xref: /openbmc/linux/drivers/usb/host/ohci-mem.c (revision 293d5b43)
1 /*
2  * OHCI HCD (Host Controller Driver) for USB.
3  *
4  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
5  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
6  *
7  * This file is licenced under the GPL.
8  */
9 
10 /*-------------------------------------------------------------------------*/
11 
12 /*
13  * OHCI deals with three types of memory:
14  *	- data used only by the HCD ... kmalloc is fine
15  *	- async and periodic schedules, shared by HC and HCD ... these
16  *	  need to use dma_pool or dma_alloc_coherent
17  *	- driver buffers, read/written by HC ... the hcd glue or the
18  *	  device driver provides us with dma addresses
19  *
20  * There's also "register" data, which is memory mapped.
21  * No memory seen by this driver (or any HCD) may be paged out.
22  */
23 
24 /*-------------------------------------------------------------------------*/
25 
26 static void ohci_hcd_init (struct ohci_hcd *ohci)
27 {
28 	ohci->next_statechange = jiffies;
29 	spin_lock_init (&ohci->lock);
30 	INIT_LIST_HEAD (&ohci->pending);
31 	INIT_LIST_HEAD(&ohci->eds_in_use);
32 }
33 
34 /*-------------------------------------------------------------------------*/
35 
36 static int ohci_mem_init (struct ohci_hcd *ohci)
37 {
38 	ohci->td_cache = dma_pool_create ("ohci_td",
39 		ohci_to_hcd(ohci)->self.controller,
40 		sizeof (struct td),
41 		32 /* byte alignment */,
42 		0 /* no page-crossing issues */);
43 	if (!ohci->td_cache)
44 		return -ENOMEM;
45 	ohci->ed_cache = dma_pool_create ("ohci_ed",
46 		ohci_to_hcd(ohci)->self.controller,
47 		sizeof (struct ed),
48 		16 /* byte alignment */,
49 		0 /* no page-crossing issues */);
50 	if (!ohci->ed_cache) {
51 		dma_pool_destroy (ohci->td_cache);
52 		return -ENOMEM;
53 	}
54 	return 0;
55 }
56 
57 static void ohci_mem_cleanup (struct ohci_hcd *ohci)
58 {
59 	if (ohci->td_cache) {
60 		dma_pool_destroy (ohci->td_cache);
61 		ohci->td_cache = NULL;
62 	}
63 	if (ohci->ed_cache) {
64 		dma_pool_destroy (ohci->ed_cache);
65 		ohci->ed_cache = NULL;
66 	}
67 }
68 
69 /*-------------------------------------------------------------------------*/
70 
71 /* ohci "done list" processing needs this mapping */
72 static inline struct td *
73 dma_to_td (struct ohci_hcd *hc, dma_addr_t td_dma)
74 {
75 	struct td *td;
76 
77 	td_dma &= TD_MASK;
78 	td = hc->td_hash [TD_HASH_FUNC(td_dma)];
79 	while (td && td->td_dma != td_dma)
80 		td = td->td_hash;
81 	return td;
82 }
83 
84 /* TDs ... */
85 static struct td *
86 td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
87 {
88 	dma_addr_t	dma;
89 	struct td	*td;
90 
91 	td = dma_pool_alloc (hc->td_cache, mem_flags, &dma);
92 	if (td) {
93 		/* in case hc fetches it, make it look dead */
94 		memset (td, 0, sizeof *td);
95 		td->hwNextTD = cpu_to_hc32 (hc, dma);
96 		td->td_dma = dma;
97 		/* hashed in td_fill */
98 	}
99 	return td;
100 }
101 
102 static void
103 td_free (struct ohci_hcd *hc, struct td *td)
104 {
105 	struct td	**prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];
106 
107 	while (*prev && *prev != td)
108 		prev = &(*prev)->td_hash;
109 	if (*prev)
110 		*prev = td->td_hash;
111 	else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
112 		ohci_dbg (hc, "no hash for td %p\n", td);
113 	dma_pool_free (hc->td_cache, td, td->td_dma);
114 }
115 
116 /*-------------------------------------------------------------------------*/
117 
118 /* EDs ... */
119 static struct ed *
120 ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
121 {
122 	dma_addr_t	dma;
123 	struct ed	*ed;
124 
125 	ed = dma_pool_alloc (hc->ed_cache, mem_flags, &dma);
126 	if (ed) {
127 		memset (ed, 0, sizeof (*ed));
128 		INIT_LIST_HEAD (&ed->td_list);
129 		ed->dma = dma;
130 	}
131 	return ed;
132 }
133 
134 static void
135 ed_free (struct ohci_hcd *hc, struct ed *ed)
136 {
137 	dma_pool_free (hc->ed_cache, ed, ed->dma);
138 }
139 
140