// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
#include <linux/module.h>
#include <linux/debugfs.h>
#include <linux/ntb.h>
#include <linux/pci.h>
#include <linux/radix-tree.h>
#include <linux/workqueue.h>
MODULE_LICENSE("Dual BSD/GPL");
MODULE_VERSION("0.1");
MODULE_AUTHOR("Logan Gunthorpe <[email protected]>");
MODULE_DESCRIPTION("Test for sending MSI interrupts over an NTB memory window");
static int num_irqs = 4;
module_param(num_irqs, int, 0644);
MODULE_PARM_DESC(num_irqs, "number of irqs to use");
struct ntb_msit_ctx {
struct ntb_dev *ntb;
struct dentry *dbgfs_dir;
struct work_struct setup_work;
struct ntb_msit_isr_ctx {
int irq_idx;
int irq_num;
int occurrences;
struct ntb_msit_ctx *nm;
struct ntb_msi_desc desc;
} *isr_ctx;
struct ntb_msit_peer {
struct ntb_msit_ctx *nm;
int pidx;
int num_irqs;
struct completion init_comp;
struct ntb_msi_desc *msi_desc;
} peers[];
};
static struct dentry *ntb_msit_dbgfs_topdir;
static irqreturn_t ntb_msit_isr(int irq, void *dev)
{
struct ntb_msit_isr_ctx *isr_ctx = dev;
struct ntb_msit_ctx *nm = isr_ctx->nm;
dev_dbg(&nm->ntb->dev, "Interrupt Occurred: %d",
isr_ctx->irq_idx);
isr_ctx->occurrences++;
return IRQ_HANDLED;
}
static void ntb_msit_setup_work(struct work_struct *work)
{
struct ntb_msit_ctx *nm = container_of(work, struct ntb_msit_ctx,
setup_work);
int irq_count = 0;
int irq;
int ret;
uintptr_t i;
ret = ntb_msi_setup_mws(nm->ntb);
if (ret) {
dev_err(&nm->ntb->dev, "Unable to setup MSI windows: %d\n",
ret);
return;
}
for (i = 0; i < num_irqs; i++) {
nm->isr_ctx[i].irq_idx = i;
nm->isr_ctx[i].nm = nm;
if (!nm->isr_ctx[i].irq_num) {
irq = ntbm_msi_request_irq(nm->ntb, ntb_msit_isr,
KBUILD_MODNAME,
&nm->isr_ctx[i],
&nm->isr_ctx[i].desc);
if (irq < 0)
break;
nm->isr_ctx[i].irq_num = irq;
}
ret = ntb_spad_write(nm->ntb, 2 * i + 1,
nm->isr_ctx[i].desc.addr_offset);
if (ret)
break;
ret = ntb_spad_write(nm->ntb, 2 * i + 2,
nm->isr_ctx[i].desc.data);
if (ret)
break;
irq_count++;
}
ntb_spad_write(nm->ntb, 0, irq_count);
ntb_peer_db_set(nm->ntb, BIT(ntb_port_number(nm->ntb)));
}
static void ntb_msit_desc_changed(void *ctx)
{
struct ntb_msit_ctx *nm = ctx;
int i;
dev_dbg(&nm->ntb->dev, "MSI Descriptors Changed\n");
for (i = 0; i < num_irqs; i++) {
ntb_spad_write(nm->ntb, 2 * i + 1,
nm->isr_ctx[i].desc.addr_offset);
ntb_spad_write(nm->ntb, 2 * i + 2,
nm->isr_ctx[i].desc.data);
}
ntb_peer_db_set(nm->ntb, BIT(ntb_port_number(nm->ntb)));
}
static void ntb_msit_link_event(void *ctx)
{
struct ntb_msit_ctx *nm = ctx;
if (!ntb_link_is_up(nm->ntb, NULL, NULL))
return;
schedule_work(&nm->setup_work);
}
static void ntb_msit_copy_peer_desc(struct ntb_msit_ctx *nm, int peer)
{
int i;
struct ntb_msi_desc *desc = nm->peers[peer].msi_desc;
int irq_count = nm->peers[peer].num_irqs;
for (i = 0; i < irq_count; i++) {
desc[i].addr_offset = ntb_peer_spad_read(nm->ntb, peer,
2 * i + 1);
desc[i].data = ntb_peer_spad_read(nm->ntb, peer, 2 * i + 2);
}
dev_info(&nm->ntb->dev, "Found %d interrupts on peer %d\n",
irq_count, peer);
complete_all(&nm->peers[peer].init_comp);
}
static void ntb_msit_db_event(void *ctx, int vec)
{
struct ntb_msit_ctx *nm = ctx;
struct ntb_msi_desc *desc;
u64 peer_mask = ntb_db_read(nm->ntb);
u32 irq_count;
int peer;
ntb_db_clear(nm->ntb, peer_mask);
for (peer = 0; peer < sizeof(peer_mask) * 8; peer++) {
if (!(peer_mask & BIT(peer)))
continue;
irq_count = ntb_peer_spad_read(nm->ntb, peer, 0);
if (irq_count == -1)
continue;
desc = kcalloc(irq_count, sizeof(*desc), GFP_ATOMIC);
if (!desc)
continue;
kfree(nm->peers[peer].msi_desc);
nm->peers[peer].msi_desc = desc;
nm->peers[peer].num_irqs = irq_count;
ntb_msit_copy_peer_desc(nm, peer);
}
}
static const struct ntb_ctx_ops ntb_msit_ops = {
.link_event = ntb_msit_link_event,
.db_event = ntb_msit_db_event,
};
static int ntb_msit_dbgfs_trigger(void *data, u64 idx)
{
struct ntb_msit_peer *peer = data;
if (idx >= peer->num_irqs)
return -EINVAL;
dev_dbg(&peer->nm->ntb->dev, "trigger irq %llu on peer %u\n",
idx, peer->pidx);
return ntb_msi_peer_trigger(peer->nm->ntb, peer->pidx,
&peer->msi_desc[idx]);
}
DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_trigger_fops, NULL,
ntb_msit_dbgfs_trigger, "%llu\n");
static int ntb_msit_dbgfs_port_get(void *data, u64 *port)
{
struct ntb_msit_peer *peer = data;
*port = ntb_peer_port_number(peer->nm->ntb, peer->pidx);
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_port_fops, ntb_msit_dbgfs_port_get,
NULL, "%llu\n");
static int ntb_msit_dbgfs_count_get(void *data, u64 *count)
{
struct ntb_msit_peer *peer = data;
*count = peer->num_irqs;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_count_fops, ntb_msit_dbgfs_count_get,
NULL, "%llu\n");
static int ntb_msit_dbgfs_ready_get(void *data, u64 *ready)
{
struct ntb_msit_peer *peer = data;
*ready = try_wait_for_completion(&peer->init_comp);
return 0;
}
static int ntb_msit_dbgfs_ready_set(void *data, u64 ready)
{
struct ntb_msit_peer *peer = data;
return wait_for_completion_interruptible(&peer->init_comp);
}
DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_ready_fops, ntb_msit_dbgfs_ready_get,
ntb_msit_dbgfs_ready_set, "%llu\n");
static int ntb_msit_dbgfs_occurrences_get(void *data, u64 *occurrences)
{
struct ntb_msit_isr_ctx *isr_ctx = data;
*occurrences = isr_ctx->occurrences;
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_occurrences_fops,
ntb_msit_dbgfs_occurrences_get,
NULL, "%llu\n");
static int ntb_msit_dbgfs_local_port_get(void *data, u64 *port)
{
struct ntb_msit_ctx *nm = data;
*port = ntb_port_number(nm->ntb);
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(ntb_msit_local_port_fops,
ntb_msit_dbgfs_local_port_get,
NULL, "%llu\n");
static void ntb_msit_create_dbgfs(struct ntb_msit_ctx *nm)
{
struct pci_dev *pdev = nm->ntb->pdev;
char buf[32];
int i;
struct dentry *peer_dir;
nm->dbgfs_dir = debugfs_create_dir(pci_name(pdev),
ntb_msit_dbgfs_topdir);
debugfs_create_file("port", 0400, nm->dbgfs_dir, nm,
&ntb_msit_local_port_fops);
for (i = 0; i < ntb_peer_port_count(nm->ntb); i++) {
nm->peers[i].pidx = i;
nm->peers[i].nm = nm;
init_completion(&nm->peers[i].init_comp);
snprintf(buf, sizeof(buf), "peer%d", i);
peer_dir = debugfs_create_dir(buf, nm->dbgfs_dir);
debugfs_create_file_unsafe("trigger", 0200, peer_dir,
&nm->peers[i],
&ntb_msit_trigger_fops);
debugfs_create_file_unsafe("port", 0400, peer_dir,
&nm->peers[i], &ntb_msit_port_fops);
debugfs_create_file_unsafe("count", 0400, peer_dir,
&nm->peers[i],
&ntb_msit_count_fops);
debugfs_create_file_unsafe("ready", 0600, peer_dir,
&nm->peers[i],
&ntb_msit_ready_fops);
}
for (i = 0; i < num_irqs; i++) {
snprintf(buf, sizeof(buf), "irq%d_occurrences", i);
debugfs_create_file_unsafe(buf, 0400, nm->dbgfs_dir,
&nm->isr_ctx[i],
&ntb_msit_occurrences_fops);
}
}
static void ntb_msit_remove_dbgfs(struct ntb_msit_ctx *nm)
{
debugfs_remove_recursive(nm->dbgfs_dir);
}
static int ntb_msit_probe(struct ntb_client *client, struct ntb_dev *ntb)
{
struct ntb_msit_ctx *nm;
int peers;
int ret;
peers = ntb_peer_port_count(ntb);
if (peers <= 0)
return -EINVAL;
if (ntb_spad_is_unsafe(ntb) || ntb_spad_count(ntb) < 2 * num_irqs + 1) {
dev_err(&ntb->dev, "NTB MSI test requires at least %d spads for %d irqs\n",
2 * num_irqs + 1, num_irqs);
return -EFAULT;
}
ret = ntb_spad_write(ntb, 0, -1);
if (ret) {
dev_err(&ntb->dev, "Unable to write spads: %d\n", ret);
return ret;
}
ret = ntb_db_clear_mask(ntb, GENMASK(peers - 1, 0));
if (ret) {
dev_err(&ntb->dev, "Unable to clear doorbell mask: %d\n", ret);
return ret;
}
ret = ntb_msi_init(ntb, ntb_msit_desc_changed);
if (ret) {
dev_err(&ntb->dev, "Unable to initialize MSI library: %d\n",
ret);
return ret;
}
nm = devm_kzalloc(&ntb->dev, struct_size(nm, peers, peers), GFP_KERNEL);
if (!nm)
return -ENOMEM;
nm->isr_ctx = devm_kcalloc(&ntb->dev, num_irqs, sizeof(*nm->isr_ctx),
GFP_KERNEL);
if (!nm->isr_ctx)
return -ENOMEM;
INIT_WORK(&nm->setup_work, ntb_msit_setup_work);
nm->ntb = ntb;
ntb_msit_create_dbgfs(nm);
ret = ntb_set_ctx(ntb, nm, &ntb_msit_ops);
if (ret)
goto remove_dbgfs;
if (!nm->isr_ctx) {
ret = -ENOMEM;
goto remove_dbgfs;
}
ntb_link_enable(ntb, NTB_SPEED_AUTO, NTB_WIDTH_AUTO);
return 0;
remove_dbgfs:
ntb_msit_remove_dbgfs(nm);
devm_kfree(&ntb->dev, nm->isr_ctx);
devm_kfree(&ntb->dev, nm);
return ret;
}
static void ntb_msit_remove(struct ntb_client *client, struct ntb_dev *ntb)
{
struct ntb_msit_ctx *nm = ntb->ctx;
int i;
ntb_link_disable(ntb);
ntb_db_set_mask(ntb, ntb_db_valid_mask(ntb));
ntb_msi_clear_mws(ntb);
for (i = 0; i < ntb_peer_port_count(ntb); i++)
kfree(nm->peers[i].msi_desc);
ntb_clear_ctx(ntb);
ntb_msit_remove_dbgfs(nm);
}
static struct ntb_client ntb_msit_client = {
.ops = {
.probe = ntb_msit_probe,
.remove = ntb_msit_remove
}
};
static int __init ntb_msit_init(void)
{
int ret;
if (debugfs_initialized())
ntb_msit_dbgfs_topdir = debugfs_create_dir(KBUILD_MODNAME,
NULL);
ret = ntb_register_client(&ntb_msit_client);
if (ret)
debugfs_remove_recursive(ntb_msit_dbgfs_topdir);
return ret;
}
module_init(ntb_msit_init);
static void __exit ntb_msit_exit(void)
{
ntb_unregister_client(&ntb_msit_client);
debugfs_remove_recursive(ntb_msit_dbgfs_topdir);
}
module_exit(ntb_msit_exit);