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
68static 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
81static 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
95static 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
101static 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
107static 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
114static 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
130static void ccio_unmap_sg(struct pci_dev *dev, struct scatterlist *sglist, int nents, int direction)
131{
132	/* Do nothing (copied from current ccio_unmap_single()  :^) */
133}
134
135
136static struct pci_dma_ops ccio_ops = {
137	ccio_dma_supported,
138	ccio_alloc_consistent,
139	ccio_free_consistent,
140	ccio_map_single,
141	ccio_unmap_single,
142	ccio_map_sg,
143	ccio_unmap_sg,
144	NULL,                   /* dma_sync_single_for_cpu : NOP for U2 */
145	NULL,                   /* dma_sync_single_for_device : NOP for U2 */
146	NULL,                   /* dma_sync_sg_for_cpu     : ditto */
147	NULL,                   /* dma_sync_sg_for_device     : ditto */
148};
149
150
151/*
152** Determine if u2 should claim this chip (return 0) or not (return 1).
153** If so, initialize the chip and tell other partners in crime they
154** have work to do.
155*/
156static int
157ccio_probe(struct parisc_device *dev)
158{
159	printk(KERN_INFO "%s found %s at 0x%lx\n", MODULE_NAME,
160			dev->id.hversion == U2_BC_GSC ? "U2" : "UTurn",
161			dev->hpa.start);
162
163
164	hppa_dma_ops = &ccio_ops;
165	return 0;
166}
167
168static struct parisc_device_id ccio_tbl[] = {
169	{ HPHW_BCPORT, HVERSION_REV_ANY_ID, U2_BC_GSC, 0xc },
170	{ HPHW_BCPORT, HVERSION_REV_ANY_ID, UTURN_BC_GSC, 0xc },
171	{ 0, }
172};
173
174static struct parisc_driver ccio_driver = {
175	.name =		"U2/Uturn",
176	.id_table =	ccio_tbl,
177	.probe =	ccio_probe,
178};
179
180void __init ccio_init(void)
181{
182	register_parisc_driver(&ccio_driver);
183}
184