From: Will Deacon Subject: Re: [V4 PATCH 4/6] device property: Introduces device_dma_is_coherent() Date: Wed, 20 May 2015 11:28:29 +0100 Message-ID: <20150520102829.GB11498@arm.com> References: <1431724994-21601-1-git-send-email-Suravee.Suthikulpanit@amd.com> <1431724994-21601-5-git-send-email-Suravee.Suthikulpanit@amd.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "rjw@rjwysocki.net" , "lenb@kernel.org" , Catalin Marinas , "bhelgaas@google.com" , "thomas.lendacky@amd.com" , "herbert@gondor.apana.org.au" , "davem@davemloft.net" , "arnd@arndb.de" , "msalter@redhat.com" , "hanjun.guo@linaro.org" , "al.stone@linaro.org" , "grant.likely@linaro.org" , "leo.duran@amd.com" , "linux-arm-kernel@lists.infradead.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" , "netdev@vger.kernel.org" To: Suravee Suthikulpanit Return-path: Content-Disposition: inline In-Reply-To: <1431724994-21601-5-git-send-email-Suravee.Suthikulpanit@amd.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On Fri, May 15, 2015 at 10:23:12PM +0100, Suravee Suthikulpanit wrote: > Currently, device drivers, which support both OF and ACPI, > need to call two separate APIs, of_dma_is_coherent() and > acpi_dma_is_coherent()) to determine device coherency attribute. > > This patch simplifies this process by introducing a new device > property API, device_dma_is_coherent(), which calls the appropriate > interface based on the booting architecture. > > Signed-off-by: Suravee Suthikulpanit > CC: Rafael J. Wysocki > --- > drivers/base/property.c | 12 ++++++++++++ > include/linux/property.h | 2 ++ > 2 files changed, 14 insertions(+) > > diff --git a/drivers/base/property.c b/drivers/base/property.c > index 1d0b116..8123c6e 100644 > --- a/drivers/base/property.c > +++ b/drivers/base/property.c > @@ -14,6 +14,7 @@ > #include > #include > #include > +#include > #include > > /** > @@ -519,3 +520,14 @@ unsigned int device_get_child_node_count(struct device *dev) > return count; > } > EXPORT_SYMBOL_GPL(device_get_child_node_count); > + > +bool device_dma_is_coherent(struct device *dev) > +{ > + if (IS_ENABLED(CONFIG_OF) && dev->of_node) > + return of_dma_is_coherent(dev->of_node); > + else if (has_acpi_companion(dev)) > + return acpi_dma_is_coherent(acpi_node(dev->fwnode)); I don't think you need the has_acpi_companion check, as acpi_node handles this and acpi_dma_is_coherent(NULL) returns false. Will