- 根目录:
- drivers
- misc
- cxl
- file.c
/*
* Copyright 2014 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/bitmap.h>
#include <linux/sched.h>
#include <linux/poll.h>
#include <linux/pid.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <asm/cputable.h>
#include <asm/current.h>
#include <asm/copro.h>
#include "cxl.h"
#include "trace.h"
#define CXL_NUM_MINORS 256 /* Total to reserve */
#define CXL_DEV_MINORS 13 /* 1 control + 4 AFUs * 3 (dedicated/master/shared) */
#define CXL_CARD_MINOR(adapter) (adapter->adapter_num * CXL_DEV_MINORS)
#define CXL_AFU_MINOR_D(afu) (CXL_CARD_MINOR(afu->adapter) + 1 + (3 * afu->slice))
#define CXL_AFU_MINOR_M(afu) (CXL_AFU_MINOR_D(afu) + 1)
#define CXL_AFU_MINOR_S(afu) (CXL_AFU_MINOR_D(afu) + 2)
#define CXL_AFU_MKDEV_D(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_D(afu))
#define CXL_AFU_MKDEV_M(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_M(afu))
#define CXL_AFU_MKDEV_S(afu) MKDEV(MAJOR(cxl_dev), CXL_AFU_MINOR_S(afu))
#define CXL_DEVT_ADAPTER(dev) (MINOR(dev) / CXL_DEV_MINORS)
#define CXL_DEVT_AFU(dev) ((MINOR(dev) % CXL_DEV_MINORS - 1) / 3)
#define CXL_DEVT_IS_CARD(dev) (MINOR(dev) % CXL_DEV_MINORS == 0)
static dev_t cxl_dev;
static struct class *cxl_class;
static int __afu_open(struct inode *inode, struct file *file, bool master)
{
struct cxl *adapter;
struct cxl_afu *afu;
struct cxl_context *ctx;
int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
int slice = CXL_DEVT_AFU(inode->i_rdev);
int rc = -ENODEV;
pr_devel("afu_open afu%i.%i\n", slice, adapter_num);
if (!(adapter = get_cxl_adapter(adapter_num)))
return -ENODEV;
if (slice > adapter->slices)
goto err_put_adapter;
spin_lock(&adapter->afu_list_lock);
if (!(afu = adapter->afu[slice])) {
spin_unlock(&adapter->afu_list_lock);
goto err_put_adapter;
}
get_device(&afu->dev);
spin_unlock(&adapter->afu_list_lock);
if (!afu->current_mode)
goto err_put_afu;
if (!cxl_adapter_link_ok(adapter)) {
rc = -EIO;
goto err_put_afu;
}
if (!(ctx = cxl_context_alloc())) {
rc = -ENOMEM;
goto err_put_afu;
}
if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping)))
goto err_put_afu;
pr_devel("afu_open pe: %i\n", ctx->pe);
file->private_data = ctx;
cxl_ctx_get();
/* Our ref on the AFU will now hold the adapter */
put_device(&adapter->dev);
return 0;
err_put_afu:
put_device(&afu->dev);
err_put_adapter:
put_device(&adapter->dev);
return rc;
}
int afu_open(struct inode *inode, struct file *file)
{
return __afu_open(inode, file, false);
}
static int afu_master_open(struct inode *inode, struct file *file)
{
return __afu_open(inode, file, true);
}
int afu_release(struct inode *inode, struct file *file)
{
struct cxl_context *ctx = file->private_data;
pr_devel("%s: closing cxl file descriptor. pe: %i\n",
__func__, ctx->pe);
cxl_context_detach(ctx);
/*
* Delete the context's mapping pointer, unless it's created by the
* kernel API, in which case leave it so it can be freed by reclaim_ctx()
*/
if (!ctx->kernelapi) {
mutex_lock(&ctx->mapping_lock);
ctx->mapping = NULL;
mutex_unlock(&ctx->mapping_lock);
}
put_device(&ctx->afu->dev);
/*
* At this this point all bottom halfs have finished and we should be
* getting no more IRQs from the hardware for this context. Once it's
* removed from the IDR (and RCU synchronised) it's safe to free the
* sstp and context.
*/
cxl_context_free(ctx);
return 0;
}
static long afu_ioctl_start_work(struct cxl_context *ctx,
struct cxl_ioctl_start_work __user *uwork)
{
struct cxl_ioctl_start_work work;
u64 amr = 0;
int rc;
pr_devel("%s: pe: %i\n", __func__, ctx->pe);
/* Do this outside the status_mutex to avoid a circular dependency with
* the locking in cxl_mmap_fault() */
if (copy_from_user(&work, uwork,
sizeof(struct cxl_ioctl_start_work))) {
rc = -EFAULT;
goto out;
}
mutex_lock(&ctx->status_mutex);
if (ctx->status != OPENED) {
rc = -EIO;
goto out;
}
/*
* if any of the reserved fields are set or any of the unused
* flags are set it's invalid
*/
if (work.reserved1 || work.reserved2 || work.reserved3 ||
work.reserved4 || work.reserved5 || work.reserved6 ||
(work.flags & ~CXL_START_WORK_ALL)) {
rc = -EINVAL;
goto out;
}
if (!(work.flags & CXL_START_WORK_NUM_IRQS))
work.num_interrupts = ctx->afu->pp_irqs;
else if ((work.num_interrupts < ctx->afu->pp_irqs) ||
(work.num_interrupts > ctx->afu->irqs_max)) {
rc = -EINVAL;
goto out;
}
if ((rc = afu_register_irqs(ctx, work.num_interrupts)))
goto out;
if (work.flags & CXL_START_WORK_AMR)
amr = work.amr & mfspr(SPRN_UAMOR);
ctx->mmio_err_ff = !!(work.flags & CXL_START_WORK_ERR_FF);
/*
* We grab the PID here and not in the file open to allow for the case
* where a process (master, some daemon, etc) has opened the chardev on
* behalf of another process, so the AFU's mm gets bound to the process
* that performs this ioctl and not the process that opened the file.
*/
ctx->pid = get_pid(get_task_pid(current, PIDTYPE_PID));
trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
if ((rc = cxl_attach_process(ctx, false, work.work_element_descriptor,
amr))) {
afu_release_irqs(ctx, ctx);
goto out;
}
ctx->status = STARTED;
rc = 0;
out:
mutex_unlock(&ctx->status_mutex);
return rc;
}
static long afu_ioctl_process_element(struct cxl_context *ctx,
int __user *upe)
{
pr_devel("%s: pe: %i\n", __func__, ctx->pe);
if (copy_to_user(upe, &ctx->pe, sizeof(__u32)))
return -EFAULT;
return 0;
}
static long afu_ioctl_get_afu_id(struct cxl_context *ctx,
struct cxl_afu_id __user *upafuid)
{
struct cxl_afu_id afuid = { 0 };
afuid.card_id = ctx->afu->adapter->adapter_num;
afuid.afu_offset = ctx->afu->slice;
afuid.afu_mode = ctx->afu->current_mode;
/* set the flag bit in case the afu is a slave */
if (ctx->afu->current_mode == CXL_MODE_DIRECTED && !ctx->master)
afuid.flags |= CXL_AFUID_FLAG_SLAVE;
if (copy_to_user(upafuid, &afuid, sizeof(afuid)))
return -EFAULT;
return 0;
}
long afu_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct cxl_context *ctx = file->private_data;
if (ctx->status == CLOSED)
return -EIO;
if (!cxl_adapter_link_ok(ctx->afu->adapter))
return -EIO;
pr_devel("afu_ioctl\n");
switch (cmd) {
case CXL_IOCTL_START_WORK:
return afu_ioctl_start_work(ctx, (struct cxl_ioctl_start_work __user *)arg);
case CXL_IOCTL_GET_PROCESS_ELEMENT:
return afu_ioctl_process_element(ctx, (__u32 __user *)arg);
case CXL_IOCTL_GET_AFU_ID:
return afu_ioctl_get_afu_id(ctx, (struct cxl_afu_id __user *)
arg);
}
return -EINVAL;
}
static long afu_compat_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
return afu_ioctl(file, cmd, arg);
}
int afu_mmap(struct file *file, struct vm_area_struct *vm)
{
struct cxl_context *ctx = file->private_data;
/* AFU must be started before we can MMIO */
if (ctx->status != STARTED)
return -EIO;
if (!cxl_adapter_link_ok(ctx->afu->adapter))
return -EIO;
return cxl_context_iomap(ctx, vm);
}
unsigned int afu_poll(struct file *file, struct poll_table_struct *poll)
{
struct cxl_context *ctx = file->private_data;
int mask = 0;
unsigned long flags;
poll_wait(file, &ctx->wq, poll);
pr_devel("afu_poll wait done pe: %i\n", ctx->pe);
spin_lock_irqsave(&ctx->lock, flags);
if (ctx->pending_irq || ctx->pending_fault ||
ctx->pending_afu_err)
mask |= POLLIN | POLLRDNORM;
else if (ctx->status == CLOSED)
/* Only error on closed when there are no futher events pending
*/
mask |= POLLERR;
spin_unlock_irqrestore(&ctx->lock, flags);
pr_devel("afu_poll pe: %i returning %#x\n", ctx->pe, mask);
return mask;
}
static inline int ctx_event_pending(struct cxl_context *ctx)
{
return (ctx->pending_irq || ctx->pending_fault ||
ctx->pending_afu_err || (ctx->status == CLOSED));
}
ssize_t afu_read(struct file *file, char __user *buf, size_t count,
loff_t *off)
{
struct cxl_context *ctx = file->private_data;
struct cxl_event event;
unsigned long flags;
int rc;
DEFINE_WAIT(wait);
if (!cxl_adapter_link_ok(ctx->afu->adapter))
return -EIO;
if (count < CXL_READ_MIN_SIZE)
return -EINVAL;
spin_lock_irqsave(&ctx->lock, flags);
for (;;) {
prepare_to_wait(&ctx->wq, &wait, TASK_INTERRUPTIBLE);
if (ctx_event_pending(ctx))
break;
if (!cxl_adapter_link_ok(ctx->afu->adapter)) {
rc = -EIO;
goto out;
}
if (file->f_flags & O_NONBLOCK) {
rc = -EAGAIN;
goto out;
}
if (signal_pending(current)) {
rc = -ERESTARTSYS;
goto out;
}
spin_unlock_irqrestore(&ctx->lock, flags);
pr_devel("afu_read going to sleep...\n");
schedule();
pr_devel("afu_read woken up\n");
spin_lock_irqsave(&ctx->lock, flags);
}
finish_wait(&ctx->wq, &wait);
memset(&event, 0, sizeof(event));
event.header.process_element = ctx->pe;
event.header.size = sizeof(struct cxl_event_header);
if (ctx->pending_irq) {
pr_devel("afu_read delivering AFU interrupt\n");
event.header.size += sizeof(struct cxl_event_afu_interrupt);
event.header.type = CXL_EVENT_AFU_INTERRUPT;
event.irq.irq = find_first_bit(ctx->irq_bitmap, ctx->irq_count) + 1;
clear_bit(event.irq.irq - 1, ctx->irq_bitmap);
if (bitmap_empty(ctx->irq_bitmap, ctx->irq_count))
ctx->pending_irq = false;
} else if (ctx->pending_fault) {
pr_devel("afu_read delivering data storage fault\n");
event.header.size += sizeof(struct cxl_event_data_storage);
event.header.type = CXL_EVENT_DATA_STORAGE;
event.fault.addr = ctx->fault_addr;
event.fault.dsisr = ctx->fault_dsisr;
ctx->pending_fault = false;
} else if (ctx->pending_afu_err) {
pr_devel("afu_read delivering afu error\n");
event.header.size += sizeof(struct cxl_event_afu_error);
event.header.type = CXL_EVENT_AFU_ERROR;
event.afu_error.error = ctx->afu_err;
ctx->pending_afu_err = false;
} else if (ctx->status == CLOSED) {
pr_devel("afu_read fatal error\n");
spin_unlock_irqrestore(&ctx->lock, flags);
return -EIO;
} else
WARN(1, "afu_read must be buggy\n");
spin_unlock_irqrestore(&ctx->lock, flags);
if (copy_to_user(buf, &event, event.header.size))
return -EFAULT;
return event.header.size;
out:
finish_wait(&ctx->wq, &wait);
spin_unlock_irqrestore(&ctx->lock, flags);
return rc;
}
/*
* Note: if this is updated, we need to update api.c to patch the new ones in
* too
*/
const struct file_operations afu_fops = {
.owner = THIS_MODULE,
.open = afu_open,
.poll = afu_poll,
.read = afu_read,
.release = afu_release,
.unlocked_ioctl = afu_ioctl,
.compat_ioctl = afu_compat_ioctl,
.mmap = afu_mmap,
};
static const struct file_operations afu_master_fops = {
.owner = THIS_MODULE,
.open = afu_master_open,
.poll = afu_poll,
.read = afu_read,
.release = afu_release,
.unlocked_ioctl = afu_ioctl,
.compat_ioctl = afu_compat_ioctl,
.mmap = afu_mmap,
};
static char *cxl_devnode(struct device *dev, umode_t *mode)
{
if (CXL_DEVT_IS_CARD(dev->devt)) {
/*
* These minor numbers will eventually be used to program the
* PSL and AFUs once we have dynamic reprogramming support
*/
return NULL;
}
return kasprintf(GFP_KERNEL, "cxl/%s", dev_name(dev));
}
extern struct class *cxl_class;
static int cxl_add_chardev(struct cxl_afu *afu, dev_t devt, struct cdev *cdev,
struct device **chardev, char *postfix, char *desc,
const struct file_operations *fops)
{
struct device *dev;
int rc;
cdev_init(cdev, fops);
if ((rc = cdev_add(cdev, devt, 1))) {
dev_err(&afu->dev, "Unable to add %s chardev: %i\n", desc, rc);
return rc;
}
dev = device_create(cxl_class, &afu->dev, devt, afu,
"afu%i.%i%s", afu->adapter->adapter_num, afu->slice, postfix);
if (IS_ERR(dev)) {
dev_err(&afu->dev, "Unable to create %s chardev in sysfs: %i\n", desc, rc);
rc = PTR_ERR(dev);
goto err;
}
*chardev = dev;
return 0;
err:
cdev_del(cdev);
return rc;
}
int cxl_chardev_d_afu_add(struct cxl_afu *afu)
{
return cxl_add_chardev(afu, CXL_AFU_MKDEV_D(afu), &afu->afu_cdev_d,
&afu->chardev_d, "d", "dedicated",
&afu_master_fops); /* Uses master fops */
}
int cxl_chardev_m_afu_add(struct cxl_afu *afu)
{
return cxl_add_chardev(afu, CXL_AFU_MKDEV_M(afu), &afu->afu_cdev_m,
&afu->chardev_m, "m", "master",
&afu_master_fops);
}
int cxl_chardev_s_afu_add(struct cxl_afu *afu)
{
return cxl_add_chardev(afu, CXL_AFU_MKDEV_S(afu), &afu->afu_cdev_s,
&afu->chardev_s, "s", "shared",
&afu_fops);
}
void cxl_chardev_afu_remove(struct cxl_afu *afu)
{
if (afu->chardev_d) {
cdev_del(&afu->afu_cdev_d);
device_unregister(afu->chardev_d);
afu->chardev_d = NULL;
}
if (afu->chardev_m) {
cdev_del(&afu->afu_cdev_m);
device_unregister(afu->chardev_m);
afu->chardev_m = NULL;
}
if (afu->chardev_s) {
cdev_del(&afu->afu_cdev_s);
device_unregister(afu->chardev_s);
afu->chardev_s = NULL;
}
}
int cxl_register_afu(struct cxl_afu *afu)
{
afu->dev.class = cxl_class;
return device_register(&afu->dev);
}
int cxl_register_adapter(struct cxl *adapter)
{
adapter->dev.class = cxl_class;
/*
* Future: When we support dynamically reprogramming the PSL & AFU we
* will expose the interface to do that via a chardev:
* adapter->dev.devt = CXL_CARD_MKDEV(adapter);
*/
return device_register(&adapter->dev);
}
int __init cxl_file_init(void)
{
int rc;
/*
* If these change we really need to update API. Either change some
* flags or update API version number CXL_API_VERSION.
*/
BUILD_BUG_ON(CXL_API_VERSION != 2);
BUILD_BUG_ON(sizeof(struct cxl_ioctl_start_work) != 64);
BUILD_BUG_ON(sizeof(struct cxl_event_header) != 8);
BUILD_BUG_ON(sizeof(struct cxl_event_afu_interrupt) != 8);
BUILD_BUG_ON(sizeof(struct cxl_event_data_storage) != 32);
BUILD_BUG_ON(sizeof(struct cxl_event_afu_error) != 16);
if ((rc = alloc_chrdev_region(&cxl_dev, 0, CXL_NUM_MINORS, "cxl"))) {
pr_err("Unable to allocate CXL major number: %i\n", rc);
return rc;
}
pr_devel("CXL device allocated, MAJOR %i\n", MAJOR(cxl_dev));
cxl_class = class_create(THIS_MODULE, "cxl");
if (IS_ERR(cxl_class)) {
pr_err("Unable to create CXL class\n");
rc = PTR_ERR(cxl_class);
goto err;
}
cxl_class->devnode = cxl_devnode;
return 0;
err:
unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
return rc;
}
void cxl_file_exit(void)
{
unregister_chrdev_region(cxl_dev, CXL_NUM_MINORS);
class_destroy(cxl_class);
}