From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sricharan R Subject: [PATCH V5 02/12] iommu/of: Prepare for deferred IOMMU configuration Date: Thu, 19 Jan 2017 20:35:46 +0530 Message-ID: <1484838356-24962-3-git-send-email-sricharan@codeaurora.org> References: <1484838356-24962-1-git-send-email-sricharan@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1484838356-24962-1-git-send-email-sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: robin.murphy-5wv7dgnIgG8@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org List-Id: linux-arm-msm@vger.kernel.org From: Robin Murphy IOMMU configuration represents unchanging properties of the hardware, and as such should only need happen once in a device's lifetime, but the necessary interaction with the IOMMU device and driver complicates exactly when that point should be. Since the only reasonable tool available for handling the inter-device dependency is probe deferral, we need to prepare of_iommu_configure() to run later than it is currently called (i.e. at driver probe rather than device creation), to handle being retried, and to tell whether a not-yet present IOMMU should be waited for or skipped (by virtue of having declared a built-in driver or not). Signed-off-by: Robin Murphy --- * No change drivers/iommu/of_iommu.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index ee49081..349bd1d 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -104,12 +104,20 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, int err; ops = iommu_get_instance(fwnode); - if (!ops || !ops->of_xlate) + if ((ops && !ops->of_xlate) || + (!ops && !of_match_node(&__iommu_of_table, iommu_spec->np))) return NULL; err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops); if (err) return ERR_PTR(err); + /* + * The otherwise-empty fwspec handily serves to indicate the specific + * IOMMU device we're waiting for, which will be useful if we ever get + * a proper probe-ordering dependency mechanism in future. + */ + if (!ops) + return ERR_PTR(-EPROBE_DEFER); err = ops->of_xlate(dev, iommu_spec); if (err) @@ -186,14 +194,34 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np) { const struct iommu_ops *ops; + struct iommu_fwspec *fwspec = dev->iommu_fwspec; if (!master_np) return NULL; + if (fwspec) { + if (fwspec->ops) + return fwspec->ops; + + /* In the deferred case, start again from scratch */ + iommu_fwspec_free(dev); + } + if (dev_is_pci(dev)) ops = of_pci_iommu_init(to_pci_dev(dev), master_np); else ops = of_platform_iommu_init(dev, master_np); + /* + * If we have reason to believe the IOMMU driver missed the initial + * add_device callback for dev, replay it to get things in order. + */ + if (!IS_ERR_OR_NULL(ops) && ops->add_device && + dev->bus && !dev->iommu_group) { + int err = ops->add_device(dev); + + if (err) + ops = ERR_PTR(err); + } return IS_ERR(ops) ? NULL : ops; } -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation From mboxrd@z Thu Jan 1 00:00:00 1970 From: sricharan@codeaurora.org (Sricharan R) Date: Thu, 19 Jan 2017 20:35:46 +0530 Subject: [PATCH V5 02/12] iommu/of: Prepare for deferred IOMMU configuration In-Reply-To: <1484838356-24962-1-git-send-email-sricharan@codeaurora.org> References: <1484838356-24962-1-git-send-email-sricharan@codeaurora.org> Message-ID: <1484838356-24962-3-git-send-email-sricharan@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Robin Murphy IOMMU configuration represents unchanging properties of the hardware, and as such should only need happen once in a device's lifetime, but the necessary interaction with the IOMMU device and driver complicates exactly when that point should be. Since the only reasonable tool available for handling the inter-device dependency is probe deferral, we need to prepare of_iommu_configure() to run later than it is currently called (i.e. at driver probe rather than device creation), to handle being retried, and to tell whether a not-yet present IOMMU should be waited for or skipped (by virtue of having declared a built-in driver or not). Signed-off-by: Robin Murphy --- * No change drivers/iommu/of_iommu.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index ee49081..349bd1d 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -104,12 +104,20 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index, int err; ops = iommu_get_instance(fwnode); - if (!ops || !ops->of_xlate) + if ((ops && !ops->of_xlate) || + (!ops && !of_match_node(&__iommu_of_table, iommu_spec->np))) return NULL; err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops); if (err) return ERR_PTR(err); + /* + * The otherwise-empty fwspec handily serves to indicate the specific + * IOMMU device we're waiting for, which will be useful if we ever get + * a proper probe-ordering dependency mechanism in future. + */ + if (!ops) + return ERR_PTR(-EPROBE_DEFER); err = ops->of_xlate(dev, iommu_spec); if (err) @@ -186,14 +194,34 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np) { const struct iommu_ops *ops; + struct iommu_fwspec *fwspec = dev->iommu_fwspec; if (!master_np) return NULL; + if (fwspec) { + if (fwspec->ops) + return fwspec->ops; + + /* In the deferred case, start again from scratch */ + iommu_fwspec_free(dev); + } + if (dev_is_pci(dev)) ops = of_pci_iommu_init(to_pci_dev(dev), master_np); else ops = of_platform_iommu_init(dev, master_np); + /* + * If we have reason to believe the IOMMU driver missed the initial + * add_device callback for dev, replay it to get things in order. + */ + if (!IS_ERR_OR_NULL(ops) && ops->add_device && + dev->bus && !dev->iommu_group) { + int err = ops->add_device(dev); + + if (err) + ops = ERR_PTR(err); + } return IS_ERR(ops) ? NULL : ops; } -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation