Hi Mark, On Sun, 3 Oct 2021 at 12:31, Mark Kettenis <kette...@openbsd.org> wrote: > > This uclass is intended to manage IOMMUs on systems where the > IOMMUs are not in bypass mode by default. In that case U-Boot > cannot ignore the IOMMUs if it wants to use devices that need > to do DMA and sit behind such an IOMMU. > > This initial IOMMU uclass implementation does not implement and > device ops and is intended for IOMMUs that have a bypass mode > that does not require address translation. Support for IOMMUs > that do require address translation is planned and device ops > will be defined when support for such IOMMUs will be added. > > Signed-off-by: Mark Kettenis <kette...@openbsd.org> > --- > drivers/Kconfig | 2 ++ > drivers/Makefile | 1 + > drivers/core/device.c | 8 +++++++ > drivers/iommu/Kconfig | 13 +++++++++++ > drivers/iommu/Makefile | 3 +++ > drivers/iommu/iommu-uclass.c | 45 ++++++++++++++++++++++++++++++++++++ > include/dm/uclass-id.h | 1 + > include/iommu.h | 16 +++++++++++++ > 8 files changed, 89 insertions(+) > create mode 100644 drivers/iommu/Kconfig > create mode 100644 drivers/iommu/Makefile > create mode 100644 drivers/iommu/iommu-uclass.c > create mode 100644 include/iommu.h > > diff --git a/drivers/Kconfig b/drivers/Kconfig > index 417d6f88c2..b26ca8cf70 100644 > --- a/drivers/Kconfig > +++ b/drivers/Kconfig > @@ -50,6 +50,8 @@ source "drivers/i2c/Kconfig" > > source "drivers/input/Kconfig" > > +source "drivers/iommu/Kconfig" > + > source "drivers/led/Kconfig" > > source "drivers/mailbox/Kconfig" > diff --git a/drivers/Makefile b/drivers/Makefile > index fd218c9056..166aeb9817 100644 > --- a/drivers/Makefile > +++ b/drivers/Makefile > @@ -109,6 +109,7 @@ obj-y += mtd/ > obj-y += pwm/ > obj-y += reset/ > obj-y += input/ > +obj-y += iommu/ > # SOC specific infrastructure drivers. > obj-y += smem/ > obj-y += thermal/ > diff --git a/drivers/core/device.c b/drivers/core/device.c > index 29668f6fb3..5f480ad443 100644 > --- a/drivers/core/device.c > +++ b/drivers/core/device.c > @@ -28,6 +28,7 @@ > #include <dm/uclass.h> > #include <dm/uclass-internal.h> > #include <dm/util.h> > +#include <iommu.h> > #include <linux/err.h> > #include <linux/list.h> > #include <power-domain.h> > @@ -543,6 +544,13 @@ int device_probe(struct udevice *dev) > goto fail; > } > > + if (CONFIG_IS_ENABLED(IOMMU) && dev->parent && > + (device_get_uclass_id(dev) != UCLASS_IOMMU)) { > + ret = dev_iommu_probe(dev); > + if (ret) > + goto fail; > + } > + > ret = device_get_dma_constraints(dev); > if (ret) > goto fail; > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > new file mode 100644 > index 0000000000..8cb377560e > --- /dev/null > +++ b/drivers/iommu/Kconfig > @@ -0,0 +1,13 @@ > +# > +# IOMMU devices > +# > + > +menu "IOMMU device drivers" > + > +config IOMMU > + bool "Enable Driver Model for IOMMU drivers" > + depends on DM > + help > + Enable driver model for IOMMU devices.
Need at least three lines. What is an IOMMU? How does it relate to other devices? > + > +endmenu > diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile > new file mode 100644 > index 0000000000..f1ceb10150 > --- /dev/null > +++ b/drivers/iommu/Makefile > @@ -0,0 +1,3 @@ > +# SPDX-License-Identifier: GPL-2.0+ > + > +obj-$(CONFIG_IOMMU) += iommu-uclass.o > diff --git a/drivers/iommu/iommu-uclass.c b/drivers/iommu/iommu-uclass.c > new file mode 100644 > index 0000000000..5c55df3066 > --- /dev/null > +++ b/drivers/iommu/iommu-uclass.c > @@ -0,0 +1,45 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Copyright (C) 2021 Mark Kettenis <kette...@openbsd.org> > + */ > + > +#define LOG_CATEGORY UCLASS_IOMMU > + > +#include <common.h> > +#include <dm.h> > + > +#if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) > +int dev_iommu_probe(struct udevice *dev) Can we rename to dev_iommus_enable()? I like to keep probe for use by DM itself so it is confusing to talk about probing in a context other than probing a single device. > +{ > + struct ofnode_phandle_args args; > + struct udevice *dev_iommu; > + int i, count, ret = 0; > + > + count = dev_count_phandle_with_args(dev, "iommus", > + "#iommu-cells", 0); Do you have a binding file you can add to docs/device-tree-bindings ? > + for (i = 0; i < count; i++) { > + ret = dev_read_phandle_with_args(dev, "iommus", > + "#iommu-cells", 0, i, &args); > + if (ret) { > + debug("%s: dev_read_phandle_with_args failed: %d\n", > + __func__, ret); > + return ret; > + } > + > + ret = uclass_get_device_by_ofnode(UCLASS_IOMMU, args.node, > + &dev_iommu); > + if (ret) { > + debug("%s: uclass_get_device_by_ofnode failed: %d\n", > + __func__, ret); > + return ret; > + } > + } > + > + return 0; > +} > +#endif > + > +UCLASS_DRIVER(iommu) = { > + .id = UCLASS_IOMMU, > + .name = "iommu", > +}; > diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h > index e7edd409f3..56aa981613 100644 > --- a/include/dm/uclass-id.h > +++ b/include/dm/uclass-id.h > @@ -61,6 +61,7 @@ enum uclass_id { > UCLASS_I2C_MUX, /* I2C multiplexer */ > UCLASS_I2S, /* I2S bus */ > UCLASS_IDE, /* IDE device */ > + UCLASS_IOMMU, /* IOMMU */ > UCLASS_IRQ, /* Interrupt controller */ > UCLASS_KEYBOARD, /* Keyboard input device */ > UCLASS_LED, /* Light-emitting diode (LED) */ > diff --git a/include/iommu.h b/include/iommu.h > new file mode 100644 > index 0000000000..d17a06a6f3 > --- /dev/null > +++ b/include/iommu.h > @@ -0,0 +1,16 @@ > +#ifndef _IOMMU_H > +#define _IOMMU_H > + > +struct udevice; > + > +#if (CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)) && \ > + CONFIG_IS_ENABLED(IOMMU) > +int dev_iommu_probe(struct udevice *dev); > +#else > +static inline int dev_iommu_probe(struct udevice *dev) > +{ > + return 0; > +} > +#endif > + > +#endif > -- > 2.33.0 > Regards, Simon