[PATCH v3 3/3] iommu: dart: Add DART iommu driver
From: Sven Peter
Date: Thu Jun 03 2021 - 04:50:39 EST
Apple's new SoCs use iommus for almost all peripherals. These Device
Address Resolution Tables must be setup before these peripherals can
act as DMA masters.
Signed-off-by: Sven Peter <sven@xxxxxxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/iommu/Kconfig | 15 +
drivers/iommu/Makefile | 1 +
drivers/iommu/apple-dart-iommu.c | 966 +++++++++++++++++++++++++++++++
4 files changed, 983 insertions(+)
create mode 100644 drivers/iommu/apple-dart-iommu.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 4373d63f9ccf..cb9200ad05fe 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1245,6 +1245,7 @@ M: Sven Peter <sven@xxxxxxxxxxxxx>
L: iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx
S: Maintained
F: Documentation/devicetree/bindings/iommu/apple,dart.yaml
+F: drivers/iommu/apple-dart-iommu.c
APPLE SMC DRIVER
M: Henrik Rydberg <rydberg@xxxxxxxxxxx>
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 1f111b399bca..87882c628b46 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -249,6 +249,21 @@ config SPAPR_TCE_IOMMU
Enables bits of IOMMU API required by VFIO. The iommu_ops
is not implemented as it is not necessary for VFIO.
+config IOMMU_APPLE_DART
+ tristate "Apple DART IOMMU Support"
+ depends on ARM64 || (COMPILE_TEST && !GENERIC_ATOMIC64)
+ select IOMMU_API
+ select IOMMU_IO_PGTABLE
+ select IOMMU_IO_PGTABLE_LPAE
+ default ARCH_APPLE
+ help
+ Support for Apple DART (Device Address Resolution Table) IOMMUs
+ found in Apple ARM SoCs like the M1.
+ This IOMMU is required for most peripherals using DMA to access
+ the main memory.
+
+ Say Y here if you are using an Apple SoC with a DART IOMMU.
+
# ARM IOMMU support
config ARM_SMMU
tristate "ARM Ltd. System MMU (SMMU) Support"
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index c0fb0ba88143..8c813f0ebc54 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -29,3 +29,4 @@ obj-$(CONFIG_HYPERV_IOMMU) += hyperv-iommu.o
obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
obj-$(CONFIG_IOMMU_SVA_LIB) += iommu-sva-lib.o io-pgfault.o
obj-$(CONFIG_SPRD_IOMMU) += sprd-iommu.o
+obj-$(CONFIG_IOMMU_APPLE_DART) += apple-dart-iommu.o
diff --git a/drivers/iommu/apple-dart-iommu.c b/drivers/iommu/apple-dart-iommu.c
new file mode 100644
index 000000000000..2777852498de
--- /dev/null
+++ b/drivers/iommu/apple-dart-iommu.c
@@ -0,0 +1,966 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Apple DART (Device Address Resolution Table) IOMMU driver
+ *
+ * Copyright (C) 2021 The Asahi Linux Contributors
+ *
+ * Based on arm/arm-smmu/arm-ssmu.c and arm/arm-smmu-v3/arm-smmu-v3.c
+ * Copyright (C) 2013 ARM Limited
+ * Copyright (C) 2015 ARM Limited
+ * and on exynos-iommu.c
+ * Copyright (c) 2011,2016 Samsung Electronics Co., Ltd.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/dma-iommu.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io-pgtable.h>
+#include <linux/iopoll.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_iommu.h>
+#include <linux/of_platform.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/ratelimit.h>
+#include <linux/slab.h>
+#include <linux/pci.h>
+
+#define DART_MAX_STREAMS 16
+#define DART_MAX_TTBR 4
+
+#define DART_STREAM_ALL 0xffff
+
+#define DART_PARAMS1 0x00
+#define DART_PARAMS_PAGE_SHIFT GENMASK(27, 24)
+
+#define DART_PARAMS2 0x04
+#define DART_PARAMS_BYPASS_SUPPORT BIT(0)
+
+#define DART_STREAM_COMMAND 0x20
+#define DART_STREAM_COMMAND_BUSY BIT(2)
+#define DART_STREAM_COMMAND_INVALIDATE BIT(20)
+
+#define DART_STREAM_SELECT 0x34
+
+#define DART_ERROR 0x40
+#define DART_ERROR_STREAM GENMASK(27, 24)
+#define DART_ERROR_CODE GENMASK(23, 0)
+#define DART_ERROR_FLAG BIT(31)
+#define DART_ERROR_READ_FAULT BIT(4)
+#define DART_ERROR_WRITE_FAULT BIT(3)
+#define DART_ERROR_NO_PTE BIT(2)
+#define DART_ERROR_NO_PMD BIT(1)
+#define DART_ERROR_NO_TTBR BIT(0)
+
+#define DART_CONFIG 0x60
+#define DART_CONFIG_LOCK BIT(15)
+
+#define DART_STREAM_COMMAND_BUSY_TIMEOUT 100
+
+#define DART_STREAM_REMAP 0x80
+
+#define DART_ERROR_ADDR_HI 0x54
+#define DART_ERROR_ADDR_LO 0x50
+
+#define DART_TCR(sid) (0x100 + 4 * (sid))
+#define DART_TCR_TRANSLATE_ENABLE BIT(7)
+#define DART_TCR_BYPASS0_ENABLE BIT(8)
+#define DART_TCR_BYPASS1_ENABLE BIT(12)
+
+#define DART_TTBR(sid, idx) (0x200 + 16 * (sid) + 4 * (idx))
+#define DART_TTBR_VALID BIT(31)
+#define DART_TTBR_SHIFT 12
+
+/*
+ * Private structure associated with each DART device.
+ *
+ * @dev: device struct
+ * @regs: mapped MMIO region
+ * @irq: interrupt number, can be shared with other DARTs
+ * @clks: clocks associated with this DART
+ * @num_clks: number of @clks
+ * @lock: lock for @used_sids and hardware operations involving this dart
+ * @used_sids: bitmap of streams attached to a domain
+ * @pgsize: pagesize supported by this DART
+ * @supports_bypass: indicates if this DART supports bypass mode
+ * @force_bypass: force bypass mode due to pagesize mismatch?
+ * @iommu: iommu core device
+ */
+struct apple_dart {
+ struct device *dev;
+
+ void __iomem *regs;
+
+ int irq;
+ struct clk_bulk_data *clks;
+ int num_clks;
+
+ spinlock_t lock;
+
+ u32 used_sids;
+ u32 pgsize;
+
+ u32 supports_bypass : 1;
+ u32 force_bypass : 1;
+ u64 force_bypass_offset;
+ u64 force_bypass_len;
+
+ struct iommu_device iommu;
+};
+
+/*
+ * This structure is used to identify a single stream attached to a domain.
+ * It's used as a list inside that domain to be able to attach multiple
+ * streams to a single domain. Since multiple devices can use a single stream
+ * it additionally keeps track of how many devices are represented by this
+ * stream. Once that number reaches zero it is detached from the IOMMU domain
+ * and all translations from this stream are disabled.
+ *
+ * @dart: DART instance to which this stream belongs
+ * @sid: stream id within the DART instance
+ * @num_devices: count of devices attached to this stream
+ * @stream_head: list head for the next stream
+ */
+struct apple_dart_stream {
+ struct apple_dart *dart;
+ u32 sid;
+
+ u32 num_devices;
+
+ struct list_head stream_head;
+};
+
+/*
+ * This structure is attached to each iommu domain handled by a DART.
+ * A single domain is used to represent a single virtual address spaces.
+ * It is always allocated together with a page table.
+ *
+ * Streams are the smallest units the DART hardware can differentiate.
+ * These are pointed to the page table of a domain whenever a device is
+ * attached to it. A single stream can only be assigned to a single domain.
+ *
+ * Devices are assigned to at least a single and sometimes multiple individual
+ * streams (using the iommus property in the device tree). Multiple devices
+ * can theoretically be represented by the same stream, though this is usually
+ * not the case.
+ *
+ * We only keep track of streams here and just count how many devices are
+ * represented by each stream. When the last device is removed the whole stream
+ * is removed from the domain.
+ *
+ * @dart: pointer to the DART instance
+ * @pgtbl_ops: pagetable ops allocated by io-pgtable
+ * @type: domain type IOMMU_DOMAIN_IDENTITY_{IDENTITY,DMA,UNMANAGED,BLOCKED}
+ * @streams: list of streams attached to this domain
+ * @lock: spinlock for operations involving the list of streams
+ * @domain: core iommu domain pointer
+ */
+struct apple_dart_domain {
+ struct apple_dart *dart;
+ struct io_pgtable_ops *pgtbl_ops;
+
+ unsigned int type;
+
+ struct list_head streams;
+
+ spinlock_t lock;
+
+ struct iommu_domain domain;
+};
+
+/*
+ * This structure is attached to devices with dev_iommu_priv_set() on of_xlate
+ * and contains a list of streams bound to this device as defined in the
+ * device tree. Multiple DART instances can be attached to a single device
+ * and each stream is identified by its stream id.
+ * It's usually reference by a pointer called *cfg.
+ *
+ * A dynamic array instead of a linked list is used here since in almost
+ * all cases a device will just be attached to a single stream and streams
+ * are never removed after they have been added.
+ *
+ * @num_streams: number of streams attached
+ * @streams: array of structs to identify attached streams and the device link
+ * to the iommu
+ */
+struct apple_dart_master_cfg {
+ int num_streams;
+ struct {
+ struct apple_dart *dart;
+ u32 sid;
+
+ struct device_link *link;
+ } streams[];
+};
+
+static struct platform_driver apple_dart_driver;
+static const struct iommu_ops apple_dart_iommu_ops;
+static const struct iommu_flush_ops apple_dart_tlb_ops;
+
+static struct apple_dart_domain *to_dart_domain(struct iommu_domain *dom)
+{
+ return container_of(dom, struct apple_dart_domain, domain);
+}
+
+static void apple_dart_hw_enable_translation(struct apple_dart *dart, u16 sid)
+{
+ writel(DART_TCR_TRANSLATE_ENABLE, dart->regs + DART_TCR(sid));
+}
+
+static void apple_dart_hw_disable_dma(struct apple_dart *dart, u16 sid)
+{
+ writel(0, dart->regs + DART_TCR(sid));
+}
+
+static void apple_dart_hw_enable_bypass(struct apple_dart *dart, u16 sid)
+{
+ WARN_ON(!dart->supports_bypass);
+ writel(DART_TCR_BYPASS0_ENABLE | DART_TCR_BYPASS1_ENABLE,
+ dart->regs + DART_TCR(sid));
+}
+
+static void apple_dart_hw_set_ttbr(struct apple_dart *dart, u16 sid, u16 idx,
+ phys_addr_t paddr)
+{
+ writel(DART_TTBR_VALID | (paddr >> DART_TTBR_SHIFT),
+ dart->regs + DART_TTBR(sid, idx));
+}
+
+static void apple_dart_hw_clear_ttbr(struct apple_dart *dart, u16 sid, u16 idx)
+{
+ writel(0, dart->regs + DART_TTBR(sid, idx));
+}
+
+static void apple_dart_hw_clear_all_ttbrs(struct apple_dart *dart, u16 sid)
+{
+ int i;
+
+ for (i = 0; i < 4; ++i)
+ apple_dart_hw_clear_ttbr(dart, sid, i);
+}
+
+static int apple_dart_hw_stream_command(struct apple_dart *dart, u16 sid_bitmap,
+ u32 command)
+{
+ unsigned long flags;
+ int ret;
+ u32 command_reg;
+
+ spin_lock_irqsave(&dart->lock, flags);
+
+ writel(sid_bitmap, dart->regs + DART_STREAM_SELECT);
+ writel(command, dart->regs + DART_STREAM_COMMAND);
+
+ ret = readl_poll_timeout_atomic(
+ dart->regs + DART_STREAM_COMMAND, command_reg,
+ !(command_reg & DART_STREAM_COMMAND_BUSY), 1,
+ DART_STREAM_COMMAND_BUSY_TIMEOUT);
+
+ spin_unlock_irqrestore(&dart->lock, flags);
+
+ if (ret) {
+ dev_err(dart->dev,
+ "busy bit did not clear after command %x for streams %x\n",
+ command, sid_bitmap);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int apple_dart_hw_invalidate_tlb_global(struct apple_dart *dart)
+{
+ return apple_dart_hw_stream_command(dart, DART_STREAM_ALL,
+ DART_STREAM_COMMAND_INVALIDATE);
+}
+
+static int apple_dart_hw_invalidate_tlb_stream(struct apple_dart *dart, u16 sid)
+{
+ return apple_dart_hw_stream_command(dart, 1 << sid,
+ DART_STREAM_COMMAND_INVALIDATE);
+}
+
+static int apple_dart_hw_reset(struct apple_dart *dart)
+{
+ int sid;
+ u32 config;
+
+ config = readl(dart->regs + DART_CONFIG);
+ if (config & DART_CONFIG_LOCK) {
+ dev_err(dart->dev, "DART is locked down until reboot: %08x\n",
+ config);
+ return -EINVAL;
+ }
+
+ for (sid = 0; sid < DART_MAX_STREAMS; ++sid) {
+ apple_dart_hw_disable_dma(dart, sid);
+ apple_dart_hw_clear_all_ttbrs(dart, sid);
+ apple_dart_hw_enable_translation(dart, sid);
+ }
+
+ /* restore stream identity map */
+ writel(0x03020100, dart->regs + DART_STREAM_REMAP);
+ writel(0x07060504, dart->regs + DART_STREAM_REMAP + 4);
+ writel(0x0b0a0908, dart->regs + DART_STREAM_REMAP + 8);
+ writel(0x0f0e0d0c, dart->regs + DART_STREAM_REMAP + 12);
+
+ /* clear any pending errors before the interrupt is unmasked */
+ writel(readl(dart->regs + DART_ERROR), dart->regs + DART_ERROR);
+
+ return apple_dart_hw_invalidate_tlb_global(dart);
+}
+
+static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain)
+{
+ unsigned long flags;
+ struct apple_dart_stream *stream;
+ struct apple_dart *dart = domain->dart;
+
+ if (!dart)
+ return;
+
+ spin_lock_irqsave(&domain->lock, flags);
+ list_for_each_entry(stream, &domain->streams, stream_head) {
+ apple_dart_hw_invalidate_tlb_stream(stream->dart, stream->sid);
+ }
+ spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+static void apple_dart_flush_iotlb_all(struct iommu_domain *domain)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ apple_dart_domain_flush_tlb(dart_domain);
+}
+
+static void apple_dart_iotlb_sync(struct iommu_domain *domain,
+ struct iommu_iotlb_gather *gather)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ apple_dart_domain_flush_tlb(dart_domain);
+}
+
+static void apple_dart_iotlb_sync_map(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ apple_dart_domain_flush_tlb(dart_domain);
+}
+
+static void apple_dart_tlb_flush_all(void *cookie)
+{
+ struct apple_dart_domain *domain = cookie;
+
+ apple_dart_domain_flush_tlb(domain);
+}
+
+static void apple_dart_tlb_flush_walk(unsigned long iova, size_t size,
+ size_t granule, void *cookie)
+{
+ struct apple_dart_domain *domain = cookie;
+
+ apple_dart_domain_flush_tlb(domain);
+}
+
+static const struct iommu_flush_ops apple_dart_tlb_ops = {
+ .tlb_flush_all = apple_dart_tlb_flush_all,
+ .tlb_flush_walk = apple_dart_tlb_flush_walk,
+ .tlb_add_page = NULL,
+};
+
+static phys_addr_t apple_dart_iova_to_phys(struct iommu_domain *domain,
+ dma_addr_t iova)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
+
+ if (domain->type == IOMMU_DOMAIN_IDENTITY)
+ return iova;
+ if (!ops)
+ return -ENODEV;
+
+ return ops->iova_to_phys(ops, iova);
+}
+
+static int apple_dart_map(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t size, int prot, gfp_t gfp)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
+
+ if (!ops)
+ return -ENODEV;
+ if (prot & IOMMU_MMIO)
+ return -EINVAL;
+ if (prot & IOMMU_NOEXEC)
+ return -EINVAL;
+
+ return ops->map(ops, iova, paddr, size, prot, gfp);
+}
+
+static size_t apple_dart_unmap(struct iommu_domain *domain, unsigned long iova,
+ size_t size, struct iommu_iotlb_gather *gather)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
+
+ if (!ops)
+ return 0;
+
+ return ops->unmap(ops, iova, size, gather);
+}
+
+static int apple_dart_domain_needs_pgtbl_ops(struct apple_dart *dart,
+ struct iommu_domain *domain)
+{
+ if (domain->type == IOMMU_DOMAIN_DMA)
+ return 1;
+ if (domain->type == IOMMU_DOMAIN_UNMANAGED)
+ return 1;
+ if (!dart->supports_bypass && domain->type == IOMMU_DOMAIN_IDENTITY)
+ return 1;
+ return 0;
+}
+
+/* must be called with held dart_domain->lock */
+static int apple_dart_finalize_domain(struct iommu_domain *domain)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct apple_dart *dart = dart_domain->dart;
+ struct io_pgtable_cfg pgtbl_cfg;
+
+ if (dart_domain->pgtbl_ops)
+ return 0;
+ if (!apple_dart_domain_needs_pgtbl_ops(dart, domain))
+ return 0;
+
+ pgtbl_cfg = (struct io_pgtable_cfg){
+ .pgsize_bitmap = dart->pgsize,
+ .ias = 32,
+ .oas = 36,
+ .coherent_walk = 1,
+ .tlb = &apple_dart_tlb_ops,
+ .iommu_dev = dart->dev,
+ };
+
+ dart_domain->pgtbl_ops =
+ alloc_io_pgtable_ops(ARM_APPLE_DART, &pgtbl_cfg, domain);
+ if (!dart_domain->pgtbl_ops)
+ return -ENOMEM;
+
+ domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap;
+ domain->geometry.aperture_start = 0;
+ domain->geometry.aperture_end = DMA_BIT_MASK(32);
+ domain->geometry.force_aperture = true;
+
+ // HACK: create a static pagetable to fake bypass mode
+ if (domain->type == IOMMU_DOMAIN_IDENTITY) {
+ u64 addr;
+
+ for (addr = 0; addr < dart->force_bypass_len;
+ addr += dart->pgsize)
+ dart_domain->pgtbl_ops->map(
+ dart_domain->pgtbl_ops, addr,
+ dart->force_bypass_offset + addr, dart->pgsize,
+ IOMMU_READ | IOMMU_WRITE, GFP_ATOMIC);
+ }
+
+ return 0;
+}
+
+static void apple_dart_stream_setup_ttbrs(struct apple_dart_domain *domain,
+ struct apple_dart *dart, u32 sid)
+{
+ int i;
+ struct io_pgtable_cfg *pgtbl_cfg =
+ &io_pgtable_ops_to_pgtable(domain->pgtbl_ops)->cfg;
+
+ for (i = 0; i < pgtbl_cfg->apple_dart_cfg.n_ttbrs; ++i)
+ apple_dart_hw_set_ttbr(dart, sid, i,
+ pgtbl_cfg->apple_dart_cfg.ttbr[i]);
+ for (; i < DART_MAX_TTBR; ++i)
+ apple_dart_hw_clear_ttbr(dart, sid, i);
+}
+
+/* must be called with held domain->lock */
+static int apple_dart_attach_stream(struct apple_dart_domain *domain,
+ struct apple_dart *dart, u32 sid)
+{
+ unsigned long flags;
+ struct apple_dart_stream *stream;
+ int ret;
+
+ if (WARN_ON(dart->force_bypass &&
+ domain->type != IOMMU_DOMAIN_IDENTITY))
+ return -EINVAL;
+
+ /*
+ * we can't mix and match DARTs that support bypass mode with those who don't
+ * because the iova space in fake bypass mode generally has an offset
+ */
+ if (WARN_ON(domain->type == IOMMU_DOMAIN_IDENTITY &&
+ (domain->dart->supports_bypass != dart->supports_bypass)))
+ return -EINVAL;
+
+ list_for_each_entry(stream, &domain->streams, stream_head) {
+ if (stream->dart == dart && stream->sid == sid) {
+ stream->num_devices++;
+ return 0;
+ }
+ }
+
+ spin_lock_irqsave(&dart->lock, flags);
+
+ if (WARN_ON(dart->used_sids & BIT(sid))) {
+ ret = -EINVAL;
+ goto error;
+ }
+
+ stream = kzalloc(sizeof(*stream), GFP_ATOMIC);
+ if (!stream) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ stream->dart = dart;
+ stream->sid = sid;
+ stream->num_devices = 1;
+ list_add(&stream->stream_head, &domain->streams);
+
+ dart->used_sids |= BIT(sid);
+ spin_unlock_irqrestore(&dart->lock, flags);
+
+ apple_dart_hw_clear_all_ttbrs(stream->dart, stream->sid);
+
+ switch (domain->type) {
+ case IOMMU_DOMAIN_IDENTITY:
+ if (stream->dart->supports_bypass) {
+ apple_dart_hw_enable_bypass(stream->dart, stream->sid);
+ } else {
+ apple_dart_stream_setup_ttbrs(domain, stream->dart,
+ stream->sid);
+ apple_dart_hw_enable_translation(stream->dart,
+ stream->sid);
+ apple_dart_hw_invalidate_tlb_stream(stream->dart,
+ stream->sid);
+ }
+ break;
+ case IOMMU_DOMAIN_BLOCKED:
+ apple_dart_hw_disable_dma(stream->dart, stream->sid);
+ break;
+ case IOMMU_DOMAIN_UNMANAGED:
+ case IOMMU_DOMAIN_DMA:
+ apple_dart_stream_setup_ttbrs(domain, stream->dart,
+ stream->sid);
+ apple_dart_hw_enable_translation(stream->dart, stream->sid);
+ apple_dart_hw_invalidate_tlb_stream(stream->dart, stream->sid);
+ break;
+ }
+
+ return 0;
+
+error:
+ spin_unlock_irqrestore(&dart->lock, flags);
+ return ret;
+}
+
+static void apple_dart_disable_stream(struct apple_dart *dart, u32 sid)
+{
+ unsigned long flags;
+
+ apple_dart_hw_disable_dma(dart, sid);
+ apple_dart_hw_clear_all_ttbrs(dart, sid);
+ apple_dart_hw_invalidate_tlb_stream(dart, sid);
+
+ spin_lock_irqsave(&dart->lock, flags);
+ dart->used_sids &= ~BIT(sid);
+ spin_unlock_irqrestore(&dart->lock, flags);
+}
+
+/* must be called with held domain->lock */
+static void apple_dart_detach_stream(struct apple_dart_domain *domain,
+ struct apple_dart *dart, u32 sid)
+{
+ struct apple_dart_stream *stream;
+
+ list_for_each_entry(stream, &domain->streams, stream_head) {
+ if (stream->dart == dart && stream->sid == sid) {
+ stream->num_devices--;
+
+ if (stream->num_devices == 0) {
+ apple_dart_disable_stream(dart, sid);
+ list_del(&stream->stream_head);
+ kfree(stream);
+ }
+ return;
+ }
+ }
+}
+
+static int apple_dart_attach_dev(struct iommu_domain *domain,
+ struct device *dev)
+{
+ int ret;
+ int i, j;
+ unsigned long flags;
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct apple_dart *dart = cfg->streams[0].dart;
+
+ spin_lock_irqsave(&dart_domain->lock, flags);
+
+ if (!dart_domain->dart)
+ dart_domain->dart = dart;
+
+ if (WARN_ON(dart->force_bypass &&
+ dart_domain->type != IOMMU_DOMAIN_IDENTITY)) {
+ dev_warn(
+ dev,
+ "IOMMU must be in bypass mode but trying to attach to translated domain.\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = apple_dart_finalize_domain(domain);
+ if (ret)
+ goto out;
+
+ for (i = 0; i < cfg->num_streams; ++i) {
+ ret = apple_dart_attach_stream(
+ dart_domain, cfg->streams[i].dart, cfg->streams[i].sid);
+ if (ret) {
+ /* try to undo what we did before returning */
+ for (j = 0; j < i; ++j)
+ apple_dart_detach_stream(dart_domain,
+ cfg->streams[j].dart,
+ cfg->streams[j].sid);
+
+ goto out;
+ }
+ }
+
+ ret = 0;
+
+out:
+ spin_unlock_irqrestore(&dart_domain->lock, flags);
+ return ret;
+}
+
+static void apple_dart_detach_dev(struct iommu_domain *domain,
+ struct device *dev)
+{
+ int i;
+ unsigned long flags;
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ spin_lock_irqsave(&dart_domain->lock, flags);
+
+ for (i = 0; i < cfg->num_streams; ++i)
+ apple_dart_detach_stream(dart_domain, cfg->streams[i].dart,
+ cfg->streams[i].sid);
+
+ spin_unlock_irqrestore(&dart_domain->lock, flags);
+}
+
+static struct iommu_device *apple_dart_probe_device(struct device *dev)
+{
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ int i;
+
+ if (!cfg)
+ return ERR_PTR(-ENODEV);
+
+ for (i = 0; i < cfg->num_streams; ++i) {
+ cfg->streams[i].link =
+ device_link_add(dev, cfg->streams[i].dart->dev,
+ DL_FLAG_PM_RUNTIME | DL_FLAG_STATELESS);
+ }
+
+ return &cfg->streams[0].dart->iommu;
+}
+
+static void apple_dart_release_device(struct device *dev)
+{
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ int i;
+
+ if (!cfg)
+ return;
+
+ for (i = 0; i < cfg->num_streams; ++i)
+ device_link_del(cfg->streams[i].link);
+
+ dev_iommu_priv_set(dev, NULL);
+ kfree(cfg);
+}
+
+static struct iommu_domain *apple_dart_domain_alloc(unsigned int type)
+{
+ struct apple_dart_domain *dart_domain;
+
+ if (type != IOMMU_DOMAIN_DMA && type != IOMMU_DOMAIN_UNMANAGED &&
+ type != IOMMU_DOMAIN_IDENTITY && type != IOMMU_DOMAIN_BLOCKED)
+ return NULL;
+
+ dart_domain = kzalloc(sizeof(*dart_domain), GFP_KERNEL);
+ if (!dart_domain)
+ return NULL;
+
+ INIT_LIST_HEAD(&dart_domain->streams);
+ spin_lock_init(&dart_domain->lock);
+ iommu_get_dma_cookie(&dart_domain->domain);
+ dart_domain->type = type;
+
+ return &dart_domain->domain;
+}
+
+static void apple_dart_domain_free(struct iommu_domain *domain)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ WARN_ON(!list_empty(&dart_domain->streams));
+
+ kfree(dart_domain);
+}
+
+static int apple_dart_of_xlate(struct device *dev, struct of_phandle_args *args)
+{
+ struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ unsigned int num_streams = cfg ? cfg->num_streams : 0;
+ struct apple_dart_master_cfg *cfg_new;
+ struct apple_dart *dart = platform_get_drvdata(iommu_pdev);
+
+ if (args->args_count != 1)
+ return -EINVAL;
+
+ cfg_new = krealloc(cfg, struct_size(cfg, streams, num_streams + 1),
+ GFP_KERNEL);
+ if (!cfg_new)
+ return -ENOMEM;
+
+ cfg = cfg_new;
+ dev_iommu_priv_set(dev, cfg);
+
+ cfg->num_streams = num_streams;
+ cfg->streams[cfg->num_streams].dart = dart;
+ cfg->streams[cfg->num_streams].sid = args->args[0];
+ cfg->num_streams++;
+
+ return 0;
+}
+
+static struct iommu_group *apple_dart_device_group(struct device *dev)
+{
+#ifdef CONFIG_PCI
+ struct iommu_group *group;
+
+ if (dev_is_pci(dev))
+ group = pci_device_group(dev);
+ else
+ group = generic_device_group(dev);
+
+ return group;
+#else
+ return generic_device_group(dev);
+#endif
+}
+
+static const struct iommu_ops apple_dart_iommu_ops = {
+ .domain_alloc = apple_dart_domain_alloc,
+ .domain_free = apple_dart_domain_free,
+ .attach_dev = apple_dart_attach_dev,
+ .detach_dev = apple_dart_detach_dev,
+ .map = apple_dart_map,
+ .unmap = apple_dart_unmap,
+ .flush_iotlb_all = apple_dart_flush_iotlb_all,
+ .iotlb_sync = apple_dart_iotlb_sync,
+ .iotlb_sync_map = apple_dart_iotlb_sync_map,
+ .iova_to_phys = apple_dart_iova_to_phys,
+ .probe_device = apple_dart_probe_device,
+ .release_device = apple_dart_release_device,
+ .device_group = apple_dart_device_group,
+ .of_xlate = apple_dart_of_xlate,
+ .pgsize_bitmap = -1UL, /* Restricted during dart probe */
+};
+
+static irqreturn_t apple_dart_irq(int irq, void *dev)
+{
+ struct apple_dart *dart = dev;
+ static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
+ DEFAULT_RATELIMIT_BURST);
+ const char *fault_name = NULL;
+ u32 error = readl(dart->regs + DART_ERROR);
+ u32 error_code = FIELD_GET(DART_ERROR_CODE, error);
+ u32 addr_lo = readl(dart->regs + DART_ERROR_ADDR_LO);
+ u32 addr_hi = readl(dart->regs + DART_ERROR_ADDR_HI);
+ u64 addr = addr_lo | (((u64)addr_hi) << 32);
+ u8 stream_idx = FIELD_GET(DART_ERROR_STREAM, error);
+
+ if (!(error & DART_ERROR_FLAG))
+ return IRQ_NONE;
+
+ if (error_code & DART_ERROR_READ_FAULT)
+ fault_name = "READ FAULT";
+ else if (error_code & DART_ERROR_WRITE_FAULT)
+ fault_name = "WRITE FAULT";
+ else if (error_code & DART_ERROR_NO_PTE)
+ fault_name = "NO PTE FOR IOVA";
+ else if (error_code & DART_ERROR_NO_PMD)
+ fault_name = "NO PMD FOR IOVA";
+ else if (error_code & DART_ERROR_NO_TTBR)
+ fault_name = "NO TTBR FOR IOVA";
+
+ if (WARN_ON(fault_name == NULL))
+ fault_name = "unknown";
+
+ if (__ratelimit(&rs)) {
+ dev_err(dart->dev,
+ "translation fault: status:0x%x stream:%d code:0x%x (%s) at 0x%llx",
+ error, stream_idx, error_code, fault_name, addr);
+ }
+
+ writel(error, dart->regs + DART_ERROR);
+ return IRQ_HANDLED;
+}
+
+static int apple_dart_probe(struct platform_device *pdev)
+{
+ int ret;
+ u32 dart_params[2];
+ struct resource *res;
+ struct apple_dart *dart;
+ struct device *dev = &pdev->dev;
+
+ dart = devm_kzalloc(dev, sizeof(*dart), GFP_KERNEL);
+ if (!dart)
+ return -ENOMEM;
+
+ dart->dev = dev;
+ spin_lock_init(&dart->lock);
+
+ if (pdev->num_resources < 1)
+ return -ENODEV;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (resource_size(res) < 0x4000) {
+ dev_err(dev, "MMIO region too small (%pr)\n", res);
+ return -EINVAL;
+ }
+
+ dart->regs = devm_ioremap_resource(dev, res);
+ if (IS_ERR(dart->regs))
+ return PTR_ERR(dart->regs);
+
+ ret = devm_clk_bulk_get_all(dev, &dart->clks);
+ if (ret < 0)
+ return ret;
+ dart->num_clks = ret;
+
+ ret = clk_bulk_prepare_enable(dart->num_clks, dart->clks);
+ if (ret)
+ return ret;
+
+ ret = apple_dart_hw_reset(dart);
+ if (ret)
+ return ret;
+
+ dart_params[0] = readl(dart->regs + DART_PARAMS1);
+ dart_params[1] = readl(dart->regs + DART_PARAMS2);
+ dart->pgsize = 1 << FIELD_GET(DART_PARAMS_PAGE_SHIFT, dart_params[0]);
+ dart->supports_bypass = dart_params[1] & DART_PARAMS_BYPASS_SUPPORT;
+ dart->force_bypass = dart->pgsize > PAGE_SIZE;
+
+ // HACK: these shouldn't be hardcoded here but come from the device tree
+ dart->force_bypass_offset = 0x0800000000;
+ dart->force_bypass_len = 0x0100000000;
+
+ dart->irq = platform_get_irq(pdev, 0);
+ if (dart->irq < 0)
+ return -ENODEV;
+
+ ret = devm_request_irq(dart->dev, dart->irq, apple_dart_irq,
+ IRQF_SHARED, "apple-dart fault handler", dart);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, dart);
+
+ ret = iommu_device_sysfs_add(&dart->iommu, dev, NULL, "apple-dart.%s",
+ dev_name(&pdev->dev));
+ if (ret)
+ return ret;
+
+ ret = iommu_device_register(&dart->iommu, &apple_dart_iommu_ops, dev);
+ if (ret)
+ return ret;
+
+ if (dev->bus->iommu_ops != &apple_dart_iommu_ops) {
+ ret = bus_set_iommu(dev->bus, &apple_dart_iommu_ops);
+ if (ret)
+ return ret;
+ }
+#ifdef CONFIG_PCI
+ if (dev->bus->iommu_ops != pci_bus_type.iommu_ops) {
+ ret = bus_set_iommu(&pci_bus_type, &apple_dart_iommu_ops);
+ if (ret)
+ return ret;
+ }
+#endif
+
+ dev_info(
+ &pdev->dev,
+ "DART [pagesize %x, bypass support: %d, bypass forced: %d] initialized\n",
+ dart->pgsize, dart->supports_bypass, dart->force_bypass);
+ return 0;
+}
+
+static int apple_dart_remove(struct platform_device *pdev)
+{
+ struct apple_dart *dart = platform_get_drvdata(pdev);
+
+ devm_free_irq(dart->dev, dart->irq, dart);
+
+ iommu_device_unregister(&dart->iommu);
+ iommu_device_sysfs_remove(&dart->iommu);
+
+ clk_bulk_disable(dart->num_clks, dart->clks);
+ clk_bulk_unprepare(dart->num_clks, dart->clks);
+
+ return 0;
+}
+
+static void apple_dart_shutdown(struct platform_device *pdev)
+{
+ apple_dart_remove(pdev);
+}
+
+static const struct of_device_id apple_dart_of_match[] = {
+ { .compatible = "apple,t8103-dart", .data = NULL },
+ {},
+};
+MODULE_DEVICE_TABLE(of, apple_dart_of_match);
+
+static struct platform_driver apple_dart_driver = {
+ .driver = {
+ .name = "apple-dart",
+ .of_match_table = apple_dart_of_match,
+ },
+ .probe = apple_dart_probe,
+ .remove = apple_dart_remove,
+ .shutdown = apple_dart_shutdown,
+};
+module_platform_driver(apple_dart_driver);
+
+MODULE_DESCRIPTION("IOMMU API for Apple's DART");
+MODULE_AUTHOR("Sven Peter <sven@xxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
--
2.25.1