Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Hao Wu | 1331 | 91.04% | 3 | 30.00% |
Xiao Guangrong | 106 | 7.25% | 1 | 10.00% |
Daniel Jordan | 12 | 0.82% | 1 | 10.00% |
John Hubbard | 5 | 0.34% | 1 | 10.00% |
Scott Wood | 3 | 0.21% | 1 | 10.00% |
Andrew Morton | 3 | 0.21% | 1 | 10.00% |
Souptick Joarder | 1 | 0.07% | 1 | 10.00% |
Ira Weiny | 1 | 0.07% | 1 | 10.00% |
Total | 1462 | 10 |
// SPDX-License-Identifier: GPL-2.0 /* * Driver for FPGA Accelerated Function Unit (AFU) DMA Region Management * * Copyright (C) 2017-2018 Intel Corporation, Inc. * * Authors: * Wu Hao <hao.wu@intel.com> * Xiao Guangrong <guangrong.xiao@linux.intel.com> */ #include <linux/dma-mapping.h> #include <linux/sched/signal.h> #include <linux/uaccess.h> #include <linux/mm.h> #include "dfl-afu.h" void afu_dma_region_init(struct dfl_feature_platform_data *pdata) { struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata); afu->dma_regions = RB_ROOT; } /** * afu_dma_pin_pages - pin pages of given dma memory region * @pdata: feature device platform data * @region: dma memory region to be pinned * * Pin all the pages of given dfl_afu_dma_region. * Return 0 for success or negative error code. */ static int afu_dma_pin_pages(struct dfl_feature_platform_data *pdata, struct dfl_afu_dma_region *region) { int npages = region->length >> PAGE_SHIFT; struct device *dev = &pdata->dev->dev; int ret, pinned; ret = account_locked_vm(current->mm, npages, true); if (ret) return ret; region->pages = kcalloc(npages, sizeof(struct page *), GFP_KERNEL); if (!region->pages) { ret = -ENOMEM; goto unlock_vm; } pinned = pin_user_pages_fast(region->user_addr, npages, FOLL_WRITE, region->pages); if (pinned < 0) { ret = pinned; goto free_pages; } else if (pinned != npages) { ret = -EFAULT; goto unpin_pages; } dev_dbg(dev, "%d pages pinned\n", pinned); return 0; unpin_pages: unpin_user_pages(region->pages, pinned); free_pages: kfree(region->pages); unlock_vm: account_locked_vm(current->mm, npages, false); return ret; } /** * afu_dma_unpin_pages - unpin pages of given dma memory region * @pdata: feature device platform data * @region: dma memory region to be unpinned * * Unpin all the pages of given dfl_afu_dma_region. * Return 0 for success or negative error code. */ static void afu_dma_unpin_pages(struct dfl_feature_platform_data *pdata, struct dfl_afu_dma_region *region) { long npages = region->length >> PAGE_SHIFT; struct device *dev = &pdata->dev->dev; unpin_user_pages(region->pages, npages); kfree(region->pages); account_locked_vm(current->mm, npages, false); dev_dbg(dev, "%ld pages unpinned\n", npages); } /** * afu_dma_check_continuous_pages - check if pages are continuous * @region: dma memory region * * Return true if pages of given dma memory region have continuous physical * address, otherwise return false. */ static bool afu_dma_check_continuous_pages(struct dfl_afu_dma_region *region) { int npages = region->length >> PAGE_SHIFT; int i; for (i = 0; i < npages - 1; i++) if (page_to_pfn(region->pages[i]) + 1 != page_to_pfn(region->pages[i + 1])) return false; return true; } /** * dma_region_check_iova - check if memory area is fully contained in the region * @region: dma memory region * @iova: address of the dma memory area * @size: size of the dma memory area * * Compare the dma memory area defined by @iova and @size with given dma region. * Return true if memory area is fully contained in the region, otherwise false. */ static bool dma_region_check_iova(struct dfl_afu_dma_region *region, u64 iova, u64 size) { if (!size && region->iova != iova) return false; return (region->iova <= iova) && (region->length + region->iova >= iova + size); } /** * afu_dma_region_add - add given dma region to rbtree * @pdata: feature device platform data * @region: dma region to be added * * Return 0 for success, -EEXIST if dma region has already been added. * * Needs to be called with pdata->lock heold. */ static int afu_dma_region_add(struct dfl_feature_platform_data *pdata, struct dfl_afu_dma_region *region) { struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata); struct rb_node **new, *parent = NULL; dev_dbg(&pdata->dev->dev, "add region (iova = %llx)\n", (unsigned long long)region->iova); new = &afu->dma_regions.rb_node; while (*new) { struct dfl_afu_dma_region *this; this = container_of(*new, struct dfl_afu_dma_region, node); parent = *new; if (dma_region_check_iova(this, region->iova, region->length)) return -EEXIST; if (region->iova < this->iova) new = &((*new)->rb_left); else if (region->iova > this->iova) new = &((*new)->rb_right); else return -EEXIST; } rb_link_node(®ion->node, parent, new); rb_insert_color(®ion->node, &afu->dma_regions); return 0; } /** * afu_dma_region_remove - remove given dma region from rbtree * @pdata: feature device platform data * @region: dma region to be removed * * Needs to be called with pdata->lock heold. */ static void afu_dma_region_remove(struct dfl_feature_platform_data *pdata, struct dfl_afu_dma_region *region) { struct dfl_afu *afu; dev_dbg(&pdata->dev->dev, "del region (iova = %llx)\n", (unsigned long long)region->iova); afu = dfl_fpga_pdata_get_private(pdata); rb_erase(®ion->node, &afu->dma_regions); } /** * afu_dma_region_destroy - destroy all regions in rbtree * @pdata: feature device platform data * * Needs to be called with pdata->lock heold. */ void afu_dma_region_destroy(struct dfl_feature_platform_data *pdata) { struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata); struct rb_node *node = rb_first(&afu->dma_regions); struct dfl_afu_dma_region *region; while (node) { region = container_of(node, struct dfl_afu_dma_region, node); dev_dbg(&pdata->dev->dev, "del region (iova = %llx)\n", (unsigned long long)region->iova); rb_erase(node, &afu->dma_regions); if (region->iova) dma_unmap_page(dfl_fpga_pdata_to_parent(pdata), region->iova, region->length, DMA_BIDIRECTIONAL); if (region->pages) afu_dma_unpin_pages(pdata, region); node = rb_next(node); kfree(region); } } /** * afu_dma_region_find - find the dma region from rbtree based on iova and size * @pdata: feature device platform data * @iova: address of the dma memory area * @size: size of the dma memory area * * It finds the dma region from the rbtree based on @iova and @size: * - if @size == 0, it finds the dma region which starts from @iova * - otherwise, it finds the dma region which fully contains * [@iova, @iova+size) * If nothing is matched returns NULL. * * Needs to be called with pdata->lock held. */ struct dfl_afu_dma_region * afu_dma_region_find(struct dfl_feature_platform_data *pdata, u64 iova, u64 size) { struct dfl_afu *afu = dfl_fpga_pdata_get_private(pdata); struct rb_node *node = afu->dma_regions.rb_node; struct device *dev = &pdata->dev->dev; while (node) { struct dfl_afu_dma_region *region; region = container_of(node, struct dfl_afu_dma_region, node); if (dma_region_check_iova(region, iova, size)) { dev_dbg(dev, "find region (iova = %llx)\n", (unsigned long long)region->iova); return region; } if (iova < region->iova) node = node->rb_left; else if (iova > region->iova) node = node->rb_right; else /* the iova region is not fully covered. */ break; } dev_dbg(dev, "region with iova %llx and size %llx is not found\n", (unsigned long long)iova, (unsigned long long)size); return NULL; } /** * afu_dma_region_find_iova - find the dma region from rbtree by iova * @pdata: feature device platform data * @iova: address of the dma region * * Needs to be called with pdata->lock held. */ static struct dfl_afu_dma_region * afu_dma_region_find_iova(struct dfl_feature_platform_data *pdata, u64 iova) { return afu_dma_region_find(pdata, iova, 0); } /** * afu_dma_map_region - map memory region for dma * @pdata: feature device platform data * @user_addr: address of the memory region * @length: size of the memory region * @iova: pointer of iova address * * Map memory region defined by @user_addr and @length, and return dma address * of the memory region via @iova. * Return 0 for success, otherwise error code. */ int afu_dma_map_region(struct dfl_feature_platform_data *pdata, u64 user_addr, u64 length, u64 *iova) { struct dfl_afu_dma_region *region; int ret; /* * Check Inputs, only accept page-aligned user memory region with * valid length. */ if (!PAGE_ALIGNED(user_addr) || !PAGE_ALIGNED(length) || !length) return -EINVAL; /* Check overflow */ if (user_addr + length < user_addr) return -EINVAL; region = kzalloc(sizeof(*region), GFP_KERNEL); if (!region) return -ENOMEM; region->user_addr = user_addr; region->length = length; /* Pin the user memory region */ ret = afu_dma_pin_pages(pdata, region); if (ret) { dev_err(&pdata->dev->dev, "failed to pin memory region\n"); goto free_region; } /* Only accept continuous pages, return error else */ if (!afu_dma_check_continuous_pages(region)) { dev_err(&pdata->dev->dev, "pages are not continuous\n"); ret = -EINVAL; goto unpin_pages; } /* As pages are continuous then start to do DMA mapping */ region->iova = dma_map_page(dfl_fpga_pdata_to_parent(pdata), region->pages[0], 0, region->length, DMA_BIDIRECTIONAL); if (dma_mapping_error(dfl_fpga_pdata_to_parent(pdata), region->iova)) { dev_err(&pdata->dev->dev, "failed to map for dma\n"); ret = -EFAULT; goto unpin_pages; } *iova = region->iova; mutex_lock(&pdata->lock); ret = afu_dma_region_add(pdata, region); mutex_unlock(&pdata->lock); if (ret) { dev_err(&pdata->dev->dev, "failed to add dma region\n"); goto unmap_dma; } return 0; unmap_dma: dma_unmap_page(dfl_fpga_pdata_to_parent(pdata), region->iova, region->length, DMA_BIDIRECTIONAL); unpin_pages: afu_dma_unpin_pages(pdata, region); free_region: kfree(region); return ret; } /** * afu_dma_unmap_region - unmap dma memory region * @pdata: feature device platform data * @iova: dma address of the region * * Unmap dma memory region based on @iova. * Return 0 for success, otherwise error code. */ int afu_dma_unmap_region(struct dfl_feature_platform_data *pdata, u64 iova) { struct dfl_afu_dma_region *region; mutex_lock(&pdata->lock); region = afu_dma_region_find_iova(pdata, iova); if (!region) { mutex_unlock(&pdata->lock); return -EINVAL; } if (region->in_use) { mutex_unlock(&pdata->lock); return -EBUSY; } afu_dma_region_remove(pdata, region); mutex_unlock(&pdata->lock); dma_unmap_page(dfl_fpga_pdata_to_parent(pdata), region->iova, region->length, DMA_BIDIRECTIONAL); afu_dma_unpin_pages(pdata, region); kfree(region); return 0; }
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