From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Zhang Subject: Re: [v3 1/1] iommu/tegra: smmu: bus_notifier registers platform IOMMU devices Date: Wed, 05 Dec 2012 14:29:42 +0800 Message-ID: <50BEE9D6.2080107@gmail.com> References: <1354646264-12126-1-git-send-email-hdoyu@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1354646264-12126-1-git-send-email-hdoyu-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Hiroshi Doyu Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org List-Id: iommu@lists.linux-foundation.org On 12/05/2012 02:37 AM, Hiroshi Doyu wrote: > Most of platform devices are IOMMU'able in Tegra30 SoC. Registering > all IOMMU'able devices manually isn't nice. This patch allows > platform bus_notifier to register IOMMU devices. Map info can be > passed from DT. Info format is: > > dma-window = <0 0x40000000>; > > TODO: > A map can be shared with mutiple devices. This info also could be > passed from DT or default map can be set in advance. > > Signed-off-by: Hiroshi Doyu > --- > v3: Added bus_unregister_notifier > --- > drivers/iommu/tegra-smmu.c | 48 +++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 47 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c > index 25c1210..8fec9be 100644 > --- a/drivers/iommu/tegra-smmu.c > +++ b/drivers/iommu/tegra-smmu.c > @@ -38,6 +38,7 @@ > > #include > #include > +#include > > enum smmu_hwgrp { > HWGRP_AFI, > @@ -1273,13 +1274,58 @@ static struct platform_driver tegra_smmu_driver = { > }, > }; > > +static int tegra_smmu_device_notifier(struct notifier_block *nb, > + unsigned long event, void *_dev) > +{ > + struct dma_iommu_mapping *map = NULL; > + struct device *dev = _dev; > + dma_addr_t base; > + size_t size; > + int err; > + > + switch (event) { > + case BUS_NOTIFY_ADD_DEVICE: > + err = of_get_dma_window(dev->of_node, NULL, 0, NULL, &base, > + &size); > + if (!err) > + map = arm_iommu_create_mapping(&platform_bus_type, > + base, size, 0); > + if (IS_ERR_OR_NULL(map)) > + break; > + if (arm_iommu_attach_device(dev, map)) { > + arm_iommu_release_mapping(map); > + dev_err(dev, "Failed to attach %s\n", dev_name(dev)); > + } > + dev_dbg(dev, "Attached %s to map %p\n", dev_name(dev), map); If "arm_iommu_attach_device" fails, the "dev_err" and "dev_dbg" will all be called. > + break; > + default: > + break; > + } > + return NOTIFY_DONE; > +} > + > +static struct notifier_block tegra_smmu_device_nb = { > + .notifier_call = tegra_smmu_device_notifier, > +}; > + > static int __devinit tegra_smmu_init(void) > { > - return platform_driver_register(&tegra_smmu_driver); > + int err; > + > + err = platform_driver_register(&tegra_smmu_driver); > + if (err) > + return err; > + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) > + bus_register_notifier(&platform_bus_type, > + &tegra_smmu_device_nb); > + return 0; > } > > static void __exit tegra_smmu_exit(void) > { > + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) > + bus_unregister_notifier(&platform_bus_type, > + &tegra_smmu_device_nb); Okay. Here unregister the notifier, but where is the "arm_iommu_release_mapping" for every IOMMU'able devices? > platform_driver_unregister(&tegra_smmu_driver); > } > >