/*
* 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/dmi.h>
#include "nhi.h"
#include "nhi_regs.h"
#include "tb.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 * 4;
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 = 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 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 int nhi_suspend_noirq(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct tb *tb = pci_get_drvdata(pdev);
thunderbolt_suspend(tb);
return 0;
}
static int nhi_resume_noirq(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct tb *tb = pci_get_drvdata(pdev);
thunderbolt_resume(tb);
return 0;
}
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;
struct tb *tb;
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 && nhi->hop_count != 32)
dev_warn(&pdev->dev, "unexpected hop count: %d\n",
nhi->hop_count);
INIT_WORK(&nhi->interrupt_work, nhi_interrupt_work);
nhi->tx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
sizeof(*nhi->tx_rings), GFP_KERNEL);
nhi->rx_rings = devm_kcalloc(&pdev->dev, nhi->hop_count,
sizeof(*nhi->rx_rings), 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);
dev_info(&nhi->pdev->dev, "NHI initialized, starting thunderbolt\n");
tb = thunderbolt_alloc_and_start(nhi);
if (!tb) {
/*
* At this point the RX/TX rings might already have been
* activated. Do a proper shutdown.
*/
nhi_shutdown(nhi);
return -EIO;
}
pci_set_drvdata(pdev, tb);
return 0;
}
static void nhi_remove(struct pci_dev *pdev)
{
struct tb *tb = pci_get_drvdata(pdev);
struct tb_nhi *nhi = tb->nhi;
thunderbolt_shutdown_and_free(tb);
nhi_shutdown(nhi);
}
/*
* 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.
*/
static const struct dev_pm_ops nhi_pm_ops = {
.suspend_noirq = nhi_suspend_noirq,
.resume_noirq = nhi_resume_noirq,
.freeze_noirq = nhi_suspend_noirq, /*
* we just disable hotplug, the
* pci-tunnels stay alive.
*/
.restore_noirq = nhi_resume_noirq,
};
static struct pci_device_id nhi_ids[] = {
/*
* We have to specify class, the TB bridges use the same device and
* vendor (sub)id on gen 1 and gen 2 controllers.
*/
{
.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
.vendor = PCI_VENDOR_ID_INTEL,
.device = PCI_DEVICE_ID_INTEL_LIGHT_RIDGE,
.subvendor = 0x2222, .subdevice = 0x1111,
},
{
.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
.vendor = PCI_VENDOR_ID_INTEL,
.device = PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C,
.subvendor = 0x2222, .subdevice = 0x1111,
},
{
.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
.vendor = PCI_VENDOR_ID_INTEL,
.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_NHI,
.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
},
{
.class = PCI_CLASS_SYSTEM_OTHER << 8, .class_mask = ~0,
.vendor = PCI_VENDOR_ID_INTEL,
.device = PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_NHI,
.subvendor = PCI_ANY_ID, .subdevice = PCI_ANY_ID,
},
{ 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,
.driver.pm = &nhi_pm_ops,
};
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);
