From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Sricharan" Subject: RE: [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error Date: Mon, 30 Jan 2017 13:31:52 +0530 Message-ID: <005001d27acf$21c47db0$654d7910$@codeaurora.org> References: <1485188293-20263-1-git-send-email-sricharan@codeaurora.org> <1485188293-20263-8-git-send-email-sricharan@codeaurora.org> <20170128210359.GE20550@bhelgaas-glaptop.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170128210359.GE20550@bhelgaas-glaptop.roam.corp.google.com> Content-Language: en-us Sender: linux-acpi-owner@vger.kernel.org To: 'Bjorn Helgaas' Cc: robin.murphy@arm.com, will.deacon@arm.com, joro@8bytes.org, lorenzo.pieralisi@arm.com, iommu@lists.linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, m.szyprowski@samsung.com, bhelgaas@google.com, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org Hi Bjorn, >-----Original Message----- >From: Bjorn Helgaas [mailto:helgaas@kernel.org] >Sent: Sunday, January 29, 2017 2:34 AM >To: Sricharan R >Cc: robin.murphy@arm.com; will.deacon@arm.com; joro@8bytes.org; lorenzo.pieralisi@arm.com; iommu@lists.linux-foundation.org; >linux-arm-kernel@lists.infradead.org; linux-arm-msm@vger.kernel.org; m.szyprowski@samsung.com; bhelgaas@google.com; linux- >pci@vger.kernel.org; linux-acpi@vger.kernel.org >Subject: Re: [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error > >On Mon, Jan 23, 2017 at 09:48:09PM +0530, Sricharan R wrote: >> From: Laurent Pinchart >> >> Failures to look up an IOMMU when parsing the DT iommus property need to >> be handled separately from the .of_xlate() failures to support deferred >> probing. >> >> The lack of a registered IOMMU can be caused by the lack of a driver for >> the IOMMU, the IOMMU device probe not having been performed yet, having >> been deferred, or having failed. >> >> The first case occurs when the device tree describes the bus master and >> IOMMU topology correctly but no device driver exists for the IOMMU yet >> or the device driver has not been compiled in. Return NULL, the caller >> will configure the device without an IOMMU. >> >> The second and third cases are handled by deferring the probe of the bus >> master device which will eventually get reprobed after the IOMMU. >> >> The last case is currently handled by deferring the probe of the bus >> master device as well. A mechanism to either configure the bus master >> device without an IOMMU or to fail the bus master device probe depending >> on whether the IOMMU is optional or mandatory would be a good >> enhancement. >> >> Signed-off-by: Laurent Pichart >> Signed-off-by: Sricharan R >> ... > >> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c >> index 349bd1d..9529d6c 100644 >> --- a/drivers/iommu/of_iommu.c >> +++ b/drivers/iommu/of_iommu.c >> @@ -23,6 +23,7 @@ >> #include >> #include >> #include >> +#include > >Why do we need this? Right, will remove it. Regards, Sricharan From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: "Sricharan" To: "'Bjorn Helgaas'" Cc: , , , , , , , , , , References: <1485188293-20263-1-git-send-email-sricharan@codeaurora.org> <1485188293-20263-8-git-send-email-sricharan@codeaurora.org> <20170128210359.GE20550@bhelgaas-glaptop.roam.corp.google.com> In-Reply-To: <20170128210359.GE20550@bhelgaas-glaptop.roam.corp.google.com> Subject: RE: [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error Date: Mon, 30 Jan 2017 13:31:52 +0530 Message-ID: <005001d27acf$21c47db0$654d7910$@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-ID: Hi Bjorn, >-----Original Message----- >From: Bjorn Helgaas [mailto:helgaas@kernel.org] >Sent: Sunday, January 29, 2017 2:34 AM >To: Sricharan R >Cc: robin.murphy@arm.com; will.deacon@arm.com; joro@8bytes.org; lorenzo.pieralisi@arm.com; iommu@lists.linux-foundation.org; >linux-arm-kernel@lists.infradead.org; linux-arm-msm@vger.kernel.org; m.szyprowski@samsung.com; bhelgaas@google.com; linux- >pci@vger.kernel.org; linux-acpi@vger.kernel.org >Subject: Re: [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error > >On Mon, Jan 23, 2017 at 09:48:09PM +0530, Sricharan R wrote: >> From: Laurent Pinchart >> >> Failures to look up an IOMMU when parsing the DT iommus property need to >> be handled separately from the .of_xlate() failures to support deferred >> probing. >> >> The lack of a registered IOMMU can be caused by the lack of a driver for >> the IOMMU, the IOMMU device probe not having been performed yet, having >> been deferred, or having failed. >> >> The first case occurs when the device tree describes the bus master and >> IOMMU topology correctly but no device driver exists for the IOMMU yet >> or the device driver has not been compiled in. Return NULL, the caller >> will configure the device without an IOMMU. >> >> The second and third cases are handled by deferring the probe of the bus >> master device which will eventually get reprobed after the IOMMU. >> >> The last case is currently handled by deferring the probe of the bus >> master device as well. A mechanism to either configure the bus master >> device without an IOMMU or to fail the bus master device probe depending >> on whether the IOMMU is optional or mandatory would be a good >> enhancement. >> >> Signed-off-by: Laurent Pichart >> Signed-off-by: Sricharan R >> ... > >> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c >> index 349bd1d..9529d6c 100644 >> --- a/drivers/iommu/of_iommu.c >> +++ b/drivers/iommu/of_iommu.c >> @@ -23,6 +23,7 @@ >> #include >> #include >> #include >> +#include > >Why do we need this? Right, will remove it. Regards, Sricharan From mboxrd@z Thu Jan 1 00:00:00 1970 From: sricharan@codeaurora.org (Sricharan) Date: Mon, 30 Jan 2017 13:31:52 +0530 Subject: [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error In-Reply-To: <20170128210359.GE20550@bhelgaas-glaptop.roam.corp.google.com> References: <1485188293-20263-1-git-send-email-sricharan@codeaurora.org> <1485188293-20263-8-git-send-email-sricharan@codeaurora.org> <20170128210359.GE20550@bhelgaas-glaptop.roam.corp.google.com> Message-ID: <005001d27acf$21c47db0$654d7910$@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Bjorn, >-----Original Message----- >From: Bjorn Helgaas [mailto:helgaas at kernel.org] >Sent: Sunday, January 29, 2017 2:34 AM >To: Sricharan R >Cc: robin.murphy at arm.com; will.deacon at arm.com; joro at 8bytes.org; lorenzo.pieralisi at arm.com; iommu at lists.linux-foundation.org; >linux-arm-kernel at lists.infradead.org; linux-arm-msm at vger.kernel.org; m.szyprowski at samsung.com; bhelgaas at google.com; linux- >pci at vger.kernel.org; linux-acpi at vger.kernel.org >Subject: Re: [PATCH V7 07/11] iommu: of: Handle IOMMU lookup failure with deferred probing or error > >On Mon, Jan 23, 2017 at 09:48:09PM +0530, Sricharan R wrote: >> From: Laurent Pinchart >> >> Failures to look up an IOMMU when parsing the DT iommus property need to >> be handled separately from the .of_xlate() failures to support deferred >> probing. >> >> The lack of a registered IOMMU can be caused by the lack of a driver for >> the IOMMU, the IOMMU device probe not having been performed yet, having >> been deferred, or having failed. >> >> The first case occurs when the device tree describes the bus master and >> IOMMU topology correctly but no device driver exists for the IOMMU yet >> or the device driver has not been compiled in. Return NULL, the caller >> will configure the device without an IOMMU. >> >> The second and third cases are handled by deferring the probe of the bus >> master device which will eventually get reprobed after the IOMMU. >> >> The last case is currently handled by deferring the probe of the bus >> master device as well. A mechanism to either configure the bus master >> device without an IOMMU or to fail the bus master device probe depending >> on whether the IOMMU is optional or mandatory would be a good >> enhancement. >> >> Signed-off-by: Laurent Pichart >> Signed-off-by: Sricharan R >> ... > >> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c >> index 349bd1d..9529d6c 100644 >> --- a/drivers/iommu/of_iommu.c >> +++ b/drivers/iommu/of_iommu.c >> @@ -23,6 +23,7 @@ >> #include >> #include >> #include >> +#include > >Why do we need this? Right, will remove it. Regards, Sricharan