blob: fdfa39ec2a4d4a50d87d5fa9502efc7b1170bc61 [file] [log] [blame]
// 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 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 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,
.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 DEFINE_MUTEX(apple_dart_groups_lock);
static void apple_dart_release_group(void *iommu_data)
{
int i, sid;
struct apple_dart_stream_map *stream_map;
struct apple_dart_master_cfg *group_master_cfg = iommu_data;
mutex_lock(&apple_dart_groups_lock);
for_each_stream_map(i, group_master_cfg, stream_map)
for_each_set_bit(sid, &stream_map->sidmap, DART_MAX_STREAMS)
stream_map->dart->sid2group[sid] = NULL;
kfree(iommu_data);
mutex_unlock(&apple_dart_groups_lock);
}
static struct iommu_group *apple_dart_device_group(struct device *dev)
{
int i, sid;
struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
struct apple_dart_stream_map *stream_map;
struct apple_dart_master_cfg *group_master_cfg;
struct iommu_group *group = NULL;
struct iommu_group *res = ERR_PTR(-EINVAL);
mutex_lock(&apple_dart_groups_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);
res = ERR_PTR(-ENOMEM);
if (!group)
goto out;
group_master_cfg = kzalloc(sizeof(*group_master_cfg), GFP_KERNEL);
if (!group_master_cfg) {
iommu_group_put(group);
goto out;
}
memcpy(group_master_cfg, cfg, sizeof(*group_master_cfg));
iommu_group_set_iommudata(group, group_master_cfg,
apple_dart_release_group);
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(&apple_dart_groups_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@svenpeter.dev>");
MODULE_LICENSE("GPL v2");