--- /dev/null
+/*
+ * 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/slab.h>
+#include <linux/errno.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/dmi.h>
+
+#include "nhi.h"
+#include "nhi_regs.h"
+
+#define RING_TYPE(ring) ((ring)->is_tx ? "TX ring" : "RX ring")
+
+
+static int ring_interrupt_index(struct tb_ring *ring)
+{
+ int bit = ring->hop;
+ if (!ring->is_tx)
+ bit += ring->nhi->hop_count;
+ return bit;
+}
+
+/**
+ * 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;
+ int bit = ring_interrupt_index(ring) & 31;
+ int mask = 1 << bit;
+ u32 old, new;
+ 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);
+}
+
+/**
+ * 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);
+}
+
+/* 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_iowrite16desc(struct tb_ring *ring, u32 value, u32 offset)
+{
+ iowrite16(value, ring_desc_base(ring) + offset);
+}
+
+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;
+ 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);
+ }
+}
+
+/**
+ * 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);
+ }
+}
+
+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;
+}
+
+static struct tb_ring *ring_alloc(struct tb_nhi *nhi, u32 hop, int size,
+ bool transmit)
+{
+ 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->head = 0;
+ ring->tail = 0;
+ ring->running = false;
+ 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;
+}
+
+struct tb_ring *ring_alloc_tx(struct tb_nhi *nhi, int hop, int size)
+{
+ return ring_alloc(nhi, hop, size, true);
+}
+
+struct tb_ring *ring_alloc_rx(struct tb_nhi *nhi, int hop, int size)
+{
+ return ring_alloc(nhi, hop, size, false);
+}
+
+/**
+ * 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->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);
+}
+
+
+/**
+ * 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->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);
+}
+
+/*
+ * 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);
+ }
+
+ dma_free_coherent(&ring->nhi->pdev->dev,
+ ring->size * sizeof(*ring->descriptors),
+ ring->descriptors, ring->descriptors_dma);
+
+ ring->descriptors = 0;
+ 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 and ring_stop). Wait for it to finish before
+ * freeing the ring.
+ */
+ flush_work(&ring->work);
+ mutex_destroy(&ring->lock);
+ kfree(ring);
+}
+
+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(&nhi->pdev->dev,
+ "got interrupt for inactive %s ring %d\n",
+ type ? "RX" : "TX",
+ hop);
+ continue;
+ }
+ /* we do not check ring->running, this is done in ring->work */
+ schedule_work(&ring->work);
+ }
+ mutex_unlock(&nhi->lock);
+}
+
+static irqreturn_t nhi_msi(int irq, void *data)
+{
+ struct tb_nhi *nhi = data;
+ schedule_work(&nhi->interrupt_work);
+ return IRQ_HANDLED;
+}
+
+static void nhi_shutdown(struct tb_nhi *nhi)
+{
+ int i;
+ dev_info(&nhi->pdev->dev, "shutdown\n");
+
+ for (i = 0; i < nhi->hop_count; i++) {
+ if (nhi->tx_rings[i])
+ dev_WARN(&nhi->pdev->dev,
+ "TX ring %d is still active\n", i);
+ if (nhi->rx_rings[i])
+ dev_WARN(&nhi->pdev->dev,
+ "RX ring %d is still active\n", i);
+ }
+ nhi_disable_interrupts(nhi);
+ /*
+ * We have to release the irq before calling flush_work. Otherwise an
+ * already executing IRQ handler could call schedule_work again.
+ */
+ devm_free_irq(&nhi->pdev->dev, nhi->pdev->irq, nhi);
+ flush_work(&nhi->interrupt_work);
+ mutex_destroy(&nhi->lock);
+}
+
+static int nhi_probe(struct pci_dev *pdev, const struct pci_device_id *id)
+{
+ struct tb_nhi *nhi;
+ int res;
+
+ res = pcim_enable_device(pdev);
+ if (res) {
+ dev_err(&pdev->dev, "cannot enable PCI device, aborting\n");
+ return res;
+ }
+
+ res = pci_enable_msi(pdev);
+ if (res) {
+ dev_err(&pdev->dev, "cannot enable MSI, aborting\n");
+ return res;
+ }
+
+ res = pcim_iomap_regions(pdev, 1 << 0, "thunderbolt");
+ if (res) {
+ dev_err(&pdev->dev, "cannot obtain PCI resources, aborting\n");
+ return res;
+ }
+
+ nhi = devm_kzalloc(&pdev->dev, sizeof(*nhi), GFP_KERNEL);
+ if (!nhi)
+ return -ENOMEM;
+
+ nhi->pdev = pdev;
+ /* cannot fail - table is allocated bin pcim_iomap_regions */
+ nhi->iobase = pcim_iomap_table(pdev)[0];
+ nhi->hop_count = ioread32(nhi->iobase + REG_HOP_COUNT) & 0x3ff;
+ if (nhi->hop_count != 12)
+ dev_warn(&pdev->dev, "unexpected hop count: %d\n",
+ nhi->hop_count);
+ INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
+
+ nhi->tx_rings = devm_kzalloc(&pdev->dev,
+ nhi->hop_count * sizeof(struct tb_ring),
+ GFP_KERNEL);
+ nhi->rx_rings = devm_kzalloc(&pdev->dev,
+ nhi->hop_count * sizeof(struct tb_ring),
+ GFP_KERNEL);
+ if (!nhi->tx_rings || !nhi->rx_rings)
+ return -ENOMEM;
+
+ nhi_disable_interrupts(nhi); /* In case someone left them on. */
+ res = devm_request_irq(&pdev->dev, pdev->irq, nhi_msi,
+ IRQF_NO_SUSPEND, /* must work during _noirq */
+ "thunderbolt", nhi);
+ if (res) {
+ dev_err(&pdev->dev, "request_irq failed, aborting\n");
+ return res;
+ }
+
+ mutex_init(&nhi->lock);
+
+ pci_set_master(pdev);
+
+ /* magic value - clock related? */
+ iowrite32(3906250 / 10000, nhi->iobase + 0x38c00);
+
+ pci_set_drvdata(pdev, nhi);
+
+ return 0;
+}
+
+static void nhi_remove(struct pci_dev *pdev)
+{
+ struct tb_nhi *nhi = pci_get_drvdata(pdev);
+ nhi_shutdown(nhi);
+}
+
+struct pci_device_id nhi_ids[] = {
+ /*
+ * We have to specify class, the TB bridges use the same device and
+ * vendor (sub)id.
+ */
+ {
+ .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
+ .vendor = PCI_VENDOR_ID_INTEL, .device = 0x1547,
+ .subvendor = 0x2222, .subdevice = 0x1111,
+ },
+ {
+ .class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
+ .vendor = PCI_VENDOR_ID_INTEL, .device = 0x156c,
+ .subvendor = 0x2222, .subdevice = 0x1111,
+ },
+ { 0,}
+};
+
+MODULE_DEVICE_TABLE(pci, nhi_ids);
+MODULE_LICENSE("GPL");
+
+static struct pci_driver nhi_driver = {
+ .name = "thunderbolt",
+ .id_table = nhi_ids,
+ .probe = nhi_probe,
+ .remove = nhi_remove,
+};
+
+static int __init nhi_init(void)
+{
+ if (!dmi_match(DMI_BOARD_VENDOR, "Apple Inc."))
+ return -ENOSYS;
+ return pci_register_driver(&nhi_driver);
+}
+
+static void __exit nhi_unload(void)
+{
+ pci_unregister_driver(&nhi_driver);
+}
+
+module_init(nhi_init);
+module_exit(nhi_unload);
projects / users / hch / dma-mapping.git / commitdiff