diff options
| -rw-r--r-- | drivers/misc/mic/scif/scif_mmap.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/drivers/misc/mic/scif/scif_mmap.c b/drivers/misc/mic/scif/scif_mmap.c new file mode 100644 index 000000000000..49cb8f7b4672 --- /dev/null +++ b/drivers/misc/mic/scif/scif_mmap.c @@ -0,0 +1,699 @@ +/* + * Intel MIC Platform Software Stack (MPSS) + * + * Copyright(c) 2015 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * Intel SCIF driver. + * + */ +#include "scif_main.h" + +/* + * struct scif_vma_info - Information about a remote memory mapping + * created via scif_mmap(..) + * @vma: VM area struct + * @list: link to list of active vmas + */ +struct scif_vma_info { + struct vm_area_struct *vma; + struct list_head list; +}; + +void scif_recv_munmap(struct scif_dev *scifdev, struct scifmsg *msg) +{ + struct scif_rma_req req; + struct scif_window *window = NULL; + struct scif_window *recv_window = + (struct scif_window *)msg->payload[0]; + struct scif_endpt *ep; + + ep = (struct scif_endpt *)recv_window->ep; + req.out_window = &window; + req.offset = recv_window->offset; + req.prot = recv_window->prot; + req.nr_bytes = recv_window->nr_pages << PAGE_SHIFT; + req.type = SCIF_WINDOW_FULL; + req.head = &ep->rma_info.reg_list; + msg->payload[0] = ep->remote_ep; + + mutex_lock(&ep->rma_info.rma_lock); + /* Does a valid window exist? */ + if (scif_query_window(&req)) { + dev_err(&scifdev->sdev->dev, + "%s %d -ENXIO\n", __func__, __LINE__); + msg->uop = SCIF_UNREGISTER_ACK; + goto error; + } + + scif_put_window(window, window->nr_pages); + + if (!window->ref_count) { + atomic_inc(&ep->rma_info.tw_refcount); + ep->rma_info.async_list_del = 1; + list_del_init(&window->list); + scif_free_window_offset(ep, window, window->offset); + } +error: + mutex_unlock(&ep->rma_info.rma_lock); + if (window && !window->ref_count) + scif_queue_for_cleanup(window, &scif_info.rma); +} + +/* + * Remove valid remote memory mappings created via scif_mmap(..) from the + * process address space since the remote node is lost + */ +static void __scif_zap_mmaps(struct scif_endpt *ep) +{ + struct list_head *item; + struct scif_vma_info *info; + struct vm_area_struct *vma; + unsigned long size; + + spin_lock(&ep->lock); + list_for_each(item, &ep->rma_info.vma_list) { + info = list_entry(item, struct scif_vma_info, list); + vma = info->vma; + size = vma->vm_end - vma->vm_start; + zap_vma_ptes(vma, vma->vm_start, size); + dev_dbg(scif_info.mdev.this_device, + "%s ep %p zap vma %p size 0x%lx\n", + __func__, ep, info->vma, size); + } + spin_unlock(&ep->lock); +} + +/* + * Traverse the list of endpoints for a particular remote node and + * zap valid remote memory mappings since the remote node is lost + */ +static void _scif_zap_mmaps(int node, struct list_head *head) +{ + struct scif_endpt *ep; + struct list_head *item; + + mutex_lock(&scif_info.connlock); + list_for_each(item, head) { + ep = list_entry(item, struct scif_endpt, list); + if (ep->remote_dev->node == node) + __scif_zap_mmaps(ep); + } + mutex_unlock(&scif_info.connlock); +} + +/* + * Wrapper for removing remote memory mappings for a particular node. This API + * is called by peer nodes as part of handling a lost node. + */ +void scif_zap_mmaps(int node) +{ + _scif_zap_mmaps(node, &scif_info.connected); + _scif_zap_mmaps(node, &scif_info.disconnected); +} + +/* + * This API is only called while handling a lost node: + * a) Remote node is dead. + * b) Remote memory mappings have been zapped + * So we can traverse the remote_reg_list without any locks. Since + * the window has not yet been unregistered we can drop the ref count + * and queue it to the cleanup thread. + */ +static void __scif_cleanup_rma_for_zombies(struct scif_endpt *ep) +{ + struct list_head *pos, *tmp; + struct scif_window *window; + + list_for_each_safe(pos, tmp, &ep->rma_info.remote_reg_list) { + window = list_entry(pos, struct scif_window, list); + if (window->ref_count) + scif_put_window(window, window->nr_pages); + else + dev_err(scif_info.mdev.this_device, + "%s %d unexpected\n", + __func__, __LINE__); + if (!window->ref_count) { + atomic_inc(&ep->rma_info.tw_refcount); + list_del_init(&window->list); + scif_queue_for_cleanup(window, &scif_info.rma); + } + } +} + +/* Cleanup remote registration lists for zombie endpoints */ +void scif_cleanup_rma_for_zombies(int node) +{ + struct scif_endpt *ep; + struct list_head *item; + + mutex_lock(&scif_info.eplock); + list_for_each(item, &scif_info.zombie) { + ep = list_entry(item, struct scif_endpt, list); + if (ep->remote_dev && ep->remote_dev->node == node) + __scif_cleanup_rma_for_zombies(ep); + } + mutex_unlock(&scif_info.eplock); + flush_work(&scif_info.misc_work); +} + +/* Insert the VMA into the per endpoint VMA list */ +static int scif_insert_vma(struct scif_endpt *ep, struct vm_area_struct *vma) +{ + struct scif_vma_info *info; + int err = 0; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + err = -ENOMEM; + goto done; + } + info->vma = vma; + spin_lock(&ep->lock); + list_add_tail(&info->list, &ep->rma_info.vma_list); + spin_unlock(&ep->lock); +done: + return err; +} + +/* Delete the VMA from the per endpoint VMA list */ +static void scif_delete_vma(struct scif_endpt *ep, struct vm_area_struct *vma) +{ + struct list_head *item; + struct scif_vma_info *info; + + spin_lock(&ep->lock); + list_for_each(item, &ep->rma_info.vma_list) { + info = list_entry(item, struct scif_vma_info, list); + if (info->vma == vma) { + list_del(&info->list); + kfree(info); + break; + } + } + spin_unlock(&ep->lock); +} + +static phys_addr_t scif_get_phys(phys_addr_t phys, struct scif_endpt *ep) +{ + struct scif_dev *scifdev = (struct scif_dev *)ep->remote_dev; + struct scif_hw_dev *sdev = scifdev->sdev; + phys_addr_t out_phys, apt_base = 0; + + /* + * If the DMA address is card relative then we need to add the + * aperture base for mmap to work correctly + */ + if (!scifdev_self(scifdev) && sdev->aper && sdev->card_rel_da) + apt_base = sdev->aper->pa; + out_phys = apt_base + phys; + return out_phys; +} + +int scif_get_pages(scif_epd_t epd, off_t offset, size_t len, + struct scif_range **pages) +{ + struct scif_endpt *ep = (struct scif_endpt *)epd; + struct scif_rma_req req; + struct scif_window *window = NULL; + int nr_pages, err, i; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI get_pinned_pages: ep %p offset 0x%lx len 0x%lx\n", + ep, offset, len); + err = scif_verify_epd(ep); + if (err) + return err; + + if (!len || (offset < 0) || + (offset + len < offset) || + (ALIGN(offset, PAGE_SIZE) != offset) || + (ALIGN(len, PAGE_SIZE) != len)) + return -EINVAL; + + nr_pages = len >> PAGE_SHIFT; + + req.out_window = &window; + req.offset = offset; + req.prot = 0; + req.nr_bytes = len; + req.type = SCIF_WINDOW_SINGLE; + req.head = &ep->rma_info.remote_reg_list; + + mutex_lock(&ep->rma_info.rma_lock); + /* Does a valid window exist? */ + err = scif_query_window(&req); + if (err) { + dev_err(&ep->remote_dev->sdev->dev, + "%s %d err %d\n", __func__, __LINE__, err); + goto error; + } + + /* Allocate scif_range */ + *pages = kzalloc(sizeof(**pages), GFP_KERNEL); + if (!*pages) { + err = -ENOMEM; + goto error; + } + + /* Allocate phys addr array */ + (*pages)->phys_addr = scif_zalloc(nr_pages * sizeof(dma_addr_t)); + if (!((*pages)->phys_addr)) { + err = -ENOMEM; + goto error; + } + + if (scif_is_mgmt_node() && !scifdev_self(ep->remote_dev)) { + /* Allocate virtual address array */ + ((*pages)->va = scif_zalloc(nr_pages * sizeof(void *))); + if (!(*pages)->va) { + err = -ENOMEM; + goto error; + } + } + /* Populate the values */ + (*pages)->cookie = window; + (*pages)->nr_pages = nr_pages; + (*pages)->prot_flags = window->prot; + + for (i = 0; i < nr_pages; i++) { + (*pages)->phys_addr[i] = + __scif_off_to_dma_addr(window, offset + + (i * PAGE_SIZE)); + (*pages)->phys_addr[i] = scif_get_phys((*pages)->phys_addr[i], + ep); + if (scif_is_mgmt_node() && !scifdev_self(ep->remote_dev)) + (*pages)->va[i] = + ep->remote_dev->sdev->aper->va + + (*pages)->phys_addr[i] - + ep->remote_dev->sdev->aper->pa; + } + + scif_get_window(window, nr_pages); +error: + mutex_unlock(&ep->rma_info.rma_lock); + if (err) { + if (*pages) { + scif_free((*pages)->phys_addr, + nr_pages * sizeof(dma_addr_t)); + scif_free((*pages)->va, + nr_pages * sizeof(void *)); + kfree(*pages); + *pages = NULL; + } + dev_err(&ep->remote_dev->sdev->dev, + "%s %d err %d\n", __func__, __LINE__, err); + } + return err; +} +EXPORT_SYMBOL_GPL(scif_get_pages); + +int scif_put_pages(struct scif_range *pages) +{ + struct scif_endpt *ep; + struct scif_window *window; + struct scifmsg msg; + + if (!pages || !pages->cookie) + return -EINVAL; + + window = pages->cookie; + + if (!window || window->magic != SCIFEP_MAGIC) + return -EINVAL; + + ep = (struct scif_endpt *)window->ep; + /* + * If the state is SCIFEP_CONNECTED or SCIFEP_DISCONNECTED then the + * callee should be allowed to release references to the pages, + * else the endpoint was not connected in the first place, + * hence the ENOTCONN. + */ + if (ep->state != SCIFEP_CONNECTED && ep->state != SCIFEP_DISCONNECTED) + return -ENOTCONN; + + mutex_lock(&ep->rma_info.rma_lock); + + scif_put_window(window, pages->nr_pages); + + /* Initiate window destruction if ref count is zero */ + if (!window->ref_count) { + list_del(&window->list); + mutex_unlock(&ep->rma_info.rma_lock); + scif_drain_dma_intr(ep->remote_dev->sdev, + ep->rma_info.dma_chan); + /* Inform the peer about this window being destroyed. */ + msg.uop = SCIF_MUNMAP; + msg.src = ep->port; + msg.payload[0] = window->peer_window; + /* No error handling for notification messages */ + scif_nodeqp_send(ep->remote_dev, &msg); + /* Destroy this window from the peer's registered AS */ + scif_destroy_remote_window(window); + } else { + mutex_unlock(&ep->rma_info.rma_lock); + } + + scif_free(pages->phys_addr, pages->nr_pages * sizeof(dma_addr_t)); + scif_free(pages->va, pages->nr_pages * sizeof(void *)); + kfree(pages); + return 0; +} +EXPORT_SYMBOL_GPL(scif_put_pages); + +/* + * scif_rma_list_mmap: + * + * Traverse the remote registration list starting from start_window: + * 1) Create VtoP mappings via remap_pfn_range(..) + * 2) Once step 1) and 2) complete successfully then traverse the range of + * windows again and bump the reference count. + * RMA lock must be held. + */ +static int scif_rma_list_mmap(struct scif_window *start_window, s64 offset, + int nr_pages, struct vm_area_struct *vma) +{ + s64 end_offset, loop_offset = offset; + struct scif_window *window = start_window; + int loop_nr_pages, nr_pages_left = nr_pages; + struct scif_endpt *ep = (struct scif_endpt *)start_window->ep; + struct list_head *head = &ep->rma_info.remote_reg_list; + int i, err = 0; + dma_addr_t phys_addr; + struct scif_window_iter src_win_iter; + size_t contig_bytes = 0; + + might_sleep(); + list_for_each_entry_from(window, head, list) { + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + loop_nr_pages = min_t(int, + (end_offset - loop_offset) >> PAGE_SHIFT, + nr_pages_left); + scif_init_window_iter(window, &src_win_iter); + for (i = 0; i < loop_nr_pages; i++) { + phys_addr = scif_off_to_dma_addr(window, loop_offset, + &contig_bytes, + &src_win_iter); + phys_addr = scif_get_phys(phys_addr, ep); + err = remap_pfn_range(vma, + vma->vm_start + + loop_offset - offset, + phys_addr >> PAGE_SHIFT, + PAGE_SIZE, + vma->vm_page_prot); + if (err) + goto error; + loop_offset += PAGE_SIZE; + } + nr_pages_left -= loop_nr_pages; + if (!nr_pages_left) + break; + } + /* + * No more failures expected. Bump up the ref count for all + * the windows. Another traversal from start_window required + * for handling errors encountered across windows during + * remap_pfn_range(..). + */ + loop_offset = offset; + nr_pages_left = nr_pages; + window = start_window; + head = &ep->rma_info.remote_reg_list; + list_for_each_entry_from(window, head, list) { + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + loop_nr_pages = min_t(int, + (end_offset - loop_offset) >> PAGE_SHIFT, + nr_pages_left); + scif_get_window(window, loop_nr_pages); + nr_pages_left -= loop_nr_pages; + loop_offset += (loop_nr_pages << PAGE_SHIFT); + if (!nr_pages_left) + break; + } +error: + if (err) + dev_err(scif_info.mdev.this_device, + "%s %d err %d\n", __func__, __LINE__, err); + return err; +} + +/* + * scif_rma_list_munmap: + * + * Traverse the remote registration list starting from window: + * 1) Decrement ref count. + * 2) If the ref count drops to zero then send a SCIF_MUNMAP message to peer. + * RMA lock must be held. + */ +static void scif_rma_list_munmap(struct scif_window *start_window, + s64 offset, int nr_pages) +{ + struct scifmsg msg; + s64 loop_offset = offset, end_offset; + int loop_nr_pages, nr_pages_left = nr_pages; + struct scif_endpt *ep = (struct scif_endpt *)start_window->ep; + struct list_head *head = &ep->rma_info.remote_reg_list; + struct scif_window *window = start_window, *_window; + + msg.uop = SCIF_MUNMAP; + msg.src = ep->port; + loop_offset = offset; + nr_pages_left = nr_pages; + list_for_each_entry_safe_from(window, _window, head, list) { + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + loop_nr_pages = min_t(int, + (end_offset - loop_offset) >> PAGE_SHIFT, + nr_pages_left); + scif_put_window(window, loop_nr_pages); + if (!window->ref_count) { + struct scif_dev *rdev = ep->remote_dev; + + scif_drain_dma_intr(rdev->sdev, + ep->rma_info.dma_chan); + /* Inform the peer about this munmap */ + msg.payload[0] = window->peer_window; + /* No error handling for Notification messages. */ + scif_nodeqp_send(ep->remote_dev, &msg); + list_del(&window->list); + /* Destroy this window from the peer's registered AS */ + scif_destroy_remote_window(window); + } + nr_pages_left -= loop_nr_pages; + loop_offset += (loop_nr_pages << PAGE_SHIFT); + if (!nr_pages_left) + break; + } +} + +/* + * The private data field of each VMA used to mmap a remote window + * points to an instance of struct vma_pvt + */ +struct vma_pvt { + struct scif_endpt *ep; /* End point for remote window */ + s64 offset; /* offset within remote window */ + bool valid_offset; /* offset is valid only if the original + * mmap request was for a single page + * else the offset within the vma is + * the correct offset + */ + struct kref ref; +}; + +static void vma_pvt_release(struct kref *ref) +{ + struct vma_pvt *vmapvt = container_of(ref, struct vma_pvt, ref); + + kfree(vmapvt); +} + +/** + * scif_vma_open - VMA open driver callback + * @vma: VMM memory area. + * The open method is called by the kernel to allow the subsystem implementing + * the VMA to initialize the area. This method is invoked any time a new + * reference to the VMA is made (when a process forks, for example). + * The one exception happens when the VMA is first created by mmap; + * in this case, the driver's mmap method is called instead. + * This function is also invoked when an existing VMA is split by the kernel + * due to a call to munmap on a subset of the VMA resulting in two VMAs. + * The kernel invokes this function only on one of the two VMAs. + */ +static void scif_vma_open(struct vm_area_struct *vma) +{ + struct vma_pvt *vmapvt = vma->vm_private_data; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI vma open: vma_start 0x%lx vma_end 0x%lx\n", + vma->vm_start, vma->vm_end); + scif_insert_vma(vmapvt->ep, vma); + kref_get(&vmapvt->ref); +} + +/** + * scif_munmap - VMA close driver callback. + * @vma: VMM memory area. + * When an area is destroyed, the kernel calls its close operation. + * Note that there's no usage count associated with VMA's; the area + * is opened and closed exactly once by each process that uses it. + */ +static void scif_munmap(struct vm_area_struct *vma) +{ + struct scif_endpt *ep; + struct vma_pvt *vmapvt = vma->vm_private_data; + int nr_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + s64 offset; + struct scif_rma_req req; + struct scif_window *window = NULL; + int err; + + might_sleep(); + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI munmap: vma_start 0x%lx vma_end 0x%lx\n", + vma->vm_start, vma->vm_end); + ep = vmapvt->ep; + offset = vmapvt->valid_offset ? vmapvt->offset : + (vma->vm_pgoff) << PAGE_SHIFT; + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI munmap: ep %p nr_pages 0x%x offset 0x%llx\n", + ep, nr_pages, offset); + req.out_window = &window; + req.offset = offset; + req.nr_bytes = vma->vm_end - vma->vm_start; + req.prot = vma->vm_flags & (VM_READ | VM_WRITE); + req.type = SCIF_WINDOW_PARTIAL; + req.head = &ep->rma_info.remote_reg_list; + + mutex_lock(&ep->rma_info.rma_lock); + + err = scif_query_window(&req); + if (err) + dev_err(scif_info.mdev.this_device, + "%s %d err %d\n", __func__, __LINE__, err); + else + scif_rma_list_munmap(window, offset, nr_pages); + + mutex_unlock(&ep->rma_info.rma_lock); + /* + * The kernel probably zeroes these out but we still want + * to clean up our own mess just in case. + */ + vma->vm_ops = NULL; + vma->vm_private_data = NULL; + kref_put(&vmapvt->ref, vma_pvt_release); + scif_delete_vma(ep, vma); +} + +static const struct vm_operations_struct scif_vm_ops = { + .open = scif_vma_open, + .close = scif_munmap, +}; + +/** + * scif_mmap - Map pages in virtual address space to a remote window. + * @vma: VMM memory area. + * @epd: endpoint descriptor + * + * Return: Upon successful completion, scif_mmap() returns zero + * else an apt error is returned as documented in scif.h + */ +int scif_mmap(struct vm_area_struct *vma, scif_epd_t epd) +{ + struct scif_rma_req req; + struct scif_window *window = NULL; + struct scif_endpt *ep = (struct scif_endpt *)epd; + s64 start_offset = vma->vm_pgoff << PAGE_SHIFT; + int nr_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + int err; + struct vma_pvt *vmapvt; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI mmap: ep %p start_offset 0x%llx nr_pages 0x%x\n", + ep, start_offset, nr_pages); + err = scif_verify_epd(ep); + if (err) + return err; + + might_sleep(); + + err = scif_insert_vma(ep, vma); + if (err) + return err; + + vmapvt = kzalloc(sizeof(*vmapvt), GFP_KERNEL); + if (!vmapvt) { + scif_delete_vma(ep, vma); + return -ENOMEM; + } + + vmapvt->ep = ep; + kref_init(&vmapvt->ref); + + req.out_window = &window; + req.offset = start_offset; + req.nr_bytes = vma->vm_end - vma->vm_start; + req.prot = vma->vm_flags & (VM_READ | VM_WRITE); + req.type = SCIF_WINDOW_PARTIAL; + req.head = &ep->rma_info.remote_reg_list; + + mutex_lock(&ep->rma_info.rma_lock); + /* Does a valid window exist? */ + err = scif_query_window(&req); + if (err) { + dev_err(&ep->remote_dev->sdev->dev, + "%s %d err %d\n", __func__, __LINE__, err); + goto error_unlock; + } + + /* Default prot for loopback */ + if (!scifdev_self(ep->remote_dev)) + vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); + + /* + * VM_DONTCOPY - Do not copy this vma on fork + * VM_DONTEXPAND - Cannot expand with mremap() + * VM_RESERVED - Count as reserved_vm like IO + * VM_PFNMAP - Page-ranges managed without "struct page" + * VM_IO - Memory mapped I/O or similar + * + * We do not want to copy this VMA automatically on a fork(), + * expand this VMA due to mremap() or swap out these pages since + * the VMA is actually backed by physical pages in the remote + * node's physical memory and not via a struct page. + */ + vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP; + + if (!scifdev_self(ep->remote_dev)) + vma->vm_flags |= VM_IO | VM_PFNMAP; + + /* Map this range of windows */ + err = scif_rma_list_mmap(window, start_offset, nr_pages, vma); + if (err) { + dev_err(&ep->remote_dev->sdev->dev, + "%s %d err %d\n", __func__, __LINE__, err); + goto error_unlock; + } + /* Set up the driver call back */ + vma->vm_ops = &scif_vm_ops; + vma->vm_private_data = vmapvt; +error_unlock: + mutex_unlock(&ep->rma_info.rma_lock); + if (err) { + kfree(vmapvt); + dev_err(&ep->remote_dev->sdev->dev, + "%s %d err %d\n", __func__, __LINE__, err); + scif_delete_vma(ep, vma); + } + return err; +} |