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|
/*
* CXL Flash Device Driver
*
* Written by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
* Uma Krishnan <ukrishn@linux.vnet.ibm.com>, IBM Corporation
*
* Copyright (C) 2018 IBM Corporation
*
* 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/file.h>
#include <linux/idr.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <misc/ocxl.h>
#include "backend.h"
#include "ocxl_hw.h"
/*
* Pseudo-filesystem to allocate inodes.
*/
#define OCXLFLASH_FS_MAGIC 0x1697698f
static int ocxlflash_fs_cnt;
static struct vfsmount *ocxlflash_vfs_mount;
static const struct dentry_operations ocxlflash_fs_dops = {
.d_dname = simple_dname,
};
/*
* ocxlflash_fs_mount() - mount the pseudo-filesystem
* @fs_type: File system type.
* @flags: Flags for the filesystem.
* @dev_name: Device name associated with the filesystem.
* @data: Data pointer.
*
* Return: pointer to the directory entry structure
*/
static struct dentry *ocxlflash_fs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data)
{
return mount_pseudo(fs_type, "ocxlflash:", NULL, &ocxlflash_fs_dops,
OCXLFLASH_FS_MAGIC);
}
static struct file_system_type ocxlflash_fs_type = {
.name = "ocxlflash",
.owner = THIS_MODULE,
.mount = ocxlflash_fs_mount,
.kill_sb = kill_anon_super,
};
/*
* ocxlflash_release_mapping() - release the memory mapping
* @ctx: Context whose mapping is to be released.
*/
static void ocxlflash_release_mapping(struct ocxlflash_context *ctx)
{
if (ctx->mapping)
simple_release_fs(&ocxlflash_vfs_mount, &ocxlflash_fs_cnt);
ctx->mapping = NULL;
}
/*
* ocxlflash_getfile() - allocate pseudo filesystem, inode, and the file
* @dev: Generic device of the host.
* @name: Name of the pseudo filesystem.
* @fops: File operations.
* @priv: Private data.
* @flags: Flags for the file.
*
* Return: pointer to the file on success, ERR_PTR on failure
*/
static struct file *ocxlflash_getfile(struct device *dev, const char *name,
const struct file_operations *fops,
void *priv, int flags)
{
struct qstr this;
struct path path;
struct file *file;
struct inode *inode = NULL;
int rc;
if (fops->owner && !try_module_get(fops->owner)) {
dev_err(dev, "%s: Owner does not exist\n", __func__);
rc = -ENOENT;
goto err1;
}
rc = simple_pin_fs(&ocxlflash_fs_type, &ocxlflash_vfs_mount,
&ocxlflash_fs_cnt);
if (unlikely(rc < 0)) {
dev_err(dev, "%s: Cannot mount ocxlflash pseudofs rc=%d\n",
__func__, rc);
goto err2;
}
inode = alloc_anon_inode(ocxlflash_vfs_mount->mnt_sb);
if (IS_ERR(inode)) {
rc = PTR_ERR(inode);
dev_err(dev, "%s: alloc_anon_inode failed rc=%d\n",
__func__, rc);
goto err3;
}
this.name = name;
this.len = strlen(name);
this.hash = 0;
path.dentry = d_alloc_pseudo(ocxlflash_vfs_mount->mnt_sb, &this);
if (!path.dentry) {
dev_err(dev, "%s: d_alloc_pseudo failed\n", __func__);
rc = -ENOMEM;
goto err4;
}
path.mnt = mntget(ocxlflash_vfs_mount);
d_instantiate(path.dentry, inode);
file = alloc_file(&path, OPEN_FMODE(flags), fops);
if (IS_ERR(file)) {
rc = PTR_ERR(file);
dev_err(dev, "%s: alloc_file failed rc=%d\n",
__func__, rc);
goto err5;
}
file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
file->private_data = priv;
out:
return file;
err5:
path_put(&path);
err4:
iput(inode);
err3:
simple_release_fs(&ocxlflash_vfs_mount, &ocxlflash_fs_cnt);
err2:
module_put(fops->owner);
err1:
file = ERR_PTR(rc);
goto out;
}
/**
* ocxlflash_set_master() - sets the context as master
* @ctx_cookie: Adapter context to set as master.
*/
static void ocxlflash_set_master(void *ctx_cookie)
{
struct ocxlflash_context *ctx = ctx_cookie;
ctx->master = true;
}
/**
* ocxlflash_get_context() - obtains the context associated with the host
* @pdev: PCI device associated with the host.
* @afu_cookie: Hardware AFU associated with the host.
*
* Return: returns the pointer to host adapter context
*/
static void *ocxlflash_get_context(struct pci_dev *pdev, void *afu_cookie)
{
struct ocxl_hw_afu *afu = afu_cookie;
return afu->ocxl_ctx;
}
/**
* ocxlflash_dev_context_init() - allocate and initialize an adapter context
* @pdev: PCI device associated with the host.
* @afu_cookie: Hardware AFU associated with the host.
*
* Return: returns the adapter context on success, ERR_PTR on failure
*/
static void *ocxlflash_dev_context_init(struct pci_dev *pdev, void *afu_cookie)
{
struct ocxl_hw_afu *afu = afu_cookie;
struct device *dev = afu->dev;
struct ocxlflash_context *ctx;
int rc;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (unlikely(!ctx)) {
dev_err(dev, "%s: Context allocation failed\n", __func__);
rc = -ENOMEM;
goto err1;
}
idr_preload(GFP_KERNEL);
rc = idr_alloc(&afu->idr, ctx, 0, afu->max_pasid, GFP_NOWAIT);
idr_preload_end();
if (unlikely(rc < 0)) {
dev_err(dev, "%s: idr_alloc failed rc=%d\n", __func__, rc);
goto err2;
}
ctx->pe = rc;
ctx->master = false;
ctx->mapping = NULL;
ctx->hw_afu = afu;
out:
return ctx;
err2:
kfree(ctx);
err1:
ctx = ERR_PTR(rc);
goto out;
}
/**
* ocxlflash_release_context() - releases an adapter context
* @ctx_cookie: Adapter context to be released.
*
* Return: 0 on success, -errno on failure
*/
static int ocxlflash_release_context(void *ctx_cookie)
{
struct ocxlflash_context *ctx = ctx_cookie;
int rc = 0;
if (!ctx)
goto out;
idr_remove(&ctx->hw_afu->idr, ctx->pe);
ocxlflash_release_mapping(ctx);
kfree(ctx);
out:
return rc;
}
/**
* ocxlflash_destroy_afu() - destroy the AFU structure
* @afu_cookie: AFU to be freed.
*/
static void ocxlflash_destroy_afu(void *afu_cookie)
{
struct ocxl_hw_afu *afu = afu_cookie;
if (!afu)
return;
ocxlflash_release_context(afu->ocxl_ctx);
idr_destroy(&afu->idr);
kfree(afu);
}
/**
* ocxlflash_config_fn() - configure the host function
* @pdev: PCI device associated with the host.
* @afu: AFU associated with the host.
*
* Return: 0 on success, -errno on failure
*/
static int ocxlflash_config_fn(struct pci_dev *pdev, struct ocxl_hw_afu *afu)
{
struct ocxl_fn_config *fcfg = &afu->fcfg;
struct device *dev = &pdev->dev;
u16 base, enabled, supported;
int rc = 0;
/* Read DVSEC config of the function */
rc = ocxl_config_read_function(pdev, fcfg);
if (unlikely(rc)) {
dev_err(dev, "%s: ocxl_config_read_function failed rc=%d\n",
__func__, rc);
goto out;
}
/* Check if function has AFUs defined, only 1 per function supported */
if (fcfg->max_afu_index >= 0) {
afu->is_present = true;
if (fcfg->max_afu_index != 0)
dev_warn(dev, "%s: Unexpected AFU index value %d\n",
__func__, fcfg->max_afu_index);
}
rc = ocxl_config_get_actag_info(pdev, &base, &enabled, &supported);
if (unlikely(rc)) {
dev_err(dev, "%s: ocxl_config_get_actag_info failed rc=%d\n",
__func__, rc);
goto out;
}
afu->fn_actag_base = base;
afu->fn_actag_enabled = enabled;
ocxl_config_set_actag(pdev, fcfg->dvsec_function_pos, base, enabled);
dev_dbg(dev, "%s: Function acTag range base=%u enabled=%u\n",
__func__, base, enabled);
out:
return rc;
}
/**
* ocxlflash_config_afu() - configure the host AFU
* @pdev: PCI device associated with the host.
* @afu: AFU associated with the host.
*
* Must be called _after_ host function configuration.
*
* Return: 0 on success, -errno on failure
*/
static int ocxlflash_config_afu(struct pci_dev *pdev, struct ocxl_hw_afu *afu)
{
struct ocxl_afu_config *acfg = &afu->acfg;
struct ocxl_fn_config *fcfg = &afu->fcfg;
struct device *dev = &pdev->dev;
int count;
int base;
int pos;
int rc = 0;
/* This HW AFU function does not have any AFUs defined */
if (!afu->is_present)
goto out;
/* Read AFU config at index 0 */
rc = ocxl_config_read_afu(pdev, fcfg, acfg, 0);
if (unlikely(rc)) {
dev_err(dev, "%s: ocxl_config_read_afu failed rc=%d\n",
__func__, rc);
goto out;
}
/* Only one AFU per function is supported, so actag_base is same */
base = afu->fn_actag_base;
count = min_t(int, acfg->actag_supported, afu->fn_actag_enabled);
pos = acfg->dvsec_afu_control_pos;
ocxl_config_set_afu_actag(pdev, pos, base, count);
dev_dbg(dev, "%s: acTag base=%d enabled=%d\n", __func__, base, count);
afu->afu_actag_base = base;
afu->afu_actag_enabled = count;
afu->max_pasid = 1 << acfg->pasid_supported_log;
ocxl_config_set_afu_pasid(pdev, pos, 0, acfg->pasid_supported_log);
out:
return rc;
}
/**
* ocxlflash_create_afu() - create the AFU for OCXL
* @pdev: PCI device associated with the host.
*
* Return: AFU on success, NULL on failure
*/
static void *ocxlflash_create_afu(struct pci_dev *pdev)
{
struct device *dev = &pdev->dev;
struct ocxlflash_context *ctx;
struct ocxl_hw_afu *afu;
int rc;
afu = kzalloc(sizeof(*afu), GFP_KERNEL);
if (unlikely(!afu)) {
dev_err(dev, "%s: HW AFU allocation failed\n", __func__);
goto out;
}
afu->pdev = pdev;
afu->dev = dev;
idr_init(&afu->idr);
rc = ocxlflash_config_fn(pdev, afu);
if (unlikely(rc)) {
dev_err(dev, "%s: Function configuration failed rc=%d\n",
__func__, rc);
goto err1;
}
rc = ocxlflash_config_afu(pdev, afu);
if (unlikely(rc)) {
dev_err(dev, "%s: AFU configuration failed rc=%d\n",
__func__, rc);
goto err1;
}
ctx = ocxlflash_dev_context_init(pdev, afu);
if (IS_ERR(ctx)) {
rc = PTR_ERR(ctx);
dev_err(dev, "%s: ocxlflash_dev_context_init failed rc=%d\n",
__func__, rc);
goto err1;
}
afu->ocxl_ctx = ctx;
out:
return afu;
err1:
idr_destroy(&afu->idr);
kfree(afu);
afu = NULL;
goto out;
}
static const struct file_operations ocxl_afu_fops = {
.owner = THIS_MODULE,
};
/**
* ocxlflash_get_fd() - get file descriptor for an adapter context
* @ctx_cookie: Adapter context.
* @fops: File operations to be associated.
* @fd: File descriptor to be returned back.
*
* Return: pointer to the file on success, ERR_PTR on failure
*/
static struct file *ocxlflash_get_fd(void *ctx_cookie,
struct file_operations *fops, int *fd)
{
struct ocxlflash_context *ctx = ctx_cookie;
struct device *dev = ctx->hw_afu->dev;
struct file *file;
int flags, fdtmp;
int rc = 0;
char *name = NULL;
/* Only allow one fd per context */
if (ctx->mapping) {
dev_err(dev, "%s: Context is already mapped to an fd\n",
__func__);
rc = -EEXIST;
goto err1;
}
flags = O_RDWR | O_CLOEXEC;
/* This code is similar to anon_inode_getfd() */
rc = get_unused_fd_flags(flags);
if (unlikely(rc < 0)) {
dev_err(dev, "%s: get_unused_fd_flags failed rc=%d\n",
__func__, rc);
goto err1;
}
fdtmp = rc;
/* Use default ops if there is no fops */
if (!fops)
fops = (struct file_operations *)&ocxl_afu_fops;
name = kasprintf(GFP_KERNEL, "ocxlflash:%d", ctx->pe);
file = ocxlflash_getfile(dev, name, fops, ctx, flags);
kfree(name);
if (IS_ERR(file)) {
rc = PTR_ERR(file);
dev_err(dev, "%s: ocxlflash_getfile failed rc=%d\n",
__func__, rc);
goto err2;
}
ctx->mapping = file->f_mapping;
*fd = fdtmp;
out:
return file;
err2:
put_unused_fd(fdtmp);
err1:
file = ERR_PTR(rc);
goto out;
}
/* Backend ops to ocxlflash services */
const struct cxlflash_backend_ops cxlflash_ocxl_ops = {
.module = THIS_MODULE,
.set_master = ocxlflash_set_master,
.get_context = ocxlflash_get_context,
.dev_context_init = ocxlflash_dev_context_init,
.release_context = ocxlflash_release_context,
.create_afu = ocxlflash_create_afu,
.destroy_afu = ocxlflash_destroy_afu,
.get_fd = ocxlflash_get_fd,
};
|