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Release 4.14 drivers/thunderbolt/nhi.c

/*
 * Thunderbolt Cactus Ridge driver - NHI driver
 *
 * The NHI (native host interface) is the pci device that allows us to send and
 * receive frames from the thunderbolt bus.
 *
 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
 */

#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/delay.h>

#include "nhi.h"
#include "nhi_regs.h"
#include "tb.h"


#define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring")

/*
 * Minimal number of vectors when we use MSI-X. Two for control channel
 * Rx/Tx and the rest four are for cross domain DMA paths.
 */

#define MSIX_MIN_VECS		6

#define MSIX_MAX_VECS		16


#define NHI_MAILBOX_TIMEOUT	500 
/* ms */


static int ring_interrupt_index(struct tb_ring *ring) { int bit = ring->hop; if (!ring->is_tx) bit += ring->nhi->hop_count; return bit; }

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Andreas Noever36100.00%1100.00%
Total36100.00%1100.00%

/** * 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 reg = REG_RING_INTERRUPT_BASE + ring_interrupt_index(ring) / 32 * 4; int bit = ring_interrupt_index(ring) & 31; int mask = 1 << bit; u32 old, new; if (ring->irq > 0) { u32 step, shift, ivr, misc; void __iomem *ivr_base; int index; if (ring->is_tx) index = ring->hop; else index = ring->hop + ring->nhi->hop_count; /* * Ask the hardware to clear interrupt status bits automatically * since we already know which interrupt was triggered. */ misc = ioread32(ring->nhi->iobase + REG_DMA_MISC); if (!(misc & REG_DMA_MISC_INT_AUTO_CLEAR)) { misc |= REG_DMA_MISC_INT_AUTO_CLEAR; iowrite32(misc, 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); } old = ioread32(ring->nhi->iobase + reg); if (active) new = old | mask; else new = old & ~mask; dev_info(&ring->nhi->pdev->dev, "%s interrupt at register %#x bit %d (%#x -> %#x)\n", active ? "enabling" : "disabling", reg, bit, old, new); if (new == old) dev_WARN(&ring->nhi->pdev->dev, "interrupt for %s %d is already %s\n", RING_TYPE(ring), ring->hop, active ? "enabled" : "disabled"); iowrite32(new, ring->nhi->iobase + reg); }

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Mika Westerberg15950.32%133.33%
Andreas Noever15549.05%133.33%
Lukas Wunner20.63%133.33%
Total316100.00%3100.00%

/** * nhi_disable_interrupts() - disable interrupts for all rings * * Use only during init and shutdown. */
static void nhi_disable_interrupts(struct tb_nhi *nhi) { int i = 0; /* disable interrupts */ for (i = 0; i < RING_INTERRUPT_REG_COUNT(nhi); i++) iowrite32(0, nhi->iobase + REG_RING_INTERRUPT_BASE + 4 * i); /* clear interrupt status bits */ for (i = 0; i < RING_NOTIFY_REG_COUNT(nhi); i++) ioread32(nhi->iobase + REG_RING_NOTIFY_BASE + 4 * i); }

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Andreas Noever78100.00%1100.00%
Total78100.00%1100.00%

/* 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; }

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Andreas Noever45100.00%1100.00%
Total45100.00%1100.00%


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; }

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Andreas Noever45100.00%1100.00%
Total45100.00%1100.00%


static void ring_iowrite16desc(struct tb_ring *ring, u32 value, u32 offset) { iowrite16(value, ring_desc_base(ring) + offset); }

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Andreas Noever29100.00%1100.00%
Total29100.00%1100.00%


static void ring_iowrite32desc(struct tb_ring *ring, u32 value, u32 offset) { iowrite32(value, ring_desc_base(ring) + offset); }

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Andreas Noever29100.00%1100.00%
Total29100.00%1100.00%


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); }

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Andreas Noever45100.00%1100.00%
Total45100.00%1100.00%


static void ring_iowrite32options(struct tb_ring *ring, u32 value, u32 offset) { iowrite32(value, ring_options_base(ring) + offset); }

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Andreas Noever29100.00%1100.00%
Total29100.00%1100.00%


static bool ring_full(struct tb_ring *ring) { return ((ring->head + 1) % ring->size) == ring->tail; }

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Andreas Noever30100.00%1100.00%
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static bool ring_empty(struct tb_ring *ring) { return ring->head == ring->tail; }

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Andreas Noever20100.00%1100.00%
Total20100.00%1100.00%

/** * 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; 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 = RING_DESC_POSTED | RING_DESC_INTERRUPT; if (ring->is_tx) { descriptor->length = frame->size; descriptor->eof = frame->eof; descriptor->sof = frame->sof; } ring->head = (ring->head + 1) % ring->size; ring_iowrite16desc(ring, ring->head, ring->is_tx ? 10 : 8); } }

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Andreas Noever156100.00%1100.00%
Total156100.00%1100.00%

/** * 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; LIST_HEAD(done); mutex_lock(&ring->lock); 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; if (frame->sof != 0) dev_WARN(&ring->nhi->pdev->dev, "%s %d got unexpected SOF: %#x\n", RING_TYPE(ring), ring->hop, frame->sof); /* * known flags: * raw not enabled, interupt not set: 0x2=0010 * raw enabled: 0xa=1010 * raw not enabled: 0xb=1011 * partial frame (>MAX_FRAME_SIZE): 0xe=1110 */ if (frame->flags != 0xa) dev_WARN(&ring->nhi->pdev->dev, "%s %d got unexpected flags: %#x\n", RING_TYPE(ring), ring->hop, frame->flags); } ring->tail = (ring->tail + 1) % ring->size; } ring_write_descriptors(ring); invoke_callback: mutex_unlock(&ring->lock); /* allow callbacks to schedule new work */ 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); frame->callback(ring, frame, canceled); } }

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Andreas Noever368100.00%1100.00%
Total368100.00%1100.00%


int __ring_enqueue(struct tb_ring *ring, struct ring_frame *frame) { int ret = 0; mutex_lock(&ring->lock); if (ring->running) { list_add_tail(&frame->list, &ring->queue); ring_write_descriptors(ring); } else { ret = -ESHUTDOWN; } mutex_unlock(&ring->lock); return ret; }

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Andreas Noever5778.08%150.00%
Mika Westerberg1621.92%150.00%
Total73100.00%2100.00%


static irqreturn_t ring_msix(int irq, void *data) { struct tb_ring *ring = data; schedule_work(&ring->work); return IRQ_HANDLED; }

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Mika Westerberg31100.00%1100.00%
Total31100.00%1100.00%


static int ring_request_msix(struct tb_ring *ring, bool no_suspend) { struct tb_nhi *nhi = ring->nhi; unsigned long irqflags; int ret; if (!nhi->pdev->msix_enabled) return 0; ret = ida_simple_get(&nhi->msix_ida, 0, MSIX_MAX_VECS, GFP_KERNEL); if (ret < 0) return ret; ring->vector = ret; ring->irq = pci_irq_vector(ring->nhi->pdev, ring->vector); if (ring->irq < 0) return ring->irq; irqflags = no_suspend ? IRQF_NO_SUSPEND : 0; return request_irq(ring->irq, ring_msix, irqflags, "thunderbolt", ring); }

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Mika Westerberg127100.00%1100.00%
Total127100.00%1100.00%


static void ring_release_msix(struct tb_ring *ring) { if (ring->irq <= 0) return; free_irq(ring->irq, ring); ida_simple_remove(&ring->nhi->msix_ida, ring->vector); ring->vector = 0; ring->irq = 0; }

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Mika Westerberg5090.91%150.00%
Andreas Noever59.09%150.00%
Total55100.00%2100.00%


static struct tb_ring *ring_alloc(struct tb_nhi *nhi, u32 hop, int size, bool transmit, unsigned int flags) { struct tb_ring *ring = NULL; dev_info(&nhi->pdev->dev, "allocating %s ring %d of size %d\n", transmit ? "TX" : "RX", hop, size); mutex_lock(&nhi->lock); if (hop >= nhi->hop_count) { dev_WARN(&nhi->pdev->dev, "invalid hop: %d\n", hop); goto err; } if (transmit && nhi->tx_rings[hop]) { dev_WARN(&nhi->pdev->dev, "TX hop %d already allocated\n", hop); goto err; } else if (!transmit && nhi->rx_rings[hop]) { dev_WARN(&nhi->pdev->dev, "RX hop %d already allocated\n", hop); goto err; } ring = kzalloc(sizeof(*ring), GFP_KERNEL); if (!ring) goto err; mutex_init(&ring->lock); INIT_LIST_HEAD(&ring->queue); INIT_LIST_HEAD(&ring->in_flight); INIT_WORK(&ring->work, ring_work); ring->nhi = nhi; ring->hop = hop; ring->is_tx = transmit; ring->size = size; ring->flags = flags; ring->head = 0; ring->tail = 0; ring->running = false; if (ring_request_msix(ring, flags & RING_FLAG_NO_SUSPEND)) goto err; ring->descriptors = dma_alloc_coherent(&ring->nhi->pdev->dev, size * sizeof(*ring->descriptors), &ring->descriptors_dma, GFP_KERNEL | __GFP_ZERO); if (!ring->descriptors) goto err; if (transmit) nhi->tx_rings[hop] = ring; else nhi->rx_rings[hop] = ring; mutex_unlock(&nhi->lock); return ring; err: if (ring) mutex_destroy(&ring->lock); kfree(ring); mutex_unlock(&nhi->lock); return NULL; }

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Andreas Noever35493.65%150.00%
Mika Westerberg246.35%150.00%
Total378100.00%2100.00%


struct tb_ring *ring_alloc_tx(struct tb_nhi *nhi, int hop, int size, unsigned int flags) { return ring_alloc(nhi, hop, size, true, flags); }

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Andreas Noever3083.33%150.00%
Mika Westerberg616.67%150.00%
Total36100.00%2100.00%


struct tb_ring *ring_alloc_rx(struct tb_nhi *nhi, int hop, int size, unsigned int flags) { return ring_alloc(nhi, hop, size, false, flags); }

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Andreas Noever3083.33%150.00%
Mika Westerberg616.67%150.00%
Total36100.00%2100.00%

/** * ring_start() - enable a ring * * Must not be invoked in parallel with ring_stop(). */
void ring_start(struct tb_ring *ring) { mutex_lock(&ring->nhi->lock); mutex_lock(&ring->lock); if (ring->nhi->going_away) goto err; if (ring->running) { dev_WARN(&ring->nhi->pdev->dev, "ring already started\n"); goto err; } dev_info(&ring->nhi->pdev->dev, "starting %s %d\n", RING_TYPE(ring), ring->hop); ring_iowrite64desc(ring, ring->descriptors_dma, 0); if (ring->is_tx) { ring_iowrite32desc(ring, ring->size, 12); ring_iowrite32options(ring, 0, 4); /* time releated ? */ ring_iowrite32options(ring, RING_FLAG_ENABLE | RING_FLAG_RAW, 0); } else { ring_iowrite32desc(ring, (TB_FRAME_SIZE << 16) | ring->size, 12); ring_iowrite32options(ring, 0xffffffff, 4); /* SOF EOF mask */ ring_iowrite32options(ring, RING_FLAG_ENABLE | RING_FLAG_RAW, 0); } ring_interrupt_active(ring, true); ring->running = true; err: mutex_unlock(&ring->lock); mutex_unlock(&ring->nhi->lock); }

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Andreas Noever20194.81%150.00%
Mika Westerberg115.19%150.00%
Total212100.00%2100.00%

/** * ring_stop() - shutdown a ring * * Must not be invoked from a callback. * * This method will disable the ring. Further calls to ring_tx/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 ring_stop(struct tb_ring *ring) { mutex_lock(&ring->nhi->lock); mutex_lock(&ring->lock); dev_info(&ring->nhi->pdev->dev, "stopping %s %d\n", RING_TYPE(ring), ring->hop); if (ring->nhi->going_away) goto err; if (!ring->running) { dev_WARN(&ring->nhi->pdev->dev, "%s %d already stopped\n", RING_TYPE(ring), ring->hop); goto err; } ring_interrupt_active(ring, false); ring_iowrite32options(ring, 0, 0); ring_iowrite64desc(ring, 0, 0); ring_iowrite16desc(ring, 0, ring->is_tx ? 10 : 8); ring_iowrite32desc(ring, 0, 12); ring->head = 0; ring->tail = 0; ring->running = false; err: mutex_unlock(&ring->lock); mutex_unlock(&ring->nhi->lock); /* * schedule ring->work to invoke callbacks on all remaining frames. */ schedule_work(&ring->work); flush_work(&ring->work); }

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Andreas Noever19094.53%150.00%
Mika Westerberg115.47%150.00%
Total201100.00%2100.00%

/* * 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 ring_free(struct tb_ring *ring) { mutex_lock(&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->pdev->dev, "%s %d still running\n", RING_TYPE(ring), ring->hop); } ring_release_msix(ring); dma_free_coherent(&ring->nhi->pdev->dev, ring->size * sizeof(*ring->descriptors), ring->descriptors, ring->descriptors_dma); ring->descriptors = NULL; ring->descriptors_dma = 0; dev_info(&ring->nhi->pdev->dev, "freeing %s %d\n", RING_TYPE(ring), ring->hop); mutex_unlock(&ring->nhi->lock); /** * 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); mutex_destroy(&ring->lock); kfree(ring); }

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Andreas Noever18296.30%133.33%
Mika Westerberg63.17%133.33%
Sachin Kamat10.53%133.33%
Total189100.00%3100.00%

/** * 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. Returns %0 in * case of success and negative errno in case of failure. */
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; }

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Mika Westerberg146100.00%1100.00%
Total146100.00%1100.00%

/** * 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. */
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; }

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Mika Westerberg40100.00%1100.00%
Total40100.00%1100.00%


static 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; mutex_lock(&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->pdev->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