[PATCH v5 3/3] iommu/dart: Add DART iommu driver
Sven Peter
sven at svenpeter.dev
Tue Aug 3 05:16:51 PDT 2021
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.
Tested-by: Alyssa Rosenzweig <alyssa at rosenzweig.io>
Signed-off-by: Sven Peter <sven at svenpeter.dev>
---
MAINTAINERS | 1 +
drivers/iommu/Kconfig | 14 +
drivers/iommu/Makefile | 1 +
drivers/iommu/apple-dart.c | 923 +++++++++++++++++++++++++++++++++++++
4 files changed, 939 insertions(+)
create mode 100644 drivers/iommu/apple-dart.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 0f450f7d5336..5f3ef4298594 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1267,6 +1267,7 @@ M: Sven Peter <sven at svenpeter.dev>
L: iommu at lists.linux-foundation.org
S: Maintained
F: Documentation/devicetree/bindings/iommu/apple,dart.yaml
+F: drivers/iommu/apple-dart.c
APPLE SMC DRIVER
M: Henrik Rydberg <rydberg at bitmath.org>
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index c84da8205be7..dfe81da483e9 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -290,6 +290,20 @@ 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 APPLE_DART
+ tristate "Apple DART IOMMU Support"
+ depends on ARM64 || (COMPILE_TEST && !GENERIC_ATOMIC64)
+ select IOMMU_API
+ 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.
+
# 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..bc7f730edbb0 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_APPLE_DART) += apple-dart.o
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
new file mode 100644
index 000000000000..559db9259e65
--- /dev/null
+++ b/drivers/iommu/apple-dart.c
@@ -0,0 +1,923 @@
+// 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/atomic.h>
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/dev_printk.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/iommu.h>
+#include <linux/iopoll.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/slab.h>
+#include <linux/swab.h>
+#include <linux/types.h>
+
+#define DART_MAX_STREAMS 16
+#define DART_MAX_TTBR 4
+#define MAX_DARTS_PER_DEVICE 2
+
+#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(11, 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_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 hardware operations involving this dart
+ * @pgsize: pagesize supported by this DART
+ * @supports_bypass: indicates if this DART supports bypass mode
+ * @force_bypass: force bypass mode due to pagesize mismatch?
+ * @sid2group: maps stream ids to iommu_groups
+ * @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 pgsize;
+ u32 supports_bypass : 1;
+ u32 force_bypass : 1;
+
+ struct iommu_group *sid2group[DART_MAX_STREAMS];
+ struct iommu_device iommu;
+};
+
+/*
+ * Convenience struct to identify streams.
+ *
+ * The normal variant is used inside apple_dart_master_cfg which isn't written
+ * to concurrently.
+ * The atomic variant is used inside apple_dart_domain where we have to guard
+ * against races from potential parallel calls to attach/detach_device.
+ * Note that even inside the atomic variant the apple_dart pointer is not
+ * protected: This pointer is initialized once under the domain init mutex
+ * and never changed again afterwards. Devices with different dart pointers
+ * cannot be attached to the same domain.
+ *
+ * @dart dart pointer
+ * @sid stream id bitmap
+ */
+struct apple_dart_stream_map {
+ struct apple_dart *dart;
+ unsigned long sidmap;
+};
+struct apple_dart_atomic_stream_map {
+ struct apple_dart *dart;
+ atomic64_t sidmap;
+};
+
+/*
+ * This structure is attached to each iommu domain handled by a DART.
+ *
+ * @pgtbl_ops: pagetable ops allocated by io-pgtable
+ * @finalized: true if the domain has been completely initialized
+ * @init_lock: protects domain initialization
+ * @stream_maps: streams attached to this domain (valid for DMA/UNMANAGED only)
+ * @domain: core iommu domain pointer
+ */
+struct apple_dart_domain {
+ struct io_pgtable_ops *pgtbl_ops;
+
+ bool finalized;
+ struct mutex init_lock;
+ struct apple_dart_atomic_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
+
+ 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.
+ * So far the worst case seen is a single device with two streams
+ * from different darts, such that this simple static array is enough.
+ *
+ * @streams: streams for this device
+ */
+struct apple_dart_master_cfg {
+ struct apple_dart_stream_map stream_maps[MAX_DARTS_PER_DEVICE];
+};
+
+/*
+ * Helper macro to iterate over apple_dart_master_cfg.stream_maps and
+ * apple_dart_domain.stream_maps
+ *
+ * @i int used as loop variable
+ * @base pointer to base struct (apple_dart_master_cfg or apple_dart_domain)
+ * @stream pointer to the apple_dart_streams struct for each loop iteration
+ */
+#define for_each_stream_map(i, base, stream_map) \
+ for (i = 0, stream_map = &(base)->stream_maps[0]; \
+ i < MAX_DARTS_PER_DEVICE && stream_map->dart; \
+ stream_map = &(base)->stream_maps[++i])
+
+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_stream_map *stream_map)
+{
+ int sid;
+
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
+ writel(DART_TCR_TRANSLATE_ENABLE,
+ stream_map->dart->regs + DART_TCR(sid));
+}
+
+static void apple_dart_hw_disable_dma(struct apple_dart_stream_map *stream_map)
+{
+ int sid;
+
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
+ writel(0, stream_map->dart->regs + DART_TCR(sid));
+}
+
+static void
+apple_dart_hw_enable_bypass(struct apple_dart_stream_map *stream_map)
+{
+ int sid;
+
+ WARN_ON(!stream_map->dart->supports_bypass);
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
+ writel(DART_TCR_BYPASS0_ENABLE | DART_TCR_BYPASS1_ENABLE,
+ stream_map->dart->regs + DART_TCR(sid));
+}
+
+static void apple_dart_hw_set_ttbr(struct apple_dart_stream_map *stream_map,
+ u8 idx, phys_addr_t paddr)
+{
+ int sid;
+
+ WARN_ON(paddr & ((1 << DART_TTBR_SHIFT) - 1));
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
+ writel(DART_TTBR_VALID | (paddr >> DART_TTBR_SHIFT),
+ stream_map->dart->regs + DART_TTBR(sid, idx));
+}
+
+static void apple_dart_hw_clear_ttbr(struct apple_dart_stream_map *stream_map,
+ u8 idx)
+{
+ int sid;
+
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
+ writel(0, stream_map->dart->regs + DART_TTBR(sid, idx));
+}
+
+static void
+apple_dart_hw_clear_all_ttbrs(struct apple_dart_stream_map *stream_map)
+{
+ int i;
+
+ for (i = 0; i < DART_MAX_TTBR; ++i)
+ apple_dart_hw_clear_ttbr(stream_map, i);
+}
+
+static int
+apple_dart_hw_stream_command(struct apple_dart_stream_map *stream_map,
+ u32 command)
+{
+ unsigned long flags;
+ int ret;
+ u32 command_reg;
+
+ spin_lock_irqsave(&stream_map->dart->lock, flags);
+
+ writel(stream_map->sidmap, stream_map->dart->regs + DART_STREAM_SELECT);
+ writel(command, stream_map->dart->regs + DART_STREAM_COMMAND);
+
+ ret = readl_poll_timeout_atomic(
+ stream_map->dart->regs + DART_STREAM_COMMAND, command_reg,
+ !(command_reg & DART_STREAM_COMMAND_BUSY), 1,
+ DART_STREAM_COMMAND_BUSY_TIMEOUT);
+
+ spin_unlock_irqrestore(&stream_map->dart->lock, flags);
+
+ if (ret) {
+ dev_err(stream_map->dart->dev,
+ "busy bit did not clear after command %x for streams %lx\n",
+ command, stream_map->sidmap);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int
+apple_dart_hw_invalidate_tlb(struct apple_dart_stream_map *stream_map)
+{
+ return apple_dart_hw_stream_command(stream_map,
+ DART_STREAM_COMMAND_INVALIDATE);
+}
+
+static int apple_dart_hw_reset(struct apple_dart *dart)
+{
+ u32 config;
+ struct apple_dart_stream_map stream_map;
+
+ 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;
+ }
+
+ stream_map.dart = dart;
+ stream_map.sidmap = DART_STREAM_ALL;
+ apple_dart_hw_disable_dma(&stream_map);
+ apple_dart_hw_clear_all_ttbrs(&stream_map);
+
+ /* 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(&stream_map);
+}
+
+static void apple_dart_domain_flush_tlb(struct apple_dart_domain *domain)
+{
+ int i;
+ struct apple_dart_atomic_stream_map *domain_stream_map;
+ struct apple_dart_stream_map stream_map;
+
+ for_each_stream_map(i, domain, domain_stream_map) {
+ stream_map.dart = domain_stream_map->dart;
+ stream_map.sidmap = atomic64_read(&domain_stream_map->sidmap);
+ apple_dart_hw_invalidate_tlb(&stream_map);
+ }
+}
+
+static void apple_dart_flush_iotlb_all(struct iommu_domain *domain)
+{
+ apple_dart_domain_flush_tlb(to_dart_domain(domain));
+}
+
+static void apple_dart_iotlb_sync(struct iommu_domain *domain,
+ struct iommu_iotlb_gather *gather)
+{
+ apple_dart_domain_flush_tlb(to_dart_domain(domain));
+}
+
+static void apple_dart_iotlb_sync_map(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ apple_dart_domain_flush_tlb(to_dart_domain(domain));
+}
+
+static void apple_dart_tlb_flush_all(void *cookie)
+{
+ apple_dart_domain_flush_tlb(cookie);
+}
+
+static void apple_dart_tlb_flush_walk(unsigned long iova, size_t size,
+ size_t granule, void *cookie)
+{
+ apple_dart_domain_flush_tlb(cookie);
+}
+
+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,
+};
+
+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 (!ops)
+ return 0;
+
+ return ops->iova_to_phys(ops, iova);
+}
+
+static int apple_dart_map_pages(struct iommu_domain *domain, unsigned long iova,
+ phys_addr_t paddr, size_t pgsize,
+ size_t pgcount, int prot, gfp_t gfp,
+ size_t *mapped)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
+
+ if (!ops)
+ return -ENODEV;
+
+ return ops->map_pages(ops, iova, paddr, pgsize, pgcount, prot, gfp,
+ mapped);
+}
+
+static size_t apple_dart_unmap_pages(struct iommu_domain *domain,
+ unsigned long iova, size_t pgsize,
+ size_t pgcount,
+ struct iommu_iotlb_gather *gather)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct io_pgtable_ops *ops = dart_domain->pgtbl_ops;
+
+ return ops->unmap_pages(ops, iova, pgsize, pgcount, gather);
+}
+
+static void
+apple_dart_setup_translation(struct apple_dart_domain *domain,
+ struct apple_dart_stream_map *stream_map)
+{
+ 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(stream_map, i,
+ pgtbl_cfg->apple_dart_cfg.ttbr[i]);
+ for (; i < DART_MAX_TTBR; ++i)
+ apple_dart_hw_clear_ttbr(stream_map, i);
+
+ apple_dart_hw_enable_translation(stream_map);
+ apple_dart_hw_invalidate_tlb(stream_map);
+}
+
+static int apple_dart_finalize_domain(struct iommu_domain *domain,
+ struct apple_dart_master_cfg *cfg)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+ struct apple_dart *dart = cfg->stream_maps[0].dart;
+ struct io_pgtable_cfg pgtbl_cfg;
+ int ret = 0;
+ int i;
+
+ mutex_lock(&dart_domain->init_lock);
+
+ if (dart_domain->finalized)
+ goto done;
+
+ for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
+ dart_domain->stream_maps[i].dart = cfg->stream_maps[i].dart;
+ atomic64_set(&dart_domain->stream_maps[i].sidmap,
+ cfg->stream_maps[i].sidmap);
+ }
+
+ 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(APPLE_DART, &pgtbl_cfg, domain);
+ if (!dart_domain->pgtbl_ops) {
+ ret = -ENOMEM;
+ goto done;
+ }
+
+ 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;
+
+ dart_domain->finalized = true;
+
+done:
+ mutex_unlock(&dart_domain->init_lock);
+ return ret;
+}
+
+static int
+apple_dart_mod_streams(struct apple_dart_atomic_stream_map *domain_maps,
+ struct apple_dart_stream_map *master_maps,
+ bool add_streams)
+{
+ int i;
+
+ for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
+ if (domain_maps[i].dart != master_maps[i].dart)
+ return -EINVAL;
+ }
+
+ for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
+ if (!domain_maps[i].dart)
+ break;
+ if (add_streams)
+ atomic64_or(master_maps[i].sidmap,
+ &domain_maps[i].sidmap);
+ else
+ atomic64_and(~master_maps[i].sidmap,
+ &domain_maps[i].sidmap);
+ }
+
+ return 0;
+}
+
+static int apple_dart_domain_add_streams(struct apple_dart_domain *domain,
+ struct apple_dart_master_cfg *cfg)
+{
+ return apple_dart_mod_streams(domain->stream_maps, cfg->stream_maps,
+ true);
+}
+
+static int apple_dart_domain_remove_streams(struct apple_dart_domain *domain,
+ struct apple_dart_master_cfg *cfg)
+{
+ return apple_dart_mod_streams(domain->stream_maps, cfg->stream_maps,
+ false);
+}
+
+static int apple_dart_attach_dev(struct iommu_domain *domain,
+ struct device *dev)
+{
+ int ret, i;
+ struct apple_dart_stream_map *stream_map;
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ if (cfg->stream_maps[0].dart->force_bypass &&
+ domain->type != IOMMU_DOMAIN_IDENTITY)
+ return -EINVAL;
+ if (!cfg->stream_maps[0].dart->supports_bypass &&
+ domain->type == IOMMU_DOMAIN_IDENTITY)
+ return -EINVAL;
+
+ ret = apple_dart_finalize_domain(domain, cfg);
+ if (ret)
+ return ret;
+
+ switch (domain->type) {
+ case IOMMU_DOMAIN_DMA:
+ case IOMMU_DOMAIN_UNMANAGED:
+ ret = apple_dart_domain_add_streams(dart_domain, cfg);
+ if (ret)
+ return ret;
+
+ for_each_stream_map(i, cfg, stream_map)
+ apple_dart_setup_translation(dart_domain, stream_map);
+ break;
+ case IOMMU_DOMAIN_BLOCKED:
+ for_each_stream_map(i, cfg, stream_map)
+ apple_dart_hw_disable_dma(stream_map);
+ break;
+ case IOMMU_DOMAIN_IDENTITY:
+ for_each_stream_map(i, cfg, stream_map)
+ apple_dart_hw_enable_bypass(stream_map);
+ break;
+ }
+
+ return ret;
+}
+
+static void apple_dart_detach_dev(struct iommu_domain *domain,
+ struct device *dev)
+{
+ int i;
+ struct apple_dart_stream_map *stream_map;
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ for_each_stream_map(i, cfg, stream_map)
+ apple_dart_hw_disable_dma(stream_map);
+
+ if (domain->type == IOMMU_DOMAIN_DMA ||
+ domain->type == IOMMU_DOMAIN_UNMANAGED)
+ apple_dart_domain_remove_streams(dart_domain, cfg);
+}
+
+static struct iommu_device *apple_dart_probe_device(struct device *dev)
+{
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct apple_dart_stream_map *stream_map;
+ int i;
+
+ if (!cfg)
+ return ERR_PTR(-ENODEV);
+
+ for_each_stream_map(i, cfg, stream_map)
+ device_link_add(
+ dev, stream_map->dart->dev,
+ DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER);
+
+ return &cfg->stream_maps[0].dart->iommu;
+}
+
+static void apple_dart_release_device(struct device *dev)
+{
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+
+ if (!cfg)
+ return;
+
+ 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;
+
+ iommu_get_dma_cookie(&dart_domain->domain);
+ mutex_init(&dart_domain->init_lock);
+
+ /* no need to allocate pgtbl_ops or do any other finalization steps */
+ if (type == IOMMU_DOMAIN_IDENTITY || type == IOMMU_DOMAIN_BLOCKED)
+ dart_domain->finalized = true;
+
+ return &dart_domain->domain;
+}
+
+static void apple_dart_domain_free(struct iommu_domain *domain)
+{
+ struct apple_dart_domain *dart_domain = to_dart_domain(domain);
+
+ if (dart_domain->pgtbl_ops)
+ free_io_pgtable_ops(dart_domain->pgtbl_ops);
+
+ kfree(dart_domain);
+}
+
+static int apple_dart_of_xlate(struct device *dev, struct of_phandle_args *args)
+{
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct platform_device *iommu_pdev = of_find_device_by_node(args->np);
+ struct apple_dart *dart = platform_get_drvdata(iommu_pdev);
+ struct apple_dart *cfg_dart;
+ int i, sid;
+
+ if (args->args_count != 1)
+ return -EINVAL;
+ sid = args->args[0];
+
+ if (!cfg)
+ cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+ if (!cfg)
+ return -ENOMEM;
+ dev_iommu_priv_set(dev, cfg);
+
+ cfg_dart = cfg->stream_maps[0].dart;
+ if (cfg_dart) {
+ if (cfg_dart->supports_bypass != dart->supports_bypass)
+ return -EINVAL;
+ if (cfg_dart->force_bypass != dart->force_bypass)
+ return -EINVAL;
+ if (cfg_dart->pgsize != dart->pgsize)
+ return -EINVAL;
+ }
+
+ for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
+ if (cfg->stream_maps[i].dart == dart) {
+ cfg->stream_maps[i].sidmap |= 1 << sid;
+ return 0;
+ }
+ }
+ for (i = 0; i < MAX_DARTS_PER_DEVICE; ++i) {
+ if (!cfg->stream_maps[i].dart) {
+ cfg->stream_maps[i].dart = dart;
+ cfg->stream_maps[i].sidmap = 1 << sid;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static struct iommu_group *apple_dart_device_group(struct device *dev)
+{
+ static DEFINE_MUTEX(lock);
+ int i, sid;
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+ struct apple_dart_stream_map *stream_map;
+ struct iommu_group *group = NULL;
+ struct iommu_group *res = ERR_PTR(-EINVAL);
+
+ mutex_lock(&lock);
+
+ for_each_stream_map(i, cfg, stream_map) {
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS) {
+ struct iommu_group *stream_group =
+ stream_map->dart->sid2group[sid];
+
+ if (group && group != stream_group) {
+ res = ERR_PTR(-EINVAL);
+ goto out;
+ }
+
+ group = stream_group;
+ }
+ }
+
+ if (group) {
+ res = iommu_group_ref_get(group);
+ goto out;
+ }
+
+#ifdef CONFIG_PCI
+ if (dev_is_pci(dev))
+ group = pci_device_group(dev);
+ else
+#endif
+ group = generic_device_group(dev);
+
+ for_each_stream_map(i, cfg, stream_map)
+ for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
+ stream_map->dart->sid2group[sid] = group;
+
+ res = group;
+
+out:
+ mutex_unlock(&lock);
+ return res;
+}
+
+static int apple_dart_def_domain_type(struct device *dev)
+{
+ struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
+
+ if (cfg->stream_maps[0].dart->force_bypass)
+ return IOMMU_DOMAIN_IDENTITY;
+ if (!cfg->stream_maps[0].dart->supports_bypass)
+ return IOMMU_DOMAIN_DMA;
+
+ return 0;
+}
+
+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_pages = apple_dart_map_pages,
+ .unmap_pages = apple_dart_unmap_pages,
+ .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,
+ .def_domain_type = apple_dart_def_domain_type,
+ .pgsize_bitmap = -1UL, /* Restricted during dart probe */
+};
+
+static irqreturn_t apple_dart_irq(int irq, void *dev)
+{
+ struct apple_dart *dart = dev;
+ 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;
+
+ /* there should only be a single bit set but let's use == to be sure */
+ 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";
+ else
+ fault_name = "unknown";
+
+ dev_err_ratelimited(
+ 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_set_bus_ops(const struct iommu_ops *ops)
+{
+ int ret;
+
+ if (!iommu_present(&platform_bus_type)) {
+ ret = bus_set_iommu(&platform_bus_type, ops);
+ if (ret)
+ return ret;
+ }
+#ifdef CONFIG_PCI
+ if (!iommu_present(&pci_bus_type)) {
+ ret = bus_set_iommu(&pci_bus_type, ops);
+ if (ret) {
+ bus_set_iommu(&platform_bus_type, NULL);
+ return ret;
+ }
+ }
+#endif
+ return 0;
+}
+
+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);
+
+ 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);
+
+ dart->irq = platform_get_irq(pdev, 0);
+ if (dart->irq < 0)
+ return -ENODEV;
+
+ 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)
+ goto err_clk_disable;
+
+ 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;
+
+ ret = request_irq(dart->irq, apple_dart_irq, IRQF_SHARED,
+ "apple-dart fault handler", dart);
+ if (ret)
+ goto err_clk_disable;
+
+ platform_set_drvdata(pdev, dart);
+
+ ret = apple_dart_set_bus_ops(&apple_dart_iommu_ops);
+ if (ret)
+ goto err_free_irq;
+
+ ret = iommu_device_sysfs_add(&dart->iommu, dev, NULL, "apple-dart.%s",
+ dev_name(&pdev->dev));
+ if (ret)
+ goto err_remove_bus_ops;
+
+ ret = iommu_device_register(&dart->iommu, &apple_dart_iommu_ops, dev);
+ if (ret)
+ goto err_sysfs_remove;
+
+ 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;
+
+err_sysfs_remove:
+ iommu_device_sysfs_remove(&dart->iommu);
+err_remove_bus_ops:
+ apple_dart_set_bus_ops(NULL);
+err_free_irq:
+ free_irq(dart->irq, dart);
+err_clk_disable:
+ clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
+
+ return ret;
+}
+
+static int apple_dart_remove(struct platform_device *pdev)
+{
+ struct apple_dart *dart = platform_get_drvdata(pdev);
+
+ apple_dart_hw_reset(dart);
+ free_irq(dart->irq, dart);
+ apple_dart_set_bus_ops(NULL);
+
+ iommu_device_unregister(&dart->iommu);
+ iommu_device_sysfs_remove(&dart->iommu);
+
+ clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
+
+ return 0;
+}
+
+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,
+ .suppress_bind_attrs = true,
+ },
+ .probe = apple_dart_probe,
+ .remove = apple_dart_remove,
+};
+
+module_platform_driver(apple_dart_driver);
+
+MODULE_DESCRIPTION("IOMMU API for Apple's DART");
+MODULE_AUTHOR("Sven Peter <sven at svenpeter.dev>");
+MODULE_LICENSE("GPL v2");
--
2.25.1
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