NULL);
184 
185 	tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
186 
187 	iommu_table_getparms_iSeries(pdn->busno, *lsn, 0, tbl);
188 
189 	/* Look for existing tce table */
190 	pdn->iommu_table = iommu_table_find(tbl);
191 	if (pdn->iommu_table == NULL)
192 		pdn->iommu_table = iommu_init_table(tbl, -1);
193 	else
194 		kfree(tbl);
195 	pdev->dev.archdata.dma_data = pdn->iommu_table;
196 }
197 #endif
198 
199 static struct iommu_table veth_iommu_table;
200 static struct iommu_table vio_iommu_table;
201 
iseries_hv_alloc(size_t size,dma_addr_t * dma_handle,gfp_t flag)202 void *iseries_hv_alloc(size_t size, dma_addr_t *dma_handle, gfp_t flag)
203 {
204 	return iommu_alloc_coherent(NULL, &vio_iommu_table, size, dma_handle,
205 				DMA_32BIT_MASK, flag, -1);
206 }
207 EXPORT_SYMBOL_GPL(iseries_hv_alloc);
208 
iseries_hv_free(size_t size,void * vaddr,dma_addr_t dma_handle)209 void iseries_hv_free(size_t size, void *vaddr, dma_addr_t dma_handle)
210 {
211 	iommu_free_coherent(&vio_iommu_table, size, vaddr, dma_handle);
212 }
213 EXPORT_SYMBOL_GPL(iseries_hv_free);
214 
iseries_hv_map(void * vaddr,size_t size,enum dma_data_direction direction)215 dma_addr_t iseries_hv_map(void *vaddr, size_t size,
216 			enum dma_data_direction direction)
217 {
218 	return iommu_map_page(NULL, &vio_iommu_table, virt_to_page(vaddr),
219 			      (unsigned long)vaddr % PAGE_SIZE, size,
220 			      DMA_32BIT_MASK, direction, NULL);
221 }
222 
iseries_hv_unmap(dma_addr_t dma_handle,size_t size,enum dma_data_direction direction)223 void iseries_hv_unmap(dma_addr_t dma_handle, size_t size,
224 			enum dma_data_direction direction)
225 {
226 	iommu_unmap_page(&vio_iommu_table, dma_handle, size, direction, NULL);
227 }
228 
iommu_vio_init(void)229 void __init iommu_vio_init(void)
230 {
231 	iommu_table_getparms_iSeries(255, 0, 0xff, &veth_iommu_table);
232 	veth_iommu_table.it_size /= 2;
233 	vio_iommu_table = veth_iommu_table;
234 	vio_iommu_table.it_offset += veth_iommu_table.it_size;
235 
236 	if (!iommu_init_table(&veth_iommu_table, -1))
237 		printk("Virtual Bus VETH TCE table failed.\n");
238 	if (!iommu_init_table(&vio_iommu_table, -1))
239 		printk("Virtual Bus VIO TCE table failed.\n");
240 }
241 
vio_build_iommu_table_iseries(struct vio_dev * dev)242 struct iommu_table *vio_build_iommu_table_iseries(struct vio_dev *dev)
243 {
244 	if (strcmp(dev->type, "network") == 0)
245 		return &veth_iommu_table;
246 	return &vio_iommu_table;
247 }
248 
iommu_init_early_iSeries(void)249 void iommu_init_early_iSeries(void)
250 {
251 	ppc_md.tce_build = tce_build_iSeries;
252 	ppc_md.tce_free  = tce_free_iSeries;
253 
254 	set_pci_dma_ops(&dma_iommu_ops);
255 }
256