xref: /openbmc/linux/drivers/usb/host/ohci-mem.c (revision ba61bb17) 
1 // SPDX-License-Identifier: GPL-1.0+
2 /*
3  * OHCI HCD (Host Controller Driver) for USB.
4  *
5  * (C) Copyright 1999 Roman Weissgaerber <weissg@vienna.at>
6  * (C) Copyright 2000-2002 David Brownell <dbrownell@users.sourceforge.net>
7  *
8  * This file is licenced under the GPL.
9  */
10 
11 /*-------------------------------------------------------------------------*/
12 
13 /*
14  * OHCI deals with three types of memory:
15  *	- data used only by the HCD ... kmalloc is fine
16  *	- async and periodic schedules, shared by HC and HCD ... these
17  *	  need to use dma_pool or dma_alloc_coherent
18  *	- driver buffers, read/written by HC ... the hcd glue or the
19  *	  device driver provides us with dma addresses
20  *
21  * There's also "register" data, which is memory mapped.
22  * No memory seen by this driver (or any HCD) may be paged out.
23  */
24 
25 /*-------------------------------------------------------------------------*/
26 
27 static void ohci_hcd_init (struct ohci_hcd *ohci)
28 {
29 	ohci->next_statechange = jiffies;
30 	spin_lock_init (&ohci->lock);
31 	INIT_LIST_HEAD (&ohci->pending);
32 	INIT_LIST_HEAD(&ohci->eds_in_use);
33 }
34 
35 /*-------------------------------------------------------------------------*/
36 
37 static int ohci_mem_init (struct ohci_hcd *ohci)
38 {
39 	ohci->td_cache = dma_pool_create ("ohci_td",
40 		ohci_to_hcd(ohci)->self.controller,
41 		sizeof (struct td),
42 		32 /* byte alignment */,
43 		0 /* no page-crossing issues */);
44 	if (!ohci->td_cache)
45 		return -ENOMEM;
46 	ohci->ed_cache = dma_pool_create ("ohci_ed",
47 		ohci_to_hcd(ohci)->self.controller,
48 		sizeof (struct ed),
49 		16 /* byte alignment */,
50 		0 /* no page-crossing issues */);
51 	if (!ohci->ed_cache) {
52 		dma_pool_destroy (ohci->td_cache);
53 		return -ENOMEM;
54 	}
55 	return 0;
56 }
57 
58 static void ohci_mem_cleanup (struct ohci_hcd *ohci)
59 {
60 	if (ohci->td_cache) {
61 		dma_pool_destroy (ohci->td_cache);
62 		ohci->td_cache = NULL;
63 	}
64 	if (ohci->ed_cache) {
65 		dma_pool_destroy (ohci->ed_cache);
66 		ohci->ed_cache = NULL;
67 	}
68 }
69 
70 /*-------------------------------------------------------------------------*/
71 
72 /* ohci "done list" processing needs this mapping */
73 static inline struct td *
74 dma_to_td (struct ohci_hcd *hc, dma_addr_t td_dma)
75 {
76 	struct td *td;
77 
78 	td_dma &= TD_MASK;
79 	td = hc->td_hash [TD_HASH_FUNC(td_dma)];
80 	while (td && td->td_dma != td_dma)
81 		td = td->td_hash;
82 	return td;
83 }
84 
85 /* TDs ... */
86 static struct td *
87 td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
88 {
89 	dma_addr_t	dma;
90 	struct td	*td;
91 
92 	td = dma_pool_zalloc (hc->td_cache, mem_flags, &dma);
93 	if (td) {
94 		/* in case hc fetches it, make it look dead */
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_zalloc (hc->ed_cache, mem_flags, &dma);
126 	if (ed) {
127 		INIT_LIST_HEAD (&ed->td_list);
128 		ed->dma = dma;
129 	}
130 	return ed;
131 }
132 
133 static void
134 ed_free (struct ohci_hcd *hc, struct ed *ed)
135 {
136 	dma_pool_free (hc->ed_cache, ed, ed->dma);
137 }
138 
139