MOXA linux-2.6.x / linux-2.6.19-uc1 from UC-7110-LX-BOOTLOADER-1.9_VERSION-4.2.tgz
[linux-2.6.19-moxart.git] / drivers / usb / core / buffer.c
blob840442a25b6183844979b3c2f5fc58d3607fb7ac
1 /*
2 * DMA memory management for framework level HCD code (hc_driver)
4 * This implementation plugs in through generic "usb_bus" level methods,
5 * and should work with all USB controllers, regardles of bus type.
6 */
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/slab.h>
11 #include <linux/device.h>
12 #include <linux/mm.h>
13 #include <asm/io.h>
14 #include <asm/scatterlist.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/dmapool.h>
17 #include <linux/usb.h>
18 #include "hcd.h"
22 * DMA-Coherent Buffers
25 /* FIXME tune these based on pool statistics ... */
26 static const size_t pool_max [HCD_BUFFER_POOLS] = {
27 /* platforms without dma-friendly caches might need to
28 * prevent cacheline sharing...
30 32,
31 128,
32 512,
33 PAGE_SIZE / 2
34 /* bigger --> allocate pages */
38 /* SETUP primitives */
40 /**
41 * hcd_buffer_create - initialize buffer pools
42 * @hcd: the bus whose buffer pools are to be initialized
43 * Context: !in_interrupt()
45 * Call this as part of initializing a host controller that uses the dma
46 * memory allocators. It initializes some pools of dma-coherent memory that
47 * will be shared by all drivers using that controller, or returns a negative
48 * errno value on error.
50 * Call hcd_buffer_destroy() to clean up after using those pools.
52 int hcd_buffer_create (struct usb_hcd *hcd)
54 char name [16];
55 int i, size;
57 if (!hcd->self.controller->dma_mask)
58 return 0;
60 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
61 if (!(size = pool_max [i]))
62 continue;
63 snprintf (name, sizeof name, "buffer-%d", size);
64 hcd->pool [i] = dma_pool_create (name, hcd->self.controller,
65 size, size, 0);
66 if (!hcd->pool [i]) {
67 hcd_buffer_destroy (hcd);
68 return -ENOMEM;
71 return 0;
75 /**
76 * hcd_buffer_destroy - deallocate buffer pools
77 * @hcd: the bus whose buffer pools are to be destroyed
78 * Context: !in_interrupt()
80 * This frees the buffer pools created by hcd_buffer_create().
82 void hcd_buffer_destroy (struct usb_hcd *hcd)
84 int i;
86 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
87 struct dma_pool *pool = hcd->pool [i];
88 if (pool) {
89 dma_pool_destroy (pool);
90 hcd->pool[i] = NULL;
96 /* sometimes alloc/free could use kmalloc with SLAB_DMA, for
97 * better sharing and to leverage mm/slab.c intelligence.
100 void *hcd_buffer_alloc (
101 struct usb_bus *bus,
102 size_t size,
103 gfp_t mem_flags,
104 dma_addr_t *dma
107 struct usb_hcd *hcd = bus_to_hcd(bus);
108 int i;
110 /* some USB hosts just use PIO */
111 if (!bus->controller->dma_mask) {
112 *dma = ~(dma_addr_t) 0;
113 return kmalloc (size, mem_flags);
116 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
117 if (size <= pool_max [i])
118 return dma_pool_alloc (hcd->pool [i], mem_flags, dma);
120 return dma_alloc_coherent (hcd->self.controller, size, dma, 0);
123 void hcd_buffer_free (
124 struct usb_bus *bus,
125 size_t size,
126 void *addr,
127 dma_addr_t dma
130 struct usb_hcd *hcd = bus_to_hcd(bus);
131 int i;
133 if (!addr)
134 return;
136 if (!bus->controller->dma_mask) {
137 kfree (addr);
138 return;
141 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
142 if (size <= pool_max [i]) {
143 dma_pool_free (hcd->pool [i], addr, dma);
144 return;
147 dma_free_coherent (hcd->self.controller, size, addr, dma);