diff options
Diffstat (limited to 'drivers/misc/cxl/api.c')
-rw-r--r-- | drivers/misc/cxl/api.c | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c new file mode 100644 index 0000000000..d85c565308 --- /dev/null +++ b/drivers/misc/cxl/api.c @@ -0,0 +1,532 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright 2014 IBM Corp. + */ + +#include <linux/pci.h> +#include <linux/slab.h> +#include <linux/file.h> +#include <misc/cxl.h> +#include <linux/module.h> +#include <linux/mount.h> +#include <linux/pseudo_fs.h> +#include <linux/sched/mm.h> +#include <linux/mmu_context.h> +#include <linux/irqdomain.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 int cxl_fs_init_fs_context(struct fs_context *fc) +{ + return init_pseudo(fc, CXL_PSEUDO_FS_MAGIC) ? 0 : -ENOMEM; +} + +static struct file_system_type cxl_fs_type = { + .name = "cxl", + .owner = THIS_MODULE, + .init_fs_context = cxl_fs_init_fs_context, + .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 file *file; + struct inode *inode; + 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 = alloc_file_pseudo(inode, cxl_vfs_mount, name, + flags & (O_ACCMODE | O_NONBLOCK), fops); + if (IS_ERR(file)) + goto err_inode; + + file->private_data = priv; + + return file; + +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 cxl_afu *afu; + struct cxl_context *ctx; + int rc; + + afu = cxl_pci_to_afu(dev); + if (IS_ERR(afu)) + return ERR_CAST(afu); + + ctx = cxl_context_alloc(); + if (!ctx) + return ERR_PTR(-ENOMEM); + + ctx->kernelapi = true; + + /* Make it a slave context. We can promote it later? */ + rc = cxl_context_init(ctx, afu, false); + if (rc) + goto err_ctx; + + return ctx; + +err_ctx: + kfree(ctx); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(cxl_dev_context_init); + +struct cxl_context *cxl_get_context(struct pci_dev *dev) +{ + return dev->dev.archdata.cxl_ctx; +} +EXPORT_SYMBOL_GPL(cxl_get_context); + +int cxl_release_context(struct cxl_context *ctx) +{ + if (ctx->status >= STARTED) + return -EBUSY; + + cxl_context_free(ctx); + + return 0; +} +EXPORT_SYMBOL_GPL(cxl_release_context); + +static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num) +{ + __u16 range; + int r; + + for (r = 0; r < CXL_IRQ_RANGES; r++) { + range = ctx->irqs.range[r]; + if (num < range) { + return ctx->irqs.offset[r] + num; + } + num -= range; + } + return 0; +} + + +int cxl_set_priv(struct cxl_context *ctx, void *priv) +{ + if (!ctx) + return -EINVAL; + + ctx->priv = priv; + + return 0; +} +EXPORT_SYMBOL_GPL(cxl_set_priv); + +void *cxl_get_priv(struct cxl_context *ctx) +{ + if (!ctx) + return ERR_PTR(-EINVAL); + + return ctx->priv; +} +EXPORT_SYMBOL_GPL(cxl_get_priv); + +int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num) +{ + int res; + irq_hw_number_t hwirq; + + if (num == 0) + num = ctx->afu->pp_irqs; + res = afu_allocate_irqs(ctx, num); + if (res) + return res; + + if (!cpu_has_feature(CPU_FTR_HVMODE)) { + /* In a guest, the PSL interrupt is not multiplexed. It was + * allocated above, and we need to set its handler + */ + hwirq = cxl_find_afu_irq(ctx, 0); + if (hwirq) + cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl"); + } + + if (ctx->status == STARTED) { + if (cxl_ops->update_ivtes) + cxl_ops->update_ivtes(ctx); + else WARN(1, "BUG: cxl_allocate_afu_irqs must be called prior to starting the context on this platform\n"); + } + + return res; +} +EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs); + +void cxl_free_afu_irqs(struct cxl_context *ctx) +{ + irq_hw_number_t hwirq; + unsigned int virq; + + if (!cpu_has_feature(CPU_FTR_HVMODE)) { + hwirq = cxl_find_afu_irq(ctx, 0); + if (hwirq) { + virq = irq_find_mapping(NULL, hwirq); + if (virq) + cxl_unmap_irq(virq, ctx); + } + } + afu_irq_name_free(ctx); + cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter); +} +EXPORT_SYMBOL_GPL(cxl_free_afu_irqs); + +int cxl_map_afu_irq(struct cxl_context *ctx, int num, + irq_handler_t handler, void *cookie, char *name) +{ + irq_hw_number_t hwirq; + + /* + * Find interrupt we are to register. + */ + hwirq = cxl_find_afu_irq(ctx, num); + if (!hwirq) + return -ENOENT; + + return cxl_map_irq(ctx->afu->adapter, hwirq, handler, cookie, name); +} +EXPORT_SYMBOL_GPL(cxl_map_afu_irq); + +void cxl_unmap_afu_irq(struct cxl_context *ctx, int num, void *cookie) +{ + irq_hw_number_t hwirq; + unsigned int virq; + + hwirq = cxl_find_afu_irq(ctx, num); + if (!hwirq) + return; + + virq = irq_find_mapping(NULL, hwirq); + if (virq) + cxl_unmap_irq(virq, cookie); +} +EXPORT_SYMBOL_GPL(cxl_unmap_afu_irq); + +/* + * Start a context + * Code here similar to afu_ioctl_start_work(). + */ +int cxl_start_context(struct cxl_context *ctx, u64 wed, + struct task_struct *task) +{ + int rc = 0; + bool kernel = true; + + pr_devel("%s: pe: %i\n", __func__, ctx->pe); + + mutex_lock(&ctx->status_mutex); + if (ctx->status == STARTED) + goto out; /* already started */ + + /* + * Increment the mapped context count for adapter. This also checks + * if adapter_context_lock is taken. + */ + rc = cxl_adapter_context_get(ctx->afu->adapter); + if (rc) + goto out; + + if (task) { + ctx->pid = get_task_pid(task, PIDTYPE_PID); + kernel = false; + + /* acquire a reference to the task's mm */ + ctx->mm = get_task_mm(current); + + /* ensure this mm_struct can't be freed */ + cxl_context_mm_count_get(ctx); + + if (ctx->mm) { + /* decrement the use count from above */ + mmput(ctx->mm); + /* make TLBIs for this context global */ + mm_context_add_copro(ctx->mm); + } + } + + /* + * Increment driver use count. Enables global TLBIs for hash + * and callbacks to handle the segment table + */ + cxl_ctx_get(); + + /* See the comment in afu_ioctl_start_work() */ + smp_mb(); + + if ((rc = cxl_ops->attach_process(ctx, kernel, wed, 0))) { + put_pid(ctx->pid); + ctx->pid = NULL; + cxl_adapter_context_put(ctx->afu->adapter); + cxl_ctx_put(); + if (task) { + cxl_context_mm_count_put(ctx); + if (ctx->mm) + mm_context_remove_copro(ctx->mm); + } + goto out; + } + + ctx->status = STARTED; +out: + mutex_unlock(&ctx->status_mutex); + return rc; +} +EXPORT_SYMBOL_GPL(cxl_start_context); + +int cxl_process_element(struct cxl_context *ctx) +{ + return ctx->external_pe; +} +EXPORT_SYMBOL_GPL(cxl_process_element); + +/* Stop a context. Returns 0 on success, otherwise -Errno */ +int cxl_stop_context(struct cxl_context *ctx) +{ + return __detach_context(ctx); +} +EXPORT_SYMBOL_GPL(cxl_stop_context); + +void cxl_set_master(struct cxl_context *ctx) +{ + ctx->master = true; +} +EXPORT_SYMBOL_GPL(cxl_set_master); + +/* wrappers around afu_* file ops which are EXPORTED */ +int cxl_fd_open(struct inode *inode, struct file *file) +{ + return afu_open(inode, file); +} +EXPORT_SYMBOL_GPL(cxl_fd_open); +int cxl_fd_release(struct inode *inode, struct file *file) +{ + return afu_release(inode, file); +} +EXPORT_SYMBOL_GPL(cxl_fd_release); +long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + return afu_ioctl(file, cmd, arg); +} +EXPORT_SYMBOL_GPL(cxl_fd_ioctl); +int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm) +{ + return afu_mmap(file, vm); +} +EXPORT_SYMBOL_GPL(cxl_fd_mmap); +__poll_t cxl_fd_poll(struct file *file, struct poll_table_struct *poll) +{ + return afu_poll(file, poll); +} +EXPORT_SYMBOL_GPL(cxl_fd_poll); +ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count, + loff_t *off) +{ + return afu_read(file, buf, count, off); +} +EXPORT_SYMBOL_GPL(cxl_fd_read); + +#define PATCH_FOPS(NAME) if (!fops->NAME) fops->NAME = afu_fops.NAME + +/* Get a struct file and fd for a context and attach the ops */ +struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops, + int *fd) +{ + 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; + + /* This code is similar to anon_inode_getfd() */ + rc = get_unused_fd_flags(flags); + if (rc < 0) + return ERR_PTR(rc); + fdtmp = rc; + + /* + * Patch the file ops. Needs to be careful that this is rentrant safe. + */ + if (fops) { + PATCH_FOPS(open); + PATCH_FOPS(poll); + PATCH_FOPS(read); + PATCH_FOPS(release); + PATCH_FOPS(unlocked_ioctl); + PATCH_FOPS(compat_ioctl); + PATCH_FOPS(mmap); + } else /* use default ops */ + fops = (struct file_operations *)&afu_fops; + + name = kasprintf(GFP_KERNEL, "cxl:%d", ctx->pe); + file = cxl_getfile(name, fops, ctx, flags); + kfree(name); + if (IS_ERR(file)) + goto err_fd; + + cxl_context_set_mapping(ctx, file->f_mapping); + *fd = fdtmp; + return file; + +err_fd: + put_unused_fd(fdtmp); + return NULL; +} +EXPORT_SYMBOL_GPL(cxl_get_fd); + +struct cxl_context *cxl_fops_get_context(struct file *file) +{ + return file->private_data; +} +EXPORT_SYMBOL_GPL(cxl_fops_get_context); + +void cxl_set_driver_ops(struct cxl_context *ctx, + struct cxl_afu_driver_ops *ops) +{ + WARN_ON(!ops->fetch_event || !ops->event_delivered); + atomic_set(&ctx->afu_driver_events, 0); + ctx->afu_driver_ops = ops; +} +EXPORT_SYMBOL_GPL(cxl_set_driver_ops); + +void cxl_context_events_pending(struct cxl_context *ctx, + unsigned int new_events) +{ + atomic_add(new_events, &ctx->afu_driver_events); + wake_up_all(&ctx->wq); +} +EXPORT_SYMBOL_GPL(cxl_context_events_pending); + +int cxl_start_work(struct cxl_context *ctx, + struct cxl_ioctl_start_work *work) +{ + int rc; + + /* code taken from afu_ioctl_start_work */ + 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)) { + return -EINVAL; + } + + rc = afu_register_irqs(ctx, work->num_interrupts); + if (rc) + return rc; + + rc = cxl_start_context(ctx, work->work_element_descriptor, current); + if (rc < 0) { + afu_release_irqs(ctx, ctx); + return rc; + } + + return 0; +} +EXPORT_SYMBOL_GPL(cxl_start_work); + +void __iomem *cxl_psa_map(struct cxl_context *ctx) +{ + if (ctx->status != STARTED) + return NULL; + + pr_devel("%s: psn_phys%llx size:%llx\n", + __func__, ctx->psn_phys, ctx->psn_size); + return ioremap(ctx->psn_phys, ctx->psn_size); +} +EXPORT_SYMBOL_GPL(cxl_psa_map); + +void cxl_psa_unmap(void __iomem *addr) +{ + iounmap(addr); +} +EXPORT_SYMBOL_GPL(cxl_psa_unmap); + +int cxl_afu_reset(struct cxl_context *ctx) +{ + struct cxl_afu *afu = ctx->afu; + int rc; + + rc = cxl_ops->afu_reset(afu); + if (rc) + return rc; + + return cxl_ops->afu_check_and_enable(afu); +} +EXPORT_SYMBOL_GPL(cxl_afu_reset); + +void cxl_perst_reloads_same_image(struct cxl_afu *afu, + bool perst_reloads_same_image) +{ + afu->adapter->perst_same_image = perst_reloads_same_image; +} +EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image); + +ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count) +{ + struct cxl_afu *afu = cxl_pci_to_afu(dev); + if (IS_ERR(afu)) + return -ENODEV; + + return cxl_ops->read_adapter_vpd(afu->adapter, buf, count); +} +EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd); |