From mboxrd@z Thu Jan 1 00:00:00 1970 From: sricharan@codeaurora.org (Sricharan) Date: Fri, 6 Jan 2017 17:35:25 +0530 Subject: [PATCH V8 1/9] iommu: add IOMMU_PRIV attribute In-Reply-To: <20170106110627.GO17255@8bytes.org> References: <1483362764-11990-1-git-send-email-sricharan@codeaurora.org> <1483362764-11990-2-git-send-email-sricharan@codeaurora.org> <20170106110627.GO17255@8bytes.org> Message-ID: <00bc01d26815$2f357480$8da05d80$@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Joerg, >-----Original Message----- >From: linux-arm-kernel [mailto:linux-arm-kernel-bounces at lists.infradead.org] On Behalf Of Joerg Roedel >Sent: Friday, January 06, 2017 4:36 PM >To: Sricharan R >Cc: mitchelh at codeaurora.org; pdaly at codeaurora.org; vinod.koul at intel.com; jgebben at codeaurora.org; will.deacon at arm.com; >linux-kernel at vger.kernel.org; iommu at lists.linux-foundation.org; linux at armlinux.org.uk; jcrouse at codeaurora.org; >dan.j.williams at intel.com; pratikp at codeaurora.org; tzeng at codeaurora.org; linux-arm-kernel at lists.infradead.org; >robin.murphy at arm.com >Subject: Re: [PATCH V8 1/9] iommu: add IOMMU_PRIV attribute > >On Mon, Jan 02, 2017 at 06:42:36PM +0530, Sricharan R wrote: >> From: Mitchel Humpherys >> >> Add the IOMMU_PRIV attribute, which is used to indicate privileged >> mappings. >> >> Reviewed-by: Robin Murphy >> Tested-by: Robin Murphy >> Signed-off-by: Mitchel Humpherys >> Acked-by: Will Deacon >> --- >> include/linux/iommu.h | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/include/linux/iommu.h b/include/linux/iommu.h >> index 0ff5111..8c15ada 100644 >> --- a/include/linux/iommu.h >> +++ b/include/linux/iommu.h >> @@ -31,6 +31,7 @@ >> #define IOMMU_CACHE (1 << 2) /* DMA cache coherency */ >> #define IOMMU_NOEXEC (1 << 3) >> #define IOMMU_MMIO (1 << 4) /* e.g. things like MSI doorbells */ >> +#define IOMMU_PRIV (1 << 5) /* privileged */ > >Since this is a new generic global flag, can you please add a more >verbose comment telling what a 'privileged' mapping is about in the >iommu-case? We should have a clear defined semantic for this flag or we >might end up with different meanings for it with different >iommu-hardware. This flag is to inform the iommu api to setup privileged mappings for the caller which can be accessed only by the master running with supervisor/privileged permissions and inaccessible to less privileged execution levels. i will repost this with comment added. Regards, Sricharan