diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/cxl/api.c | 138 | ||||
| -rw-r--r-- | drivers/misc/cxl/context.c | 17 | ||||
| -rw-r--r-- | drivers/misc/cxl/cxl.h | 6 | ||||
| -rw-r--r-- | drivers/misc/cxl/file.c | 5 |
4 files changed, 135 insertions, 31 deletions
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c index e2efc6489c6e..1b35e33d2434 100644 --- a/drivers/misc/cxl/api.c +++ b/drivers/misc/cxl/api.c @@ -9,18 +9,119 @@ #include <linux/pci.h> #include <linux/slab.h> -#include <linux/anon_inodes.h> #include <linux/file.h> #include <misc/cxl.h> -#include <linux/fs.h> #include <asm/pnv-pci.h> #include <linux/msi.h> +#include <linux/module.h> +#include <linux/mount.h> #include "cxl.h" +/* + * Since we want to track memory mappings to be able to force-unmap + * when the AFU is no longer reachable, we need an inode. For devices + * opened through the cxl user API, this is not a problem, but a + * userland process can also get a cxl fd through the cxl_get_fd() + * API, which is used by the cxlflash driver. + * + * Therefore we implement our own simple pseudo-filesystem and inode + * allocator. We don't use the anonymous inode, as we need the + * meta-data associated with it (address_space) and it is shared by + * other drivers/processes, so it could lead to cxl unmapping VMAs + * from random processes. + */ + +#define CXL_PSEUDO_FS_MAGIC 0x1697697f + +static int cxl_fs_cnt; +static struct vfsmount *cxl_vfs_mount; + +static const struct dentry_operations cxl_fs_dops = { + .d_dname = simple_dname, +}; + +static struct dentry *cxl_fs_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data) +{ + return mount_pseudo(fs_type, "cxl:", NULL, &cxl_fs_dops, + CXL_PSEUDO_FS_MAGIC); +} + +static struct file_system_type cxl_fs_type = { + .name = "cxl", + .owner = THIS_MODULE, + .mount = cxl_fs_mount, + .kill_sb = kill_anon_super, +}; + + +void cxl_release_mapping(struct cxl_context *ctx) +{ + if (ctx->kernelapi && ctx->mapping) + simple_release_fs(&cxl_vfs_mount, &cxl_fs_cnt); +} + +static struct file *cxl_getfile(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; + + /* strongly inspired by anon_inode_getfile() */ + + if (fops->owner && !try_module_get(fops->owner)) + return ERR_PTR(-ENOENT); + + rc = simple_pin_fs(&cxl_fs_type, &cxl_vfs_mount, &cxl_fs_cnt); + if (rc < 0) { + pr_err("Cannot mount cxl pseudo filesystem: %d\n", rc); + file = ERR_PTR(rc); + goto err_module; + } + + inode = alloc_anon_inode(cxl_vfs_mount->mnt_sb); + if (IS_ERR(inode)) { + file = ERR_CAST(inode); + goto err_fs; + } + + file = ERR_PTR(-ENOMEM); + this.name = name; + this.len = strlen(name); + this.hash = 0; + path.dentry = d_alloc_pseudo(cxl_vfs_mount->mnt_sb, &this); + if (!path.dentry) + goto err_inode; + + path.mnt = mntget(cxl_vfs_mount); + d_instantiate(path.dentry, inode); + + file = alloc_file(&path, OPEN_FMODE(flags), fops); + if (IS_ERR(file)) + goto err_dput; + file->f_flags = flags & (O_ACCMODE | O_NONBLOCK); + file->private_data = priv; + + return file; + +err_dput: + path_put(&path); +err_inode: + iput(inode); +err_fs: + simple_release_fs(&cxl_vfs_mount, &cxl_fs_cnt); +err_module: + module_put(fops->owner); + return file; +} + struct cxl_context *cxl_dev_context_init(struct pci_dev *dev) { - struct address_space *mapping; struct cxl_afu *afu; struct cxl_context *ctx; int rc; @@ -35,28 +136,13 @@ struct cxl_context *cxl_dev_context_init(struct pci_dev *dev) ctx->kernelapi = true; - /* - * Make our own address space since we won't have one from the - * filesystem like the user api has, and even if we do associate a file - * with this context we don't want to use the global anonymous inode's - * address space as that can invalidate unrelated users: - */ - mapping = kmalloc(sizeof(struct address_space), GFP_KERNEL); - if (!mapping) { - rc = -ENOMEM; - goto err_ctx; - } - address_space_init_once(mapping); - /* Make it a slave context. We can promote it later? */ - rc = cxl_context_init(ctx, afu, false, mapping); + rc = cxl_context_init(ctx, afu, false); if (rc) - goto err_mapping; + goto err_ctx; return ctx; -err_mapping: - kfree(mapping); err_ctx: kfree(ctx); return ERR_PTR(rc); @@ -337,6 +423,11 @@ struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops, { struct file *file; int rc, flags, fdtmp; + char *name = NULL; + + /* only allow one per context */ + if (ctx->mapping) + return ERR_PTR(-EEXIST); flags = O_RDWR | O_CLOEXEC; @@ -360,12 +451,13 @@ struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops, } else /* use default ops */ fops = (struct file_operations *)&afu_fops; - file = anon_inode_getfile("cxl", fops, ctx, flags); + name = kasprintf(GFP_KERNEL, "cxl:%d", ctx->pe); + file = cxl_getfile(name, fops, ctx, flags); + kfree(name); if (IS_ERR(file)) goto err_fd; - file->f_mapping = ctx->mapping; - + cxl_context_set_mapping(ctx, file->f_mapping); *fd = fdtmp; return file; diff --git a/drivers/misc/cxl/context.c b/drivers/misc/cxl/context.c index 5e506c19108a..ff5e7e8cb1d1 100644 --- a/drivers/misc/cxl/context.c +++ b/drivers/misc/cxl/context.c @@ -34,8 +34,7 @@ struct cxl_context *cxl_context_alloc(void) /* * Initialises a CXL context. */ -int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, - struct address_space *mapping) +int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master) { int i; @@ -44,7 +43,7 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, ctx->master = master; ctx->pid = ctx->glpid = NULL; /* Set in start work ioctl */ mutex_init(&ctx->mapping_lock); - ctx->mapping = mapping; + ctx->mapping = NULL; /* * Allocate the segment table before we put it in the IDR so that we @@ -114,6 +113,14 @@ int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, return 0; } +void cxl_context_set_mapping(struct cxl_context *ctx, + struct address_space *mapping) +{ + mutex_lock(&ctx->mapping_lock); + ctx->mapping = mapping; + mutex_unlock(&ctx->mapping_lock); +} + static int cxl_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf) { struct cxl_context *ctx = vma->vm_file->private_data; @@ -300,8 +307,6 @@ static void reclaim_ctx(struct rcu_head *rcu) if (ctx->ff_page) __free_page(ctx->ff_page); ctx->sstp = NULL; - if (ctx->kernelapi) - kfree(ctx->mapping); kfree(ctx->irq_bitmap); @@ -313,6 +318,8 @@ static void reclaim_ctx(struct rcu_head *rcu) void cxl_context_free(struct cxl_context *ctx) { + if (ctx->kernelapi && ctx->mapping) + cxl_release_mapping(ctx); mutex_lock(&ctx->afu->contexts_lock); idr_remove(&ctx->afu->contexts_idr, ctx->pe); mutex_unlock(&ctx->afu->contexts_lock); diff --git a/drivers/misc/cxl/cxl.h b/drivers/misc/cxl/cxl.h index a144073593fa..b24d76723fb0 100644 --- a/drivers/misc/cxl/cxl.h +++ b/drivers/misc/cxl/cxl.h @@ -817,8 +817,9 @@ void cxl_dump_debug_buffer(void *addr, size_t size); void init_cxl_native(void); struct cxl_context *cxl_context_alloc(void); -int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master, - struct address_space *mapping); +int cxl_context_init(struct cxl_context *ctx, struct cxl_afu *afu, bool master); +void cxl_context_set_mapping(struct cxl_context *ctx, + struct address_space *mapping); void cxl_context_free(struct cxl_context *ctx); int cxl_context_iomap(struct cxl_context *ctx, struct vm_area_struct *vma); unsigned int cxl_map_irq(struct cxl *adapter, irq_hw_number_t hwirq, @@ -877,6 +878,7 @@ void cxl_native_err_irq_dump_regs(struct cxl *adapter); void cxl_stop_trace(struct cxl *cxl); int cxl_pci_vphb_add(struct cxl_afu *afu); void cxl_pci_vphb_remove(struct cxl_afu *afu); +void cxl_release_mapping(struct cxl_context *ctx); extern struct pci_driver cxl_pci_driver; extern struct platform_driver cxl_of_driver; diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c index 77080cc5fa0a..859959f19f10 100644 --- a/drivers/misc/cxl/file.c +++ b/drivers/misc/cxl/file.c @@ -86,9 +86,12 @@ static int __afu_open(struct inode *inode, struct file *file, bool master) goto err_put_afu; } - if ((rc = cxl_context_init(ctx, afu, master, inode->i_mapping))) + rc = cxl_context_init(ctx, afu, master); + if (rc) goto err_put_afu; + cxl_context_set_mapping(ctx, inode->i_mapping); + pr_devel("afu_open pe: %i\n", ctx->pe); file->private_data = ctx; cxl_ctx_get(); |