kernel-aes67/drivers/dma/idxd/cdev.c

699 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/device.h>
#include <linux/sched/task.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/cdev.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/iommu.h>
#include <linux/highmem.h>
#include <uapi/linux/idxd.h>
#include <linux/xarray.h>
#include "registers.h"
#include "idxd.h"
struct idxd_cdev_context {
const char *name;
dev_t devt;
struct ida minor_ida;
};
/*
* Since user file names are global in DSA devices, define their ida's as
* global to avoid conflict file names.
*/
static DEFINE_IDA(file_ida);
static DEFINE_MUTEX(ida_lock);
/*
* ictx is an array based off of accelerator types. enum idxd_type
* is used as index
*/
static struct idxd_cdev_context ictx[IDXD_TYPE_MAX] = {
{ .name = "dsa" },
{ .name = "iax" }
};
struct idxd_user_context {
struct idxd_wq *wq;
struct task_struct *task;
unsigned int pasid;
struct mm_struct *mm;
unsigned int flags;
struct iommu_sva *sva;
struct idxd_dev idxd_dev;
u64 counters[COUNTER_MAX];
int id;
pid_t pid;
};
static void idxd_cdev_evl_drain_pasid(struct idxd_wq *wq, u32 pasid);
static void idxd_xa_pasid_remove(struct idxd_user_context *ctx);
static inline struct idxd_user_context *dev_to_uctx(struct device *dev)
{
struct idxd_dev *idxd_dev = confdev_to_idxd_dev(dev);
return container_of(idxd_dev, struct idxd_user_context, idxd_dev);
}
static ssize_t cr_faults_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct idxd_user_context *ctx = dev_to_uctx(dev);
return sysfs_emit(buf, "%llu\n", ctx->counters[COUNTER_FAULTS]);
}
static DEVICE_ATTR_RO(cr_faults);
static ssize_t cr_fault_failures_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct idxd_user_context *ctx = dev_to_uctx(dev);
return sysfs_emit(buf, "%llu\n", ctx->counters[COUNTER_FAULT_FAILS]);
}
static DEVICE_ATTR_RO(cr_fault_failures);
static ssize_t pid_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct idxd_user_context *ctx = dev_to_uctx(dev);
return sysfs_emit(buf, "%u\n", ctx->pid);
}
static DEVICE_ATTR_RO(pid);
static struct attribute *cdev_file_attributes[] = {
&dev_attr_cr_faults.attr,
&dev_attr_cr_fault_failures.attr,
&dev_attr_pid.attr,
NULL
};
static umode_t cdev_file_attr_visible(struct kobject *kobj, struct attribute *a, int n)
{
struct device *dev = container_of(kobj, typeof(*dev), kobj);
struct idxd_user_context *ctx = dev_to_uctx(dev);
struct idxd_wq *wq = ctx->wq;
if (!wq_pasid_enabled(wq))
return 0;
return a->mode;
}
static const struct attribute_group cdev_file_attribute_group = {
.attrs = cdev_file_attributes,
.is_visible = cdev_file_attr_visible,
};
static const struct attribute_group *cdev_file_attribute_groups[] = {
&cdev_file_attribute_group,
NULL
};
static void idxd_file_dev_release(struct device *dev)
{
struct idxd_user_context *ctx = dev_to_uctx(dev);
struct idxd_wq *wq = ctx->wq;
struct idxd_device *idxd = wq->idxd;
int rc;
mutex_lock(&ida_lock);
ida_free(&file_ida, ctx->id);
mutex_unlock(&ida_lock);
/* Wait for in-flight operations to complete. */
if (wq_shared(wq)) {
idxd_device_drain_pasid(idxd, ctx->pasid);
} else {
if (device_user_pasid_enabled(idxd)) {
/* The wq disable in the disable pasid function will drain the wq */
rc = idxd_wq_disable_pasid(wq);
if (rc < 0)
dev_err(dev, "wq disable pasid failed.\n");
} else {
idxd_wq_drain(wq);
}
}
if (ctx->sva) {
idxd_cdev_evl_drain_pasid(wq, ctx->pasid);
iommu_sva_unbind_device(ctx->sva);
idxd_xa_pasid_remove(ctx);
}
kfree(ctx);
mutex_lock(&wq->wq_lock);
idxd_wq_put(wq);
mutex_unlock(&wq->wq_lock);
}
static const struct device_type idxd_cdev_file_type = {
.name = "idxd_file",
.release = idxd_file_dev_release,
.groups = cdev_file_attribute_groups,
};
static void idxd_cdev_dev_release(struct device *dev)
{
struct idxd_cdev *idxd_cdev = dev_to_cdev(dev);
struct idxd_cdev_context *cdev_ctx;
struct idxd_wq *wq = idxd_cdev->wq;
cdev_ctx = &ictx[wq->idxd->data->type];
ida_free(&cdev_ctx->minor_ida, idxd_cdev->minor);
kfree(idxd_cdev);
}
static const struct device_type idxd_cdev_device_type = {
.name = "idxd_cdev",
.release = idxd_cdev_dev_release,
};
static inline struct idxd_cdev *inode_idxd_cdev(struct inode *inode)
{
struct cdev *cdev = inode->i_cdev;
return container_of(cdev, struct idxd_cdev, cdev);
}
static inline struct idxd_wq *inode_wq(struct inode *inode)
{
struct idxd_cdev *idxd_cdev = inode_idxd_cdev(inode);
return idxd_cdev->wq;
}
static void idxd_xa_pasid_remove(struct idxd_user_context *ctx)
{
struct idxd_wq *wq = ctx->wq;
void *ptr;
mutex_lock(&wq->uc_lock);
ptr = xa_cmpxchg(&wq->upasid_xa, ctx->pasid, ctx, NULL, GFP_KERNEL);
if (ptr != (void *)ctx)
dev_warn(&wq->idxd->pdev->dev, "xarray cmpxchg failed for pasid %u\n",
ctx->pasid);
mutex_unlock(&wq->uc_lock);
}
void idxd_user_counter_increment(struct idxd_wq *wq, u32 pasid, int index)
{
struct idxd_user_context *ctx;
if (index >= COUNTER_MAX)
return;
mutex_lock(&wq->uc_lock);
ctx = xa_load(&wq->upasid_xa, pasid);
if (!ctx) {
mutex_unlock(&wq->uc_lock);
return;
}
ctx->counters[index]++;
mutex_unlock(&wq->uc_lock);
}
static int idxd_cdev_open(struct inode *inode, struct file *filp)
{
struct idxd_user_context *ctx;
struct idxd_device *idxd;
struct idxd_wq *wq;
struct device *dev, *fdev;
int rc = 0;
struct iommu_sva *sva;
unsigned int pasid;
struct idxd_cdev *idxd_cdev;
wq = inode_wq(inode);
idxd = wq->idxd;
dev = &idxd->pdev->dev;
dev_dbg(dev, "%s called: %d\n", __func__, idxd_wq_refcount(wq));
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
mutex_lock(&wq->wq_lock);
if (idxd_wq_refcount(wq) > 0 && wq_dedicated(wq)) {
rc = -EBUSY;
goto failed;
}
ctx->wq = wq;
filp->private_data = ctx;
ctx->pid = current->pid;
if (device_user_pasid_enabled(idxd)) {
sva = iommu_sva_bind_device(dev, current->mm);
if (IS_ERR(sva)) {
rc = PTR_ERR(sva);
dev_err(dev, "pasid allocation failed: %d\n", rc);
goto failed;
}
pasid = iommu_sva_get_pasid(sva);
if (pasid == IOMMU_PASID_INVALID) {
rc = -EINVAL;
goto failed_get_pasid;
}
ctx->sva = sva;
ctx->pasid = pasid;
ctx->mm = current->mm;
mutex_lock(&wq->uc_lock);
rc = xa_insert(&wq->upasid_xa, pasid, ctx, GFP_KERNEL);
mutex_unlock(&wq->uc_lock);
if (rc < 0)
dev_warn(dev, "PASID entry already exist in xarray.\n");
if (wq_dedicated(wq)) {
rc = idxd_wq_set_pasid(wq, pasid);
if (rc < 0) {
dev_err(dev, "wq set pasid failed: %d\n", rc);
goto failed_set_pasid;
}
}
}
idxd_cdev = wq->idxd_cdev;
mutex_lock(&ida_lock);
ctx->id = ida_alloc(&file_ida, GFP_KERNEL);
mutex_unlock(&ida_lock);
if (ctx->id < 0) {
dev_warn(dev, "ida alloc failure\n");
goto failed_ida;
}
ctx->idxd_dev.type = IDXD_DEV_CDEV_FILE;
fdev = user_ctx_dev(ctx);
device_initialize(fdev);
fdev->parent = cdev_dev(idxd_cdev);
fdev->bus = &dsa_bus_type;
fdev->type = &idxd_cdev_file_type;
rc = dev_set_name(fdev, "file%d", ctx->id);
if (rc < 0) {
dev_warn(dev, "set name failure\n");
goto failed_dev_name;
}
rc = device_add(fdev);
if (rc < 0) {
dev_warn(dev, "file device add failure\n");
goto failed_dev_add;
}
idxd_wq_get(wq);
mutex_unlock(&wq->wq_lock);
return 0;
failed_dev_add:
failed_dev_name:
put_device(fdev);
failed_ida:
failed_set_pasid:
if (device_user_pasid_enabled(idxd))
idxd_xa_pasid_remove(ctx);
failed_get_pasid:
if (device_user_pasid_enabled(idxd))
iommu_sva_unbind_device(sva);
failed:
mutex_unlock(&wq->wq_lock);
kfree(ctx);
return rc;
}
static void idxd_cdev_evl_drain_pasid(struct idxd_wq *wq, u32 pasid)
{
struct idxd_device *idxd = wq->idxd;
struct idxd_evl *evl = idxd->evl;
union evl_status_reg status;
u16 h, t, size;
int ent_size = evl_ent_size(idxd);
struct __evl_entry *entry_head;
if (!evl)
return;
mutex_lock(&evl->lock);
status.bits = ioread64(idxd->reg_base + IDXD_EVLSTATUS_OFFSET);
t = status.tail;
h = status.head;
size = evl->size;
while (h != t) {
entry_head = (struct __evl_entry *)(evl->log + (h * ent_size));
if (entry_head->pasid == pasid && entry_head->wq_idx == wq->id)
set_bit(h, evl->bmap);
h = (h + 1) % size;
}
drain_workqueue(wq->wq);
mutex_unlock(&evl->lock);
}
static int idxd_cdev_release(struct inode *node, struct file *filep)
{
struct idxd_user_context *ctx = filep->private_data;
struct idxd_wq *wq = ctx->wq;
struct idxd_device *idxd = wq->idxd;
struct device *dev = &idxd->pdev->dev;
dev_dbg(dev, "%s called\n", __func__);
filep->private_data = NULL;
device_unregister(user_ctx_dev(ctx));
return 0;
}
static int check_vma(struct idxd_wq *wq, struct vm_area_struct *vma,
const char *func)
{
struct device *dev = &wq->idxd->pdev->dev;
if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
dev_info_ratelimited(dev,
"%s: %s: mapping too large: %lu\n",
current->comm, func,
vma->vm_end - vma->vm_start);
return -EINVAL;
}
return 0;
}
static int idxd_cdev_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct idxd_user_context *ctx = filp->private_data;
struct idxd_wq *wq = ctx->wq;
struct idxd_device *idxd = wq->idxd;
struct pci_dev *pdev = idxd->pdev;
phys_addr_t base = pci_resource_start(pdev, IDXD_WQ_BAR);
unsigned long pfn;
int rc;
dev_dbg(&pdev->dev, "%s called\n", __func__);
rc = check_vma(wq, vma, __func__);
if (rc < 0)
return rc;
vm_flags_set(vma, VM_DONTCOPY);
pfn = (base + idxd_get_wq_portal_full_offset(wq->id,
IDXD_PORTAL_LIMITED)) >> PAGE_SHIFT;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_private_data = ctx;
return io_remap_pfn_range(vma, vma->vm_start, pfn, PAGE_SIZE,
vma->vm_page_prot);
}
static __poll_t idxd_cdev_poll(struct file *filp,
struct poll_table_struct *wait)
{
struct idxd_user_context *ctx = filp->private_data;
struct idxd_wq *wq = ctx->wq;
struct idxd_device *idxd = wq->idxd;
__poll_t out = 0;
poll_wait(filp, &wq->err_queue, wait);
spin_lock(&idxd->dev_lock);
if (idxd->sw_err.valid)
out = EPOLLIN | EPOLLRDNORM;
spin_unlock(&idxd->dev_lock);
return out;
}
static const struct file_operations idxd_cdev_fops = {
.owner = THIS_MODULE,
.open = idxd_cdev_open,
.release = idxd_cdev_release,
.mmap = idxd_cdev_mmap,
.poll = idxd_cdev_poll,
};
int idxd_cdev_get_major(struct idxd_device *idxd)
{
return MAJOR(ictx[idxd->data->type].devt);
}
int idxd_wq_add_cdev(struct idxd_wq *wq)
{
struct idxd_device *idxd = wq->idxd;
struct idxd_cdev *idxd_cdev;
struct cdev *cdev;
struct device *dev;
struct idxd_cdev_context *cdev_ctx;
int rc, minor;
idxd_cdev = kzalloc(sizeof(*idxd_cdev), GFP_KERNEL);
if (!idxd_cdev)
return -ENOMEM;
idxd_cdev->idxd_dev.type = IDXD_DEV_CDEV;
idxd_cdev->wq = wq;
cdev = &idxd_cdev->cdev;
dev = cdev_dev(idxd_cdev);
cdev_ctx = &ictx[wq->idxd->data->type];
minor = ida_alloc_max(&cdev_ctx->minor_ida, MINORMASK, GFP_KERNEL);
if (minor < 0) {
kfree(idxd_cdev);
return minor;
}
idxd_cdev->minor = minor;
device_initialize(dev);
dev->parent = wq_confdev(wq);
dev->bus = &dsa_bus_type;
dev->type = &idxd_cdev_device_type;
dev->devt = MKDEV(MAJOR(cdev_ctx->devt), minor);
rc = dev_set_name(dev, "%s/wq%u.%u", idxd->data->name_prefix, idxd->id, wq->id);
if (rc < 0)
goto err;
wq->idxd_cdev = idxd_cdev;
cdev_init(cdev, &idxd_cdev_fops);
rc = cdev_device_add(cdev, dev);
if (rc) {
dev_dbg(&wq->idxd->pdev->dev, "cdev_add failed: %d\n", rc);
goto err;
}
return 0;
err:
put_device(dev);
wq->idxd_cdev = NULL;
return rc;
}
void idxd_wq_del_cdev(struct idxd_wq *wq)
{
struct idxd_cdev *idxd_cdev;
idxd_cdev = wq->idxd_cdev;
ida_destroy(&file_ida);
wq->idxd_cdev = NULL;
cdev_device_del(&idxd_cdev->cdev, cdev_dev(idxd_cdev));
put_device(cdev_dev(idxd_cdev));
}
static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
{
struct device *dev = &idxd_dev->conf_dev;
struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
struct idxd_device *idxd = wq->idxd;
int rc;
if (idxd->state != IDXD_DEV_ENABLED)
return -ENXIO;
/*
* User type WQ is enabled only when SVA is enabled for two reasons:
* - If no IOMMU or IOMMU Passthrough without SVA, userspace
* can directly access physical address through the WQ.
* - The IDXD cdev driver does not provide any ways to pin
* user pages and translate the address from user VA to IOVA or
* PA without IOMMU SVA. Therefore the application has no way
* to instruct the device to perform DMA function. This makes
* the cdev not usable for normal application usage.
*/
if (!device_user_pasid_enabled(idxd)) {
idxd->cmd_status = IDXD_SCMD_WQ_USER_NO_IOMMU;
dev_dbg(&idxd->pdev->dev,
"User type WQ cannot be enabled without SVA.\n");
return -EOPNOTSUPP;
}
mutex_lock(&wq->wq_lock);
if (!idxd_wq_driver_name_match(wq, dev)) {
idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
rc = -ENODEV;
goto wq_err;
}
wq->wq = create_workqueue(dev_name(wq_confdev(wq)));
if (!wq->wq) {
rc = -ENOMEM;
goto wq_err;
}
wq->type = IDXD_WQT_USER;
rc = idxd_drv_enable_wq(wq);
if (rc < 0)
goto err;
rc = idxd_wq_add_cdev(wq);
if (rc < 0) {
idxd->cmd_status = IDXD_SCMD_CDEV_ERR;
goto err_cdev;
}
idxd->cmd_status = 0;
mutex_unlock(&wq->wq_lock);
return 0;
err_cdev:
idxd_drv_disable_wq(wq);
err:
destroy_workqueue(wq->wq);
wq->type = IDXD_WQT_NONE;
wq_err:
mutex_unlock(&wq->wq_lock);
return rc;
}
static void idxd_user_drv_remove(struct idxd_dev *idxd_dev)
{
struct idxd_wq *wq = idxd_dev_to_wq(idxd_dev);
mutex_lock(&wq->wq_lock);
idxd_wq_del_cdev(wq);
idxd_drv_disable_wq(wq);
wq->type = IDXD_WQT_NONE;
destroy_workqueue(wq->wq);
wq->wq = NULL;
mutex_unlock(&wq->wq_lock);
}
static enum idxd_dev_type dev_types[] = {
IDXD_DEV_WQ,
IDXD_DEV_NONE,
};
struct idxd_device_driver idxd_user_drv = {
.probe = idxd_user_drv_probe,
.remove = idxd_user_drv_remove,
.name = "user",
.type = dev_types,
};
EXPORT_SYMBOL_GPL(idxd_user_drv);
int idxd_cdev_register(void)
{
int rc, i;
for (i = 0; i < IDXD_TYPE_MAX; i++) {
ida_init(&ictx[i].minor_ida);
rc = alloc_chrdev_region(&ictx[i].devt, 0, MINORMASK,
ictx[i].name);
if (rc)
goto err_free_chrdev_region;
}
return 0;
err_free_chrdev_region:
for (i--; i >= 0; i--)
unregister_chrdev_region(ictx[i].devt, MINORMASK);
return rc;
}
void idxd_cdev_remove(void)
{
int i;
for (i = 0; i < IDXD_TYPE_MAX; i++) {
unregister_chrdev_region(ictx[i].devt, MINORMASK);
ida_destroy(&ictx[i].minor_ida);
}
}
/**
* idxd_copy_cr - copy completion record to user address space found by wq and
* PASID
* @wq: work queue
* @pasid: PASID
* @addr: user fault address to write
* @cr: completion record
* @len: number of bytes to copy
*
* This is called by a work that handles completion record fault.
*
* Return: number of bytes copied.
*/
int idxd_copy_cr(struct idxd_wq *wq, ioasid_t pasid, unsigned long addr,
void *cr, int len)
{
struct device *dev = &wq->idxd->pdev->dev;
int left = len, status_size = 1;
struct idxd_user_context *ctx;
struct mm_struct *mm;
mutex_lock(&wq->uc_lock);
ctx = xa_load(&wq->upasid_xa, pasid);
if (!ctx) {
dev_warn(dev, "No user context\n");
goto out;
}
mm = ctx->mm;
/*
* The completion record fault handling work is running in kernel
* thread context. It temporarily switches to the mm to copy cr
* to addr in the mm.
*/
kthread_use_mm(mm);
left = copy_to_user((void __user *)addr + status_size, cr + status_size,
len - status_size);
/*
* Copy status only after the rest of completion record is copied
* successfully so that the user gets the complete completion record
* when a non-zero status is polled.
*/
if (!left) {
u8 status;
/*
* Ensure that the completion record's status field is written
* after the rest of the completion record has been written.
* This ensures that the user receives the correct completion
* record information once polling for a non-zero status.
*/
wmb();
status = *(u8 *)cr;
if (put_user(status, (u8 __user *)addr))
left += status_size;
} else {
left += status_size;
}
kthread_unuse_mm(mm);
out:
mutex_unlock(&wq->uc_lock);
return len - left;
}