1a1c55580SChristian Lamparter /* 2a1c55580SChristian Lamparter * Copyright (c) 2009 Atheros Communications Inc. 3a1c55580SChristian Lamparter * 4a1c55580SChristian Lamparter * Permission to use, copy, modify, and/or distribute this software for any 5a1c55580SChristian Lamparter * purpose with or without fee is hereby granted, provided that the above 6a1c55580SChristian Lamparter * copyright notice and this permission notice appear in all copies. 7a1c55580SChristian Lamparter * 8a1c55580SChristian Lamparter * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 9a1c55580SChristian Lamparter * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 10a1c55580SChristian Lamparter * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 11a1c55580SChristian Lamparter * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 12a1c55580SChristian Lamparter * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 13a1c55580SChristian Lamparter * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 14a1c55580SChristian Lamparter * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 15a1c55580SChristian Lamparter */ 16a1c55580SChristian Lamparter 17a1c55580SChristian Lamparter #include <linux/kernel.h> 18a1c55580SChristian Lamparter #include <linux/module.h> 19a1c55580SChristian Lamparter 20d15dd3e5SLuis R. Rodriguez #include "ath.h" 21d15dd3e5SLuis R. Rodriguez 22a1c55580SChristian Lamparter MODULE_AUTHOR("Atheros Communications"); 23a1c55580SChristian Lamparter MODULE_DESCRIPTION("Shared library for Atheros wireless LAN cards."); 24a1c55580SChristian Lamparter MODULE_LICENSE("Dual BSD/GPL"); 25d15dd3e5SLuis R. Rodriguez 26d15dd3e5SLuis R. Rodriguez struct sk_buff *ath_rxbuf_alloc(struct ath_common *common, 27d15dd3e5SLuis R. Rodriguez u32 len, 28d15dd3e5SLuis R. Rodriguez gfp_t gfp_mask) 29d15dd3e5SLuis R. Rodriguez { 30d15dd3e5SLuis R. Rodriguez struct sk_buff *skb; 31d15dd3e5SLuis R. Rodriguez u32 off; 32d15dd3e5SLuis R. Rodriguez 33d15dd3e5SLuis R. Rodriguez /* 34d15dd3e5SLuis R. Rodriguez * Cache-line-align. This is important (for the 35d15dd3e5SLuis R. Rodriguez * 5210 at least) as not doing so causes bogus data 36d15dd3e5SLuis R. Rodriguez * in rx'd frames. 37d15dd3e5SLuis R. Rodriguez */ 38d15dd3e5SLuis R. Rodriguez 39d15dd3e5SLuis R. Rodriguez /* Note: the kernel can allocate a value greater than 40d15dd3e5SLuis R. Rodriguez * what we ask it to give us. We really only need 4 KB as that 41d15dd3e5SLuis R. Rodriguez * is this hardware supports and in fact we need at least 3849 42d15dd3e5SLuis R. Rodriguez * as that is the MAX AMSDU size this hardware supports. 43d15dd3e5SLuis R. Rodriguez * Unfortunately this means we may get 8 KB here from the 44d15dd3e5SLuis R. Rodriguez * kernel... and that is actually what is observed on some 45d15dd3e5SLuis R. Rodriguez * systems :( */ 46d15dd3e5SLuis R. Rodriguez skb = __dev_alloc_skb(len + common->cachelsz - 1, gfp_mask); 47d15dd3e5SLuis R. Rodriguez if (skb != NULL) { 48d15dd3e5SLuis R. Rodriguez off = ((unsigned long) skb->data) % common->cachelsz; 49d15dd3e5SLuis R. Rodriguez if (off != 0) 50d15dd3e5SLuis R. Rodriguez skb_reserve(skb, common->cachelsz - off); 51d15dd3e5SLuis R. Rodriguez } else { 52d15dd3e5SLuis R. Rodriguez printk(KERN_ERR "skbuff alloc of size %u failed\n", len); 53d15dd3e5SLuis R. Rodriguez return NULL; 54d15dd3e5SLuis R. Rodriguez } 55d15dd3e5SLuis R. Rodriguez 56d15dd3e5SLuis R. Rodriguez return skb; 57d15dd3e5SLuis R. Rodriguez } 58d15dd3e5SLuis R. Rodriguez EXPORT_SYMBOL(ath_rxbuf_alloc); 59