Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/usb.h> |
| 18 | #include "hcd.h" |
| 19 | |
| 20 | |
| 21 | /* |
| 22 | * DMA-Coherent Buffers |
| 23 | */ |
| 24 | |
| 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... |
| 29 | */ |
| 30 | 32, |
| 31 | 128, |
| 32 | 512, |
| 33 | PAGE_SIZE / 2 |
| 34 | /* bigger --> allocate pages */ |
| 35 | }; |
| 36 | |
| 37 | |
| 38 | /* SETUP primitives */ |
| 39 | |
| 40 | /** |
| 41 | * hcd_buffer_create - initialize buffer pools |
| 42 | * @hcd: the bus whose buffer pools are to be initialized |
| 43 | * Context: !in_interrupt() |
| 44 | * |
| 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. |
| 49 | * |
| 50 | * Call hcd_buffer_destroy() to clean up after using those pools. |
| 51 | */ |
| 52 | int hcd_buffer_create (struct usb_hcd *hcd) |
| 53 | { |
| 54 | char name [16]; |
| 55 | int i, size; |
| 56 | |
Chris Humbert | bd39b7f | 2005-11-28 09:29:23 -0800 | [diff] [blame] | 57 | if (!hcd->self.controller->dma_mask) |
| 58 | return 0; |
| 59 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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; |
| 69 | } |
| 70 | } |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | |
| 75 | /** |
| 76 | * hcd_buffer_destroy - deallocate buffer pools |
| 77 | * @hcd: the bus whose buffer pools are to be destroyed |
| 78 | * Context: !in_interrupt() |
| 79 | * |
| 80 | * This frees the buffer pools created by hcd_buffer_create(). |
| 81 | */ |
| 82 | void hcd_buffer_destroy (struct usb_hcd *hcd) |
| 83 | { |
| 84 | int i; |
| 85 | |
| 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; |
| 91 | } |
| 92 | } |
| 93 | } |
| 94 | |
| 95 | |
Christoph Lameter | 441e143 | 2006-12-06 20:33:19 -0800 | [diff] [blame] | 96 | /* sometimes alloc/free could use kmalloc with GFP_DMA, for |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | * better sharing and to leverage mm/slab.c intelligence. |
| 98 | */ |
| 99 | |
| 100 | void *hcd_buffer_alloc ( |
| 101 | struct usb_bus *bus, |
| 102 | size_t size, |
Al Viro | 55016f1 | 2005-10-21 03:21:58 -0400 | [diff] [blame] | 103 | gfp_t mem_flags, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | dma_addr_t *dma |
| 105 | ) |
| 106 | { |
Alan Stern | 1720058 | 2006-08-30 11:32:52 -0400 | [diff] [blame] | 107 | struct usb_hcd *hcd = bus_to_hcd(bus); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | int i; |
| 109 | |
| 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); |
| 114 | } |
| 115 | |
| 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); |
| 119 | } |
| 120 | return dma_alloc_coherent (hcd->self.controller, size, dma, 0); |
| 121 | } |
| 122 | |
| 123 | void hcd_buffer_free ( |
| 124 | struct usb_bus *bus, |
| 125 | size_t size, |
| 126 | void *addr, |
| 127 | dma_addr_t dma |
| 128 | ) |
| 129 | { |
Alan Stern | 1720058 | 2006-08-30 11:32:52 -0400 | [diff] [blame] | 130 | struct usb_hcd *hcd = bus_to_hcd(bus); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 131 | int i; |
| 132 | |
| 133 | if (!addr) |
| 134 | return; |
| 135 | |
| 136 | if (!bus->controller->dma_mask) { |
| 137 | kfree (addr); |
| 138 | return; |
| 139 | } |
| 140 | |
| 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; |
| 145 | } |
| 146 | } |
| 147 | dma_free_coherent (hcd->self.controller, size, addr, dma); |
| 148 | } |