From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: Ankit Jindal <ankit.jindal@linaro.org> Cc: linux-kernel@vger.kernel.org, "Hans J. Koch" <hjk@hansjkoch.de>, patches@apm.com, linux-arm-kernel@lists.infradead.org, "Rob Herring" <robh+dt@kernel.org>, "Tushar Jagad" <tushar.jagad@linaro.org>, "Russell King - ARM Linux" <linux@arm.linux.org.uk>, devicetree@vger.kernel.org, "Guenter Roeck" <linux@roeck-us.net>, "Varka Bhadram" <varkabhadram@gmail.com>, "Kumar Gala" <galak@codeaurora.org>, "Anup Patel" <anup@brainfault.org>, "Andreas Färber" <afaerber@suse.de> Subject: Re: [PATCH v5 2/6] uio: Add new UIO_MEM_PHYS_CACHE type for mem regions Date: Wed, 26 Nov 2014 16:01:47 -0800 [thread overview] Message-ID: <20141127000147.GC5313@kroah.com> (raw) In-Reply-To: <1416220572-13381-3-git-send-email-ankit.jindal@linaro.org> On Mon, Nov 17, 2014 at 04:06:08PM +0530, Ankit Jindal wrote: > Currently, three types of mem regions are supported: UIO_MEM_PHYS, > UIO_MEM_LOGICAL and UIO_MEM_VIRTUAL. Among these UIO_MEM_PHYS helps > UIO driver export physcial memory to user space as non-cacheable > user memory. Typcially memory-mapped registers of a device are exported > to user space as UIO_MEM_PHYS type mem region. The UIO_MEM_PHYS type > is not efficient if dma-capable devices are capable of maintaining coherency > with CPU caches. Not efficient in what way? > This patch adds new type UIO_MEM_PHYS_CACHE for mem regions to enable > cacheable access to physical memory from user space. > > Signed-off-by: Ankit Jindal <ankit.jindal@linaro.org> > Signed-off-by: Tushar Jagad <tushar.jagad@linaro.org> > --- > drivers/uio/uio.c | 11 ++++++++--- > include/linux/uio_driver.h | 1 + > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c > index 97e6444..120a84b 100644 > --- a/drivers/uio/uio.c > +++ b/drivers/uio/uio.c > @@ -644,7 +644,7 @@ static const struct vm_operations_struct uio_physical_vm_ops = { > #endif > }; > > -static int uio_mmap_physical(struct vm_area_struct *vma) > +static int uio_mmap_physical(struct vm_area_struct *vma, bool cacheable) I despise "bool" flags in a function, as they don't give any idea of what is going on when you see the function being called. Please create a new function that does this properly, with a correct name, if it's needed. thanks, greg k-h
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From: gregkh@linuxfoundation.org (Greg Kroah-Hartman) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 2/6] uio: Add new UIO_MEM_PHYS_CACHE type for mem regions Date: Wed, 26 Nov 2014 16:01:47 -0800 [thread overview] Message-ID: <20141127000147.GC5313@kroah.com> (raw) In-Reply-To: <1416220572-13381-3-git-send-email-ankit.jindal@linaro.org> On Mon, Nov 17, 2014 at 04:06:08PM +0530, Ankit Jindal wrote: > Currently, three types of mem regions are supported: UIO_MEM_PHYS, > UIO_MEM_LOGICAL and UIO_MEM_VIRTUAL. Among these UIO_MEM_PHYS helps > UIO driver export physcial memory to user space as non-cacheable > user memory. Typcially memory-mapped registers of a device are exported > to user space as UIO_MEM_PHYS type mem region. The UIO_MEM_PHYS type > is not efficient if dma-capable devices are capable of maintaining coherency > with CPU caches. Not efficient in what way? > This patch adds new type UIO_MEM_PHYS_CACHE for mem regions to enable > cacheable access to physical memory from user space. > > Signed-off-by: Ankit Jindal <ankit.jindal@linaro.org> > Signed-off-by: Tushar Jagad <tushar.jagad@linaro.org> > --- > drivers/uio/uio.c | 11 ++++++++--- > include/linux/uio_driver.h | 1 + > 2 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c > index 97e6444..120a84b 100644 > --- a/drivers/uio/uio.c > +++ b/drivers/uio/uio.c > @@ -644,7 +644,7 @@ static const struct vm_operations_struct uio_physical_vm_ops = { > #endif > }; > > -static int uio_mmap_physical(struct vm_area_struct *vma) > +static int uio_mmap_physical(struct vm_area_struct *vma, bool cacheable) I despise "bool" flags in a function, as they don't give any idea of what is going on when you see the function being called. Please create a new function that does this properly, with a correct name, if it's needed. thanks, greg k-h
next prev parent reply other threads:[~2014-11-27 2:41 UTC|newest] Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-11-17 10:36 [PATCH v5 0/6] UIO driver for APM X-Gene QMTM Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-17 10:36 ` [PATCH v5 1/6] uio: code style cleanup Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-17 10:36 ` [PATCH v5 2/6] uio: Add new UIO_MEM_PHYS_CACHE type for mem regions Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-27 0:01 ` Greg Kroah-Hartman [this message] 2014-11-27 0:01 ` Greg Kroah-Hartman 2014-12-08 12:43 ` Ankit Jindal 2014-12-08 12:43 ` Ankit Jindal 2014-12-08 12:43 ` Ankit Jindal 2014-11-17 10:36 ` [PATCH v5 3/6] Documentation: Update documentation for UIO_MEM_PHYS_CACHE Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-17 10:36 ` [PATCH v5 4/6] uio: Add X-Gene QMTM UIO driver Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-17 10:36 ` [PATCH v5 5/6] Documentation: dt-bindings: Add binding info for " Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal 2014-11-17 10:43 ` Andreas Färber 2014-11-17 10:43 ` Andreas Färber 2014-11-17 10:43 ` Andreas Färber 2014-11-17 11:17 ` Arnd Bergmann 2014-11-17 11:17 ` Arnd Bergmann 2014-11-17 11:17 ` Arnd Bergmann 2014-11-18 9:29 ` Ankit Jindal 2014-11-18 9:29 ` Ankit Jindal 2014-11-18 9:29 ` Ankit Jindal 2014-11-18 13:10 ` Arnd Bergmann 2014-11-18 13:10 ` Arnd Bergmann 2014-11-18 13:10 ` Arnd Bergmann 2014-12-08 12:42 ` Ankit Jindal 2014-12-08 12:42 ` Ankit Jindal 2014-12-08 17:15 ` Rob Herring 2014-12-08 17:15 ` Rob Herring 2014-12-09 6:33 ` Ankit Jindal 2014-12-09 6:33 ` Ankit Jindal 2014-12-09 6:33 ` Ankit Jindal 2014-11-17 10:36 ` [PATCH v5 6/6] MAINTAINERS: Add entry for APM " Ankit Jindal 2014-11-17 10:36 ` Ankit Jindal
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