From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752596Ab3JaJRe (ORCPT ); Thu, 31 Oct 2013 05:17:34 -0400 Received: from co1ehsobe002.messaging.microsoft.com ([216.32.180.185]:34621 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751120Ab3JaJRc (ORCPT ); Thu, 31 Oct 2013 05:17:32 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: 3 X-BigFish: VS3(zzzz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6h1082kzz1de098h8275bh1de097hz2dh2a8h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh2222h1fb3h1d0ch1d2eh1d3fh1dc1h1dfeh1dffh1e23h1fe8h1ff5h2218h2216h1155h) From: Nicolin Chen To: , CC: Subject: [PATCH][RESEND] lib/genalloc: add a helper function for DMA buffer allocation Date: Thu, 31 Oct 2013 17:16:07 +0800 Message-ID: <1383210967-25804-1-git-send-email-b42378@freescale.com> X-Mailer: git-send-email 1.8.4 MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When using pool space for DMA buffer, there might be duplicated calling of gen_pool_alloc() and gen_pool_virt_to_phys() in each implementation. Thus it's better to add a simple helper function, a compatible one to the common dma_alloc_coherent(), to save some code. Signed-off-by: Nicolin Chen --- include/linux/genalloc.h | 2 ++ lib/genalloc.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h index f8d41cb..1eda33d 100644 --- a/include/linux/genalloc.h +++ b/include/linux/genalloc.h @@ -94,6 +94,8 @@ static inline int gen_pool_add(struct gen_pool *pool, unsigned long addr, } extern void gen_pool_destroy(struct gen_pool *); extern unsigned long gen_pool_alloc(struct gen_pool *, size_t); +extern void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, + dma_addr_t *dma); extern void gen_pool_free(struct gen_pool *, unsigned long, size_t); extern void gen_pool_for_each_chunk(struct gen_pool *, void (*)(struct gen_pool *, struct gen_pool_chunk *, void *), void *); diff --git a/lib/genalloc.c b/lib/genalloc.c index 26cf20b..dda3116 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -313,6 +313,34 @@ retry: EXPORT_SYMBOL(gen_pool_alloc); /** + * gen_pool_dma_alloc - allocate special memory from the pool for DMA usage + * @pool: pool to allocate from + * @size: number of bytes to allocate from the pool + * @dma: dma-view physical address + * + * Allocate the requested number of bytes from the specified pool. + * Uses the pool allocation function (with first-fit algorithm by default). + * Can not be used in NMI handler on architectures without + * NMI-safe cmpxchg implementation. + */ +void *gen_pool_dma_alloc(struct gen_pool *pool, size_t size, dma_addr_t *dma) +{ + unsigned long vaddr; + + if (!pool) + return NULL; + + vaddr = gen_pool_alloc(pool, size); + if (!vaddr) + return NULL; + + *dma = gen_pool_virt_to_phys(pool, vaddr); + + return (void *)vaddr; +} +EXPORT_SYMBOL(gen_pool_dma_alloc); + +/** * gen_pool_free - free allocated special memory back to the pool * @pool: pool to free to * @addr: starting address of memory to free back to pool -- 1.8.4