diff options
Diffstat (limited to 'drivers/misc/mic/scif/scif_dma.c')
| -rw-r--r-- | drivers/misc/mic/scif/scif_dma.c | 1979 |
1 files changed, 1979 insertions, 0 deletions
diff --git a/drivers/misc/mic/scif/scif_dma.c b/drivers/misc/mic/scif/scif_dma.c new file mode 100644 index 000000000000..95a13c629a8e --- /dev/null +++ b/drivers/misc/mic/scif/scif_dma.c @@ -0,0 +1,1979 @@ +/* + * 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" +#include "scif_map.h" + +/* + * struct scif_dma_comp_cb - SCIF DMA completion callback + * + * @dma_completion_func: DMA completion callback + * @cb_cookie: DMA completion callback cookie + * @temp_buf: Temporary buffer + * @temp_buf_to_free: Temporary buffer to be freed + * @is_cache: Is a kmem_cache allocated buffer + * @dst_offset: Destination registration offset + * @dst_window: Destination registration window + * @len: Length of the temp buffer + * @temp_phys: DMA address of the temp buffer + * @sdev: The SCIF device + * @header_padding: padding for cache line alignment + */ +struct scif_dma_comp_cb { + void (*dma_completion_func)(void *cookie); + void *cb_cookie; + u8 *temp_buf; + u8 *temp_buf_to_free; + bool is_cache; + s64 dst_offset; + struct scif_window *dst_window; + size_t len; + dma_addr_t temp_phys; + struct scif_dev *sdev; + int header_padding; +}; + +/** + * struct scif_copy_work - Work for DMA copy + * + * @src_offset: Starting source offset + * @dst_offset: Starting destination offset + * @src_window: Starting src registered window + * @dst_window: Starting dst registered window + * @loopback: true if this is a loopback DMA transfer + * @len: Length of the transfer + * @comp_cb: DMA copy completion callback + * @remote_dev: The remote SCIF peer device + * @fence_type: polling or interrupt based + * @ordered: is this a tail byte ordered DMA transfer + */ +struct scif_copy_work { + s64 src_offset; + s64 dst_offset; + struct scif_window *src_window; + struct scif_window *dst_window; + int loopback; + size_t len; + struct scif_dma_comp_cb *comp_cb; + struct scif_dev *remote_dev; + int fence_type; + bool ordered; +}; + +#ifndef list_entry_next +#define list_entry_next(pos, member) \ + list_entry(pos->member.next, typeof(*pos), member) +#endif + +/** + * scif_reserve_dma_chan: + * @ep: Endpoint Descriptor. + * + * This routine reserves a DMA channel for a particular + * endpoint. All DMA transfers for an endpoint are always + * programmed on the same DMA channel. + */ +int scif_reserve_dma_chan(struct scif_endpt *ep) +{ + int err = 0; + struct scif_dev *scifdev; + struct scif_hw_dev *sdev; + struct dma_chan *chan; + + /* Loopback DMAs are not supported on the management node */ + if (!scif_info.nodeid && scifdev_self(ep->remote_dev)) + return 0; + if (scif_info.nodeid) + scifdev = &scif_dev[0]; + else + scifdev = ep->remote_dev; + sdev = scifdev->sdev; + if (!sdev->num_dma_ch) + return -ENODEV; + chan = sdev->dma_ch[scifdev->dma_ch_idx]; + scifdev->dma_ch_idx = (scifdev->dma_ch_idx + 1) % sdev->num_dma_ch; + mutex_lock(&ep->rma_info.rma_lock); + ep->rma_info.dma_chan = chan; + mutex_unlock(&ep->rma_info.rma_lock); + return err; +} + +#ifdef CONFIG_MMU_NOTIFIER +/** + * scif_rma_destroy_tcw: + * + * This routine destroys temporary cached windows + */ +static +void __scif_rma_destroy_tcw(struct scif_mmu_notif *mmn, + struct scif_endpt *ep, + u64 start, u64 len) +{ + struct list_head *item, *tmp; + struct scif_window *window; + u64 start_va, end_va; + u64 end = start + len; + + if (end <= start) + return; + + list_for_each_safe(item, tmp, &mmn->tc_reg_list) { + window = list_entry(item, struct scif_window, list); + ep = (struct scif_endpt *)window->ep; + if (!len) + break; + start_va = window->va_for_temp; + end_va = start_va + (window->nr_pages << PAGE_SHIFT); + if (start < start_va && end <= start_va) + break; + if (start >= end_va) + continue; + __scif_rma_destroy_tcw_helper(window); + } +} + +static void scif_rma_destroy_tcw(struct scif_mmu_notif *mmn, u64 start, u64 len) +{ + struct scif_endpt *ep = mmn->ep; + + spin_lock(&ep->rma_info.tc_lock); + __scif_rma_destroy_tcw(mmn, ep, start, len); + spin_unlock(&ep->rma_info.tc_lock); +} + +static void scif_rma_destroy_tcw_ep(struct scif_endpt *ep) +{ + struct list_head *item, *tmp; + struct scif_mmu_notif *mmn; + + list_for_each_safe(item, tmp, &ep->rma_info.mmn_list) { + mmn = list_entry(item, struct scif_mmu_notif, list); + scif_rma_destroy_tcw(mmn, 0, ULONG_MAX); + } +} + +static void __scif_rma_destroy_tcw_ep(struct scif_endpt *ep) +{ + struct list_head *item, *tmp; + struct scif_mmu_notif *mmn; + + spin_lock(&ep->rma_info.tc_lock); + list_for_each_safe(item, tmp, &ep->rma_info.mmn_list) { + mmn = list_entry(item, struct scif_mmu_notif, list); + __scif_rma_destroy_tcw(mmn, ep, 0, ULONG_MAX); + } + spin_unlock(&ep->rma_info.tc_lock); +} + +static bool scif_rma_tc_can_cache(struct scif_endpt *ep, size_t cur_bytes) +{ + if ((cur_bytes >> PAGE_SHIFT) > scif_info.rma_tc_limit) + return false; + if ((atomic_read(&ep->rma_info.tcw_total_pages) + + (cur_bytes >> PAGE_SHIFT)) > + scif_info.rma_tc_limit) { + dev_info(scif_info.mdev.this_device, + "%s %d total=%d, current=%zu reached max\n", + __func__, __LINE__, + atomic_read(&ep->rma_info.tcw_total_pages), + (1 + (cur_bytes >> PAGE_SHIFT))); + scif_rma_destroy_tcw_invalid(); + __scif_rma_destroy_tcw_ep(ep); + } + return true; +} + +static void scif_mmu_notifier_release(struct mmu_notifier *mn, + struct mm_struct *mm) +{ + struct scif_mmu_notif *mmn; + + mmn = container_of(mn, struct scif_mmu_notif, ep_mmu_notifier); + scif_rma_destroy_tcw(mmn, 0, ULONG_MAX); + schedule_work(&scif_info.misc_work); +} + +static void scif_mmu_notifier_invalidate_page(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long address) +{ + struct scif_mmu_notif *mmn; + + mmn = container_of(mn, struct scif_mmu_notif, ep_mmu_notifier); + scif_rma_destroy_tcw(mmn, address, PAGE_SIZE); +} + +static void scif_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, + unsigned long end) +{ + struct scif_mmu_notif *mmn; + + mmn = container_of(mn, struct scif_mmu_notif, ep_mmu_notifier); + scif_rma_destroy_tcw(mmn, start, end - start); +} + +static void scif_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn, + struct mm_struct *mm, + unsigned long start, + unsigned long end) +{ + /* + * Nothing to do here, everything needed was done in + * invalidate_range_start. + */ +} + +static const struct mmu_notifier_ops scif_mmu_notifier_ops = { + .release = scif_mmu_notifier_release, + .clear_flush_young = NULL, + .invalidate_page = scif_mmu_notifier_invalidate_page, + .invalidate_range_start = scif_mmu_notifier_invalidate_range_start, + .invalidate_range_end = scif_mmu_notifier_invalidate_range_end}; + +static void scif_ep_unregister_mmu_notifier(struct scif_endpt *ep) +{ + struct scif_endpt_rma_info *rma = &ep->rma_info; + struct scif_mmu_notif *mmn = NULL; + struct list_head *item, *tmp; + + mutex_lock(&ep->rma_info.mmn_lock); + list_for_each_safe(item, tmp, &rma->mmn_list) { + mmn = list_entry(item, struct scif_mmu_notif, list); + mmu_notifier_unregister(&mmn->ep_mmu_notifier, mmn->mm); + list_del(item); + kfree(mmn); + } + mutex_unlock(&ep->rma_info.mmn_lock); +} + +static void scif_init_mmu_notifier(struct scif_mmu_notif *mmn, + struct mm_struct *mm, struct scif_endpt *ep) +{ + mmn->ep = ep; + mmn->mm = mm; + mmn->ep_mmu_notifier.ops = &scif_mmu_notifier_ops; + INIT_LIST_HEAD(&mmn->list); + INIT_LIST_HEAD(&mmn->tc_reg_list); +} + +static struct scif_mmu_notif * +scif_find_mmu_notifier(struct mm_struct *mm, struct scif_endpt_rma_info *rma) +{ + struct scif_mmu_notif *mmn; + struct list_head *item; + + list_for_each(item, &rma->mmn_list) { + mmn = list_entry(item, struct scif_mmu_notif, list); + if (mmn->mm == mm) + return mmn; + } + return NULL; +} + +static struct scif_mmu_notif * +scif_add_mmu_notifier(struct mm_struct *mm, struct scif_endpt *ep) +{ + struct scif_mmu_notif *mmn + = kzalloc(sizeof(*mmn), GFP_KERNEL); + + if (!mmn) + return ERR_PTR(ENOMEM); + + scif_init_mmu_notifier(mmn, current->mm, ep); + if (mmu_notifier_register(&mmn->ep_mmu_notifier, + current->mm)) { + kfree(mmn); + return ERR_PTR(EBUSY); + } + list_add(&mmn->list, &ep->rma_info.mmn_list); + return mmn; +} + +/* + * Called from the misc thread to destroy temporary cached windows and + * unregister the MMU notifier for the SCIF endpoint. + */ +void scif_mmu_notif_handler(struct work_struct *work) +{ + struct list_head *pos, *tmpq; + struct scif_endpt *ep; +restart: + scif_rma_destroy_tcw_invalid(); + spin_lock(&scif_info.rmalock); + list_for_each_safe(pos, tmpq, &scif_info.mmu_notif_cleanup) { + ep = list_entry(pos, struct scif_endpt, mmu_list); + list_del(&ep->mmu_list); + spin_unlock(&scif_info.rmalock); + scif_rma_destroy_tcw_ep(ep); + scif_ep_unregister_mmu_notifier(ep); + goto restart; + } + spin_unlock(&scif_info.rmalock); +} + +static bool scif_is_set_reg_cache(int flags) +{ + return !!(flags & SCIF_RMA_USECACHE); +} +#else +static struct scif_mmu_notif * +scif_find_mmu_notifier(struct mm_struct *mm, + struct scif_endpt_rma_info *rma) +{ + return NULL; +} + +static struct scif_mmu_notif * +scif_add_mmu_notifier(struct mm_struct *mm, struct scif_endpt *ep) +{ + return NULL; +} + +void scif_mmu_notif_handler(struct work_struct *work) +{ +} + +static bool scif_is_set_reg_cache(int flags) +{ + return false; +} + +static bool scif_rma_tc_can_cache(struct scif_endpt *ep, size_t cur_bytes) +{ + return false; +} +#endif + +/** + * scif_register_temp: + * @epd: End Point Descriptor. + * @addr: virtual address to/from which to copy + * @len: length of range to copy + * @out_offset: computed offset returned by reference. + * @out_window: allocated registered window returned by reference. + * + * Create a temporary registered window. The peer will not know about this + * window. This API is used for scif_vreadfrom()/scif_vwriteto() API's. + */ +static int +scif_register_temp(scif_epd_t epd, unsigned long addr, size_t len, int prot, + off_t *out_offset, struct scif_window **out_window) +{ + struct scif_endpt *ep = (struct scif_endpt *)epd; + int err; + scif_pinned_pages_t pinned_pages; + size_t aligned_len; + + aligned_len = ALIGN(len, PAGE_SIZE); + + err = __scif_pin_pages((void *)(addr & PAGE_MASK), + aligned_len, &prot, 0, &pinned_pages); + if (err) + return err; + + pinned_pages->prot = prot; + + /* Compute the offset for this registration */ + err = scif_get_window_offset(ep, 0, 0, + aligned_len >> PAGE_SHIFT, + (s64 *)out_offset); + if (err) + goto error_unpin; + + /* Allocate and prepare self registration window */ + *out_window = scif_create_window(ep, aligned_len >> PAGE_SHIFT, + *out_offset, true); + if (!*out_window) { + scif_free_window_offset(ep, NULL, *out_offset); + err = -ENOMEM; + goto error_unpin; + } + + (*out_window)->pinned_pages = pinned_pages; + (*out_window)->nr_pages = pinned_pages->nr_pages; + (*out_window)->prot = pinned_pages->prot; + + (*out_window)->va_for_temp = addr & PAGE_MASK; + err = scif_map_window(ep->remote_dev, *out_window); + if (err) { + /* Something went wrong! Rollback */ + scif_destroy_window(ep, *out_window); + *out_window = NULL; + } else { + *out_offset |= (addr - (*out_window)->va_for_temp); + } + return err; +error_unpin: + if (err) + dev_err(&ep->remote_dev->sdev->dev, + "%s %d err %d\n", __func__, __LINE__, err); + scif_unpin_pages(pinned_pages); + return err; +} + +#define SCIF_DMA_TO (3 * HZ) + +/* + * scif_sync_dma - Program a DMA without an interrupt descriptor + * + * @dev - The address of the pointer to the device instance used + * for DMA registration. + * @chan - DMA channel to be used. + * @sync_wait: Wait for DMA to complete? + * + * Return 0 on success and -errno on error. + */ +static int scif_sync_dma(struct scif_hw_dev *sdev, struct dma_chan *chan, + bool sync_wait) +{ + int err = 0; + struct dma_async_tx_descriptor *tx = NULL; + enum dma_ctrl_flags flags = DMA_PREP_FENCE; + dma_cookie_t cookie; + struct dma_device *ddev; + + if (!chan) { + err = -EIO; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + return err; + } + ddev = chan->device; + + tx = ddev->device_prep_dma_memcpy(chan, 0, 0, 0, flags); + if (!tx) { + err = -ENOMEM; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + goto release; + } + cookie = tx->tx_submit(tx); + + if (dma_submit_error(cookie)) { + err = -ENOMEM; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + goto release; + } + if (!sync_wait) { + dma_async_issue_pending(chan); + } else { + if (dma_sync_wait(chan, cookie) == DMA_COMPLETE) { + err = 0; + } else { + err = -EIO; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + } + } +release: + return err; +} + +static void scif_dma_callback(void *arg) +{ + struct completion *done = (struct completion *)arg; + + complete(done); +} + +#define SCIF_DMA_SYNC_WAIT true +#define SCIF_DMA_POLL BIT(0) +#define SCIF_DMA_INTR BIT(1) + +/* + * scif_async_dma - Program a DMA with an interrupt descriptor + * + * @dev - The address of the pointer to the device instance used + * for DMA registration. + * @chan - DMA channel to be used. + * Return 0 on success and -errno on error. + */ +static int scif_async_dma(struct scif_hw_dev *sdev, struct dma_chan *chan) +{ + int err = 0; + struct dma_device *ddev; + struct dma_async_tx_descriptor *tx = NULL; + enum dma_ctrl_flags flags = DMA_PREP_INTERRUPT | DMA_PREP_FENCE; + DECLARE_COMPLETION_ONSTACK(done_wait); + dma_cookie_t cookie; + enum dma_status status; + + if (!chan) { + err = -EIO; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + return err; + } + ddev = chan->device; + + tx = ddev->device_prep_dma_memcpy(chan, 0, 0, 0, flags); + if (!tx) { + err = -ENOMEM; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + goto release; + } + reinit_completion(&done_wait); + tx->callback = scif_dma_callback; + tx->callback_param = &done_wait; + cookie = tx->tx_submit(tx); + + if (dma_submit_error(cookie)) { + err = -ENOMEM; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + goto release; + } + dma_async_issue_pending(chan); + + err = wait_for_completion_timeout(&done_wait, SCIF_DMA_TO); + if (!err) { + err = -EIO; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + goto release; + } + err = 0; + status = dma_async_is_tx_complete(chan, cookie, NULL, NULL); + if (status != DMA_COMPLETE) { + err = -EIO; + dev_err(&sdev->dev, "%s %d err %d\n", + __func__, __LINE__, err); + goto release; + } +release: + return err; +} + +/* + * scif_drain_dma_poll - Drain all outstanding DMA operations for a particular + * DMA channel via polling. + * + * @sdev - The SCIF device + * @chan - DMA channel + * Return 0 on success and -errno on error. + */ +static int scif_drain_dma_poll(struct scif_hw_dev *sdev, struct dma_chan *chan) +{ + if (!chan) + return -EINVAL; + return scif_sync_dma(sdev, chan, SCIF_DMA_SYNC_WAIT); +} + +/* + * scif_drain_dma_intr - Drain all outstanding DMA operations for a particular + * DMA channel via interrupt based blocking wait. + * + * @sdev - The SCIF device + * @chan - DMA channel + * Return 0 on success and -errno on error. + */ +int scif_drain_dma_intr(struct scif_hw_dev *sdev, struct dma_chan *chan) +{ + if (!chan) + return -EINVAL; + return scif_async_dma(sdev, chan); +} + +/** + * scif_rma_destroy_windows: + * + * This routine destroys all windows queued for cleanup + */ +void scif_rma_destroy_windows(void) +{ + struct list_head *item, *tmp; + struct scif_window *window; + struct scif_endpt *ep; + struct dma_chan *chan; + + might_sleep(); +restart: + spin_lock(&scif_info.rmalock); + list_for_each_safe(item, tmp, &scif_info.rma) { + window = list_entry(item, struct scif_window, + list); + ep = (struct scif_endpt *)window->ep; + chan = ep->rma_info.dma_chan; + + list_del_init(&window->list); + spin_unlock(&scif_info.rmalock); + if (!chan || !scifdev_alive(ep) || + !scif_drain_dma_intr(ep->remote_dev->sdev, + ep->rma_info.dma_chan)) + /* Remove window from global list */ + window->unreg_state = OP_COMPLETED; + else + dev_warn(&ep->remote_dev->sdev->dev, + "DMA engine hung?\n"); + if (window->unreg_state == OP_COMPLETED) { + if (window->type == SCIF_WINDOW_SELF) + scif_destroy_window(ep, window); + else + scif_destroy_remote_window(window); + atomic_dec(&ep->rma_info.tw_refcount); + } + goto restart; + } + spin_unlock(&scif_info.rmalock); +} + +/** + * scif_rma_destroy_tcw: + * + * This routine destroys temporary cached registered windows + * which have been queued for cleanup. + */ +void scif_rma_destroy_tcw_invalid(void) +{ + struct list_head *item, *tmp; + struct scif_window *window; + struct scif_endpt *ep; + struct dma_chan *chan; + + might_sleep(); +restart: + spin_lock(&scif_info.rmalock); + list_for_each_safe(item, tmp, &scif_info.rma_tc) { + window = list_entry(item, struct scif_window, list); + ep = (struct scif_endpt *)window->ep; + chan = ep->rma_info.dma_chan; + list_del_init(&window->list); + spin_unlock(&scif_info.rmalock); + mutex_lock(&ep->rma_info.rma_lock); + if (!chan || !scifdev_alive(ep) || + !scif_drain_dma_intr(ep->remote_dev->sdev, + ep->rma_info.dma_chan)) { + atomic_sub(window->nr_pages, + &ep->rma_info.tcw_total_pages); + scif_destroy_window(ep, window); + atomic_dec(&ep->rma_info.tcw_refcount); + } else { + dev_warn(&ep->remote_dev->sdev->dev, + "DMA engine hung?\n"); + } + mutex_unlock(&ep->rma_info.rma_lock); + goto restart; + } + spin_unlock(&scif_info.rmalock); +} + +static inline +void *_get_local_va(off_t off, struct scif_window *window, size_t len) +{ + int page_nr = (off - window->offset) >> PAGE_SHIFT; + off_t page_off = off & ~PAGE_MASK; + void *va = NULL; + + if (window->type == SCIF_WINDOW_SELF) { + struct page **pages = window->pinned_pages->pages; + + va = page_address(pages[page_nr]) + page_off; + } + return va; +} + +static inline +void *ioremap_remote(off_t off, struct scif_window *window, + size_t len, struct scif_dev *dev, + struct scif_window_iter *iter) +{ + dma_addr_t phys = scif_off_to_dma_addr(window, off, NULL, iter); + + /* + * If the DMA address is not card relative then we need the DMA + * addresses to be an offset into the bar. The aperture base was already + * added so subtract it here since scif_ioremap is going to add it again + */ + if (!scifdev_self(dev) && window->type == SCIF_WINDOW_PEER && + dev->sdev->aper && !dev->sdev->card_rel_da) + phys = phys - dev->sdev->aper->pa; + return scif_ioremap(phys, len, dev); +} + +static inline void +iounmap_remote(void *virt, size_t size, struct scif_copy_work *work) +{ + scif_iounmap(virt, size, work->remote_dev); +} + +/* + * Takes care of ordering issue caused by + * 1. Hardware: Only in the case of cpu copy from mgmt node to card + * because of WC memory. + * 2. Software: If memcpy reorders copy instructions for optimization. + * This could happen at both mgmt node and card. + */ +static inline void +scif_ordered_memcpy_toio(char *dst, const char *src, size_t count) +{ + if (!count) + return; + + memcpy_toio((void __iomem __force *)dst, src, --count); + /* Order the last byte with the previous stores */ + wmb(); + *(dst + count) = *(src + count); +} + +static inline void scif_unaligned_cpy_toio(char *dst, const char *src, + size_t count, bool ordered) +{ + if (ordered) + scif_ordered_memcpy_toio(dst, src, count); + else + memcpy_toio((void __iomem __force *)dst, src, count); +} + +static inline +void scif_ordered_memcpy_fromio(char *dst, const char *src, size_t count) +{ + if (!count) + return; + + memcpy_fromio(dst, (void __iomem __force *)src, --count); + /* Order the last byte with the previous loads */ + rmb(); + *(dst + count) = *(src + count); +} + +static inline void scif_unaligned_cpy_fromio(char *dst, const char *src, + size_t count, bool ordered) +{ + if (ordered) + scif_ordered_memcpy_fromio(dst, src, count); + else + memcpy_fromio(dst, (void __iomem __force *)src, count); +} + +#define SCIF_RMA_ERROR_CODE (~(dma_addr_t)0x0) + +/* + * scif_off_to_dma_addr: + * Obtain the dma_addr given the window and the offset. + * @window: Registered window. + * @off: Window offset. + * @nr_bytes: Return the number of contiguous bytes till next DMA addr index. + * @index: Return the index of the dma_addr array found. + * @start_off: start offset of index of the dma addr array found. + * The nr_bytes provides the callee an estimate of the maximum possible + * DMA xfer possible while the index/start_off provide faster lookups + * for the next iteration. + */ +dma_addr_t scif_off_to_dma_addr(struct scif_window *window, s64 off, + size_t *nr_bytes, struct scif_window_iter *iter) +{ + int i, page_nr; + s64 start, end; + off_t page_off; + + if (window->nr_pages == window->nr_contig_chunks) { + page_nr = (off - window->offset) >> PAGE_SHIFT; + page_off = off & ~PAGE_MASK; + + if (nr_bytes) + *nr_bytes = PAGE_SIZE - page_off; + return window->dma_addr[page_nr] | page_off; + } + if (iter) { + i = iter->index; + start = iter->offset; + } else { + i = 0; + start = window->offset; + } + for (; i < window->nr_contig_chunks; i++) { + end = start + (window->num_pages[i] << PAGE_SHIFT); + if (off >= start && off < end) { + if (iter) { + iter->index = i; + iter->offset = start; + } + if (nr_bytes) + *nr_bytes = end - off; + return (window->dma_addr[i] + (off - start)); + } + start += (window->num_pages[i] << PAGE_SHIFT); + } + dev_err(scif_info.mdev.this_device, + "%s %d BUG. Addr not found? window %p off 0x%llx\n", + __func__, __LINE__, window, off); + return SCIF_RMA_ERROR_CODE; +} + +/* + * Copy between rma window and temporary buffer + */ +static void scif_rma_local_cpu_copy(s64 offset, struct scif_window *window, + u8 *temp, size_t rem_len, bool to_temp) +{ + void *window_virt; + size_t loop_len; + int offset_in_page; + s64 end_offset; + + offset_in_page = offset & ~PAGE_MASK; + loop_len = PAGE_SIZE - offset_in_page; + + if (rem_len < loop_len) + loop_len = rem_len; + + window_virt = _get_local_va(offset, window, loop_len); + if (!window_virt) + return; + if (to_temp) + memcpy(temp, window_virt, loop_len); + else + memcpy(window_virt, temp, loop_len); + + offset += loop_len; + temp += loop_len; + rem_len -= loop_len; + + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + while (rem_len) { + if (offset == end_offset) { + window = list_entry_next(window, list); + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + } + loop_len = min(PAGE_SIZE, rem_len); + window_virt = _get_local_va(offset, window, loop_len); + if (!window_virt) + return; + if (to_temp) + memcpy(temp, window_virt, loop_len); + else + memcpy(window_virt, temp, loop_len); + offset += loop_len; + temp += loop_len; + rem_len -= loop_len; + } +} + +/** + * scif_rma_completion_cb: + * @data: RMA cookie + * + * RMA interrupt completion callback. + */ +static void scif_rma_completion_cb(void *data) +{ + struct scif_dma_comp_cb *comp_cb = data; + + /* Free DMA Completion CB. */ + if (comp_cb->dst_window) + scif_rma_local_cpu_copy(comp_cb->dst_offset, + comp_cb->dst_window, + comp_cb->temp_buf + + comp_cb->header_padding, + comp_cb->len, false); + scif_unmap_single(comp_cb->temp_phys, comp_cb->sdev, + SCIF_KMEM_UNALIGNED_BUF_SIZE); + if (comp_cb->is_cache) + kmem_cache_free(unaligned_cache, + comp_cb->temp_buf_to_free); + else + kfree(comp_cb->temp_buf_to_free); +} + +/* Copies between temporary buffer and offsets provided in work */ +static int +scif_rma_list_dma_copy_unaligned(struct scif_copy_work *work, + u8 *temp, struct dma_chan *chan, + bool src_local) +{ + struct scif_dma_comp_cb *comp_cb = work->comp_cb; + dma_addr_t window_dma_addr, temp_dma_addr; + dma_addr_t temp_phys = comp_cb->temp_phys; + size_t loop_len, nr_contig_bytes = 0, remaining_len = work->len; + int offset_in_ca, ret = 0; + s64 end_offset, offset; + struct scif_window *window; + void *window_virt_addr; + size_t tail_len; + struct dma_async_tx_descriptor *tx; + struct dma_device *dev = chan->device; + dma_cookie_t cookie; + + if (src_local) { + offset = work->dst_offset; + window = work->dst_window; + } else { + offset = work->src_offset; + window = work->src_window; + } + + offset_in_ca = offset & (L1_CACHE_BYTES - 1); + if (offset_in_ca) { + loop_len = L1_CACHE_BYTES - offset_in_ca; + loop_len = min(loop_len, remaining_len); + window_virt_addr = ioremap_remote(offset, window, + loop_len, + work->remote_dev, + NULL); + if (!window_virt_addr) + return -ENOMEM; + if (src_local) + scif_unaligned_cpy_toio(window_virt_addr, temp, + loop_len, + work->ordered && + !(remaining_len - loop_len)); + else + scif_unaligned_cpy_fromio(temp, window_virt_addr, + loop_len, work->ordered && + !(remaining_len - loop_len)); + iounmap_remote(window_virt_addr, loop_len, work); + + offset += loop_len; + temp += loop_len; + temp_phys += loop_len; + remaining_len -= loop_len; + } + + offset_in_ca = offset & ~PAGE_MASK; + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + + tail_len = remaining_len & (L1_CACHE_BYTES - 1); + remaining_len -= tail_len; + while (remaining_len) { + if (offset == end_offset) { + window = list_entry_next(window, list); + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + } + if (scif_is_mgmt_node()) + temp_dma_addr = temp_phys; + else + /* Fix if we ever enable IOMMU on the card */ + temp_dma_addr = (dma_addr_t)virt_to_phys(temp); + window_dma_addr = scif_off_to_dma_addr(window, offset, + &nr_contig_bytes, + NULL); + loop_len = min(nr_contig_bytes, remaining_len); + if (src_local) { + if (work->ordered && !tail_len && + !(remaining_len - loop_len) && + loop_len != L1_CACHE_BYTES) { + /* + * Break up the last chunk of the transfer into + * two steps. if there is no tail to guarantee + * DMA ordering. SCIF_DMA_POLLING inserts + * a status update descriptor in step 1 which + * acts as a double sided synchronization fence + * for the DMA engine to ensure that the last + * cache line in step 2 is updated last. + */ + /* Step 1) DMA: Body Length - L1_CACHE_BYTES. */ + tx = + dev->device_prep_dma_memcpy(chan, + window_dma_addr, + temp_dma_addr, + loop_len - + L1_CACHE_BYTES, + DMA_PREP_FENCE); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + offset += (loop_len - L1_CACHE_BYTES); + temp_dma_addr += (loop_len - L1_CACHE_BYTES); + window_dma_addr += (loop_len - L1_CACHE_BYTES); + remaining_len -= (loop_len - L1_CACHE_BYTES); + loop_len = remaining_len; + + /* Step 2) DMA: L1_CACHE_BYTES */ + tx = + dev->device_prep_dma_memcpy(chan, + window_dma_addr, + temp_dma_addr, + loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + } else { + tx = + dev->device_prep_dma_memcpy(chan, + window_dma_addr, + temp_dma_addr, + loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + } + } else { + tx = dev->device_prep_dma_memcpy(chan, temp_dma_addr, + window_dma_addr, loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + } + if (ret < 0) + goto err; + offset += loop_len; + temp += loop_len; + temp_phys += loop_len; + remaining_len -= loop_len; + offset_in_ca = 0; + } + if (tail_len) { + if (offset == end_offset) { + window = list_entry_next(window, list); + end_offset = window->offset + + (window->nr_pages << PAGE_SHIFT); + } + window_virt_addr = ioremap_remote(offset, window, tail_len, + work->remote_dev, + NULL); + if (!window_virt_addr) + return -ENOMEM; + /* + * The CPU copy for the tail bytes must be initiated only once + * previous DMA transfers for this endpoint have completed + * to guarantee ordering. + */ + if (work->ordered) { + struct scif_dev *rdev = work->remote_dev; + + ret = scif_drain_dma_intr(rdev->sdev, chan); + if (ret) + return ret; + } + if (src_local) + scif_unaligned_cpy_toio(window_virt_addr, temp, + tail_len, work->ordered); + else + scif_unaligned_cpy_fromio(temp, window_virt_addr, + tail_len, work->ordered); + iounmap_remote(window_virt_addr, tail_len, work); + } + tx = dev->device_prep_dma_memcpy(chan, 0, 0, 0, DMA_PREP_INTERRUPT); + if (!tx) { + ret = -ENOMEM; + return ret; + } + tx->callback = &scif_rma_completion_cb; + tx->callback_param = comp_cb; + cookie = tx->tx_submit(tx); + + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + return ret; + } + dma_async_issue_pending(chan); + return 0; +err: + dev_err(scif_info.mdev.this_device, + "%s %d Desc Prog Failed ret %d\n", + __func__, __LINE__, ret); + return ret; +} + +/* + * _scif_rma_list_dma_copy_aligned: + * + * Traverse all the windows and perform DMA copy. + */ +static int _scif_rma_list_dma_copy_aligned(struct scif_copy_work *work, + struct dma_chan *chan) +{ + dma_addr_t src_dma_addr, dst_dma_addr; + size_t loop_len, remaining_len, src_contig_bytes = 0; + size_t dst_contig_bytes = 0; + struct scif_window_iter src_win_iter; + struct scif_window_iter dst_win_iter; + s64 end_src_offset, end_dst_offset; + struct scif_window *src_window = work->src_window; + struct scif_window *dst_window = work->dst_window; + s64 src_offset = work->src_offset, dst_offset = work->dst_offset; + int ret = 0; + struct dma_async_tx_descriptor *tx; + struct dma_device *dev = chan->device; + dma_cookie_t cookie; + + remaining_len = work->len; + + scif_init_window_iter(src_window, &src_win_iter); + scif_init_window_iter(dst_window, &dst_win_iter); + end_src_offset = src_window->offset + + (src_window->nr_pages << PAGE_SHIFT); + end_dst_offset = dst_window->offset + + (dst_window->nr_pages << PAGE_SHIFT); + while (remaining_len) { + if (src_offset == end_src_offset) { + src_window = list_entry_next(src_window, list); + end_src_offset = src_window->offset + + (src_window->nr_pages << PAGE_SHIFT); + scif_init_window_iter(src_window, &src_win_iter); + } + if (dst_offset == end_dst_offset) { + dst_window = list_entry_next(dst_window, list); + end_dst_offset = dst_window->offset + + (dst_window->nr_pages << PAGE_SHIFT); + scif_init_window_iter(dst_window, &dst_win_iter); + } + + /* compute dma addresses for transfer */ + src_dma_addr = scif_off_to_dma_addr(src_window, src_offset, + &src_contig_bytes, + &src_win_iter); + dst_dma_addr = scif_off_to_dma_addr(dst_window, dst_offset, + &dst_contig_bytes, + &dst_win_iter); + loop_len = min(src_contig_bytes, dst_contig_bytes); + loop_len = min(loop_len, remaining_len); + if (work->ordered && !(remaining_len - loop_len)) { + /* + * Break up the last chunk of the transfer into two + * steps to ensure that the last byte in step 2 is + * updated last. + */ + /* Step 1) DMA: Body Length - 1 */ + tx = dev->device_prep_dma_memcpy(chan, dst_dma_addr, + src_dma_addr, + loop_len - 1, + DMA_PREP_FENCE); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + src_offset += (loop_len - 1); + dst_offset += (loop_len - 1); + src_dma_addr += (loop_len - 1); + dst_dma_addr += (loop_len - 1); + remaining_len -= (loop_len - 1); + loop_len = remaining_len; + + /* Step 2) DMA: 1 BYTES */ + tx = dev->device_prep_dma_memcpy(chan, dst_dma_addr, + src_dma_addr, loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + } else { + tx = dev->device_prep_dma_memcpy(chan, dst_dma_addr, + src_dma_addr, loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + } + src_offset += loop_len; + dst_offset += loop_len; + remaining_len -= loop_len; + } + return ret; +err: + dev_err(scif_info.mdev.this_device, + "%s %d Desc Prog Failed ret %d\n", + __func__, __LINE__, ret); + return ret; +} + +/* + * scif_rma_list_dma_copy_aligned: + * + * Traverse all the windows and perform DMA copy. + */ +static int scif_rma_list_dma_copy_aligned(struct scif_copy_work *work, + struct dma_chan *chan) +{ + dma_addr_t src_dma_addr, dst_dma_addr; + size_t loop_len, remaining_len, tail_len, src_contig_bytes = 0; + size_t dst_contig_bytes = 0; + int src_cache_off; + s64 end_src_offset, end_dst_offset; + struct scif_window_iter src_win_iter; + struct scif_window_iter dst_win_iter; + void *src_virt, *dst_virt; + struct scif_window *src_window = work->src_window; + struct scif_window *dst_window = work->dst_window; + s64 src_offset = work->src_offset, dst_offset = work->dst_offset; + int ret = 0; + struct dma_async_tx_descriptor *tx; + struct dma_device *dev = chan->device; + dma_cookie_t cookie; + + remaining_len = work->len; + scif_init_window_iter(src_window, &src_win_iter); + scif_init_window_iter(dst_window, &dst_win_iter); + + src_cache_off = src_offset & (L1_CACHE_BYTES - 1); + if (src_cache_off != 0) { + /* Head */ + loop_len = L1_CACHE_BYTES - src_cache_off; + loop_len = min(loop_len, remaining_len); + src_dma_addr = __scif_off_to_dma_addr(src_window, src_offset); + dst_dma_addr = __scif_off_to_dma_addr(dst_window, dst_offset); + if (src_window->type == SCIF_WINDOW_SELF) + src_virt = _get_local_va(src_offset, src_window, + loop_len); + else + src_virt = ioremap_remote(src_offset, src_window, + loop_len, + work->remote_dev, NULL); + if (!src_virt) + return -ENOMEM; + if (dst_window->type == SCIF_WINDOW_SELF) + dst_virt = _get_local_va(dst_offset, dst_window, + loop_len); + else + dst_virt = ioremap_remote(dst_offset, dst_window, + loop_len, + work->remote_dev, NULL); + if (!dst_virt) { + if (src_window->type != SCIF_WINDOW_SELF) + iounmap_remote(src_virt, loop_len, work); + return -ENOMEM; + } + if (src_window->type == SCIF_WINDOW_SELF) + scif_unaligned_cpy_toio(dst_virt, src_virt, loop_len, + remaining_len == loop_len ? + work->ordered : false); + else + scif_unaligned_cpy_fromio(dst_virt, src_virt, loop_len, + remaining_len == loop_len ? + work->ordered : false); + if (src_window->type != SCIF_WINDOW_SELF) + iounmap_remote(src_virt, loop_len, work); + if (dst_window->type != SCIF_WINDOW_SELF) + iounmap_remote(dst_virt, loop_len, work); + src_offset += loop_len; + dst_offset += loop_len; + remaining_len -= loop_len; + } + + end_src_offset = src_window->offset + + (src_window->nr_pages << PAGE_SHIFT); + end_dst_offset = dst_window->offset + + (dst_window->nr_pages << PAGE_SHIFT); + tail_len = remaining_len & (L1_CACHE_BYTES - 1); + remaining_len -= tail_len; + while (remaining_len) { + if (src_offset == end_src_offset) { + src_window = list_entry_next(src_window, list); + end_src_offset = src_window->offset + + (src_window->nr_pages << PAGE_SHIFT); + scif_init_window_iter(src_window, &src_win_iter); + } + if (dst_offset == end_dst_offset) { + dst_window = list_entry_next(dst_window, list); + end_dst_offset = dst_window->offset + + (dst_window->nr_pages << PAGE_SHIFT); + scif_init_window_iter(dst_window, &dst_win_iter); + } + + /* compute dma addresses for transfer */ + src_dma_addr = scif_off_to_dma_addr(src_window, src_offset, + &src_contig_bytes, + &src_win_iter); + dst_dma_addr = scif_off_to_dma_addr(dst_window, dst_offset, + &dst_contig_bytes, + &dst_win_iter); + loop_len = min(src_contig_bytes, dst_contig_bytes); + loop_len = min(loop_len, remaining_len); + if (work->ordered && !tail_len && + !(remaining_len - loop_len)) { + /* + * Break up the last chunk of the transfer into two + * steps. if there is no tail to gurantee DMA ordering. + * Passing SCIF_DMA_POLLING inserts a status update + * descriptor in step 1 which acts as a double sided + * synchronization fence for the DMA engine to ensure + * that the last cache line in step 2 is updated last. + */ + /* Step 1) DMA: Body Length - L1_CACHE_BYTES. */ + tx = dev->device_prep_dma_memcpy(chan, dst_dma_addr, + src_dma_addr, + loop_len - + L1_CACHE_BYTES, + DMA_PREP_FENCE); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + src_offset += (loop_len - L1_CACHE_BYTES); + dst_offset += (loop_len - L1_CACHE_BYTES); + src_dma_addr += (loop_len - L1_CACHE_BYTES); + dst_dma_addr += (loop_len - L1_CACHE_BYTES); + remaining_len -= (loop_len - L1_CACHE_BYTES); + loop_len = remaining_len; + + /* Step 2) DMA: L1_CACHE_BYTES */ + tx = dev->device_prep_dma_memcpy(chan, dst_dma_addr, + src_dma_addr, + loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + } else { + tx = dev->device_prep_dma_memcpy(chan, dst_dma_addr, + src_dma_addr, + loop_len, 0); + if (!tx) { + ret = -ENOMEM; + goto err; + } + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + ret = -ENOMEM; + goto err; + } + dma_async_issue_pending(chan); + } + src_offset += loop_len; + dst_offset += loop_len; + remaining_len -= loop_len; + } + remaining_len = tail_len; + if (remaining_len) { + loop_len = remaining_len; + if (src_offset == end_src_offset) + src_window = list_entry_next(src_window, list); + if (dst_offset == end_dst_offset) + dst_window = list_entry_next(dst_window, list); + + src_dma_addr = __scif_off_to_dma_addr(src_window, src_offset); + dst_dma_addr = __scif_off_to_dma_addr(dst_window, dst_offset); + /* + * The CPU copy for the tail bytes must be initiated only once + * previous DMA transfers for this endpoint have completed to + * guarantee ordering. + */ + if (work->ordered) { + struct scif_dev *rdev = work->remote_dev; + + ret = scif_drain_dma_poll(rdev->sdev, chan); + if (ret) + return ret; + } + if (src_window->type == SCIF_WINDOW_SELF) + src_virt = _get_local_va(src_offset, src_window, + loop_len); + else + src_virt = ioremap_remote(src_offset, src_window, + loop_len, + work->remote_dev, NULL); + if (!src_virt) + return -ENOMEM; + + if (dst_window->type == SCIF_WINDOW_SELF) + dst_virt = _get_local_va(dst_offset, dst_window, + loop_len); + else + dst_virt = ioremap_remote(dst_offset, dst_window, + loop_len, + work->remote_dev, NULL); + if (!dst_virt) { + if (src_window->type != SCIF_WINDOW_SELF) + iounmap_remote(src_virt, loop_len, work); + return -ENOMEM; + } + + if (src_window->type == SCIF_WINDOW_SELF) + scif_unaligned_cpy_toio(dst_virt, src_virt, loop_len, + work->ordered); + else + scif_unaligned_cpy_fromio(dst_virt, src_virt, + loop_len, work->ordered); + if (src_window->type != SCIF_WINDOW_SELF) + iounmap_remote(src_virt, loop_len, work); + + if (dst_window->type != SCIF_WINDOW_SELF) + iounmap_remote(dst_virt, loop_len, work); + remaining_len -= loop_len; + } + return ret; +err: + dev_err(scif_info.mdev.this_device, + "%s %d Desc Prog Failed ret %d\n", + __func__, __LINE__, ret); + return ret; +} + +/* + * scif_rma_list_cpu_copy: + * + * Traverse all the windows and perform CPU copy. + */ +static int scif_rma_list_cpu_copy(struct scif_copy_work *work) +{ + void *src_virt, *dst_virt; + size_t loop_len, remaining_len; + int src_page_off, dst_page_off; + s64 src_offset = work->src_offset, dst_offset = work->dst_offset; + struct scif_window *src_window = work->src_window; + struct scif_window *dst_window = work->dst_window; + s64 end_src_offset, end_dst_offset; + int ret = 0; + struct scif_window_iter src_win_iter; + struct scif_window_iter dst_win_iter; + + remaining_len = work->len; + + scif_init_window_iter(src_window, &src_win_iter); + scif_init_window_iter(dst_window, &dst_win_iter); + while (remaining_len) { + src_page_off = src_offset & ~PAGE_MASK; + dst_page_off = dst_offset & ~PAGE_MASK; + loop_len = min(PAGE_SIZE - + max(src_page_off, dst_page_off), + remaining_len); + + if (src_window->type == SCIF_WINDOW_SELF) + src_virt = _get_local_va(src_offset, src_window, + loop_len); + else + src_virt = ioremap_remote(src_offset, src_window, + loop_len, + work->remote_dev, + &src_win_iter); + if (!src_virt) { + ret = -ENOMEM; + goto error; + } + + if (dst_window->type == SCIF_WINDOW_SELF) + dst_virt = _get_local_va(dst_offset, dst_window, + loop_len); + else + dst_virt = ioremap_remote(dst_offset, dst_window, + loop_len, + work->remote_dev, + &dst_win_iter); + if (!dst_virt) { + if (src_window->type == SCIF_WINDOW_PEER) + iounmap_remote(src_virt, loop_len, work); + ret = -ENOMEM; + goto error; + } + + if (work->loopback) { + memcpy(dst_virt, src_virt, loop_len); + } else { + if (src_window->type == SCIF_WINDOW_SELF) + memcpy_toio((void __iomem __force *)dst_virt, + src_virt, loop_len); + else + memcpy_fromio(dst_virt, + (void __iomem __force *)src_virt, + loop_len); + } + if (src_window->type == SCIF_WINDOW_PEER) + iounmap_remote(src_virt, loop_len, work); + + if (dst_window->type == SCIF_WINDOW_PEER) + iounmap_remote(dst_virt, loop_len, work); + + src_offset += loop_len; + dst_offset += loop_len; + remaining_len -= loop_len; + if (remaining_len) { + end_src_offset = src_window->offset + + (src_window->nr_pages << PAGE_SHIFT); + end_dst_offset = dst_window->offset + + (dst_window->nr_pages << PAGE_SHIFT); + if (src_offset == end_src_offset) { + src_window = list_entry_next(src_window, list); + scif_init_window_iter(src_window, + &src_win_iter); + } + if (dst_offset == end_dst_offset) { + dst_window = list_entry_next(dst_window, list); + scif_init_window_iter(dst_window, + &dst_win_iter); + } + } + } +error: + return ret; +} + +static int scif_rma_list_dma_copy_wrapper(struct scif_endpt *epd, + struct scif_copy_work *work, + struct dma_chan *chan, off_t loffset) +{ + int src_cache_off, dst_cache_off; + s64 src_offset = work->src_offset, dst_offset = work->dst_offset; + u8 *temp = NULL; + bool src_local = true, dst_local = false; + struct scif_dma_comp_cb *comp_cb; + dma_addr_t src_dma_addr, dst_dma_addr; + int err; + + if (is_dma_copy_aligned(chan->device, 1, 1, 1)) + return _scif_rma_list_dma_copy_aligned(work, chan); + + src_cache_off = src_offset & (L1_CACHE_BYTES - 1); + dst_cache_off = dst_offset & (L1_CACHE_BYTES - 1); + + if (dst_cache_off == src_cache_off) + return scif_rma_list_dma_copy_aligned(work, chan); + + if (work->loopback) + return scif_rma_list_cpu_copy(work); + src_dma_addr = __scif_off_to_dma_addr(work->src_window, src_offset); + dst_dma_addr = __scif_off_to_dma_addr(work->dst_window, dst_offset); + src_local = work->src_window->type == SCIF_WINDOW_SELF; + dst_local = work->dst_window->type == SCIF_WINDOW_SELF; + + dst_local = dst_local; + /* Allocate dma_completion cb */ + comp_cb = kzalloc(sizeof(*comp_cb), GFP_KERNEL); + if (!comp_cb) + goto error; + + work->comp_cb = comp_cb; + comp_cb->cb_cookie = comp_cb; + comp_cb->dma_completion_func = &scif_rma_completion_cb; + + if (work->len + (L1_CACHE_BYTES << 1) < SCIF_KMEM_UNALIGNED_BUF_SIZE) { + comp_cb->is_cache = false; + /* Allocate padding bytes to align to a cache line */ + temp = kmalloc(work->len + (L1_CACHE_BYTES << 1), + GFP_KERNEL); + if (!temp) + goto free_comp_cb; + comp_cb->temp_buf_to_free = temp; + /* kmalloc(..) does not guarantee cache line alignment */ + if (!IS_ALIGNED((u64)temp, L1_CACHE_BYTES)) + temp = PTR_ALIGN(temp, L1_CACHE_BYTES); + } else { + comp_cb->is_cache = true; + temp = kmem_cache_alloc(unaligned_cache, GFP_KERNEL); + if (!temp) + goto free_comp_cb; + comp_cb->temp_buf_to_free = temp; + } + + if (src_local) { + temp += dst_cache_off; + scif_rma_local_cpu_copy(work->src_offset, work->src_window, + temp, work->len, true); + } else { + comp_cb->dst_window = work->dst_window; + comp_cb->dst_offset = work->dst_offset; + work->src_offset = work->src_offset - src_cache_off; + comp_cb->len = work->len; + work->len = ALIGN(work->len + src_cache_off, L1_CACHE_BYTES); + comp_cb->header_padding = src_cache_off; + } + comp_cb->temp_buf = temp; + + err = scif_map_single(&comp_cb->temp_phys, temp, + work->remote_dev, SCIF_KMEM_UNALIGNED_BUF_SIZE); + if (err) + goto free_temp_buf; + comp_cb->sdev = work->remote_dev; + if (scif_rma_list_dma_copy_unaligned(work, temp, chan, src_local) < 0) + goto free_temp_buf; + if (!src_local) + work->fence_type = SCIF_DMA_INTR; + return 0; +free_temp_buf: + if (comp_cb->is_cache) + kmem_cache_free(unaligned_cache, comp_cb->temp_buf_to_free); + else + kfree(comp_cb->temp_buf_to_free); +free_comp_cb: + kfree(comp_cb); +error: + return -ENOMEM; +} + +/** + * scif_rma_copy: + * @epd: end point descriptor. + * @loffset: offset in local registered address space to/from which to copy + * @addr: user virtual address to/from which to copy + * @len: length of range to copy + * @roffset: offset in remote registered address space to/from which to copy + * @flags: flags + * @dir: LOCAL->REMOTE or vice versa. + * @last_chunk: true if this is the last chunk of a larger transfer + * + * Validate parameters, check if src/dst registered ranges requested for copy + * are valid and initiate either CPU or DMA copy. + */ +static int scif_rma_copy(scif_epd_t epd, off_t loffset, unsigned long addr, + size_t len, off_t roffset, int flags, + enum scif_rma_dir dir, bool last_chunk) +{ + struct scif_endpt *ep = (struct scif_endpt *)epd; + struct scif_rma_req remote_req; + struct scif_rma_req req; + struct scif_window *local_window = NULL; + struct scif_window *remote_window = NULL; + struct scif_copy_work copy_work; + bool loopback; + int err = 0; + struct dma_chan *chan; + struct scif_mmu_notif *mmn = NULL; + bool cache = false; + struct device *spdev; + + err = scif_verify_epd(ep); + if (err) + return err; + + if (flags && !(flags & (SCIF_RMA_USECPU | SCIF_RMA_USECACHE | + SCIF_RMA_SYNC | SCIF_RMA_ORDERED))) + return -EINVAL; + + loopback = scifdev_self(ep->remote_dev) ? true : false; + copy_work.fence_type = ((flags & SCIF_RMA_SYNC) && last_chunk) ? + SCIF_DMA_POLL : 0; + copy_work.ordered = !!((flags & SCIF_RMA_ORDERED) && last_chunk); + + /* Use CPU for Mgmt node <-> Mgmt node copies */ + if (loopback && scif_is_mgmt_node()) { + flags |= SCIF_RMA_USECPU; + copy_work.fence_type = 0x0; + } + + cache = scif_is_set_reg_cache(flags); + + remote_req.out_window = &remote_window; + remote_req.offset = roffset; + remote_req.nr_bytes = len; + /* + * If transfer is from local to remote then the remote window + * must be writeable and vice versa. + */ + remote_req.prot = dir == SCIF_LOCAL_TO_REMOTE ? VM_WRITE : VM_READ; + remote_req.type = SCIF_WINDOW_PARTIAL; + remote_req.head = &ep->rma_info.remote_reg_list; + + spdev = scif_get_peer_dev(ep->remote_dev); + if (IS_ERR(spdev)) { + err = PTR_ERR(spdev); + return err; + } + + if (addr && cache) { + mutex_lock(&ep->rma_info.mmn_lock); + mmn = scif_find_mmu_notifier(current->mm, &ep->rma_info); + if (!mmn) + scif_add_mmu_notifier(current->mm, ep); + mutex_unlock(&ep->rma_info.mmn_lock); + if (IS_ERR(mmn)) { + scif_put_peer_dev(spdev); + return PTR_ERR(mmn); + } + cache = cache && !scif_rma_tc_can_cache(ep, len); + } + mutex_lock(&ep->rma_info.rma_lock); + if (addr) { + req.out_window = &local_window; + req.nr_bytes = ALIGN(len + (addr & ~PAGE_MASK), + PAGE_SIZE); + req.va_for_temp = addr & PAGE_MASK; + req.prot = (dir == SCIF_LOCAL_TO_REMOTE ? + VM_READ : VM_WRITE | VM_READ); + /* Does a valid local window exist? */ + if (mmn) { + spin_lock(&ep->rma_info.tc_lock); + req.head = &mmn->tc_reg_list; + err = scif_query_tcw(ep, &req); + spin_unlock(&ep->rma_info.tc_lock); + } + if (!mmn || err) { + err = scif_register_temp(epd, req.va_for_temp, + req.nr_bytes, req.prot, + &loffset, &local_window); + if (err) { + mutex_unlock(&ep->rma_info.rma_lock); + goto error; + } + if (!cache) + goto skip_cache; + atomic_inc(&ep->rma_info.tcw_refcount); + atomic_add_return(local_window->nr_pages, + &ep->rma_info.tcw_total_pages); + if (mmn) { + spin_lock(&ep->rma_info.tc_lock); + scif_insert_tcw(local_window, + &mmn->tc_reg_list); + spin_unlock(&ep->rma_info.tc_lock); + } + } +skip_cache: + loffset = local_window->offset + + (addr - local_window->va_for_temp); + } else { + req.out_window = &local_window; + req.offset = loffset; + /* + * If transfer is from local to remote then the self window + * must be readable and vice versa. + */ + req.prot = dir == SCIF_LOCAL_TO_REMOTE ? VM_READ : VM_WRITE; + req.nr_bytes = len; + req.type = SCIF_WINDOW_PARTIAL; + req.head = &ep->rma_info.reg_list; + /* Does a valid local window exist? */ + err = scif_query_window(&req); + if (err) { + mutex_unlock(&ep->rma_info.rma_lock); + goto error; + } + } + + /* Does a valid remote window exist? */ + err = scif_query_window(&remote_req); + if (err) { + mutex_unlock(&ep->rma_info.rma_lock); + goto error; + } + + /* + * Prepare copy_work for submitting work to the DMA kernel thread + * or CPU copy routine. + */ + copy_work.len = len; + copy_work.loopback = loopback; + copy_work.remote_dev = ep->remote_dev; + if (dir == SCIF_LOCAL_TO_REMOTE) { + copy_work.src_offset = loffset; + copy_work.src_window = local_window; + copy_work.dst_offset = roffset; + copy_work.dst_window = remote_window; + } else { + copy_work.src_offset = roffset; + copy_work.src_window = remote_window; + copy_work.dst_offset = loffset; + copy_work.dst_window = local_window; + } + + if (flags & SCIF_RMA_USECPU) { + scif_rma_list_cpu_copy(©_work); + } else { + chan = ep->rma_info.dma_chan; + err = scif_rma_list_dma_copy_wrapper(epd, ©_work, + chan, loffset); + } + if (addr && !cache) + atomic_inc(&ep->rma_info.tw_refcount); + + mutex_unlock(&ep->rma_info.rma_lock); + + if (last_chunk) { + struct scif_dev *rdev = ep->remote_dev; + + if (copy_work.fence_type == SCIF_DMA_POLL) + err = scif_drain_dma_poll(rdev->sdev, + ep->rma_info.dma_chan); + else if (copy_work.fence_type == SCIF_DMA_INTR) + err = scif_drain_dma_intr(rdev->sdev, + ep->rma_info.dma_chan); + } + + if (addr && !cache) + scif_queue_for_cleanup(local_window, &scif_info.rma); + scif_put_peer_dev(spdev); + return err; +error: + if (err) { + if (addr && local_window && !cache) + scif_destroy_window(ep, local_window); + dev_err(scif_info.mdev.this_device, + "%s %d err %d len 0x%lx\n", + __func__, __LINE__, err, len); + } + scif_put_peer_dev(spdev); + return err; +} + +int scif_readfrom(scif_epd_t epd, off_t loffset, size_t len, + off_t roffset, int flags) +{ + int err; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI readfrom: ep %p loffset 0x%lx len 0x%lx offset 0x%lx flags 0x%x\n", + epd, loffset, len, roffset, flags); + if (scif_unaligned(loffset, roffset)) { + while (len > SCIF_MAX_UNALIGNED_BUF_SIZE) { + err = scif_rma_copy(epd, loffset, 0x0, + SCIF_MAX_UNALIGNED_BUF_SIZE, + roffset, flags, + SCIF_REMOTE_TO_LOCAL, false); + if (err) + goto readfrom_err; + loffset += SCIF_MAX_UNALIGNED_BUF_SIZE; + roffset += SCIF_MAX_UNALIGNED_BUF_SIZE; + len -= SCIF_MAX_UNALIGNED_BUF_SIZE; + } + } + err = scif_rma_copy(epd, loffset, 0x0, len, + roffset, flags, SCIF_REMOTE_TO_LOCAL, true); +readfrom_err: + return err; +} +EXPORT_SYMBOL_GPL(scif_readfrom); + +int scif_writeto(scif_epd_t epd, off_t loffset, size_t len, + off_t roffset, int flags) +{ + int err; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI writeto: ep %p loffset 0x%lx len 0x%lx roffset 0x%lx flags 0x%x\n", + epd, loffset, len, roffset, flags); + if (scif_unaligned(loffset, roffset)) { + while (len > SCIF_MAX_UNALIGNED_BUF_SIZE) { + err = scif_rma_copy(epd, loffset, 0x0, + SCIF_MAX_UNALIGNED_BUF_SIZE, + roffset, flags, + SCIF_LOCAL_TO_REMOTE, false); + if (err) + goto writeto_err; + loffset += SCIF_MAX_UNALIGNED_BUF_SIZE; + roffset += SCIF_MAX_UNALIGNED_BUF_SIZE; + len -= SCIF_MAX_UNALIGNED_BUF_SIZE; + } + } + err = scif_rma_copy(epd, loffset, 0x0, len, + roffset, flags, SCIF_LOCAL_TO_REMOTE, true); +writeto_err: + return err; +} +EXPORT_SYMBOL_GPL(scif_writeto); + +int scif_vreadfrom(scif_epd_t epd, void *addr, size_t len, + off_t roffset, int flags) +{ + int err; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI vreadfrom: ep %p addr %p len 0x%lx roffset 0x%lx flags 0x%x\n", + epd, addr, len, roffset, flags); + if (scif_unaligned((off_t __force)addr, roffset)) { + if (len > SCIF_MAX_UNALIGNED_BUF_SIZE) + flags &= ~SCIF_RMA_USECACHE; + + while (len > SCIF_MAX_UNALIGNED_BUF_SIZE) { + err = scif_rma_copy(epd, 0, (u64)addr, + SCIF_MAX_UNALIGNED_BUF_SIZE, + roffset, flags, + SCIF_REMOTE_TO_LOCAL, false); + if (err) + goto vreadfrom_err; + addr += SCIF_MAX_UNALIGNED_BUF_SIZE; + roffset += SCIF_MAX_UNALIGNED_BUF_SIZE; + len -= SCIF_MAX_UNALIGNED_BUF_SIZE; + } + } + err = scif_rma_copy(epd, 0, (u64)addr, len, + roffset, flags, SCIF_REMOTE_TO_LOCAL, true); +vreadfrom_err: + return err; +} +EXPORT_SYMBOL_GPL(scif_vreadfrom); + +int scif_vwriteto(scif_epd_t epd, void *addr, size_t len, + off_t roffset, int flags) +{ + int err; + + dev_dbg(scif_info.mdev.this_device, + "SCIFAPI vwriteto: ep %p addr %p len 0x%lx roffset 0x%lx flags 0x%x\n", + epd, addr, len, roffset, flags); + if (scif_unaligned((off_t __force)addr, roffset)) { + if (len > SCIF_MAX_UNALIGNED_BUF_SIZE) + flags &= ~SCIF_RMA_USECACHE; + + while (len > SCIF_MAX_UNALIGNED_BUF_SIZE) { + err = scif_rma_copy(epd, 0, (u64)addr, + SCIF_MAX_UNALIGNED_BUF_SIZE, + roffset, flags, + SCIF_LOCAL_TO_REMOTE, false); + if (err) + goto vwriteto_err; + addr += SCIF_MAX_UNALIGNED_BUF_SIZE; + roffset += SCIF_MAX_UNALIGNED_BUF_SIZE; + len -= SCIF_MAX_UNALIGNED_BUF_SIZE; + } + } + err = scif_rma_copy(epd, 0, (u64)addr, len, + roffset, flags, SCIF_LOCAL_TO_REMOTE, true); +vwriteto_err: + return err; +} +EXPORT_SYMBOL_GPL(scif_vwriteto); 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