Re: [PATCH 7/7] iommu: dart: Add t8110 DART support

From: Sven Peter
Date: Wed Jan 04 2023 - 08:50:40 EST


On Wed, Jan 4, 2023, at 12:00, Hector Martin wrote:
> Now that we have the driver properly parameterized, we can add support
> for T8110 DARTs. These DARTs drop the multiple TTBRs (which only make
> sense with legacy 4K page platforms) and instead add support for new
> features and more stream IDs. The register layout is different, but the
> pagetable format is the same as T6000.
>
> Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
> ---

One minor nit below, otherwise

Reviewed-by: Sven Peter <sven@xxxxxxxxxxxxx>


> drivers/iommu/apple-dart.c | 206 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 201 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
> index 396da83f2f9e..e9cbdb45448c 100644
> --- a/drivers/iommu/apple-dart.c
> +++ b/drivers/iommu/apple-dart.c
> @@ -85,6 +85,62 @@
> #define DART_T8020_TTBR_ADDR_OFF 0
> #define DART_T8020_TTBR_SHIFT 12
>
> +/* T8110 registers */
> +
> +#define DART_T8110_PARAMS3 0x08
> +#define DART_T8110_PARAMS3_PA_WIDTH GENMASK(29, 24)
> +#define DART_T8110_PARAMS3_VA_WIDTH GENMASK(21, 16)
> +#define DART_T8110_PARAMS3_VER_MAJ GENMASK(15, 8)
> +#define DART_T8110_PARAMS3_VER_MIN GENMASK(7, 0)
> +
> +#define DART_T8110_PARAMS4 0x0c
> +#define DART_T8110_PARAMS4_NUM_CLIENTS GENMASK(24, 16)
> +#define DART_T8110_PARAMS4_NUM_SIDS GENMASK(8, 0)
> +
> +#define DART_T8110_TLB_CMD 0x80
> +#define DART_T8110_TLB_CMD_BUSY BIT(31)
> +#define DART_T8110_TLB_CMD_OP GENMASK(10, 8)
> +#define DART_T8110_TLB_CMD_OP_FLUSH_ALL 0
> +#define DART_T8110_TLB_CMD_OP_FLUSH_SID 1
> +#define DART_T8110_TLB_CMD_STREAM GENMASK(7, 0)
> +
> +#define DART_T8110_ERROR 0x100
> +#define DART_T8110_ERROR_STREAM GENMASK(27, 20)
> +#define DART_T8110_ERROR_CODE GENMASK(14, 0)
> +#define DART_T8110_ERROR_FLAG BIT(31)
> +
> +#define DART_T8110_ERROR_MASK 0x104
> +
> +#define DART_T8110_ERROR_READ_FAULT BIT(4)
> +#define DART_T8110_ERROR_WRITE_FAULT BIT(3)
> +#define DART_T8110_ERROR_NO_PTE BIT(3)
> +#define DART_T8110_ERROR_NO_PMD BIT(2)
> +#define DART_T8110_ERROR_NO_PGD BIT(1)
> +#define DART_T8110_ERROR_NO_TTBR BIT(0)
> +
> +#define DART_T8110_ERROR_ADDR_LO 0x170
> +#define DART_T8110_ERROR_ADDR_HI 0x174
> +
> +#define DART_T8110_PROTECT 0x200
> +#define DART_T8110_UNPROTECT 0x204
> +#define DART_T8110_PROTECT_LOCK 0x208
> +#define DART_T8110_PROTECT_TTBR_TCR BIT(0)

Do you have any more details on this registers? For the 8103 DART
we called it _CONFIG but I assume for the t8110 DART it can
actually lock different parts of the HW instead of just a global lock?

> +
> +#define DART_T8110_ENABLE_STREAMS 0xc00
> +#define DART_T8110_DISABLE_STREAMS 0xc20
> +
> +#define DART_T8110_TCR 0x1000
> +#define DART_T8110_TCR_REMAP GENMASK(11, 8)
> +#define DART_T8110_TCR_REMAP_EN BIT(7)
> +#define DART_T8110_TCR_BYPASS_DAPF BIT(2)
> +#define DART_T8110_TCR_BYPASS_DART BIT(1)
> +#define DART_T8110_TCR_TRANSLATE_ENABLE BIT(0)
> +
> +#define DART_T8110_TTBR 0x1400
> +#define DART_T8110_TTBR_VALID BIT(0)
> +#define DART_T8110_TTBR_ADDR_OFF 2
> +#define DART_T8110_TTBR_SHIFT 14
> +
> #define DART_TCR(dart, sid) ((dart)->hw->tcr + ((sid) << 2))
>
> #define DART_TTBR(dart, sid, idx) ((dart)->hw->ttbr + \
> @@ -93,7 +149,14 @@
>
> struct apple_dart_stream_map;
>
> +enum dart_type {

Minor nit: enum apple_dart_type to be consistent with the rest of the driver.

> + DART_T8020,
> + DART_T6000,
> + DART_T8110,
> +};
> +
> struct apple_dart_hw {
> + enum dart_type type;
> irqreturn_t (*irq_handler)(int irq, void *dev);
> int (*invalidate_tlb)(struct apple_dart_stream_map *stream_map);
>
> @@ -150,6 +213,8 @@ struct apple_dart {
>
> spinlock_t lock;
>
> + u32 ias;
> + u32 oas;
> u32 pgsize;
> u32 num_streams;
> u32 supports_bypass : 1;
> @@ -331,6 +396,44 @@ apple_dart_t8020_hw_stream_command(struct
> apple_dart_stream_map *stream_map,
> return 0;
> }
>
> +static int
> +apple_dart_t8110_hw_tlb_command(struct apple_dart_stream_map
> *stream_map,
> + u32 command)
> +{
> + struct apple_dart *dart = stream_map->dart;
> + unsigned long flags;
> + int ret = 0;
> + int sid;
> +
> + spin_lock_irqsave(&dart->lock, flags);
> +
> + for_each_set_bit(sid, stream_map->sidmap, dart->num_streams) {
> + u32 val = FIELD_PREP(DART_T8110_TLB_CMD_OP, command) |
> + FIELD_PREP(DART_T8110_TLB_CMD_STREAM, sid);
> + writel(val, dart->regs + DART_T8110_TLB_CMD);
> +
> + ret = readl_poll_timeout_atomic(
> + dart->regs + DART_T8110_TLB_CMD, val,
> + !(val & DART_T8110_TLB_CMD_BUSY), 1,
> + DART_STREAM_COMMAND_BUSY_TIMEOUT);
> +
> + if (ret)
> + break;
> +
> + }
> +
> + spin_unlock_irqrestore(&dart->lock, flags);
> +
> + if (ret) {
> + dev_err(stream_map->dart->dev,
> + "busy bit did not clear after command %x for stream %d\n",
> + command, sid);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int
> apple_dart_t8020_hw_invalidate_tlb(struct apple_dart_stream_map
> *stream_map)
> {
> @@ -338,6 +441,13 @@ apple_dart_t8020_hw_invalidate_tlb(struct
> apple_dart_stream_map *stream_map)
> stream_map, DART_T8020_STREAM_COMMAND_INVALIDATE);
> }
>
> +static int
> +apple_dart_t8110_hw_invalidate_tlb(struct apple_dart_stream_map *stream_map)
> +{
> + return apple_dart_t8110_hw_tlb_command(
> + stream_map, DART_T8110_TLB_CMD_OP_FLUSH_SID);
> +}
> +
> static int apple_dart_hw_reset(struct apple_dart *dart)
> {
> u32 config;
> @@ -364,6 +474,9 @@ static int apple_dart_hw_reset(struct apple_dart *dart)
> /* clear any pending errors before the interrupt is unmasked */
> writel(readl(dart->regs + dart->hw->error), dart->regs + dart->hw->error);
>
> + if (dart->hw->type == DART_T8110)
> + writel(0, dart->regs + DART_T8110_ERROR_MASK);
> +
> return dart->hw->invalidate_tlb(&stream_map);
> }
>
> @@ -479,8 +592,8 @@ static int apple_dart_finalize_domain(struct
> iommu_domain *domain,
>
> pgtbl_cfg = (struct io_pgtable_cfg){
> .pgsize_bitmap = dart->pgsize,
> - .ias = 32,
> - .oas = dart->hw->oas,
> + .ias = dart->ias,
> + .oas = dart->oas,
> .coherent_walk = 1,
> .iommu_dev = dart->dev,
> };
> @@ -494,7 +607,7 @@ static int apple_dart_finalize_domain(struct
> iommu_domain *domain,
>
> domain->pgsize_bitmap = pgtbl_cfg.pgsize_bitmap;
> domain->geometry.aperture_start = 0;
> - domain->geometry.aperture_end = DMA_BIT_MASK(32);
> + domain->geometry.aperture_end = DMA_BIT_MASK(dart->ias);
> domain->geometry.force_aperture = true;
>
> dart_domain->finalized = true;
> @@ -881,10 +994,49 @@ static irqreturn_t apple_dart_t8020_irq(int irq,
> void *dev)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t apple_dart_t8110_irq(int irq, void *dev)
> +{
> + struct apple_dart *dart = dev;
> + const char *fault_name = NULL;
> + u32 error = readl(dart->regs + DART_T8110_ERROR);
> + u32 error_code = FIELD_GET(DART_T8110_ERROR_CODE, error);
> + u32 addr_lo = readl(dart->regs + DART_T8110_ERROR_ADDR_LO);
> + u32 addr_hi = readl(dart->regs + DART_T8110_ERROR_ADDR_HI);
> + u64 addr = addr_lo | (((u64)addr_hi) << 32);
> + u8 stream_idx = FIELD_GET(DART_T8110_ERROR_STREAM, error);
> +
> + if (!(error & DART_T8110_ERROR_FLAG))
> + return IRQ_NONE;
> +
> + /* there should only be a single bit set but let's use == to be sure */
> + if (error_code == DART_T8110_ERROR_READ_FAULT)
> + fault_name = "READ FAULT";
> + else if (error_code == DART_T8110_ERROR_WRITE_FAULT)
> + fault_name = "WRITE FAULT";
> + else if (error_code == DART_T8110_ERROR_NO_PTE)
> + fault_name = "NO PTE FOR IOVA";
> + else if (error_code == DART_T8110_ERROR_NO_PMD)
> + fault_name = "NO PMD FOR IOVA";
> + else if (error_code == DART_T8110_ERROR_NO_PGD)
> + fault_name = "NO PGD FOR IOVA";
> + else if (error_code == DART_T8110_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_T8110_ERROR);
> + return IRQ_HANDLED;
> +}
> +
> static int apple_dart_probe(struct platform_device *pdev)
> {
> int ret;
> - u32 dart_params[2];
> + u32 dart_params[4];
> struct resource *res;
> struct apple_dart *dart;
> struct device *dev = &pdev->dev;
> @@ -924,7 +1076,22 @@ static int apple_dart_probe(struct platform_device *pdev)
> dart->pgsize = 1 << FIELD_GET(DART_PARAMS1_PAGE_SHIFT, dart_params[0]);
> dart->supports_bypass = dart_params[1] & DART_PARAMS2_BYPASS_SUPPORT;
>
> - dart->num_streams = dart->hw->max_sid_count;
> + switch (dart->hw->type) {
> + case DART_T8020:
> + case DART_T6000:
> + dart->ias = 32;
> + dart->oas = dart->hw->oas;
> + dart->num_streams = dart->hw->max_sid_count;
> + break;
> +
> + case DART_T8110:
> + dart_params[2] = readl(dart->regs + DART_T8110_PARAMS3);
> + dart_params[3] = readl(dart->regs + DART_T8110_PARAMS4);
> + dart->ias = FIELD_GET(DART_T8110_PARAMS3_VA_WIDTH, dart_params[2]);
> + dart->oas = FIELD_GET(DART_T8110_PARAMS3_PA_WIDTH, dart_params[2]);
> + dart->num_streams = FIELD_GET(DART_T8110_PARAMS4_NUM_SIDS, dart_params[3]);
> + break;
> + }
>
> if (dart->num_streams > DART_MAX_STREAMS) {
> dev_err(&pdev->dev, "Too many streams (%d > %d)\n",
> @@ -987,6 +1154,7 @@ static int apple_dart_remove(struct platform_device *pdev)
> }
>
> static const struct apple_dart_hw apple_dart_hw_t8103 = {
> + .type = DART_T8020,
> .irq_handler = apple_dart_t8020_irq,
> .invalidate_tlb = apple_dart_t8020_hw_invalidate_tlb,
> .oas = 36,
> @@ -1011,6 +1179,7 @@ static const struct apple_dart_hw apple_dart_hw_t8103 = {
> .ttbr_count = 4,
> };
> static const struct apple_dart_hw apple_dart_hw_t6000 = {
> + .type = DART_T6000,
> .irq_handler = apple_dart_t8020_irq,
> .invalidate_tlb = apple_dart_t8020_hw_invalidate_tlb,
> .oas = 42,
> @@ -1035,6 +1204,32 @@ static const struct apple_dart_hw apple_dart_hw_t6000 = {
> .ttbr_count = 4,
> };
>
> +static const struct apple_dart_hw apple_dart_hw_t8110 = {
> + .type = DART_T8110,
> + .irq_handler = apple_dart_t8110_irq,
> + .invalidate_tlb = apple_dart_t8110_hw_invalidate_tlb,
> + .fmt = APPLE_DART2,
> + .max_sid_count = 256,
> +
> + .enable_streams = DART_T8110_ENABLE_STREAMS,
> + .disable_streams = DART_T8110_DISABLE_STREAMS,
> + .lock = DART_T8110_PROTECT,
> + .lock_bit = DART_T8110_PROTECT_TTBR_TCR,
> +
> + .error = DART_T8110_ERROR,
> +
> + .tcr = DART_T8110_TCR,
> + .tcr_enabled = DART_T8110_TCR_TRANSLATE_ENABLE,
> + .tcr_disabled = 0,
> + .tcr_bypass = DART_T8110_TCR_BYPASS_DAPF | DART_T8110_TCR_BYPASS_DART,
> +
> + .ttbr = DART_T8110_TTBR,
> + .ttbr_valid = DART_T8110_TTBR_VALID,
> + .ttbr_addr_off = DART_T8110_TTBR_ADDR_OFF,
> + .ttbr_shift = DART_T8110_TTBR_SHIFT,
> + .ttbr_count = 1,
> +};
> +
> static __maybe_unused int apple_dart_suspend(struct device *dev)
> {
> struct apple_dart *dart = dev_get_drvdata(dev);
> @@ -1076,6 +1271,7 @@ DEFINE_SIMPLE_DEV_PM_OPS(apple_dart_pm_ops,
> apple_dart_suspend, apple_dart_resum
>
> static const struct of_device_id apple_dart_of_match[] = {
> { .compatible = "apple,t8103-dart", .data = &apple_dart_hw_t8103 },
> + { .compatible = "apple,t8110-dart", .data = &apple_dart_hw_t8110 },
> { .compatible = "apple,t6000-dart", .data = &apple_dart_hw_t6000 },
> {},
> };
> --
> 2.35.1