diff options
| author | Jinke Han <jinkehan@didiglobal.com> | 2026-09-08 15:37:42 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2026-09-17 09:48:42 +0200 |
| commit | a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 (patch) | |
| tree | 73fef824f9a846cf935869d0dbc5070ef6e2f741 /drivers/thunderbolt/nhi.c | |
| download | linux-stable-a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255.tar.gz linux-stable-a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255.zip | |
x86/kprobes: Fix crash when probing CS CALL instructionsgrafted
When using eBPF to probe CS CALL instructions within a function,
a crash can be triggered.
The eBPF tool probes offset 257 of the __hrtimer_run_queues()
function:
<__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1)
<__hrtimer_run_queues+254>: mov %r14,%rdi
<__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12>
<__hrtimer_run_queues+263>: mov %eax,%r12d
<__hrtimer_run_queues+266>: xchg %ax,%ax
<__hrtimer_run_queues+268>: mov %r13,%rdi
Which triggers this crash:
BUG: unable to handle page fault for address: 00000000000f41c9
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0
Oops: 0002 [#1] SMP NOPTI
CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P
RIP: 0010:__hrtimer_run_queues+0x106/0x230
Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is
at the 6th byte of the above CS CALL instruction. Since the CS CALL
instruction occupies 6 bytes, the exception occurred in the middle of that
call instruction.
The root cause is that when using eBPF tools to probe in the middle of a
function, a kprobe with INT3 is used as the underlying implementation.
During single-step emulation of the original CALL instruction,
int3_emulate_call() assumes that the probed CALL instruction is 5 bytes
long. However, the actual CS-prefixed CALL instruction occupies 6 bytes,
so it constructs an incorrect exception return address. When the CPU
returns from the kprobe handler, the next instruction to be executed is at
the address of the last byte of that CS CALL instruction. Coincidentally,
starting from that address, the CPU fetches and decodes a completely
different instruction, which ultimately triggers a kernel crash.
Fix the issue by using the actual instruction length obtained from
the instruction decoder when constructing the exception return
address, rather than relying on the hardcoded CALL_INSN_SIZE macro.
[ mingo: Refined the changelog ]
Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step")
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Jinke Han <jinkehan@didiglobal.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000
Diffstat (limited to 'drivers/thunderbolt/nhi.c')
| -rw-r--r-- | drivers/thunderbolt/nhi.c | 1324 |
1 files changed, 1324 insertions, 0 deletions
diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c new file mode 100644 index 000000000..5809809f6 --- /dev/null +++ b/drivers/thunderbolt/nhi.c @@ -0,0 +1,1324 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Thunderbolt driver - NHI driver + * + * The NHI (native host interface) is the device that allows us to send and + * receive frames from the thunderbolt bus. + * + * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> + * Copyright (C) 2018, Intel Corporation + */ + +#include <linux/pm_runtime.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/iommu.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/property.h> +#include <linux/string_choices.h> +#include <linux/string_helpers.h> + +#include "nhi.h" +#include "nhi_regs.h" +#include "tb.h" + +#define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring") + +#define RING_FIRST_USABLE_HOPID 1 +/* + * Used with QUIRK_E2E to specify an unused HopID the Rx credits are + * transferred. + */ +#define RING_E2E_RESERVED_HOPID RING_FIRST_USABLE_HOPID + +#define NHI_MAILBOX_TIMEOUT 500 /* ms */ + +static bool host_reset = true; +module_param(host_reset, bool, 0444); +MODULE_PARM_DESC(host_reset, "reset USB4 host router (default: true)"); + +static int ring_interrupt_index(const struct tb_ring *ring) +{ + int bit = ring->hop; + if (!ring->is_tx) + bit += ring->nhi->hop_count; + return bit; +} + +static void nhi_mask_interrupt(struct tb_nhi *nhi, int mask, int ring) +{ + if (nhi->quirks & QUIRK_AUTO_CLEAR_INT) { + u32 val; + + val = ioread32(nhi->iobase + REG_RING_INTERRUPT_BASE + ring); + iowrite32(val & ~mask, nhi->iobase + REG_RING_INTERRUPT_BASE + ring); + } else { + iowrite32(mask, nhi->iobase + REG_RING_INTERRUPT_MASK_CLEAR_BASE + ring); + } +} + +static void nhi_clear_interrupt(struct tb_nhi *nhi, int ring) +{ + if (nhi->quirks & QUIRK_AUTO_CLEAR_INT) + ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + ring); + else + iowrite32(~0, nhi->iobase + REG_RING_INT_CLEAR + ring); +} + +/* + * ring_interrupt_active() - activate/deactivate interrupts for a single ring + * + * ring->nhi->lock must be held. + */ +static void ring_interrupt_active(struct tb_ring *ring, bool active) +{ + int index = ring_interrupt_index(ring) / 32 * 4; + int reg = REG_RING_INTERRUPT_BASE + index; + int interrupt_bit = ring_interrupt_index(ring) & 31; + int mask = 1 << interrupt_bit; + u32 old, new; + + if (ring->irq > 0) { + u32 step, shift, ivr, misc, itr; + void __iomem *ivr_base; + int auto_clear_bit; + int index; + + if (ring->is_tx) + index = ring->hop; + else + index = ring->hop + ring->nhi->hop_count; + + /* + * Intel routers support a bit that isn't part of + * the USB4 spec to ask the hardware to clear + * interrupt status bits automatically since + * we already know which interrupt was triggered. + * + * Other routers explicitly disable auto-clear + * to prevent conditions that may occur where two + * MSIX interrupts are simultaneously active and + * reading the register clears both of them. + */ + misc = ioread32(ring->nhi->iobase + REG_DMA_MISC); + if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT) + auto_clear_bit = REG_DMA_MISC_INT_AUTO_CLEAR; + else + auto_clear_bit = REG_DMA_MISC_DISABLE_AUTO_CLEAR; + if (!(misc & auto_clear_bit)) + iowrite32(misc | auto_clear_bit, + ring->nhi->iobase + REG_DMA_MISC); + + ivr_base = ring->nhi->iobase + REG_INT_VEC_ALLOC_BASE; + step = index / REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS; + shift = index % REG_INT_VEC_ALLOC_REGS * REG_INT_VEC_ALLOC_BITS; + ivr = ioread32(ivr_base + step); + ivr &= ~(REG_INT_VEC_ALLOC_MASK << shift); + if (active) + ivr |= ring->vector << shift; + iowrite32(ivr, ivr_base + step); + + /* Throttling is specified in 256ns increments */ + itr = DIV_ROUND_UP(ring->interval_nsec, 256); + itr &= REG_INT_THROTTLING_RATE_INTERVAL_MASK; + iowrite32(itr, ring->nhi->iobase + REG_INT_THROTTLING_RATE + + ring->vector * 4); + } + + old = ioread32(ring->nhi->iobase + reg); + if (active) + new = old | mask; + else + new = old & ~mask; + + dev_dbg(ring->nhi->dev, + "%s interrupt at register %#x bit %d (%#x -> %#x)\n", + active ? "enabling" : "disabling", reg, interrupt_bit, old, new); + + if (new == old) + dev_WARN(ring->nhi->dev, "interrupt for %s %d is already %s\n", + RING_TYPE(ring), ring->hop, + str_enabled_disabled(active)); + + if (active) + iowrite32(new, ring->nhi->iobase + reg); + else + nhi_mask_interrupt(ring->nhi, mask, index); +} + +/* + * nhi_disable_interrupts() - disable interrupts for all rings + * + * Use only during init and shutdown. + */ +void nhi_disable_interrupts(struct tb_nhi *nhi) +{ + int i = 0; + /* disable interrupts */ + for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++) + nhi_mask_interrupt(nhi, ~0, 4 * i); + + /* clear interrupt status bits */ + for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++) + nhi_clear_interrupt(nhi, 4 * i); +} + +/* ring helper methods */ + +static void __iomem *ring_desc_base(struct tb_ring *ring) +{ + void __iomem *io = ring->nhi->iobase; + io += ring->is_tx ? REG_TX_RING_BASE : REG_RX_RING_BASE; + io += ring->hop * 16; + return io; +} + +static void __iomem *ring_options_base(struct tb_ring *ring) +{ + void __iomem *io = ring->nhi->iobase; + io += ring->is_tx ? REG_TX_OPTIONS_BASE : REG_RX_OPTIONS_BASE; + io += ring->hop * 32; + return io; +} + +static void ring_iowrite_cons(struct tb_ring *ring, u16 cons) +{ + /* + * The other 16-bits in the register is read-only and writes to it + * are ignored by the hardware so we can save one ioread32() by + * filling the read-only bits with zeroes. + */ + iowrite32(cons, ring_desc_base(ring) + 8); +} + +static void ring_iowrite_prod(struct tb_ring *ring, u16 prod) +{ + /* See ring_iowrite_cons() above for explanation */ + iowrite32(prod << 16, ring_desc_base(ring) + 8); +} + +static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset) +{ + iowrite32(value, ring_desc_base(ring) + offset); +} + +static void ring_iowrite64desc(struct tb_ring *ring, u64 value, u32 offset) +{ + iowrite32(value, ring_desc_base(ring) + offset); + iowrite32(value >> 32, ring_desc_base(ring) + offset + 4); +} + +static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset) +{ + iowrite32(value, ring_options_base(ring) + offset); +} + +static bool ring_full(struct tb_ring *ring) +{ + return ((ring->head + 1) % ring->size) == ring->tail; +} + +static bool ring_empty(struct tb_ring *ring) +{ + return ring->head == ring->tail; +} + +/* + * ring_write_descriptors() - post frames from ring->queue to the controller + * + * ring->lock is held. + */ +static void ring_write_descriptors(struct tb_ring *ring) +{ + struct ring_frame *frame, *n; + struct ring_desc *descriptor; + u32 flags; + + flags = RING_DESC_POSTED; + if (!(ring->flags & RING_FLAG_NO_INTERRUPT)) + flags |= RING_DESC_INTERRUPT; + + list_for_each_entry_safe(frame, n, &ring->queue, list) { + if (ring_full(ring)) + break; + list_move_tail(&frame->list, &ring->in_flight); + descriptor = &ring->descriptors[ring->head]; + descriptor->phys = frame->buffer_phy; + descriptor->time = 0; + descriptor->flags = flags; + if (ring->is_tx) { + descriptor->length = frame->size; + descriptor->eof = frame->eof; + descriptor->sof = frame->sof; + } + ring->head = (ring->head + 1) % ring->size; + if (ring->is_tx) + ring_iowrite_prod(ring, ring->head); + else + ring_iowrite_cons(ring, ring->head); + } +} + +/* + * ring_work() - progress completed frames + * + * If the ring is shutting down then all frames are marked as canceled and + * their callbacks are invoked. + * + * Otherwise we collect all completed frame from the ring buffer, write new + * frame to the ring buffer and invoke the callbacks for the completed frames. + */ +static void ring_work(struct work_struct *work) +{ + struct tb_ring *ring = container_of(work, typeof(*ring), work); + struct ring_frame *frame; + bool canceled = false; + unsigned long flags; + LIST_HEAD(done); + + spin_lock_irqsave(&ring->lock, flags); + + if (!ring->running) { + /* Move all frames to done and mark them as canceled. */ + list_splice_tail_init(&ring->in_flight, &done); + list_splice_tail_init(&ring->queue, &done); + canceled = true; + goto invoke_callback; + } + + while (!ring_empty(ring)) { + if (!(ring->descriptors[ring->tail].flags + & RING_DESC_COMPLETED)) + break; + frame = list_first_entry(&ring->in_flight, typeof(*frame), + list); + list_move_tail(&frame->list, &done); + if (!ring->is_tx) { + frame->size = ring->descriptors[ring->tail].length; + frame->eof = ring->descriptors[ring->tail].eof; + frame->sof = ring->descriptors[ring->tail].sof; + frame->flags = ring->descriptors[ring->tail].flags; + } + ring->tail = (ring->tail + 1) % ring->size; + } + ring_write_descriptors(ring); + +invoke_callback: + /* allow callbacks to schedule new work */ + spin_unlock_irqrestore(&ring->lock, flags); + while (!list_empty(&done)) { + frame = list_first_entry(&done, typeof(*frame), list); + /* + * The callback may reenqueue or delete frame. + * Do not hold on to it. + */ + list_del_init(&frame->list); + if (frame->callback) + frame->callback(ring, frame, canceled); + } + + wake_up(&ring->wait); +} + +int __tb_ring_enqueue(struct tb_ring *ring, struct ring_frame *frame) +{ + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&ring->lock, flags); + if (ring->running) { + list_add_tail(&frame->list, &ring->queue); + ring_write_descriptors(ring); + } else { + ret = -ESHUTDOWN; + } + spin_unlock_irqrestore(&ring->lock, flags); + return ret; +} +EXPORT_SYMBOL_GPL(__tb_ring_enqueue); + +/** + * tb_ring_poll() - Poll one completed frame from the ring + * @ring: Ring to poll + * + * This function can be called when @start_poll callback of the @ring + * has been called or the ring is created with %RING_FLAG_NO_INTERRUPT. + * It will read one completed frame from the ring and return it to the + * caller. + * + * Return: Pointer to &struct ring_frame, %NULL if there is no more + * completed frames. + */ +struct ring_frame *tb_ring_poll(struct tb_ring *ring) +{ + struct ring_frame *frame = NULL; + unsigned long flags; + + spin_lock_irqsave(&ring->lock, flags); + if (!ring->running) + goto unlock; + if (ring_empty(ring)) + goto unlock; + + if (ring->descriptors[ring->tail].flags & RING_DESC_COMPLETED) { + frame = list_first_entry(&ring->in_flight, typeof(*frame), + list); + list_del_init(&frame->list); + + if (!ring->is_tx) { + frame->size = ring->descriptors[ring->tail].length; + frame->eof = ring->descriptors[ring->tail].eof; + frame->sof = ring->descriptors[ring->tail].sof; + frame->flags = ring->descriptors[ring->tail].flags; + } + + ring->tail = (ring->tail + 1) % ring->size; + } + +unlock: + spin_unlock_irqrestore(&ring->lock, flags); + return frame; +} +EXPORT_SYMBOL_GPL(tb_ring_poll); + +static void __ring_interrupt_mask(struct tb_ring *ring, bool mask) +{ + int idx = ring_interrupt_index(ring); + int reg = REG_RING_INTERRUPT_BASE + idx / 32 * 4; + int bit = idx % 32; + u32 val; + + val = ioread32(ring->nhi->iobase + reg); + if (mask) + val &= ~BIT(bit); + else + val |= BIT(bit); + iowrite32(val, ring->nhi->iobase + reg); +} + +/* Both @nhi->lock and @ring->lock should be held */ +static void __ring_interrupt(struct tb_ring *ring) +{ + if (!ring->running) + return; + + if (ring->start_poll) { + __ring_interrupt_mask(ring, true); + ring->start_poll(ring->poll_data); + } else { + schedule_work(&ring->work); + } +} + +/** + * tb_ring_poll_complete() - Re-start interrupt for the ring + * @ring: Ring to re-start the interrupt + * + * This will re-start (unmask) the ring interrupt once the user is done + * with polling. + */ +void tb_ring_poll_complete(struct tb_ring *ring) +{ + unsigned long flags; + + spin_lock_irqsave(&ring->nhi->lock, flags); + spin_lock(&ring->lock); + if (ring->start_poll) + __ring_interrupt_mask(ring, false); + spin_unlock(&ring->lock); + spin_unlock_irqrestore(&ring->nhi->lock, flags); +} +EXPORT_SYMBOL_GPL(tb_ring_poll_complete); + +static void ring_clear_msix(const struct tb_ring *ring) +{ + int bit; + + if (ring->nhi->quirks & QUIRK_AUTO_CLEAR_INT) + return; + + bit = ring_interrupt_index(ring) & 31; + if (ring->is_tx) + iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR); + else + iowrite32(BIT(bit), ring->nhi->iobase + REG_RING_INT_CLEAR + + 4 * (ring->nhi->hop_count / 32)); +} + +irqreturn_t ring_msix(int irq, void *data) +{ + struct tb_ring *ring = data; + + spin_lock(&ring->nhi->lock); + ring_clear_msix(ring); + spin_lock(&ring->lock); + __ring_interrupt(ring); + spin_unlock(&ring->lock); + spin_unlock(&ring->nhi->lock); + + return IRQ_HANDLED; +} + +static int nhi_alloc_hop(struct tb_nhi *nhi, struct tb_ring *ring) +{ + unsigned int start_hop = RING_FIRST_USABLE_HOPID; + int ret = 0; + + if (nhi->quirks & QUIRK_E2E) { + start_hop = RING_FIRST_USABLE_HOPID + 1; + if (ring->flags & RING_FLAG_E2E && !ring->is_tx) { + dev_dbg(nhi->dev, "quirking E2E TX HopID %u -> %u\n", + ring->e2e_tx_hop, RING_E2E_RESERVED_HOPID); + ring->e2e_tx_hop = RING_E2E_RESERVED_HOPID; + } + } + + spin_lock_irq(&nhi->lock); + + if (ring->hop < 0) { + unsigned int i; + + /* + * Automatically allocate HopID from the non-reserved + * range 1 .. hop_count - 1. + */ + for (i = start_hop; i < nhi->hop_count; i++) { + if (ring->is_tx) { + if (!nhi->tx_rings[i]) { + ring->hop = i; + break; + } + } else { + if (!nhi->rx_rings[i]) { + ring->hop = i; + break; + } + } + } + } + + if (ring->hop > 0 && ring->hop < start_hop) { + dev_warn(nhi->dev, "invalid hop: %d\n", ring->hop); + ret = -EINVAL; + goto err_unlock; + } + if (ring->hop < 0 || ring->hop >= nhi->hop_count) { + dev_warn(nhi->dev, "invalid hop: %d\n", ring->hop); + ret = -EINVAL; + goto err_unlock; + } + if (ring->is_tx && nhi->tx_rings[ring->hop]) { + dev_warn(nhi->dev, "TX hop %d already allocated\n", + ring->hop); + ret = -EBUSY; + goto err_unlock; + } + if (!ring->is_tx && nhi->rx_rings[ring->hop]) { + dev_warn(nhi->dev, "RX hop %d already allocated\n", + ring->hop); + ret = -EBUSY; + goto err_unlock; + } + + if (ring->is_tx) + nhi->tx_rings[ring->hop] = ring; + else + nhi->rx_rings[ring->hop] = ring; + +err_unlock: + spin_unlock_irq(&nhi->lock); + + return ret; +} + +static struct tb_ring *tb_ring_alloc(struct tb_nhi *nhi, u32 hop, int size, + bool transmit, unsigned int flags, + int e2e_tx_hop, u16 sof_mask, u16 eof_mask, + void (*start_poll)(void *), + void *poll_data) +{ + struct tb_ring *ring = NULL; + + dev_dbg(nhi->dev, "allocating %s ring %d of size %d\n", + transmit ? "TX" : "RX", hop, size); + + if ((flags & RING_FLAG_NO_INTERRUPT) && start_poll) { + dev_WARN(nhi->dev, + "start_poll() and NO_INTERRUPT cannot be used at the same time\n"); + return NULL; + } + + ring = kzalloc_obj(*ring); + if (!ring) + return NULL; + + spin_lock_init(&ring->lock); + INIT_LIST_HEAD(&ring->queue); + INIT_LIST_HEAD(&ring->in_flight); + INIT_WORK(&ring->work, ring_work); + init_waitqueue_head(&ring->wait); + + ring->nhi = nhi; + ring->hop = hop; + ring->is_tx = transmit; + ring->size = size; + ring->flags = flags; + ring->e2e_tx_hop = e2e_tx_hop; + ring->sof_mask = sof_mask; + ring->eof_mask = eof_mask; + ring->head = 0; + ring->tail = 0; + ring->running = false; + ring->start_poll = start_poll; + ring->poll_data = poll_data; + + ring->descriptors = dma_alloc_coherent(ring->nhi->dev, + size * sizeof(*ring->descriptors), + &ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO); + if (!ring->descriptors) + goto err_free_ring; + + if (!(flags & RING_FLAG_NO_INTERRUPT) && nhi->ops->request_ring_irq) { + if (nhi->ops->request_ring_irq(ring, flags & RING_FLAG_NO_SUSPEND)) + goto err_free_descs; + } + + if (nhi_alloc_hop(nhi, ring)) + goto err_release_msix; + + return ring; + +err_release_msix: + if (nhi->ops->release_ring_irq) + nhi->ops->release_ring_irq(ring); +err_free_descs: + dma_free_coherent(ring->nhi->dev, + ring->size * sizeof(*ring->descriptors), + ring->descriptors, ring->descriptors_dma); +err_free_ring: + kfree(ring); + + return NULL; +} + +/** + * tb_ring_alloc_tx() - Allocate DMA ring for transmit + * @nhi: Pointer to the NHI the ring is to be allocated + * @hop: HopID (ring) to allocate + * @size: Number of entries in the ring + * @flags: Flags for the ring + * + * Return: Pointer to &struct tb_ring, %NULL otherwise. + */ +struct tb_ring *tb_ring_alloc_tx(struct tb_nhi *nhi, int hop, int size, + unsigned int flags) +{ + return tb_ring_alloc(nhi, hop, size, true, flags, 0, 0, 0, NULL, NULL); +} +EXPORT_SYMBOL_GPL(tb_ring_alloc_tx); + +/** + * tb_ring_alloc_rx() - Allocate DMA ring for receive + * @nhi: Pointer to the NHI the ring is to be allocated + * @hop: HopID (ring) to allocate. Pass %-1 for automatic allocation. + * @size: Number of entries in the ring + * @flags: Flags for the ring + * @e2e_tx_hop: Transmit HopID when E2E is enabled in @flags + * @sof_mask: Mask of PDF values that start a frame + * @eof_mask: Mask of PDF values that end a frame + * @start_poll: If not %NULL the ring will call this function when an + * interrupt is triggered and masked, instead of callback + * in each Rx frame. + * @poll_data: Optional data passed to @start_poll + * + * Return: Pointer to &struct tb_ring, %NULL otherwise. + */ +struct tb_ring *tb_ring_alloc_rx(struct tb_nhi *nhi, int hop, int size, + unsigned int flags, int e2e_tx_hop, + u16 sof_mask, u16 eof_mask, + void (*start_poll)(void *), void *poll_data) +{ + return tb_ring_alloc(nhi, hop, size, false, flags, e2e_tx_hop, sof_mask, eof_mask, + start_poll, poll_data); +} +EXPORT_SYMBOL_GPL(tb_ring_alloc_rx); + +/** + * tb_ring_start() - enable a ring + * @ring: Ring to start + * + * Must not be invoked in parallel with tb_ring_stop(). + */ +void tb_ring_start(struct tb_ring *ring) +{ + u16 frame_size; + u32 flags; + + spin_lock_irq(&ring->nhi->lock); + spin_lock(&ring->lock); + if (ring->nhi->going_away) + goto err; + if (ring->running) { + dev_WARN(ring->nhi->dev, "ring already started\n"); + goto err; + } + dev_dbg(ring->nhi->dev, "starting %s %d\n", + RING_TYPE(ring), ring->hop); + + if (ring->flags & RING_FLAG_FRAME) { + /* Means 4096 */ + frame_size = 0; + flags = RING_FLAG_ENABLE; + } else { + frame_size = TB_FRAME_SIZE; + flags = RING_FLAG_ENABLE | RING_FLAG_RAW; + } + + ring_iowrite64desc(ring, ring->descriptors_dma, 0); + if (ring->is_tx) { + ring_iowrite32desc(ring, ring->size, 12); + ring_iowrite32options(ring, 0, 4); + ring_iowrite32options(ring, flags, 0); + } else { + u32 sof_eof_mask = ring->sof_mask << 16 | ring->eof_mask; + + ring_iowrite32desc(ring, (frame_size << 16) | ring->size, 12); + ring_iowrite32options(ring, sof_eof_mask, 4); + ring_iowrite32options(ring, flags, 0); + } + + /* + * Now that the ring valid bit is set we can configure E2E if + * enabled for the ring. + */ + if (ring->flags & RING_FLAG_E2E) { + if (!ring->is_tx) { + u32 hop; + + hop = ring->e2e_tx_hop << REG_RX_OPTIONS_E2E_HOP_SHIFT; + hop &= REG_RX_OPTIONS_E2E_HOP_MASK; + flags |= hop; + + dev_dbg(ring->nhi->dev, + "enabling E2E for %s %d with TX HopID %d\n", + RING_TYPE(ring), ring->hop, ring->e2e_tx_hop); + } else { + dev_dbg(ring->nhi->dev, "enabling E2E for %s %d\n", + RING_TYPE(ring), ring->hop); + } + + flags |= RING_FLAG_E2E_FLOW_CONTROL; + ring_iowrite32options(ring, flags, 0); + } + + if (!(ring->flags & RING_FLAG_NO_INTERRUPT)) + ring_interrupt_active(ring, true); + ring->running = true; +err: + spin_unlock(&ring->lock); + spin_unlock_irq(&ring->nhi->lock); +} +EXPORT_SYMBOL_GPL(tb_ring_start); + +static bool tb_ring_empty(struct tb_ring *ring) +{ + guard(spinlock_irqsave)(&ring->lock); + return list_empty(&ring->in_flight); +} + +/** + * tb_ring_flush() - Waits for a ring to be empty + * @ring: Ring to wait + * @timeout_msec: Timeout in ms how long to wait. + * + * This can be called before stopping a ring to make sure all the frames + * submitted prior have been completed. + * + * Return: %true if the ring is empty now, %false otherwise. + */ +bool tb_ring_flush(struct tb_ring *ring, unsigned int timeout_msec) +{ + if (!wait_event_timeout(ring->wait, tb_ring_empty(ring), + msecs_to_jiffies(timeout_msec))) + return false; + return tb_ring_empty(ring); +} +EXPORT_SYMBOL_GPL(tb_ring_flush); + +/** + * tb_ring_stop() - shutdown a ring + * @ring: Ring to stop + * + * Must not be invoked from a callback. + * + * This method will disable the ring. Further calls to + * tb_ring_tx/tb_ring_rx will return -ESHUTDOWN until ring_stop has been + * called. + * + * All enqueued frames will be canceled and their callbacks will be executed + * with frame->canceled set to true (on the callback thread). This method + * returns only after all callback invocations have finished. + */ +void tb_ring_stop(struct tb_ring *ring) +{ + spin_lock_irq(&ring->nhi->lock); + spin_lock(&ring->lock); + dev_dbg(ring->nhi->dev, "stopping %s %d\n", + RING_TYPE(ring), ring->hop); + if (ring->nhi->going_away) + goto err; + if (!ring->running) { + dev_WARN(ring->nhi->dev, "%s %d already stopped\n", + RING_TYPE(ring), ring->hop); + goto err; + } + if (!(ring->flags & RING_FLAG_NO_INTERRUPT)) + ring_interrupt_active(ring, false); + + ring_iowrite32options(ring, 0, 0); + ring_iowrite64desc(ring, 0, 0); + ring_iowrite32desc(ring, 0, 8); + ring_iowrite32desc(ring, 0, 12); + ring->head = 0; + ring->tail = 0; + ring->running = false; + +err: + spin_unlock(&ring->lock); + spin_unlock_irq(&ring->nhi->lock); + + /* + * schedule ring->work to invoke callbacks on all remaining frames. + */ + schedule_work(&ring->work); + flush_work(&ring->work); +} +EXPORT_SYMBOL_GPL(tb_ring_stop); + +/* + * tb_ring_free() - free ring + * + * When this method returns all invocations of ring->callback will have + * finished. + * + * Ring must be stopped. + * + * Must NOT be called from ring_frame->callback! + */ +void tb_ring_free(struct tb_ring *ring) +{ + struct tb_nhi *nhi = ring->nhi; + + spin_lock_irq(&ring->nhi->lock); + /* + * Dissociate the ring from the NHI. This also ensures that + * nhi_interrupt_work cannot reschedule ring->work. + */ + if (ring->is_tx) + ring->nhi->tx_rings[ring->hop] = NULL; + else + ring->nhi->rx_rings[ring->hop] = NULL; + + if (ring->running) { + dev_WARN(ring->nhi->dev, "%s %d still running\n", + RING_TYPE(ring), ring->hop); + } + spin_unlock_irq(&ring->nhi->lock); + + if (nhi->ops->release_ring_irq) + nhi->ops->release_ring_irq(ring); + + dma_free_coherent(ring->nhi->dev, + ring->size * sizeof(*ring->descriptors), + ring->descriptors, ring->descriptors_dma); + + ring->descriptors = NULL; + ring->descriptors_dma = 0; + + + dev_dbg(ring->nhi->dev, "freeing %s %d\n", RING_TYPE(ring), + ring->hop); + + /* + * ring->work can no longer be scheduled (it is scheduled only + * by nhi_interrupt_work, ring_stop and ring_msix). Wait for it + * to finish before freeing the ring. + */ + flush_work(&ring->work); + kfree(ring); +} +EXPORT_SYMBOL_GPL(tb_ring_free); + +/** + * tb_ring_throttling() - Configure throttling for ring interrupt + * @ring: Ring to configure + * @interval_nsec: Interval counter for moderation (in ns), %0 disables + * + * Enables or disables ring interrupt throttling. The ring must be + * stopped for this to be called. Granularity is 256 ns. + * + * Return: %0 on success, negative errno otherwise. + */ +int tb_ring_throttling(struct tb_ring *ring, unsigned int interval_nsec) +{ + guard(spinlock_irqsave)(&ring->lock); + if (WARN_ON_ONCE(ring->running)) + return -EBUSY; + ring->interval_nsec = interval_nsec; + return 0; +} +EXPORT_SYMBOL_GPL(tb_ring_throttling); + +/** + * nhi_mailbox_cmd() - Send a command through NHI mailbox + * @nhi: Pointer to the NHI structure + * @cmd: Command to send + * @data: Data to be send with the command + * + * Sends mailbox command to the firmware running on NHI. + * + * Return: %0 on success, negative errno otherwise. + */ +int nhi_mailbox_cmd(struct tb_nhi *nhi, enum nhi_mailbox_cmd cmd, u32 data) +{ + ktime_t timeout; + u32 val; + + iowrite32(data, nhi->iobase + REG_INMAIL_DATA); + + val = ioread32(nhi->iobase + REG_INMAIL_CMD); + val &= ~(REG_INMAIL_CMD_MASK | REG_INMAIL_ERROR); + val |= REG_INMAIL_OP_REQUEST | cmd; + iowrite32(val, nhi->iobase + REG_INMAIL_CMD); + + timeout = ktime_add_ms(ktime_get(), NHI_MAILBOX_TIMEOUT); + do { + val = ioread32(nhi->iobase + REG_INMAIL_CMD); + if (!(val & REG_INMAIL_OP_REQUEST)) + break; + usleep_range(10, 20); + } while (ktime_before(ktime_get(), timeout)); + + if (val & REG_INMAIL_OP_REQUEST) + return -ETIMEDOUT; + if (val & REG_INMAIL_ERROR) + return -EIO; + + return 0; +} + +/** + * nhi_mailbox_mode() - Return current firmware operation mode + * @nhi: Pointer to the NHI structure + * + * The function reads current firmware operation mode using NHI mailbox + * registers and returns it to the caller. + * + * Return: &enum nhi_fw_mode. + */ +enum nhi_fw_mode nhi_mailbox_mode(struct tb_nhi *nhi) +{ + u32 val; + + val = ioread32(nhi->iobase + REG_OUTMAIL_CMD); + val &= REG_OUTMAIL_CMD_OPMODE_MASK; + val >>= REG_OUTMAIL_CMD_OPMODE_SHIFT; + + return (enum nhi_fw_mode)val; +} + +void nhi_interrupt_work(struct work_struct *work) +{ + struct tb_nhi *nhi = container_of(work, typeof(*nhi), interrupt_work); + int value = 0; /* Suppress uninitialized usage warning. */ + int bit; + int hop = -1; + int type = 0; /* current interrupt type 0: TX, 1: RX, 2: RX overflow */ + struct tb_ring *ring; + + spin_lock_irq(&nhi->lock); + + /* + * Starting at REG_RING_NOTIFY_BASE there are three status bitfields + * (TX, RX, RX overflow). We iterate over the bits and read a new + * dwords as required. The registers are cleared on read. + */ + for (bit = 0; bit < 3 * nhi->hop_count; bit++) { + if (bit % 32 == 0) + value = ioread32(nhi->iobase + + REG_RING_NOTIFY_BASE + + 4 * (bit / 32)); + if (++hop == nhi->hop_count) { + hop = 0; + type++; + } + if ((value & (1 << (bit % 32))) == 0) + continue; + if (type == 2) { + dev_warn(nhi->dev, "RX overflow for ring %d\n", hop); + continue; + } + if (type == 0) + ring = nhi->tx_rings[hop]; + else + ring = nhi->rx_rings[hop]; + if (ring == NULL) { + dev_warn(nhi->dev, + "got interrupt for inactive %s ring %d\n", + type ? "RX" : "TX", + hop); + continue; + } + + spin_lock(&ring->lock); + __ring_interrupt(ring); + spin_unlock(&ring->lock); + } + spin_unlock_irq(&nhi->lock); +} + +irqreturn_t nhi_msi(int irq, void *data) +{ + struct tb_nhi *nhi = data; + schedule_work(&nhi->interrupt_work); + return IRQ_HANDLED; +} + +static int __nhi_suspend_noirq(struct device *dev, bool wakeup) +{ + struct tb *tb = dev_get_drvdata(dev); + struct tb_nhi *nhi = tb->nhi; + int ret; + + ret = tb_domain_suspend_noirq(tb); + if (ret) + return ret; + + if (nhi->ops->suspend_noirq) { + ret = nhi->ops->suspend_noirq(tb->nhi, wakeup); + if (ret) + return ret; + } + + return 0; +} + +static int nhi_suspend_noirq(struct device *dev) +{ + return __nhi_suspend_noirq(dev, device_may_wakeup(dev)); +} + +static int nhi_freeze_noirq(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + + return tb_domain_freeze_noirq(tb); +} + +static int nhi_thaw_noirq(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + + return tb_domain_thaw_noirq(tb); +} + +static bool nhi_wake_supported(struct device *dev) +{ + u8 val; + + /* + * If power rails are sustainable for wakeup from S4 this + * property is set by the BIOS. + */ + if (!device_property_read_u8(dev, "WAKE_SUPPORTED", &val)) + return !!val; + + return true; +} + +static int nhi_poweroff_noirq(struct device *dev) +{ + bool wakeup; + + wakeup = device_may_wakeup(dev) && nhi_wake_supported(dev); + return __nhi_suspend_noirq(dev, wakeup); +} + +static int nhi_resume_noirq(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + struct tb_nhi *nhi = tb->nhi; + int ret; + + /* + * Check that the device is still there. It may be that the user + * unplugged last device which causes the host controller to go + * away on PCs. + */ + if ((nhi->ops->is_present && !nhi->ops->is_present(nhi))) { + nhi->going_away = true; + } else if (nhi->ops->resume_noirq) { + ret = nhi->ops->resume_noirq(nhi); + if (ret) + return ret; + } + + return tb_domain_resume_noirq(tb); +} + +static int nhi_suspend(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + + return tb_domain_suspend(tb); +} + +static void nhi_complete(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + + /* + * If we were runtime suspended when system suspend started, + * schedule runtime resume now. It should bring the domain back + * to functional state. + */ + if (pm_runtime_suspended(dev)) + pm_runtime_resume(dev); + else + tb_domain_complete(tb); +} + +static int nhi_runtime_suspend(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + struct tb_nhi *nhi = tb->nhi; + int ret; + + ret = tb_domain_runtime_suspend(tb); + if (ret) + return ret; + + if (nhi->ops->runtime_suspend) { + ret = nhi->ops->runtime_suspend(tb->nhi); + if (ret) + return ret; + } + return 0; +} + +static int nhi_runtime_resume(struct device *dev) +{ + struct tb *tb = dev_get_drvdata(dev); + struct tb_nhi *nhi = tb->nhi; + int ret; + + if (nhi->ops->runtime_resume) { + ret = nhi->ops->runtime_resume(nhi); + if (ret) + return ret; + } + + return tb_domain_runtime_resume(tb); +} + +void nhi_shutdown(struct tb_nhi *nhi) +{ + int i; + + dev_dbg(nhi->dev, "shutdown\n"); + + for (i = 0; i < nhi->hop_count; i++) { + if (nhi->tx_rings[i]) + dev_WARN(nhi->dev, + "TX ring %d is still active\n", i); + if (nhi->rx_rings[i]) + dev_WARN(nhi->dev, + "RX ring %d is still active\n", i); + } + nhi_disable_interrupts(nhi); + + if (nhi->ops->shutdown) + nhi->ops->shutdown(nhi); +} + +static void nhi_reset(struct tb_nhi *nhi) +{ + ktime_t timeout; + u32 val; + + val = ioread32(nhi->iobase + REG_CAPS); + /* Reset only v2 and later routers */ + if (FIELD_GET(REG_CAPS_VERSION_MASK, val) < REG_CAPS_VERSION_2) + return; + + if (!host_reset) { + dev_dbg(nhi->dev, "skipping host router reset\n"); + return; + } + + iowrite32(REG_RESET_HRR, nhi->iobase + REG_RESET); + msleep(100); + + timeout = ktime_add_ms(ktime_get(), 500); + do { + val = ioread32(nhi->iobase + REG_RESET); + if (!(val & REG_RESET_HRR)) { + dev_warn(nhi->dev, "host router reset successful\n"); + return; + } + usleep_range(10, 20); + } while (ktime_before(ktime_get(), timeout)); + + dev_warn(nhi->dev, "timeout resetting host router\n"); +} + +/** + * nhi_reset_interface() - Reset the host interface + * @nhi: Host interface to reset + * + * Brings the registers in the memory BAR back to their default state and + * clears the End-to-End Flow Control state. The caller is responsible for + * stopping the control channel over the reset because it clears the ring + * state as well. + */ +void nhi_reset_interface(struct tb_nhi *nhi) +{ + u32 val; + + val = ioread32(nhi->iobase + REG_CAPS); + /* Only v1 host interfaces implement the reset */ + if (FIELD_GET(REG_CAPS_VERSION_MASK, val) >= REG_CAPS_VERSION_2) + return; + + dev_dbg(nhi->dev, "issuing host interface reset\n"); + + iowrite32(REG_HOST_INTERFACE_RESET_RST, + nhi->iobase + REG_HOST_INTERFACE_RESET); + /* Wait for tHIReset (10 ms) to complete */ + usleep_range(10000, 20000); +} + +static struct tb *nhi_select_cm(struct tb_nhi *nhi) +{ + struct tb *tb; + + /* + * USB4 case is simple. If we got control of any of the + * capabilities, we use software CM. + */ + if (tb_acpi_is_native()) + return tb_probe(nhi); + + /* + * Either firmware based CM is running (we did not get control + * from the firmware) or this is pre-USB4 PC so try first + * firmware CM and then fallback to software CM. + */ + tb = icm_probe(nhi); + if (!tb) + tb = tb_probe(nhi); + + return tb; +} + +int nhi_probe(struct tb_nhi *nhi) +{ + struct device *dev = nhi->dev; + struct tb *tb; + int res; + + if (!nhi->ops) + return dev_err_probe(dev, -EINVAL, "NHI ops not set\n"); + + if (!nhi->ops->init_interrupts) + return dev_err_probe(dev, -EINVAL, "missing required NHI ops\n"); + + nhi->hop_count = ioread32(nhi->iobase + REG_CAPS) & 0x3ff; + dev_dbg(dev, "total paths: %d\n", nhi->hop_count); + + nhi->tx_rings = devm_kcalloc(dev, nhi->hop_count, + sizeof(*nhi->tx_rings), GFP_KERNEL); + nhi->rx_rings = devm_kcalloc(dev, nhi->hop_count, + sizeof(*nhi->rx_rings), GFP_KERNEL); + if (!nhi->tx_rings || !nhi->rx_rings) + return -ENOMEM; + + nhi_reset(nhi); + + /* In case someone left them on. */ + nhi_disable_interrupts(nhi); + + res = nhi->ops->init_interrupts(nhi); + if (res) + return dev_err_probe(dev, res, "cannot enable interrupts, aborting\n"); + + spin_lock_init(&nhi->lock); + + res = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64)); + if (res) + return dev_err_probe(dev, res, "failed to set DMA mask\n"); + + if (nhi->ops->init) { + res = nhi->ops->init(nhi); + if (res) + return dev_err_probe(dev, res, "NHI specific init failed\n"); + } + + init_completion(&nhi->domain_released); + + tb = nhi_select_cm(nhi); + if (!tb) + return dev_err_probe(dev, -ENODEV, + "failed to determine connection manager, aborting\n"); + + dev_dbg(dev, "NHI initialized, starting thunderbolt\n"); + + nhi->host_reset = host_reset; + + res = tb_domain_add(tb, host_reset); + if (res) { + /* + * At this point the RX/TX rings might already have been + * activated. Do a proper shutdown. + */ + tb_domain_put(tb); + wait_for_completion(&nhi->domain_released); + nhi_shutdown(nhi); + return dev_err_probe(dev, res, "failed to add domain\n"); + } + dev_set_drvdata(dev, tb); + + device_wakeup_enable(dev); + + pm_runtime_allow(dev); + pm_runtime_set_autosuspend_delay(dev, TB_AUTOSUSPEND_DELAY); + pm_runtime_use_autosuspend(dev); + pm_runtime_put_autosuspend(dev); + + return 0; +} + +/* + * The tunneled pci bridges are siblings of us. Use resume_noirq to reenable + * the tunnels asap. A corresponding pci quirk blocks the downstream bridges + * resume_noirq until we are done. + */ +const struct dev_pm_ops nhi_pm_ops = { + .suspend_noirq = nhi_suspend_noirq, + .resume_noirq = nhi_resume_noirq, + .freeze_noirq = nhi_freeze_noirq, /* + * we just disable hotplug, the + * pci-tunnels stay alive. + */ + .thaw_noirq = nhi_thaw_noirq, + .restore_noirq = nhi_resume_noirq, + .suspend = nhi_suspend, + .poweroff_noirq = nhi_poweroff_noirq, + .poweroff = nhi_suspend, + .complete = nhi_complete, + .runtime_suspend = nhi_runtime_suspend, + .runtime_resume = nhi_runtime_resume, +}; |
