From 6ff6e184f1f4d4993d45ca3f934c8288890965fe Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 7 Dec 2023 14:03:09 -0400 Subject: [PATCH] iommmu/of: Do not return struct iommu_ops from of_iommu_configure() Nothing needs this pointer. Return a normal error code with the usual IOMMU semantic that ENODEV means 'there is no IOMMU driver'. Reviewed-by: Jerry Snitselaar Reviewed-by: Lu Baolu Acked-by: Rob Herring Tested-by: Hector Martin Signed-off-by: Jason Gunthorpe Link: https://lore.kernel.org/r/2-v2-16e4def25ebb+820-iommu_fwspec_p1_jgg@nvidia.com Signed-off-by: Joerg Roedel --- drivers/iommu/of_iommu.c | 31 +++++++++++++++++++------------ drivers/of/device.c | 22 +++++++++++++++------- include/linux/of_iommu.h | 13 ++++++------- 3 files changed, 40 insertions(+), 26 deletions(-) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 5ecca53847d3..c6510d7e7b24 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -107,16 +107,22 @@ static int of_iommu_configure_device(struct device_node *master_np, of_iommu_configure_dev(master_np, dev); } -const struct iommu_ops *of_iommu_configure(struct device *dev, - struct device_node *master_np, - const u32 *id) +/* + * Returns: + * 0 on success, an iommu was configured + * -ENODEV if the device does not have any IOMMU + * -EPROBEDEFER if probing should be tried again + * -errno fatal errors + */ +int of_iommu_configure(struct device *dev, struct device_node *master_np, + const u32 *id) { const struct iommu_ops *ops = NULL; struct iommu_fwspec *fwspec; int err = NO_IOMMU; if (!master_np) - return NULL; + return -ENODEV; /* Serialise to make dev->iommu stable under our potential fwspec */ mutex_lock(&iommu_probe_device_lock); @@ -124,7 +130,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, if (fwspec) { if (fwspec->ops) { mutex_unlock(&iommu_probe_device_lock); - return fwspec->ops; + return 0; } /* In the deferred case, start again from scratch */ iommu_fwspec_free(dev); @@ -169,14 +175,15 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, err = iommu_probe_device(dev); /* Ignore all other errors apart from EPROBE_DEFER */ - if (err == -EPROBE_DEFER) { - ops = ERR_PTR(err); - } else if (err < 0) { - dev_dbg(dev, "Adding to IOMMU failed: %d\n", err); - ops = NULL; + if (err < 0) { + if (err == -EPROBE_DEFER) + return err; + dev_dbg(dev, "Adding to IOMMU failed: %pe\n", ERR_PTR(err)); + return err; } - - return ops; + if (!ops) + return -ENODEV; + return 0; } static enum iommu_resv_type __maybe_unused diff --git a/drivers/of/device.c b/drivers/of/device.c index 65c71be71a8d..873d933e8e6d 100644 --- a/drivers/of/device.c +++ b/drivers/of/device.c @@ -93,12 +93,12 @@ of_dma_set_restricted_buffer(struct device *dev, struct device_node *np) int of_dma_configure_id(struct device *dev, struct device_node *np, bool force_dma, const u32 *id) { - const struct iommu_ops *iommu; const struct bus_dma_region *map = NULL; struct device_node *bus_np; u64 dma_start = 0; u64 mask, end, size = 0; bool coherent; + int iommu_ret; int ret; if (np == dev->of_node) @@ -181,21 +181,29 @@ int of_dma_configure_id(struct device *dev, struct device_node *np, dev_dbg(dev, "device is%sdma coherent\n", coherent ? " " : " not "); - iommu = of_iommu_configure(dev, np, id); - if (PTR_ERR(iommu) == -EPROBE_DEFER) { + iommu_ret = of_iommu_configure(dev, np, id); + if (iommu_ret == -EPROBE_DEFER) { /* Don't touch range map if it wasn't set from a valid dma-ranges */ if (!ret) dev->dma_range_map = NULL; kfree(map); return -EPROBE_DEFER; - } + } else if (iommu_ret == -ENODEV) { + dev_dbg(dev, "device is not behind an iommu\n"); + } else if (iommu_ret) { + dev_err(dev, "iommu configuration for device failed with %pe\n", + ERR_PTR(iommu_ret)); - dev_dbg(dev, "device is%sbehind an iommu\n", - iommu ? " " : " not "); + /* + * Historically this routine doesn't fail driver probing + * due to errors in of_iommu_configure() + */ + } else + dev_dbg(dev, "device is behind an iommu\n"); arch_setup_dma_ops(dev, dma_start, size, coherent); - if (!iommu) + if (iommu_ret) of_dma_set_restricted_buffer(dev, np); return 0; diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h index 9a5e6b410dd2..e61cbbe12dac 100644 --- a/include/linux/of_iommu.h +++ b/include/linux/of_iommu.h @@ -8,20 +8,19 @@ struct iommu_ops; #ifdef CONFIG_OF_IOMMU -extern const struct iommu_ops *of_iommu_configure(struct device *dev, - struct device_node *master_np, - const u32 *id); +extern int of_iommu_configure(struct device *dev, struct device_node *master_np, + const u32 *id); extern void of_iommu_get_resv_regions(struct device *dev, struct list_head *list); #else -static inline const struct iommu_ops *of_iommu_configure(struct device *dev, - struct device_node *master_np, - const u32 *id) +static inline int of_iommu_configure(struct device *dev, + struct device_node *master_np, + const u32 *id) { - return NULL; + return -ENODEV; } static inline void of_iommu_get_resv_regions(struct device *dev,