1 /*
2 * ccio-rm-dma.c:
3 * DMA management routines for first generation cache-coherent machines.
4 * "Real Mode" operation refers to U2/Uturn chip operation. The chip
5 * can perform coherency checks w/o using the I/O MMU. That's all we
6 * need until support for more than 4GB phys mem is needed.
7 *
8 * This is the trivial case - basically what x86 does.
9 *
10 * Drawbacks of using Real Mode are:
11 * o outbound DMA is slower since one isn't using the prefetching
12 * U2 can do for outbound DMA.
13 * o Ability to do scatter/gather in HW is also lost.
14 * o only known to work with PCX-W processor. (eg C360)
15 * (PCX-U/U+ are not coherent with U2 in real mode.)
16 *
17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 *
24 * Original version/author:
25 * CVSROOT=:pserver:anonymous@198.186.203.37:/cvsroot/linux-parisc
26 * cvs -z3 co linux/arch/parisc/kernel/dma-rm.c
27 *
28 * (C) Copyright 2000 Philipp Rumpf <prumpf@tux.org>
29 *
30 *
31 * Adopted for The Puffin Group's parisc-linux port by Grant Grundler.
32 * (C) Copyright 2000 Grant Grundler <grundler@puffin.external.hp.com>
33 *
34 */
35
36 #include <linux/types.h>
37 #include <linux/init.h>
38 #include <linux/mm.h>
39 #include <linux/string.h>
40 #include <linux/pci.h>
41
42 #include <asm/uaccess.h>
43
44 #include <asm/io.h>
45 #include <asm/hardware.h>
46 #include <asm/page.h>
47
48 /* Only chose "ccio" since that's what HP-UX calls it....
49 ** Make it easier for folks to migrate from one to the other :^)
50 */
51 #define MODULE_NAME "ccio"
52
53 #define U2_IOA_RUNWAY 0x580
54 #define U2_BC_GSC 0x501
55 #define UTURN_IOA_RUNWAY 0x581
56 #define UTURN_BC_GSC 0x502
57
58 #define IS_U2(id) ( \
59 (((id)->hw_type == HPHW_IOA) && ((id)->hversion == U2_IOA_RUNWAY)) || \
60 (((id)->hw_type == HPHW_BCPORT) && ((id)->hversion == U2_BC_GSC)) \
61 )
62
63 #define IS_UTURN(id) ( \
64 (((id)->hw_type == HPHW_IOA) && ((id)->hversion == UTURN_IOA_RUNWAY)) || \
65 (((id)->hw_type == HPHW_BCPORT) && ((id)->hversion == UTURN_BC_GSC)) \
66 )
67
68 static int ccio_dma_supported( struct pci_dev *dev, u64 mask)
69 {
70 if (dev == NULL) {
71 printk(KERN_ERR MODULE_NAME ": EISA/ISA/et al not supported\n");
72 BUG();
73 return(0);
74 }
75
76 /* only support 32-bit devices (ie PCI/GSC) */
77 return((int) (mask >= 0xffffffffUL));
78 }
79
80
81 static void *ccio_alloc_consistent(struct pci_dev *dev, size_t size,
82 dma_addr_t *handle)
83 {
84 void *ret;
85
86 ret = (void *)__get_free_pages(GFP_ATOMIC, get_order(size));
87
88 if (ret != NULL) {
89 memset(ret, 0, size);
90 *handle = virt_to_phys(ret);
91 }
92 return ret;
93 }
94
95 static void ccio_free_consistent(struct pci_dev *dev, size_t size,
96 void *vaddr, dma_addr_t handle)
97 {
98 free_pages((unsigned long)vaddr, get_order(size));
99 }
100
101 static dma_addr_t ccio_map_single(struct pci_dev *dev, void *ptr, size_t size,
102 int direction)
103 {
104 return virt_to_phys(ptr);
105 }
106
107 static void ccio_unmap_single(struct pci_dev *dev, dma_addr_t dma_addr,
108 size_t size, int direction)
109 {
110 /* Nothing to do */
111 }
112
113
114 static int ccio_map_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
115 {
116 int tmp = nents;
117
118 /* KISS: map each buffer separately. */
119 while (nents) {
120 sg_dma_address(sglist) = ccio_map_single(dev, sglist->address, sglist->length, direction);
121 sg_dma_len(sglist) = sglist->length;
122 nents--;
123 sglist++;
124 }
125
126 return tmp;
127 }
128
129
130 static void ccio_unmap_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
131 {
132 #if 0
133 while (nents) {
134 ccio_unmap_single(dev, sg_dma_address(sglist), sg_dma_len(sglist), direction);
135 nents--;
136 sglist++;
137 }
138 return;
139 #else
140 /* Do nothing (copied from current ccio_unmap_single() :^) */
141 #endif
142 }
143
144
145 static struct pci_dma_ops ccio_ops = {
146 ccio_dma_supported,
147 ccio_alloc_consistent,
148 ccio_free_consistent,
149 ccio_map_single,
150 ccio_unmap_single,
151 ccio_map_sg,
152 ccio_unmap_sg,
153 NULL, /* dma_sync_single_for_cpu : NOP for U2 */
154 NULL, /* dma_sync_single_for_device : NOP for U2 */
155 NULL, /* dma_sync_sg_for_cpu : ditto */
156 NULL, /* dma_sync_sg_for_device : ditto */
157 };
158
159
160 /*
161 ** Determine if u2 should claim this chip (return 0) or not (return 1).
162 ** If so, initialize the chip and tell other partners in crime they
163 ** have work to do.
164 */
165 static int
166 ccio_probe(struct parisc_device *dev)
167 {
168 printk(KERN_INFO "%s found %s at 0x%lx\n", MODULE_NAME,
169 dev->id.hversion == U2_BC_GSC ? "U2" : "UTurn",
170 dev->hpa.start);
171
172 /*
173 ** FIXME - should check U2 registers to verify it's really running
174 ** in "Real Mode".
175 */
176
177 #if 0
178 /* will need this for "Virtual Mode" operation */
179 ccio_hw_init(ccio_dev);
180 ccio_common_init(ccio_dev);
181 #endif
182 hppa_dma_ops = &ccio_ops;
183 return 0;
184 }
185
186 static struct parisc_device_id ccio_tbl[] = {
187 { HPHW_BCPORT, HVERSION_REV_ANY_ID, U2_BC_GSC, 0xc },
188 { HPHW_BCPORT, HVERSION_REV_ANY_ID, UTURN_BC_GSC, 0xc },
189 { 0, }
190 };
191
192 static struct parisc_driver ccio_driver = {
193 .name = "U2/Uturn",
194 .id_table = ccio_tbl,
195 .probe = ccio_probe,
196 };
197
198 void __init ccio_init(void)
199 {
200 register_parisc_driver(&ccio_driver);
201 }
202
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