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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 | /* * DMA memory management for framework level HCD code (hc_driver) * * This implementation plugs in through generic "usb_bus" level methods, * and should work with all USB controllers, regardless of bus type. */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/device.h> #include <linux/mm.h> #include <linux/io.h> #include <linux/dma-mapping.h> #include <linux/dmapool.h> #include <linux/usb.h> #include <linux/usb/hcd.h> /* * DMA-Coherent Buffers */ /* FIXME tune these based on pool statistics ... */ static size_t pool_max[HCD_BUFFER_POOLS] = { 32, 128, 512, 2048, }; void __init usb_init_pool_max(void) { /* * The pool_max values must never be smaller than * ARCH_KMALLOC_MINALIGN. */ if (ARCH_KMALLOC_MINALIGN <= 32) ; /* Original value is okay */ else if (ARCH_KMALLOC_MINALIGN <= 64) pool_max[0] = 64; else if (ARCH_KMALLOC_MINALIGN <= 128) pool_max[0] = 0; /* Don't use this pool */ else BUILD_BUG(); /* We don't allow this */ } /* SETUP primitives */ /** * hcd_buffer_create - initialize buffer pools * @hcd: the bus whose buffer pools are to be initialized * Context: !in_interrupt() * * Call this as part of initializing a host controller that uses the dma * memory allocators. It initializes some pools of dma-coherent memory that * will be shared by all drivers using that controller. * * Call hcd_buffer_destroy() to clean up after using those pools. * * Return: 0 if successful. A negative errno value otherwise. */ int hcd_buffer_create(struct usb_hcd *hcd) { char name[16]; int i, size; if (!hcd->self.controller->dma_mask && !(hcd->driver->flags & HCD_LOCAL_MEM)) return 0; for (i = 0; i < HCD_BUFFER_POOLS; i++) { size = pool_max[i]; if (!size) continue; snprintf(name, sizeof name, "buffer-%d", size); hcd->pool[i] = dma_pool_create(name, hcd->self.controller, size, size, 0); if (!hcd->pool[i]) { hcd_buffer_destroy(hcd); return -ENOMEM; } } return 0; } /** * hcd_buffer_destroy - deallocate buffer pools * @hcd: the bus whose buffer pools are to be destroyed * Context: !in_interrupt() * * This frees the buffer pools created by hcd_buffer_create(). */ void hcd_buffer_destroy(struct usb_hcd *hcd) { int i; for (i = 0; i < HCD_BUFFER_POOLS; i++) { struct dma_pool *pool = hcd->pool[i]; if (pool) { dma_pool_destroy(pool); hcd->pool[i] = NULL; } } } /* sometimes alloc/free could use kmalloc with GFP_DMA, for * better sharing and to leverage mm/slab.c intelligence. */ void *hcd_buffer_alloc( struct usb_bus *bus, size_t size, gfp_t mem_flags, dma_addr_t *dma ) { struct usb_hcd *hcd = bus_to_hcd(bus); int i; /* some USB hosts just use PIO */ if (!bus->controller->dma_mask && !(hcd->driver->flags & HCD_LOCAL_MEM)) { *dma = ~(dma_addr_t) 0; return kmalloc(size, mem_flags); } for (i = 0; i < HCD_BUFFER_POOLS; i++) { if (size <= pool_max[i]) return dma_pool_alloc(hcd->pool[i], mem_flags, dma); } return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags); } void hcd_buffer_free( struct usb_bus *bus, size_t size, void *addr, dma_addr_t dma ) { struct usb_hcd *hcd = bus_to_hcd(bus); int i; if (!addr) return; if (!bus->controller->dma_mask && !(hcd->driver->flags & HCD_LOCAL_MEM)) { kfree(addr); return; } for (i = 0; i < HCD_BUFFER_POOLS; i++) { if (size <= pool_max[i]) { dma_pool_free(hcd->pool[i], addr, dma); return; } } dma_free_coherent(hcd->self.controller, size, addr, dma); } |