From: Simon Glass sjg@chromium.org Date: Mon, 20 Sep 2021 19:11:25 -0600
Hi Simon,
[..]
+static int apple_dart_bind(struct udevice *dev) +{
void *base;int sid, i;base = dev_read_addr_ptr(dev);if (!base)return -EINVAL;u32 params2 = readl(base + DART_PARAMS2);if (params2 & DART_PARAMS2_BYPASS_SUPPORT) {for (sid = 0; sid < 16; sid++) {writel(DART_TCR_BYPASS_DART | DART_TCR_BYPASS_DAPF,base + DART_TCR(sid));for (i = 0; i < 4; i++)writel(0, base + DART_TTBR(sid, i));}}Not allowed hardware access in bind(). Can this more to probe() ?
Well, I need to make sure that this happens before other drivers get probed (in particular the xhci-dwc3 driver). Is there a better mechanism to achieve that?
If those drivers have something in the DT indicating that they need this, then you can add a uclass_get_device_by_phandle() in those drivers.
Yes, there is an "iommus" property that points at the IOMMU. This is a standard property and I think it would make sense to have the core device probing code handle it in a way similar to how "power-domains" is handled. That way we don't have to add IOMMU hooks into each and every driver.
If not, then you can probe all the DART devices with uclass_probe_all().
Having said that, I see you are using UCLASS_MISC. I suspect this should have its own UCLASS_IOMMU.
So here is a proof-of-concept diff to add UCLASS_IOMMU. This deliberately does not yet introduce driver ops yet; coming up with something sensible there needs a bit more thought. For USB support all I need is for the probe function to put the IOMMU in bypass mode, so that is what's implemented here.
Does this look reasonable? I'll split this up eventually into a commit that adds UCLASS_IOMMU and a commit that adds the apple_dart driver.
commit 606979a32d8e0d19ee45df97ad6855c24e27e5ad Author: Mark Kettenis kettenis@openbsd.org Date: Sun Sep 26 22:35:30 2021 +0200
iommu: Proof of concept
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..d0638140af --- /dev/null +++ b/drivers/iommu/Kconfig @@ -0,0 +1,20 @@ +# +# 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. + +config APPLE_DART + bool "Apple DART support" + depends on IOMMU && ARCH_APPLE + default y + help + Enable support for the DART on Apple SoCs. + +endmenu diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile new file mode 100644 index 0000000000..8a50e3aba8 --- /dev/null +++ b/drivers/iommu/Makefile @@ -0,0 +1,5 @@ +# SPDX-License-Identifier: GPL-2.0+ + +obj-$(CONFIG_IOMMU) += iommu-uclass.o + +obj-$(CONFIG_APPLE_DART) += apple_dart.o diff --git a/drivers/iommu/apple_dart.c b/drivers/iommu/apple_dart.c new file mode 100644 index 0000000000..ff8c5fa62c --- /dev/null +++ b/drivers/iommu/apple_dart.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Mark Kettenis kettenis@openbsd.org + */ + +#include <common.h> +#include <cpu_func.h> +#include <dm.h> +#include <asm/io.h> + +#define DART_PARAMS2 0x0004 +#define DART_PARAMS2_BYPASS_SUPPORT BIT(0) +#define DART_TLB_OP 0x0020 +#define DART_TLB_OP_OPMASK (0xfff << 20) +#define DART_TLB_OP_FLUSH (0x001 << 20) +#define DART_TLB_OP_BUSY BIT(2) +#define DART_TLB_OP_SIDMASK 0x0034 +#define DART_ERROR_STATUS 0x0040 +#define DART_TCR(sid) (0x0100 + 4 * (sid)) +#define DART_TCR_TRANSLATE_ENABLE BIT(7) +#define DART_TCR_BYPASS_DART BIT(8) +#define DART_TCR_BYPASS_DAPF BIT(12) +#define DART_TTBR(sid, idx) (0x0200 + 16 * (sid) + 4 * (idx)) +#define DART_TTBR_VALID BIT(31) +#define DART_TTBR_SHIFT 12 + +static int apple_dart_probe(struct udevice *dev) +{ + void *base; + int sid, i; + + base = dev_read_addr_ptr(dev); + if (!base) + return -EINVAL; + + u32 params2 = readl(base + DART_PARAMS2); + if (params2 & DART_PARAMS2_BYPASS_SUPPORT) { + for (sid = 0; sid < 16; sid++) { + writel(DART_TCR_BYPASS_DART | DART_TCR_BYPASS_DAPF, + base + DART_TCR(sid)); + for (i = 0; i < 4; i++) + writel(0, base + DART_TTBR(sid, i)); + } + } + + return 0; +} + +static const struct udevice_id apple_dart_ids[] = { + { .compatible = "apple,t8103-dart" }, + { /* sentinel */ } +}; + +U_BOOT_DRIVER(apple_dart) = { + .name = "apple_dart", + .id = UCLASS_IOMMU, + .of_match = apple_dart_ids, + .probe = apple_dart_probe +}; 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 kettenis@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) +{ + 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); + 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) */