From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751365AbaLQSCz (ORCPT ); Wed, 17 Dec 2014 13:02:55 -0500 Received: from devils.ext.ti.com ([198.47.26.153]:50174 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750790AbaLQSCx (ORCPT ); Wed, 17 Dec 2014 13:02:53 -0500 From: Murali Karicheri To: , , , , , , , CC: Murali Karicheri Subject: [RFC PATCH 1/2] common: dma-mapping: introduce dma_get_parent_cfg() helper Date: Wed, 17 Dec 2014 13:02:23 -0500 Message-ID: <1418839344-14393-2-git-send-email-m-karicheri2@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1418839344-14393-1-git-send-email-m-karicheri2@ti.com> References: <1418839344-14393-1-git-send-email-m-karicheri2@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Now, in Kernel, parent device's DMA parameters has to be applied to the child as is - to enable DMA support for the device. Usually this is happened in places where parent device manually instantiates child device such as in drivers/pci/probe.c (pci_device_add() for example). Now DMA configuration is represented in device data structure not only by DMA mask and DMA params, it also includes dma_pfn_offset at least. Hence introduce common dma_get_parent_cfg() helper to apply dma configuration from parent to child, and use __weak to allow arch to override it if needed. Signed-off-by: Murali Karicheri --- drivers/base/dma-mapping.c | 18 ++++++++++++++++++ include/linux/dma-mapping.h | 3 +++ 2 files changed, 21 insertions(+) diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 9e8bbdd..5322426 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -339,3 +339,21 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) vunmap(cpu_addr); } #endif + +int __weak dma_get_parent_cfg(struct device *dev, struct device *parent) +{ + struct device *temp = parent; + + if (!temp) + temp = dev->parent; + + if (temp && is_device_dma_capable(temp)) { + dev->dma_mask = temp->dma_mask; + dev->coherent_dma_mask = temp->coherent_dma_mask; + dev->dma_parms = temp->dma_parms; + dev->dma_pfn_offset = temp->dma_pfn_offset; + return 0; + } + return -EINVAL; +} +EXPORT_SYMBOL(dma_get_parent_cfg); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index d5d3881..eb080d6 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -127,6 +127,9 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask) return dma_set_mask_and_coherent(dev, mask); } +extern int __weak dma_get_parent_cfg(struct device *dev, + struct device *parent); + extern u64 dma_get_required_mask(struct device *dev); #ifndef set_arch_dma_coherent_ops -- 1.7.9.5