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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * DMA memory management for framework level HCD code (hc_driver) | |
3 | * | |
4 | * This implementation plugs in through generic "usb_bus" level methods, | |
5 | * and should work with all USB controllers, regardles of bus type. | |
6 | */ | |
7 | ||
8 | #include <linux/config.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/mm.h> | |
14 | #include <asm/io.h> | |
15 | #include <asm/scatterlist.h> | |
16 | #include <linux/dma-mapping.h> | |
17 | #include <linux/dmapool.h> | |
1da177e4 LT |
18 | #include <linux/usb.h> |
19 | #include "hcd.h" | |
20 | ||
21 | ||
22 | /* | |
23 | * DMA-Coherent Buffers | |
24 | */ | |
25 | ||
26 | /* FIXME tune these based on pool statistics ... */ | |
27 | static const size_t pool_max [HCD_BUFFER_POOLS] = { | |
28 | /* platforms without dma-friendly caches might need to | |
29 | * prevent cacheline sharing... | |
30 | */ | |
31 | 32, | |
32 | 128, | |
33 | 512, | |
34 | PAGE_SIZE / 2 | |
35 | /* bigger --> allocate pages */ | |
36 | }; | |
37 | ||
38 | ||
39 | /* SETUP primitives */ | |
40 | ||
41 | /** | |
42 | * hcd_buffer_create - initialize buffer pools | |
43 | * @hcd: the bus whose buffer pools are to be initialized | |
44 | * Context: !in_interrupt() | |
45 | * | |
46 | * Call this as part of initializing a host controller that uses the dma | |
47 | * memory allocators. It initializes some pools of dma-coherent memory that | |
48 | * will be shared by all drivers using that controller, or returns a negative | |
49 | * errno value on error. | |
50 | * | |
51 | * Call hcd_buffer_destroy() to clean up after using those pools. | |
52 | */ | |
53 | int hcd_buffer_create (struct usb_hcd *hcd) | |
54 | { | |
55 | char name [16]; | |
56 | int i, size; | |
57 | ||
bd39b7f1 CH |
58 | if (!hcd->self.controller->dma_mask) |
59 | return 0; | |
60 | ||
1da177e4 LT |
61 | for (i = 0; i < HCD_BUFFER_POOLS; i++) { |
62 | if (!(size = pool_max [i])) | |
63 | continue; | |
64 | snprintf (name, sizeof name, "buffer-%d", size); | |
65 | hcd->pool [i] = dma_pool_create (name, hcd->self.controller, | |
66 | size, size, 0); | |
67 | if (!hcd->pool [i]) { | |
68 | hcd_buffer_destroy (hcd); | |
69 | return -ENOMEM; | |
70 | } | |
71 | } | |
72 | return 0; | |
73 | } | |
74 | ||
75 | ||
76 | /** | |
77 | * hcd_buffer_destroy - deallocate buffer pools | |
78 | * @hcd: the bus whose buffer pools are to be destroyed | |
79 | * Context: !in_interrupt() | |
80 | * | |
81 | * This frees the buffer pools created by hcd_buffer_create(). | |
82 | */ | |
83 | void hcd_buffer_destroy (struct usb_hcd *hcd) | |
84 | { | |
85 | int i; | |
86 | ||
87 | for (i = 0; i < HCD_BUFFER_POOLS; i++) { | |
88 | struct dma_pool *pool = hcd->pool [i]; | |
89 | if (pool) { | |
90 | dma_pool_destroy (pool); | |
91 | hcd->pool[i] = NULL; | |
92 | } | |
93 | } | |
94 | } | |
95 | ||
96 | ||
97 | /* sometimes alloc/free could use kmalloc with SLAB_DMA, for | |
98 | * better sharing and to leverage mm/slab.c intelligence. | |
99 | */ | |
100 | ||
101 | void *hcd_buffer_alloc ( | |
102 | struct usb_bus *bus, | |
103 | size_t size, | |
55016f10 | 104 | gfp_t mem_flags, |
1da177e4 LT |
105 | dma_addr_t *dma |
106 | ) | |
107 | { | |
108 | struct usb_hcd *hcd = bus->hcpriv; | |
109 | int i; | |
110 | ||
111 | /* some USB hosts just use PIO */ | |
112 | if (!bus->controller->dma_mask) { | |
113 | *dma = ~(dma_addr_t) 0; | |
114 | return kmalloc (size, mem_flags); | |
115 | } | |
116 | ||
117 | for (i = 0; i < HCD_BUFFER_POOLS; i++) { | |
118 | if (size <= pool_max [i]) | |
119 | return dma_pool_alloc (hcd->pool [i], mem_flags, dma); | |
120 | } | |
121 | return dma_alloc_coherent (hcd->self.controller, size, dma, 0); | |
122 | } | |
123 | ||
124 | void hcd_buffer_free ( | |
125 | struct usb_bus *bus, | |
126 | size_t size, | |
127 | void *addr, | |
128 | dma_addr_t dma | |
129 | ) | |
130 | { | |
131 | struct usb_hcd *hcd = bus->hcpriv; | |
132 | int i; | |
133 | ||
134 | if (!addr) | |
135 | return; | |
136 | ||
137 | if (!bus->controller->dma_mask) { | |
138 | kfree (addr); | |
139 | return; | |
140 | } | |
141 | ||
142 | for (i = 0; i < HCD_BUFFER_POOLS; i++) { | |
143 | if (size <= pool_max [i]) { | |
144 | dma_pool_free (hcd->pool [i], addr, dma); | |
145 | return; | |
146 | } | |
147 | } | |
148 | dma_free_coherent (hcd->self.controller, size, addr, dma); | |
149 | } |